Merge branch 'master' into prototype-fmt

22 files changed, 3271 insertions, 2154 deletions

diff --git a/src/build_settings.cpp b/src/build_settings.cpp
index 82ed24f83..0207221bc 100644
--- a/src/build_settings.cpp
+++ b/src/build_settings.cpp
@@ -173,8 +173,6 @@ struct BuildContext {
 	String resource_filepath;
 	String pdb_filepath;
 	bool   has_resource;
-	String opt_flags;
-	String llc_flags;
 	String link_flags;
 	String extra_linker_flags;
 	String microarch;
@@ -202,18 +200,24 @@ struct BuildContext {
 	bool   disallow_do;
 	bool   insert_semicolon;
 
+
 	bool   ignore_warnings;
 	bool   warnings_as_errors;
+	bool   show_error_line;
 
 	bool   use_subsystem_windows;
 	bool   ignore_microsoft_magic;
 	bool   linker_map_file;
 
+	bool use_separate_modules;
+
 	u32 cmd_doc_flags;
 	Array<String> extra_packages;
 
 	QueryDataSetSettings query_data_set_settings;
 
+	StringSet test_names;
+
 	gbAffinity affinity;
 	isize      thread_count;
 
@@ -744,6 +748,9 @@ String get_fullpath_core(gbAllocator a, String path) {
 	return path_to_fullpath(a, res);
 }
 
+bool show_error_line(void) {
+	return build_context.show_error_line;
+}
 
 
 void init_build_context(TargetMetrics *cross_target) {
@@ -806,22 +813,12 @@ void init_build_context(TargetMetrics *cross_target) {
 	bc->word_size   = metrics->word_size;
 	bc->max_align   = metrics->max_align;
 	bc->link_flags  = str_lit(" ");
-	bc->opt_flags   = str_lit(" ");
 
 
-	gbString llc_flags = gb_string_make_reserve(heap_allocator(), 64);
-	if (bc->ODIN_DEBUG) {
-		// llc_flags = gb_string_appendc(llc_flags, "-debug-compile ");
-	}
-
 	// NOTE(zangent): The linker flags to set the build architecture are different
 	// across OSs. It doesn't make sense to allocate extra data on the heap
 	// here, so I just #defined the linker flags to keep things concise.
 	if (bc->metrics.arch == TargetArch_amd64) {
-		if (bc->microarch.len == 0) {
-			llc_flags = gb_string_appendc(llc_flags, "-march=x86-64 ");
-		}
-
 		switch (bc->metrics.os) {
 		case TargetOs_windows:
 			bc->link_flags = str_lit("/machine:x64 ");
@@ -836,10 +833,6 @@ void init_build_context(TargetMetrics *cross_target) {
 			break;
 		}
 	} else if (bc->metrics.arch == TargetArch_386) {
-		if (bc->microarch.len == 0) {
-			llc_flags = gb_string_appendc(llc_flags, "-march=x86 ");
-		}
-
 		switch (bc->metrics.os) {
 		case TargetOs_windows:
 			bc->link_flags = str_lit("/machine:x86 ");
@@ -856,10 +849,6 @@ void init_build_context(TargetMetrics *cross_target) {
 			break;
 		}
 	} else if (bc->metrics.arch == TargetArch_arm64) {
-		if (bc->microarch.len == 0) {
-			llc_flags = gb_string_appendc(llc_flags, "-march=arm64 ");
-		}
-
 		switch (bc->metrics.os) {
 		case TargetOs_darwin:
 			bc->link_flags = str_lit("-arch arm64 ");
@@ -872,50 +861,9 @@ void init_build_context(TargetMetrics *cross_target) {
 		gb_printf_err("Compiler Error: Unsupported architecture\n");;
 		gb_exit(1);
 	}
-	llc_flags = gb_string_appendc(llc_flags, " ");
-
 
 	bc->optimization_level = gb_clamp(bc->optimization_level, 0, 3);
 
-	gbString opt_flags = gb_string_make_reserve(heap_allocator(), 64);
-
-	if (bc->microarch.len != 0) {
-		opt_flags = gb_string_appendc(opt_flags, "-march=");
-		opt_flags = gb_string_append_length(opt_flags, bc->microarch.text, bc->microarch.len);
-		opt_flags = gb_string_appendc(opt_flags, " ");
-
-		// llc_flags = gb_string_appendc(opt_flags, "-march=");
-		// llc_flags = gb_string_append_length(llc_flags, bc->microarch.text, bc->microarch.len);
-		// llc_flags = gb_string_appendc(llc_flags, " ");
-	}
-
-
-	if (bc->optimization_level != 0) {
-		opt_flags = gb_string_append_fmt(opt_flags, "-O%d ", bc->optimization_level);
-		// NOTE(lachsinc): The following options were previously passed during call
-		// to opt in main.cpp:exec_llvm_opt().
-		//   -die:       Dead instruction elimination
-		//   -memcpyopt: MemCpy optimization
-	}
-	if (bc->ODIN_DEBUG == false) {
-		opt_flags = gb_string_appendc(opt_flags, "-mem2reg -die ");
-	}
-
-
-
-
-
-	// NOTE(lachsinc): This optimization option was previously required to get
-	// around an issue in fmt.odin. Thank bp for tracking it down! Leaving for now until the issue
-	// is resolved and confirmed by Bill. Maybe it should be readded in non-debug builds.
-	// if (bc->ODIN_DEBUG == false) {
-	// 	opt_flags = gb_string_appendc(opt_flags, "-mem2reg ");
-	// }
-
-	bc->opt_flags = make_string_c(opt_flags);
-	bc->llc_flags = make_string_c(llc_flags);
-
-
 	#undef LINK_FLAG_X64
 	#undef LINK_FLAG_386
 }
diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index 00963487f..1acb9732f 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -87,7 +87,7 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 
 	case BuiltinProc_DIRECTIVE: {
 		ast_node(bd, BasicDirective, ce->proc);
-		String name = bd->name;
+		String name = bd->name.string;
 		if (name == "defined") {
 			break;
 		}
@@ -124,7 +124,7 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 
 	case BuiltinProc_DIRECTIVE: {
 		ast_node(bd, BasicDirective, ce->proc);
-		String name = bd->name;
+		String name = bd->name.string;
 		if (name == "location") {
 			if (ce->args.count > 1) {
 				error(ce->args[0], "'#location' expects either 0 or 1 arguments, got %td", ce->args.count);
@@ -1509,6 +1509,10 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 
 			{
 				Type *bt = base_type(x.type);
+				if (are_types_identical(bt, t_f16)) {
+					add_package_dependency(c, "runtime", "min_f16");
+					add_package_dependency(c, "runtime", "max_f16");
+				}
 				if (are_types_identical(bt, t_f32)) {
 					add_package_dependency(c, "runtime", "min_f32");
 					add_package_dependency(c, "runtime", "max_f32");
@@ -2017,11 +2021,92 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 				}
 			}
 
+			operand->mode = Addressing_OptionalOk;
+			operand->type = default_type(x.type);
+		}
+		break;
+
+	case BuiltinProc_sqrt:
+		{
+			Operand x = {};
+			check_expr(c, &x, ce->args[0]);
+			if (x.mode == Addressing_Invalid) {
+				return false;
+			}
+			if (!is_type_float(x.type)) {
+				gbString xts = type_to_string(x.type);
+				error(x.expr, "Expected a floating point value for '%.*s', got %s", LIT(builtin_procs[id].name), xts);
+				gb_string_free(xts);
+				return false;
+			}
+
+			if (x.mode == Addressing_Constant) {
+				f64 v = exact_value_to_f64(x.value);
+
+				operand->mode = Addressing_Constant;
+				operand->type = x.type;
+				operand->value = exact_value_float(gb_sqrt(v));
+				break;
+			}
 			operand->mode = Addressing_Value;
-			operand->type = make_optional_ok_type(default_type(x.type), false); // Just reusing this procedure, it's not optional
+			operand->type = default_type(x.type);
 		}
 		break;
 
+	case BuiltinProc_mem_copy:
+	case BuiltinProc_mem_copy_non_overlapping:
+		{
+			operand->mode = Addressing_NoValue;
+			operand->type = t_invalid;
+
+			Operand dst = {};
+			Operand src = {};
+			Operand len = {};
+			check_expr(c, &dst, ce->args[0]);
+			check_expr(c, &src, ce->args[1]);
+			check_expr(c, &len, ce->args[2]);
+			if (dst.mode == Addressing_Invalid) {
+				return false;
+			}
+			if (src.mode == Addressing_Invalid) {
+				return false;
+			}
+			if (len.mode == Addressing_Invalid) {
+				return false;
+			}
+
+
+			if (!is_type_pointer(dst.type)) {
+				gbString str = type_to_string(dst.type);
+				error(dst.expr, "Expected a pointer value for '%.*s', got %s", LIT(builtin_procs[id].name), str);
+				gb_string_free(str);
+				return false;
+			}
+			if (!is_type_pointer(src.type)) {
+				gbString str = type_to_string(src.type);
+				error(src.expr, "Expected a pointer value for '%.*s', got %s", LIT(builtin_procs[id].name), str);
+				gb_string_free(str);
+				return false;
+			}
+			if (!is_type_integer(len.type)) {
+				gbString str = type_to_string(len.type);
+				error(len.expr, "Expected an integer value for the number of bytes for '%.*s', got %s", LIT(builtin_procs[id].name), str);
+				gb_string_free(str);
+				return false;
+			}
+
+			if (len.mode == Addressing_Constant) {
+				i64 n = exact_value_to_i64(len.value);
+				if (n < 0) {
+					gbString str = expr_to_string(len.expr);
+					error(len.expr, "Expected a non-negative integer value for the number of bytes for '%.*s', got %s", LIT(builtin_procs[id].name), str);
+					gb_string_free(str);
+				}
+			}
+		}
+		break;
+
+
 	case BuiltinProc_atomic_fence:
 	case BuiltinProc_atomic_fence_acq:
 	case BuiltinProc_atomic_fence_rel:
@@ -2149,8 +2234,8 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 			check_assignment(c, &x, elem, builtin_name);
 			check_assignment(c, &y, elem, builtin_name);
 
-			operand->mode = Addressing_Value;
-			operand->type = make_optional_ok_type(elem, /*typed*/false);
+			operand->mode = Addressing_OptionalOk;
+			operand->type = elem;
 			break;
 		}
 		break;
@@ -2425,6 +2510,46 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		}
 		break;
 
+	case BuiltinProc_type_is_variant_of:
+		{
+			if (operand->mode != Addressing_Type) {
+				error(operand->expr, "Expected a type for '%.*s'", LIT(builtin_name));
+				operand->mode = Addressing_Invalid;
+				operand->type = t_invalid;
+				return false;
+			}
+
+
+			Type *u = operand->type;
+
+			if (!is_type_union(u)) {
+				error(operand->expr, "Expected a union type for '%.*s'", LIT(builtin_name));
+				operand->mode = Addressing_Invalid;
+				operand->type = t_invalid;
+				return false;
+			}
+
+			Type *v = check_type(c, ce->args[1]);
+
+			u = base_type(u);
+			GB_ASSERT(u->kind == Type_Union);
+
+			bool is_variant = false;
+
+			for_array(i, u->Union.variants) {
+				Type *vt = u->Union.variants[i];
+				if (are_types_identical(v, vt)) {
+					is_variant = true;
+					break;
+				}
+			}
+
+			operand->mode = Addressing_Constant;
+			operand->type = t_untyped_bool;
+			operand->value = exact_value_bool(is_variant);
+		}
+		break;
+
 	case BuiltinProc_type_struct_field_count:
 		operand->value = exact_value_i64(0);
 		if (operand->mode != Addressing_Type) {
diff --git a/src/check_decl.cpp b/src/check_decl.cpp
index f008317ad..0aef40546 100644
--- a/src/check_decl.cpp
+++ b/src/check_decl.cpp
@@ -289,17 +289,6 @@ void check_type_decl(CheckerContext *ctx, Entity *e, Ast *init_expr, Type *def)
 	if (decl != nullptr) {
 		AttributeContext ac = {};
 		check_decl_attributes(ctx, decl->attributes, type_decl_attribute, &ac);
-		if (ac.atom_op_table != nullptr) {
-			Type *bt = base_type(e->type);
-			switch (bt->kind) {
-			case Type_Struct:
-				bt->Struct.atom_op_table = ac.atom_op_table;
-				break;
-			default:
-				error(e->token, "Only struct types can have custom atom operations");
-				break;
-			}
-		}
 	}
 
 
@@ -352,16 +341,17 @@ void override_entity_in_scope(Entity *original_entity, Entity *new_entity) {
 
 	string_map_set(&found_scope->elements, original_name, new_entity);
 
+	original_entity->flags |= EntityFlag_Overridden;
 	original_entity->type = new_entity->type;
+	original_entity->aliased_of = new_entity;
 
 	if (original_entity->identifier == nullptr) {
 		original_entity->identifier = new_entity->identifier;
 	}
 	if (original_entity->identifier != nullptr &&
 	    original_entity->identifier->kind == Ast_Ident) {
-		original_entity->identifier->Ident.entity = nullptr;
+		original_entity->identifier->Ident.entity = new_entity;
 	}
-	original_entity->flags |= EntityFlag_Overridden;
 
 	// IMPORTANT NOTE(bill, 2021-04-10): copy only the variants
 	// This is most likely NEVER required, but it does not at all hurt to keep
@@ -375,6 +365,7 @@ void override_entity_in_scope(Entity *original_entity, Entity *new_entity) {
 void check_const_decl(CheckerContext *ctx, Entity *e, Ast *type_expr, Ast *init, Type *named_type) {
 	GB_ASSERT(e->type == nullptr);
 	GB_ASSERT(e->kind == Entity_Constant);
+	init = unparen_expr(init);
 
 	if (e->flags & EntityFlag_Visited) {
 		e->type = t_invalid;
@@ -408,6 +399,18 @@ void check_const_decl(CheckerContext *ctx, Entity *e, Ast *type_expr, Ast *init,
 			e->kind = Entity_TypeName;
 			e->type = nullptr;
 
+			if (entity != nullptr && entity->type != nullptr &&
+			    is_type_polymorphic_record_unspecialized(entity->type)) {
+				DeclInfo *decl = decl_info_of_entity(e);
+				if (decl != nullptr) {
+					if (decl->attributes.count > 0) {
+						error(decl->attributes[0], "Constant alias declarations cannot have attributes");
+					}
+				}
+
+				override_entity_in_scope(e, entity);
+				return;
+			}
 			check_type_decl(ctx, e, ctx->decl->init_expr, named_type);
 			return;
 		}
@@ -896,10 +899,9 @@ void check_global_variable_decl(CheckerContext *ctx, Entity *&e, Ast *type_expr,
 
 	e->Variable.thread_local_model = ac.thread_local_model;
 	e->Variable.is_export = ac.is_export;
+	e->flags &= ~EntityFlag_Static;
 	if (ac.is_static) {
-		e->flags |= EntityFlag_Static;
-	} else {
-		e->flags &= ~EntityFlag_Static;
+		error(e->token, "@(static) is not supported for global variables, nor required");
 	}
 	ac.link_name = handle_link_name(ctx, e->token, ac.link_name, ac.link_prefix);
 
diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 6c4a78e53..81fe3baa9 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -621,7 +621,9 @@ i64 check_distance_between_types(CheckerContext *c, Operand *operand, Type *type
 		}
 		PolyProcData poly_proc_data = {};
 		if (check_polymorphic_procedure_assignment(c, operand, type, operand->expr, &poly_proc_data)) {
-			add_entity_use(c, operand->expr, poly_proc_data.gen_entity);
+			Entity *e = poly_proc_data.gen_entity;
+			add_type_and_value(c->info, operand->expr, Addressing_Value, e->type, {});
+			add_entity_use(c, operand->expr, e);
 			return 4;
 		}
 	}
@@ -1113,6 +1115,7 @@ bool check_cycle(CheckerContext *c, Entity *curr, bool report) {
 					error(curr->token, "\t%.*s refers to", LIT(curr->token.string));
 				}
 				error(curr->token, "\t%.*s", LIT(curr->token.string));
+				curr->type = t_invalid;
 			}
 			return true;
 		}
@@ -1130,7 +1133,7 @@ Entity *check_ident(CheckerContext *c, Operand *o, Ast *n, Type *named_type, Typ
 	Entity *e = scope_lookup(c->scope, name);
 	if (e == nullptr) {
 		if (is_blank_ident(name)) {
-			error(n, "'_' cannot be used as a value type");
+			error(n, "'_' cannot be used as a value");
 		} else {
 			error(n, "Undeclared name: %.*s", LIT(name));
 		}
@@ -1141,6 +1144,9 @@ Entity *check_ident(CheckerContext *c, Operand *o, Ast *n, Type *named_type, Typ
 		}
 		return nullptr;
 	}
+
+	GB_ASSERT((e->flags & EntityFlag_Overridden) == 0);
+
 	if (e->parent_proc_decl != nullptr &&
 	    e->parent_proc_decl != c->curr_proc_decl) {
 		if (e->kind == Entity_Variable) {
@@ -1195,8 +1201,6 @@ Entity *check_ident(CheckerContext *c, Operand *o, Ast *n, Type *named_type, Typ
 	if (e->state == EntityState_Unresolved) {
 		check_entity_decl(c, e, nullptr, named_type);
 	}
-
-
 	if (e->type == nullptr) {
 		// TODO(bill): Which is correct? return or compiler_error?
 		// compiler_error("How did this happen? type: %s; identifier: %.*s\n", type_to_string(e->type), LIT(name));
@@ -2212,6 +2216,10 @@ void check_shift(CheckerContext *c, Operand *x, Operand *y, Ast *node, Type *typ
 		return;
 	}
 
+	if (is_type_untyped(y->type)) {
+		convert_to_typed(c, y, t_uint);
+	}
+
 	x->mode = Addressing_Value;
 }
 
@@ -2379,9 +2387,15 @@ bool check_cast_internal(CheckerContext *c, Operand *x, Type *type) {
 		if (core_type(bt)->kind == Type_Basic) {
 			if (check_representable_as_constant(c, x->value, bt, &x->value)) {
 				return true;
-			} else if (is_type_pointer(type) && check_is_castable_to(c, x, type)) {
-				return true;
+			} else if (check_is_castable_to(c, x, type)) {
+				if (is_type_pointer(type)) {
+					return true;
+				}
 			}
+		} else if (check_is_castable_to(c, x, type)) {
+			x->value = {};
+			x->mode = Addressing_Value;
+			return true;
 		}
 	} else if (check_is_castable_to(c, x, type)) {
 		if (x->mode != Addressing_Constant) {
@@ -2391,6 +2405,9 @@ bool check_cast_internal(CheckerContext *c, Operand *x, Type *type) {
 		} else if (is_type_union(type)) {
 			x->mode = Addressing_Value;
 		}
+		if (x->mode == Addressing_Value) {
+			x->value = {};
+		}
 		return true;
 	}
 	return false;
@@ -2503,6 +2520,10 @@ bool check_binary_array_expr(CheckerContext *c, Token op, Operand *x, Operand *y
 	return false;
 }
 
+bool is_ise_expr(Ast *node) {
+	node = unparen_expr(node);
+	return node->kind == Ast_ImplicitSelectorExpr;
+}
 
 void check_binary_expr(CheckerContext *c, Operand *x, Ast *node, Type *type_hint, bool use_lhs_as_type_hint=false) {
 	GB_ASSERT(node->kind == Ast_BinaryExpr);
@@ -2520,8 +2541,14 @@ void check_binary_expr(CheckerContext *c, Operand *x, Ast *node, Type *type_hint
 	case Token_CmpEq:
 	case Token_NotEq: {
 		// NOTE(bill): Allow comparisons between types
-		check_expr_or_type(c, x, be->left, type_hint);
-		check_expr_or_type(c, y, be->right, x->type);
+		if (is_ise_expr(be->left)) {
+			// Evalute the right before the left for an '.X' expression
+			check_expr_or_type(c, y, be->right, type_hint);
+			check_expr_or_type(c, x, be->left, y->type);
+		} else {
+			check_expr_or_type(c, x, be->left, type_hint);
+			check_expr_or_type(c, y, be->right, x->type);
+		}
 		bool xt = x->mode == Addressing_Type;
 		bool yt = y->mode == Addressing_Type;
 		// If only one is a type, this is an error
@@ -2628,11 +2655,22 @@ void check_binary_expr(CheckerContext *c, Operand *x, Ast *node, Type *type_hint
 		return;
 
 	default:
-		check_expr_with_type_hint(c, x, be->left, type_hint);
-		if (use_lhs_as_type_hint) {
-			check_expr_with_type_hint(c, y, be->right, x->type);
+		if (is_ise_expr(be->left)) {
+			// Evalute the right before the left for an '.X' expression
+			check_expr_or_type(c, y, be->right, type_hint);
+
+			if (use_lhs_as_type_hint) { // RHS in this case
+				check_expr_or_type(c, x, be->left, y->type);
+			} else {
+				check_expr_with_type_hint(c, x, be->left, type_hint);
+			}
 		} else {
-			check_expr_with_type_hint(c, y, be->right, type_hint);
+			check_expr_with_type_hint(c, x, be->left, type_hint);
+			if (use_lhs_as_type_hint) {
+				check_expr_with_type_hint(c, y, be->right, x->type);
+			} else {
+				check_expr_with_type_hint(c, y, be->right, type_hint);
+			}
 		}
 		break;
 	}
@@ -2852,13 +2890,33 @@ void update_expr_type(CheckerContext *c, Ast *e, Type *type, bool final) {
 		if (token_is_comparison(be->op.kind)) {
 			// NOTE(bill): Do nothing as the types are fine
 		} else if (token_is_shift(be->op.kind)) {
-			update_expr_type(c, be->left,  type, final);
+			update_expr_type(c, be->left, type, final);
 		} else {
 			update_expr_type(c, be->left,  type, final);
 			update_expr_type(c, be->right, type, final);
 		}
 	case_end;
 
+	case_ast_node(te, TernaryIfExpr, e);
+		if (old.value.kind != ExactValue_Invalid) {
+			// See above note in UnaryExpr case
+			break;
+		}
+
+		update_expr_type(c, te->x, type, final);
+		update_expr_type(c, te->y, type, final);
+	case_end;
+
+	case_ast_node(te, TernaryWhenExpr, e);
+		if (old.value.kind != ExactValue_Invalid) {
+			// See above note in UnaryExpr case
+			break;
+		}
+
+		update_expr_type(c, te->x, type, final);
+		update_expr_type(c, te->y, type, final);
+	case_end;
+
 	case_ast_node(pe, ParenExpr, e);
 		update_expr_type(c, pe->expr, type, final);
 	case_end;
@@ -3146,8 +3204,8 @@ void convert_to_typed(CheckerContext *c, Operand *operand, Type *target_type) {
 		break;
 	}
 
-	operand->type = target_type;
 	update_expr_type(c, operand->expr, target_type, true);
+	operand->type = target_type;
 }
 
 bool check_index_value(CheckerContext *c, bool open_range, Ast *index_value, i64 max_count, i64 *value, Type *type_hint=nullptr) {
@@ -3896,6 +3954,16 @@ bool check_assignment_arguments(CheckerContext *ctx, Array<Operand> const &lhs,
 					add_type_and_value(&c->checker->info, o.expr, o.mode, tuple, o.value);
 				}
 
+				if (o.mode == Addressing_OptionalOk && expr->kind == Ast_TypeAssertion) {
+					// NOTE(bill): Used only for optimizations in the backend
+					if (is_blank_ident(lhs[0].expr)) {
+						expr->TypeAssertion.ignores[0] = true;
+					}
+					if (is_blank_ident(lhs[1].expr)) {
+						expr->TypeAssertion.ignores[1] = true;
+					}
+				}
+
 				array_add(operands, val0);
 				array_add(operands, val1);
 				optional_ok = true;
@@ -4010,6 +4078,16 @@ bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize lhs_count,
 					add_type_and_value(&c->checker->info, o.expr, o.mode, tuple, o.value);
 				}
 
+				if (o.mode == Addressing_OptionalOk && expr->kind == Ast_TypeAssertion) {
+					// NOTE(bill): Used only for optimizations in the backend
+					if (is_blank_ident(lhs[0]->token)) {
+						expr->TypeAssertion.ignores[0] = true;
+					}
+					if (is_blank_ident(lhs[1]->token)) {
+						expr->TypeAssertion.ignores[1] = true;
+					}
+				}
+
 				array_add(operands, val0);
 				array_add(operands, val1);
 				optional_ok = true;
@@ -4034,6 +4112,16 @@ bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize lhs_count,
 }
 
 
+bool is_expr_constant_zero(Ast *expr) {
+	GB_ASSERT(expr != nullptr);
+	auto v = exact_value_to_integer(expr->tav.value);
+	if (v.kind == ExactValue_Integer) {
+		return big_int_cmp_zero(&v.value_integer) == 0;
+	}
+	return false;
+}
+
+
 CALL_ARGUMENT_CHECKER(check_call_arguments_internal) {
 	ast_node(ce, CallExpr, call);
 	GB_ASSERT(is_type_proc(proc_type));
@@ -4203,8 +4291,13 @@ CALL_ARGUMENT_CHECKER(check_call_arguments_internal) {
 						if (show_error) {
 							check_assignment(c, &o, t, str_lit("argument"));
 						}
-						err = CallArgumentError_WrongTypes;
+						// TODO(bill, 2021-05-05): Is this incorrect logic to only fail if there is ambiguity for definite?
+						if (o.mode == Addressing_Invalid) {
+							err = CallArgumentError_WrongTypes;
+						}
 					}
+				} else if (show_error) {
+					check_assignment(c, &o, t, str_lit("argument"));
 				}
 				score += s;
 
@@ -4220,7 +4313,10 @@ CALL_ARGUMENT_CHECKER(check_call_arguments_internal) {
 				if (o.mode == Addressing_Type && is_type_typeid(e->type)) {
 					add_type_info_type(c, o.type);
 					add_type_and_value(c->info, o.expr, Addressing_Value, e->type, exact_value_typeid(o.type));
+				} else if (show_error && is_type_untyped(o.type)) {
+					update_expr_type(c, o.expr, t, true);
 				}
+
 			}
 
 			if (variadic) {
@@ -4258,6 +4354,8 @@ CALL_ARGUMENT_CHECKER(check_call_arguments_internal) {
 							check_assignment(c, &o, t, str_lit("argument"));
 						}
 						err = CallArgumentError_WrongTypes;
+					} else if (show_error) {
+						check_assignment(c, &o, t, str_lit("argument"));
 					}
 					score += s;
 					if (is_type_any(elem)) {
@@ -4266,6 +4364,8 @@ CALL_ARGUMENT_CHECKER(check_call_arguments_internal) {
 					if (o.mode == Addressing_Type && is_type_typeid(t)) {
 						add_type_info_type(c, o.type);
 						add_type_and_value(c->info, o.expr, Addressing_Value, t, exact_value_typeid(o.type));
+					} else if (show_error && is_type_untyped(o.type)) {
+						update_expr_type(c, o.expr, t, true);
 					}
 				}
 			}
@@ -4480,6 +4580,8 @@ CALL_ARGUMENT_CHECKER(check_named_call_arguments) {
 						err = CallArgumentError_NoneConstantParameter;
 					}
 				}
+			} else if (show_error) {
+				check_assignment(c, o, e->type, str_lit("procedure argument"));
 			}
 			score += s;
 		}
@@ -5414,7 +5516,7 @@ ExprKind check_call_expr(CheckerContext *c, Operand *operand, Ast *call, Ast *pr
 	if (proc != nullptr &&
 	    proc->kind == Ast_BasicDirective) {
 		ast_node(bd, BasicDirective, proc);
-		String name = bd->name;
+		String name = bd->name.string;
 		if (name == "location" || name == "assert" || name == "panic" || name == "defined" || name == "config" || name == "load") {
 			operand->mode = Addressing_Builtin;
 			operand->builtin_id = BuiltinProc_DIRECTIVE;
@@ -5475,6 +5577,15 @@ ExprKind check_call_expr(CheckerContext *c, Operand *operand, Ast *call, Ast *pr
 	if (operand->mode == Addressing_Type) {
 		Type *t = operand->type;
 		if (is_type_polymorphic_record(t)) {
+			if (!is_type_named(t)) {
+				gbString s = expr_to_string(operand->expr);
+				error(call, "Illegal use of an unnamed polymorphic record, %s", s);
+				gb_string_free(s);
+				operand->mode = Addressing_Invalid;
+				operand->type = t_invalid;;
+				return Expr_Expr;
+			}
+
 			auto err = check_polymorphic_record_type(c, operand, call);
 			if (err == 0) {
 				Ast *ident = operand->expr;
@@ -5509,9 +5620,15 @@ ExprKind check_call_expr(CheckerContext *c, Operand *operand, Ast *call, Ast *pr
 				}
 				check_expr(c, operand, arg);
 				if (operand->mode != Addressing_Invalid) {
-					check_cast(c, operand, t);
+					if (is_type_polymorphic(t)) {
+						error(call, "A polymorphic type cannot be used in a type conversion");
+					} else {
+						// NOTE(bill): Otherwise the compiler can override the polymorphic type
+						// as it assumes it is determining the type
+						check_cast(c, operand, t);
+					}
 				}
-
+				operand->type = t;
 				break;
 			}
 			}
@@ -5661,7 +5778,7 @@ void check_expr_with_type_hint(CheckerContext *c, Operand *o, Ast *e, Type *t) {
 		break;
 	case Addressing_Type:
 		if (t == nullptr || !is_type_typeid(t)) {
-			err_str = "is not an expression but a type";
+			err_str = "is not an expression but a type, in this context it is ambiguous";
 		}
 		break;
 	case Addressing_Builtin:
@@ -5849,8 +5966,9 @@ bool check_range(CheckerContext *c, Ast *node, Operand *x, Operand *y, ExactValu
 
 		TokenKind op = Token_Lt;
 		switch (ie->op.kind) {
-		case Token_Ellipsis:  op = Token_LtEq; break;
-		case Token_RangeHalf: op = Token_Lt; break;
+		case Token_Ellipsis:  op = Token_LtEq; break; // ..
+		case Token_RangeFull: op = Token_LtEq; break; // ..=
+		case Token_RangeHalf: op = Token_Lt;   break; // ..<
 		default: error(ie->op, "Invalid range operator"); break;
 		}
 		bool ok = compare_exact_values(op, a, b);
@@ -5861,7 +5979,7 @@ bool check_range(CheckerContext *c, Ast *node, Operand *x, Operand *y, ExactValu
 		}
 
 		ExactValue inline_for_depth = exact_value_sub(b, a);
-		if (ie->op.kind == Token_Ellipsis) {
+		if (ie->op.kind != Token_RangeHalf) {
 			inline_for_depth = exact_value_increment_one(inline_for_depth);
 		}
 
@@ -5896,6 +6014,88 @@ bool check_is_operand_compound_lit_constant(CheckerContext *c, Operand *o) {
 }
 
 
+bool attempt_implicit_selector_expr(CheckerContext *c, Operand *o, AstImplicitSelectorExpr *ise, Type *th) {
+	if (is_type_enum(th)) {
+		Type *enum_type = base_type(th);
+		GB_ASSERT(enum_type->kind == Type_Enum);
+
+		String name = ise->selector->Ident.token.string;
+
+		Entity *e = scope_lookup_current(enum_type->Enum.scope, name);
+		if (e == nullptr) {
+			return false;
+		}
+		GB_ASSERT(are_types_identical(base_type(e->type), enum_type));
+		GB_ASSERT(e->kind == Entity_Constant);
+		o->value = e->Constant.value;
+		o->mode = Addressing_Constant;
+		o->type = e->type;
+		return true;
+	}
+	bool show_error = true;
+	if (is_type_union(th)) {
+		Type *union_type = base_type(th);
+		isize enum_count = 0;
+		Type *et = nullptr;
+
+		auto operands = array_make<Operand>(temporary_allocator(), 0, union_type->Union.variants.count);
+
+		for_array(i, union_type->Union.variants) {
+			Type *vt = union_type->Union.variants[i];
+
+			Operand x = {};
+			if (attempt_implicit_selector_expr(c, &x, ise, vt)) {
+				array_add(&operands, x);
+			}
+		}
+
+		if (operands.count == 1) {
+			*o = operands[0];
+			return true;
+		}
+	}
+	return false;
+}
+
+ExprKind check_implicit_selector_expr(CheckerContext *c, Operand *o, Ast *node, Type *type_hint) {
+	ast_node(ise, ImplicitSelectorExpr, node);
+
+	o->type = t_invalid;
+	o->expr = node;
+	o->mode = Addressing_Invalid;
+
+	Type *th = type_hint;
+
+	if (th == nullptr) {
+		gbString str = expr_to_string(node);
+		error(node, "Cannot determine type for implicit selector expression '%s'", str);
+		gb_string_free(str);
+		return Expr_Expr;
+	}
+	o->type = th;
+	Type *enum_type = th;
+
+	bool ok = attempt_implicit_selector_expr(c, o, ise, th);
+	if (!ok) {
+		String name = ise->selector->Ident.token.string;
+
+		if (is_type_enum(th)) {
+			gbString typ = type_to_string(th);
+			error(node, "Undeclared name %.*s for type '%s'", LIT(name), typ);
+			gb_string_free(typ);
+		} else {
+			gbString typ = type_to_string(th);
+			gbString str = expr_to_string(node);
+			error(node, "Invalid type '%s' for implicit selector expression '%s'", typ, str);
+			gb_string_free(str);
+			gb_string_free(typ);
+		}
+	}
+
+	o->expr = node;
+	return Expr_Expr;
+}
+
 ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type *type_hint) {
 	u32 prev_state_flags = c->state_flags;
 	defer (c->state_flags = prev_state_flags);
@@ -5991,13 +6191,14 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 
 	case_ast_node(bd, BasicDirective, node);
 		o->mode = Addressing_Constant;
-		if (bd->name == "file") {
+		String name = bd->name.string;
+		if (name == "file") {
 			o->type = t_untyped_string;
 			o->value = exact_value_string(get_file_path_string(bd->token.pos.file_id));
-		} else if (bd->name == "line") {
+		} else if (name == "line") {
 			o->type = t_untyped_integer;
 			o->value = exact_value_i64(bd->token.pos.line);
-		} else if (bd->name == "procedure") {
+		} else if (name == "procedure") {
 			if (c->curr_proc_decl == nullptr) {
 				error(node, "#procedure may only be used within procedures");
 				o->type = t_untyped_string;
@@ -6006,7 +6207,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 				o->type = t_untyped_string;
 				o->value = exact_value_string(c->proc_name);
 			}
-		} else if (bd->name == "caller_location") {
+		} else if (name == "caller_location") {
 			init_core_source_code_location(c->checker);
 			error(node, "#caller_location may only be used as a default argument parameter");
 			o->type = t_source_code_location;
@@ -6061,88 +6262,6 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 		o->type = type;
 	case_end;
 
-	case_ast_node(te, TernaryExpr, node);
-		Operand cond = {Addressing_Invalid};
-		check_expr(c, &cond, te->cond);
-		node->viral_state_flags |= te->cond->viral_state_flags;
-
-		if (cond.mode != Addressing_Invalid && !is_type_boolean(cond.type)) {
-			error(te->cond, "Non-boolean condition in if expression");
-		}
-
-		Operand x = {Addressing_Invalid};
-		Operand y = {Addressing_Invalid};
-		check_expr_or_type(c, &x, te->x, type_hint);
-		node->viral_state_flags |= te->x->viral_state_flags;
-
-		if (te->y != nullptr) {
-			check_expr_or_type(c, &y, te->y, type_hint);
-			node->viral_state_flags |= te->y->viral_state_flags;
-		} else {
-			error(node, "A ternary expression must have an else clause");
-			return kind;
-		}
-
-		if (x.type == nullptr || x.type == t_invalid ||
-		    y.type == nullptr || y.type == t_invalid) {
-			return kind;
-		}
-
-		if (x.mode == Addressing_Type && y.mode == Addressing_Type &&
-		    cond.mode == Addressing_Constant && is_type_boolean(cond.type)) {
-			o->mode = Addressing_Type;
-			if (cond.value.value_bool) {
-				o->type = x.type;
-				o->expr = x.expr;
-			} else {
-				o->type = y.type;
-				o->expr = y.expr;
-			}
-			return Expr_Expr;
-		}
-
-		convert_to_typed(c, &x, y.type);
-		if (x.mode == Addressing_Invalid) {
-			return kind;
-		}
-		convert_to_typed(c, &y, x.type);
-		if (y.mode == Addressing_Invalid) {
-			x.mode = Addressing_Invalid;
-			return kind;
-		}
-
-		if (!ternary_compare_types(x.type, y.type)) {
-			gbString its = type_to_string(x.type);
-			gbString ets = type_to_string(y.type);
-			error(node, "Mismatched types in ternary expression, %s vs %s", its, ets);
-			gb_string_free(ets);
-			gb_string_free(its);
-			return kind;
-		}
-
-		Type *type = x.type;
-		if (is_type_untyped_nil(type) || is_type_untyped_undef(type)) {
-			type = y.type;
-		}
-
-		o->type = type;
-		o->mode = Addressing_Value;
-
-		if (cond.mode == Addressing_Constant && is_type_boolean(cond.type) &&
-		    x.mode == Addressing_Constant &&
-		    y.mode == Addressing_Constant) {
-
-			o->mode = Addressing_Constant;
-
-			if (cond.value.value_bool) {
-				o->value = x.value;
-			} else {
-				o->value = y.value;
-			}
-		}
-
-	case_end;
-
 	case_ast_node(te, TernaryIfExpr, node);
 		Operand cond = {Addressing_Invalid};
 		check_expr(c, &cond, te->cond);
@@ -6255,7 +6374,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 					if (cl->type->ArrayType.tag != nullptr) {
 						Ast *tag = cl->type->ArrayType.tag;
 						GB_ASSERT(tag->kind == Ast_BasicDirective);
-						String name = tag->BasicDirective.name;
+						String name = tag->BasicDirective.name.string;
 						if (name == "soa") {
 							error(node, "#soa arrays are not supported for compound literals");
 							return kind;
@@ -6267,7 +6386,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 				if (cl->elems.count > 0) {
 					Ast *tag = cl->type->DynamicArrayType.tag;
 					GB_ASSERT(tag->kind == Ast_BasicDirective);
-					String name = tag->BasicDirective.name;
+					String name = tag->BasicDirective.name.string;
 					if (name == "soa") {
 						error(node, "#soa arrays are not supported for compound literals");
 						return kind;
@@ -7279,10 +7398,11 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 	case_end;
 
 	case_ast_node(ue, UnaryExpr, node);
-		Ast *prev_unary_address_hint = c->unary_address_hint;
-		c->unary_address_hint = unparen_expr(node);
-		check_expr_base(c, o, ue->expr, type_hint);
-		c->unary_address_hint = prev_unary_address_hint;
+		Type *th = type_hint;
+		if (ue->op.kind == Token_And) {
+			th = type_deref(th);
+		}
+		check_expr_base(c, o, ue->expr, th);
 		node->viral_state_flags |= ue->expr->viral_state_flags;
 
 		if (o->mode == Addressing_Invalid) {
@@ -7444,68 +7564,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 
 
 	case_ast_node(ise, ImplicitSelectorExpr, node);
-		o->type = t_invalid;
-		o->expr = node;
-		o->mode = Addressing_Invalid;
-
-		Type *th = type_hint;
-
-		if (th == nullptr) {
-			gbString str = expr_to_string(node);
-			error(node, "Cannot determine type for implicit selector expression '%s'", str);
-			gb_string_free(str);
-			return Expr_Expr;
-		}
-		o->type = th;
-		Type *enum_type = th;
-
-		if (!is_type_enum(th)) {
-			bool show_error = true;
-			if (is_type_union(th)) {
-				Type *union_type = base_type(th);
-				isize enum_count = 0;
-				Type *et = nullptr;
-				for_array(i, union_type->Union.variants) {
-					Type *vt = union_type->Union.variants[i];
-					if (is_type_enum(vt)) {
-						enum_count += 1;
-						et = vt;
-					}
-				}
-				if (enum_count == 1) {
-					show_error = false;
-					enum_type = et;
-				}
-			}
-
-			if (show_error) {
-				gbString typ = type_to_string(th);
-				gbString str = expr_to_string(node);
-				error(node, "Invalid type '%s' for implicit selector expression '%s'", typ, str);
-				gb_string_free(str);
-				gb_string_free(typ);
-				return Expr_Expr;
-			}
-		}
-		GB_ASSERT(ise->selector->kind == Ast_Ident);
-		String name = ise->selector->Ident.token.string;
-
-		enum_type = base_type(enum_type);
-		GB_ASSERT(enum_type->kind == Type_Enum);
-		Entity *e = scope_lookup_current(enum_type->Enum.scope, name);
-		if (e == nullptr) {
-			gbString typ = type_to_string(th);
-			error(node, "Undeclared name %.*s for type '%s'", LIT(name), typ);
-			gb_string_free(typ);
-			return Expr_Expr;
-		}
-		GB_ASSERT(are_types_identical(base_type(e->type), enum_type));
-		GB_ASSERT(e->kind == Entity_Constant);
-		o->value = e->Constant.value;
-		o->mode = Addressing_Constant;
-		o->type = e->type;
-
-		return Expr_Expr;
+		return check_implicit_selector_expr(c, o, node, type_hint);
 	case_end;
 
 	case_ast_node(ie, IndexExpr, node);
@@ -7542,47 +7601,6 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			return Expr_Expr;
 		}
 
-		if (t->kind == Type_Struct) {
-			TypeAtomOpTable *atom_op_table = t->Struct.atom_op_table;
-			if (atom_op_table != nullptr) {
-				if (atom_op_table->op[TypeAtomOp_index_set]) {
-					if (c->assignment_lhs_hint == node) {
-						o->mode = Addressing_AtomOpAssign;
-						o->type = o->type;
-						o->expr = node;
-						return kind;
-					}
-				}
-				if (atom_op_table->op[TypeAtomOp_index_get]) {
-					Entity *e = atom_op_table->op[TypeAtomOp_index_get];
-					if (ie->index == nullptr) {
-						gbString str = expr_to_string(o->expr);
-						error(o->expr, "Missing index for '%s'", str);
-						gb_string_free(str);
-						o->mode = Addressing_Invalid;
-						o->expr = node;
-						return kind;
-					}
-
-					GB_ASSERT(e->identifier != nullptr);
-					Ast *proc_ident = clone_ast(e->identifier);
-
-					auto args = array_make<Ast *>(heap_allocator(), 2);
-					args[0] = ie->expr;
-					args[1] = ie->index;
-
-					GB_ASSERT(c->file != nullptr);
-					Ast *fake_call = ast_call_expr(c->file, proc_ident, args, ie->open, ie->close, {});
-					check_expr_base(c, o, fake_call, type_hint);
-					AtomOpMapEntry entry = {TypeAtomOp_index_get, fake_call};
-					map_set(&c->info->atom_op_map, hash_pointer(node), entry);
-					o->expr = node;
-					return kind;
-				}
-			}
-		}
-
-
 		i64 max_count = -1;
 		bool valid = check_set_index_data(o, t, is_ptr, &max_count, o->type);
 
@@ -7721,37 +7739,6 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			if (is_type_soa_struct(t)) {
 				valid = true;
 				o->type = make_soa_struct_slice(c, nullptr, nullptr, t->Struct.soa_elem);
-			} else {
-				TypeAtomOpTable *atom_op_table = t->Struct.atom_op_table;
-				if (atom_op_table != nullptr && atom_op_table->op[TypeAtomOp_slice]) {
-					Entity *e = atom_op_table->op[TypeAtomOp_slice];
-					GB_ASSERT(e->identifier != nullptr);
-					Ast *proc_ident = clone_ast(e->identifier);
-
-					Ast *expr = se->expr;
-					if (o->mode == Addressing_Variable) {
-						expr = ast_unary_expr(c->file, {Token_And, STR_LIT("&")}, expr);
-					} else if (is_type_pointer(o->type)) {
-						// Okay
-					} else {
-						gbString str = expr_to_string(node);
-						error(node, "Cannot slice '%s', value is not addressable", str);
-						gb_string_free(str);
-						o->mode = Addressing_Invalid;
-						o->expr = node;
-						return kind;
-					}
-					auto args = array_make<Ast *>(heap_allocator(), 1);
-					args[0] = expr;
-
-
-					GB_ASSERT(c->file != nullptr);
-					Ast *fake_call = ast_call_expr(c->file, proc_ident, args, se->open, se->close, {});
-					check_expr_base(c, o, fake_call, type_hint);
-					AtomOpMapEntry entry = {TypeAtomOp_slice, fake_call};
-					map_set(&c->info->atom_op_map, hash_pointer(node), entry);
-					valid = true;
-				}
 			}
 			break;
 
@@ -7780,10 +7767,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			return kind;
 		}
 
-		o->mode = Addressing_Value;
-
 		if (se->low == nullptr && se->high != nullptr) {
-			// error(se->interval0, "1st index is required if a 2nd index is specified");
 			// It is okay to continue as it will assume the 1st index is zero
 		}
 
@@ -7818,6 +7802,16 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			}
 		}
 
+		if (max_count < 0)  {
+			if (o->mode == Addressing_Constant) {
+				gbString s = expr_to_string(se->expr);
+				error(se->expr, "Cannot slice constant value '%s'", s);
+				gb_string_free(s);
+			}
+		}
+
+		o->mode = Addressing_Value;
+
 		if (is_type_string(t) && max_count >= 0) {
 			bool all_constant = true;
 			for (isize i = 0; i < gb_count_of(nodes); i++) {
@@ -8158,7 +8152,7 @@ gbString write_expr_to_string(gbString str, Ast *node, bool shorthand) {
 
 	case_ast_node(bd, BasicDirective, node);
 		str = gb_string_append_rune(str, '#');
-		str = string_append_string(str, bd->name);
+		str = string_append_string(str, bd->name.string);
 	case_end;
 
 	case_ast_node(ud, Undef, node);
@@ -8222,20 +8216,22 @@ gbString write_expr_to_string(gbString str, Ast *node, bool shorthand) {
 		str = write_expr_to_string(str, be->right, shorthand);
 	case_end;
 
-	case_ast_node(te, TernaryExpr, node);
-		str = write_expr_to_string(str, te->cond, shorthand);
-		str = gb_string_appendc(str, " ? ");
-		str = write_expr_to_string(str, te->x, shorthand);
-		str = gb_string_appendc(str, " : ");
-		str = write_expr_to_string(str, te->y, shorthand);
-	case_end;
-
 	case_ast_node(te, TernaryIfExpr, node);
-		str = write_expr_to_string(str, te->x, shorthand);
-		str = gb_string_appendc(str, " if ");
-		str = write_expr_to_string(str, te->cond, shorthand);
-		str = gb_string_appendc(str, " else ");
-		str = write_expr_to_string(str, te->y, shorthand);
+		TokenPos x = ast_token(te->x).pos;
+		TokenPos cond = ast_token(te->cond).pos;
+		if (x < cond) {
+			str = write_expr_to_string(str, te->x, shorthand);
+			str = gb_string_appendc(str, " if ");
+			str = write_expr_to_string(str, te->cond, shorthand);
+			str = gb_string_appendc(str, " else ");
+			str = write_expr_to_string(str, te->y, shorthand);
+		} else {
+			str = write_expr_to_string(str, te->cond, shorthand);
+			str = gb_string_appendc(str, " ? ");
+			str = write_expr_to_string(str, te->x, shorthand);
+			str = gb_string_appendc(str, " : ");
+			str = write_expr_to_string(str, te->y, shorthand);
+		}
 	case_end;
 
 	case_ast_node(te, TernaryWhenExpr, node);
@@ -8525,8 +8521,18 @@ gbString write_expr_to_string(gbString str, Ast *node, bool shorthand) {
 
 	case_ast_node(st, StructType, node);
 		str = gb_string_appendc(str, "struct ");
+		if (st->polymorphic_params) {
+			str = gb_string_append_rune(str, '(');
+			str = write_expr_to_string(str, st->polymorphic_params, shorthand);
+			str = gb_string_appendc(str, ") ");
+		}
 		if (st->is_packed)    str = gb_string_appendc(str, "#packed ");
 		if (st->is_raw_union) str = gb_string_appendc(str, "#raw_union ");
+		if (st->align) {
+			str = gb_string_appendc(str, "#align ");
+			str = write_expr_to_string(str, st->align, shorthand);
+			str = gb_string_append_rune(str, ' ');
+		}
 		str = gb_string_append_rune(str, '{');
 		if (shorthand) {
 			str = gb_string_appendc(str, "...");
@@ -8539,6 +8545,18 @@ gbString write_expr_to_string(gbString str, Ast *node, bool shorthand) {
 
 	case_ast_node(st, UnionType, node);
 		str = gb_string_appendc(str, "union ");
+		if (st->polymorphic_params) {
+			str = gb_string_append_rune(str, '(');
+			str = write_expr_to_string(str, st->polymorphic_params, shorthand);
+			str = gb_string_appendc(str, ") ");
+		}
+		if (st->no_nil) str = gb_string_appendc(str, "#no_nil ");
+		if (st->maybe)  str = gb_string_appendc(str, "#maybe ");
+		if (st->align) {
+			str = gb_string_appendc(str, "#align ");
+			str = write_expr_to_string(str, st->align, shorthand);
+			str = gb_string_append_rune(str, ' ');
+		}
 		str = gb_string_append_rune(str, '{');
 		if (shorthand) {
 			str = gb_string_appendc(str, "...");
diff --git a/src/check_stmt.cpp b/src/check_stmt.cpp
index a3c9a529c..7772b5c97 100644
--- a/src/check_stmt.cpp
+++ b/src/check_stmt.cpp
@@ -7,7 +7,7 @@ bool is_diverging_stmt(Ast *stmt) {
 		return false;
 	}
 	if (expr->CallExpr.proc->kind == Ast_BasicDirective) {
-		String name = expr->CallExpr.proc->BasicDirective.name;
+		String name = expr->CallExpr.proc->BasicDirective.name.string;
 		return name == "panic";
 	}
 	Ast *proc = unparen_expr(expr->CallExpr.proc);
@@ -939,6 +939,7 @@ void check_switch_stmt(CheckerContext *ctx, Ast *node, u32 mod_flags) {
 				TokenKind upper_op = Token_Invalid;
 				switch (be->op.kind) {
 				case Token_Ellipsis:  upper_op = Token_GtEq; break;
+				case Token_RangeFull: upper_op = Token_GtEq; break;
 				case Token_RangeHalf: upper_op = Token_Gt;   break;
 				default: GB_PANIC("Invalid range operator"); break;
 				}
@@ -960,9 +961,44 @@ void check_switch_stmt(CheckerContext *ctx, Ast *node, u32 mod_flags) {
 				Operand b1 = rhs;
 				check_comparison(ctx, &a1, &b1, Token_LtEq);
 
-				add_constant_switch_case(ctx, &seen, lhs);
-				if (upper_op == Token_GtEq) {
-					add_constant_switch_case(ctx, &seen, rhs);
+				if (is_type_enum(x.type)) {
+					// TODO(bill): Fix this logic so it's fast!!!
+
+					i64 v0 = exact_value_to_i64(lhs.value);
+					i64 v1 = exact_value_to_i64(rhs.value);
+					Operand v = {};
+					v.mode = Addressing_Constant;
+					v.type = x.type;
+					v.expr = x.expr;
+
+					Type *bt = base_type(x.type);
+					GB_ASSERT(bt->kind == Type_Enum);
+					for (i64 vi = v0; vi <= v1; vi++) {
+						if (upper_op != Token_GtEq && vi == v1) {
+							break;
+						}
+
+						bool found = false;
+						for_array(j, bt->Enum.fields) {
+							Entity *f = bt->Enum.fields[j];
+							GB_ASSERT(f->kind == Entity_Constant);
+
+							i64 fv = exact_value_to_i64(f->Constant.value);
+							if (fv == vi) {
+								found = true;
+								break;
+							}
+						}
+						if (found) {
+							v.value = exact_value_i64(vi);
+							add_constant_switch_case(ctx, &seen, v);
+						}
+					}
+				} else {
+					add_constant_switch_case(ctx, &seen, lhs);
+					if (upper_op == Token_GtEq) {
+						add_constant_switch_case(ctx, &seen, rhs);
+					}
 				}
 
 				if (is_type_string(x.type)) {
@@ -1400,6 +1436,28 @@ void check_stmt_internal(CheckerContext *ctx, Ast *node, u32 flags) {
 			gbString expr_str = expr_to_string(operand.expr);
 			error(node, "Expression is not used: '%s'", expr_str);
 			gb_string_free(expr_str);
+			if (operand.expr->kind == Ast_BinaryExpr) {
+				ast_node(be, BinaryExpr, operand.expr);
+				if (be->op.kind != Token_CmpEq) {
+					break;
+				}
+
+				switch (be->left->tav.mode) {
+				case Addressing_Context:
+				case Addressing_Variable:
+				case Addressing_MapIndex:
+				case Addressing_SoaVariable:
+					{
+						gbString lhs = expr_to_string(be->left);
+						gbString rhs = expr_to_string(be->right);
+						error_line("\tSuggestion: Did you mean to do an assignment?\n", lhs, rhs);
+						error_line("\t            '%s = %s;'\n", lhs, rhs);
+						gb_string_free(rhs);
+						gb_string_free(lhs);
+					}
+					break;
+				}
+			}
 
 			break;
 		}
@@ -1454,53 +1512,6 @@ void check_stmt_internal(CheckerContext *ctx, Ast *node, u32 flags) {
 			auto lhs_to_ignore = array_make<bool>(temporary_allocator(), lhs_count);
 
 			isize max = gb_min(lhs_count, rhs_count);
-			// NOTE(bill, 2020-05-02): This is an utter hack to get these custom atom operations working
-			// correctly for assignments
-			for (isize i = 0; i < max; i++) {
-				if (lhs_operands[i].mode == Addressing_AtomOpAssign) {
-					Operand lhs = lhs_operands[i];
-
-					Type *t = base_type(lhs.type);
-					GB_ASSERT(t->kind == Type_Struct);
-					ast_node(ie, IndexExpr, unparen_expr(lhs.expr));
-
-					TypeAtomOpTable *atom_op_table = t->Struct.atom_op_table;
-					GB_ASSERT(atom_op_table->op[TypeAtomOp_index_set] != nullptr);
-					Entity *e = atom_op_table->op[TypeAtomOp_index_set];
-
-					GB_ASSERT(e->identifier != nullptr);
-					Ast *proc_ident = clone_ast(e->identifier);
-					GB_ASSERT(ctx->file != nullptr);
-
-
-					TypeAndValue tv = type_and_value_of_expr(ie->expr);
-					Ast *expr = ie->expr;
-					if (is_type_pointer(tv.type)) {
-						// Okay
-					} else if (tv.mode == Addressing_Variable) {
-						// NOTE(bill): Hack it to take the address instead
-						expr = ast_unary_expr(ctx->file, {Token_And, STR_LIT("&")}, ie->expr);
-					} else {
-						continue;
-					}
-
-					auto args = array_make<Ast *>(heap_allocator(), 3);
-					args[0] = expr;
-					args[1] = ie->index;
-					args[2] = rhs_operands[i].expr;
-
-					Ast *fake_call = ast_call_expr(ctx->file, proc_ident, args, ie->open, ie->close, {});
-					Operand fake_operand = {};
-					fake_operand.expr = lhs.expr;
-					check_expr_base(ctx, &fake_operand, fake_call, nullptr);
-					AtomOpMapEntry entry = {TypeAtomOp_index_set, fake_call};
-					map_set(&ctx->info->atom_op_map, hash_pointer(lhs.expr), entry);
-
-					lhs_to_ignore[i] = true;
-
-				}
-			}
-
 			for (isize i = 0; i < max; i++) {
 				if (lhs_to_ignore[i]) {
 					continue;
@@ -1526,8 +1537,8 @@ void check_stmt_internal(CheckerContext *ctx, Ast *node, u32 flags) {
 			}
 			Operand lhs = {Addressing_Invalid};
 			Operand rhs = {Addressing_Invalid};
-			Ast binary_expr = {Ast_BinaryExpr};
-			ast_node(be, BinaryExpr, &binary_expr);
+			Ast *binary_expr = alloc_ast_node(node->file, Ast_BinaryExpr);
+			ast_node(be, BinaryExpr, binary_expr);
 			be->op = op;
 			be->op.kind = cast(TokenKind)(cast(i32)be->op.kind - (Token_AddEq - Token_Add));
 			 // NOTE(bill): Only use the first one will be used
@@ -1535,7 +1546,7 @@ void check_stmt_internal(CheckerContext *ctx, Ast *node, u32 flags) {
 			be->right = as->rhs[0];
 
 			check_expr(ctx, &lhs, as->lhs[0]);
-			check_binary_expr(ctx, &rhs, &binary_expr, nullptr, true);
+			check_binary_expr(ctx, &rhs, binary_expr, nullptr, true);
 			if (rhs.mode == Addressing_Invalid) {
 				return;
 			}
@@ -1632,7 +1643,11 @@ void check_stmt_internal(CheckerContext *ctx, Ast *node, u32 flags) {
 		} else {
 			for (isize i = 0; i < result_count; i++) {
 				Entity *e = pt->results->Tuple.variables[i];
-				check_assignment(ctx, &operands[i], e->type, str_lit("return statement"));
+				Operand *o = &operands[i];
+				check_assignment(ctx, o, e->type, str_lit("return statement"));
+				if (is_type_untyped(o->type)) {
+					update_expr_type(ctx, o->expr, e->type, true);
+				}
 			}
 		}
 	case_end;
diff --git a/src/check_type.cpp b/src/check_type.cpp
index aef1ddc7a..419904876 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -322,19 +322,6 @@ void add_polymorphic_record_entity(CheckerContext *ctx, Ast *node, Type *named_t
 		array_add(&array, e);
 		map_set(&ctx->checker->info.gen_types, hash_pointer(original_type), array);
 	}
-
-	{
-		Type *dst_bt = base_type(named_type);
-		Type *src_bt = base_type(original_type);
-		if ((dst_bt != nullptr && src_bt != nullptr) &&
-		    (dst_bt->kind == src_bt->kind)){
-			if (dst_bt->kind == Type_Struct) {
-				if (dst_bt->Struct.atom_op_table == nullptr) {
-					dst_bt->Struct.atom_op_table = src_bt->Struct.atom_op_table;
-				}
-			}
-		}
-	}
 }
 
 Type *check_record_polymorphic_params(CheckerContext *ctx, Ast *polymorphic_params,
@@ -944,6 +931,7 @@ void check_bit_set_type(CheckerContext *c, Type *type, Type *named_type, Ast *no
 
 		switch (be->op.kind) {
 		case Token_Ellipsis:
+		case Token_RangeFull:
 			if (upper - lower >= bits) {
 				error(bs->elem, "bit_set range is greater than %lld bits, %lld bits are required", bits, (upper-lower+1));
 			}
@@ -1203,10 +1191,15 @@ ParameterValue handle_parameter_value(CheckerContext *ctx, Type *in_type, Type *
 
 	if (allow_caller_location &&
 	    expr->kind == Ast_BasicDirective &&
-	    expr->BasicDirective.name == "caller_location") {
+	    expr->BasicDirective.name.string == "caller_location") {
 		init_core_source_code_location(ctx->checker);
 		param_value.kind = ParameterValue_Location;
 		o.type = t_source_code_location;
+
+		if (in_type) {
+			check_assignment(ctx, &o, in_type, str_lit("parameter value"));
+		}
+
 	} else {
 		if (in_type) {
 			check_expr_with_type_hint(ctx, &o, expr, in_type);
@@ -1214,6 +1207,11 @@ ParameterValue handle_parameter_value(CheckerContext *ctx, Type *in_type, Type *
 			check_expr(ctx, &o, expr);
 		}
 
+		if (in_type) {
+			check_assignment(ctx, &o, in_type, str_lit("parameter value"));
+		}
+
+
 		if (is_operand_nil(o)) {
 			param_value.kind = ParameterValue_Nil;
 		} else if (o.mode != Addressing_Constant) {
@@ -1221,16 +1219,7 @@ ParameterValue handle_parameter_value(CheckerContext *ctx, Type *in_type, Type *
 				param_value.kind = ParameterValue_Constant;
 				param_value.value = exact_value_procedure(expr);
 			} else {
-				Entity *e = nullptr;
-				// if (o.mode == Addressing_Value && is_type_proc(o.type)) {
-				if (o.mode == Addressing_Value || o.mode == Addressing_Variable) {
-					Operand x = {};
-					if (expr->kind == Ast_Ident) {
-						e = check_ident(ctx, &x, expr, nullptr, nullptr, false);
-					} else if (expr->kind == Ast_SelectorExpr) {
-						e = check_selector(ctx, &x, expr, nullptr);
-					}
-				}
+				Entity *e = entity_from_expr(o.expr);
 
 				if (e != nullptr) {
 					if (e->kind == Entity_Procedure) {
@@ -1253,8 +1242,11 @@ ParameterValue handle_parameter_value(CheckerContext *ctx, Type *in_type, Type *
 				} else if (allow_caller_location && o.mode == Addressing_Context) {
 					param_value.kind = ParameterValue_Value;
 					param_value.ast_value = expr;
+				} else if (o.value.kind != ExactValue_Invalid) {
+					param_value.kind = ParameterValue_Constant;
+					param_value.value = o.value;
 				} else {
-					error(expr, "Default parameter must be a constant");
+					error(expr, "Default parameter must be a constant, %d", o.mode);
 				}
 			}
 		} else {
@@ -1267,12 +1259,14 @@ ParameterValue handle_parameter_value(CheckerContext *ctx, Type *in_type, Type *
 		}
 	}
 
-	if (in_type) {
-		check_assignment(ctx, &o, in_type, str_lit("parameter value"));
+	if (out_type_) {
+		if (in_type != nullptr) {
+			*out_type_ = in_type;
+		} else {
+			*out_type_ = default_type(o.type);
+		}
 	}
 
-	if (out_type_) *out_type_ = default_type(o.type);
-
 	return param_value;
 }
 
@@ -1389,6 +1383,9 @@ Type *check_get_params(CheckerContext *ctx, Scope *scope, Ast *_params, bool *is
 				}
 			}
 		}
+
+
+
 		if (type == nullptr) {
 			error(param, "Invalid parameter type");
 			type = t_invalid;
@@ -1408,6 +1405,21 @@ Type *check_get_params(CheckerContext *ctx, Scope *scope, Ast *_params, bool *is
 			type = t_invalid;
 		}
 
+		if (is_type_polymorphic(type)) {
+			switch (param_value.kind) {
+			case ParameterValue_Invalid:
+			case ParameterValue_Constant:
+			case ParameterValue_Nil:
+				break;
+			case ParameterValue_Location:
+			case ParameterValue_Value:
+				gbString str = type_to_string(type);
+				error(params[i], "A default value for a parameter must not be a polymorphic constant type, got %s", str);
+				gb_string_free(str);
+				break;
+			}
+		}
+
 
 		if (p->flags&FieldFlag_c_vararg) {
 			if (p->type == nullptr ||
@@ -2109,6 +2121,12 @@ void add_map_key_type_dependencies(CheckerContext *ctx, Type *key) {
 				Entity *field = key->Struct.fields[i];
 				add_map_key_type_dependencies(ctx, field->type);
 			}
+		} else if (key->kind == Type_Union) {
+			add_package_dependency(ctx, "runtime", "default_hasher_n");
+			for_array(i, key->Union.variants) {
+				Type *v = key->Union.variants[i];
+				add_map_key_type_dependencies(ctx, v);
+			}
 		} else if (key->kind == Type_EnumeratedArray) {
 			add_package_dependency(ctx, "runtime", "default_hasher_n");
 			add_map_key_type_dependencies(ctx, key->EnumeratedArray.elem);
@@ -2511,16 +2529,6 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 					return true;
 				}
 			}
-
-			// if (ctx->type_level == 0 && entity->state == EntityState_InProgress) {
-			// 	error(entity->token, "Illegal declaration cycle of `%.*s`", LIT(entity->token.string));
-			// 	for_array(j, *ctx->type_path) {
-			// 		Entity *k = (*ctx->type_path)[j];
-			// 		error(k->token, "\t%.*s refers to", LIT(k->token.string));
-			// 	}
-			// 	error(entity->token, "\t%.*s", LIT(entity->token.string));
-			// 	*type = t_invalid;
-			// }
 			return true;
 		}
 
@@ -2703,7 +2711,7 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 				bool is_partial = false;
 				if (at->tag != nullptr) {
 					GB_ASSERT(at->tag->kind == Ast_BasicDirective);
-					String name = at->tag->BasicDirective.name;
+					String name = at->tag->BasicDirective.name.string;
 					if (name == "partial") {
 						is_partial = true;
 					} else {
@@ -2737,7 +2745,7 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 
 			if (at->tag != nullptr) {
 				GB_ASSERT(at->tag->kind == Ast_BasicDirective);
-				String name = at->tag->BasicDirective.name;
+				String name = at->tag->BasicDirective.name.string;
 				if (name == "soa") {
 					*type = make_soa_struct_fixed(ctx, e, at->elem, elem, count, generic_type);
 				} else if (name == "simd") {
@@ -2762,7 +2770,7 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 
 			if (at->tag != nullptr) {
 				GB_ASSERT(at->tag->kind == Ast_BasicDirective);
-				String name = at->tag->BasicDirective.name;
+				String name = at->tag->BasicDirective.name.string;
 				if (name == "soa") {
 					*type = make_soa_struct_slice(ctx, e, at->elem, elem);
 				} else {
@@ -2782,7 +2790,7 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 		Type *elem = check_type(ctx, dat->elem);
 		if (dat->tag != nullptr) {
 			GB_ASSERT(dat->tag->kind == Ast_BasicDirective);
-			String name = dat->tag->BasicDirective.name;
+			String name = dat->tag->BasicDirective.name.string;
 			if (name == "soa") {
 				*type = make_soa_struct_dynamic_array(ctx, e, dat->elem, elem);
 			} else {
@@ -2883,16 +2891,6 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 		}
 	case_end;
 
-	case_ast_node(te, TernaryExpr, e);
-		Operand o = {};
-		check_expr_or_type(ctx, &o, e);
-		if (o.mode == Addressing_Type) {
-			*type = o.type;
-			set_base_type(named_type, *type);
-			return true;
-		}
-	case_end;
-
 	case_ast_node(te, TernaryIfExpr, e);
 		Operand o = {};
 		check_expr_or_type(ctx, &o, e);
diff --git a/src/checker.cpp b/src/checker.cpp
index 878435d67..21ca4c398 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -675,55 +675,44 @@ Entity *add_global_entity(Entity *entity, Scope *scope=builtin_pkg->scope) {
 	return entity;
 }
 
-void add_global_constant(String name, Type *type, ExactValue value) {
+void add_global_constant(char const *name, Type *type, ExactValue value) {
 	Entity *entity = alloc_entity(Entity_Constant, nullptr, make_token_ident(name), type);
 	entity->Constant.value = value;
 	add_global_entity(entity);
 }
 
 
-void add_global_string_constant(String name, String value) {
+void add_global_string_constant(char const *name, String const &value) {
 	add_global_constant(name, t_untyped_string, exact_value_string(value));
 }
 
+void add_global_bool_constant(char const *name, bool value) {
+	add_global_constant(name, t_untyped_bool, exact_value_bool(value));
+}
 
 void add_global_type_entity(String name, Type *type) {
 	add_global_entity(alloc_entity_type_name(nullptr, make_token_ident(name), type));
 }
 
 
-
-void init_universal(void) {
-	BuildContext *bc = &build_context;
-
-	// NOTE(bill): No need to free these
-	// gbAllocator a = heap_allocator();
+AstPackage *create_builtin_package(char const *name) {
 	gbAllocator a = permanent_allocator();
+	AstPackage *pkg = gb_alloc_item(a, AstPackage);
+	pkg->name = make_string_c(name);
+	pkg->kind = Package_Normal;
 
-	builtin_pkg = gb_alloc_item(a, AstPackage);
-	builtin_pkg->name = str_lit("builtin");
-	builtin_pkg->kind = Package_Normal;
-
-	builtin_pkg->scope = create_scope(nullptr);
-	builtin_pkg->scope->flags |= ScopeFlag_Pkg | ScopeFlag_Global | ScopeFlag_Builtin;
-	builtin_pkg->scope->pkg = builtin_pkg;
-
-	intrinsics_pkg = gb_alloc_item(a, AstPackage);
-	intrinsics_pkg->name = str_lit("intrinsics");
-	intrinsics_pkg->kind = Package_Normal;
-
-	intrinsics_pkg->scope = create_scope(nullptr);
-	intrinsics_pkg->scope->flags |= ScopeFlag_Pkg | ScopeFlag_Global | ScopeFlag_Builtin;
-	intrinsics_pkg->scope->pkg = intrinsics_pkg;
-
-	config_pkg = gb_alloc_item(a, AstPackage);
-	config_pkg->name = str_lit("config");
-	config_pkg->kind = Package_Normal;
+	pkg->scope = create_scope(nullptr);
+	pkg->scope->flags |= ScopeFlag_Pkg | ScopeFlag_Global | ScopeFlag_Builtin;
+	pkg->scope->pkg = pkg;
+	return pkg;
+}
 
-	config_pkg->scope = create_scope(nullptr);
-	config_pkg->scope->flags |= ScopeFlag_Pkg | ScopeFlag_Global | ScopeFlag_Builtin;
-	config_pkg->scope->pkg = config_pkg;
+void init_universal(void) {
+	BuildContext *bc = &build_context;
 
+	builtin_pkg    = create_builtin_package("builtin");
+	intrinsics_pkg = create_builtin_package("intrinsics");
+	config_pkg     = create_builtin_package("config");
 
 // Types
 	for (isize i = 0; i < gb_count_of(basic_types); i++) {
@@ -740,23 +729,23 @@ void init_universal(void) {
 	}
 
 // Constants
-	add_global_constant(str_lit("true"),  t_untyped_bool, exact_value_bool(true));
-	add_global_constant(str_lit("false"), t_untyped_bool, exact_value_bool(false));
-
 	add_global_entity(alloc_entity_nil(str_lit("nil"), t_untyped_nil));
 
+	add_global_bool_constant("true",  true);
+	add_global_bool_constant("false", false);
+
 	// TODO(bill): Set through flags in the compiler
-	add_global_string_constant(str_lit("ODIN_OS"),      bc->ODIN_OS);
-	add_global_string_constant(str_lit("ODIN_ARCH"),    bc->ODIN_ARCH);
-	add_global_string_constant(str_lit("ODIN_ENDIAN"),  bc->ODIN_ENDIAN);
-	add_global_string_constant(str_lit("ODIN_VENDOR"),  bc->ODIN_VENDOR);
-	add_global_string_constant(str_lit("ODIN_VERSION"), bc->ODIN_VERSION);
-	add_global_string_constant(str_lit("ODIN_ROOT"),    bc->ODIN_ROOT);
-	add_global_constant(str_lit("ODIN_DEBUG"), t_untyped_bool, exact_value_bool(bc->ODIN_DEBUG));
-	add_global_constant(str_lit("ODIN_DISABLE_ASSERT"), t_untyped_bool, exact_value_bool(bc->ODIN_DISABLE_ASSERT));
-	add_global_constant(str_lit("ODIN_DEFAULT_TO_NIL_ALLOCATOR"), t_untyped_bool, exact_value_bool(bc->ODIN_DEFAULT_TO_NIL_ALLOCATOR));
-	add_global_constant(str_lit("ODIN_NO_DYNAMIC_LITERALS"), t_untyped_bool, exact_value_bool(bc->no_dynamic_literals));
-	add_global_constant(str_lit("ODIN_TEST"), t_untyped_bool, exact_value_bool(bc->command_kind == Command_test));
+	add_global_string_constant("ODIN_OS",      bc->ODIN_OS);
+	add_global_string_constant("ODIN_ARCH",    bc->ODIN_ARCH);
+	add_global_string_constant("ODIN_ENDIAN",  bc->ODIN_ENDIAN);
+	add_global_string_constant("ODIN_VENDOR",  bc->ODIN_VENDOR);
+	add_global_string_constant("ODIN_VERSION", bc->ODIN_VERSION);
+	add_global_string_constant("ODIN_ROOT",    bc->ODIN_ROOT);
+	add_global_bool_constant("ODIN_DEBUG",                    bc->ODIN_DEBUG);
+	add_global_bool_constant("ODIN_DISABLE_ASSERT",           bc->ODIN_DISABLE_ASSERT);
+	add_global_bool_constant("ODIN_DEFAULT_TO_NIL_ALLOCATOR", bc->ODIN_DEFAULT_TO_NIL_ALLOCATOR);
+	add_global_bool_constant("ODIN_NO_DYNAMIC_LITERALS",      bc->no_dynamic_literals);
+	add_global_bool_constant("ODIN_TEST",                     bc->command_kind == Command_test);
 
 
 // Builtin Procedures
@@ -801,8 +790,6 @@ void init_universal(void) {
 		}
 		GB_ASSERT(type != nullptr);
 
-
-
 		Entity *entity = alloc_entity_constant(nullptr, make_token_ident(name), type, value);
 		entity->state = EntityState_Resolved;
 		if (scope_insert(config_pkg->scope, entity)) {
@@ -960,7 +947,11 @@ Entity *entity_of_node(Ast *expr) {
 	expr = unparen_expr(expr);
 	switch (expr->kind) {
 	case_ast_node(ident, Ident, expr);
-		return ident->entity;
+		Entity *e = ident->entity;
+		if (e && e->flags & EntityFlag_Overridden) {
+			// GB_PANIC("use of an overriden entity: %.*s", LIT(e->token.string));
+		}
+		return e;
 	case_end;
 	case_ast_node(se, SelectorExpr, expr);
 		Ast *s = unselector_expr(se->selector);
@@ -973,7 +964,6 @@ Entity *entity_of_node(Ast *expr) {
 	return nullptr;
 }
 
-
 DeclInfo *decl_info_of_entity(Entity *e) {
 	if (e != nullptr) {
 		return e->decl_info;
@@ -1870,7 +1860,8 @@ void generate_minimum_dependency_set(Checker *c, Entity *start) {
 				continue;
 			}
 
-			if (e->file == nullptr || !e->file->is_test) {
+			// if (e->file == nullptr || !e->file->is_test) {
+			if (e->file == nullptr) {
 				continue;
 			}
 
@@ -2675,206 +2666,6 @@ DECL_ATTRIBUTE_PROC(type_decl_attribute) {
 	if (name == "private") {
 		// NOTE(bill): Handled elsewhere `check_collect_value_decl`
 		return true;
-	} else if (name == "index_get") {
-		if (value != nullptr) {
-			Operand o = {};
-			check_expr_or_type(c, &o, value);
-			Entity *e = entity_of_node(value);
-			if (e != nullptr && e->kind == Entity_Procedure) {
-				if (ac->deferred_procedure.entity != nullptr) {
-					error(elem, "Previous usage of the '%.*s' attribute", LIT(name));
-				}
-
-				bool valid = true;
-
-				{
-					Type *pt = base_type(e->type);
-					GB_ASSERT(pt->kind == Type_Proc);
-
-					if (pt->Proc.result_count == 0) {
-						error(value, "'%s' attribute must return something", LIT(name));
-						valid = false;
-					}
-
-					if (pt->Proc.param_count < 2) {
-						error(value, "'%s' attribute must allow for 2 parameters", LIT(name));
-						valid = false;
-					} else {
-						isize minimum_param_count = 0;
-						for_array(i, pt->Proc.params->Tuple.variables) {
-							Entity *param = pt->Proc.params->Tuple.variables[i];
-							if (param->kind == Entity_Variable) {
-								if (param->Variable.param_value.kind == ParameterValue_Invalid) {
-									minimum_param_count += 1;
-								} else {
-									break;
-								}
-							} else if (param->kind == Entity_Constant) {
-								minimum_param_count += 1;
-							} else {
-								break;
-							}
-						}
-
-						if (minimum_param_count > 2) {
-							error(value, "'%s' attribute must allow for at a minimum 2 parameters", LIT(name));
-							valid = false;
-						}
-					}
-				}
-
-				if (valid) {
-					if (ac->atom_op_table == nullptr) {
-						ac->atom_op_table = gb_alloc_item(permanent_allocator(), TypeAtomOpTable);
-					}
-					ac->atom_op_table->op[TypeAtomOp_index_get] = e;
-				}
-				return true;
-			}
-		}
-		error(elem, "Expected a procedure entity for '%.*s'", LIT(name));
-		return false;
-	} else if (name == "index_set") {
-		if (value != nullptr) {
-			Operand o = {};
-			check_expr_or_type(c, &o, value);
-			Entity *e = entity_of_node(value);
-			if (e != nullptr && e->kind == Entity_Procedure) {
-				if (ac->deferred_procedure.entity != nullptr) {
-					error(elem, "Previous usage of the '%.*s' attribute", LIT(name));
-				}
-
-				bool valid = true;
-
-				{
-					Type *pt = base_type(e->type);
-					GB_ASSERT(pt->kind == Type_Proc);
-
-					if (pt->Proc.param_count < 3) {
-						error(value, "'%s' attribute must allow for 3 parameters", LIT(name));
-						valid = false;
-					} else {
-						isize minimum_param_count = 0;
-						for_array(i, pt->Proc.params->Tuple.variables) {
-							Entity *param = pt->Proc.params->Tuple.variables[i];
-							if (param->kind == Entity_Variable) {
-								if (param->Variable.param_value.kind == ParameterValue_Invalid) {
-									minimum_param_count += 1;
-								} else {
-									break;
-								}
-							} else if (param->kind == Entity_Constant) {
-								minimum_param_count += 1;
-							} else {
-								break;
-							}
-						}
-
-						if (minimum_param_count > 3) {
-							error(value, "'%s' attribute must allow for at a minimum 3 parameters", LIT(name));
-							valid = false;
-						}
-					}
-
-					if (pt->Proc.variadic || pt->Proc.c_vararg) {
-						error(value, "'%s' attribute does not allow variadic procedures", LIT(name));
-						valid = false;
-					}
-				}
-
-				if (valid) {
-					if (ac->atom_op_table == nullptr) {
-						ac->atom_op_table = gb_alloc_item(permanent_allocator(), TypeAtomOpTable);
-					}
-					ac->atom_op_table->op[TypeAtomOp_index_set] = e;
-				}
-				return true;
-			}
-		}
-		error(elem, "Expected a procedure entity for '%.*s'", LIT(name));
-		return false;
-	} else if (name == "slice") {
-		if (value != nullptr) {
-			Operand o = {};
-			check_expr_or_type(c, &o, value);
-			Entity *e = entity_of_node(value);
-			if (e != nullptr && e->kind == Entity_Procedure) {
-				if (ac->deferred_procedure.entity != nullptr) {
-					error(elem, "Previous usage of the '%.*s' attribute", LIT(name));
-				}
-
-				bool valid = true;
-
-				{
-					Type *pt = base_type(e->type);
-					GB_ASSERT(pt->kind == Type_Proc);
-
-					if (pt->Proc.param_count < 1) {
-						error(value, "'%s' attribute must allow for 1 parameter", LIT(name));
-						valid = false;
-					} else {
-						isize minimum_param_count = 0;
-						for_array(i, pt->Proc.params->Tuple.variables) {
-							Entity *param = pt->Proc.params->Tuple.variables[i];
-							if (param->kind == Entity_Variable) {
-								if (param->Variable.param_value.kind == ParameterValue_Invalid) {
-									minimum_param_count += 1;
-								} else {
-									break;
-								}
-							} else if (param->kind == Entity_Constant) {
-								minimum_param_count += 1;
-							} else {
-								break;
-							}
-						}
-
-						if (minimum_param_count > 1) {
-							error(value, "'%s' attribute must allow for at a minimum 1 parameter", LIT(name));
-							valid = false;
-						}
-						{
-							Entity *param = pt->Proc.params->Tuple.variables[0];
-							Type *param_type = base_type(param->type);
-							if (is_type_pointer(param_type) && !is_type_rawptr(param_type)) {
-								// okay
-							} else {
-								error(value, "'%s' attribute's first parameter must be a pointer", LIT(name));
-								valid = false;
-							}
-
-						}
-					}
-
-					if (pt->Proc.variadic || pt->Proc.c_vararg) {
-						error(value, "'%s' attribute does not allow variadic procedures", LIT(name));
-						valid = false;
-					}
-
-					if (pt->Proc.result_count != 1) {
-						error(value, "'%s' attribute must return 1 result", LIT(name));
-						valid = false;
-					} else {
-						Type *rt = pt->Proc.results->Tuple.variables[0]->type;
-						rt = base_type(rt);
-						if (!is_type_slice(rt)) {
-							error(value, "'%s' attribute must return a slice", LIT(name));
-							valid = false;
-						}
-					}
-				}
-
-				if (valid) {
-					if (ac->atom_op_table == nullptr) {
-						ac->atom_op_table = gb_alloc_item(permanent_allocator(), TypeAtomOpTable);
-					}
-					ac->atom_op_table->op[TypeAtomOp_slice] = e;
-				}
-				return true;
-			}
-		}
-		error(elem, "Expected a procedure entity for '%.*s'", LIT(name));
-		return false;
 	}
 	return false;
 }
@@ -4498,6 +4289,38 @@ void check_unchecked_bodies(Checker *c) {
 	}
 }
 
+void check_test_names(Checker *c) {
+	if (build_context.test_names.entries.count == 0) {
+		return;
+	}
+
+	AstPackage *pkg = c->info.init_package;
+	Scope *s = pkg->scope;
+
+	for_array(i, build_context.test_names.entries) {
+		String name = build_context.test_names.entries[i].value;
+		Entity *e = scope_lookup(s, name);
+		if (e == nullptr) {
+			Token tok = {};
+			if (pkg->files.count != 0) {
+				tok = pkg->files[0]->tokens[0];
+			}
+			error(tok, "Unable to find the test '%.*s' in 'package %.*s' ", LIT(name), LIT(pkg->name));
+		}
+	}
+
+	for (isize i = 0; i < c->info.testing_procedures.count; /**/) {
+		Entity *e = c->info.testing_procedures[i];
+		String name = e->token.string;
+		if (!string_set_exists(&build_context.test_names, name)) {
+			array_ordered_remove(&c->info.testing_procedures, i);
+		} else {
+			i += 1;
+		}
+	}
+
+}
+
 void check_parsed_files(Checker *c) {
 #define TIME_SECTION(str) do { if (build_context.show_more_timings) timings_start_section(&global_timings, str_lit(str)); } while (0)
 
@@ -4572,6 +4395,9 @@ void check_parsed_files(Checker *c) {
 	TIME_SECTION("generate minimum dependency set");
 	generate_minimum_dependency_set(c, c->info.entry_point);
 
+	TIME_SECTION("check test names");
+	check_test_names(c);
+
 	TIME_SECTION("calculate global init order");
 	// Calculate initialization order of global variables
 	calculate_global_init_order(c);
diff --git a/src/checker.hpp b/src/checker.hpp
index 4ff72717d..38628ed51 100644
--- a/src/checker.hpp
+++ b/src/checker.hpp
@@ -114,7 +114,6 @@ struct AttributeContext {
 	String  deprecated_message;
 	DeferredProcedure deferred_procedure;
 	u32 optimization_mode; // ProcedureOptimizationMode
-	struct TypeAtomOpTable *atom_op_table;
 };
 
 AttributeContext make_attribute_context(String link_prefix) {
@@ -335,7 +334,6 @@ struct CheckerContext {
 	Scope *    polymorphic_scope;
 
 	Ast *assignment_lhs_hint;
-	Ast *unary_address_hint;
 };
 
 struct Checker {
diff --git a/src/checker_builtin_procs.hpp b/src/checker_builtin_procs.hpp
index 98ef5180b..b69bacd30 100644
--- a/src/checker_builtin_procs.hpp
+++ b/src/checker_builtin_procs.hpp
@@ -56,6 +56,11 @@ enum BuiltinProcId {
 	BuiltinProc_overflow_sub,
 	BuiltinProc_overflow_mul,
 
+	BuiltinProc_sqrt,
+
+	BuiltinProc_mem_copy,
+	BuiltinProc_mem_copy_non_overlapping,
+
 	BuiltinProc_volatile_store,
 	BuiltinProc_volatile_load,
 
@@ -197,6 +202,8 @@ BuiltinProc__type_simple_boolean_end,
 
 	BuiltinProc_type_is_specialization_of,
 
+	BuiltinProc_type_is_variant_of,
+
 	BuiltinProc_type_struct_field_count,
 
 	BuiltinProc_type_proc_parameter_count,
@@ -276,6 +283,11 @@ gb_global BuiltinProc builtin_procs[BuiltinProc_COUNT] = {
 	{STR_LIT("overflow_sub"), 2, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 	{STR_LIT("overflow_mul"), 2, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 
+	{STR_LIT("sqrt"), 1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
+
+	{STR_LIT("mem_copy"),                 3, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
+	{STR_LIT("mem_copy_non_overlapping"), 3, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
+
 	{STR_LIT("volatile_store"),  2, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
 	{STR_LIT("volatile_load"),   1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 
@@ -415,6 +427,8 @@ gb_global BuiltinProc builtin_procs[BuiltinProc_COUNT] = {
 
 	{STR_LIT("type_is_specialization_of"), 2, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 
+	{STR_LIT("type_is_variant_of"), 2, false, Expr_Expr, BuiltinProcPkg_intrinsics},
+
 	{STR_LIT("type_struct_field_count"),   1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 
 	{STR_LIT("type_proc_parameter_count"), 1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
diff --git a/src/docs_writer.cpp b/src/docs_writer.cpp
index f4fd02376..03ea25930 100644
--- a/src/docs_writer.cpp
+++ b/src/docs_writer.cpp
@@ -697,6 +697,9 @@ OdinDocTypeIndex odin_doc_type(OdinDocWriter *w, Type *type) {
 			case ProcCC_None:
 				calling_convention = str_lit("none");
 				break;
+			case ProcCC_Naked:
+				calling_convention = str_lit("naked");
+				break;
 			case ProcCC_InlineAsm:
 				calling_convention = str_lit("inline-assembly");
 				break;
diff --git a/src/entity.cpp b/src/entity.cpp
index d1f4c78e6..460f4ec6d 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -126,6 +126,8 @@ struct Entity {
 	Entity *    using_parent;
 	Ast *       using_expr;
 
+	Entity *    aliased_of;
+
 	lbModule *   code_gen_module;
 	lbProcedure *code_gen_procedure;
 
diff --git a/src/llvm_abi.cpp b/src/llvm_abi.cpp
index 65e3b2c58..aba85ae83 100644
--- a/src/llvm_abi.cpp
+++ b/src/llvm_abi.cpp
@@ -10,21 +10,35 @@ struct lbArgType {
 	LLVMTypeRef cast_type;      // Optional
 	LLVMTypeRef pad_type;       // Optional
 	LLVMAttributeRef attribute; // Optional
+	LLVMAttributeRef align_attribute; // Optional
 };
 
+
+i64 lb_sizeof(LLVMTypeRef type);
+i64 lb_alignof(LLVMTypeRef type);
+
 lbArgType lb_arg_type_direct(LLVMTypeRef type, LLVMTypeRef cast_type, LLVMTypeRef pad_type, LLVMAttributeRef attr) {
-	return lbArgType{lbArg_Direct, type, cast_type, pad_type, attr};
+	return lbArgType{lbArg_Direct, type, cast_type, pad_type, attr, nullptr};
 }
 lbArgType lb_arg_type_direct(LLVMTypeRef type) {
 	return lb_arg_type_direct(type, nullptr, nullptr, nullptr);
 }
 
 lbArgType lb_arg_type_indirect(LLVMTypeRef type, LLVMAttributeRef attr) {
-	return lbArgType{lbArg_Indirect, type, nullptr, nullptr, attr};
+	return lbArgType{lbArg_Indirect, type, nullptr, nullptr, attr, nullptr};
+}
+
+lbArgType lb_arg_type_indirect_byval(LLVMContextRef c, LLVMTypeRef type) {
+	i64 alignment = lb_alignof(type);
+	alignment = gb_max(alignment, 8);
+
+	LLVMAttributeRef byval_attr = lb_create_enum_attribute_with_type(c, "byval", type);
+	LLVMAttributeRef align_attr = lb_create_enum_attribute(c, "align", alignment);
+	return lbArgType{lbArg_Indirect, type, nullptr, nullptr, byval_attr, align_attr};
 }
 
 lbArgType lb_arg_type_ignore(LLVMTypeRef type) {
-	return lbArgType{lbArg_Ignore, type, nullptr, nullptr, nullptr};
+	return lbArgType{lbArg_Ignore, type, nullptr, nullptr, nullptr, nullptr};
 }
 
 struct lbFunctionType {
@@ -121,6 +135,9 @@ void lb_add_function_type_attributes(LLVMValueRef fn, lbFunctionType *ft, ProcCa
 		if (arg->attribute) {
 			LLVMAddAttributeAtIndex(fn, arg_index+1, arg->attribute);
 		}
+		if (arg->align_attribute) {
+			LLVMAddAttributeAtIndex(fn, arg_index+1, arg->align_attribute);
+		}
 
 		arg_index++;
 	}
@@ -145,8 +162,6 @@ void lb_add_function_type_attributes(LLVMValueRef fn, lbFunctionType *ft, ProcCa
 
 }
 
-i64 lb_sizeof(LLVMTypeRef type);
-i64 lb_alignof(LLVMTypeRef type);
 
 i64 lb_sizeof(LLVMTypeRef type) {
 	LLVMTypeKind kind = LLVMGetTypeKind(type);
@@ -271,110 +286,6 @@ i64 lb_alignof(LLVMTypeRef type) {
 	return 1;
 }
 
-#if 0
-Type *lb_abi_to_odin_type(lbModule *m, LLVMTypeRef type, bool is_return, u32 level = 0) {
-	Type **found = map_get(&m->llvm_types, hash_pointer(type));
-	if (found) {
-		return *found;
-	}
-	GB_ASSERT_MSG(level < 64, "%s %d", LLVMPrintTypeToString(type), is_return);
-
-	LLVMTypeKind kind = LLVMGetTypeKind(type);
-	switch (kind) {
-	case LLVMVoidTypeKind:
-		return nullptr;
-	case LLVMIntegerTypeKind:
-		{
-			unsigned w = LLVMGetIntTypeWidth(type);
-			if (w == 1) {
-				return t_llvm_bool;
-			}
-			unsigned bytes = (w + 7)/8;
-			switch (bytes) {
-			case 1:  return t_u8;
-			case 2:  return t_u16;
-			case 4:  return t_u32;
-			case 8:  return t_u64;
-			case 16: return t_u128;
-			}
-			GB_PANIC("Unhandled integer type");
-		}
-	case LLVMFloatTypeKind:
-		return t_f32;
-	case LLVMDoubleTypeKind:
-		return t_f64;
-	case LLVMPointerTypeKind:
-		{
-			LLVMTypeRef elem = LLVMGetElementType(type);
-			if (lb_is_type_kind(elem, LLVMFunctionTypeKind)) {
-				unsigned param_count = LLVMCountParamTypes(elem);
-				LLVMTypeRef *params = gb_alloc_array(heap_allocator(), LLVMTypeRef, param_count);
-				defer (gb_free(heap_allocator(), params));
-				LLVMGetParamTypes(elem, params);
-
-				Type **param_types = gb_alloc_array(heap_allocator(), Type *, param_count);
-				defer (gb_free(heap_allocator(), param_types));
-
-				for (unsigned i = 0; i < param_count; i++) {
-					param_types[i] = lb_abi_to_odin_type(m, params[i], false, level+1);
-				}
-
-				LLVMTypeRef ret = LLVMGetReturnType(elem);
-				Type *ret_type = lb_abi_to_odin_type(m, ret, true, level+1);
-
-				bool is_c_vararg = !!LLVMIsFunctionVarArg(elem);
-				return alloc_type_proc_from_types(param_types, param_count, ret_type, is_c_vararg);
-			}
-			return alloc_type_pointer(lb_abi_to_odin_type(m, elem, false, level+1));
-		}
-	case LLVMFunctionTypeKind:
-		GB_PANIC("LLVMFunctionTypeKind should not be seen on its own");
-		break;
-
-	case LLVMStructTypeKind:
-		{
-			unsigned field_count = LLVMCountStructElementTypes(type);
-			Type **fields = gb_alloc_array(heap_allocator(), Type *, field_count);
-			for (unsigned i = 0; i < field_count; i++) {
-				LLVMTypeRef field_type = LLVMStructGetTypeAtIndex(type, i);
-				if (lb_is_type_kind(field_type, LLVMPointerTypeKind) && level > 0) {
-					fields[i] = t_rawptr;
-				} else {
-					fields[i] = lb_abi_to_odin_type(m, field_type, false, level+1);
-				}
-			}
-			if (is_return) {
-				return alloc_type_tuple_from_field_types(fields, field_count, !!LLVMIsPackedStruct(type), false);
-			} else {
-				return alloc_type_struct_from_field_types(fields, field_count, !!LLVMIsPackedStruct(type));
-			}
-		}
-		break;
-	case LLVMArrayTypeKind:
-		{
-
-			i64 count = LLVMGetArrayLength(type);
-			Type *elem = lb_abi_to_odin_type(m, LLVMGetElementType(type), false, level+1);
-			return alloc_type_array(elem, count);
-		}
-		break;
-
-	case LLVMX86_MMXTypeKind:
-		return t_vector_x86_mmx;
-	case LLVMVectorTypeKind:
-		{
-			i64 count = LLVMGetVectorSize(type);
-			Type *elem = lb_abi_to_odin_type(m, LLVMGetElementType(type), false, level+1);
-			return alloc_type_simd_vector(count, elem);
-		}
-
-	}
-	GB_PANIC("Unhandled type for lb_abi_to_odin_type -> %s", LLVMPrintTypeToString(type));
-
-	return 0;
-}
-#endif
-
 
 #define LB_ABI_INFO(name) lbFunctionType *name(LLVMContextRef c, LLVMTypeRef *arg_types, unsigned arg_count, LLVMTypeRef return_type, bool return_is_defined, ProcCallingConvention calling_convention)
 typedef LB_ABI_INFO(lbAbiInfoType);
@@ -432,7 +343,7 @@ namespace lbAbi386 {
 				if (sz == 0) {
 					args[i] = lb_arg_type_ignore(t);
 				} else {
-					args[i] = lb_arg_type_indirect(t, lb_create_enum_attribute(c, "byval"));
+					args[i] = lb_arg_type_indirect(t, nullptr);
 				}
 			} else {
 				args[i] = non_struct(c, t, false);
@@ -452,7 +363,7 @@ namespace lbAbi386 {
 			case 4: return lb_arg_type_direct(return_type, LLVMIntTypeInContext(c, 32), nullptr, nullptr);
 			case 8: return lb_arg_type_direct(return_type, LLVMIntTypeInContext(c, 64), nullptr, nullptr);
 			}
-			LLVMAttributeRef attr = lb_create_enum_attribute(c, "sret");
+			LLVMAttributeRef attr = lb_create_enum_attribute_with_type(c, "sret", return_type);
 			return lb_arg_type_indirect(return_type, attr);
 		}
 		return non_struct(c, return_type, true);
@@ -523,8 +434,14 @@ namespace lbAbiAmd64SysV {
 		switch (reg_class) {
 		case RegClass_SSEFs:
 		case RegClass_SSEFv:
+		case RegClass_SSEDs:
 		case RegClass_SSEDv:
 			return true;
+		case RegClass_SSEInt8:
+		case RegClass_SSEInt16:
+		case RegClass_SSEInt32:
+		case RegClass_SSEInt64:
+			return true;
 		}
 		return false;
 	}
@@ -610,9 +527,9 @@ namespace lbAbiAmd64SysV {
 		if (is_mem_cls(cls, attribute_kind)) {
 			LLVMAttributeRef attribute = nullptr;
 			if (attribute_kind == Amd64TypeAttribute_ByVal) {
-				attribute = lb_create_enum_attribute(c, "byval");
+				return lb_arg_type_indirect_byval(c, type);
 			} else if (attribute_kind == Amd64TypeAttribute_StructRect) {
-				attribute = lb_create_enum_attribute(c, "sret");
+				attribute = lb_create_enum_attribute_with_type(c, "sret", type);
 			}
 			return lb_arg_type_indirect(type, attribute);
 		} else {
@@ -642,30 +559,48 @@ namespace lbAbiAmd64SysV {
 		return reg_classes;
 	}
 
-	void unify(Array<RegClass> *cls, i64 i, RegClass newv) {
-		RegClass &oldv = (*cls)[i];
+	void unify(Array<RegClass> *cls, i64 i, RegClass const newv) {
+		RegClass const oldv = (*cls)[i];
 		if (oldv == newv) {
 			return;
-		} else if (oldv == RegClass_NoClass) {
-			oldv = newv;
+		}
+
+		RegClass to_write = newv;
+		if (oldv == RegClass_NoClass) {
+			to_write = newv;
 		} else if (newv == RegClass_NoClass) {
 			return;
 		} else if (oldv == RegClass_Memory || newv == RegClass_Memory) {
-			return;
-		} else if (oldv == RegClass_Int || newv	== RegClass_Int) {
-			return;
-		} else if (oldv == RegClass_X87 || oldv == RegClass_X87Up || oldv == RegClass_ComplexX87 ||
-		           newv == RegClass_X87 || newv == RegClass_X87Up || newv == RegClass_ComplexX87) {
-			oldv = RegClass_Memory;
-		} else {
-			oldv = newv;
+			to_write = RegClass_Memory;
+		} else if (oldv == RegClass_Int || newv == RegClass_Int) {
+			to_write = RegClass_Int;
+		} else if (oldv == RegClass_X87 || oldv == RegClass_X87Up || oldv == RegClass_ComplexX87) {
+			to_write = RegClass_Memory;
+		} else if (newv == RegClass_X87 || newv == RegClass_X87Up || newv == RegClass_ComplexX87) {
+			to_write = RegClass_Memory;
+		} else if (newv == RegClass_SSEUp) {
+			switch (oldv) {
+			case RegClass_SSEFv:
+			case RegClass_SSEFs:
+			case RegClass_SSEDv:
+			case RegClass_SSEDs:
+			case RegClass_SSEInt8:
+			case RegClass_SSEInt16:
+			case RegClass_SSEInt32:
+			case RegClass_SSEInt64:
+				return;
+			}
 		}
+
+		(*cls)[i] = to_write;
 	}
 
 	void fixup(LLVMTypeRef t, Array<RegClass> *cls) {
 		i64 i = 0;
 		i64 e = cls->count;
-		if (e > 2 && (lb_is_type_kind(t, LLVMStructTypeKind) || lb_is_type_kind(t, LLVMArrayTypeKind))) {
+		if (e > 2 && (lb_is_type_kind(t, LLVMStructTypeKind) ||
+		              lb_is_type_kind(t, LLVMArrayTypeKind) ||
+		              lb_is_type_kind(t, LLVMVectorTypeKind))) {
 			RegClass &oldv = (*cls)[i];
 			if (is_sse(oldv)) {
 				for (i++; i < e; i++) {
@@ -709,8 +644,8 @@ namespace lbAbiAmd64SysV {
 
 	unsigned llvec_len(Array<RegClass> const &reg_classes, isize offset) {
 		unsigned len = 1;
-		for (isize i = offset+1; i < reg_classes.count; i++) {
-			if (reg_classes[offset] != RegClass_SSEFv && reg_classes[i] != RegClass_SSEUp) {
+		for (isize i = offset; i < reg_classes.count; i++) {
+			if (reg_classes[i] != RegClass_SSEUp) {
 				break;
 			}
 			len++;
@@ -721,7 +656,7 @@ namespace lbAbiAmd64SysV {
 
 	LLVMTypeRef llreg(LLVMContextRef c, Array<RegClass> const &reg_classes) {
 		auto types = array_make<LLVMTypeRef>(heap_allocator(), 0, reg_classes.count);
-		for_array(i, reg_classes) {
+		for (isize i = 0; i < reg_classes.count; /**/) {
 			RegClass reg_class = reg_classes[i];
 			switch (reg_class) {
 			case RegClass_Int:
@@ -763,7 +698,7 @@ namespace lbAbiAmd64SysV {
 						break;
 					}
 
-					unsigned vec_len = llvec_len(reg_classes, i);
+					unsigned vec_len = llvec_len(reg_classes, i+1);
 					LLVMTypeRef vec_type = LLVMVectorType(elem_type, vec_len * elems_per_word);
 					array_add(&types, vec_type);
 					i += vec_len;
@@ -779,9 +714,9 @@ namespace lbAbiAmd64SysV {
 			default:
 				GB_PANIC("Unhandled RegClass");
 			}
+			i += 1;
 		}
 
-		GB_ASSERT(types.count != 0);
 		if (types.count == 1) {
 			return types[0];
 		}
@@ -893,7 +828,7 @@ namespace lbAbiAmd64SysV {
 				if (sz == 0) {
 					args[i] = lb_arg_type_ignore(t);
 				} else {
-					args[i] = lb_arg_type_indirect(t, lb_create_enum_attribute(c, "byval"));
+					args[i] = lb_arg_type_indirect_byval(c, t);
 				}
 			} else {
 				args[i] = non_struct(c, t);
@@ -913,7 +848,7 @@ namespace lbAbiAmd64SysV {
 			case 4: return lb_arg_type_direct(return_type, LLVMIntTypeInContext(c, 32), nullptr, nullptr);
 			case 8: return lb_arg_type_direct(return_type, LLVMIntTypeInContext(c, 64), nullptr, nullptr);
 			}
-			LLVMAttributeRef attr = lb_create_enum_attribute(c, "sret");
+			LLVMAttributeRef attr = lb_create_enum_attribute_with_type(c, "sret", return_type);
 			return lb_arg_type_indirect(return_type, attr);
 		} else if (build_context.metrics.os == TargetOs_windows && lb_is_type_kind(return_type, LLVMIntegerTypeKind) && lb_sizeof(return_type) == 16) {
 			return lb_arg_type_direct(return_type, LLVMIntTypeInContext(c, 128), nullptr, nullptr);
@@ -1063,7 +998,7 @@ namespace lbAbiArm64 {
 				}
 				return lb_arg_type_direct(type, cast_type, nullptr, nullptr);
 			} else {
-				LLVMAttributeRef attr = lb_create_enum_attribute(c, "sret");
+				LLVMAttributeRef attr = lb_create_enum_attribute_with_type(c, "sret", type);
 				return lb_arg_type_indirect(type, attr);
 			}
 		}
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index 758f8e5d1..08c9445bd 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -1,8 +1,21 @@
+#define MULTITHREAD_OBJECT_GENERATION 1
+
+#ifndef USE_SEPARTE_MODULES
+#define USE_SEPARTE_MODULES build_context.use_separate_modules
+#endif
+
+#ifndef MULTITHREAD_OBJECT_GENERATION
+#define MULTITHREAD_OBJECT_GENERATION 0
+#endif
+
+
 #include "llvm_backend.hpp"
 #include "llvm_abi.cpp"
 #include "llvm_backend_opt.cpp"
 
-gb_global lbAddr lb_global_type_info_data           = {};
+gb_global ThreadPool lb_thread_pool = {};
+
+gb_global Entity *lb_global_type_info_data_entity   = {};
 gb_global lbAddr lb_global_type_info_member_types   = {};
 gb_global lbAddr lb_global_type_info_member_names   = {};
 gb_global lbAddr lb_global_type_info_member_offsets = {};
@@ -17,6 +30,12 @@ gb_global isize lb_global_type_info_member_usings_index  = 0;
 gb_global isize lb_global_type_info_member_tags_index    = 0;
 
 
+lbValue lb_global_type_info_data_ptr(lbModule *m) {
+	lbValue v = lb_find_value_from_entity(m, lb_global_type_info_data_entity);
+	return v;
+}
+
+
 struct lbLoopData {
 	lbAddr idx_addr;
 	lbValue idx;
@@ -74,6 +93,15 @@ bool lb_is_instr_terminating(LLVMValueRef instr) {
 
 
 
+lbModule *lb_pkg_module(lbGenerator *gen, AstPackage *pkg) {
+	auto *found = map_get(&gen->modules, hash_pointer(pkg));
+	if (found) {
+		return *found;
+	}
+	return &gen->default_module;
+}
+
+
 lbAddr lb_addr(lbValue addr) {
 	lbAddr v = {lbAddr_Default, addr};
 	if (addr.type != nullptr && is_type_relative_pointer(type_deref(addr.type))) {
@@ -184,7 +212,7 @@ void lb_emit_bounds_check(lbProcedure *p, Token token, lbValue index, lbValue le
 	if (build_context.no_bounds_check) {
 		return;
 	}
-	if ((p->module->state_flags & StateFlag_no_bounds_check) != 0) {
+	if ((p->state_flags & StateFlag_no_bounds_check) != 0) {
 		return;
 	}
 
@@ -209,7 +237,7 @@ void lb_emit_slice_bounds_check(lbProcedure *p, Token token, lbValue low, lbValu
 	if (build_context.no_bounds_check) {
 		return;
 	}
-	if ((p->module->state_flags & StateFlag_no_bounds_check) != 0) {
+	if ((p->state_flags & StateFlag_no_bounds_check) != 0) {
 		return;
 	}
 
@@ -372,18 +400,7 @@ void lb_addr_store(lbProcedure *p, lbAddr addr, lbValue value) {
 		GB_ASSERT(is_type_polymorphic(e->type));
 
 		{
-			lbValue *found = nullptr;
-			if (p->module != e->code_gen_module) {
-				gb_mutex_lock(&p->module->mutex);
-			}
-			GB_ASSERT(e->code_gen_module != nullptr);
-			found = map_get(&e->code_gen_module->values, hash_entity(e));
-			if (p->module != e->code_gen_module) {
-				gb_mutex_unlock(&p->module->mutex);
-			}
-			GB_ASSERT_MSG(found != nullptr, "%.*s", LIT(e->token.string));
-
-			lb_emit_call(p, *found, args);
+			lb_emit_call(p, lb_find_procedure_value_from_entity(p->module, e), args);
 		}
 
 		return;
@@ -501,6 +518,38 @@ void lb_const_store(lbValue ptr, lbValue value) {
 }
 
 
+bool lb_is_type_proc_recursive(Type *t) {
+	for (;;) {
+		if (t == nullptr) {
+			return false;
+		}
+		switch (t->kind) {
+		case Type_Named:
+			t = t->Named.base;
+			break;
+		case Type_Pointer:
+			t = t->Pointer.elem;
+			break;
+		case Type_Array:
+			t = t->Array.elem;
+			break;
+		case Type_EnumeratedArray:
+			t = t->EnumeratedArray.elem;
+			break;
+		case Type_Slice:
+			t = t->Slice.elem;
+			break;
+		case Type_DynamicArray:
+			t = t->DynamicArray.elem;
+			break;
+		case Type_Proc:
+			return true;
+		default:
+			return false;
+		}
+	}
+}
+
 void lb_emit_store(lbProcedure *p, lbValue ptr, lbValue value) {
 	GB_ASSERT(value.value != nullptr);
 	Type *a = type_deref(ptr.type);
@@ -513,7 +562,7 @@ void lb_emit_store(lbProcedure *p, lbValue ptr, lbValue value) {
 		GB_ASSERT_MSG(are_types_identical(ca, core_type(value.type)), "%s != %s", type_to_string(a), type_to_string(value.type));
 	}
 
-	if (is_type_proc(a)) {
+	if (lb_is_type_proc_recursive(a)) {
 		// NOTE(bill, 2020-11-11): Because of certain LLVM rules, a procedure value may be
 		// stored as regular pointer with no procedure information
 
@@ -1110,7 +1159,7 @@ LLVMTypeRef lb_type_internal(lbModule *m, Type *type) {
 
 		case Basic_uintptr: return LLVMIntTypeInContext(ctx, 8*cast(unsigned)build_context.word_size);
 
-		case Basic_rawptr: return LLVMPointerType(LLVMInt8Type(), 0);
+		case Basic_rawptr: return LLVMPointerType(LLVMInt8TypeInContext(ctx), 0);
 		case Basic_string:
 			{
 				char const *name = "..string";
@@ -1126,7 +1175,7 @@ LLVMTypeRef lb_type_internal(lbModule *m, Type *type) {
 				LLVMStructSetBody(type, fields, 2, false);
 				return type;
 			}
-		case Basic_cstring: return LLVMPointerType(LLVMInt8Type(), 0);
+		case Basic_cstring: return LLVMPointerType(LLVMInt8TypeInContext(ctx), 0);
 		case Basic_any:
 			{
 				char const *name = "..any";
@@ -1452,21 +1501,35 @@ LLVMTypeRef lb_type_internal(lbModule *m, Type *type) {
 			}
 			if (param_index < param_count) {
 				params[param_index++] = lb_type(m, t_rawptr);
-				// params[param_index++] = lb_type(m, t_context_ptr);
 			}
 			GB_ASSERT(param_index == param_count);
 
-
 			lbFunctionType *ft = lb_get_abi_info(m->ctx, params, param_count, ret, ret != nullptr, type->Proc.calling_convention);
+			{
+				for_array(j, ft->args) {
+					auto arg = ft->args[j];
+					GB_ASSERT_MSG(LLVMGetTypeContext(arg.type) == ft->ctx,
+					              "\n\t%s %td/%td"
+					              "\n\tArgTypeCtx: %p\n\tCurrentCtx: %p\n\tGlobalCtx:  %p",
+					              LLVMPrintTypeToString(arg.type),
+					              j, ft->args.count,
+					              LLVMGetTypeContext(arg.type), ft->ctx, LLVMGetGlobalContext());
+				}
+				GB_ASSERT_MSG(LLVMGetTypeContext(ft->ret.type) == ft->ctx,
+				              "\n\t%s"
+				              "\n\tRetTypeCtx: %p\n\tCurrentCtx: %p\n\tGlobalCtx:  %p",
+				              LLVMPrintTypeToString(ft->ret.type),
+				              LLVMGetTypeContext(ft->ret.type), ft->ctx, LLVMGetGlobalContext());
+			}
+
 			map_set(&m->function_type_map, hash_type(type), ft);
 			LLVMTypeRef new_abi_fn_ptr_type = lb_function_type_to_llvm_ptr(ft, type->Proc.c_vararg);
 			LLVMTypeRef new_abi_fn_type = LLVMGetElementType(new_abi_fn_ptr_type);
 
-			// LLVMTypeRef new_ret = LLVMGetReturnType(new_abi_fn_type);
-			// LLVMTypeRef old_ret = LLVMGetReturnType(old_abi_fn_type);
-			// unsigned new_count = LLVMCountParamTypes(new_abi_fn_type);
-			// unsigned old_count = LLVMCountParamTypes(old_abi_fn_type);
-			// GB_ASSERT_MSG(new_count == old_count, "%u %u, %s %s", new_count, old_count, LLVMPrintTypeToString(new_abi_fn_type), LLVMPrintTypeToString(old_abi_fn_type));
+			GB_ASSERT_MSG(LLVMGetTypeContext(new_abi_fn_type) == m->ctx,
+			              "\n\tFuncTypeCtx: %p\n\tCurrentCtx:  %p\n\tGlobalCtx:   %p",
+			              LLVMGetTypeContext(new_abi_fn_type), m->ctx, LLVMGetGlobalContext());
+
 			return new_abi_fn_ptr_type;
 		}
 
@@ -1823,13 +1886,32 @@ LLVMMetadataRef lb_debug_type_internal(lbModule *m, Type *type) {
 	case Type_Pointer:
 		return LLVMDIBuilderCreatePointerType(m->debug_builder, lb_debug_type(m, type->Pointer.elem), word_bits, word_bits, 0, nullptr, 0);
 
-	case Type_Array:
+	case Type_Array: {
+		LLVMMetadataRef subscripts[1] = {};
+		subscripts[0] = LLVMDIBuilderGetOrCreateSubrange(m->debug_builder,
+			0ll,
+			type->Array.count
+		);
+
 		return LLVMDIBuilderCreateArrayType(m->debug_builder,
-			type->Array.count, 8*cast(unsigned)type_align_of(type), lb_debug_type(m, type->Array.elem), nullptr, 0);
+			8*cast(uint64_t)type_size_of(type),
+			8*cast(unsigned)type_align_of(type),
+			lb_debug_type(m, type->Array.elem),
+			subscripts, gb_count_of(subscripts));
+	}
 
 	case Type_EnumeratedArray: {
+		LLVMMetadataRef subscripts[1] = {};
+		subscripts[0] = LLVMDIBuilderGetOrCreateSubrange(m->debug_builder,
+			0ll,
+			type->EnumeratedArray.count
+		);
+
 		LLVMMetadataRef array_type = LLVMDIBuilderCreateArrayType(m->debug_builder,
-			type->EnumeratedArray.count, 8*cast(unsigned)type_align_of(type), lb_debug_type(m, type->EnumeratedArray.elem), nullptr, 0);
+			8*cast(uint64_t)type_size_of(type),
+			8*cast(unsigned)type_align_of(type),
+			lb_debug_type(m, type->EnumeratedArray.elem),
+			subscripts, gb_count_of(subscripts));
 		gbString name = type_to_string(type, temporary_allocator());
 		return LLVMDIBuilderCreateTypedef(m->debug_builder, array_type, name, gb_string_length(name), nullptr, 0, nullptr, cast(u32)(8*type_align_of(type)));
 	}
@@ -2187,7 +2269,7 @@ void lb_debug_complete_types(lbModule *m) {
 							8*type_size_of(bt)-word_bits + 1*word_bits,
 							LLVMDIFlagZero, lb_debug_type(m, t_int)
 						);
-						elements[3] = LLVMDIBuilderCreateMemberType(
+						elements[2] = LLVMDIBuilderCreateMemberType(
 							m->debug_builder, record_scope,
 							".allocator", 12,
 							file, 0,
@@ -2463,20 +2545,41 @@ lbValue lb_emit_string(lbProcedure *p, lbValue str_elem, lbValue str_len) {
 	}
 }
 
-LLVMAttributeRef lb_create_enum_attribute(LLVMContextRef ctx, char const *name, u64 value) {
+LLVMAttributeRef lb_create_enum_attribute_with_type(LLVMContextRef ctx, char const *name, LLVMTypeRef type) {
 	String s = make_string_c(name);
 
 	// NOTE(2021-02-25, bill); All this attributes require a type associated with them
 	// and the current LLVM C API does not expose this functionality yet.
 	// It is better to ignore the attributes for the time being
 	if (s == "byval") {
-		return nullptr;
+		// return nullptr;
 	} else if (s == "byref") {
 		return nullptr;
 	} else if (s == "preallocated") {
 		return nullptr;
 	} else if (s == "sret") {
-		return nullptr;
+		// return nullptr;
+	}
+
+	unsigned kind = LLVMGetEnumAttributeKindForName(name, s.len);
+	GB_ASSERT_MSG(kind != 0, "unknown attribute: %s", name);
+	return LLVMCreateEnumAttribute(ctx, kind, 0);
+}
+
+LLVMAttributeRef lb_create_enum_attribute(LLVMContextRef ctx, char const *name, u64 value) {
+	String s = make_string_c(name);
+
+	// NOTE(2021-02-25, bill); All this attributes require a type associated with them
+	// and the current LLVM C API does not expose this functionality yet.
+	// It is better to ignore the attributes for the time being
+	if (s == "byval") {
+		GB_PANIC("lb_create_enum_attribute_with_type should be used for %s", name);
+	} else if (s == "byref") {
+		GB_PANIC("lb_create_enum_attribute_with_type should be used for %s", name);
+	} else if (s == "preallocated") {
+		GB_PANIC("lb_create_enum_attribute_with_type should be used for %s", name);
+	} else if (s == "sret") {
+		GB_PANIC("lb_create_enum_attribute_with_type should be used for %s", name);
 	}
 
 	unsigned kind = LLVMGetEnumAttributeKindForName(name, s.len);
@@ -2514,10 +2617,18 @@ void lb_ensure_abi_function_type(lbModule *m, lbProcedure *p) {
 	GB_ASSERT(p->abi_function_type != nullptr);
 }
 
-lbProcedure *lb_create_procedure(lbModule *m, Entity *entity) {
+lbProcedure *lb_create_procedure(lbModule *m, Entity *entity, bool ignore_body) {
 	GB_ASSERT(entity != nullptr);
+	GB_ASSERT(entity->kind == Entity_Procedure);
+
+	String link_name = {};
 
-	String link_name = lb_get_entity_name(m, entity);
+	if (ignore_body) {
+		lbModule *other_module = lb_pkg_module(m->gen, entity->pkg);
+		link_name = lb_get_entity_name(other_module, entity);
+	} else {
+		link_name = lb_get_entity_name(m, entity);
+	}
 
 	{
 		StringHashKey key = string_hash_string(link_name);
@@ -2588,6 +2699,10 @@ lbProcedure *lb_create_procedure(lbModule *m, Entity *entity) {
 		lb_add_attribute_to_proc(m, p->value, "noreturn");
 	}
 
+	if (pt->Proc.calling_convention == ProcCC_Naked) {
+		lb_add_attribute_to_proc(m, p->value, "naked");
+	}
+
 	switch (p->inlining) {
 	case ProcInlining_inline:
 		lb_add_attribute_to_proc(m, p->value, "alwaysinline");
@@ -2681,6 +2796,11 @@ lbProcedure *lb_create_procedure(lbModule *m, Entity *entity) {
 		}
 	}
 
+	if (ignore_body) {
+		p->body = nullptr;
+		LLVMSetLinkage(p->value, LLVMExternalLinkage);
+	}
+
 
 	if (m->debug_builder) { // Debug Information
 		Type *bt = base_type(p->type);
@@ -2851,72 +2971,6 @@ Type *struct_type_from_systemv_distribute_struct_fields(Type *abi_type) {
 }
 
 
-lbValue lb_add_param(lbProcedure *p, Entity *e, Ast *expr, Type *abi_type, i32 index) {
-	lbParamPasskind kind = lbParamPass_Value;
-	lbValue v = lb_value_param(p, e, abi_type, index, &kind);
-	array_add(&p->params, v);
-
-	lbValue res = {};
-
-	switch (kind) {
-	case lbParamPass_Value: {
-		lbAddr l = lb_add_local(p, e->type, e, false, index);
-		lbValue x = v;
-		if (abi_type == t_llvm_bool) {
-			x = lb_emit_conv(p, x, t_bool);
-		}
-		lb_addr_store(p, l, x);
-		return x;
-	}
-	case lbParamPass_Pointer:
-		lb_add_entity(p->module, e, v);
-		return lb_emit_load(p, v);
-
-	case lbParamPass_Integer: {
-		lbAddr l = lb_add_local(p, e->type, e, false, index);
-		lbValue iptr = lb_emit_conv(p, l.addr, alloc_type_pointer(abi_type));
-		lb_emit_store(p, iptr, v);
-		return lb_addr_load(p, l);
-	}
-
-	case lbParamPass_ConstRef:
-		lb_add_entity(p->module, e, v);
-		return lb_emit_load(p, v);
-
-	case lbParamPass_BitCast: {
-		lbAddr l = lb_add_local(p, e->type, e, false, index);
-		lbValue x = lb_emit_transmute(p, v, e->type);
-		lb_addr_store(p, l, x);
-		return x;
-	}
-	case lbParamPass_Tuple: {
-		lbAddr l = lb_add_local(p, e->type, e, true, index);
-		Type *st = struct_type_from_systemv_distribute_struct_fields(abi_type);
-		lbValue ptr = lb_emit_transmute(p, l.addr, alloc_type_pointer(st));
-		if (abi_type->Tuple.variables.count > 0) {
-			array_pop(&p->params);
-		}
-		for_array(i, abi_type->Tuple.variables) {
-			Type *t = abi_type->Tuple.variables[i]->type;
-			GB_ASSERT(!is_type_tuple(t));
-
-			lbParamPasskind elem_kind = lbParamPass_Value;
-			lbValue elem = lb_value_param(p, nullptr, t, index+cast(i32)i, &elem_kind);
-			array_add(&p->params, elem);
-
-			lbValue dst = lb_emit_struct_ep(p, ptr, cast(i32)i);
-			lb_emit_store(p, dst, elem);
-		}
-		return lb_addr_load(p, l);
-	}
-
-	}
-
-
-	GB_PANIC("Unreachable");
-	return {};
-}
-
 void lb_start_block(lbProcedure *p, lbBlock *b) {
 	GB_ASSERT(b != nullptr);
 	if (!b->appended) {
@@ -3113,20 +3167,7 @@ void lb_begin_procedure_body(lbProcedure *p) {
 		}
 	}
 
-	if (p->tags != 0) {
-		u64 in = p->tags;
-		u64 out = p->module->state_flags;
-		if (in & ProcTag_bounds_check) {
-			out |= StateFlag_bounds_check;
-			out &= ~StateFlag_no_bounds_check;
-		} else if (in & ProcTag_no_bounds_check) {
-			out |= StateFlag_no_bounds_check;
-			out &= ~StateFlag_bounds_check;
-		}
-		p->module->state_flags = out;
-	}
-
-	p->builder = LLVMCreateBuilder();
+	p->builder = LLVMCreateBuilderInContext(p->module->ctx);
 
 	p->decl_block  = lb_create_block(p, "decls", true);
 	p->entry_block = lb_create_block(p, "entry", true);
@@ -3143,11 +3184,15 @@ void lb_begin_procedure_body(lbProcedure *p) {
 		lbValue return_ptr_value = {};
 		if (ft->ret.kind == lbArg_Indirect) {
 			// NOTE(bill): this must be parameter 0
+
+			String name = str_lit("agg.result");
+
 			Type *ptr_type = alloc_type_pointer(reduce_tuple_to_single_type(p->type->Proc.results));
-			Entity *e = alloc_entity_param(nullptr, make_token_ident(str_lit("agg.result")), ptr_type, false, false);
+			Entity *e = alloc_entity_param(nullptr, make_token_ident(name), ptr_type, false, false);
 			e->flags |= EntityFlag_Sret | EntityFlag_NoAlias;
 
 			return_ptr_value.value = LLVMGetParam(p->value, 0);
+			LLVMSetValueName2(return_ptr_value.value, cast(char const *)name.text, name.len);
 			return_ptr_value.type = ptr_type;
 			p->return_ptr = lb_addr(return_ptr_value);
 
@@ -3273,9 +3318,11 @@ void lb_end_procedure_body(lbProcedure *p) {
 	LLVMBuildBr(p->builder, p->entry_block->block);
 	LLVMPositionBuilderAtEnd(p->builder, p->curr_block->block);
 
+	LLVMValueRef instr = nullptr;
+
 	// Make sure there is a "ret void" at the end of a procedure with no return type
 	if (p->type->Proc.result_count == 0) {
-		LLVMValueRef instr = LLVMGetLastInstruction(p->curr_block->block);
+		instr = LLVMGetLastInstruction(p->curr_block->block);
 		if (!lb_is_instr_terminating(instr)) {
 			lb_emit_defer_stmts(p, lbDeferExit_Return, nullptr);
 			LLVMBuildRetVoid(p->builder);
@@ -3287,7 +3334,7 @@ void lb_end_procedure_body(lbProcedure *p) {
 
 	// Make sure every block terminates, and if not, make it unreachable
 	for (block = first_block; block != nullptr; block = LLVMGetNextBasicBlock(block)) {
-		LLVMValueRef instr = LLVMGetLastInstruction(block);
+		instr = LLVMGetLastInstruction(block);
 		if (instr == nullptr || !lb_is_instr_terminating(instr)) {
 			LLVMPositionBuilderAtEnd(p->builder, block);
 			LLVMBuildUnreachable(p->builder);
@@ -3295,7 +3342,7 @@ void lb_end_procedure_body(lbProcedure *p) {
 	}
 
 	p->curr_block = nullptr;
-	p->module->state_flags = 0;
+	p->state_flags = 0;
 }
 void lb_end_procedure(lbProcedure *p) {
 	LLVMDisposeBuilder(p->builder);
@@ -3362,6 +3409,20 @@ void lb_emit_if(lbProcedure *p, lbValue cond, lbBlock *true_block, lbBlock *fals
 	LLVMBuildCondBr(p->builder, cv, true_block->block, false_block->block);
 }
 
+bool lb_is_expr_untyped_const(Ast *expr) {
+	auto const &tv = type_and_value_of_expr(expr);
+	if (is_type_untyped(tv.type)) {
+		return tv.value.kind != ExactValue_Invalid;
+	}
+	return false;
+}
+
+lbValue lb_expr_untyped_const_to_typed(lbModule *m, Ast *expr, Type *t) {
+	GB_ASSERT(is_type_typed(t));
+	auto const &tv = type_and_value_of_expr(expr);
+	return lb_const_value(m, t, tv.value);
+}
+
 lbValue lb_build_cond(lbProcedure *p, Ast *cond, lbBlock *true_block, lbBlock *false_block) {
 	GB_ASSERT(cond != nullptr);
 	GB_ASSERT(true_block  != nullptr);
@@ -3393,8 +3454,13 @@ lbValue lb_build_cond(lbProcedure *p, Ast *cond, lbBlock *true_block, lbBlock *f
 	case_end;
 	}
 
-	lbValue v = lb_build_expr(p, cond);
-	// v = lb_emit_conv(p, v, t_bool);
+	lbValue v = {};
+	if (lb_is_expr_untyped_const(cond)) {
+		v = lb_expr_untyped_const_to_typed(p->module, cond, t_llvm_bool);
+	} else {
+		v = lb_build_expr(p, cond);
+	}
+
 	v = lb_emit_conv(p, v, t_llvm_bool);
 
 	lb_emit_if(p, v, true_block, false_block);
@@ -3419,6 +3485,21 @@ lbAddr lb_add_local(lbProcedure *p, Type *type, Entity *e, bool zero_init, i32 p
 	LLVMSetAlignment(ptr, alignment);
 
 	LLVMPositionBuilderAtEnd(p->builder, p->curr_block->block);
+
+
+	if (!zero_init) {
+		// If there is any padding of any kind, just zero init regardless of zero_init parameter
+		LLVMTypeKind kind = LLVMGetTypeKind(llvm_type);
+		if (kind == LLVMStructTypeKind) {
+			i64 sz = type_size_of(type);
+			if (type_size_of_struct_pretend_is_packed(type) != sz) {
+				zero_init = true;
+			}
+		} else if (kind == LLVMArrayTypeKind) {
+			zero_init = true;
+		}
+	}
+
 	if (zero_init) {
 		LLVMTypeKind kind = LLVMGetTypeKind(llvm_type);
 
@@ -3544,16 +3625,14 @@ void lb_build_constant_value_decl(lbProcedure *p, AstValueDecl *vd) {
 		Ast *ident = vd->names[i];
 		GB_ASSERT(ident->kind == Ast_Ident);
 		Entity *e = entity_of_node(ident);
-		if (e == nullptr) {
-			continue;
-		}
+		GB_ASSERT(e != nullptr);
 		if (e->kind != Entity_TypeName) {
 			continue;
 		}
 
 		bool polymorphic_struct = false;
 		if (e->type != nullptr && e->kind == Entity_TypeName) {
-		Type *bt = base_type(e->type);
+			Type *bt = base_type(e->type);
 			if (bt->kind == Type_Struct) {
 				polymorphic_struct = bt->Struct.is_polymorphic;
 			}
@@ -3575,12 +3654,16 @@ void lb_build_constant_value_decl(lbProcedure *p, AstValueDecl *vd) {
 		Ast *ident = vd->names[i];
 		GB_ASSERT(ident->kind == Ast_Ident);
 		Entity *e = entity_of_node(ident);
-		if (e == nullptr) {
-			continue;
-		}
+		GB_ASSERT(e != nullptr);
 		if (e->kind != Entity_Procedure) {
 			continue;
 		}
+		GB_ASSERT (vd->values[i] != nullptr);
+
+		Ast *value = unparen_expr(vd->values[i]);
+		if (value->kind != Ast_ProcLit) {
+			continue; // It's an alias
+		}
 
 		CheckerInfo *info = p->module->info;
 		DeclInfo *decl = decl_info_of_entity(e);
@@ -3948,63 +4031,105 @@ void lb_build_range_string(lbProcedure *p, lbValue expr, Type *val_type,
 }
 
 
-void lb_build_range_interval(lbProcedure *p, AstBinaryExpr *node, Type *val_type,
-                             lbValue *val_, lbValue *idx_, lbBlock **loop_, lbBlock **done_) {
+void lb_build_range_interval(lbProcedure *p, AstBinaryExpr *node,
+                             AstRangeStmt *rs, Scope *scope) {
+	bool ADD_EXTRA_WRAPPING_CHECK = true;
+
 	lbModule *m = p->module;
 
-	// TODO(bill): How should the behaviour work for lower and upper bounds checking for iteration?
-	// If 'lower' is changed, should 'val' do so or is that not typical behaviour?
+	lb_open_scope(p, scope);
 
-	lbValue lower = lb_build_expr(p, node->left);
-	lbValue upper = {};
+	Type *val0_type = nullptr;
+	Type *val1_type = nullptr;
+	if (rs->vals.count > 0 && rs->vals[0] != nullptr && !is_blank_ident(rs->vals[0])) {
+		val0_type = type_of_expr(rs->vals[0]);
+	}
+	if (rs->vals.count > 1 && rs->vals[1] != nullptr && !is_blank_ident(rs->vals[1])) {
+		val1_type = type_of_expr(rs->vals[1]);
+	}
 
-	lbValue val = {};
-	lbValue idx = {};
-	lbBlock *loop = nullptr;
-	lbBlock *done = nullptr;
-	lbBlock *body = nullptr;
+	if (val0_type != nullptr) {
+		Entity *e = entity_of_node(rs->vals[0]);
+		lb_add_local(p, e->type, e, true);
+	}
+	if (val1_type != nullptr) {
+		Entity *e = entity_of_node(rs->vals[1]);
+		lb_add_local(p, e->type, e, true);
+	}
 
-	if (val_type == nullptr) {
-		val_type = lower.type;
+	TokenKind op = Token_Lt;
+	switch (node->op.kind) {
+	case Token_Ellipsis:  op = Token_LtEq; break;
+	case Token_RangeFull: op = Token_LtEq; break;
+	case Token_RangeHalf: op = Token_Lt;  break;
+	default: GB_PANIC("Invalid interval operator"); break;
 	}
-	lbAddr value = lb_add_local_generated(p, val_type, false);
+
+	lbValue lower = lb_build_expr(p, node->left);
+	lbValue upper = {}; // initialized each time in the loop
+
+	lbAddr value = lb_add_local_generated(p, val0_type ? val0_type : lower.type, false);
 	lb_addr_store(p, value, lower);
 
 	lbAddr index = lb_add_local_generated(p, t_int, false);
 	lb_addr_store(p, index, lb_const_int(m, t_int, 0));
 
-	loop = lb_create_block(p, "for.interval.loop");
+	lbBlock *loop = lb_create_block(p, "for.interval.loop");
+	lbBlock *body = lb_create_block(p, "for.interval.body");
+	lbBlock *done = lb_create_block(p, "for.interval.done");
+
 	lb_emit_jump(p, loop);
 	lb_start_block(p, loop);
 
-	body = lb_create_block(p, "for.interval.body");
-	done = lb_create_block(p, "for.interval.done");
-
-
-	TokenKind op = Token_Lt;
-	switch (node->op.kind) {
-	case Token_Ellipsis:  op = Token_LtEq; break;
-	case Token_RangeHalf: op = Token_Lt;  break;
-	default: GB_PANIC("Invalid interval operator"); break;
-	}
-
 	upper = lb_build_expr(p, node->right);
-
 	lbValue curr_value = lb_addr_load(p, value);
 	lbValue cond = lb_emit_comp(p, op, curr_value, upper);
 	lb_emit_if(p, cond, body, done);
 	lb_start_block(p, body);
 
-	val = lb_addr_load(p, value);
-	idx = lb_addr_load(p, index);
+	lbValue val = lb_addr_load(p, value);
+	lbValue idx = lb_addr_load(p, index);
+	if (val0_type) lb_store_range_stmt_val(p, rs->vals[0], val);
+	if (val1_type) lb_store_range_stmt_val(p, rs->vals[1], idx);
 
-	lb_emit_increment(p, value.addr);
-	lb_emit_increment(p, index.addr);
+	{
+		// NOTE: this check block will most likely be optimized out, and is here
+		// to make this code easier to read
+		lbBlock *check = nullptr;
+		lbBlock *post = lb_create_block(p, "for.interval.post");
 
-	if (val_)  *val_  = val;
-	if (idx_)  *idx_  = idx;
-	if (loop_) *loop_ = loop;
-	if (done_) *done_ = done;
+		lbBlock *continue_block = post;
+
+		if (ADD_EXTRA_WRAPPING_CHECK &&
+		    op == Token_LtEq) {
+			check = lb_create_block(p, "for.interval.check");
+			continue_block = check;
+		}
+
+		lb_push_target_list(p, rs->label, done, continue_block, nullptr);
+
+		lb_build_stmt(p, rs->body);
+
+		lb_close_scope(p, lbDeferExit_Default, nullptr);
+		lb_pop_target_list(p);
+
+		if (check != nullptr) {
+			lb_emit_jump(p, check);
+			lb_start_block(p, check);
+
+			lbValue check_cond = lb_emit_comp(p, Token_NotEq, curr_value, upper);
+			lb_emit_if(p, check_cond, post, done);
+		} else {
+			lb_emit_jump(p, post);
+		}
+
+		lb_start_block(p, post);
+		lb_emit_increment(p, value.addr);
+		lb_emit_increment(p, index.addr);
+		lb_emit_jump(p, loop);
+	}
+
+	lb_start_block(p, done);
 }
 
 void lb_build_range_enum(lbProcedure *p, Type *enum_type, Type *val_type, lbValue *val_, lbValue *idx_, lbBlock **loop_, lbBlock **done_) {
@@ -4159,6 +4284,11 @@ void lb_build_range_stmt_struct_soa(lbProcedure *p, AstRangeStmt *rs, Scope *sco
 void lb_build_range_stmt(lbProcedure *p, AstRangeStmt *rs, Scope *scope) {
 	Ast *expr = unparen_expr(rs->expr);
 
+	if (is_ast_range(expr)) {
+		lb_build_range_interval(p, &expr->BinaryExpr, rs, scope);
+		return;
+	}
+
 	Type *expr_type = type_of_expr(expr);
 	if (expr_type != nullptr) {
 		Type *et = base_type(type_deref(expr_type));
@@ -4195,10 +4325,7 @@ void lb_build_range_stmt(lbProcedure *p, AstRangeStmt *rs, Scope *scope) {
 	bool is_map = false;
 	TypeAndValue tav = type_and_value_of_expr(expr);
 
-
-	if (is_ast_range(expr)) {
-		lb_build_range_interval(p, &expr->BinaryExpr, val0_type, &val, &key, &loop, &done);
-	} else if (tav.mode == Addressing_Type) {
+	if (tav.mode == Addressing_Type) {
 		lb_build_range_enum(p, type_deref(tav.type), val0_type, &val, &key, &loop, &done);
 	} else {
 		Type *expr_type = type_of_expr(expr);
@@ -4347,7 +4474,7 @@ void lb_build_inline_range_stmt(lbProcedure *p, AstUnrollRangeStmt *rs, Scope *s
 
 		ExactValue start = start_expr->tav.value;
 		ExactValue end   = end_expr->tav.value;
-		if (op == Token_Ellipsis) { // .. [start, end]
+		if (op != Token_RangeHalf) { // .. [start, end] (or ..=)
 			ExactValue index = exact_value_i64(0);
 			for (ExactValue val = start;
 			     compare_exact_values(Token_LtEq, val, end);
@@ -4358,7 +4485,7 @@ void lb_build_inline_range_stmt(lbProcedure *p, AstUnrollRangeStmt *rs, Scope *s
 
 				lb_build_stmt(p, rs->body);
 			}
-		} else if (op == Token_RangeHalf) { // ..< [start, end)
+		} else { // ..< [start, end)
 			ExactValue index = exact_value_i64(0);
 			for (ExactValue val = start;
 			     compare_exact_values(Token_Lt, val, end);
@@ -4525,6 +4652,7 @@ void lb_build_switch_stmt(lbProcedure *p, AstSwitchStmt *ss, Scope *scope) {
 				TokenKind op = Token_Invalid;
 				switch (ie->op.kind) {
 				case Token_Ellipsis:  op = Token_LtEq; break;
+				case Token_RangeFull: op = Token_LtEq; break;
 				case Token_RangeHalf: op = Token_Lt;   break;
 				default: GB_PANIC("Invalid interval operator"); break;
 				}
@@ -4763,6 +4891,9 @@ lbValue lb_emit_logical_binary_expr(lbProcedure *p, TokenKind op, Ast *left, Ast
 
 	if (done->preds.count == 0) {
 		lb_start_block(p, rhs);
+		if (lb_is_expr_untyped_const(right)) {
+			return lb_expr_untyped_const_to_typed(m, right, type);
+		}
 		return lb_build_expr(p, right);
 	}
 
@@ -4777,7 +4908,12 @@ lbValue lb_emit_logical_binary_expr(lbProcedure *p, TokenKind op, Ast *left, Ast
 	}
 
 	lb_start_block(p, rhs);
-	lbValue edge = lb_build_expr(p, right);
+	lbValue edge = {};
+	if (lb_is_expr_untyped_const(right)) {
+		edge = lb_expr_untyped_const_to_typed(m, right, type);
+	} else {
+		edge = lb_build_expr(p, right);
+	}
 
 	incoming_values[done->preds.count] = edge.value;
 	incoming_blocks[done->preds.count] = p->curr_block->block;
@@ -4815,12 +4951,12 @@ void lb_build_stmt(lbProcedure *p, Ast *node) {
 		LLVMSetCurrentDebugLocation2(p->builder, prev_debug_location);
 	});
 
-	u64 prev_state_flags = p->module->state_flags;
-	defer (p->module->state_flags = prev_state_flags);
+	u16 prev_state_flags = p->state_flags;
+	defer (p->state_flags = prev_state_flags);
 
 	if (node->state_flags != 0) {
-		u64 in = node->state_flags;
-		u64 out = p->module->state_flags;
+		u16 in = node->state_flags;
+		u16 out = p->state_flags;
 
 		if (in & StateFlag_bounds_check) {
 			out |= StateFlag_bounds_check;
@@ -4830,7 +4966,7 @@ void lb_build_stmt(lbProcedure *p, Ast *node) {
 			out &= ~StateFlag_bounds_check;
 		}
 
-		p->module->state_flags = out;
+		p->state_flags = out;
 	}
 
 	switch (node->kind) {
@@ -5412,6 +5548,7 @@ lbValue lb_emit_min(lbProcedure *p, Type *t, lbValue x, lbValue y) {
 		args[0] = x;
 		args[1] = y;
 		switch (sz) {
+		case 16: return lb_emit_runtime_call(p, "min_f16", args);
 		case 32: return lb_emit_runtime_call(p, "min_f32", args);
 		case 64: return lb_emit_runtime_call(p, "min_f64", args);
 		}
@@ -5429,6 +5566,7 @@ lbValue lb_emit_max(lbProcedure *p, Type *t, lbValue x, lbValue y) {
 		args[0] = x;
 		args[1] = y;
 		switch (sz) {
+		case 16: return lb_emit_runtime_call(p, "max_f16", args);
 		case 32: return lb_emit_runtime_call(p, "max_f32", args);
 		case 64: return lb_emit_runtime_call(p, "max_f64", args);
 		}
@@ -5462,9 +5600,10 @@ LLVMValueRef lb_find_or_add_entity_string_ptr(lbModule *m, String const &str) {
 
 		isize max_len = 7+8+1;
 		char *name = gb_alloc_array(permanent_allocator(), char, max_len);
-		isize len = gb_snprintf(name, max_len, "csbs$%x", m->global_array_index);
+
+		u32 id = cast(u32)gb_atomic32_fetch_add(&m->gen->global_array_index, 1);
+		isize len = gb_snprintf(name, max_len, "csbs$%x", id);
 		len -= 1;
-		m->global_array_index++;
 
 		LLVMValueRef global_data = LLVMAddGlobal(m->mod, LLVMTypeOf(data), name);
 		LLVMSetInitializer(global_data, data);
@@ -5504,9 +5643,9 @@ lbValue lb_find_or_add_entity_string_byte_slice(lbModule *m, String const &str)
 	{
 		isize max_len = 7+8+1;
 		name = gb_alloc_array(permanent_allocator(), char, max_len);
-		isize len = gb_snprintf(name, max_len, "csbs$%x", m->global_array_index);
+		u32 id = cast(u32)gb_atomic32_fetch_add(&m->gen->global_array_index, 1);
+		isize len = gb_snprintf(name, max_len, "csbs$%x", id);
 		len -= 1;
-		m->global_array_index++;
 	}
 	LLVMValueRef global_data = LLVMAddGlobal(m->mod, LLVMTypeOf(data), name);
 	LLVMSetInitializer(global_data, data);
@@ -5628,7 +5767,7 @@ lbValue lb_type_info(lbModule *m, Type *type) {
 	};
 
 	lbValue value = {};
-	value.value = LLVMConstGEP(lb_global_type_info_data.addr.value, indices, gb_count_of(indices));
+	value.value = LLVMConstGEP(lb_global_type_info_data_ptr(m).value, indices, gb_count_of(indices));
 	value.type = t_type_info_ptr;
 	return value;
 }
@@ -5661,6 +5800,112 @@ LLVMValueRef lb_build_constant_array_values(lbModule *m, Type *type, Type *elem_
 	return llvm_const_array(lb_type(m, elem_type), values, cast(unsigned int)count);
 }
 
+lbValue lb_find_procedure_value_from_entity(lbModule *m, Entity *e) {
+	GB_ASSERT(is_type_proc(e->type));
+	e = strip_entity_wrapping(e);
+	GB_ASSERT(e != nullptr);
+	auto *found = map_get(&m->values, hash_entity(e));
+	if (found) {
+		return *found;
+	}
+
+	bool ignore_body = false;
+
+	if (USE_SEPARTE_MODULES) {
+		lbModule *other_module = lb_pkg_module(m->gen, e->pkg);
+		ignore_body = other_module != m;
+	}
+
+	lbProcedure *missing_proc = lb_create_procedure(m, e, ignore_body);
+	found = map_get(&m->values, hash_entity(e));
+	if (found) {
+		return *found;
+	}
+
+	GB_PANIC("Error in: %s, missing procedure %.*s\n", token_pos_to_string(e->token.pos), LIT(e->token.string));
+	return {};
+}
+
+lbValue lb_find_value_from_entity(lbModule *m, Entity *e) {
+	e = strip_entity_wrapping(e);
+	GB_ASSERT(e != nullptr);
+
+	GB_ASSERT(e->token.string != "_");
+
+	if (e->kind == Entity_Procedure) {
+		return lb_find_procedure_value_from_entity(m, e);
+	}
+
+	auto *found = map_get(&m->values, hash_entity(e));
+	if (found) {
+		return *found;
+	}
+
+	if (USE_SEPARTE_MODULES) {
+		lbModule *other_module = lb_pkg_module(m->gen, e->pkg);
+
+		// TODO(bill): correct this logic
+		bool is_external = other_module != m;
+		if (!is_external) {
+			if (e->code_gen_module != nullptr) {
+				other_module = e->code_gen_module;
+			} else {
+				other_module = nullptr;
+			}
+			is_external = other_module != m;
+		}
+
+		if (is_external) {
+			String name = lb_get_entity_name(other_module, e);
+
+			lbValue g = {};
+			g.value = LLVMAddGlobal(m->mod, lb_type(m, e->type), alloc_cstring(permanent_allocator(), name));
+			g.type = alloc_type_pointer(e->type);
+			lb_add_entity(m, e, g);
+			lb_add_member(m, name, g);
+
+			LLVMSetLinkage(g.value, LLVMExternalLinkage);
+
+			// if (other_module != nullptr) {
+			// 	lbValue *other_found = string_map_get(&other_module->members, name);
+			// 	if (other_found) {
+			// 		lbValue other_g = *other_found;
+			// 	}
+			// }
+
+			// LLVMSetLinkage(other_g.value, LLVMExternalLinkage);
+
+			if (e->Variable.thread_local_model != "") {
+				LLVMSetThreadLocal(g.value, true);
+
+				String m = e->Variable.thread_local_model;
+				LLVMThreadLocalMode mode = LLVMGeneralDynamicTLSModel;
+				if (m == "default") {
+					mode = LLVMGeneralDynamicTLSModel;
+				} else if (m == "localdynamic") {
+					mode = LLVMLocalDynamicTLSModel;
+				} else if (m == "initialexec") {
+					mode = LLVMInitialExecTLSModel;
+				} else if (m == "localexec") {
+					mode = LLVMLocalExecTLSModel;
+				} else {
+					GB_PANIC("Unhandled thread local mode %.*s", LIT(m));
+				}
+				LLVMSetThreadLocalMode(g.value, mode);
+			}
+
+
+			return g;
+		}
+	}
+
+	GB_PANIC("\n\tError in: %s, missing value %.*s\n", token_pos_to_string(e->token.pos), LIT(e->token.string));
+	return {};
+}
+
+
+
+
 
 lbValue lb_const_value(lbModule *m, Type *type, ExactValue value, bool allow_local) {
 	LLVMContextRef ctx = m->ctx;
@@ -5687,14 +5932,7 @@ lbValue lb_const_value(lbModule *m, Type *type, ExactValue value, bool allow_loc
 			return lb_generate_anonymous_proc_lit(m, str_lit("_proclit"), expr);
 		}
 		Entity *e = entity_from_expr(expr);
-		e = strip_entity_wrapping(e);
-		GB_ASSERT(e != nullptr);
-		auto *found = map_get(&m->values, hash_entity(e));
-		if (found) {
-			return *found;
-		}
-
-		GB_PANIC("Error in: %s, missing procedure %.*s\n", token_pos_to_string(e->token.pos), LIT(e->token.string));
+		return lb_find_procedure_value_from_entity(m, e);
 	}
 
 	bool is_local = allow_local && m->curr_procedure != nullptr;
@@ -5743,8 +5981,8 @@ lbValue lb_const_value(lbModule *m, Type *type, ExactValue value, bool allow_loc
 			} else {
 				isize max_len = 7+8+1;
 				char *str = gb_alloc_array(permanent_allocator(), char, max_len);
-				isize len = gb_snprintf(str, max_len, "csba$%x", m->global_array_index);
-				m->global_array_index++;
+				u32 id = cast(u32)gb_atomic32_fetch_add(&m->gen->global_array_index, 1);
+				isize len = gb_snprintf(str, max_len, "csba$%x", id);
 
 				String name = make_string(cast(u8 *)str, len-1);
 
@@ -5797,7 +6035,7 @@ lbValue lb_const_value(lbModule *m, Type *type, ExactValue value, bool allow_loc
 			res.value = llvm_const_array(et, elems, cast(unsigned)count);
 			return res;
 		}
-		GB_PANIC("HERE!\n");
+		GB_PANIC("This should not have happened!\n");
 
 		LLVMValueRef data = LLVMConstStringInContext(ctx,
 			cast(char const *)value.value_string.text,
@@ -6799,15 +7037,29 @@ lbValue lb_build_binary_expr(lbProcedure *p, Ast *expr) {
 	case Token_And:
 	case Token_Or:
 	case Token_Xor:
-	case Token_AndNot:
-	case Token_Shl:
-	case Token_Shr: {
+	case Token_AndNot: {
 		Type *type = default_type(tv.type);
 		lbValue left = lb_build_expr(p, be->left);
 		lbValue right = lb_build_expr(p, be->right);
 		return lb_emit_arith(p, be->op.kind, left, right, type);
 	}
 
+	case Token_Shl:
+	case Token_Shr: {
+		lbValue left, right;
+		Type *type = default_type(tv.type);
+		left = lb_build_expr(p, be->left);
+
+		if (lb_is_expr_untyped_const(be->right)) {
+			// NOTE(bill): RHS shift operands can still be untyped
+			// Just bypass the standard lb_build_expr
+			right = lb_expr_untyped_const_to_typed(p->module, be->right, type);
+		} else {
+			right = lb_build_expr(p, be->right);
+		}
+		return lb_emit_arith(p, be->op.kind, left, right, type);
+	}
+
 	case Token_CmpEq:
 	case Token_NotEq:
 	case Token_Lt:
@@ -7598,10 +7850,13 @@ lbContextData *lb_push_context_onto_stack_from_implicit_parameter(lbProcedure *p
 	GB_ASSERT(pt->kind == Type_Proc);
 	GB_ASSERT(pt->Proc.calling_convention == ProcCC_Odin);
 
-	Entity *e = alloc_entity_param(nullptr, make_token_ident(str_lit("__.context_ptr")), t_context_ptr, false, false);
+	String name = str_lit("__.context_ptr");
+
+	Entity *e = alloc_entity_param(nullptr, make_token_ident(name), t_context_ptr, false, false);
 	e->flags |= EntityFlag_NoAlias;
 
 	LLVMValueRef context_ptr = LLVMGetParam(p->value, LLVMCountParams(p->value)-1);
+	LLVMSetValueName2(context_ptr, cast(char const *)name.text, name.len);
 	context_ptr = LLVMBuildPointerCast(p->builder, context_ptr, lb_type(p->module, e->type), "");
 
 	lbValue param = {context_ptr, e->type};
@@ -8084,6 +8339,8 @@ Array<lbValue> lb_value_to_array(lbProcedure *p, lbValue value) {
 
 
 lbValue lb_emit_call_internal(lbProcedure *p, lbValue value, lbValue return_ptr, Array<lbValue> const &processed_args, Type *abi_rt, lbAddr context_ptr, ProcInlining inlining) {
+	GB_ASSERT(p->module->ctx == LLVMGetTypeContext(LLVMTypeOf(value.value)));
+
 	unsigned arg_count = cast(unsigned)processed_args.count;
 	if (return_ptr.value != nullptr) {
 		arg_count += 1;
@@ -8158,31 +8415,18 @@ lbValue lb_emit_call_internal(lbProcedure *p, lbValue value, lbValue return_ptr,
 	}
 }
 
-lbValue lb_emit_runtime_call(lbProcedure *p, char const *c_name, Array<lbValue> const &args) {
-	// LLVMMetadataRef curr_loc = LLVMGetCurrentDebugLocation2(p->builder);
-	// LLVMSetCurrentDebugLocation2(p->builder, nullptr);
-	// defer (if (curr_loc) {
-	// 	LLVMSetCurrentDebugLocation2(p->builder, curr_loc);
-	// });
-
-	String name = make_string_c(c_name);
-
 
-	AstPackage *pkg = p->module->info->runtime_package;
+lbValue lb_lookup_runtime_procedure(lbModule *m, String const &name) {
+	AstPackage *pkg = m->info->runtime_package;
 	Entity *e = scope_lookup_current(pkg->scope, name);
+	return lb_find_procedure_value_from_entity(m, e);
+}
 
-	lbValue *found = nullptr;
-	if (p->module != e->code_gen_module) {
-		gb_mutex_lock(&p->module->mutex);
-	}
-	GB_ASSERT(e->code_gen_module != nullptr);
-	found = map_get(&e->code_gen_module->values, hash_entity(e));
-	if (p->module != e->code_gen_module) {
-		gb_mutex_unlock(&p->module->mutex);
-	}
 
-	GB_ASSERT_MSG(found != nullptr, "%s", c_name);
-	return lb_emit_call(p, *found, args);
+lbValue lb_emit_runtime_call(lbProcedure *p, char const *c_name, Array<lbValue> const &args) {
+	String name = make_string_c(c_name);
+	lbValue proc = lb_lookup_runtime_procedure(p->module, name);
+	return lb_emit_call(p, proc, args);
 }
 
 lbValue lb_emit_call(lbProcedure *p, lbValue value, Array<lbValue> const &args, ProcInlining inlining, bool use_return_ptr_hint) {
@@ -8321,9 +8565,7 @@ lbValue lb_emit_call(lbProcedure *p, lbValue value, Array<lbValue> const &args,
 		if (e != nullptr && entity_has_deferred_procedure(e)) {
 			DeferredProcedureKind kind = e->Procedure.deferred_procedure.kind;
 			Entity *deferred_entity = e->Procedure.deferred_procedure.entity;
-			lbValue *deferred_found = map_get(&p->module->values, hash_entity(deferred_entity));
-			GB_ASSERT(deferred_found != nullptr);
-			lbValue deferred = *deferred_found;
+			lbValue deferred = lb_find_procedure_value_from_entity(p->module, deferred_entity);
 
 
 			auto in_args = args;
@@ -8645,7 +8887,7 @@ lbValue lb_build_builtin_proc(lbProcedure *p, Ast *expr, TypeAndValue const &tv,
 	switch (id) {
 	case BuiltinProc_DIRECTIVE: {
 		ast_node(bd, BasicDirective, ce->proc);
-		String name = bd->name;
+		String name = bd->name.string;
 		GB_ASSERT(name == "location");
 		String procedure = p->entity->token.string;
 		TokenPos pos = ast_token(ce->proc).pos;
@@ -9134,9 +9376,11 @@ lbValue lb_build_builtin_proc(lbProcedure *p, Ast *expr, TypeAndValue const &tv,
 	case BuiltinProc_overflow_sub:
 	case BuiltinProc_overflow_mul:
 		{
-			Type *tuple = tv.type;
-			GB_ASSERT(is_type_tuple(tuple));
-			Type *type = tuple->Tuple.variables[0]->type;
+			Type *main_type = tv.type;
+			Type *type = main_type;
+			if (is_type_tuple(main_type)) {
+				type = main_type->Tuple.variables[0]->type;
+			}
 
 			lbValue x = lb_build_expr(p, ce->args[0]);
 			lbValue y = lb_build_expr(p, ce->args[1]);
@@ -9166,21 +9410,85 @@ lbValue lb_build_builtin_proc(lbProcedure *p, Ast *expr, TypeAndValue const &tv,
 			args[0] = x.value;
 			args[1] = y.value;
 
-			Type *res_type = nullptr;
-			{
+			lbValue res = {};
+			res.value = LLVMBuildCall(p->builder, ip, args, gb_count_of(args), "");
+
+			if (is_type_tuple(main_type)) {
+				Type *res_type = nullptr;
 				gbAllocator a = permanent_allocator();
 				res_type = alloc_type_tuple();
 				array_init(&res_type->Tuple.variables, a, 2);
 				res_type->Tuple.variables[0] = alloc_entity_field(nullptr, blank_token, type,        false, 0);
 				res_type->Tuple.variables[1] = alloc_entity_field(nullptr, blank_token, t_llvm_bool, false, 1);
+
+				res.type = res_type;
+			} else {
+				res.value = LLVMBuildExtractValue(p->builder, res.value, 0, "");
+				res.type = type;
 			}
+			return res;
+		}
+
+	case BuiltinProc_sqrt:
+		{
+			Type *type = tv.type;
+
+			lbValue x = lb_build_expr(p, ce->args[0]);
+			x = lb_emit_conv(p, x, type);
+
+			char const *name = "llvm.sqrt";
+			LLVMTypeRef types[1] = {lb_type(p->module, type)};
+			unsigned id = LLVMLookupIntrinsicID(name, gb_strlen(name));
+			GB_ASSERT_MSG(id != 0, "Unable to find %s.%s", name, LLVMPrintTypeToString(types[0]));
+			LLVMValueRef ip = LLVMGetIntrinsicDeclaration(p->module->mod, id, types, gb_count_of(types));
+
+			LLVMValueRef args[1] = {};
+			args[0] = x.value;
 
 			lbValue res = {};
 			res.value = LLVMBuildCall(p->builder, ip, args, gb_count_of(args), "");
-			res.type = res_type;
+			res.type = type;
 			return res;
 		}
 
+	case BuiltinProc_mem_copy:
+	case BuiltinProc_mem_copy_non_overlapping:
+		{
+
+
+			lbValue dst = lb_build_expr(p, ce->args[0]);
+			lbValue src = lb_build_expr(p, ce->args[1]);
+			lbValue len = lb_build_expr(p, ce->args[2]);
+			dst = lb_emit_conv(p, dst, t_rawptr);
+			src = lb_emit_conv(p, src, t_rawptr);
+			len = lb_emit_conv(p, len, t_int);
+
+			char const *name = nullptr;
+			switch (id) {
+			case BuiltinProc_mem_copy:                 name = "llvm.memmove"; break;
+			case BuiltinProc_mem_copy_non_overlapping: name = "llvm.memcpy";  break;
+			}
+
+			LLVMTypeRef types[3] = {
+				lb_type(p->module, t_rawptr),
+				lb_type(p->module, t_rawptr),
+				lb_type(p->module, t_int)
+			};
+			unsigned id = LLVMLookupIntrinsicID(name, gb_strlen(name));
+			GB_ASSERT_MSG(id != 0, "Unable to find %s.%s.%s.%s", name, LLVMPrintTypeToString(types[0]), LLVMPrintTypeToString(types[1]), LLVMPrintTypeToString(types[2]));
+			LLVMValueRef ip = LLVMGetIntrinsicDeclaration(p->module->mod, id, types, gb_count_of(types));
+
+			LLVMValueRef args[4] = {};
+			args[0] = dst.value;
+			args[1] = src.value;
+			args[2] = len.value;
+			args[3] = LLVMConstInt(LLVMInt1TypeInContext(p->module->ctx), 0, false); // is_volatile parameter
+
+			LLVMBuildCall(p->builder, ip, args, gb_count_of(args), "");
+
+			return {};
+		}
+
 
 	case BuiltinProc_atomic_fence:
 		LLVMBuildFence(p->builder, LLVMAtomicOrderingSequentiallyConsistent, false, "");
@@ -9390,16 +9698,22 @@ lbValue lb_build_builtin_proc(lbProcedure *p, Ast *expr, TypeAndValue const &tv,
 			single_threaded
 		);
 
-		GB_ASSERT(tv.type->kind == Type_Tuple);
-		Type *fix_typed = alloc_type_tuple();
-		array_init(&fix_typed->Tuple.variables, permanent_allocator(), 2);
-		fix_typed->Tuple.variables[0] = tv.type->Tuple.variables[0];
-		fix_typed->Tuple.variables[1] = alloc_entity_field(nullptr, blank_token, t_llvm_bool, false, 1);
+		if (tv.type->kind == Type_Tuple) {
+			Type *fix_typed = alloc_type_tuple();
+			array_init(&fix_typed->Tuple.variables, permanent_allocator(), 2);
+			fix_typed->Tuple.variables[0] = tv.type->Tuple.variables[0];
+			fix_typed->Tuple.variables[1] = alloc_entity_field(nullptr, blank_token, t_llvm_bool, false, 1);
 
-		lbValue res = {};
-		res.value = value;
-		res.type = fix_typed;
-		return res;
+			lbValue res = {};
+			res.value = value;
+			res.type = fix_typed;
+			return res;
+		} else {
+			lbValue res = {};
+			res.value = LLVMBuildExtractValue(p->builder, value, 0, "");
+			res.type = tv.type;
+			return res;
+		}
 	}
 
 
@@ -9490,7 +9804,8 @@ lbValue lb_handle_param_value(lbProcedure *p, Type *parameter_type, ParameterVal
 	switch (param_value.kind) {
 	case ParameterValue_Constant:
 		if (is_type_constant_type(parameter_type)) {
-			return lb_const_value(p->module, parameter_type, param_value.value);
+			auto res = lb_const_value(p->module, parameter_type, param_value.value);
+			return res;
 		} else {
 			ExactValue ev = param_value.value;
 			lbValue arg = {};
@@ -9900,24 +10215,6 @@ void lb_emit_increment(lbProcedure *p, lbValue addr) {
 
 }
 
-LLVMValueRef lb_lookup_runtime_procedure(lbModule *m, String const &name) {
-	AstPackage *pkg = m->info->runtime_package;
-	Entity *e = scope_lookup_current(pkg->scope, name);
-
-	lbValue *found = nullptr;
-	if (m != e->code_gen_module) {
-		gb_mutex_lock(&m->mutex);
-	}
-	GB_ASSERT(e->code_gen_module != nullptr);
-	found = map_get(&e->code_gen_module->values, hash_entity(e));
-	if (m != e->code_gen_module) {
-		gb_mutex_unlock(&m->mutex);
-	}
-	GB_ASSERT(found != nullptr);
-
-	return found->value;
-}
-
 lbValue lb_emit_byte_swap(lbProcedure *p, lbValue value, Type *end_type) {
 	GB_ASSERT(type_size_of(value.type) == type_size_of(end_type));
 
@@ -10242,7 +10539,7 @@ lbValue lb_get_equal_proc_for_type(lbModule *m, Type *type) {
 
 	lb_start_block(p, block_diff_ptr);
 
-	if (type->kind == Type_Struct)  {
+	if (type->kind == Type_Struct) {
 		type_set_offsets(type);
 
 		lbBlock *block_false = lb_create_block(p, "bfalse");
@@ -10268,6 +10565,56 @@ lbValue lb_get_equal_proc_for_type(lbModule *m, Type *type) {
 		lb_start_block(p, block_false);
 
 		LLVMBuildRet(p->builder, LLVMConstInt(lb_type(m, t_bool), 0, false));
+	} else if (type->kind == Type_Union) {
+		if (is_type_union_maybe_pointer(type)) {
+			Type *v = type->Union.variants[0];
+			Type *pv = alloc_type_pointer(v);
+
+			lbValue left = lb_emit_load(p, lb_emit_conv(p, lhs, pv));
+			lbValue right = lb_emit_load(p, lb_emit_conv(p, rhs, pv));
+
+			lbValue ok = lb_emit_comp(p, Token_CmpEq, left, right);
+			ok = lb_emit_conv(p, ok, t_bool);
+			LLVMBuildRet(p->builder, ok.value);
+		} else {
+			lbBlock *block_false = lb_create_block(p, "bfalse");
+			lbBlock *block_switch = lb_create_block(p, "bswitch");
+
+			lbValue left_tag  = lb_emit_load(p, lb_emit_union_tag_ptr(p, lhs));
+			lbValue right_tag = lb_emit_load(p, lb_emit_union_tag_ptr(p, rhs));
+
+			lbValue tag_eq = lb_emit_comp(p, Token_CmpEq, left_tag, right_tag);
+			lb_emit_if(p, tag_eq, block_switch, block_false);
+
+			lb_start_block(p, block_switch);
+			LLVMValueRef v_switch = LLVMBuildSwitch(p->builder, left_tag.value, block_false->block, cast(unsigned)type->Union.variants.count);
+
+
+			for_array(i, type->Union.variants) {
+				lbBlock *case_block = lb_create_block(p, "bcase");
+				lb_start_block(p, case_block);
+
+				Type *v = type->Union.variants[i];
+				lbValue case_tag = lb_const_union_tag(p->module, type, v);
+
+				Type *vp = alloc_type_pointer(v);
+
+				lbValue left  = lb_emit_load(p, lb_emit_conv(p, lhs, vp));
+				lbValue right = lb_emit_load(p, lb_emit_conv(p, rhs, vp));
+				lbValue ok = lb_emit_comp(p, Token_CmpEq, left, right);
+				ok = lb_emit_conv(p, ok, t_bool);
+
+				LLVMBuildRet(p->builder, ok.value);
+
+
+				LLVMAddCase(v_switch, case_tag.value, case_block->block);
+			}
+
+			lb_start_block(p, block_false);
+
+			LLVMBuildRet(p->builder, LLVMConstInt(lb_type(m, t_bool), 0, false));
+		}
+
 	} else {
 		lbValue left = lb_emit_load(p, lhs);
 		lbValue right = lb_emit_load(p, rhs);
@@ -10336,6 +10683,9 @@ lbValue lb_get_hasher_proc_for_type(lbModule *m, Type *type) {
 	lbValue data = {x, t_rawptr};
 	lbValue seed = {y, t_uintptr};
 
+	LLVMAttributeRef nonnull_attr = lb_create_enum_attribute(m->ctx, "nonnull");
+	LLVMAddAttributeAtIndex(p->value, 1+0, nonnull_attr);
+
 	if (is_type_simple_compare(type)) {
 		lbValue res = lb_simple_compare_hash(p, type, data, seed);
 		LLVMBuildRet(p->builder, res.value);
@@ -10358,6 +10708,48 @@ lbValue lb_get_hasher_proc_for_type(lbModule *m, Type *type) {
 			seed = lb_emit_call(p, field_hasher, args);
 		}
 		LLVMBuildRet(p->builder, seed.value);
+	} else if (type->kind == Type_Union)  {
+		auto args = array_make<lbValue>(permanent_allocator(), 2);
+
+		if (is_type_union_maybe_pointer(type)) {
+			Type *v = type->Union.variants[0];
+			lbValue variant_hasher = lb_get_hasher_proc_for_type(m, v);
+
+			args[0] = data;
+			args[1] = seed;
+			lbValue res = lb_emit_call(p, variant_hasher, args);
+			LLVMBuildRet(p->builder, res.value);
+		}
+
+		lbBlock *end_block = lb_create_block(p, "bend");
+		data = lb_emit_conv(p, data, pt);
+
+		lbValue tag_ptr = lb_emit_union_tag_ptr(p, data);
+		lbValue tag = lb_emit_load(p, tag_ptr);
+
+		LLVMValueRef v_switch = LLVMBuildSwitch(p->builder, tag.value, end_block->block, cast(unsigned)type->Union.variants.count);
+
+		for_array(i, type->Union.variants) {
+			lbBlock *case_block = lb_create_block(p, "bcase");
+			lb_start_block(p, case_block);
+
+			Type *v = type->Union.variants[i];
+			Type *vp = alloc_type_pointer(v);
+			lbValue case_tag = lb_const_union_tag(p->module, type, v);
+
+			lbValue variant_hasher = lb_get_hasher_proc_for_type(m, v);
+
+			args[0] = data;
+			args[1] = seed;
+			lbValue res = lb_emit_call(p, variant_hasher, args);
+			LLVMBuildRet(p->builder, res.value);
+
+			LLVMAddCase(v_switch, case_tag.value, case_block->block);
+		}
+
+		lb_start_block(p, end_block);
+		LLVMBuildRet(p->builder, seed.value);
+
 	} else if (type->kind == Type_Array) {
 		lbAddr pres = lb_add_local_generated(p, t_uintptr, false);
 		lb_addr_store(p, pres, seed);
@@ -10419,6 +10811,30 @@ lbValue lb_get_hasher_proc_for_type(lbModule *m, Type *type) {
 	return {p->value, p->type};
 }
 
+lbValue lb_compare_records(lbProcedure *p, TokenKind op_kind, lbValue left, lbValue right, Type *type) {
+	GB_ASSERT((is_type_struct(type) || is_type_union(type)) && is_type_comparable(type));
+	lbValue left_ptr  = lb_address_from_load_or_generate_local(p, left);
+	lbValue right_ptr = lb_address_from_load_or_generate_local(p, right);
+	lbValue res = {};
+	if (is_type_simple_compare(type)) {
+		// TODO(bill): Test to see if this is actually faster!!!!
+		auto args = array_make<lbValue>(permanent_allocator(), 3);
+		args[0] = lb_emit_conv(p, left_ptr, t_rawptr);
+		args[1] = lb_emit_conv(p, right_ptr, t_rawptr);
+		args[2] = lb_const_int(p->module, t_int, type_size_of(type));
+		res = lb_emit_runtime_call(p, "memory_equal", args);
+	} else {
+		lbValue value = lb_get_equal_proc_for_type(p->module, type);
+		auto args = array_make<lbValue>(permanent_allocator(), 2);
+		args[0] = lb_emit_conv(p, left_ptr, t_rawptr);
+		args[1] = lb_emit_conv(p, right_ptr, t_rawptr);
+		res = lb_emit_call(p, value, args);
+	}
+	if (op_kind == Token_NotEq) {
+		res = lb_emit_unary_arith(p, Token_Not, res, res.type);
+	}
+	return res;
+}
 
 
 lbValue lb_emit_comp(lbProcedure *p, TokenKind op_kind, lbValue left, lbValue right) {
@@ -10447,42 +10863,22 @@ lbValue lb_emit_comp(lbProcedure *p, TokenKind op_kind, lbValue left, lbValue ri
 		Type *lt = left.type;
 		Type *rt = right.type;
 
-		// if (is_type_bit_set(lt) && is_type_bit_set(rt)) {
-		// 	Type *blt = base_type(lt);
-		// 	Type *brt = base_type(rt);
-		// 	i64 bits = gb_max(blt->BitSet.bits, brt->BitSet.bits);
-		// 	i64 bytes = bits / 8;
-		// 	switch (bytes) {
-		// 	case 1:
-		// 		left = lb_emit_conv(p, left, t_u8);
-		// 		right = lb_emit_conv(p, right, t_u8);
-		// 		break;
-		// 	case 2:
-		// 		left = lb_emit_conv(p, left, t_u16);
-		// 		right = lb_emit_conv(p, right, t_u16);
-		// 		break;
-		// 	case 4:
-		// 		left = lb_emit_conv(p, left, t_u32);
-		// 		right = lb_emit_conv(p, right, t_u32);
-		// 		break;
-		// 	case 8:
-		// 		left = lb_emit_conv(p, left, t_u64);
-		// 		right = lb_emit_conv(p, right, t_u64);
-		// 		break;
-		// 	default: GB_PANIC("Unknown integer size"); break;
-		// 	}
-		// }
-
 		lt = left.type;
 		rt = right.type;
 		i64 ls = type_size_of(lt);
 		i64 rs = type_size_of(rt);
+
+		// NOTE(bill): Quick heuristic, larger types are usually the target type
 		if (ls < rs) {
 			left = lb_emit_conv(p, left, rt);
 		} else if (ls > rs) {
 			right = lb_emit_conv(p, right, lt);
 		} else {
-			right = lb_emit_conv(p, right, lt);
+			if (is_type_union(rt)) {
+				left = lb_emit_conv(p, left, rt);
+			} else {
+				right = lb_emit_conv(p, right, lt);
+			}
 		}
 	}
 
@@ -10548,28 +10944,12 @@ lbValue lb_emit_comp(lbProcedure *p, TokenKind op_kind, lbValue left, lbValue ri
 	}
 
 
-	if (is_type_struct(a) && is_type_comparable(a)) {
-		lbValue left_ptr  = lb_address_from_load_or_generate_local(p, left);
-		lbValue right_ptr = lb_address_from_load_or_generate_local(p, right);
-		lbValue res = {};
-		if (is_type_simple_compare(a)) {
-			// TODO(bill): Test to see if this is actually faster!!!!
-			auto args = array_make<lbValue>(permanent_allocator(), 3);
-			args[0] = lb_emit_conv(p, left_ptr, t_rawptr);
-			args[1] = lb_emit_conv(p, right_ptr, t_rawptr);
-			args[2] = lb_const_int(p->module, t_int, type_size_of(a));
-			res = lb_emit_runtime_call(p, "memory_equal", args);
-		} else {
-			lbValue value = lb_get_equal_proc_for_type(p->module, a);
-			auto args = array_make<lbValue>(permanent_allocator(), 2);
-			args[0] = lb_emit_conv(p, left_ptr, t_rawptr);
-			args[1] = lb_emit_conv(p, right_ptr, t_rawptr);
-			res = lb_emit_call(p, value, args);
-		}
-		if (op_kind == Token_NotEq) {
-			res = lb_emit_unary_arith(p, Token_Not, res, res.type);
-		}
-		return res;
+	if ((is_type_struct(a) || is_type_union(a)) && is_type_comparable(a)) {
+		return lb_compare_records(p, op_kind, left, right, a);
+	}
+
+	if ((is_type_struct(b) || is_type_union(b)) && is_type_comparable(b)) {
+		return lb_compare_records(p, op_kind, left, right, b);
 	}
 
 	if (is_type_string(a)) {
@@ -10783,12 +11163,9 @@ lbValue lb_emit_comp(lbProcedure *p, TokenKind op_kind, lbValue left, lbValue ri
 
 
 lbValue lb_generate_anonymous_proc_lit(lbModule *m, String const &prefix_name, Ast *expr, lbProcedure *parent) {
-	auto *found = map_get(&m->anonymous_proc_lits, hash_pointer(expr));
-	if (found != nullptr) {
-		lbValue value = {};
-		value.value = (*found)->value;
-		value.type = (*found)->type;
-		return value;
+	lbProcedure **found = map_get(&m->gen->anonymous_proc_lits, hash_pointer(expr));
+	if (found) {
+		return lb_find_procedure_value_from_entity(m, (*found)->entity);
 	}
 
 	ast_node(pl, ProcLit, expr);
@@ -10797,7 +11174,7 @@ lbValue lb_generate_anonymous_proc_lit(lbModule *m, String const &prefix_name, A
 	// parent$count
 	isize name_len = prefix_name.len + 1 + 8 + 1;
 	char *name_text = gb_alloc_array(permanent_allocator(), char, name_len);
-	i32 name_id = cast(i32)m->anonymous_proc_lits.entries.count;
+	i32 name_id = cast(i32)m->gen->anonymous_proc_lits.entries.count;
 
 	name_len = gb_snprintf(name_text, name_len, "%.*s$anon-%d", LIT(prefix_name), name_id);
 	String name = make_string((u8 *)name_text, name_len-1);
@@ -10811,6 +11188,7 @@ lbValue lb_generate_anonymous_proc_lit(lbModule *m, String const &prefix_name, A
 	Entity *e = alloc_entity_procedure(nullptr, token, type, pl->tags);
 	e->file = expr->file;
 	e->decl_info = pl->decl;
+	e->code_gen_module = m;
 	lbProcedure *p = lb_create_procedure(m, e);
 
 	lbValue value = {};
@@ -10825,11 +11203,59 @@ lbValue lb_generate_anonymous_proc_lit(lbModule *m, String const &prefix_name, A
 	}
 
 	map_set(&m->anonymous_proc_lits, hash_pointer(expr), p);
+	map_set(&m->gen->anonymous_proc_lits, hash_pointer(expr), p);
 
 	return value;
 }
 
-lbValue lb_emit_union_cast(lbProcedure *p, lbValue value, Type *type, TokenPos pos, bool do_conversion_check=true) {
+lbValue lb_emit_union_cast_only_ok_check(lbProcedure *p, lbValue value, Type *type, TokenPos pos) {
+	GB_ASSERT(is_type_tuple(type));
+	lbModule *m = p->module;
+
+	Type *src_type = value.type;
+	bool is_ptr = is_type_pointer(src_type);
+
+
+	// IMPORTANT NOTE(bill): This assumes that the value is completely ignored
+	// so when it does an assignment, it complete ignores the value.
+	// Just make it two booleans and ignore the first one
+	//
+	// _, ok := x.(T);
+	//
+	Type *ok_type = type->Tuple.variables[1]->type;
+	Type *gen_tuple_types[2] = {};
+	gen_tuple_types[0] = ok_type;
+	gen_tuple_types[1] = ok_type;
+
+	Type *gen_tuple = alloc_type_tuple_from_field_types(gen_tuple_types, gb_count_of(gen_tuple_types), false, true);
+
+	lbAddr v = lb_add_local_generated(p, gen_tuple, false);
+
+	if (is_ptr) {
+		value = lb_emit_load(p, value);
+	}
+	Type *src = base_type(type_deref(src_type));
+	GB_ASSERT_MSG(is_type_union(src), "%s", type_to_string(src_type));
+	Type *dst = type->Tuple.variables[0]->type;
+
+	lbValue cond = {};
+
+	if (is_type_union_maybe_pointer(src)) {
+		lbValue data = lb_emit_transmute(p, value, dst);
+		cond = lb_emit_comp_against_nil(p, Token_NotEq, data);
+	} else {
+		lbValue tag = lb_emit_union_tag_value(p, value);
+		lbValue dst_tag = lb_const_union_tag(m, src, dst);
+		cond = lb_emit_comp(p, Token_CmpEq, tag, dst_tag);
+	}
+
+	lbValue gep1 = lb_emit_struct_ep(p, v.addr, 1);
+	lb_emit_store(p, gep1, cond);
+
+	return lb_addr_load(p, v);
+}
+
+lbValue lb_emit_union_cast(lbProcedure *p, lbValue value, Type *type, TokenPos pos) {
 	lbModule *m = p->module;
 
 	Type *src_type = value.type;
@@ -10893,7 +11319,7 @@ lbValue lb_emit_union_cast(lbProcedure *p, lbValue value, Type *type, TokenPos p
 	lb_start_block(p, end_block);
 
 	if (!is_tuple) {
-		if (do_conversion_check) {
+		{
 			// NOTE(bill): Panic on invalid conversion
 			Type *dst_type = tuple->Tuple.variables[0]->type;
 
@@ -10981,15 +11407,66 @@ lbValue lb_emit_any_cast(lbProcedure *p, lbValue value, Type *type, TokenPos pos
 }
 
 
+lbValue lb_find_ident(lbProcedure *p, lbModule *m, Entity *e, Ast *expr) {
+	auto *found = map_get(&m->values, hash_entity(e));
+	if (found) {
+		auto v = *found;
+		// NOTE(bill): This is because pointers are already pointers in LLVM
+		if (is_type_proc(v.type)) {
+			return v;
+		}
+		return lb_emit_load(p, v);
+	} else if (e != nullptr && e->kind == Entity_Variable) {
+		return lb_addr_load(p, lb_build_addr(p, expr));
+	}
+
+	if (e->kind == Entity_Procedure) {
+		return lb_find_procedure_value_from_entity(m, e);
+	}
+	if (USE_SEPARTE_MODULES) {
+		lbModule *other_module = lb_pkg_module(m->gen, e->pkg);
+		if (other_module != m) {
+
+			String name = lb_get_entity_name(other_module, e);
+
+			lbValue g = {};
+			g.value = LLVMAddGlobal(m->mod, lb_type(m, e->type), alloc_cstring(permanent_allocator(), name));
+			g.type = alloc_type_pointer(e->type);
+			LLVMSetLinkage(g.value, LLVMExternalLinkage);
+
+			lb_add_entity(m, e, g);
+			lb_add_member(m, name, g);
+			return lb_emit_load(p, g);
+		}
+	}
+
+	String pkg = {};
+	if (e->pkg) {
+		pkg = e->pkg->name;
+	}
+	gb_printf_err("Error in: %s\n", token_pos_to_string(ast_token(expr).pos));
+	GB_PANIC("nullptr value for expression from identifier: %.*s.%.*s (%p) : %s @ %p", LIT(pkg), LIT(e->token.string), e, type_to_string(e->type), expr);
+	return {};
+}
+
+bool lb_is_expr_constant_zero(Ast *expr) {
+	GB_ASSERT(expr != nullptr);
+	auto v = exact_value_to_integer(expr->tav.value);
+	if (v.kind == ExactValue_Integer) {
+		return big_int_cmp_zero(&v.value_integer) == 0;
+	}
+	return false;
+}
+
 lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 	lbModule *m = p->module;
 
-	u64 prev_state_flags = p->module->state_flags;
-	defer (p->module->state_flags = prev_state_flags);
+	u16 prev_state_flags = p->state_flags;
+	defer (p->state_flags = prev_state_flags);
 
 	if (expr->state_flags != 0) {
-		u64 in = expr->state_flags;
-		u64 out = p->module->state_flags;
+		u16 in = expr->state_flags;
+		u16 out = p->state_flags;
 
 		if (in & StateFlag_bounds_check) {
 			out |= StateFlag_bounds_check;
@@ -10999,7 +11476,7 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 			out &= ~StateFlag_bounds_check;
 		}
 
-		p->module->state_flags = out;
+		p->state_flags = out;
 	}
 
 	expr = unparen_expr(expr);
@@ -11009,6 +11486,12 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 	GB_ASSERT_MSG(tv.mode != Addressing_Invalid, "invalid expression '%s' (tv.mode = %d, tv.type = %s) @ %s\n Current Proc: %.*s : %s", expr_to_string(expr), tv.mode, type_to_string(tv.type), token_pos_to_string(expr_pos), LIT(p->name), type_to_string(p->type));
 
 	if (tv.value.kind != ExactValue_Invalid) {
+		// NOTE(bill): The commented out code below is just for debug purposes only
+		// GB_ASSERT_MSG(!is_type_untyped(tv.type), "%s @ %s\n%s", type_to_string(tv.type), token_pos_to_string(expr_pos), expr_to_string(expr));
+		// if (is_type_untyped(tv.type)) {
+		// 	gb_printf_err("%s %s\n", token_pos_to_string(expr_pos), expr_to_string(expr));
+		// }
+
 		// NOTE(bill): Short on constant values
 		return lb_const_value(p->module, tv.type, tv.value);
 	}
@@ -11032,7 +11515,7 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 
 	case_ast_node(bd, BasicDirective, expr);
 		TokenPos pos = bd->token.pos;
-		GB_PANIC("Non-constant basic literal %s - %.*s", token_pos_to_string(pos), LIT(bd->name));
+		GB_PANIC("Non-constant basic literal %s - %.*s", token_pos_to_string(pos), LIT(bd->name.string));
 	case_end;
 
 	case_ast_node(i, Implicit, expr);
@@ -11070,24 +11553,7 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 		}
 		GB_ASSERT(e->kind != Entity_ProcGroup);
 
-		auto *found = map_get(&p->module->values, hash_entity(e));
-		if (found) {
-			auto v = *found;
-			// NOTE(bill): This is because pointers are already pointers in LLVM
-			if (is_type_proc(v.type)) {
-				return v;
-			}
-			return lb_emit_load(p, v);
-		} else if (e != nullptr && e->kind == Entity_Variable) {
-			return lb_addr_load(p, lb_build_addr(p, expr));
-		}
-		gb_printf_err("Error in: %s\n", token_pos_to_string(i->token.pos));
-		String pkg = {};
-		if (e->pkg) {
-			pkg = e->pkg->name;
-		}
-		GB_PANIC("nullptr value for expression from identifier: %.*s.%.*s (%p) : %s @ %p", LIT(pkg), LIT(e->token.string), e, type_to_string(e->type), expr);
-		return {};
+		return lb_find_ident(p, m, e, expr);
 	case_end;
 
 	case_ast_node(de, DerefExpr, expr);
@@ -11114,47 +11580,6 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 		return lb_build_expr(p, se->call);
 	case_end;
 
-	case_ast_node(te, TernaryExpr, expr);
-		LLVMValueRef incoming_values[2] = {};
-		LLVMBasicBlockRef incoming_blocks[2] = {};
-
-		GB_ASSERT(te->y != nullptr);
-		lbBlock *then  = lb_create_block(p, "if.then");
-		lbBlock *done  = lb_create_block(p, "if.done"); // NOTE(bill): Append later
-		lbBlock *else_ = lb_create_block(p, "if.else");
-
-		lbValue cond = lb_build_cond(p, te->cond, then, else_);
-		lb_start_block(p, then);
-
-		Type *type = default_type(type_of_expr(expr));
-
-		lb_open_scope(p, nullptr);
-		incoming_values[0] = lb_emit_conv(p, lb_build_expr(p, te->x), type).value;
-		lb_close_scope(p, lbDeferExit_Default, nullptr);
-
-		lb_emit_jump(p, done);
-		lb_start_block(p, else_);
-
-		lb_open_scope(p, nullptr);
-		incoming_values[1] = lb_emit_conv(p, lb_build_expr(p, te->y), type).value;
-		lb_close_scope(p, lbDeferExit_Default, nullptr);
-
-		lb_emit_jump(p, done);
-		lb_start_block(p, done);
-
-		lbValue res = {};
-		res.value = LLVMBuildPhi(p->builder, lb_type(p->module, type), "");
-		res.type = type;
-
-		GB_ASSERT(p->curr_block->preds.count >= 2);
-		incoming_blocks[0] = p->curr_block->preds[0]->block;
-		incoming_blocks[1] = p->curr_block->preds[1]->block;
-
-		LLVMAddIncoming(res.value, incoming_values, incoming_blocks, 2);
-
-		return res;
-	case_end;
-
 	case_ast_node(te, TernaryIfExpr, expr);
 		LLVMValueRef incoming_values[2] = {};
 		LLVMBasicBlockRef incoming_blocks[2] = {};
@@ -11213,6 +11638,10 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 		lbValue e = lb_build_expr(p, ta->expr);
 		Type *t = type_deref(e.type);
 		if (is_type_union(t)) {
+			if (ta->ignores[0]) {
+				// NOTE(bill): This is not needed for optimization levels other than 0
+				return lb_emit_union_cast_only_ok_check(p, e, type, pos);
+			}
 			return lb_emit_union_cast(p, e, type, pos);
 		} else if (is_type_any(t)) {
 			return lb_emit_any_cast(p, e, type, pos);
@@ -11358,6 +11787,13 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 	case_end;
 
 	case_ast_node(se, SliceExpr, expr);
+		if (is_type_slice(type_of_expr(se->expr))) {
+			// NOTE(bill): Quick optimization
+			if (se->high == nullptr &&
+			    (se->low == nullptr || lb_is_expr_constant_zero(se->low))) {
+				return lb_build_expr(p, se->expr);
+			}
+		}
 		return lb_addr_load(p, lb_build_addr(p, expr));
 	case_end;
 
@@ -11436,7 +11872,13 @@ lbValue lb_get_using_variable(lbProcedure *p, Entity *e) {
 	GB_ASSERT(v.value != nullptr);
 	GB_ASSERT_MSG(parent->type == type_deref(v.type), "%s %s", type_to_string(parent->type), type_to_string(v.type));
 	lbValue ptr = lb_emit_deep_field_gep(p, v, sel);
-	lb_add_debug_local_variable(p, ptr.value, e->type, e->token);
+	if (parent->scope) {
+		if ((parent->scope->flags & (ScopeFlag_File|ScopeFlag_Pkg)) == 0) {
+			lb_add_debug_local_variable(p, ptr.value, e->type, e->token);
+		}
+	} else {
+		lb_add_debug_local_variable(p, ptr.value, e->type, e->token);
+	}
 	return ptr;
 }
 
@@ -11462,11 +11904,14 @@ lbAddr lb_build_addr_from_entity(lbProcedure *p, Entity *e, Ast *expr) {
 		return lb_get_soa_variable_addr(p, e);
 	}
 
+
 	if (v.value == nullptr) {
-		error(expr, "%.*s Unknown value: %.*s, entity: %p %.*s",
-		      LIT(p->name),
-		      LIT(e->token.string), e, LIT(entity_strings[e->kind]));
-		GB_PANIC("Unknown value");
+		return lb_addr(lb_find_value_from_entity(p->module, e));
+
+		// error(expr, "%.*s Unknown value: %.*s, entity: %p %.*s",
+		//       LIT(p->name),
+		//       LIT(e->token.string), e, LIT(entity_strings[e->kind]));
+		// GB_PANIC("Unknown value");
 	}
 
 	return lb_addr(v);
@@ -11813,27 +12258,6 @@ lbAddr lb_build_addr(lbProcedure *p, Ast *expr) {
 			return lb_addr(val);
 		}
 
-		if (!is_type_indexable(t)) {
-			AtomOpMapEntry *found = map_get(&p->module->info->atom_op_map, hash_pointer(expr));
-			if (found != nullptr) {
-				if (found->kind == TypeAtomOp_index_get) {
-					return lb_build_addr(p, found->node);
-				} else if (found->kind == TypeAtomOp_index_get_ptr) {
-					return lb_addr(lb_build_expr(p, found->node));
-				} else if (found->kind == TypeAtomOp_index_set) {
-					lbValue ptr = lb_build_addr_ptr(p, ie->expr);
-					if (deref) {
-						ptr = lb_emit_load(p, ptr);
-					}
-
-					lbAddr addr = {lbAddr_AtomOp_index_set};
-					addr.addr = ptr;
-					addr.index_set.index = lb_build_expr(p, ie->index);
-					addr.index_set.node = found->node;
-					return addr;
-				}
-			}
-		}
 		GB_ASSERT_MSG(is_type_indexable(t), "%s %s", type_to_string(t), expr_to_string(expr));
 
 		if (is_type_map(t)) {
@@ -11969,6 +12393,7 @@ lbAddr lb_build_addr(lbProcedure *p, Ast *expr) {
 	case_end;
 
 	case_ast_node(se, SliceExpr, expr);
+
 		lbValue low  = lb_const_int(p->module, t_int, 0);
 		lbValue high = {};
 
@@ -11977,36 +12402,6 @@ lbAddr lb_build_addr(lbProcedure *p, Ast *expr) {
 
 		bool no_indices = se->low == nullptr && se->high == nullptr;
 
-		{
-			Type *type = base_type(type_of_expr(se->expr));
-			if (type->kind == Type_Struct && !is_type_soa_struct(type)) {
-				TypeAtomOpTable *atom_op_table = type->Struct.atom_op_table;
-				if (atom_op_table != nullptr && atom_op_table->op[TypeAtomOp_slice]) {
-					AtomOpMapEntry *found = map_get(&p->module->info->atom_op_map, hash_pointer(expr));
-					if (found) {
-						lbValue base = lb_build_expr(p, found->node);
-
-						Type *slice_type = base.type;
-						lbValue len = lb_slice_len(p, base);
-						if (high.value == nullptr) high = len;
-
-						if (!no_indices) {
-							lb_emit_slice_bounds_check(p, se->open, low, high, len, se->low != nullptr);
-						}
-
-
-						lbValue elem    = lb_emit_ptr_offset(p, lb_slice_elem(p, base), low);
-						lbValue new_len = lb_emit_arith(p, Token_Sub, high, low, t_int);
-
-						lbAddr slice = lb_add_local_generated(p, slice_type, false);
-						lb_fill_slice(p, slice, elem, new_len);
-						return slice;
-					}
-				}
-			}
-		}
-
-
 		lbAddr addr = lb_build_addr(p, se->expr);
 		lbValue base = lb_addr_load(p, addr);
 		Type *type = base_type(base.type);
@@ -12780,8 +13175,16 @@ lbAddr lb_build_addr(lbProcedure *p, Ast *expr) {
 void lb_init_module(lbModule *m, Checker *c) {
 	m->info = &c->info;
 
-	m->ctx = LLVMGetGlobalContext();
-	m->mod = LLVMModuleCreateWithNameInContext("odin_module", m->ctx);
+	gbString module_name = gb_string_make(heap_allocator(), "odin_package");
+	if (m->pkg) {
+		module_name = gb_string_appendc(module_name, "-");
+		module_name = gb_string_append_length(module_name, m->pkg->name.text, m->pkg->name.len);
+	} else if (USE_SEPARTE_MODULES) {
+		module_name = gb_string_appendc(module_name, "-builtin");
+	}
+
+	m->ctx = LLVMContextCreate();
+	m->mod = LLVMModuleCreateWithNameInContext(module_name ? module_name : "odin_package", m->ctx);
 	// m->debug_builder = nullptr;
 	if (build_context.ODIN_DEBUG) {
 		enum {DEBUG_METADATA_VERSION = 3};
@@ -12808,10 +13211,6 @@ void lb_init_module(lbModule *m, Checker *c) {
 		m->debug_builder = LLVMCreateDIBuilder(m->mod);
 	}
 
-	m->state_flags = 0;
-	m->state_flags |= StateFlag_bounds_check;
-
-	gb_mutex_init(&m->mutex);
 	gbAllocator a = heap_allocator();
 	map_init(&m->types, a);
 	map_init(&m->llvm_types, a);
@@ -12870,6 +13269,7 @@ bool lb_init_generator(lbGenerator *gen, Checker *c) {
 	}
 	gbAllocator ha = heap_allocator();
 	array_init(&gen->output_object_paths, ha);
+	array_init(&gen->output_temp_paths, ha);
 
 	gen->output_base = path_to_full_path(ha, gen->output_base);
 
@@ -12879,8 +13279,34 @@ bool lb_init_generator(lbGenerator *gen, Checker *c) {
 
 	gen->info = &c->info;
 
-	lb_init_module(&gen->module, c);
+	map_init(&gen->modules, permanent_allocator(), gen->info->packages.entries.count*2);
+	map_init(&gen->modules_through_ctx, permanent_allocator(), gen->info->packages.entries.count*2);
+	map_init(&gen->anonymous_proc_lits, heap_allocator(), 1024);
+
+	gb_mutex_init(&gen->mutex);
 
+	if (USE_SEPARTE_MODULES) {
+		for_array(i, gen->info->packages.entries) {
+			AstPackage *pkg = gen->info->packages.entries[i].value;
+
+			auto m = gb_alloc_item(permanent_allocator(), lbModule);
+			m->pkg = pkg;
+			m->gen = gen;
+			map_set(&gen->modules, hash_pointer(pkg), m);
+			lb_init_module(m, c);
+		}
+	}
+
+	gen->default_module.gen = gen;
+	map_set(&gen->modules, hash_pointer(nullptr), &gen->default_module);
+	lb_init_module(&gen->default_module, c);
+
+
+	for_array(i, gen->modules.entries) {
+		lbModule *m = gen->modules.entries[i].value;
+		LLVMContextRef ctx = LLVMGetModuleContext(m->mod);
+		map_set(&gen->modules_through_ctx, hash_pointer(ctx), m);
+	}
 
 	return true;
 }
@@ -12891,8 +13317,10 @@ lbAddr lb_add_global_generated(lbModule *m, Type *type, lbValue value) {
 
 	isize max_len = 7+8+1;
 	u8 *str = cast(u8 *)gb_alloc_array(permanent_allocator(), u8, max_len);
-	isize len = gb_snprintf(cast(char *)str, max_len, "ggv$%x", m->global_generated_index);
-	m->global_generated_index++;
+
+	u32 id = cast(u32)gb_atomic32_fetch_add(&m->gen->global_generated_index, 1);
+
+	isize len = gb_snprintf(cast(char *)str, max_len, "ggv$%x", id);
 	String name = make_string(str, len-1);
 
 	Scope *scope = nullptr;
@@ -12901,7 +13329,7 @@ lbAddr lb_add_global_generated(lbModule *m, Type *type, lbValue value) {
 	g.type = alloc_type_pointer(type);
 	g.value = LLVMAddGlobal(m->mod, lb_type(m, type), cast(char const *)str);
 	if (value.value != nullptr) {
-		GB_ASSERT(LLVMIsConstant(value.value));
+		GB_ASSERT_MSG(LLVMIsConstant(value.value), LLVMPrintValueToString(value.value));
 		LLVMSetInitializer(g.value, value.value);
 	} else {
 		LLVMSetInitializer(g.value, LLVMConstNull(lb_type(m, type)));
@@ -12915,17 +13343,12 @@ lbAddr lb_add_global_generated(lbModule *m, Type *type, lbValue value) {
 lbValue lb_find_runtime_value(lbModule *m, String const &name) {
 	AstPackage *p = m->info->runtime_package;
 	Entity *e = scope_lookup_current(p->scope, name);
-	lbValue *found = map_get(&m->values, hash_entity(e));
-	GB_ASSERT_MSG(found != nullptr, "Unable to find runtime value '%.*s'", LIT(name));
-	lbValue value = *found;
-	return value;
+	return lb_find_value_from_entity(m, e);
 }
 lbValue lb_find_package_value(lbModule *m, String const &pkg, String const &name) {
 	Entity *e = find_entity_in_pkg(m->info, pkg, name);
 	lbValue *found = map_get(&m->values, hash_entity(e));
-	GB_ASSERT_MSG(found != nullptr, "Unable to find value '%.*s.%.*s'", LIT(pkg), LIT(name));
-	lbValue value = *found;
-	return value;
+	return lb_find_value_from_entity(m, e);
 }
 
 lbValue lb_get_type_info_ptr(lbModule *m, Type *type) {
@@ -12940,32 +13363,37 @@ lbValue lb_get_type_info_ptr(lbModule *m, Type *type) {
 
 	lbValue res = {};
 	res.type = t_type_info_ptr;
-	res.value = LLVMConstGEP(lb_global_type_info_data.addr.value, indices, cast(unsigned)gb_count_of(indices));
+	res.value = LLVMConstGEP(lb_global_type_info_data_ptr(m).value, indices, cast(unsigned)gb_count_of(indices));
 	return res;
 }
 
 
 lbValue lb_type_info_member_types_offset(lbProcedure *p, isize count) {
+	GB_ASSERT(p->module == &p->module->gen->default_module);
 	lbValue offset = lb_emit_array_epi(p, lb_global_type_info_member_types.addr, lb_global_type_info_member_types_index);
 	lb_global_type_info_member_types_index += cast(i32)count;
 	return offset;
 }
 lbValue lb_type_info_member_names_offset(lbProcedure *p, isize count) {
+	GB_ASSERT(p->module == &p->module->gen->default_module);
 	lbValue offset = lb_emit_array_epi(p, lb_global_type_info_member_names.addr, lb_global_type_info_member_names_index);
 	lb_global_type_info_member_names_index += cast(i32)count;
 	return offset;
 }
 lbValue lb_type_info_member_offsets_offset(lbProcedure *p, isize count) {
+	GB_ASSERT(p->module == &p->module->gen->default_module);
 	lbValue offset = lb_emit_array_epi(p, lb_global_type_info_member_offsets.addr, lb_global_type_info_member_offsets_index);
 	lb_global_type_info_member_offsets_index += cast(i32)count;
 	return offset;
 }
 lbValue lb_type_info_member_usings_offset(lbProcedure *p, isize count) {
+	GB_ASSERT(p->module == &p->module->gen->default_module);
 	lbValue offset = lb_emit_array_epi(p, lb_global_type_info_member_usings.addr, lb_global_type_info_member_usings_index);
 	lb_global_type_info_member_usings_index += cast(i32)count;
 	return offset;
 }
 lbValue lb_type_info_member_tags_offset(lbProcedure *p, isize count) {
+	GB_ASSERT(p->module == &p->module->gen->default_module);
 	lbValue offset = lb_emit_array_epi(p, lb_global_type_info_member_tags.addr, lb_global_type_info_member_tags_index);
 	lb_global_type_info_member_tags_index += cast(i32)count;
 	return offset;
@@ -13007,12 +13435,12 @@ void lb_setup_type_info_data(lbProcedure *p) { // NOTE(bill): Setup type_info da
 	{
 		// NOTE(bill): Set the type_table slice with the global backing array
 		lbValue global_type_table = lb_find_runtime_value(m, str_lit("type_table"));
-		Type *type = base_type(lb_addr_type(lb_global_type_info_data));
+		Type *type = base_type(lb_global_type_info_data_entity->type);
 		GB_ASSERT(is_type_array(type));
 
 		LLVMValueRef indices[2] = {llvm_zero(m), llvm_zero(m)};
 		LLVMValueRef values[2] = {
-			LLVMConstInBoundsGEP(lb_global_type_info_data.addr.value, indices, gb_count_of(indices)),
+			LLVMConstInBoundsGEP(lb_global_type_info_data_ptr(m).value, indices, gb_count_of(indices)),
 			LLVMConstInt(lb_type(m, t_int), type->Array.count, true),
 		};
 		LLVMValueRef slice = llvm_const_named_struct(llvm_addr_type(global_type_table), values, gb_count_of(values));
@@ -13044,7 +13472,7 @@ void lb_setup_type_info_data(lbProcedure *p) { // NOTE(bill): Setup type_info da
 		}
 
 		lbValue tag = {};
-		lbValue ti_ptr = lb_emit_array_epi(p, lb_global_type_info_data.addr, cast(i32)entry_index);
+		lbValue ti_ptr = lb_emit_array_epi(p, lb_global_type_info_data_ptr(m), cast(i32)entry_index);
 		lbValue variant_ptr = lb_emit_struct_ep(p, ti_ptr, 4);
 
 		lbValue type_info_flags = lb_const_int(p->module, t_type_info_flags, type_info_flags_of_type(t));
@@ -13447,7 +13875,7 @@ void lb_setup_type_info_data(lbProcedure *p) { // NOTE(bill): Setup type_info da
 			tag = lb_const_ptr_cast(m, variant_ptr, t_type_info_union_ptr);
 
 			{
-				LLVMValueRef vals[6] = {};
+				LLVMValueRef vals[7] = {};
 
 				isize variant_count = gb_max(0, t->Union.variants.count);
 				lbValue memory_types = lb_type_info_member_types_offset(p, variant_count);
@@ -13476,10 +13904,19 @@ void lb_setup_type_info_data(lbProcedure *p) { // NOTE(bill): Setup type_info da
 					vals[2] = LLVMConstNull(lb_type(m, t_type_info_ptr));
 				}
 
-				vals[3] = lb_const_bool(m, t_bool, t->Union.custom_align != 0).value;
-				vals[4] = lb_const_bool(m, t_bool, t->Union.no_nil).value;
-				vals[5] = lb_const_bool(m, t_bool, t->Union.maybe).value;
+				if (is_type_comparable(t) && !is_type_simple_compare(t)) {
+					vals[3] = lb_get_equal_proc_for_type(m, t).value;
+				}
+
+				vals[4] = lb_const_bool(m, t_bool, t->Union.custom_align != 0).value;
+				vals[5] = lb_const_bool(m, t_bool, t->Union.no_nil).value;
+				vals[6] = lb_const_bool(m, t_bool, t->Union.maybe).value;
 
+				for (isize i = 0; i < gb_count_of(vals); i++) {
+					if (vals[i] == nullptr) {
+						vals[i]  = LLVMConstNull(lb_type(m, get_struct_field_type(tag.type, i)));
+					}
+				}
 
 				lbValue res = {};
 				res.type = type_deref(tag.type);
@@ -13691,18 +14128,445 @@ void lb_setup_type_info_data(lbProcedure *p) { // NOTE(bill): Setup type_info da
 	}
 }
 
+struct lbGlobalVariable {
+	lbValue var;
+	lbValue init;
+	DeclInfo *decl;
+	bool is_initialized;
+};
+
+lbProcedure *lb_create_startup_type_info(lbModule *m) {
+	LLVMPassManagerRef default_function_pass_manager = LLVMCreateFunctionPassManagerForModule(m->mod);
+	lb_populate_function_pass_manager(m, default_function_pass_manager, false, build_context.optimization_level);
+	LLVMFinalizeFunctionPassManager(default_function_pass_manager);
+
+	Type *params  = alloc_type_tuple();
+	Type *results = alloc_type_tuple();
+
+	Type *proc_type = alloc_type_proc(nullptr, nullptr, 0, nullptr, 0, false, ProcCC_CDecl);
+
+	lbProcedure *p = lb_create_dummy_procedure(m, str_lit(LB_STARTUP_TYPE_INFO_PROC_NAME), proc_type);
+	p->is_startup = true;
+
+	lb_begin_procedure_body(p);
+
+	lb_setup_type_info_data(p);
+
+	lb_end_procedure_body(p);
+
+	if (!m->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
+		gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %s\n", "main");
+		LLVMDumpValue(p->value);
+		gb_printf_err("\n\n\n\n");
+		LLVMVerifyFunction(p->value, LLVMAbortProcessAction);
+	}
+
+	lb_run_function_pass_manager(default_function_pass_manager, p);
+
+	return p;
+}
+
+lbProcedure *lb_create_startup_runtime(lbModule *main_module, lbProcedure *startup_type_info, Array<lbGlobalVariable> &global_variables) { // Startup Runtime
+	LLVMPassManagerRef default_function_pass_manager = LLVMCreateFunctionPassManagerForModule(main_module->mod);
+	lb_populate_function_pass_manager(main_module, default_function_pass_manager, false, build_context.optimization_level);
+	LLVMFinalizeFunctionPassManager(default_function_pass_manager);
+
+	Type *params  = alloc_type_tuple();
+	Type *results = alloc_type_tuple();
+
+	Type *proc_type = alloc_type_proc(nullptr, nullptr, 0, nullptr, 0, false, ProcCC_CDecl);
+
+	lbProcedure *p = lb_create_dummy_procedure(main_module, str_lit(LB_STARTUP_RUNTIME_PROC_NAME), proc_type);
+	p->is_startup = true;
+
+	lb_begin_procedure_body(p);
+
+	LLVMBuildCall2(p->builder, LLVMGetElementType(lb_type(main_module, startup_type_info->type)), startup_type_info->value, nullptr, 0, "");
+
+	for_array(i, global_variables) {
+		auto *var = &global_variables[i];
+		if (var->is_initialized) {
+			continue;
+		}
+
+		lbModule *entity_module = main_module;
+
+		Entity *e = var->decl->entity;
+		GB_ASSERT(e->kind == Entity_Variable);
+		e->code_gen_module = entity_module;
+
+		if (var->decl->init_expr != nullptr)  {
+			// gb_printf_err("%s\n", expr_to_string(var->decl->init_expr));
+			lbValue init = lb_build_expr(p, var->decl->init_expr);
+			LLVMValueKind value_kind = LLVMGetValueKind(init.value);
+			// gb_printf_err("%s %d\n", LLVMPrintValueToString(init.value));
+
+			if (lb_is_const_or_global(init)) {
+				if (!var->is_initialized) {
+					LLVMSetInitializer(var->var.value, init.value);
+					var->is_initialized = true;
+					continue;
+				}
+			} else {
+				var->init = init;
+			}
+		}
+
+		if (var->init.value != nullptr) {
+			GB_ASSERT(!var->is_initialized);
+			Type *t = type_deref(var->var.type);
+
+			if (is_type_any(t)) {
+				// NOTE(bill): Edge case for 'any' type
+				Type *var_type = default_type(var->init.type);
+				lbAddr g = lb_add_global_generated(main_module, var_type, var->init);
+				lb_addr_store(p, g, var->init);
+				lbValue gp = lb_addr_get_ptr(p, g);
+
+				lbValue data = lb_emit_struct_ep(p, var->var, 0);
+				lbValue ti   = lb_emit_struct_ep(p, var->var, 1);
+				lb_emit_store(p, data, lb_emit_conv(p, gp, t_rawptr));
+				lb_emit_store(p, ti,   lb_type_info(main_module, var_type));
+			} else {
+				LLVMTypeRef pvt = LLVMTypeOf(var->var.value);
+				LLVMTypeRef vt = LLVMGetElementType(pvt);
+				lbValue src0 = lb_emit_conv(p, var->init, t);
+				LLVMValueRef src = OdinLLVMBuildTransmute(p, src0.value, vt);
+				LLVMValueRef dst = var->var.value;
+				LLVMBuildStore(p->builder, src, dst);
+			}
+
+			var->is_initialized = true;
+		}
+	}
+
+
+	lb_end_procedure_body(p);
+
+	if (!main_module->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
+		gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %s\n", "main");
+		LLVMDumpValue(p->value);
+		gb_printf_err("\n\n\n\n");
+		LLVMVerifyFunction(p->value, LLVMAbortProcessAction);
+	}
+
+	lb_run_function_pass_manager(default_function_pass_manager, p);
+
+	return p;
+}
+
+
+lbProcedure *lb_create_main_procedure(lbModule *m, lbProcedure *startup_runtime) {
+	LLVMPassManagerRef default_function_pass_manager = LLVMCreateFunctionPassManagerForModule(m->mod);
+	lb_populate_function_pass_manager(m, default_function_pass_manager, false, build_context.optimization_level);
+	LLVMFinalizeFunctionPassManager(default_function_pass_manager);
+
+	Type *params  = alloc_type_tuple();
+	Type *results = alloc_type_tuple();
+
+	Type *t_ptr_cstring = alloc_type_pointer(t_cstring);
+
+	String name = str_lit("main");
+	if (build_context.metrics.os == TargetOs_windows && build_context.metrics.arch == TargetArch_386) {
+		name = str_lit("mainCRTStartup");
+	} else {
+		array_init(&params->Tuple.variables, permanent_allocator(), 2);
+		params->Tuple.variables[0] = alloc_entity_param(nullptr, make_token_ident("argc"), t_i32, false, true);
+		params->Tuple.variables[1] = alloc_entity_param(nullptr, make_token_ident("argv"), t_ptr_cstring, false, true);
+	}
+
+	array_init(&results->Tuple.variables, permanent_allocator(), 1);
+	results->Tuple.variables[0] = alloc_entity_param(nullptr, blank_token, t_i32, false, true);
+
+	Type *proc_type = alloc_type_proc(nullptr,
+		params, params->Tuple.variables.count,
+		results, results->Tuple.variables.count, false, ProcCC_CDecl);
+
+
+	lbProcedure *p = lb_create_dummy_procedure(m, name, proc_type);
+	p->is_startup = true;
+
+	lb_begin_procedure_body(p);
+
+	{ // initialize `runtime.args__`
+		lbValue argc = {LLVMGetParam(p->value, 0), t_i32};
+		lbValue argv = {LLVMGetParam(p->value, 1), t_ptr_cstring};
+		LLVMSetValueName2(argc.value, "argc", 4);
+		LLVMSetValueName2(argv.value, "argv", 4);
+		argc = lb_emit_conv(p, argc, t_int);
+		lbAddr args = lb_addr(lb_find_runtime_value(p->module, str_lit("args__")));
+		lb_fill_slice(p, args, argv, argc);
+	}
+
+	LLVMBuildCall2(p->builder, LLVMGetElementType(lb_type(m, startup_runtime->type)), startup_runtime->value, nullptr, 0, "");
+
+	if (build_context.command_kind == Command_test) {
+		Type *t_Internal_Test = find_type_in_pkg(m->info, str_lit("testing"), str_lit("Internal_Test"));
+		Type *array_type = alloc_type_array(t_Internal_Test, m->info->testing_procedures.count);
+		Type *slice_type = alloc_type_slice(t_Internal_Test);
+		lbAddr all_tests_array_addr = lb_add_global_generated(p->module, array_type, {});
+		lbValue all_tests_array = lb_addr_get_ptr(p, all_tests_array_addr);
+
+		LLVMTypeRef lbt_Internal_Test = lb_type(m, t_Internal_Test);
+
+		LLVMValueRef indices[2] = {};
+		indices[0] = LLVMConstInt(lb_type(m, t_i32), 0, false);
+
+		for_array(i, m->info->testing_procedures) {
+			Entity *testing_proc = m->info->testing_procedures[i];
+			String name = testing_proc->token.string;
+
+			String pkg_name = {};
+			if (testing_proc->pkg != nullptr) {
+				pkg_name = testing_proc->pkg->name;
+			}
+			lbValue v_pkg  = lb_find_or_add_entity_string(m, pkg_name);
+			lbValue v_name = lb_find_or_add_entity_string(m, name);
+			lbValue v_proc = lb_find_procedure_value_from_entity(m, testing_proc);
+
+			indices[1] = LLVMConstInt(lb_type(m, t_int), i, false);
+
+			LLVMValueRef vals[3] = {};
+			vals[0] = v_pkg.value;
+			vals[1] = v_name.value;
+			vals[2] = v_proc.value;
+			GB_ASSERT(LLVMIsConstant(vals[0]));
+			GB_ASSERT(LLVMIsConstant(vals[1]));
+			GB_ASSERT(LLVMIsConstant(vals[2]));
+
+			LLVMValueRef dst = LLVMConstInBoundsGEP(all_tests_array.value, indices, gb_count_of(indices));
+			LLVMValueRef src = llvm_const_named_struct(lbt_Internal_Test, vals, gb_count_of(vals));
+
+			LLVMBuildStore(p->builder, src, dst);
+		}
+
+		lbAddr all_tests_slice = lb_add_local_generated(p, slice_type, true);
+		lb_fill_slice(p, all_tests_slice,
+		              lb_array_elem(p, all_tests_array),
+		              lb_const_int(m, t_int, m->info->testing_procedures.count));
+
+
+		lbValue runner = lb_find_package_value(m, str_lit("testing"), str_lit("runner"));
+
+		auto args = array_make<lbValue>(heap_allocator(), 1);
+		args[0] = lb_addr_load(p, all_tests_slice);
+		lb_emit_call(p, runner, args);
+	} else {
+		lbValue entry_point = lb_find_procedure_value_from_entity(m, m->info->entry_point);
+		lb_emit_call(p, entry_point, {});
+	}
+
+	LLVMBuildRet(p->builder, LLVMConstInt(lb_type(m, t_i32), 0, false));
+
+	lb_end_procedure_body(p);
+
+	if (!m->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
+		gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %s\n", "main");
+		LLVMDumpValue(p->value);
+		gb_printf_err("\n\n\n\n");
+		LLVMVerifyFunction(p->value, LLVMAbortProcessAction);
+	}
+
+	lb_run_function_pass_manager(default_function_pass_manager, p);
+	return p;
+}
+
+String lb_filepath_ll_for_module(lbModule *m) {
+	String path = m->gen->output_base;
+	if (m->pkg) {
+		path = concatenate3_strings(permanent_allocator(), path, STR_LIT("-"), m->pkg->name);
+	} else if (USE_SEPARTE_MODULES) {
+		path = concatenate_strings(permanent_allocator(), path, STR_LIT("-builtin"));
+	}
+	path = concatenate_strings(permanent_allocator(), path, STR_LIT(".ll"));
+
+	return path;
+}
+String lb_filepath_obj_for_module(lbModule *m) {
+	String path = m->gen->output_base;
+	if (m->pkg) {
+		path = concatenate3_strings(permanent_allocator(), path, STR_LIT("-"), m->pkg->name);
+	}
+
+	String ext = {};
+
+	if (build_context.build_mode == BuildMode_Assembly) {
+		ext = STR_LIT(".S");
+	} else {
+		switch (build_context.metrics.os) {
+		case TargetOs_windows:
+			ext = STR_LIT(".obj");
+			break;
+		case TargetOs_darwin:
+		case TargetOs_linux:
+		case TargetOs_essence:
+			ext = STR_LIT(".o");
+			break;
+		case TargetOs_js:
+			ext = STR_LIT(".wasm-obj");
+			break;
+		}
+	}
+
+	return concatenate_strings(permanent_allocator(), path, ext);
+}
+
+
+bool lb_is_module_empty(lbModule *m) {
+	if (LLVMGetFirstFunction(m->mod) == nullptr &&
+	    LLVMGetFirstGlobal(m->mod) == nullptr) {
+		return true;
+	}
+	for (auto fn = LLVMGetFirstFunction(m->mod); fn != nullptr; fn = LLVMGetNextFunction(fn)) {
+		if (LLVMGetFirstBasicBlock(fn) != nullptr) {
+			return false;
+		}
+	}
+
+	for (auto g = LLVMGetFirstGlobal(m->mod); g != nullptr; g = LLVMGetNextGlobal(g)) {
+		if (LLVMGetLinkage(g) == LLVMExternalLinkage) {
+			continue;
+		}
+		if (!LLVMIsExternallyInitialized(g)) {
+			return false;
+		}
+	}
+	return true;
+}
+
+struct lbLLVMEmitWorker {
+	LLVMTargetMachineRef target_machine;
+	LLVMCodeGenFileType code_gen_file_type;
+	String filepath_obj;
+	lbModule *m;
+};
+
+WORKER_TASK_PROC(lb_llvm_emit_worker_proc) {
+	GB_ASSERT(MULTITHREAD_OBJECT_GENERATION);
+
+	char *llvm_error = nullptr;
+
+	auto wd = cast(lbLLVMEmitWorker *)data;
+
+	if (LLVMTargetMachineEmitToFile(wd->target_machine, wd->m->mod, cast(char *)wd->filepath_obj.text, wd->code_gen_file_type, &llvm_error)) {
+		gb_printf_err("LLVM Error: %s\n", llvm_error);
+		gb_exit(1);
+	}
+
+	return 0;
+}
+
+WORKER_TASK_PROC(lb_llvm_function_pass_worker_proc) {
+	GB_ASSERT(MULTITHREAD_OBJECT_GENERATION);
+
+	auto m = cast(lbModule *)data;
+
+	LLVMPassManagerRef default_function_pass_manager = LLVMCreateFunctionPassManagerForModule(m->mod);
+	LLVMPassManagerRef function_pass_manager_minimal = LLVMCreateFunctionPassManagerForModule(m->mod);
+	LLVMPassManagerRef function_pass_manager_size = LLVMCreateFunctionPassManagerForModule(m->mod);
+	LLVMPassManagerRef function_pass_manager_speed = LLVMCreateFunctionPassManagerForModule(m->mod);
+
+	LLVMInitializeFunctionPassManager(default_function_pass_manager);
+	LLVMInitializeFunctionPassManager(function_pass_manager_minimal);
+	LLVMInitializeFunctionPassManager(function_pass_manager_size);
+	LLVMInitializeFunctionPassManager(function_pass_manager_speed);
+
+	lb_populate_function_pass_manager(m, default_function_pass_manager, false, build_context.optimization_level);
+	lb_populate_function_pass_manager_specific(m, function_pass_manager_minimal, 0);
+	lb_populate_function_pass_manager_specific(m, function_pass_manager_size,    1);
+	lb_populate_function_pass_manager_specific(m, function_pass_manager_speed,   2);
+
+	LLVMFinalizeFunctionPassManager(default_function_pass_manager);
+	LLVMFinalizeFunctionPassManager(function_pass_manager_minimal);
+	LLVMFinalizeFunctionPassManager(function_pass_manager_size);
+	LLVMFinalizeFunctionPassManager(function_pass_manager_speed);
+
+
+	LLVMPassManagerRef default_function_pass_manager_without_memcpy = LLVMCreateFunctionPassManagerForModule(m->mod);
+	LLVMInitializeFunctionPassManager(default_function_pass_manager_without_memcpy);
+	lb_populate_function_pass_manager(m, default_function_pass_manager_without_memcpy, true, build_context.optimization_level);
+	LLVMFinalizeFunctionPassManager(default_function_pass_manager_without_memcpy);
+
+
+	for_array(i, m->procedures_to_generate) {
+		lbProcedure *p = m->procedures_to_generate[i];
+		if (p->body != nullptr) { // Build Procedure
+			if (p->flags & lbProcedureFlag_WithoutMemcpyPass) {
+				lb_run_function_pass_manager(default_function_pass_manager_without_memcpy, p);
+			} else {
+				if (p->entity && p->entity->kind == Entity_Procedure) {
+					switch (p->entity->Procedure.optimization_mode) {
+					case ProcedureOptimizationMode_None:
+					case ProcedureOptimizationMode_Minimal:
+						lb_run_function_pass_manager(function_pass_manager_minimal, p);
+						break;
+					case ProcedureOptimizationMode_Size:
+						lb_run_function_pass_manager(function_pass_manager_size, p);
+						break;
+					case ProcedureOptimizationMode_Speed:
+						lb_run_function_pass_manager(function_pass_manager_speed, p);
+						break;
+					default:
+						lb_run_function_pass_manager(default_function_pass_manager, p);
+						break;
+					}
+				} else {
+					lb_run_function_pass_manager(default_function_pass_manager, p);
+				}
+			}
+		}
+	}
+
+	for_array(i, m->equal_procs.entries) {
+		lbProcedure *p = m->equal_procs.entries[i].value;
+		lb_run_function_pass_manager(default_function_pass_manager, p);
+	}
+	for_array(i, m->hasher_procs.entries) {
+		lbProcedure *p = m->hasher_procs.entries[i].value;
+		lb_run_function_pass_manager(default_function_pass_manager, p);
+	}
+
+	return 0;
+}
+
+
+struct lbLLVMModulePassWorkerData {
+	lbModule *m;
+	LLVMTargetMachineRef target_machine;
+};
+
+WORKER_TASK_PROC(lb_llvm_module_pass_worker_proc) {
+	GB_ASSERT(MULTITHREAD_OBJECT_GENERATION);
+
+	auto wd = cast(lbLLVMModulePassWorkerData *)data;
+
+	LLVMPassManagerRef module_pass_manager = LLVMCreatePassManager();
+	lb_populate_module_pass_manager(wd->target_machine, module_pass_manager, build_context.optimization_level);
+	LLVMRunPassManager(module_pass_manager, wd->m->mod);
+
+	return 0;
+}
+
+
 void lb_generate_code(lbGenerator *gen) {
 	#define TIME_SECTION(str) do { if (build_context.show_more_timings) timings_start_section(&global_timings, str_lit(str)); } while (0)
+	#define TIME_SECTION_WITH_LEN(str, len) do { if (build_context.show_more_timings) timings_start_section(&global_timings, make_string((u8 *)str, len)); } while (0)
 
 	TIME_SECTION("LLVM Initializtion");
 
-	lbModule *m = &gen->module;
-	LLVMModuleRef mod = gen->module.mod;
+	isize thread_count = gb_max(build_context.thread_count, 1);
+	isize worker_count = thread_count-1;
+
+	LLVMBool do_threading = (LLVMIsMultithreaded() && USE_SEPARTE_MODULES && MULTITHREAD_OBJECT_GENERATION && worker_count > 0);
+
+	thread_pool_init(&lb_thread_pool, heap_allocator(), worker_count, "LLVMBackend");
+	defer (thread_pool_destroy(&lb_thread_pool));
+
+	lbModule *default_module = &gen->default_module;
 	CheckerInfo *info = gen->info;
 
 	auto *min_dep_set = &info->minimum_dependency_set;
 
-
 	LLVMInitializeAllTargetInfos();
 	LLVMInitializeAllTargets();
 	LLVMInitializeAllTargetMCs();
@@ -13711,16 +14575,19 @@ void lb_generate_code(lbGenerator *gen) {
 	LLVMInitializeAllDisassemblers();
 	LLVMInitializeNativeTarget();
 
-
 	char const *target_triple = alloc_cstring(permanent_allocator(), build_context.metrics.target_triplet);
 	char const *target_data_layout = alloc_cstring(permanent_allocator(), build_context.metrics.target_data_layout);
-	LLVMSetTarget(mod, target_triple);
+	for_array(i, gen->modules.entries) {
+		LLVMSetTarget(gen->modules.entries[i].value->mod, target_triple);
+	}
 
 	LLVMTargetRef target = {};
 	char *llvm_error = nullptr;
 	LLVMGetTargetFromTriple(target_triple, &target, &llvm_error);
 	GB_ASSERT(target != nullptr);
 
+
+
 	TIME_SECTION("LLVM Create Target Machine");
 
 	LLVMCodeModel code_mode = LLVMCodeModelDefault;
@@ -13754,78 +14621,89 @@ void lb_generate_code(lbGenerator *gen) {
 	}
 
 	// NOTE(bill): Target Machine Creation
-	LLVMTargetMachineRef target_machine = LLVMCreateTargetMachine(
-		target, target_triple, llvm_cpu,
-		llvm_features,
-		code_gen_level,
-		LLVMRelocDefault,
-		code_mode);
-	defer (LLVMDisposeTargetMachine(target_machine));
-
-
-	LLVMSetModuleDataLayout(mod, LLVMCreateTargetDataLayout(target_machine));
-
-	if (m->debug_builder) { // Debug Info
-		for_array(i, info->files.entries) {
-			AstFile *f = info->files.entries[i].value;
-			String fullpath = f->fullpath;
-			String filename = remove_directory_from_path(fullpath);
-			String directory = directory_from_path(fullpath);
-			LLVMMetadataRef res = LLVMDIBuilderCreateFile(m->debug_builder,
-				cast(char const *)filename.text, filename.len,
-				cast(char const *)directory.text, directory.len);
-			lb_set_llvm_metadata(m, f, res);
-		}
-
-		gbString producer = gb_string_make(heap_allocator(), "odin");
-		producer = gb_string_append_fmt(producer, " version %.*s", LIT(ODIN_VERSION));
-		#ifdef NIGHTLY
-		producer = gb_string_appendc(producer, "-nightly");
-		#endif
-		#ifdef GIT_SHA
-		producer = gb_string_append_fmt(producer, "-%s", GIT_SHA);
-		#endif
-
-		gbString split_name = gb_string_make(heap_allocator(), "");
-
-		LLVMBool is_optimized = build_context.optimization_level > 0;
-		AstFile *init_file = m->info->init_package->files[0];
-		if (m->info->entry_point && m->info->entry_point->identifier && m->info->entry_point->identifier->file) {
-			init_file = m->info->entry_point->identifier->file;
+	// NOTE(bill, 2021-05-04): Target machines must be unique to each module because they are not thread safe
+	auto target_machines = array_make<LLVMTargetMachineRef>(permanent_allocator(), gen->modules.entries.count);
+
+	for_array(i, gen->modules.entries) {
+		target_machines[i] = LLVMCreateTargetMachine(
+			target, target_triple, llvm_cpu,
+			llvm_features,
+			code_gen_level,
+			LLVMRelocDefault,
+			code_mode);
+		LLVMSetModuleDataLayout(gen->modules.entries[i].value->mod, LLVMCreateTargetDataLayout(target_machines[i]));
+	}
+
+	for_array(i, gen->modules.entries) {
+		lbModule *m = gen->modules.entries[i].value;
+		if (m->debug_builder) { // Debug Info
+			for_array(i, info->files.entries) {
+				AstFile *f = info->files.entries[i].value;
+				String fullpath = f->fullpath;
+				String filename = remove_directory_from_path(fullpath);
+				String directory = directory_from_path(fullpath);
+				LLVMMetadataRef res = LLVMDIBuilderCreateFile(m->debug_builder,
+					cast(char const *)filename.text, filename.len,
+					cast(char const *)directory.text, directory.len);
+				lb_set_llvm_metadata(m, f, res);
+			}
+
+			gbString producer = gb_string_make(heap_allocator(), "odin");
+			// producer = gb_string_append_fmt(producer, " version %.*s", LIT(ODIN_VERSION));
+			// #ifdef NIGHTLY
+			// producer = gb_string_appendc(producer, "-nightly");
+			// #endif
+			// #ifdef GIT_SHA
+			// producer = gb_string_append_fmt(producer, "-%s", GIT_SHA);
+			// #endif
+
+			gbString split_name = gb_string_make(heap_allocator(), "");
+
+			LLVMBool is_optimized = build_context.optimization_level > 0;
+			AstFile *init_file = m->info->init_package->files[0];
+			if (m->info->entry_point && m->info->entry_point->identifier && m->info->entry_point->identifier->file) {
+				init_file = m->info->entry_point->identifier->file;
+			}
+
+			LLVMBool split_debug_inlining = false;
+			LLVMBool debug_info_for_profiling = false;
+
+			m->debug_compile_unit = LLVMDIBuilderCreateCompileUnit(m->debug_builder, LLVMDWARFSourceLanguageC99,
+				lb_get_llvm_metadata(m, init_file),
+				producer, gb_string_length(producer),
+				is_optimized, "", 0,
+				1, split_name, gb_string_length(split_name),
+				LLVMDWARFEmissionFull,
+				0, split_debug_inlining,
+				debug_info_for_profiling,
+				"", 0, // sys_root
+				"", 0  // SDK
+			);
+			GB_ASSERT(m->debug_compile_unit != nullptr);
 		}
-
-		LLVMBool split_debug_inlining = false;
-		LLVMBool debug_info_for_profiling = false;
-
-		m->debug_compile_unit = LLVMDIBuilderCreateCompileUnit(m->debug_builder, LLVMDWARFSourceLanguageC99,
-			lb_get_llvm_metadata(m, init_file),
-			producer, gb_string_length(producer),
-			is_optimized, "", 0,
-			1, split_name, gb_string_length(split_name),
-			LLVMDWARFEmissionFull,
-			0, split_debug_inlining,
-			debug_info_for_profiling,
-			"", 0, // sys_root
-			"", 0  // SDK
-		);
-		GB_ASSERT(m->debug_compile_unit != nullptr);
 	}
 
 	TIME_SECTION("LLVM Global Variables");
 
 	{
+		lbModule *m = default_module;
+
 		{ // Add type info data
 			isize max_type_info_count = info->minimum_dependency_type_info_set.entries.count+1;
 			// gb_printf_err("max_type_info_count: %td\n", max_type_info_count);
 			Type *t = alloc_type_array(t_type_info, max_type_info_count);
-			LLVMValueRef g = LLVMAddGlobal(mod, lb_type(m, t), LB_TYPE_INFO_DATA_NAME);
+			LLVMValueRef g = LLVMAddGlobal(m->mod, lb_type(m, t), LB_TYPE_INFO_DATA_NAME);
 			LLVMSetInitializer(g, LLVMConstNull(lb_type(m, t)));
-			LLVMSetLinkage(g, LLVMInternalLinkage);
+			if (!USE_SEPARTE_MODULES) {
+				LLVMSetLinkage(g, LLVMInternalLinkage);
+			}
 
 			lbValue value = {};
 			value.value = g;
 			value.type = alloc_type_pointer(t);
-			lb_global_type_info_data = lb_addr(value);
+
+			lb_global_type_info_data_entity = alloc_entity_variable(nullptr, make_token_ident(LB_TYPE_INFO_DATA_NAME), t, EntityState_Resolved);
+			lb_add_entity(m, lb_global_type_info_data_entity, value);
 		}
 		{ // Type info member buffer
 			// NOTE(bill): Removes need for heap allocation by making it global memory
@@ -13856,7 +14734,7 @@ void lb_generate_code(lbGenerator *gen) {
 				{
 					char const *name = LB_TYPE_INFO_TYPES_NAME;
 					Type *t = alloc_type_array(t_type_info_ptr, count);
-					LLVMValueRef g = LLVMAddGlobal(mod, lb_type(m, t), name);
+					LLVMValueRef g = LLVMAddGlobal(m->mod, lb_type(m, t), name);
 					LLVMSetInitializer(g, LLVMConstNull(lb_type(m, t)));
 					LLVMSetLinkage(g, LLVMInternalLinkage);
 					lb_global_type_info_member_types = lb_addr({g, alloc_type_pointer(t)});
@@ -13865,7 +14743,7 @@ void lb_generate_code(lbGenerator *gen) {
 				{
 					char const *name = LB_TYPE_INFO_NAMES_NAME;
 					Type *t = alloc_type_array(t_string, count);
-					LLVMValueRef g = LLVMAddGlobal(mod, lb_type(m, t), name);
+					LLVMValueRef g = LLVMAddGlobal(m->mod, lb_type(m, t), name);
 					LLVMSetInitializer(g, LLVMConstNull(lb_type(m, t)));
 					LLVMSetLinkage(g, LLVMInternalLinkage);
 					lb_global_type_info_member_names = lb_addr({g, alloc_type_pointer(t)});
@@ -13873,7 +14751,7 @@ void lb_generate_code(lbGenerator *gen) {
 				{
 					char const *name = LB_TYPE_INFO_OFFSETS_NAME;
 					Type *t = alloc_type_array(t_uintptr, count);
-					LLVMValueRef g = LLVMAddGlobal(mod, lb_type(m, t), name);
+					LLVMValueRef g = LLVMAddGlobal(m->mod, lb_type(m, t), name);
 					LLVMSetInitializer(g, LLVMConstNull(lb_type(m, t)));
 					LLVMSetLinkage(g, LLVMInternalLinkage);
 					lb_global_type_info_member_offsets = lb_addr({g, alloc_type_pointer(t)});
@@ -13882,7 +14760,7 @@ void lb_generate_code(lbGenerator *gen) {
 				{
 					char const *name = LB_TYPE_INFO_USINGS_NAME;
 					Type *t = alloc_type_array(t_bool, count);
-					LLVMValueRef g = LLVMAddGlobal(mod, lb_type(m, t), name);
+					LLVMValueRef g = LLVMAddGlobal(m->mod, lb_type(m, t), name);
 					LLVMSetInitializer(g, LLVMConstNull(lb_type(m, t)));
 					LLVMSetLinkage(g, LLVMInternalLinkage);
 					lb_global_type_info_member_usings = lb_addr({g, alloc_type_pointer(t)});
@@ -13891,7 +14769,7 @@ void lb_generate_code(lbGenerator *gen) {
 				{
 					char const *name = LB_TYPE_INFO_TAGS_NAME;
 					Type *t = alloc_type_array(t_string, count);
-					LLVMValueRef g = LLVMAddGlobal(mod, lb_type(m, t), name);
+					LLVMValueRef g = LLVMAddGlobal(m->mod, lb_type(m, t), name);
 					LLVMSetInitializer(g, LLVMConstNull(lb_type(m, t)));
 					LLVMSetLinkage(g, LLVMInternalLinkage);
 					lb_global_type_info_member_tags = lb_addr({g, alloc_type_pointer(t)});
@@ -13931,13 +14809,8 @@ void lb_generate_code(lbGenerator *gen) {
 		}
 	}
 
-	struct GlobalVariable {
-		lbValue var;
-		lbValue init;
-		DeclInfo *decl;
-		bool is_initialized;
-	};
-	auto global_variables = array_make<GlobalVariable>(permanent_allocator(), 0, global_variable_max_count);
+
+	auto global_variables = array_make<lbGlobalVariable>(permanent_allocator(), 0, global_variable_max_count);
 
 	for_array(i, info->variable_init_order) {
 		DeclInfo *d = info->variable_init_order[i];
@@ -13960,8 +14833,9 @@ void lb_generate_code(lbGenerator *gen) {
 		bool is_foreign = e->Variable.is_foreign;
 		bool is_export  = e->Variable.is_export;
 
-		String name = lb_get_entity_name(m, e);
 
+		lbModule *m = &gen->default_module;
+		String name = lb_get_entity_name(m, e);
 
 		lbValue g = {};
 		g.value = LLVMAddGlobal(m->mod, lb_type(m, e->type), alloc_cstring(permanent_allocator(), name));
@@ -13985,6 +14859,7 @@ void lb_generate_code(lbGenerator *gen) {
 			LLVMSetThreadLocalMode(g.value, mode);
 		}
 		if (is_foreign) {
+			LLVMSetLinkage(g.value, LLVMExternalLinkage);
 			LLVMSetExternallyInitialized(g.value, true);
 			lb_add_foreign_library_path(m, e->Variable.foreign_library);
 		} else {
@@ -13993,13 +14868,15 @@ void lb_generate_code(lbGenerator *gen) {
 		if (is_export) {
 			LLVMSetLinkage(g.value, LLVMDLLExportLinkage);
 			LLVMSetDLLStorageClass(g.value, LLVMDLLExportStorageClass);
+		} else {
+			if (USE_SEPARTE_MODULES) {
+				LLVMSetLinkage(g.value, LLVMExternalLinkage);
+			} else {
+				LLVMSetLinkage(g.value, LLVMInternalLinkage);
+			}
 		}
 
-		if (e->flags & EntityFlag_Static) {
-			LLVMSetLinkage(g.value, LLVMInternalLinkage);
-		}
-
-		GlobalVariable var = {};
+		lbGlobalVariable var = {};
 		var.var = g;
 		var.decl = decl;
 
@@ -14026,13 +14903,14 @@ void lb_generate_code(lbGenerator *gen) {
 		lb_add_entity(m, e, g);
 		lb_add_member(m, name, g);
 
+
 		if (m->debug_builder) {
 			String global_name = e->token.string;
 			if (global_name.len != 0 && global_name != "_") {
 				LLVMMetadataRef llvm_file = lb_get_llvm_metadata(m, e->file);
 				LLVMMetadataRef llvm_scope = llvm_file;
 
-				LLVMBool local_to_unit = e->flags & EntityFlag_Static;
+				LLVMBool local_to_unit = LLVMGetLinkage(g.value) == LLVMInternalLinkage;
 
 				LLVMMetadataRef llvm_expr = LLVMDIBuilderCreateExpression(m->debug_builder, nullptr, 0);
 				LLVMMetadataRef llvm_decl = nullptr;
@@ -14096,6 +14974,10 @@ void lb_generate_code(lbGenerator *gen) {
 			continue;
 		}
 
+		lbModule *m = &gen->default_module;
+		if (USE_SEPARTE_MODULES) {
+			m = lb_pkg_module(gen, e->pkg);
+		}
 
 		String mangled_name = lb_get_entity_name(m, e);
 
@@ -14113,450 +14995,209 @@ void lb_generate_code(lbGenerator *gen) {
 	}
 
 
-	TIME_SECTION("LLVM Registry Initializtion");
-
-	LLVMPassRegistryRef pass_registry = LLVMGetGlobalPassRegistry();
-
-	LLVMPassManagerRef default_function_pass_manager = LLVMCreateFunctionPassManagerForModule(mod);
-	LLVMPassManagerRef function_pass_manager_minimal = LLVMCreateFunctionPassManagerForModule(mod);
-	LLVMPassManagerRef function_pass_manager_size = LLVMCreateFunctionPassManagerForModule(mod);
-	LLVMPassManagerRef function_pass_manager_speed = LLVMCreateFunctionPassManagerForModule(mod);
-	defer (LLVMDisposePassManager(default_function_pass_manager));
-	defer (LLVMDisposePassManager(function_pass_manager_minimal));
-	defer (LLVMDisposePassManager(function_pass_manager_size));
-	defer (LLVMDisposePassManager(function_pass_manager_speed));
-
-	LLVMInitializeFunctionPassManager(default_function_pass_manager);
-	LLVMInitializeFunctionPassManager(function_pass_manager_minimal);
-	LLVMInitializeFunctionPassManager(function_pass_manager_size);
-	LLVMInitializeFunctionPassManager(function_pass_manager_speed);
-
-	lb_populate_function_pass_manager(default_function_pass_manager, false, build_context.optimization_level);
-	lb_populate_function_pass_manager_specific(function_pass_manager_minimal, 0);
-	lb_populate_function_pass_manager_specific(function_pass_manager_size,    1);
-	lb_populate_function_pass_manager_specific(function_pass_manager_speed,   2);
-
-	LLVMFinalizeFunctionPassManager(default_function_pass_manager);
-	LLVMFinalizeFunctionPassManager(function_pass_manager_minimal);
-	LLVMFinalizeFunctionPassManager(function_pass_manager_size);
-	LLVMFinalizeFunctionPassManager(function_pass_manager_speed);
-
-
-	LLVMPassManagerRef default_function_pass_manager_without_memcpy = LLVMCreateFunctionPassManagerForModule(mod);
-	defer (LLVMDisposePassManager(default_function_pass_manager_without_memcpy));
-	LLVMInitializeFunctionPassManager(default_function_pass_manager_without_memcpy);
-	lb_populate_function_pass_manager(default_function_pass_manager_without_memcpy, true, build_context.optimization_level);
-	LLVMFinalizeFunctionPassManager(default_function_pass_manager_without_memcpy);
-
 	TIME_SECTION("LLVM Runtime Type Information Creation");
+	lbProcedure *startup_type_info = lb_create_startup_type_info(default_module);
 
-	lbProcedure *startup_type_info = nullptr;
-	lbProcedure *startup_runtime = nullptr;
-	{ // Startup Type Info
-		Type *params  = alloc_type_tuple();
-		Type *results = alloc_type_tuple();
-
-		Type *proc_type = alloc_type_proc(nullptr, nullptr, 0, nullptr, 0, false, ProcCC_CDecl);
-
-		lbProcedure *p = lb_create_dummy_procedure(m, str_lit(LB_STARTUP_TYPE_INFO_PROC_NAME), proc_type);
-		p->is_startup = true;
-		startup_type_info = p;
-
-		lb_begin_procedure_body(p);
-
-		lb_setup_type_info_data(p);
-
-		lb_end_procedure_body(p);
-
-		if (!m->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
-			gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %s\n", "main");
-			LLVMDumpValue(p->value);
-			gb_printf_err("\n\n\n\n");
-			LLVMVerifyFunction(p->value, LLVMAbortProcessAction);
-		}
-
-		LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
-	}
 	TIME_SECTION("LLVM Runtime Startup Creation (Global Variables)");
-	{ // Startup Runtime
-		Type *params  = alloc_type_tuple();
-		Type *results = alloc_type_tuple();
-
-		Type *proc_type = alloc_type_proc(nullptr, nullptr, 0, nullptr, 0, false, ProcCC_CDecl);
-
-		lbProcedure *p = lb_create_dummy_procedure(m, str_lit(LB_STARTUP_RUNTIME_PROC_NAME), proc_type);
-		p->is_startup = true;
-		startup_runtime = p;
+	lbProcedure *startup_runtime = lb_create_startup_runtime(default_module, startup_type_info, global_variables);
 
-		lb_begin_procedure_body(p);
 
-
-		LLVMBuildCall2(p->builder, LLVMGetElementType(lb_type(m, startup_type_info->type)), startup_type_info->value, nullptr, 0, "");
-
-		for_array(i, global_variables) {
-			auto *var = &global_variables[i];
-			if (var->is_initialized) {
+	TIME_SECTION("LLVM Procedure Generation");
+	for_array(j, gen->modules.entries) {
+		lbModule *m = gen->modules.entries[j].value;
+		for_array(i, m->procedures_to_generate) {
+			lbProcedure *p = m->procedures_to_generate[i];
+			if (p->is_done) {
 				continue;
 			}
-
-			Entity *e = var->decl->entity;
-			GB_ASSERT(e->kind == Entity_Variable);
-
-			if (var->decl->init_expr != nullptr)  {
-				// gb_printf_err("%s\n", expr_to_string(var->decl->init_expr));
-				lbValue init = lb_build_expr(p, var->decl->init_expr);
-				LLVMValueKind value_kind = LLVMGetValueKind(init.value);
-				// gb_printf_err("%s %d\n", LLVMPrintValueToString(init.value));
-
-				if (lb_is_const_or_global(init)) {
-					if (!var->is_initialized) {
-						LLVMSetInitializer(var->var.value, init.value);
-						var->is_initialized = true;
-						continue;
-					}
-				} else {
-					var->init = init;
-				}
-			}
-
-			if (var->init.value != nullptr) {
-				GB_ASSERT(!var->is_initialized);
-				Type *t = type_deref(var->var.type);
-
-				if (is_type_any(t)) {
-					// NOTE(bill): Edge case for 'any' type
-					Type *var_type = default_type(var->init.type);
-					lbAddr g = lb_add_global_generated(m, var_type, var->init);
-					lb_addr_store(p, g, var->init);
-					lbValue gp = lb_addr_get_ptr(p, g);
-
-					lbValue data = lb_emit_struct_ep(p, var->var, 0);
-					lbValue ti   = lb_emit_struct_ep(p, var->var, 1);
-					lb_emit_store(p, data, lb_emit_conv(p, gp, t_rawptr));
-					lb_emit_store(p, ti,   lb_type_info(m, var_type));
-				} else {
-					LLVMTypeRef pvt = LLVMTypeOf(var->var.value);
-					LLVMTypeRef vt = LLVMGetElementType(pvt);
-					lbValue src0 = lb_emit_conv(p, var->init, t);
-					LLVMValueRef src = OdinLLVMBuildTransmute(p, src0.value, vt);
-					LLVMValueRef dst = var->var.value;
-					LLVMBuildStore(p->builder, src, dst);
-				}
-
-				var->is_initialized = true;
+			if (p->body != nullptr) { // Build Procedure
+				m->curr_procedure = p;
+				lb_begin_procedure_body(p);
+				lb_build_stmt(p, p->body);
+				lb_end_procedure_body(p);
+				p->is_done = true;
+				m->curr_procedure = nullptr;
+			}
+			lb_end_procedure(p);
+
+			// Add Flags
+			if (p->body != nullptr) {
+				if (p->name == "memcpy" || p->name == "memmove" ||
+				    p->name == "runtime.mem_copy" || p->name == "mem_copy_non_overlapping" ||
+				    string_starts_with(p->name, str_lit("llvm.memcpy")) ||
+				    string_starts_with(p->name, str_lit("llvm.memmove"))) {
+					p->flags |= lbProcedureFlag_WithoutMemcpyPass;
+				}
+			}
+
+			if (!m->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
+				gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %.*s\n", LIT(p->name));
+				LLVMDumpValue(p->value);
+				gb_printf_err("\n\n\n\n");
+				String filepath_ll = lb_filepath_ll_for_module(m);
+				if (LLVMPrintModuleToFile(m->mod, cast(char const *)filepath_ll.text, &llvm_error)) {
+					gb_printf_err("LLVM Error: %s\n", llvm_error);
+				}
+				LLVMVerifyFunction(p->value, LLVMPrintMessageAction);
+				gb_exit(1);
 			}
 		}
-
-
-		lb_end_procedure_body(p);
-
-		if (!m->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
-			gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %s\n", "main");
-			LLVMDumpValue(p->value);
-			gb_printf_err("\n\n\n\n");
-			LLVMVerifyFunction(p->value, LLVMAbortProcessAction);
-		}
-
-		LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
-
-		/*{
-			LLVMValueRef last_instr = LLVMGetLastInstruction(p->decl_block->block);
-			for (LLVMValueRef instr = LLVMGetFirstInstruction(p->decl_block->block);
-			     instr != last_instr;
-			     instr = LLVMGetNextInstruction(instr)) {
-				if (LLVMIsAAllocaInst(instr)) {
-					LLVMTypeRef type = LLVMGetAllocatedType(instr);
-					LLVMValueRef sz_val = LLVMSizeOf(type);
-					GB_ASSERT(LLVMIsConstant(sz_val));
-					gb_printf_err(">> 0x%p\n", sz_val);
-					LLVMTypeRef sz_type = LLVMTypeOf(sz_val);
-					gb_printf_err(">> %s\n", LLVMPrintTypeToString(sz_type));
-					unsigned long long sz = LLVMConstIntGetZExtValue(sz_val);
-					// long long sz = LLVMConstIntGetSExtValue(sz_val);
-					gb_printf_err(">> %ll\n", sz);
-				}
-			}
-		}*/
 	}
 
-	String filepath_ll = concatenate_strings(permanent_allocator(), gen->output_base, STR_LIT(".ll"));
 
-	TIME_SECTION("LLVM Procedure Generation");
-	for_array(i, m->procedures_to_generate) {
-		lbProcedure *p = m->procedures_to_generate[i];
-		if (p->is_done) {
-			continue;
-		}
-		if (p->body != nullptr) { // Build Procedure
-			m->curr_procedure = p;
-			lb_begin_procedure_body(p);
-			lb_build_stmt(p, p->body);
-			lb_end_procedure_body(p);
-			p->is_done = true;
-			m->curr_procedure = nullptr;
-		}
-		lb_end_procedure(p);
-
-		// Add Flags
-		if (p->body != nullptr) {
-			if (p->name == "memcpy" || p->name == "memmove" ||
-			    p->name == "runtime.mem_copy" || p->name == "mem_copy_non_overlapping" ||
-			    string_starts_with(p->name, str_lit("llvm.memcpy")) ||
-			    string_starts_with(p->name, str_lit("llvm.memmove"))) {
-				p->flags |= lbProcedureFlag_WithoutMemcpyPass;
-			}
-		}
+	if (!(build_context.build_mode == BuildMode_DynamicLibrary && !has_dll_main)) {
+		TIME_SECTION("LLVM main");
+		lb_create_main_procedure(default_module, startup_runtime);
+	}
 
-		if (!m->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
-			gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %.*s\n", LIT(p->name));
-			LLVMDumpValue(p->value);
-			gb_printf_err("\n\n\n\n");
-			if (LLVMPrintModuleToFile(mod, cast(char const *)filepath_ll.text, &llvm_error)) {
-				gb_printf_err("LLVM Error: %s\n", llvm_error);
+	if (build_context.ODIN_DEBUG) {
+		TIME_SECTION("LLVM Debug Info Complete Types and Finalize");
+		for_array(j, gen->modules.entries) {
+			lbModule *m = gen->modules.entries[j].value;
+			if (m->debug_builder != nullptr) {
+				lb_debug_complete_types(m);
+				LLVMDIBuilderFinalize(m->debug_builder);
 			}
-			LLVMVerifyFunction(p->value, LLVMPrintMessageAction);
-			gb_exit(1);
 		}
 	}
 
 
-	if (!(build_context.build_mode == BuildMode_DynamicLibrary && !has_dll_main)) {
-		TIME_SECTION("LLVM DLL main");
-
-
-		Type *params  = alloc_type_tuple();
-		Type *results = alloc_type_tuple();
-
-		String name = str_lit("main");
-		if (build_context.metrics.os == TargetOs_windows && build_context.metrics.arch == TargetArch_386) {
-			name = str_lit("mainCRTStartup");
-		} else {
-			array_init(&params->Tuple.variables, permanent_allocator(), 2);
-			params->Tuple.variables[0] = alloc_entity_param(nullptr, make_token_ident("argc"), t_i32, false, true);
-			params->Tuple.variables[1] = alloc_entity_param(nullptr, make_token_ident("argv"), alloc_type_pointer(t_cstring), false, true);
-		}
-
-		array_init(&results->Tuple.variables, permanent_allocator(), 1);
-		results->Tuple.variables[0] = alloc_entity_param(nullptr, make_token_ident("_"),   t_i32, false, true);
-
-		Type *proc_type = alloc_type_proc(nullptr,
-			params, params->Tuple.variables.count,
-			results, results->Tuple.variables.count, false, ProcCC_CDecl);
+	TIME_SECTION("LLVM Function Pass");
+	for_array(i, gen->modules.entries) {
+		lbModule *m = gen->modules.entries[i].value;
 
+		lb_llvm_function_pass_worker_proc(m);
+	}
 
-		lbProcedure *p = lb_create_dummy_procedure(m, name, proc_type);
-		p->is_startup = true;
+	TIME_SECTION("LLVM Module Pass");
 
-		lb_begin_procedure_body(p);
+	for_array(i, gen->modules.entries) {
+		lbModule *m = gen->modules.entries[i].value;
 
-		LLVMBuildCall2(p->builder, LLVMGetElementType(lb_type(m, startup_runtime->type)), startup_runtime->value, nullptr, 0, "");
+		auto wd = gb_alloc_item(permanent_allocator(), lbLLVMModulePassWorkerData);
+		wd->m = m;
+		wd->target_machine = target_machines[i];
 
-		if (build_context.command_kind == Command_test) {
-			Type *t_Internal_Test = find_type_in_pkg(m->info, str_lit("testing"), str_lit("Internal_Test"));
-			Type *array_type = alloc_type_array(t_Internal_Test, m->info->testing_procedures.count);
-			Type *slice_type = alloc_type_slice(t_Internal_Test);
-			lbAddr all_tests_array_addr = lb_add_global_generated(p->module, array_type, {});
-			lbValue all_tests_array = lb_addr_get_ptr(p, all_tests_array_addr);
+		lb_llvm_module_pass_worker_proc(wd);
+	}
 
-			LLVMTypeRef lbt_Internal_Test = lb_type(m, t_Internal_Test);
 
-			LLVMValueRef indices[2] = {};
-			indices[0] = LLVMConstInt(lb_type(m, t_i32), 0, false);
+	llvm_error = nullptr;
+	defer (LLVMDisposeMessage(llvm_error));
 
-			for_array(i, m->info->testing_procedures) {
-				Entity *testing_proc = m->info->testing_procedures[i];
-				String name = testing_proc->token.string;
-				lbValue *found = map_get(&m->values, hash_entity(testing_proc));
-				GB_ASSERT(found != nullptr);
+	LLVMCodeGenFileType code_gen_file_type = LLVMObjectFile;
+	if (build_context.build_mode == BuildMode_Assembly) {
+		code_gen_file_type = LLVMAssemblyFile;
+	}
 
-				String pkg_name = {};
-				if (testing_proc->pkg != nullptr) {
-					pkg_name = testing_proc->pkg->name;
+	for_array(j, gen->modules.entries) {
+		lbModule *m = gen->modules.entries[j].value;
+		if (LLVMVerifyModule(m->mod, LLVMReturnStatusAction, &llvm_error)) {
+			gb_printf_err("LLVM Error:\n%s\n", llvm_error);
+			if (build_context.keep_temp_files) {
+				TIME_SECTION("LLVM Print Module to File");
+				String filepath_ll = lb_filepath_ll_for_module(m);
+				if (LLVMPrintModuleToFile(m->mod, cast(char const *)filepath_ll.text, &llvm_error)) {
+					gb_printf_err("LLVM Error: %s\n", llvm_error);
+					gb_exit(1);
+					return;
 				}
-				lbValue v_pkg  = lb_find_or_add_entity_string(m, pkg_name);
-				lbValue v_name = lb_find_or_add_entity_string(m, name);
-				lbValue v_proc = *found;
-
-				indices[1] = LLVMConstInt(lb_type(m, t_int), i, false);
-
-				LLVMValueRef vals[3] = {};
-				vals[0] = v_pkg.value;
-				vals[1] = v_name.value;
-				vals[2] = v_proc.value;
-				GB_ASSERT(LLVMIsConstant(vals[0]));
-				GB_ASSERT(LLVMIsConstant(vals[1]));
-				GB_ASSERT(LLVMIsConstant(vals[2]));
-
-				LLVMValueRef dst = LLVMConstInBoundsGEP(all_tests_array.value, indices, gb_count_of(indices));
-				LLVMValueRef src = llvm_const_named_struct(lbt_Internal_Test, vals, gb_count_of(vals));
-
-				LLVMBuildStore(p->builder, src, dst);
 			}
+			gb_exit(1);
+			return;
+		}
+	}
+	llvm_error = nullptr;
+	if (build_context.keep_temp_files ||
+	    build_context.build_mode == BuildMode_LLVM_IR) {
+		TIME_SECTION("LLVM Print Module to File");
 
-			lbAddr all_tests_slice = lb_add_local_generated(p, slice_type, true);
-			lb_fill_slice(p, all_tests_slice,
-			              lb_array_elem(p, all_tests_array),
-			              lb_const_int(m, t_int, m->info->testing_procedures.count));
+		for_array(j, gen->modules.entries) {
+			lbModule *m = gen->modules.entries[j].value;
 
+			if (lb_is_module_empty(m)) {
+				continue;
+			}
 
-			lbValue runner = lb_find_package_value(m, str_lit("testing"), str_lit("runner"));
+			String filepath_ll = lb_filepath_ll_for_module(m);
+			if (LLVMPrintModuleToFile(m->mod, cast(char const *)filepath_ll.text, &llvm_error)) {
+				gb_printf_err("LLVM Error: %s\n", llvm_error);
+				gb_exit(1);
+				return;
+			}
+			array_add(&gen->output_temp_paths, filepath_ll);
 
-			auto args = array_make<lbValue>(heap_allocator(), 1);
-			args[0] = lb_addr_load(p, all_tests_slice);
-			lb_emit_call(p, runner, args);
-		} else {
-			lbValue *found = map_get(&m->values, hash_entity(entry_point));
-			GB_ASSERT(found != nullptr);
-			lb_emit_call(p, *found, {});
 		}
-
-		LLVMBuildRet(p->builder, LLVMConstInt(lb_type(m, t_i32), 0, false));
-
-		lb_end_procedure_body(p);
-
-		if (!m->debug_builder && LLVMVerifyFunction(p->value, LLVMReturnStatusAction)) {
-			gb_printf_err("LLVM CODE GEN FAILED FOR PROCEDURE: %s\n", "main");
-			LLVMDumpValue(p->value);
-			gb_printf_err("\n\n\n\n");
-			LLVMVerifyFunction(p->value, LLVMAbortProcessAction);
+		if (build_context.build_mode == BuildMode_LLVM_IR) {
+			gb_exit(0);
+			return;
 		}
-
-		LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
 	}
 
 
-	if (m->debug_builder != nullptr) {
-		TIME_SECTION("LLVM Debug Info Complete Types");
-		lb_debug_complete_types(m);
+	TIME_SECTION("LLVM Add Foreign Library Paths");
 
+	for_array(j, gen->modules.entries) {
+		lbModule *m = gen->modules.entries[j].value;
+		for_array(i, m->info->required_foreign_imports_through_force) {
+			Entity *e = m->info->required_foreign_imports_through_force[i];
+			lb_add_foreign_library_path(m, e);
+		}
 
-		TIME_SECTION("LLVM Print Module to File");
-		if (LLVMPrintModuleToFile(mod, cast(char const *)filepath_ll.text, &llvm_error)) {
-			gb_printf_err("LLVM Error: %s\n", llvm_error);
-			gb_exit(1);
-			return;
+		if (lb_is_module_empty(m)) {
+			continue;
 		}
-		TIME_SECTION("LLVM Debug Info Builder Finalize");
-		LLVMDIBuilderFinalize(m->debug_builder);
 	}
 
+	TIME_SECTION("LLVM Object Generation");
 
-	TIME_SECTION("LLVM Function Pass");
-	{
-		for_array(i, m->procedures_to_generate) {
-			lbProcedure *p = m->procedures_to_generate[i];
-			if (p->body != nullptr) { // Build Procedure
-				if (p->flags & lbProcedureFlag_WithoutMemcpyPass) {
-					LLVMRunFunctionPassManager(default_function_pass_manager_without_memcpy, p->value);
-				} else {
-					if (p->entity && p->entity->kind == Entity_Procedure) {
-						switch (p->entity->Procedure.optimization_mode) {
-						case ProcedureOptimizationMode_None:
-						case ProcedureOptimizationMode_Minimal:
-							LLVMRunFunctionPassManager(function_pass_manager_minimal, p->value);
-							break;
-						case ProcedureOptimizationMode_Size:
-							LLVMRunFunctionPassManager(function_pass_manager_size, p->value);
-							break;
-						case ProcedureOptimizationMode_Speed:
-							LLVMRunFunctionPassManager(function_pass_manager_speed, p->value);
-							break;
-						default:
-							LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
-							break;
-						}
-					} else {
-						LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
-					}
-				}
+	if (do_threading) {
+		for_array(j, gen->modules.entries) {
+			lbModule *m = gen->modules.entries[j].value;
+			if (lb_is_module_empty(m)) {
+				continue;
 			}
-		}
 
-		for_array(i, m->equal_procs.entries) {
-			lbProcedure *p = m->equal_procs.entries[i].value;
-			LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
-		}
-		for_array(i, m->hasher_procs.entries) {
-			lbProcedure *p = m->hasher_procs.entries[i].value;
-			LLVMRunFunctionPassManager(default_function_pass_manager, p->value);
-		}
-	}
+			String filepath_ll = lb_filepath_ll_for_module(m);
+			String filepath_obj = lb_filepath_obj_for_module(m);
+			array_add(&gen->output_object_paths, filepath_obj);
+			array_add(&gen->output_temp_paths, filepath_ll);
 
-	TIME_SECTION("LLVM Module Pass");
+			auto *wd = gb_alloc_item(heap_allocator(), lbLLVMEmitWorker);
+			wd->target_machine = target_machines[j];
+			wd->code_gen_file_type = code_gen_file_type;
+			wd->filepath_obj = filepath_obj;
+			wd->m = m;
+			thread_pool_add_task(&lb_thread_pool, lb_llvm_emit_worker_proc, wd);
+		}
 
-	LLVMPassManagerRef module_pass_manager = LLVMCreatePassManager();
-	defer (LLVMDisposePassManager(module_pass_manager));
-	lb_populate_module_pass_manager(target_machine, module_pass_manager, build_context.optimization_level);
+		thread_pool_start(&lb_thread_pool);
+		thread_pool_wait_to_process(&lb_thread_pool);
+	} else {
+		for_array(j, gen->modules.entries) {
+			lbModule *m = gen->modules.entries[j].value;
+			if (lb_is_module_empty(m)) {
+				continue;
+			}
 
-	LLVMRunPassManager(module_pass_manager, mod);
+			String filepath_obj = lb_filepath_obj_for_module(m);
+			array_add(&gen->output_object_paths, filepath_obj);
 
-	llvm_error = nullptr;
-	defer (LLVMDisposeMessage(llvm_error));
+			String short_name = remove_directory_from_path(filepath_obj);
+			gbString section_name = gb_string_make(heap_allocator(), "LLVM Generate Object: ");
+			section_name = gb_string_append_length(section_name, short_name.text, short_name.len);
 
-	String filepath_obj = {};
-	LLVMCodeGenFileType code_gen_file_type = LLVMObjectFile;
+			TIME_SECTION_WITH_LEN(section_name, gb_string_length(section_name));
 
-	if (build_context.build_mode == BuildMode_Assembly) {
-		filepath_obj = concatenate_strings(permanent_allocator(), gen->output_base, STR_LIT(".S"));
-		code_gen_file_type = LLVMAssemblyFile;
-	} else {
-		switch (build_context.metrics.os) {
-		case TargetOs_windows:
-			filepath_obj = concatenate_strings(permanent_allocator(), gen->output_base, STR_LIT(".obj"));
-			break;
-		case TargetOs_darwin:
-		case TargetOs_linux:
-		case TargetOs_essence:
-			filepath_obj = concatenate_strings(permanent_allocator(), gen->output_base, STR_LIT(".o"));
-			break;
-		case TargetOs_js:
-			filepath_obj = concatenate_strings(permanent_allocator(), gen->output_base, STR_LIT(".wasm-obj"));
-			break;
-		}
-	}
-
-	if (LLVMVerifyModule(mod, LLVMReturnStatusAction, &llvm_error)) {
-		gb_printf_err("LLVM Error:\n%s\n", llvm_error);
-		if (build_context.keep_temp_files) {
-			TIME_SECTION("LLVM Print Module to File");
-			if (LLVMPrintModuleToFile(mod, cast(char const *)filepath_ll.text, &llvm_error)) {
+			if (LLVMTargetMachineEmitToFile(target_machines[j], m->mod, cast(char *)filepath_obj.text, code_gen_file_type, &llvm_error)) {
 				gb_printf_err("LLVM Error: %s\n", llvm_error);
 				gb_exit(1);
 				return;
 			}
 		}
-		gb_exit(1);
-		return;
-	}
-	llvm_error = nullptr;
-	if (build_context.keep_temp_files ||
-	    build_context.build_mode == BuildMode_LLVM_IR) {
-		TIME_SECTION("LLVM Print Module to File");
-		if (LLVMPrintModuleToFile(mod, cast(char const *)filepath_ll.text, &llvm_error)) {
-			gb_printf_err("LLVM Error: %s\n", llvm_error);
-			gb_exit(1);
-			return;
-		}
-		if (build_context.build_mode == BuildMode_LLVM_IR) {
-			gb_exit(0);
-			return;
-		}
 	}
 
-	TIME_SECTION("LLVM Object Generation");
 
-	if (LLVMTargetMachineEmitToFile(target_machine, mod, cast(char *)filepath_obj.text, code_gen_file_type, &llvm_error)) {
-		gb_printf_err("LLVM Error: %s\n", llvm_error);
-		gb_exit(1);
-		return;
-	}
-
-	array_add(&gen->output_object_paths, filepath_obj);
-
-	for_array(i, m->info->required_foreign_imports_through_force) {
-		Entity *e = m->info->required_foreign_imports_through_force[i];
-		lb_add_foreign_library_path(m, e);
-	}
 
 #undef TIME_SECTION
 }
diff --git a/src/llvm_backend.hpp b/src/llvm_backend.hpp
index e8811a91e..b35c042ee 100644
--- a/src/llvm_backend.hpp
+++ b/src/llvm_backend.hpp
@@ -85,11 +85,10 @@ struct lbModule {
 	LLVMModuleRef mod;
 	LLVMContextRef ctx;
 
-	u64 state_flags;
+	struct lbGenerator *gen;
 
 	CheckerInfo *info;
-
-	gbMutex mutex;
+	AstPackage *pkg; // associated
 
 	Map<LLVMTypeRef> types; // Key: Type *
 	Map<Type *> llvm_types; // Key: LLVMTypeRef
@@ -109,8 +108,6 @@ struct lbModule {
 	Map<lbProcedure *> equal_procs; // Key: Type *
 	Map<lbProcedure *> hasher_procs; // Key: Type *
 
-	u32 global_array_index;
-	u32 global_generated_index;
 	u32 nested_type_name_guid;
 
 	Array<lbProcedure *> procedures_to_generate;
@@ -126,12 +123,22 @@ struct lbModule {
 };
 
 struct lbGenerator {
-	lbModule module;
 	CheckerInfo *info;
 
+	gbMutex mutex;
+
 	Array<String> output_object_paths;
+	Array<String> output_temp_paths;
 	String   output_base;
 	String   output_name;
+	Map<lbModule *> modules; // Key: AstPackage *
+	Map<lbModule *> modules_through_ctx; // Key: LLVMContextRef *
+	lbModule default_module;
+
+	Map<lbProcedure *> anonymous_proc_lits; // Key: Ast *
+
+	gbAtomic32 global_array_index;
+	gbAtomic32 global_generated_index;
 };
 
 
@@ -210,6 +217,7 @@ enum lbProcedureFlag : u32 {
 
 struct lbProcedure {
 	u32 flags;
+	u16 state_flags;
 
 	lbProcedure *parent;
 	Array<lbProcedure *> children;
@@ -268,9 +276,10 @@ String lb_mangle_name(lbModule *m, Entity *e);
 String lb_get_entity_name(lbModule *m, Entity *e, String name = {});
 
 LLVMAttributeRef lb_create_enum_attribute(LLVMContextRef ctx, char const *name, u64 value=0);
+LLVMAttributeRef lb_create_enum_attribute_with_type(LLVMContextRef ctx, char const *name, LLVMTypeRef type);
 void lb_add_proc_attribute_at_index(lbProcedure *p, isize index, char const *name, u64 value);
 void lb_add_proc_attribute_at_index(lbProcedure *p, isize index, char const *name);
-lbProcedure *lb_create_procedure(lbModule *module, Entity *entity);
+lbProcedure *lb_create_procedure(lbModule *module, Entity *entity, bool ignore_body=false);
 void lb_end_procedure(lbProcedure *p);
 
 
@@ -381,6 +390,8 @@ lbValue lb_gen_map_header(lbProcedure *p, lbValue map_val_ptr, Type *map_type);
 lbValue lb_gen_map_hash(lbProcedure *p, lbValue key, Type *key_type);
 void    lb_insert_dynamic_map_key_and_value(lbProcedure *p, lbAddr addr, Type *map_type, lbValue map_key, lbValue map_value, Ast *node);
 
+lbValue lb_find_procedure_value_from_entity(lbModule *m, Entity *e);
+lbValue lb_find_value_from_entity(lbModule *m, Entity *e);
 
 void lb_store_type_case_implicit(lbProcedure *p, Ast *clause, lbValue value);
 lbAddr lb_store_range_stmt_val(lbProcedure *p, Ast *stmt_val, lbValue value);
@@ -472,6 +483,7 @@ lbCallingConventionKind const lb_calling_convention_map[ProcCC_MAX] = {
 	lbCallingConvention_X86_FastCall, // ProcCC_FastCall,
 
 	lbCallingConvention_C,            // ProcCC_None,
+	lbCallingConvention_C,            // ProcCC_Naked,
 	lbCallingConvention_C,            // ProcCC_InlineAsm,
 };
 
diff --git a/src/llvm_backend_opt.cpp b/src/llvm_backend_opt.cpp
index 3b268dffa..213005f8f 100644
--- a/src/llvm_backend_opt.cpp
+++ b/src/llvm_backend_opt.cpp
@@ -1,7 +1,25 @@
-void lb_populate_function_pass_manager(LLVMPassManagerRef fpm, bool ignore_memcpy_pass, i32 optimization_level);
+void lb_populate_function_pass_manager(lbModule *m, LLVMPassManagerRef fpm, bool ignore_memcpy_pass, i32 optimization_level);
 void lb_add_function_simplifcation_passes(LLVMPassManagerRef mpm, i32 optimization_level);
 void lb_populate_module_pass_manager(LLVMTargetMachineRef target_machine, LLVMPassManagerRef mpm, i32 optimization_level);
-void lb_populate_function_pass_manager_specific(LLVMPassManagerRef fpm, i32 optimization_level);
+void lb_populate_function_pass_manager_specific(lbModule *m, LLVMPassManagerRef fpm, i32 optimization_level);
+
+LLVMBool lb_must_preserve_predicate_callback(LLVMValueRef value, void *user_data) {
+	lbModule *m = cast(lbModule *)user_data;
+	if (m == nullptr) {
+		return false;
+	}
+	if (value == nullptr) {
+		return false;
+	}
+	return LLVMIsAAllocaInst(value) != nullptr;
+}
+
+void lb_add_must_preserve_predicate_pass(lbModule *m, LLVMPassManagerRef fpm, i32 optimization_level) {
+	if (false && optimization_level == 0 && m->debug_builder) {
+		// LLVMAddInternalizePassWithMustPreservePredicate(fpm, m, lb_must_preserve_predicate_callback);
+	}
+}
+
 
 void lb_basic_populate_function_pass_manager(LLVMPassManagerRef fpm) {
 	LLVMAddPromoteMemoryToRegisterPass(fpm);
@@ -15,11 +33,13 @@ void lb_basic_populate_function_pass_manager(LLVMPassManagerRef fpm) {
 	LLVMAddCFGSimplificationPass(fpm);
 }
 
-void lb_populate_function_pass_manager(LLVMPassManagerRef fpm, bool ignore_memcpy_pass, i32 optimization_level) {
+void lb_populate_function_pass_manager(lbModule *m, LLVMPassManagerRef fpm, bool ignore_memcpy_pass, i32 optimization_level) {
 	// NOTE(bill): Treat -opt:3 as if it was -opt:2
 	// TODO(bill): Determine which opt definitions should exist in the first place
 	optimization_level = gb_clamp(optimization_level, 0, 2);
 
+	lb_add_must_preserve_predicate_pass(m, fpm, optimization_level);
+
 	if (ignore_memcpy_pass) {
 		lb_basic_populate_function_pass_manager(fpm);
 		return;
@@ -57,11 +77,13 @@ void lb_populate_function_pass_manager(LLVMPassManagerRef fpm, bool ignore_memcp
 #endif
 }
 
-void lb_populate_function_pass_manager_specific(LLVMPassManagerRef fpm, i32 optimization_level) {
+void lb_populate_function_pass_manager_specific(lbModule *m, LLVMPassManagerRef fpm, i32 optimization_level) {
 	// NOTE(bill): Treat -opt:3 as if it was -opt:2
 	// TODO(bill): Determine which opt definitions should exist in the first place
 	optimization_level = gb_clamp(optimization_level, 0, 2);
 
+	lb_add_must_preserve_predicate_pass(m, fpm, optimization_level);
+
 	if (optimization_level == 0) {
 		LLVMAddMemCpyOptPass(fpm);
 		lb_basic_populate_function_pass_manager(fpm);
@@ -226,3 +248,104 @@ void lb_populate_module_pass_manager(LLVMTargetMachineRef target_machine, LLVMPa
 
 	LLVMAddCFGSimplificationPass(mpm);
 }
+
+void lb_run_remove_dead_instruction_pass(lbProcedure *p) {
+	isize removal_count = 0;
+	isize pass_count = 0;
+	isize const max_pass_count = 10;
+	isize original_instruction_count = 0;
+	// Custom remove dead instruction pass
+	for (; pass_count < max_pass_count; pass_count++) {
+		bool was_dead_instructions = false;
+
+		// NOTE(bill): Iterate backwards
+		// reduces the number of passes as things later on will depend on things previously
+		for (LLVMBasicBlockRef block = LLVMGetLastBasicBlock(p->value);
+		     block != nullptr;
+		     block = LLVMGetPreviousBasicBlock(block)) {
+			// NOTE(bill): Iterate backwards
+			// reduces the number of passes as things later on will depend on things previously
+			for (LLVMValueRef instr = LLVMGetLastInstruction(block);
+			     instr != nullptr;
+			     /**/)  {
+			     	if (pass_count == 0) {
+			     		original_instruction_count += 1;
+			     	}
+
+				LLVMValueRef curr_instr = instr;
+				instr = LLVMGetPreviousInstruction(instr);
+
+				LLVMUseRef first_use = LLVMGetFirstUse(curr_instr);
+				if (first_use != nullptr)  {
+					continue;
+				}
+				if (LLVMTypeOf(curr_instr) == nullptr) {
+					continue;
+				}
+
+				// NOTE(bill): Explicit instructions are set here because some instructions could have side effects
+				switch (LLVMGetInstructionOpcode(curr_instr)) {
+				case LLVMFNeg:
+				case LLVMAdd:
+				case LLVMFAdd:
+				case LLVMSub:
+				case LLVMFSub:
+				case LLVMMul:
+				case LLVMFMul:
+				case LLVMUDiv:
+				case LLVMSDiv:
+				case LLVMFDiv:
+				case LLVMURem:
+				case LLVMSRem:
+				case LLVMFRem:
+				case LLVMShl:
+				case LLVMLShr:
+				case LLVMAShr:
+				case LLVMAnd:
+				case LLVMOr:
+				case LLVMXor:
+				case LLVMAlloca:
+				case LLVMLoad:
+				case LLVMGetElementPtr:
+				case LLVMTrunc:
+				case LLVMZExt:
+				case LLVMSExt:
+				case LLVMFPToUI:
+				case LLVMFPToSI:
+				case LLVMUIToFP:
+				case LLVMSIToFP:
+				case LLVMFPTrunc:
+				case LLVMFPExt:
+				case LLVMPtrToInt:
+				case LLVMIntToPtr:
+				case LLVMBitCast:
+				case LLVMAddrSpaceCast:
+				case LLVMICmp:
+				case LLVMFCmp:
+				case LLVMSelect:
+				case LLVMExtractElement:
+				case LLVMShuffleVector:
+				case LLVMExtractValue:
+					removal_count += 1;
+					LLVMInstructionEraseFromParent(curr_instr);
+					was_dead_instructions = true;
+					break;
+				}
+			}
+		}
+
+		if (!was_dead_instructions) {
+			break;
+		}
+	}
+}
+
+
+void lb_run_function_pass_manager(LLVMPassManagerRef fpm, lbProcedure *p) {
+	LLVMRunFunctionPassManager(fpm, p->value);
+	// NOTE(bill): LLVMAddDCEPass doesn't seem to be exported in the official DLL's for LLVM
+	// which means we cannot rely upon it
+	// This is also useful for read the .ll for debug purposes because a lot of instructions
+	// are not removed
+	lb_run_remove_dead_instruction_pass(p);
+}
diff --git a/src/main.cpp b/src/main.cpp
index 251616b56..d16a110e3 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -218,8 +218,19 @@ i32 linker_stage(lbGenerator *gen) {
 			add_path(find_result.vs_library_path);
 		}
 
-		for_array(i, gen->module.foreign_library_paths) {
-			String lib = gen->module.foreign_library_paths[i];
+		for_array(j, gen->modules.entries) {
+			lbModule *m = gen->modules.entries[j].value;
+			for_array(i, m->foreign_library_paths) {
+				String lib = m->foreign_library_paths[i];
+				GB_ASSERT(lib.len < gb_count_of(lib_str_buf)-1);
+				isize len = gb_snprintf(lib_str_buf, gb_size_of(lib_str_buf),
+				                        " \"%.*s\"", LIT(lib));
+				lib_str = gb_string_appendc(lib_str, lib_str_buf);
+			}
+		}
+
+		for_array(i, gen->default_module.foreign_library_paths) {
+			String lib = gen->default_module.foreign_library_paths[i];
 			GB_ASSERT(lib.len < gb_count_of(lib_str_buf)-1);
 			isize len = gb_snprintf(lib_str_buf, gb_size_of(lib_str_buf),
 			                        " \"%.*s\"", LIT(lib));
@@ -265,22 +276,22 @@ i32 linker_stage(lbGenerator *gen) {
 					LIT(build_context.resource_filepath)
 				);
 
-        if(result == 0) {
-          result = system_exec_command_line_app("msvc-link",
-            "\"%.*slink.exe\" %s \"%.*s.res\" -OUT:\"%.*s.%s\" %s "
-            "/nologo /incremental:no /opt:ref /subsystem:%s "
-            " %.*s "
-            " %.*s "
-            " %s "
-            "",
-            LIT(find_result.vs_exe_path), object_files, LIT(output_base), LIT(output_base), output_ext,
-            link_settings,
-            subsystem_str,
-            LIT(build_context.link_flags),
-            LIT(build_context.extra_linker_flags),
-            lib_str
-          );
-        }
+				if (result == 0) {
+					result = system_exec_command_line_app("msvc-link",
+						"\"%.*slink.exe\" %s \"%.*s.res\" -OUT:\"%.*s.%s\" %s "
+						"/nologo /incremental:no /opt:ref /subsystem:%s "
+						" %.*s "
+						" %.*s "
+						" %s "
+						"",
+						LIT(find_result.vs_exe_path), object_files, LIT(output_base), LIT(output_base), output_ext,
+						link_settings,
+						subsystem_str,
+						LIT(build_context.link_flags),
+						LIT(build_context.extra_linker_flags),
+						lib_str
+					  );
+				}
 			} else {
 				result = system_exec_command_line_app("msvc-link",
 					"\"%.*slink.exe\" %s -OUT:\"%.*s.%s\" %s "
@@ -327,8 +338,8 @@ i32 linker_stage(lbGenerator *gen) {
 		gbString lib_str = gb_string_make(heap_allocator(), "-L/");
 		defer (gb_string_free(lib_str));
 
-		for_array(i, gen->module.foreign_library_paths) {
-			String lib = gen->module.foreign_library_paths[i];
+		for_array(i, gen->default_module.foreign_library_paths) {
+			String lib = gen->default_module.foreign_library_paths[i];
 
 			// NOTE(zangent): Sometimes, you have to use -framework on MacOS.
 			//   This allows you to specify '-f' in a #foreign_system_library,
@@ -409,6 +420,11 @@ i32 linker_stage(lbGenerator *gen) {
 			#endif
 		}
 
+		if (build_context.metrics.os == TargetOs_linux) {
+			link_settings = gb_string_appendc(link_settings, "-no-pie ");
+		}
+
+
 		if (build_context.out_filepath.len > 0) {
 			//NOTE(thebirk): We have a custom -out arguments, so we should use the extension from that
 			isize pos = string_extension_position(build_context.out_filepath);
@@ -580,6 +596,7 @@ enum BuildFlagKind {
 	BuildFlag_NoCRT,
 	BuildFlag_NoEntryPoint,
 	BuildFlag_UseLLD,
+	BuildFlag_UseSeparateModules,
 	BuildFlag_Vet,
 	BuildFlag_VetExtra,
 	BuildFlag_UseLLVMApi,
@@ -587,6 +604,8 @@ enum BuildFlagKind {
 	BuildFlag_ExtraLinkerFlags,
 	BuildFlag_Microarch,
 
+	BuildFlag_TestName,
+
 	BuildFlag_DisallowDo,
 	BuildFlag_DefaultToNilAllocator,
 	BuildFlag_InsertSemicolon,
@@ -602,6 +621,7 @@ enum BuildFlagKind {
 
 	BuildFlag_IgnoreWarnings,
 	BuildFlag_WarningsAsErrors,
+	BuildFlag_VerboseErrors,
 
 #if defined(GB_SYSTEM_WINDOWS)
 	BuildFlag_IgnoreVsSearch,
@@ -698,6 +718,7 @@ bool parse_build_flags(Array<String> args) {
 	add_flag(&build_flags, BuildFlag_NoCRT,             str_lit("no-crt"),              BuildFlagParam_None, Command__does_build);
 	add_flag(&build_flags, BuildFlag_NoEntryPoint,      str_lit("no-entry-point"),      BuildFlagParam_None, Command__does_check &~ Command_test);
 	add_flag(&build_flags, BuildFlag_UseLLD,            str_lit("lld"),                 BuildFlagParam_None, Command__does_build);
+	add_flag(&build_flags, BuildFlag_UseSeparateModules,str_lit("use-separate-modules"),BuildFlagParam_None, Command__does_build);
 	add_flag(&build_flags, BuildFlag_Vet,               str_lit("vet"),                 BuildFlagParam_None, Command__does_check);
 	add_flag(&build_flags, BuildFlag_VetExtra,          str_lit("vet-extra"),           BuildFlagParam_None, Command__does_check);
 	add_flag(&build_flags, BuildFlag_UseLLVMApi,        str_lit("llvm-api"),            BuildFlagParam_None, Command__does_build);
@@ -705,6 +726,8 @@ bool parse_build_flags(Array<String> args) {
 	add_flag(&build_flags, BuildFlag_ExtraLinkerFlags,  str_lit("extra-linker-flags"),              BuildFlagParam_String, Command__does_build);
 	add_flag(&build_flags, BuildFlag_Microarch,         str_lit("microarch"),                       BuildFlagParam_String, Command__does_build);
 
+	add_flag(&build_flags, BuildFlag_TestName,         str_lit("test-name"),                       BuildFlagParam_String, Command_test);
+
 	add_flag(&build_flags, BuildFlag_DisallowDo,            str_lit("disallow-do"),              BuildFlagParam_None, Command__does_check);
 	add_flag(&build_flags, BuildFlag_DefaultToNilAllocator, str_lit("default-to-nil-allocator"), BuildFlagParam_None, Command__does_check);
 	add_flag(&build_flags, BuildFlag_InsertSemicolon,       str_lit("insert-semicolon"),         BuildFlagParam_None, Command__does_check);
@@ -719,6 +742,7 @@ bool parse_build_flags(Array<String> args) {
 
 	add_flag(&build_flags, BuildFlag_IgnoreWarnings,   str_lit("ignore-warnings"),    BuildFlagParam_None, Command_all);
 	add_flag(&build_flags, BuildFlag_WarningsAsErrors, str_lit("warnings-as-errors"), BuildFlagParam_None, Command_all);
+	add_flag(&build_flags, BuildFlag_VerboseErrors,    str_lit("verbose-errors"),     BuildFlagParam_None, Command_all);
 
 #if defined(GB_SYSTEM_WINDOWS)
 	add_flag(&build_flags, BuildFlag_IgnoreVsSearch, str_lit("ignore-vs-search"),  BuildFlagParam_None, Command__does_build);
@@ -1175,6 +1199,10 @@ bool parse_build_flags(Array<String> args) {
 							build_context.use_lld = true;
 							break;
 
+						case BuildFlag_UseSeparateModules:
+							build_context.use_separate_modules = true;
+							break;
+
 						case BuildFlag_Vet:
 							build_context.vet = true;
 							break;
@@ -1203,6 +1231,21 @@ bool parse_build_flags(Array<String> args) {
 							string_to_lower(&build_context.microarch);
 							break;
 
+						case BuildFlag_TestName:
+							GB_ASSERT(value.kind == ExactValue_String);
+							{
+								String name = value.value_string;
+								if (!string_is_valid_identifier(name)) {
+									gb_printf_err("Test name '%.*s' must be a valid identifier\n", LIT(name));
+									bad_flags = true;
+									break;
+								}
+								string_set_add(&build_context.test_names, name);
+
+								// NOTE(bill): Allow for multiple -test-name
+								continue;
+							}
+
 						case BuildFlag_DisallowDo:
 							build_context.disallow_do = true;
 							break;
@@ -1279,6 +1322,10 @@ bool parse_build_flags(Array<String> args) {
 							}
 							break;
 
+						case BuildFlag_VerboseErrors:
+							build_context.show_error_line = true;
+							break;
+
 					#if defined(GB_SYSTEM_WINDOWS)
 						case BuildFlag_IgnoreVsSearch:
 							GB_ASSERT(value.kind == ExactValue_Invalid);
@@ -1507,96 +1554,22 @@ void show_timings(Checker *c, Timings *t) {
 	}
 }
 
-void remove_temp_files(String output_base) {
+void remove_temp_files(lbGenerator *gen) {
 	if (build_context.keep_temp_files) return;
 
-	auto data = array_make<u8>(heap_allocator(), output_base.len + 30);
-	defer (array_free(&data));
-
-	isize n = output_base.len;
-	gb_memmove(data.data, output_base.text, n);
-#define EXT_REMOVE(s) do {                         \
-		gb_memmove(data.data+n, s, gb_size_of(s)); \
-		gb_file_remove(cast(char const *)data.data);     \
-	} while (0)
-	EXT_REMOVE(".ll");
-	EXT_REMOVE(".bc");
-	EXT_REMOVE("_memcpy_pass.bc");
-	if (build_context.build_mode != BuildMode_Object && !build_context.keep_object_files) {
-	#if defined(GB_SYSTEM_WINDOWS)
-		EXT_REMOVE(".obj");
-		EXT_REMOVE(".res");
-	#else
-		EXT_REMOVE(".o");
-	#endif
+	for_array(i, gen->output_temp_paths) {
+		String path = gen->output_temp_paths[i];
+		gb_file_remove(cast(char const *)path.text);
 	}
 
-#undef EXT_REMOVE
-}
-
-
-
-
-i32 exec_llvm_opt(String output_base) {
-#if defined(GB_SYSTEM_WINDOWS)
-	// For more passes arguments: http://llvm.org/docs/Passes.html
-
-  return system_exec_command_line_app("llvm-opt",
-		"\"%.*sbin/opt\" \"%.*s.ll\" -o \"%.*s_memcpy_pass.bc\" -memcpyopt"
-		"",
-		LIT(build_context.ODIN_ROOT),
-		LIT(output_base), LIT(output_base))
-
-  || system_exec_command_line_app("llvm-opt",
-		"\"%.*sbin/opt\" \"%.*s_memcpy_pass.bc\" -o \"%.*s.bc\" %.*s "
-		"",
-		LIT(build_context.ODIN_ROOT),
-		LIT(output_base), LIT(output_base),
-		LIT(build_context.opt_flags));
-#else
-	// NOTE(zangent): This is separate because it seems that LLVM tools are packaged
-	//   with the Windows version, while they will be system-provided on MacOS and GNU/Linux
-
-  return system_exec_command_line_app("llvm-opt",
-    "opt \"%.*s.ll\" -o \"%.*s_memcpy_pass.bc\" -memcpyopt"
-    "",
-    LIT(output_base), LIT(output_base))
-
-	|| system_exec_command_line_app("llvm-opt",
-		"opt \"%.*s_memcpy_pass.bc\" -o \"%.*s.bc\" %.*s "
-		"",
-		LIT(output_base), LIT(output_base),
-		LIT(build_context.opt_flags));
-#endif
+	if (build_context.build_mode != BuildMode_Object && !build_context.keep_object_files) {
+		for_array(i, gen->output_object_paths) {
+			String path = gen->output_object_paths[i];
+			gb_file_remove(cast(char const *)path.text);
+		}
+	}
 }
 
-i32 exec_llvm_llc(String output_base) {
-	// For more arguments: http://llvm.org/docs/CommandGuide/llc.html
-#if defined(GB_SYSTEM_WINDOWS)
-	return system_exec_command_line_app("llvm-llc",
-		"\"%.*sbin\\llc\" \"%.*s.bc\" -filetype=obj -O%d "
-		"-o \"%.*s.obj\" "
-		"%.*s"
-		"",
-		LIT(build_context.ODIN_ROOT),
-		LIT(output_base),
-		build_context.optimization_level,
-		LIT(output_base),
-		LIT(build_context.llc_flags));
-#else
-	// NOTE(zangent): Linux / Unix is unfinished and not tested very well.
-	return system_exec_command_line_app("llc",
-		"llc \"%.*s.bc\" -filetype=obj -relocation-model=pic -O%d "
-		"%.*s "
-		"%s%.*s",
-		LIT(output_base),
-		build_context.optimization_level,
-		LIT(build_context.llc_flags),
-		build_context.cross_compiling ? "-mtriple=" : "",
-		cast(int)(build_context.cross_compiling ? build_context.metrics.target_triplet.len : 0),
-		build_context.metrics.target_triplet.text);
-#endif
-}
 
 void print_show_help(String const arg0, String const &command) {
 	print_usage_line(0, "%.*s is a tool for managing Odin source code", LIT(arg0));
@@ -1612,7 +1585,7 @@ void print_show_help(String const arg0, String const &command) {
 	} else if (command == "check") {
 		print_usage_line(1, "check     parse and type check .odin file");
 	} else if (command == "test") {
-		print_usage_line(1, "test      build ands runs 'test_*' procedures in the initial package");
+		print_usage_line(1, "test      build ands runs procedures with the attribute @(test) in the initial package");
 	} else if (command == "query") {
 		print_usage_line(1, "query     [experimental] parse, type check, and output a .json file containing information about the program");
 	} else if (command == "doc") {
@@ -1627,6 +1600,7 @@ void print_show_help(String const arg0, String const &command) {
 	bool doc = command == "doc";
 	bool build = command == "build";
 	bool run_or_build = command == "run" || command == "build" || command == "test";
+	bool test_only = command == "test";
 	bool check_only = command == "check";
 	bool check = run_or_build || command == "check";
 
@@ -1720,6 +1694,11 @@ void print_show_help(String const arg0, String const &command) {
 		print_usage_line(3, "-build-mode:shared    Build as a dynamically linked library");
 		print_usage_line(3, "-build-mode:obj       Build as an object file");
 		print_usage_line(3, "-build-mode:object    Build as an object file");
+		print_usage_line(3, "-build-mode:assembly  Build as an object file");
+		print_usage_line(3, "-build-mode:assembler Build as an assembly file");
+		print_usage_line(3, "-build-mode:asm       Build as an assembly file");
+		print_usage_line(3, "-build-mode:llvm-ir   Build as an LLVM IR file");
+		print_usage_line(3, "-build-mode:llvm      Build as an LLVM IR file");
 		print_usage_line(0, "");
 	}
 
@@ -1746,9 +1725,16 @@ void print_show_help(String const arg0, String const &command) {
 		print_usage_line(2, "Disables automatic linking with the C Run Time");
 		print_usage_line(0, "");
 
-		print_usage_line(1, "-use-lld");
+		print_usage_line(1, "-lld");
 		print_usage_line(2, "Use the LLD linker rather than the default");
 		print_usage_line(0, "");
+
+		print_usage_line(1, "-use-separate-modules");
+		print_usage_line(1, "[EXPERIMENTAL]");
+		print_usage_line(2, "The backend generates multiple build units which are then linked together");
+		print_usage_line(2, "Normally, a single build unit is generated for a standard project");
+		print_usage_line(0, "");
+
 	}
 
 	if (check) {
@@ -1776,6 +1762,12 @@ void print_show_help(String const arg0, String const &command) {
 		}
 	}
 
+	if (test_only) {
+		print_usage_line(1, "-test-name:<string>");
+		print_usage_line(2, "Run specific test only by name");
+		print_usage_line(0, "");
+	}
+
 	if (run_or_build) {
 		print_usage_line(1, "-extra-linker-flags:<string>");
 		print_usage_line(2, "Adds extra linker specific flags in a string");
@@ -1943,7 +1935,7 @@ int main(int arg_count, char const **arg_ptr) {
 
 	Timings *timings = &global_timings;
 
-	timings_init(timings, str_lit("Total Time"), 128);
+	timings_init(timings, str_lit("Total Time"), 2048);
 	defer (timings_destroy(timings));
 
 	arena_init(&permanent_arena, heap_allocator());
@@ -1967,7 +1959,7 @@ int main(int arg_count, char const **arg_ptr) {
 
 	map_init(&build_context.defined_values, heap_allocator());
 	build_context.extra_packages.allocator = heap_allocator();
-
+	string_set_init(&build_context.test_names, heap_allocator());
 
 	Array<String> args = setup_args(arg_count, arg_ptr);
 
@@ -2190,6 +2182,9 @@ int main(int arg_count, char const **arg_ptr) {
 	case BuildMode_DynamicLibrary:
 		i32 result = linker_stage(&gen);
 		if (result != 0) {
+			if (build_context.show_timings) {
+				show_timings(&checker, timings);
+			}
 			return 1;
 		}
 		break;
@@ -2199,7 +2194,7 @@ int main(int arg_count, char const **arg_ptr) {
 		show_timings(&checker, timings);
 	}
 
-	remove_temp_files(gen.output_base);
+	remove_temp_files(&gen);
 
 	if (run_output) {
 	#if defined(GB_SYSTEM_WINDOWS)
diff --git a/src/parser.cpp b/src/parser.cpp
index a7e4c9162..a5180b4dd 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -1,110 +1,4 @@
-Token ast_token(Ast *node) {
-	switch (node->kind) {
-	case Ast_Ident:          return node->Ident.token;
-	case Ast_Implicit:       return node->Implicit;
-	case Ast_Undef:          return node->Undef;
-	case Ast_BasicLit:       return node->BasicLit.token;
-	case Ast_BasicDirective: return node->BasicDirective.token;
-	case Ast_ProcGroup:      return node->ProcGroup.token;
-	case Ast_ProcLit:        return ast_token(node->ProcLit.type);
-	case Ast_CompoundLit:
-		if (node->CompoundLit.type != nullptr) {
-			return ast_token(node->CompoundLit.type);
-		}
-		return node->CompoundLit.open;
-
-	case Ast_TagExpr:       return node->TagExpr.token;
-	case Ast_BadExpr:       return node->BadExpr.begin;
-	case Ast_UnaryExpr:     return node->UnaryExpr.op;
-	case Ast_BinaryExpr:    return ast_token(node->BinaryExpr.left);
-	case Ast_ParenExpr:     return node->ParenExpr.open;
-	case Ast_CallExpr:      return ast_token(node->CallExpr.proc);
-	case Ast_SelectorExpr:
-		if (node->SelectorExpr.selector != nullptr) {
-			return ast_token(node->SelectorExpr.selector);
-		}
-		return node->SelectorExpr.token;
-	case Ast_SelectorCallExpr:
-		if (node->SelectorCallExpr.expr != nullptr) {
-			return ast_token(node->SelectorCallExpr.expr);
-		}
-		return node->SelectorCallExpr.token;
-	case Ast_ImplicitSelectorExpr:
-		if (node->ImplicitSelectorExpr.selector != nullptr) {
-			return ast_token(node->ImplicitSelectorExpr.selector);
-		}
-		return node->ImplicitSelectorExpr.token;
-	case Ast_IndexExpr:          return node->IndexExpr.open;
-	case Ast_SliceExpr:          return node->SliceExpr.open;
-	case Ast_Ellipsis:           return node->Ellipsis.token;
-	case Ast_FieldValue:         return node->FieldValue.eq;
-	case Ast_DerefExpr:          return node->DerefExpr.op;
-	case Ast_TernaryExpr:        return ast_token(node->TernaryExpr.cond);
-	case Ast_TernaryIfExpr:      return ast_token(node->TernaryIfExpr.x);
-	case Ast_TernaryWhenExpr:    return ast_token(node->TernaryWhenExpr.x);
-	case Ast_TypeAssertion:      return ast_token(node->TypeAssertion.expr);
-	case Ast_TypeCast:           return node->TypeCast.token;
-	case Ast_AutoCast:           return node->AutoCast.token;
-	case Ast_InlineAsmExpr:      return node->InlineAsmExpr.token;
-
-	case Ast_BadStmt:            return node->BadStmt.begin;
-	case Ast_EmptyStmt:          return node->EmptyStmt.token;
-	case Ast_ExprStmt:           return ast_token(node->ExprStmt.expr);
-	case Ast_TagStmt:            return node->TagStmt.token;
-	case Ast_AssignStmt:         return node->AssignStmt.op;
-	case Ast_BlockStmt:          return node->BlockStmt.open;
-	case Ast_IfStmt:             return node->IfStmt.token;
-	case Ast_WhenStmt:           return node->WhenStmt.token;
-	case Ast_ReturnStmt:         return node->ReturnStmt.token;
-	case Ast_ForStmt:            return node->ForStmt.token;
-	case Ast_RangeStmt:          return node->RangeStmt.token;
-	case Ast_UnrollRangeStmt:    return node->UnrollRangeStmt.unroll_token;
-	case Ast_CaseClause:         return node->CaseClause.token;
-	case Ast_SwitchStmt:         return node->SwitchStmt.token;
-	case Ast_TypeSwitchStmt:     return node->TypeSwitchStmt.token;
-	case Ast_DeferStmt:          return node->DeferStmt.token;
-	case Ast_BranchStmt:         return node->BranchStmt.token;
-	case Ast_UsingStmt:          return node->UsingStmt.token;
-
-	case Ast_BadDecl:            return node->BadDecl.begin;
-	case Ast_Label:              return node->Label.token;
-
-	case Ast_ValueDecl:          return ast_token(node->ValueDecl.names[0]);
-	case Ast_PackageDecl:        return node->PackageDecl.token;
-	case Ast_ImportDecl:         return node->ImportDecl.token;
-	case Ast_ForeignImportDecl:  return node->ForeignImportDecl.token;
-
-	case Ast_ForeignBlockDecl:   return node->ForeignBlockDecl.token;
-
-	case Ast_Attribute:
-		return node->Attribute.token;
-
-	case Ast_Field:
-		if (node->Field.names.count > 0) {
-			return ast_token(node->Field.names[0]);
-		}
-		return ast_token(node->Field.type);
-	case Ast_FieldList:
-		return node->FieldList.token;
-
-	case Ast_TypeidType:       return node->TypeidType.token;
-	case Ast_HelperType:       return node->HelperType.token;
-	case Ast_DistinctType:     return node->DistinctType.token;
-	case Ast_PolyType:         return node->PolyType.token;
-	case Ast_ProcType:         return node->ProcType.token;
-	case Ast_RelativeType:     return ast_token(node->RelativeType.tag);
-	case Ast_PointerType:      return node->PointerType.token;
-	case Ast_ArrayType:        return node->ArrayType.token;
-	case Ast_DynamicArrayType: return node->DynamicArrayType.token;
-	case Ast_StructType:       return node->StructType.token;
-	case Ast_UnionType:        return node->UnionType.token;
-	case Ast_EnumType:         return node->EnumType.token;
-	case Ast_BitSetType:       return node->BitSetType.token;
-	case Ast_MapType:          return node->MapType.token;
-	}
-
-	return empty_token;
-}
+#include "parser_pos.cpp"
 
 Token token_end_of_line(AstFile *f, Token tok) {
 	u8 const *start = f->tokenizer.start + tok.pos.offset;
@@ -116,6 +10,48 @@ Token token_end_of_line(AstFile *f, Token tok) {
 	return tok;
 }
 
+gbString get_file_line_as_string(TokenPos const &pos, i32 *offset_) {
+	AstFile *file = get_ast_file_from_id(pos.file_id);
+	if (file == nullptr) {
+		return nullptr;
+	}
+	isize offset = pos.offset;
+
+	u8 *start = file->tokenizer.start;
+	u8 *end = file->tokenizer.end;
+	isize len = end-start;
+	if (len < offset) {
+		return nullptr;
+	}
+
+	u8 *pos_offset = start+offset;
+
+	u8 *line_start = pos_offset;
+	u8 *line_end  = pos_offset;
+	while (line_start >= start) {
+		if (*line_start == '\n') {
+			line_start += 1;
+			break;
+		}
+		line_start -= 1;
+	}
+
+	while (line_end < end) {
+		if (*line_end == '\n') {
+			line_end -= 1;
+			break;
+		}
+		line_end += 1;
+	}
+	String the_line = make_string(line_start, line_end-line_start);
+	the_line = string_trim_whitespace(the_line);
+
+	if (offset_) *offset_ = cast(i32)(pos_offset - the_line.text);
+
+	return gb_string_make_length(heap_allocator(), the_line.text, the_line.len);
+}
+
+
 
 isize ast_node_size(AstKind kind) {
 	return align_formula_isize(gb_size_of(AstCommonStuff) + ast_variant_sizes[kind], gb_align_of(void *));
@@ -241,11 +177,6 @@ Ast *clone_ast(Ast *node) {
 		n->FieldValue.value = clone_ast(n->FieldValue.value);
 		break;
 
-	case Ast_TernaryExpr:
-		n->TernaryExpr.cond = clone_ast(n->TernaryExpr.cond);
-		n->TernaryExpr.x    = clone_ast(n->TernaryExpr.x);
-		n->TernaryExpr.y    = clone_ast(n->TernaryExpr.y);
-		break;
 	case Ast_TernaryIfExpr:
 		n->TernaryIfExpr.x    = clone_ast(n->TernaryIfExpr.x);
 		n->TernaryIfExpr.cond = clone_ast(n->TernaryIfExpr.cond);
@@ -438,12 +369,15 @@ Ast *clone_ast(Ast *node) {
 
 void error(Ast *node, char const *fmt, ...) {
 	Token token = {};
+	TokenPos end_pos = {};
 	if (node != nullptr) {
 		token = ast_token(node);
+		end_pos = ast_end_pos(node);
 	}
+
 	va_list va;
 	va_start(va, fmt);
-	error_va(token, fmt, va);
+	error_va(token.pos, end_pos, fmt, va);
 	va_end(va);
 	if (node != nullptr && node->file != nullptr) {
 		node->file->error_count += 1;
@@ -457,7 +391,7 @@ void error_no_newline(Ast *node, char const *fmt, ...) {
 	}
 	va_list va;
 	va_start(va, fmt);
-	error_no_newline_va(token, fmt, va);
+	error_no_newline_va(token.pos, fmt, va);
 	va_end(va);
 	if (node != nullptr && node->file != nullptr) {
 		node->file->error_count += 1;
@@ -465,16 +399,28 @@ void error_no_newline(Ast *node, char const *fmt, ...) {
 }
 
 void warning(Ast *node, char const *fmt, ...) {
+	Token token = {};
+	TokenPos end_pos = {};
+	if (node != nullptr) {
+		token = ast_token(node);
+		end_pos = ast_end_pos(node);
+	}
 	va_list va;
 	va_start(va, fmt);
-	warning_va(ast_token(node), fmt, va);
+	warning_va(token.pos, end_pos, fmt, va);
 	va_end(va);
 }
 
 void syntax_error(Ast *node, char const *fmt, ...) {
+	Token token = {};
+	TokenPos end_pos = {};
+	if (node != nullptr) {
+		token = ast_token(node);
+		end_pos = ast_end_pos(node);
+	}
 	va_list va;
 	va_start(va, fmt);
-	syntax_error_va(ast_token(node), fmt, va);
+	syntax_error_va(token.pos, end_pos, fmt, va);
 	va_end(va);
 	if (node != nullptr && node->file != nullptr) {
 		node->file->error_count += 1;
@@ -646,7 +592,7 @@ Ast *ast_basic_lit(AstFile *f, Token basic_lit) {
 	return result;
 }
 
-Ast *ast_basic_directive(AstFile *f, Token token, String name) {
+Ast *ast_basic_directive(AstFile *f, Token token, Token name) {
 	Ast *result = alloc_ast_node(f, Ast_BasicDirective);
 	result->BasicDirective.token = token;
 	result->BasicDirective.name = name;
@@ -698,13 +644,6 @@ Ast *ast_compound_lit(AstFile *f, Ast *type, Array<Ast *> const &elems, Token op
 }
 
 
-Ast *ast_ternary_expr(AstFile *f, Ast *cond, Ast *x, Ast *y) {
-	Ast *result = alloc_ast_node(f, Ast_TernaryExpr);
-	result->TernaryExpr.cond = cond;
-	result->TernaryExpr.x = x;
-	result->TernaryExpr.y = y;
-	return result;
-}
 Ast *ast_ternary_if_expr(AstFile *f, Ast *x, Ast *cond, Ast *y) {
 	Ast *result = alloc_ast_node(f, Ast_TernaryIfExpr);
 	result->TernaryIfExpr.x = x;
@@ -1357,6 +1296,7 @@ Token expect_token_after(AstFile *f, TokenKind kind, char const *msg) {
 bool is_token_range(TokenKind kind) {
 	switch (kind) {
 	case Token_Ellipsis:
+	case Token_RangeFull:
 	case Token_RangeHalf:
 		return true;
 	}
@@ -1587,6 +1527,10 @@ void expect_semicolon(AstFile *f, Ast *s) {
 		return;
 	}
 
+	if (f->curr_token.kind == Token_EOF) {
+		return;
+	}
+
 	if (s != nullptr) {
 		bool insert_semi = (f->tokenizer.flags & TokenizerFlag_InsertSemicolon) != 0;
 		if (insert_semi) {
@@ -2007,35 +1951,28 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 		Token name = expect_token(f, Token_Ident);
 		if (name.string == "type") {
 			return ast_helper_type(f, token, parse_type(f));
-		} /* else if (name.string == "no_deferred") {
-			operand = parse_expr(f, false);
-			if (unparen_expr(operand)->kind != Ast_CallExpr) {
-				syntax_error(operand, "#no_deferred can only be applied to procedure calls");
-				operand = ast_bad_expr(f, token, f->curr_token);
-			}
-			operand->state_flags |= StateFlag_no_deferred;
-		} */ else if (name.string == "file") {
-			return ast_basic_directive(f, token, name.string);
-		} else if (name.string == "line") { return ast_basic_directive(f, token, name.string);
-		} else if (name.string == "procedure") { return ast_basic_directive(f, token, name.string);
-		} else if (name.string == "caller_location") { return ast_basic_directive(f, token, name.string);
+		} else if (name.string == "file") {
+			return ast_basic_directive(f, token, name);
+		} else if (name.string == "line") { return ast_basic_directive(f, token, name);
+		} else if (name.string == "procedure") { return ast_basic_directive(f, token, name);
+		} else if (name.string == "caller_location") { return ast_basic_directive(f, token, name);
 		} else if (name.string == "location") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			return parse_call_expr(f, tag);
 		} else if (name.string == "load") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			return parse_call_expr(f, tag);
 		} else if (name.string == "assert") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			return parse_call_expr(f, tag);
 		} else if (name.string == "defined") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			return parse_call_expr(f, tag);
 		} else if (name.string == "config") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			return parse_call_expr(f, tag);
 		} else if (name.string == "soa" || name.string == "simd") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			Ast *original_type = parse_type(f);
 			Ast *type = unparen_expr(original_type);
 			switch (type->kind) {
@@ -2047,7 +1984,7 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			}
 			return original_type;
 		} else if (name.string == "partial") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			Ast *original_type = parse_type(f);
 			Ast *type = unparen_expr(original_type);
 			switch (type->kind) {
@@ -2059,6 +1996,10 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			return original_type;
 		} else if (name.string == "bounds_check") {
 			Ast *operand = parse_expr(f, lhs);
+			if (operand == nullptr) {
+				syntax_error(token, "Invalid expresssion for #%.*s", LIT(name.string));
+				return nullptr;
+			}
 			operand->state_flags |= StateFlag_bounds_check;
 			if ((operand->state_flags & StateFlag_no_bounds_check) != 0) {
 				syntax_error(token, "#bounds_check and #no_bounds_check cannot be applied together");
@@ -2066,13 +2007,17 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			return operand;
 		} else if (name.string == "no_bounds_check") {
 			Ast *operand = parse_expr(f, lhs);
+			if (operand == nullptr) {
+				syntax_error(token, "Invalid expresssion for #%.*s", LIT(name.string));
+				return nullptr;
+			}
 			operand->state_flags |= StateFlag_no_bounds_check;
 			if ((operand->state_flags & StateFlag_bounds_check) != 0) {
 				syntax_error(token, "#bounds_check and #no_bounds_check cannot be applied together");
 			}
 			return operand;
 		} else if (name.string == "relative") {
-			Ast *tag = ast_basic_directive(f, token, name.string);
+			Ast *tag = ast_basic_directive(f, token, name);
 			tag = parse_call_expr(f, tag);
 			Ast *type = parse_type(f);
 			return ast_relative_type(f, tag, type);
@@ -2158,6 +2103,8 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			return type;
 		}
 
+		skip_possible_newline_for_literal(f);
+
 		if (allow_token(f, Token_Undef)) {
 			if (where_token.kind != Token_Invalid) {
 				syntax_error(where_token, "'where' clauses are not allowed on procedure literals without a defined body (replaced with ---)");
@@ -2170,6 +2117,14 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			body = parse_body(f);
 			f->curr_proc = curr_proc;
 
+			// Apply the tags directly to the body rather than the type
+			if (tags & ProcTag_no_bounds_check) {
+				body->state_flags |= StateFlag_no_bounds_check;
+			}
+			if (tags & ProcTag_bounds_check) {
+				body->state_flags |= StateFlag_bounds_check;
+			}
+
 			return ast_proc_lit(f, type, body, tags, where_token, where_clauses);
 		} else if (allow_token(f, Token_do)) {
 			Ast *curr_proc = f->curr_proc;
@@ -2317,7 +2272,7 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			f->expr_level = prev_level;
 		}
 
-
+		skip_possible_newline_for_literal(f);
 		Token open = expect_token_after(f, Token_OpenBrace, "struct");
 
 		isize name_count = 0;
@@ -2394,6 +2349,7 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 		}
 
 
+		skip_possible_newline_for_literal(f);
 		Token open = expect_token_after(f, Token_OpenBrace, "union");
 
 		while (f->curr_token.kind != Token_CloseBrace &&
@@ -2418,6 +2374,8 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 		if (f->curr_token.kind != Token_OpenBrace) {
 			base_type = parse_type(f);
 		}
+
+		skip_possible_newline_for_literal(f);
 		Token open = expect_token(f, Token_OpenBrace);
 
 		Array<Ast *> values = parse_element_list(f);
@@ -2509,6 +2467,7 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			}
 		}
 
+		skip_possible_newline_for_literal(f);
 		Token open = expect_token(f, Token_OpenBrace);
 		Ast *asm_string = parse_expr(f, false);
 		expect_token(f, Token_Comma);
@@ -2673,6 +2632,7 @@ Ast *parse_atom_expr(AstFile *f, Ast *operand, bool lhs) {
 
 			switch (f->curr_token.kind) {
 			case Token_Ellipsis:
+			case Token_RangeFull:
 			case Token_RangeHalf:
 				// NOTE(bill): Do not err yet
 			case Token_Colon:
@@ -2684,6 +2644,7 @@ Ast *parse_atom_expr(AstFile *f, Ast *operand, bool lhs) {
 
 			switch (f->curr_token.kind) {
 			case Token_Ellipsis:
+			case Token_RangeFull:
 			case Token_RangeHalf:
 				syntax_error(f->curr_token, "Expected a colon, not a range");
 				/* fallthrough */
@@ -2722,6 +2683,16 @@ Ast *parse_atom_expr(AstFile *f, Ast *operand, bool lhs) {
 			}
 			break;
 
+		case Token_Increment:
+		case Token_Decrement:
+			if (!lhs) {
+				Token token = advance_token(f);
+				syntax_error(token, "Postfix '%.*s' operator is not supported", LIT(token.string));
+			} else {
+				loop = false;
+			}
+			break;
+
 		default:
 			loop = false;
 			break;
@@ -2752,16 +2723,26 @@ Ast *parse_unary_expr(AstFile *f, bool lhs) {
 		return ast_auto_cast(f, token, expr);
 	}
 
+
 	case Token_Add:
 	case Token_Sub:
-	case Token_Not:
 	case Token_Xor:
-	case Token_And: {
+	case Token_And:
+	case Token_Not: {
 		Token token = advance_token(f);
 		Ast *expr = parse_unary_expr(f, lhs);
 		return ast_unary_expr(f, token, expr);
 	}
 
+	case Token_Increment:
+	case Token_Decrement: {
+		Token token = advance_token(f);
+		syntax_error(token, "Unary '%.*s' operator is not supported", LIT(token.string));
+		Ast *expr = parse_unary_expr(f, lhs);
+		return ast_unary_expr(f, token, expr);
+	}
+
+
 	case Token_Period: {
 		Token token = expect_token(f, Token_Period);
 		Ast *ident = parse_ident(f);
@@ -2790,6 +2771,7 @@ i32 token_precedence(AstFile *f, TokenKind t) {
 	case Token_when:
 		return 1;
 	case Token_Ellipsis:
+	case Token_RangeFull:
 	case Token_RangeHalf:
 		if (!f->allow_range) {
 			return 0;
@@ -2857,7 +2839,7 @@ Ast *parse_binary_expr(AstFile *f, bool lhs, i32 prec_in) {
 				Ast *x = parse_expr(f, lhs);
 				Token token_c = expect_token(f, Token_Colon);
 				Ast *y = parse_expr(f, lhs);
-				expr = ast_ternary_expr(f, cond, x, y);
+				expr = ast_ternary_if_expr(f, x, cond, y);
 			} else if (op.kind == Token_if) {
 				Ast *x = expr;
 				// Token_if
@@ -2979,7 +2961,7 @@ Ast *parse_foreign_block(AstFile *f, Token token) {
 	defer (f->in_foreign_block = prev_in_foreign_block);
 	f->in_foreign_block = true;
 
-
+	skip_possible_newline_for_literal(f);
 	open = expect_token(f, Token_OpenBrace);
 
 	while (f->curr_token.kind != Token_CloseBrace &&
@@ -3151,6 +3133,13 @@ Ast *parse_simple_stmt(AstFile *f, u32 flags) {
 		return ast_bad_stmt(f, token, f->curr_token);
 	}
 
+	switch (token.kind) {
+	case Token_Increment:
+	case Token_Decrement:
+		advance_token(f);
+		syntax_error(token, "Postfix '%.*s' statement is not supported", LIT(token.string));
+		break;
+	}
 
 
 	#if 0
@@ -3220,6 +3209,7 @@ ProcCallingConvention string_to_calling_convention(String s) {
 	if (s == "fastcall")    return ProcCC_FastCall;
 	if (s == "fast")        return ProcCC_FastCall;
 	if (s == "none")        return ProcCC_None;
+	if (s == "naked")       return ProcCC_Naked;
 	return ProcCC_Invalid;
 }
 
@@ -3896,12 +3886,6 @@ Ast *parse_return_stmt(AstFile *f) {
 
 	while (f->curr_token.kind != Token_Semicolon) {
 		Ast *arg = parse_expr(f, false);
-		// if (f->curr_token.kind == Token_Eq) {
-		// 	Token eq = expect_token(f, Token_Eq);
-		// 	Ast *value = parse_value(f);
-		// 	arg = ast_field_value(f, arg, value, eq);
-		// }
-
 		array_add(&results, arg);
 		if (f->curr_token.kind != Token_Comma ||
 		    f->curr_token.kind == Token_EOF) {
@@ -3966,7 +3950,7 @@ Ast *parse_for_stmt(AstFile *f) {
 			}
 		}
 
-		if (!is_range && allow_token(f, Token_Semicolon)) {
+		if (!is_range && parse_control_statement_semicolon_separator(f)) {
 			init = cond;
 			cond = nullptr;
 			if (f->curr_token.kind != Token_Semicolon) {
@@ -4022,7 +4006,7 @@ Ast *parse_case_clause(AstFile *f, bool is_type) {
 	}
 	f->allow_range = prev_allow_range;
 	f->allow_in_expr = prev_allow_in_expr;
-	expect_token(f, Token_Colon); // TODO(bill): Is this the best syntax?
+	expect_token(f, Token_Colon);
 	Array<Ast *> stmts = parse_stmt_list(f);
 
 	return ast_case_clause(f, token, list, stmts);
@@ -4332,6 +4316,16 @@ Ast *parse_unrolled_for_loop(AstFile *f, Token unroll_token) {
 	return ast_unroll_range_stmt(f, unroll_token, for_token, val0, val1, in_token, expr, body);
 }
 
+void parse_check_directive_for_empty_statement(Ast *s, Token const &name) {
+	if (s != nullptr && s->kind == Ast_EmptyStmt) {
+		if (s->EmptyStmt.token.string == "\n") {
+			syntax_error(name, "#%.*s cannot be followed by a newline", LIT(name.string));
+		} else {
+			syntax_error(name, "#%.*s cannot be applied to an empty statement ';'", LIT(name.string));
+		}
+	}
+}
+
 Ast *parse_stmt(AstFile *f) {
 	Ast *s = nullptr;
 	Token token = f->curr_token;
@@ -4438,6 +4432,7 @@ Ast *parse_stmt(AstFile *f) {
 
 		if (tag == "bounds_check") {
 			s = parse_stmt(f);
+			parse_check_directive_for_empty_statement(s, name);
 			s->state_flags |= StateFlag_bounds_check;
 			if ((s->state_flags & StateFlag_no_bounds_check) != 0) {
 				syntax_error(token, "#bounds_check and #no_bounds_check cannot be applied together");
@@ -4445,27 +4440,12 @@ Ast *parse_stmt(AstFile *f) {
 			return s;
 		} else if (tag == "no_bounds_check") {
 			s = parse_stmt(f);
+			parse_check_directive_for_empty_statement(s, name);
 			s->state_flags |= StateFlag_no_bounds_check;
 			if ((s->state_flags & StateFlag_bounds_check) != 0) {
 				syntax_error(token, "#bounds_check and #no_bounds_check cannot be applied together");
 			}
 			return s;
-		} else if (tag == "complete") {
-			s = parse_stmt(f);
-			switch (s->kind) {
-			case Ast_SwitchStmt:
-				s->SwitchStmt.partial = false;
-				syntax_warning(token, "#complete is now the default and has been replaced with its opposite: #partial");
-				break;
-			case Ast_TypeSwitchStmt:
-				s->TypeSwitchStmt.partial = false;
-				syntax_warning(token, "#complete is now the default and has been replaced with its opposite: #partial");
-				break;
-			default:
-				syntax_error(token, "#complete can only be applied to a switch statement");
-				break;
-			}
-			return s;
 		} else if (tag == "partial") {
 			s = parse_stmt(f);
 			switch (s->kind) {
@@ -4475,16 +4455,19 @@ Ast *parse_stmt(AstFile *f) {
 			case Ast_TypeSwitchStmt:
 				s->TypeSwitchStmt.partial = true;
 				break;
+			case Ast_EmptyStmt:
+				parse_check_directive_for_empty_statement(s, name);
+				break;
 			default:
 				syntax_error(token, "#partial can only be applied to a switch statement");
 				break;
 			}
 			return s;
 		} else if (tag == "assert") {
-			Ast *t = ast_basic_directive(f, hash_token, tag);
+			Ast *t = ast_basic_directive(f, hash_token, name);
 			return ast_expr_stmt(f, parse_call_expr(f, t));
 		} else if (tag == "panic") {
-			Ast *t = ast_basic_directive(f, hash_token, tag);
+			Ast *t = ast_basic_directive(f, hash_token, name);
 			return ast_expr_stmt(f, parse_call_expr(f, t));
 		} else if (name.string == "force_inline" ||
 		           name.string == "force_no_inline") {
@@ -4571,6 +4554,7 @@ ParseFileError init_ast_file(AstFile *f, String fullpath, TokenPos *err_pos) {
 	GB_ASSERT(f != nullptr);
 	f->fullpath = string_trim_whitespace(fullpath); // Just in case
 	set_file_path_string(f->id, fullpath);
+	set_ast_file_from_id(f->id, f);
 	if (!string_ends_with(f->fullpath, str_lit(".odin"))) {
 		return ParseFile_WrongExtension;
 	}
diff --git a/src/parser.hpp b/src/parser.hpp
index 8c2eadb46..89f714aaa 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -7,22 +7,21 @@ struct AstFile;
 struct AstPackage;
 
 enum AddressingMode {
-	Addressing_Invalid,       // invalid addressing mode
-	Addressing_NoValue,       // no value (void in C)
-	Addressing_Value,         // computed value (rvalue)
-	Addressing_Context,       // context value
-	Addressing_Variable,      // addressable variable (lvalue)
-	Addressing_Constant,      // constant
-	Addressing_Type,          // type
-	Addressing_Builtin,       // built-in procedure
-	Addressing_ProcGroup,     // procedure group (overloaded procedure)
-	Addressing_MapIndex,      // map index expression -
-	                          // 	lhs: acts like a Variable
-	                          // 	rhs: acts like OptionalOk
-	Addressing_OptionalOk,    // rhs: acts like a value with an optional boolean part (for existence check)
-	Addressing_SoaVariable,   // Struct-Of-Arrays indexed variable
-
-	Addressing_AtomOpAssign,  // Specialized for custom atom operations for assignments
+	Addressing_Invalid   = 0,    // invalid addressing mode
+	Addressing_NoValue   = 1,    // no value (void in C)
+	Addressing_Value     = 2,    // computed value (rvalue)
+	Addressing_Context   = 3,    // context value
+	Addressing_Variable  = 4,    // addressable variable (lvalue)
+	Addressing_Constant  = 5,    // constant
+	Addressing_Type      = 6,    // type
+	Addressing_Builtin   = 7,    // built-in procedure
+	Addressing_ProcGroup = 8,    // procedure group (overloaded procedure)
+	Addressing_MapIndex  = 9,    // map index expression -
+	                             // 	lhs: acts like a Variable
+	                             // 	rhs: acts like OptionalOk
+	Addressing_OptionalOk  = 10, // rhs: acts like a value with an optional boolean part (for existence check)
+	Addressing_SoaVariable = 11, // Struct-Of-Arrays indexed variable
+
 };
 
 struct TypeAndValue {
@@ -215,8 +214,9 @@ enum ProcCallingConvention {
 	ProcCC_FastCall = 5,
 
 	ProcCC_None = 6,
+	ProcCC_Naked = 7,
 
-	ProcCC_InlineAsm = 7,
+	ProcCC_InlineAsm = 8,
 
 	ProcCC_MAX,
 
@@ -286,8 +286,8 @@ char const *inline_asm_dialect_strings[InlineAsmDialect_COUNT] = {
 		Token token; \
 	}) \
 	AST_KIND(BasicDirective, "basic directive", struct { \
-		Token  token; \
-		String name; \
+		Token token; \
+		Token name; \
 	}) \
 	AST_KIND(Ellipsis,       "ellipsis", struct { \
 		Token    token; \
@@ -324,7 +324,7 @@ AST_KIND(_ExprBegin,  "",  bool) \
 	AST_KIND(ImplicitSelectorExpr, "implicit selector expression",    struct { Token token; Ast *selector; }) \
 	AST_KIND(SelectorCallExpr, "selector call expression",    struct { Token token; Ast *expr, *call; bool modified_call; }) \
 	AST_KIND(IndexExpr,    "index expression",       struct { Ast *expr, *index; Token open, close; }) \
-	AST_KIND(DerefExpr,    "dereference expression", struct { Token op; Ast *expr; }) \
+	AST_KIND(DerefExpr,    "dereference expression", struct { Ast *expr; Token op; }) \
 	AST_KIND(SliceExpr,    "slice expression", struct { \
 		Ast *expr; \
 		Token open, close; \
@@ -342,10 +342,15 @@ AST_KIND(_ExprBegin,  "",  bool) \
 		i32          builtin_id; \
 	}) \
 	AST_KIND(FieldValue,      "field value",              struct { Token eq; Ast *field, *value; }) \
-	AST_KIND(TernaryExpr,     "ternary expression",       struct { Ast *cond, *x, *y; }) \
 	AST_KIND(TernaryIfExpr,   "ternary if expression",    struct { Ast *x, *cond, *y; }) \
 	AST_KIND(TernaryWhenExpr, "ternary when expression",  struct { Ast *x, *cond, *y; }) \
-	AST_KIND(TypeAssertion, "type assertion",      struct { Ast *expr; Token dot; Ast *type; Type *type_hint; }) \
+	AST_KIND(TypeAssertion, "type assertion", struct { \
+		Ast *expr; \
+		Token dot; \
+		Ast *type; \
+		Type *type_hint; \
+		bool ignores[2]; \
+	}) \
 	AST_KIND(TypeCast,      "type cast",           struct { Token token; Ast *type, *expr; }) \
 	AST_KIND(AutoCast,      "auto_cast",           struct { Token token; Ast *expr; }) \
 	AST_KIND(InlineAsmExpr, "inline asm expression", struct { \
diff --git a/src/parser_pos.cpp b/src/parser_pos.cpp
new file mode 100644
index 000000000..c5ad89604
--- /dev/null
+++ b/src/parser_pos.cpp
@@ -0,0 +1,331 @@
+Token ast_token(Ast *node) {
+	switch (node->kind) {
+	case Ast_Ident:          return node->Ident.token;
+	case Ast_Implicit:       return node->Implicit;
+	case Ast_Undef:          return node->Undef;
+	case Ast_BasicLit:       return node->BasicLit.token;
+	case Ast_BasicDirective: return node->BasicDirective.token;
+	case Ast_ProcGroup:      return node->ProcGroup.token;
+	case Ast_ProcLit:        return ast_token(node->ProcLit.type);
+	case Ast_CompoundLit:
+		if (node->CompoundLit.type != nullptr) {
+			return ast_token(node->CompoundLit.type);
+		}
+		return node->CompoundLit.open;
+
+	case Ast_TagExpr:       return node->TagExpr.token;
+	case Ast_BadExpr:       return node->BadExpr.begin;
+	case Ast_UnaryExpr:     return node->UnaryExpr.op;
+	case Ast_BinaryExpr:    return ast_token(node->BinaryExpr.left);
+	case Ast_ParenExpr:     return node->ParenExpr.open;
+	case Ast_CallExpr:      return ast_token(node->CallExpr.proc);
+	case Ast_SelectorExpr:
+		if (node->SelectorExpr.selector != nullptr) {
+			return ast_token(node->SelectorExpr.selector);
+		}
+		return node->SelectorExpr.token;
+	case Ast_SelectorCallExpr:
+		if (node->SelectorCallExpr.expr != nullptr) {
+			return ast_token(node->SelectorCallExpr.expr);
+		}
+		return node->SelectorCallExpr.token;
+	case Ast_ImplicitSelectorExpr:
+		if (node->ImplicitSelectorExpr.selector != nullptr) {
+			return ast_token(node->ImplicitSelectorExpr.selector);
+		}
+		return node->ImplicitSelectorExpr.token;
+	case Ast_IndexExpr:          return node->IndexExpr.open;
+	case Ast_SliceExpr:          return node->SliceExpr.open;
+	case Ast_Ellipsis:           return node->Ellipsis.token;
+	case Ast_FieldValue:         return node->FieldValue.eq;
+	case Ast_DerefExpr:          return node->DerefExpr.op;
+	case Ast_TernaryIfExpr:      return ast_token(node->TernaryIfExpr.x);
+	case Ast_TernaryWhenExpr:    return ast_token(node->TernaryWhenExpr.x);
+	case Ast_TypeAssertion:      return ast_token(node->TypeAssertion.expr);
+	case Ast_TypeCast:           return node->TypeCast.token;
+	case Ast_AutoCast:           return node->AutoCast.token;
+	case Ast_InlineAsmExpr:      return node->InlineAsmExpr.token;
+
+	case Ast_BadStmt:            return node->BadStmt.begin;
+	case Ast_EmptyStmt:          return node->EmptyStmt.token;
+	case Ast_ExprStmt:           return ast_token(node->ExprStmt.expr);
+	case Ast_TagStmt:            return node->TagStmt.token;
+	case Ast_AssignStmt:         return node->AssignStmt.op;
+	case Ast_BlockStmt:          return node->BlockStmt.open;
+	case Ast_IfStmt:             return node->IfStmt.token;
+	case Ast_WhenStmt:           return node->WhenStmt.token;
+	case Ast_ReturnStmt:         return node->ReturnStmt.token;
+	case Ast_ForStmt:            return node->ForStmt.token;
+	case Ast_RangeStmt:          return node->RangeStmt.token;
+	case Ast_UnrollRangeStmt:    return node->UnrollRangeStmt.unroll_token;
+	case Ast_CaseClause:         return node->CaseClause.token;
+	case Ast_SwitchStmt:         return node->SwitchStmt.token;
+	case Ast_TypeSwitchStmt:     return node->TypeSwitchStmt.token;
+	case Ast_DeferStmt:          return node->DeferStmt.token;
+	case Ast_BranchStmt:         return node->BranchStmt.token;
+	case Ast_UsingStmt:          return node->UsingStmt.token;
+
+	case Ast_BadDecl:            return node->BadDecl.begin;
+	case Ast_Label:              return node->Label.token;
+
+	case Ast_ValueDecl:          return ast_token(node->ValueDecl.names[0]);
+	case Ast_PackageDecl:        return node->PackageDecl.token;
+	case Ast_ImportDecl:         return node->ImportDecl.token;
+	case Ast_ForeignImportDecl:  return node->ForeignImportDecl.token;
+
+	case Ast_ForeignBlockDecl:   return node->ForeignBlockDecl.token;
+
+	case Ast_Attribute:
+		return node->Attribute.token;
+
+	case Ast_Field:
+		if (node->Field.names.count > 0) {
+			return ast_token(node->Field.names[0]);
+		}
+		return ast_token(node->Field.type);
+	case Ast_FieldList:
+		return node->FieldList.token;
+
+	case Ast_TypeidType:       return node->TypeidType.token;
+	case Ast_HelperType:       return node->HelperType.token;
+	case Ast_DistinctType:     return node->DistinctType.token;
+	case Ast_PolyType:         return node->PolyType.token;
+	case Ast_ProcType:         return node->ProcType.token;
+	case Ast_RelativeType:     return ast_token(node->RelativeType.tag);
+	case Ast_PointerType:      return node->PointerType.token;
+	case Ast_ArrayType:        return node->ArrayType.token;
+	case Ast_DynamicArrayType: return node->DynamicArrayType.token;
+	case Ast_StructType:       return node->StructType.token;
+	case Ast_UnionType:        return node->UnionType.token;
+	case Ast_EnumType:         return node->EnumType.token;
+	case Ast_BitSetType:       return node->BitSetType.token;
+	case Ast_MapType:          return node->MapType.token;
+	}
+
+	return empty_token;
+}
+
+TokenPos token_pos_end(Token const &token) {
+	TokenPos pos = token.pos;
+	pos.offset += cast(i32)token.string.len;
+	for (isize i = 0; i < token.string.len; i++) {
+		// TODO(bill): This assumes ASCII
+		char c = token.string[i];
+		if (c == '\n') {
+			pos.line += 1;
+			pos.column = 1;
+		} else {
+			pos.column += 1;
+		}
+	}
+	return pos;
+}
+
+Token ast_end_token(Ast *node) {
+	GB_ASSERT(node != nullptr);
+
+	switch (node->kind) {
+	case Ast_Ident:          return node->Ident.token;
+	case Ast_Implicit:       return node->Implicit;
+	case Ast_Undef:          return node->Undef;
+	case Ast_BasicLit:       return node->BasicLit.token;
+	case Ast_BasicDirective: return node->BasicDirective.token;
+	case Ast_ProcGroup:      return node->ProcGroup.close;
+	case Ast_ProcLit:
+		if (node->ProcLit.body) {
+			return ast_end_token(node->ProcLit.body);
+		}
+		return ast_end_token(node->ProcLit.type);
+	case Ast_CompoundLit:
+		return node->CompoundLit.close;
+
+	case Ast_BadExpr:       return node->BadExpr.end;
+	case Ast_TagExpr:       return ast_end_token(node->TagExpr.expr);
+	case Ast_UnaryExpr:     return ast_end_token(node->UnaryExpr.expr);
+	case Ast_BinaryExpr:    return ast_end_token(node->BinaryExpr.right);
+	case Ast_ParenExpr:     return node->ParenExpr.close;
+	case Ast_CallExpr:      return node->CallExpr.close;
+	case Ast_SelectorExpr:
+		return ast_end_token(node->SelectorExpr.selector);
+	case Ast_SelectorCallExpr:
+		return ast_end_token(node->SelectorCallExpr.call);
+	case Ast_ImplicitSelectorExpr:
+		return ast_end_token(node->SelectorExpr.selector);
+	case Ast_IndexExpr:          return node->IndexExpr.close;
+	case Ast_SliceExpr:          return node->SliceExpr.close;
+	case Ast_Ellipsis:
+		if (node->Ellipsis.expr) {
+			return ast_end_token(node->Ellipsis.expr);
+		}
+		return node->Ellipsis.token;
+	case Ast_FieldValue:         return ast_end_token(node->FieldValue.value);
+	case Ast_DerefExpr:          return node->DerefExpr.op;
+	case Ast_TernaryIfExpr:      return ast_end_token(node->TernaryIfExpr.y);
+	case Ast_TernaryWhenExpr:    return ast_end_token(node->TernaryWhenExpr.y);
+	case Ast_TypeAssertion:      return ast_end_token(node->TypeAssertion.type);
+	case Ast_TypeCast:           return ast_end_token(node->TypeCast.expr);
+	case Ast_AutoCast:           return ast_end_token(node->AutoCast.expr);
+	case Ast_InlineAsmExpr:      return node->InlineAsmExpr.close;
+
+	case Ast_BadStmt:            return node->BadStmt.end;
+	case Ast_EmptyStmt:          return node->EmptyStmt.token;
+	case Ast_ExprStmt:           return ast_end_token(node->ExprStmt.expr);
+	case Ast_TagStmt:            return ast_end_token(node->TagStmt.stmt);
+	case Ast_AssignStmt:
+		if (node->AssignStmt.rhs.count > 0) {
+			return ast_end_token(node->AssignStmt.rhs[node->AssignStmt.rhs.count-1]);
+		}
+		return node->AssignStmt.op;
+	case Ast_BlockStmt:          return node->BlockStmt.close;
+	case Ast_IfStmt:
+		if (node->IfStmt.else_stmt) {
+			return ast_end_token(node->IfStmt.else_stmt);
+		}
+		return ast_end_token(node->IfStmt.body);
+	case Ast_WhenStmt:
+		if (node->WhenStmt.else_stmt) {
+			return ast_end_token(node->WhenStmt.else_stmt);
+		}
+		return ast_end_token(node->WhenStmt.body);
+	case Ast_ReturnStmt:
+		if (node->ReturnStmt.results.count > 0) {
+			return ast_end_token(node->ReturnStmt.results[node->ReturnStmt.results.count-1]);
+		}
+		return node->ReturnStmt.token;
+	case Ast_ForStmt:            return ast_end_token(node->ForStmt.body);
+	case Ast_RangeStmt:          return ast_end_token(node->RangeStmt.body);
+	case Ast_UnrollRangeStmt:    return ast_end_token(node->UnrollRangeStmt.body);
+	case Ast_CaseClause:
+		if (node->CaseClause.stmts.count) {
+			return ast_end_token(node->CaseClause.stmts[node->CaseClause.stmts.count-1]);
+		} else if (node->CaseClause.list.count) {
+			return ast_end_token(node->CaseClause.list[node->CaseClause.list.count-1]);
+		}
+		return node->CaseClause.token;
+	case Ast_SwitchStmt:         return ast_end_token(node->SwitchStmt.body);
+	case Ast_TypeSwitchStmt:     return ast_end_token(node->TypeSwitchStmt.body);
+	case Ast_DeferStmt:          return ast_end_token(node->DeferStmt.stmt);
+	case Ast_BranchStmt:
+		if (node->BranchStmt.label) {
+			return ast_end_token(node->BranchStmt.label);
+		}
+		return node->BranchStmt.token;
+	case Ast_UsingStmt:
+		if (node->UsingStmt.list.count > 0) {
+			return ast_end_token(node->UsingStmt.list[node->UsingStmt.list.count-1]);
+		}
+		return node->UsingStmt.token;
+
+	case Ast_BadDecl:            return node->BadDecl.end;
+	case Ast_Label:
+		if (node->Label.name) {
+			return ast_end_token(node->Label.name);
+		}
+		return node->Label.token;
+
+	case Ast_ValueDecl:
+		if (node->ValueDecl.values.count > 0) {
+			return ast_end_token(node->ValueDecl.values[node->ValueDecl.values.count-1]);
+		}
+		if (node->ValueDecl.type) {
+			return ast_end_token(node->ValueDecl.type);
+		}
+		if (node->ValueDecl.names.count > 0) {
+			return ast_end_token(node->ValueDecl.names[node->ValueDecl.names.count-1]);
+		}
+		return {};
+
+	case Ast_PackageDecl:        return node->PackageDecl.name;
+	case Ast_ImportDecl:         return node->ImportDecl.relpath;
+	case Ast_ForeignImportDecl:
+		if (node->ForeignImportDecl.filepaths.count > 0) {
+			return node->ForeignImportDecl.filepaths[node->ForeignImportDecl.filepaths.count-1];
+		}
+		if (node->ForeignImportDecl.library_name.kind != Token_Invalid) {
+			return node->ForeignImportDecl.library_name;
+		}
+		return node->ForeignImportDecl.token;
+
+	case Ast_ForeignBlockDecl:
+		return ast_end_token(node->ForeignBlockDecl.body);
+
+	case Ast_Attribute:
+		if (node->Attribute.close.kind != Token_Invalid) {
+			return node->Attribute.close;
+		}
+		return ast_end_token(node->Attribute.elems[node->Attribute.elems.count-1]);
+
+	case Ast_Field:
+		if (node->Field.tag.kind != Token_Invalid) {
+			return node->Field.tag;
+		}
+		if (node->Field.default_value) {
+			return ast_end_token(node->Field.default_value);
+		}
+		if (node->Field.type) {
+			return ast_end_token(node->Field.type);
+		}
+		return ast_end_token(node->Field.names[node->Field.names.count-1]);
+	case Ast_FieldList:
+		if (node->FieldList.list.count > 0) {
+			return ast_end_token(node->FieldList.list[node->FieldList.list.count-1]);
+		}
+		return node->FieldList.token;
+
+	case Ast_TypeidType:
+		if (node->TypeidType.specialization) {
+			return ast_end_token(node->TypeidType.specialization);
+		}
+		return node->TypeidType.token;
+	case Ast_HelperType:       return ast_end_token(node->HelperType.type);
+	case Ast_DistinctType:     return ast_end_token(node->DistinctType.type);
+	case Ast_PolyType:
+		if (node->PolyType.specialization) {
+			return ast_end_token(node->PolyType.specialization);
+		}
+		return ast_end_token(node->PolyType.type);
+	case Ast_ProcType:
+		if (node->ProcType.results) {
+			return ast_end_token(node->ProcType.results);
+		}
+		if (node->ProcType.params) {
+			return ast_end_token(node->ProcType.params);
+		}
+		return node->ProcType.token;
+	case Ast_RelativeType:
+		return ast_end_token(node->RelativeType.type);
+	case Ast_PointerType:      return ast_end_token(node->PointerType.type);
+	case Ast_ArrayType:        return ast_end_token(node->ArrayType.elem);
+	case Ast_DynamicArrayType: return ast_end_token(node->DynamicArrayType.elem);
+	case Ast_StructType:
+		if (node->StructType.fields.count > 0) {
+			return ast_end_token(node->StructType.fields[node->StructType.fields.count-1]);
+		}
+		return node->StructType.token;
+	case Ast_UnionType:
+		if (node->UnionType.variants.count > 0) {
+			return ast_end_token(node->UnionType.variants[node->UnionType.variants.count-1]);
+		}
+		return node->UnionType.token;
+	case Ast_EnumType:
+		if (node->EnumType.fields.count > 0) {
+			return ast_end_token(node->EnumType.fields[node->EnumType.fields.count-1]);
+		}
+		if (node->EnumType.base_type) {
+			return ast_end_token(node->EnumType.base_type);
+		}
+		return node->EnumType.token;
+	case Ast_BitSetType:
+		if (node->BitSetType.underlying) {
+			return ast_end_token(node->BitSetType.underlying);
+		}
+		return ast_end_token(node->BitSetType.elem);
+	case Ast_MapType:          return ast_end_token(node->MapType.value);
+	}
+
+	return empty_token;
+}
+
+TokenPos ast_end_pos(Ast *node) {
+	return token_pos_end(ast_end_token(node));
+}
diff --git a/src/thread_pool.cpp b/src/thread_pool.cpp
index 2467ba609..73118321b 100644
--- a/src/thread_pool.cpp
+++ b/src/thread_pool.cpp
@@ -35,8 +35,6 @@ void thread_pool_destroy(ThreadPool *pool);
 void thread_pool_start(ThreadPool *pool);
 void thread_pool_join(ThreadPool *pool);
 void thread_pool_add_task(ThreadPool *pool, WorkerTaskProc *proc, void *data);
-void thread_pool_kick(ThreadPool *pool);
-void thread_pool_kick_and_wait(ThreadPool *pool);
 GB_THREAD_PROC(worker_thread_internal);
 
 void thread_pool_init(ThreadPool *pool, gbAllocator const &a, isize thread_count, char const *worker_prefix) {
@@ -181,4 +179,3 @@ GB_THREAD_PROC(worker_thread_internal) {
 
 	return 0;
 }
-
diff --git a/src/tokenizer.cpp b/src/tokenizer.cpp
index 081ef6443..826fccc04 100644
--- a/src/tokenizer.cpp
+++ b/src/tokenizer.cpp
@@ -51,8 +51,10 @@ TOKEN_KIND(Token__AssignOpBegin, ""), \
 	TOKEN_KIND(Token_CmpAndEq, "&&="), \
 	TOKEN_KIND(Token_CmpOrEq,  "||="), \
 TOKEN_KIND(Token__AssignOpEnd, ""), \
-	TOKEN_KIND(Token_ArrowRight,       "->"), \
-	TOKEN_KIND(Token_Undef,            "---"), \
+	TOKEN_KIND(Token_Increment, "++"), \
+	TOKEN_KIND(Token_Decrement, "--"), \
+	TOKEN_KIND(Token_ArrowRight,"->"), \
+	TOKEN_KIND(Token_Undef,     "---"), \
 \
 TOKEN_KIND(Token__ComparisonBegin, ""), \
 	TOKEN_KIND(Token_CmpEq, "=="), \
@@ -74,6 +76,7 @@ TOKEN_KIND(Token__ComparisonEnd, ""), \
 	TOKEN_KIND(Token_Period,        "."),   \
 	TOKEN_KIND(Token_Comma,         ","),   \
 	TOKEN_KIND(Token_Ellipsis,      ".."),  \
+	TOKEN_KIND(Token_RangeFull,     "..="), \
 	TOKEN_KIND(Token_RangeHalf,     "..<"), \
 	TOKEN_KIND(Token_BackSlash,     "\\"),  \
 TOKEN_KIND(Token__OperatorEnd, ""), \
@@ -185,9 +188,11 @@ void init_keyword_hash_table(void) {
 	GB_ASSERT(max_keyword_size < 16);
 }
 
-gb_global Array<String> global_file_path_strings; // index is file id
+gb_global Array<String>           global_file_path_strings; // index is file id
+gb_global Array<struct AstFile *> global_files; // index is file id
 
-String get_file_path_string(i32 index);
+String   get_file_path_string(i32 index);
+struct AstFile *get_ast_file_from_id(i32 index);
 
 struct TokenPos {
 	i32 file_id;
@@ -281,6 +286,7 @@ void init_global_error_collector(void) {
 	array_init(&global_error_collector.errors, heap_allocator());
 	array_init(&global_error_collector.error_buffer, heap_allocator());
 	array_init(&global_file_path_strings, heap_allocator(), 4096);
+	array_init(&global_files, heap_allocator(), 4096);
 }
 
 
@@ -302,6 +308,24 @@ bool set_file_path_string(i32 index, String const &path) {
 	return ok;
 }
 
+bool set_ast_file_from_id(i32 index, AstFile *file) {
+	bool ok = false;
+	GB_ASSERT(index >= 0);
+	gb_mutex_lock(&global_error_collector.string_mutex);
+
+	if (index >= global_files.count) {
+		array_resize(&global_files, index);
+	}
+	AstFile *prev = global_files[index];
+	if (prev == nullptr) {
+		global_files[index] = file;
+		ok = true;
+	}
+
+	gb_mutex_unlock(&global_error_collector.string_mutex);
+	return ok;
+}
+
 String get_file_path_string(i32 index) {
 	GB_ASSERT(index >= 0);
 	gb_mutex_lock(&global_error_collector.string_mutex);
@@ -315,6 +339,20 @@ String get_file_path_string(i32 index) {
 	return path;
 }
 
+AstFile *get_ast_file_from_id(i32 index) {
+	GB_ASSERT(index >= 0);
+	gb_mutex_lock(&global_error_collector.string_mutex);
+
+	AstFile *file = nullptr;
+	if (index < global_files.count) {
+		file = global_files[index];
+	}
+
+	gb_mutex_unlock(&global_error_collector.string_mutex);
+	return file;
+}
+
+
 void begin_error_block(void) {
 	gb_mutex_lock(&global_error_collector.mutex);
 	global_error_collector.in_block = true;
@@ -374,6 +412,8 @@ ErrorOutProc *error_out_va = default_error_out_va;
 // NOTE: defined in build_settings.cpp
 bool global_warnings_as_errors(void);
 bool global_ignore_warnings(void);
+bool show_error_line(void);
+gbString get_file_line_as_string(TokenPos const &pos, i32 *offset);
 
 void error_out(char const *fmt, ...) {
 	va_list va;
@@ -383,17 +423,85 @@ void error_out(char const *fmt, ...) {
 }
 
 
-void error_va(Token token, char const *fmt, va_list va) {
+bool show_error_on_line(TokenPos const &pos, TokenPos end) {
+	if (!show_error_line()) {
+		return false;
+	}
+
+	i32 offset = 0;
+	gbString the_line = get_file_line_as_string(pos, &offset);
+	defer (gb_string_free(the_line));
+
+	if (the_line != nullptr) {
+		String line = make_string(cast(u8 const *)the_line, gb_string_length(the_line));
+
+		// TODO(bill): This assumes ASCII
+
+		enum {
+			MAX_LINE_LENGTH  = 76,
+			MAX_TAB_WIDTH    = 8,
+			ELLIPSIS_PADDING = 8
+		};
+
+		error_out("\n\t");
+		if (line.len+MAX_TAB_WIDTH+ELLIPSIS_PADDING > MAX_LINE_LENGTH) {
+			i32 const half_width = MAX_LINE_LENGTH/2;
+			i32 left  = cast(i32)(offset);
+			i32 right = cast(i32)(line.len - offset);
+			left  = gb_min(left, half_width);
+			right = gb_min(right, half_width);
+
+			line.text += offset-left;
+			line.len  -= offset+right-left;
+
+			line = string_trim_whitespace(line);
+
+			offset = left + ELLIPSIS_PADDING/2;
+
+			error_out("... %.*s ...", LIT(line));
+		} else {
+			error_out("%.*s", LIT(line));
+		}
+		error_out("\n\t");
+
+		for (i32 i = 0; i < offset; i++) {
+			error_out(" ");
+		}
+		error_out("^");
+		if (end.file_id == pos.file_id) {
+			if (end.line > pos.line) {
+				for (i32 i = offset; i < line.len; i++) {
+					error_out("~");
+				}
+			} else if (end.line == pos.line && end.column > pos.column) {
+				i32 length = gb_min(end.offset - pos.offset, cast(i32)(line.len-offset));
+				for (i32 i = 1; i < length-1; i++) {
+					error_out("~");
+				}
+				if (length > 1) {
+					error_out("^");
+				}
+			}
+		}
+
+		error_out("\n\n");
+		return true;
+	}
+	return false;
+}
+
+void error_va(TokenPos const &pos, TokenPos end, char const *fmt, va_list va) {
 	gb_mutex_lock(&global_error_collector.mutex);
 	global_error_collector.count++;
 	// NOTE(bill): Duplicate error, skip it
-	if (token.pos.line == 0) {
+	if (pos.line == 0) {
 		error_out("Error: %s\n", gb_bprintf_va(fmt, va));
-	} else if (global_error_collector.prev != token.pos) {
-		global_error_collector.prev = token.pos;
+	} else if (global_error_collector.prev != pos) {
+		global_error_collector.prev = pos;
 		error_out("%s %s\n",
-		          token_pos_to_string(token.pos),
+		          token_pos_to_string(pos),
 		          gb_bprintf_va(fmt, va));
+		show_error_on_line(pos, end);
 	}
 	gb_mutex_unlock(&global_error_collector.mutex);
 	if (global_error_collector.count > MAX_ERROR_COLLECTOR_COUNT) {
@@ -401,22 +509,23 @@ void error_va(Token token, char const *fmt, va_list va) {
 	}
 }
 
-void warning_va(Token token, char const *fmt, va_list va) {
+void warning_va(TokenPos const &pos, TokenPos end, char const *fmt, va_list va) {
 	if (global_warnings_as_errors()) {
-		error_va(token, fmt, va);
+		error_va(pos, end, fmt, va);
 		return;
 	}
 	gb_mutex_lock(&global_error_collector.mutex);
 	global_error_collector.warning_count++;
 	if (!global_ignore_warnings()) {
 		// NOTE(bill): Duplicate error, skip it
-		if (token.pos.line == 0) {
+		if (pos.line == 0) {
 			error_out("Warning: %s\n", gb_bprintf_va(fmt, va));
-		} else if (global_error_collector.prev != token.pos) {
-			global_error_collector.prev = token.pos;
+		} else if (global_error_collector.prev != pos) {
+			global_error_collector.prev = pos;
 			error_out("%s Warning: %s\n",
-			          token_pos_to_string(token.pos),
+			          token_pos_to_string(pos),
 			          gb_bprintf_va(fmt, va));
+			show_error_on_line(pos, end);
 		}
 	}
 	gb_mutex_unlock(&global_error_collector.mutex);
@@ -429,16 +538,16 @@ void error_line_va(char const *fmt, va_list va) {
 	gb_mutex_unlock(&global_error_collector.mutex);
 }
 
-void error_no_newline_va(Token token, char const *fmt, va_list va) {
+void error_no_newline_va(TokenPos const &pos, char const *fmt, va_list va) {
 	gb_mutex_lock(&global_error_collector.mutex);
 	global_error_collector.count++;
 	// NOTE(bill): Duplicate error, skip it
-	if (token.pos.line == 0) {
+	if (pos.line == 0) {
 		error_out("Error: %s", gb_bprintf_va(fmt, va));
-	} else if (global_error_collector.prev != token.pos) {
-		global_error_collector.prev = token.pos;
+	} else if (global_error_collector.prev != pos) {
+		global_error_collector.prev = pos;
 		error_out("%s %s",
-		          token_pos_to_string(token.pos),
+		          token_pos_to_string(pos),
 		          gb_bprintf_va(fmt, va));
 	}
 	gb_mutex_unlock(&global_error_collector.mutex);
@@ -448,16 +557,17 @@ void error_no_newline_va(Token token, char const *fmt, va_list va) {
 }
 
 
-void syntax_error_va(Token token, char const *fmt, va_list va) {
+void syntax_error_va(TokenPos const &pos, TokenPos end, char const *fmt, va_list va) {
 	gb_mutex_lock(&global_error_collector.mutex);
 	global_error_collector.count++;
 	// NOTE(bill): Duplicate error, skip it
-	if (global_error_collector.prev != token.pos) {
-		global_error_collector.prev = token.pos;
+	if (global_error_collector.prev != pos) {
+		global_error_collector.prev = pos;
 		error_out("%s Syntax Error: %s\n",
-		          token_pos_to_string(token.pos),
+		          token_pos_to_string(pos),
 		          gb_bprintf_va(fmt, va));
-	} else if (token.pos.line == 0) {
+		show_error_on_line(pos, end);
+	} else if (pos.line == 0) {
 		error_out("Syntax Error: %s\n", gb_bprintf_va(fmt, va));
 	}
 
@@ -467,21 +577,22 @@ void syntax_error_va(Token token, char const *fmt, va_list va) {
 	}
 }
 
-void syntax_warning_va(Token token, char const *fmt, va_list va) {
+void syntax_warning_va(TokenPos const &pos, TokenPos end, char const *fmt, va_list va) {
 	if (global_warnings_as_errors()) {
-		syntax_error_va(token, fmt, va);
+		syntax_error_va(pos, end, fmt, va);
 		return;
 	}
 	gb_mutex_lock(&global_error_collector.mutex);
 	global_error_collector.warning_count++;
 	if (!global_ignore_warnings()) {
 		// NOTE(bill): Duplicate error, skip it
-		if (global_error_collector.prev != token.pos) {
-			global_error_collector.prev = token.pos;
+		if (global_error_collector.prev != pos) {
+			global_error_collector.prev = pos;
 			error_out("%s Syntax Warning: %s\n",
-			          token_pos_to_string(token.pos),
+			          token_pos_to_string(pos),
 			          gb_bprintf_va(fmt, va));
-		} else if (token.pos.line == 0) {
+			show_error_on_line(pos, end);
+		} else if (pos.line == 0) {
 			error_out("Warning: %s\n", gb_bprintf_va(fmt, va));
 		}
 	}
@@ -490,17 +601,17 @@ void syntax_warning_va(Token token, char const *fmt, va_list va) {
 
 
 
-void warning(Token token, char const *fmt, ...) {
+void warning(Token const &token, char const *fmt, ...) {
 	va_list va;
 	va_start(va, fmt);
-	warning_va(token, fmt, va);
+	warning_va(token.pos, {}, fmt, va);
 	va_end(va);
 }
 
-void error(Token token, char const *fmt, ...) {
+void error(Token const &token, char const *fmt, ...) {
 	va_list va;
 	va_start(va, fmt);
-	error_va(token, fmt, va);
+	error_va(token.pos, {}, fmt, va);
 	va_end(va);
 }
 
@@ -509,7 +620,7 @@ void error(TokenPos pos, char const *fmt, ...) {
 	va_start(va, fmt);
 	Token token = {};
 	token.pos = pos;
-	error_va(token, fmt, va);
+	error_va(pos, {}, fmt, va);
 	va_end(va);
 }
 
@@ -521,26 +632,24 @@ void error_line(char const *fmt, ...) {
 }
 
 
-void syntax_error(Token token, char const *fmt, ...) {
+void syntax_error(Token const &token, char const *fmt, ...) {
 	va_list va;
 	va_start(va, fmt);
-	syntax_error_va(token, fmt, va);
+	syntax_error_va(token.pos, {}, fmt, va);
 	va_end(va);
 }
 
 void syntax_error(TokenPos pos, char const *fmt, ...) {
 	va_list va;
 	va_start(va, fmt);
-	Token token = {};
-	token.pos = pos;
-	syntax_error_va(token, fmt, va);
+	syntax_error_va(pos, {}, fmt, va);
 	va_end(va);
 }
 
-void syntax_warning(Token token, char const *fmt, ...) {
+void syntax_warning(Token const &token, char const *fmt, ...) {
 	va_list va;
 	va_start(va, fmt);
-	syntax_warning_va(token, fmt, va);
+	syntax_warning_va(token.pos, {}, fmt, va);
 	va_end(va);
 }
 
@@ -652,13 +761,14 @@ void tokenizer_err(Tokenizer *t, char const *msg, ...) {
 	if (column < 1) {
 		column = 1;
 	}
-	Token token = {};
-	token.pos.file_id = t->curr_file_id;
-	token.pos.line = t->line_count;
-	token.pos.column = cast(i32)column;
+	TokenPos pos = {};
+	pos.file_id = t->curr_file_id;
+	pos.line = t->line_count;
+	pos.column = cast(i32)column;
+	pos.offset = cast(i32)(t->read_curr - t->start);
 
 	va_start(va, msg);
-	syntax_error_va(token, msg, va);
+	syntax_error_va(pos, {}, msg, va);
 	va_end(va);
 
 	t->error_count++;
@@ -670,11 +780,9 @@ void tokenizer_err(Tokenizer *t, TokenPos const &pos, char const *msg, ...) {
 	if (column < 1) {
 		column = 1;
 	}
-	Token token = {};
-	token.pos = pos;
 
 	va_start(va, msg);
-	syntax_error_va(token, msg, va);
+	syntax_error_va(pos, {}, msg, va);
 	va_end(va);
 
 	t->error_count++;
@@ -1202,6 +1310,9 @@ void tokenizer_get_token(Tokenizer *t, Token *token, int repeat=0) {
 				if (t->curr_rune == '<') {
 					advance_to_next_rune(t);
 					token->kind = Token_RangeHalf;
+				} else if (t->curr_rune == '=') {
+					advance_to_next_rune(t);
+					token->kind = Token_RangeFull;
 				}
 			} else if ('0' <= t->curr_rune && t->curr_rune <= '9') {
 				scan_number_to_token(t, token, true);
@@ -1287,6 +1398,10 @@ void tokenizer_get_token(Tokenizer *t, Token *token, int repeat=0) {
 			if (t->curr_rune == '=') {
 				advance_to_next_rune(t);
 				token->kind = Token_AddEq;
+			} else if (t->curr_rune == '+') {
+				advance_to_next_rune(t);
+				token->kind = Token_Increment;
+				insert_semicolon = true;
 			}
 			break;
 		case '-':
@@ -1298,6 +1413,10 @@ void tokenizer_get_token(Tokenizer *t, Token *token, int repeat=0) {
 				advance_to_next_rune(t);
 				advance_to_next_rune(t);
 				token->kind = Token_Undef;
+			} else if (t->curr_rune == '-') {
+				advance_to_next_rune(t);
+				token->kind = Token_Decrement;
+				insert_semicolon = true;
 			} else if (t->curr_rune == '>') {
 				advance_to_next_rune(t);
 				token->kind = Token_ArrowRight;
diff --git a/src/types.cpp b/src/types.cpp
index 56081acc8..8a78e08d1 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -128,21 +128,6 @@ enum StructSoaKind {
 	StructSoa_Dynamic = 3,
 };
 
-enum TypeAtomOpKind {
-	TypeAtomOp_Invalid,
-
-	TypeAtomOp_index_get,
-	TypeAtomOp_index_set,
-	TypeAtomOp_slice,
-	TypeAtomOp_index_get_ptr,
-
-	TypeAtomOp_COUNT,
-};
-
-struct TypeAtomOpTable {
-	Entity *op[TypeAtomOp_COUNT];
-};
-
 struct TypeStruct {
 	Array<Entity *> fields;
 	Array<String>   tags;
@@ -156,8 +141,6 @@ struct TypeStruct {
 	i64      custom_align;
 	Entity * names;
 
-	TypeAtomOpTable *atom_op_table;
-
 	Type *        soa_elem;
 	i64           soa_count;
 	StructSoaKind soa_kind;
@@ -180,8 +163,6 @@ struct TypeUnion {
 	Type *        polymorphic_params; // Type_Tuple
 	Type *        polymorphic_parent;
 
-	TypeAtomOpTable *atom_op_table;
-
 	bool          no_nil;
 	bool          maybe;
 	bool          is_polymorphic;
@@ -1915,6 +1896,18 @@ bool is_type_comparable(Type *t) {
 			}
 		}
 		return true;
+
+	case Type_Union:
+		if (type_size_of(t) == 0) {
+			return false;
+		}
+		for_array(i, t->Union.variants) {
+			Type *v = t->Union.variants[i];
+			if (!is_type_comparable(v)) {
+				return false;
+			}
+		}
+		return true;
 	}
 	return false;
 }
@@ -1959,7 +1952,8 @@ bool is_type_simple_compare(Type *t) {
 				return false;
 			}
 		}
-		return true;
+		// make it dumb on purpose
+		return t->Union.variants.count == 1;
 
 	case Type_SimdVector:
 		return is_type_simple_compare(t->SimdVector.elem);
@@ -2766,7 +2760,36 @@ void type_path_pop(TypePath *tp) {
 
 i64 type_size_of_internal (Type *t, TypePath *path);
 i64 type_align_of_internal(Type *t, TypePath *path);
+i64 type_size_of(Type *t);
+i64 type_align_of(Type *t);
 
+i64 type_size_of_struct_pretend_is_packed(Type *ot) {
+	if (ot == nullptr) {
+		return 0;
+	}
+	Type *t = core_type(ot);
+	if (t->kind != Type_Struct) {
+		return type_size_of(ot);
+	}
+
+	if (t->Struct.is_packed) {
+		return type_size_of(ot);
+	}
+
+	i64 count = 0, size = 0, align = 1;
+
+	auto const &fields = t->Struct.fields;
+	count = fields.count;
+	if (count == 0) {
+		return 0;
+	}
+
+	for_array(i, fields) {
+		size += type_size_of(fields[i]->type);
+	}
+
+	return align_formula(size, align);
+}
 
 
 i64 type_size_of(Type *t) {
@@ -3618,6 +3641,9 @@ gbString write_type_to_string(gbString str, Type *type) {
 		case ProcCC_None:
 			str = gb_string_appendc(str, " \"none\" ");
 			break;
+		case ProcCC_Naked:
+			str = gb_string_appendc(str, " \"naked\" ");
+			break;
 		// case ProcCC_VectorCall:
 		// 	str = gb_string_appendc(str, " \"vectorcall\" ");
 		// 	break;