Restart LLVM IR SSA generation

This is the third go and I'm going for it!

4 files changed, 1465 insertions, 0 deletions

diff --git a/src/codegen/codegen.cpp b/src/codegen/codegen.cpp
new file mode 100644
index 000000000..a28d0d170
--- /dev/null
+++ b/src/codegen/codegen.cpp
@@ -0,0 +1,318 @@
+#include "ssa.cpp"
+#include "print.cpp"
+
+struct ssaGen {
+	ssaModule module;
+	gbFile output_file;
+};
+
+b32 ssa_gen_init(ssaGen *s, Checker *c) {
+	if (c->error_collector.count != 0)
+		return false;
+
+	gb_for_array(i, c->parser->files) {
+		AstFile *f = &c->parser->files[i];
+		if (f->error_collector.count != 0)
+			return false;
+		if (f->tokenizer.error_count != 0)
+			return false;
+	}
+
+	ssa_module_init(&s->module, c);
+
+	gbFileError err = gb_file_create(&s->output_file, "../examples/test.ll");
+	if (err != gbFileError_None)
+		return false;
+
+	return true;
+}
+
+void ssa_gen_destroy(ssaGen *s) {
+	ssa_module_destroy(&s->module);
+	gb_file_close(&s->output_file);
+}
+
+void ssa_gen_code(ssaGen *s) {
+	ssaModule *m = &s->module;
+	CheckerInfo *info = m->info;
+	gbAllocator a = m->allocator;
+	gb_for_array(i, info->entities.entries) {
+		auto *entry = &info->entities.entries[i];
+		Entity *e = cast(Entity *)cast(uintptr)entry->key;
+		DeclarationInfo *decl = entry->value;
+
+		String name = e->token.string;
+
+		switch (e->kind) {
+		case Entity_TypeName: {
+			ssaValue *t = ssa_make_value_type_name(a, e);
+			map_set(&m->members, hash_string(name), t);
+		} break;
+
+		case Entity_Variable: {
+			ssaValue *g = ssa_make_value_global(a, e, NULL);
+			map_set(&m->values, hash_pointer(e), g);
+			map_set(&m->members, hash_string(name), g);
+		} break;
+
+		case Entity_Procedure: {
+			ssaValue *p = ssa_make_value_procedure(a, e, decl, m);
+			map_set(&m->values, hash_pointer(e), p);
+			map_set(&m->members, hash_string(name), p);
+		} break;
+		}
+	}
+
+	gb_for_array(i, m->members.entries) {
+		auto *entry = &m->members.entries[i];
+		ssaValue *v = entry->value;
+		if (v->kind == ssaValue_Procedure)
+			ssa_build_procedure(v);
+	}
+
+	ssa_print_llvm_ir(&s->output_file, &s->module);
+}
+
+
+
+
+
+#if 0
+#include "type.cpp"
+#include "ir.cpp"
+
+struct Codegen {
+	Checker *checker;
+	gbFile file;
+	gbAllocator allocator;
+
+	irModule module;
+
+	ErrorCollector error_collector;
+};
+
+b32 init_codegen(Codegen *c, Checker *checker) {
+	c->checker = checker;
+
+	if (c->error_collector.count != 0)
+		return false;
+	for (isize i = 0; i < gb_array_count(checker->parser->files); i++) {
+		AstFile *f = &checker->parser->files[i];
+		if (f->error_collector.count != 0)
+			return false;
+		if (f->tokenizer.error_count != 0)
+			return false;
+	}
+
+	c->allocator = gb_heap_allocator();
+
+	ir_module_init(&c->module, c->checker);
+
+	return true;
+}
+
+void destroy_codegen(Codegen *c) {
+	ir_module_destroy(&c->module);
+}
+
+b32 is_blank_identifier(AstNode *identifier) {
+	if (identifier->kind == AstNode_Identifier) {
+		return are_strings_equal(identifier->identifier.token.string, make_string("_"));
+	}
+	return false;
+}
+
+
+irValue *ir_add_basic_block(gbAllocator a, irValue *p, String label) {
+	irValue *b = ir_make_value_basic_block(a, gb_array_count(p->procedure.blocks), label, p);
+	gb_array_append(p->procedure.blocks, b);
+	return b;
+}
+
+irValue *ir_emit_from_block(irValue *b, irInstruction *i) {
+	GB_ASSERT(b->kind == irValue_BasicBlock);
+	i->block = b;
+	gb_array_append(b->basic_block.instructions, i);
+	return ir_make_value_instruction(gb_heap_allocator(), i);
+}
+
+
+irValue *ir_emit(irValue *p, irInstruction *i) {
+	GB_ASSERT(p->kind == irValue_Procedure);
+	return ir_emit_from_block(p->procedure.curr_block, i);
+}
+
+
+irInstruction *ir_add_local(irValue *p, Type *type, TokenPos pos) {
+	irInstruction *i = ir_alloc_instruction(gb_heap_allocator(), irInstruction_Alloca);
+	i->reg.type = type;
+	i->reg.pos = pos;
+	gb_array_append(p->procedure.locals, ir_emit(p, i));
+	return i;
+}
+
+irInstruction *ir_add_named_local(irValue *p, Entity *e) {
+	irInstruction *i = ir_add_local(p, e->type, e->token.pos);
+	i->alloca.label = e->token.string;
+	// map_set(&p->procedure.variables, hash_pointer(e), );
+	return i;
+}
+
+irInstruction *ir_add_local_for_identifier(irValue *p, AstNode *i) {
+	GB_ASSERT(p->kind == irValue_Procedure);
+	GB_ASSERT(i->kind == AstNode_Identifier);
+	auto *found = map_get(&p->procedure.module->checker->definitions, hash_pointer(i));
+	return ir_add_named_local(p, *found);
+}
+
+
+void ir_build_variable_declaration(irValue *p, AstNode *d) {
+	GB_ASSERT(p->kind == irValue_Procedure);
+	auto *vd = &d->variable_declaration;
+
+	if (vd->name_count == vd->value_count) {
+		AstNode *name = vd->name_list;
+		AstNode *value = vd->value_list;
+		for (;
+		     name != NULL && value != NULL;
+		     name = name->next, value = value->next) {
+			if (!is_blank_identifier(name)) {
+				ir_add_local_for_identifier(p, name);
+			}
+			// auto lvalue = build_address(p, name, false);
+			// build_assignment(p, lvalue, value, true, NULL);
+		}
+	} else if (vd->value_count == 0) {
+		AstNode *name = vd->name_list;
+		for (;
+		     name != NULL;
+		     name = name->next) {
+			if (!is_blank_identifier(name)) {
+
+			}
+
+			// build_assignment(p, )
+		}
+	} else {
+		// TODO(bill): Tuple
+	}
+
+}
+
+
+void ir_build_expression(irValue *p, AstNode *e) {
+	GB_ASSERT(p->kind == irValue_Procedure);
+
+}
+
+
+void ir_build_statement(irValue *p, AstNode *s);
+
+void ir_build_statement_list(irValue *p, AstNode *list) {
+	GB_ASSERT(p->kind == irValue_Procedure);
+	for (AstNode *item = list; item != NULL; item = item->next) {
+		ir_build_statement(p, item);
+	}
+}
+
+void ir_build_statement(irValue *p, AstNode *s) {
+	GB_ASSERT(p->kind == irValue_Procedure);
+
+	switch (s->kind) {
+	case AstNode_EmptyStatement:
+		break;
+
+	case AstNode_VariableDeclaration: {
+		auto *vd = &s->variable_declaration;
+		if (vd->kind == Declaration_Mutable) {
+			ir_build_variable_declaration(p, s);
+		}
+	} break;
+
+
+	case AstNode_ExpressionStatement:
+		ir_build_expression(p, s->expression_statement.expression);
+		break;
+
+	case AstNode_BlockStatement:
+		ir_build_statement_list(p, s->block_statement.list);
+		break;
+	}
+
+}
+
+
+
+
+
+void ir_begin_procedure_body(irValue *p) {
+	gbAllocator a = gb_heap_allocator();
+	p->procedure.curr_block = ir_add_basic_block(a, p, make_string("entry"));
+	map_init(&p->procedure.variables, a);
+}
+
+void ir_end_procedure_body(irValue *p) {
+	p->procedure.curr_block = NULL;
+	map_destroy(&p->procedure.variables);
+}
+
+
+void ir_build_procedure(irModule *m, irValue *p) {
+	if (p->procedure.blocks != NULL)
+		return;
+	AstNode *proc_type = NULL;
+	AstNode *body = NULL;
+	switch (p->procedure.node->kind) {
+	case AstNode_ProcedureDeclaration:
+		proc_type = p->procedure.node->procedure_declaration.procedure_type;
+		body = p->procedure.node->procedure_declaration.body;
+		break;
+	case AstNode_ProcedureLiteral:
+		proc_type = p->procedure.node->procedure_literal.type;
+		body = p->procedure.node->procedure_literal.body;
+		break;
+	default:
+		return;
+	}
+
+	if (body == NULL) {
+		// NOTE(bill): External procedure
+		return;
+	}
+
+	defer (gb_printf("build procedure %.*s\n", LIT(p->procedure.token.string)));
+
+
+	ir_begin_procedure_body(p);
+	ir_build_statement(p, body);
+	ir_end_procedure_body(p);
+}
+
+void ir_build_proc_decl(irModule *m, AstNode *decl) {
+	GB_ASSERT(decl != NULL);
+	auto *pd = &decl->procedure_declaration;
+	if (is_blank_identifier(pd->name))
+		return;
+
+	Entity *e = entity_of_identifier(m->checker, pd->name);
+	irValue *p = *map_get(&m->values, hash_pointer(e));
+	ir_build_procedure(m, p);
+}
+
+
+
+void generate_code(Codegen *c) {
+	gbAllocator a = gb_heap_allocator();
+
+	ir_module_create(&c->module);
+
+	for (isize i = 0; i < gb_array_count(c->module.values.entries); i++) {
+		irValue *v = c->module.values.entries[i].value;
+		switch (v->kind) {
+		case irValue_Procedure:
+			ir_build_proc_decl(&c->module, v->procedure.node);
+			break;
+		}
+	}
+}
+#endif
diff --git a/src/codegen/print.cpp b/src/codegen/print.cpp
new file mode 100644
index 000000000..6ce039e0b
--- /dev/null
+++ b/src/codegen/print.cpp
@@ -0,0 +1,401 @@
+void ssa_fprintf(gbFile *f, char *fmt, ...) {
+	va_list va;
+	va_start(va, fmt);
+	gb_fprintf_va(f, fmt, va);
+#if 1
+	gb_printf_va(fmt, va);
+#endif
+	va_end(va);
+}
+
+
+b32 ssa_valid_char(u8 c) {
+	if (gb_char_is_alphanumeric(c))
+		return true;
+
+	switch (c) {
+	case '$':
+	case '-':
+	case '.':
+	case '_':
+		return true;
+	}
+
+	return false;
+}
+
+void ssa_print_escape_string(gbFile *f, String name) {
+	isize extra = 0;
+	for (isize i = 0; i < name.len; i++) {
+		u8 c = name.text[i];
+		if (!ssa_valid_char(c))
+			extra += 2;
+	}
+
+	if (extra == 0) {
+		ssa_fprintf(f, "%.*s", LIT(name));
+		return;
+	}
+
+	char hex_table[] = "0123456789ABCDEF";
+	isize buf_len = name.len + extra;
+	u8 *buf = gb_alloc_array(gb_heap_allocator(), u8, buf_len);
+	defer (gb_free(gb_heap_allocator(), buf));
+
+	isize j = 0;
+	for (isize i = 0; i < name.len; i++) {
+		u8 c = name.text[i];
+		if (ssa_valid_char(c)) {
+			buf[j++] = c;
+		} else {
+			buf[j] = '\\';
+			buf[j+1] = hex_table[c >> 4];
+			buf[j+2] = hex_table[c & 0x0f];
+			j += 3;
+		}
+	}
+
+	gb_file_write(f, buf, buf_len);
+}
+
+
+
+void ssa_print_encoded_local(gbFile *f, String name) {
+	ssa_fprintf(f, "%%");
+	ssa_print_escape_string(f, name);
+}
+
+void ssa_print_encoded_global(gbFile *f, String name) {
+	ssa_fprintf(f, "@");
+	ssa_print_escape_string(f, name);
+}
+
+
+void ssa_print_type(gbFile *f, BaseTypeSizes s, Type *t) {
+	i64 word_bits = 8*s.word_size;
+	GB_ASSERT_NOT_NULL(t);
+	t = default_type(t);
+
+	switch (t->kind) {
+	case Type_Basic:
+		switch (t->basic.kind) {
+		case Basic_bool:   ssa_fprintf(f, "i1");                      break;
+		case Basic_i8:     ssa_fprintf(f, "i8");                      break;
+		case Basic_i16:    ssa_fprintf(f, "i16");                     break;
+		case Basic_i32:    ssa_fprintf(f, "i32");                     break;
+		case Basic_i64:    ssa_fprintf(f, "i64");                     break;
+		case Basic_u8:     ssa_fprintf(f, "i8");                      break;
+		case Basic_u16:    ssa_fprintf(f, "i16");                     break;
+		case Basic_u32:    ssa_fprintf(f, "i32");                     break;
+		case Basic_u64:    ssa_fprintf(f, "i64");                     break;
+		case Basic_f32:    ssa_fprintf(f, "float");                   break;
+		case Basic_f64:    ssa_fprintf(f, "double");                  break;
+		case Basic_rawptr: ssa_fprintf(f, "void*");                   break;
+		case Basic_string: ssa_fprintf(f, "{i8*, i%lld}", word_bits); break;
+		case Basic_int:    ssa_fprintf(f, "i%lld", word_bits);        break;
+		case Basic_uint:   ssa_fprintf(f, "i%lld", word_bits);        break;
+		}
+		break;
+	case Type_Array:
+		ssa_fprintf(f, "[%lld x ", t->array.count);
+		ssa_print_type(f, s, t->array.element);
+		ssa_fprintf(f, "]");
+		break;
+	case Type_Slice:
+		ssa_fprintf(f, "{");
+		ssa_print_type(f, s, t->slice.element);
+		ssa_fprintf(f, "*, %lld, %lld}", word_bits, word_bits);
+		break;
+	case Type_Structure:
+		ssa_fprintf(f, "{");
+		for (isize i = 0; i < t->structure.field_count; i++) {
+			if (i > 0) ssa_fprintf(f, ", ");
+			ssa_print_type(f, s, t->structure.fields[i]->type);
+		}
+		ssa_fprintf(f, "}");
+		break;
+	case Type_Pointer:
+		ssa_print_type(f, s, t->pointer.element);
+		ssa_fprintf(f, "*");
+		break;
+	case Type_Named:
+		ssa_print_encoded_local(f, t->named.name);
+		break;
+	case Type_Alias:
+		ssa_print_type(f, s, t->alias.base);
+		break;
+	case Type_Tuple:
+		if (t->tuple.variable_count == 1) {
+			ssa_print_type(f, s, t->tuple.variables[0]->type);
+		} else {
+			ssa_fprintf(f, "{");
+			for (isize i = 0; i < t->tuple.variable_count; i++) {
+				if (i > 0) ssa_fprintf(f, ", ");
+				ssa_print_type(f, s, t->tuple.variables[i]->type);
+			}
+			ssa_fprintf(f, "}");
+		}
+		break;
+	case Type_Procedure:
+		if (t->procedure.result_count == 0)
+			ssa_fprintf(f, "void");
+		else
+			ssa_print_type(f, s, t->procedure.results);
+		ssa_fprintf(f, " (");
+		for (isize i = 0; i < t->procedure.param_count; i++) {
+			if (i > 0) ssa_fprintf(f, ", ");
+			ssa_print_type(f, s, &t->procedure.params[i]);
+		}
+		ssa_fprintf(f, ")");
+		break;
+	}
+}
+
+void ssa_print_exact_value(gbFile *f, ssaModule *m, ExactValue value, Type *type) {
+	switch (value.kind) {
+	case ExactValue_Bool:
+		ssa_fprintf(f, (value.value_bool ? "true" : "false"));
+		break;
+	case ExactValue_String: {
+		ssa_fprintf(f, "{");
+		ssa_print_type(f, m->sizes, &basic_types[Basic_i8]);
+		ssa_fprintf(f, "* \"");
+		// TODO(bill): Make unquote string function
+		String unquoted = value.value_string;
+		unquoted.text++;
+		unquoted.len -= 2;
+		ssa_print_escape_string(f, unquoted);
+		ssa_fprintf(f, "\", ");
+		ssa_print_type(f, m->sizes, &basic_types[Basic_int]);
+		ssa_fprintf(f, " %td}", value.value_string.len);
+	} break;
+	case ExactValue_Integer:
+		ssa_fprintf(f, "%lld", value.value_integer);
+		break;
+	case ExactValue_Float: {
+		u64 u = 0;
+		if (is_type_float(type) && type->basic.kind == Basic_f32) {
+			// IMPORTANT NOTE(bill): LLVM requires all floating point constants to be
+			// a 64 bit number if bits_of(float type) <= 64.
+			// To overcome this problem, fill the "bottom" 32 bits with zeros
+			// https://groups.google.com/forum/#!topic/llvm-dev/IlqV3TbSk6M
+			f32 fp = cast(f32)value.value_float;
+			u = *cast(u32 *)&fp;
+			u <<= 32;
+
+		} else {
+			u = *cast(u64 *)&value.value_float;
+		}
+		ssa_fprintf(f, "0x%llx", u);
+	} break;
+	case ExactValue_Pointer:
+		if (value.value_float == NULL) {
+			ssa_fprintf(f, "null");
+		} else {
+			GB_PANIC("TODO(bill): ExactValue_Pointer");
+		}
+		break;
+	default:
+		GB_PANIC("Invalid ExactValue");
+		break;
+	}
+}
+
+
+void ssa_print_value(gbFile *f, ssaModule *m, ssaValue *value, Type *type_hint) {
+	if (value == NULL) {
+		ssa_fprintf(f, "!!!NULL_VALUE");
+		return;
+	}
+	switch (value->kind) {
+	case ssaValue_TypeName:
+		ssa_print_encoded_local(f, value->type_name->token.string);
+		break;
+	case ssaValue_Global:
+		ssa_print_encoded_global(f, value->global.entity->token.string);
+		break;
+	case ssaValue_Procedure:
+		ssa_print_encoded_global(f, value->procedure.entity->token.string);
+		break;
+	case ssaValue_Constant: {
+		ssa_print_exact_value(f, m, value->constant.value, type_hint);
+	} break;
+	case ssaValue_Instruction:
+		ssa_fprintf(f, "%%%d", value->id);
+		break;
+	}
+}
+
+void ssa_print_instruction(gbFile *f, ssaModule *m, ssaValue *value) {
+	GB_ASSERT(value->kind == ssaValue_Instruction);
+
+	ssa_fprintf(f, "\t");
+
+	ssaInstruction *instr = &value->instruction;
+	switch (instr->kind) {
+	case ssaInstruction_Local: {
+		Type *type = instr->local.entity->type;
+		ssa_fprintf(f, "%%%d = alloca ", value->id);
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, ", align %lld\n", type_align_of(m->sizes, gb_heap_allocator(), type));
+		ssa_fprintf(f, "\tstore ");
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, " zeroinitializer, ");
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, "* %%%d\n", value->id);
+	} break;
+
+	case ssaInstruction_Store: {
+		Type *type = ssa_value_type(instr->store.address);
+		ssa_fprintf(f, "store ");
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, " ");
+		ssa_print_value(f, m, instr->store.value, type);
+		ssa_fprintf(f, ", ");
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, "* ");
+		ssa_print_value(f, m, instr->store.address, type);
+		ssa_fprintf(f, "\n");
+	} break;
+
+	case ssaInstruction_Load: {
+		Type *type = ssa_value_type(instr->load.address);
+		ssa_fprintf(f, "%%%d = load ", value->id);
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, ", ");
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, "* ");
+		ssa_print_value(f, m, instr->load.address, type);
+		ssa_fprintf(f, "\n");
+	} break;
+
+
+	case ssaInstruction_BinaryOp: {
+		ssaBinaryOp *bo = &value->instruction.binary_op;
+		Type *type = ssa_value_type(bo->left);
+
+		if (is_type_float(type))
+			ssa_fprintf(f, "f");
+
+		switch (bo->op.kind) {
+		case Token_Add:    ssa_fprintf(f, "add"); break;
+		case Token_Sub:    ssa_fprintf(f, "sub"); break;
+		case Token_And:    ssa_fprintf(f, "and"); break;
+		case Token_Or:     ssa_fprintf(f, "or"); break;
+		case Token_Xor:    ssa_fprintf(f, "xor"); break;
+
+		case Token_AndNot: GB_PANIC("TODO(bill): print Token_AndNot");
+
+		case Token_Mul: ssa_fprintf(f, "mul"); break;
+
+		default: {
+			if (!is_type_float(type)) {
+				if (is_type_unsigned(type))
+					ssa_fprintf(f, "u");
+				else
+					ssa_fprintf(f, "s");
+			}
+
+			switch (bo->op.kind) {
+			case Token_Quo: ssa_fprintf(f, "div"); break;
+			case Token_Mod: ssa_fprintf(f, "rem"); break;
+			}
+		} break;
+		}
+
+		ssa_fprintf(f, " ");
+		ssa_print_type(f, m->sizes, type);
+		ssa_fprintf(f, " ");
+		ssa_print_value(f, m, bo->left, type);
+		ssa_fprintf(f, ", ");
+		ssa_print_value(f, m, bo->right, type);
+		ssa_fprintf(f, "\n");
+
+	} break;
+
+	default:
+		ssa_fprintf(f, "; <unknown instr> %d\n", instr->kind);
+		break;
+	}
+}
+
+void ssa_print_llvm_ir(gbFile *f, ssaModule *m) {
+	gb_printf("-- Printing LLVM-IR -- \n\n");
+	gb_for_array(member_index, m->members.entries) {
+		auto *entry = &m->members.entries[member_index];
+		ssaValue *v = entry->value;
+		switch (v->kind) {
+		case ssaValue_TypeName: {
+			ssa_print_encoded_local(f, v->type_name->token.string);
+			ssa_fprintf(f, " = type ");
+			ssa_print_type(f, m->sizes, get_base_type(v->type_name->type));
+			ssa_fprintf(f, "\n");
+		} break;
+
+		case ssaValue_Global: {
+			ssaGlobal *g = &v->global;
+			ssa_print_encoded_global(f, g->entity->token.string);
+			ssa_fprintf(f, " = global ");
+			ssa_print_type(f, m->sizes, get_base_type(g->entity->type));
+			ssa_fprintf(f, " ");
+			ssa_print_value(f, m, g->value, g->entity->type);
+			ssa_fprintf(f, ", align %td\n", type_align_of(m->sizes, gb_heap_allocator(), g->entity->type));
+		} break;
+
+		case ssaValue_Procedure: {
+			ssaProcedure *proc = &v->procedure;
+			if (proc->body == NULL) {
+				ssa_fprintf(f, "declare ");
+			} else {
+				ssa_fprintf(f, "define ");
+			}
+
+			auto *proc_type = &proc->entity->type->procedure;
+
+			if (proc_type->result_count == 0) {
+				ssa_fprintf(f, "void");
+			} else {
+				ssa_print_type(f, m->sizes, proc_type->results);
+			}
+
+			ssa_fprintf(f, " ");
+
+			ssa_print_encoded_global(f, proc->name);
+			ssa_fprintf(f, "(");
+
+			if (proc_type->param_count > 0) {
+				auto *params = &proc_type->params->tuple;
+				for (isize i = 0; i < params->variable_count; i++) {
+					Entity *e = params->variables[i];
+					if (i > 0)
+						ssa_fprintf(f, ", ");
+					ssa_print_type(f, m->sizes, e->type);
+					ssa_fprintf(f, " %%%.*s", LIT(e->token.string));
+				}
+			}
+
+			ssa_fprintf(f, ") ");
+
+ 			if (proc->body == NULL) {
+				ssa_fprintf(f, "\n");
+ 			} else {
+ 				ssa_fprintf(f, "{\n");
+ 				gb_for_array(i, proc->blocks) {
+ 					ssaBlock *block = &proc->blocks[i]->block;
+ 					ssa_fprintf(f, "%.*s:\n", LIT(block->label));
+ 					gb_for_array(j, block->instructions) {
+ 						ssaValue *value = block->instructions[j];
+ 						ssa_print_instruction(f, m, value);
+ 					}
+ 				}
+
+ 				if (proc_type->result_count == 0) {
+ 					ssa_fprintf(f, "\tret void\n");
+ 				}
+ 				ssa_fprintf(f, "}\n");
+ 			}
+
+		} break;
+		}
+	}
+}
diff --git a/src/codegen/ssa.cpp b/src/codegen/ssa.cpp
new file mode 100644
index 000000000..d17264f64
--- /dev/null
+++ b/src/codegen/ssa.cpp
@@ -0,0 +1,746 @@
+struct ssaModule;
+struct ssaProcedure;
+struct ssaBlock;
+struct ssaValue;
+
+
+struct ssaModule {
+	CheckerInfo *info;
+	BaseTypeSizes sizes;
+	gbAllocator allocator;
+
+	Map<ssaValue *> values;  // Key: Entity *
+	Map<ssaValue *> members; // Key: String
+	i32 global_string_index;
+};
+
+
+struct ssaBlock {
+	i32 id;
+	AstNode *node;
+	Scope *scope;
+	String label;
+	ssaProcedure *parent;
+
+	gbArray(ssaValue *) instructions;
+	gbArray(ssaValue *) values;
+};
+
+struct ssaProcedure {
+	ssaModule *module;
+	String name;
+	Entity *entity;
+	DeclarationInfo *decl;
+	AstNode *type_expr;
+	AstNode *body;
+
+	gbArray(ssaValue *) blocks;
+	ssaBlock *curr_block;
+};
+
+
+struct ssaLocal {
+	Entity *entity;
+};
+struct ssaGlobal {
+	b32 generated;
+	Entity *entity;
+	ssaValue *value;
+};
+struct ssaStore {
+	ssaValue *address;
+	ssaValue *value;
+};
+struct ssaLoad {
+	ssaValue *address;
+};
+struct ssaBinaryOp {
+	Token op;
+	ssaValue *left, *right;
+};
+struct ssaGetElementPtr {
+	ssaValue *address;
+	Type *result_type;
+	Type *element_type;
+	gbArray(ssaValue *) indices;
+};
+
+enum ssaInstructionKind {
+	ssaInstruction_Invalid,
+
+	ssaInstruction_Local,
+	ssaInstruction_Store,
+	ssaInstruction_Load,
+	ssaInstruction_GetElementPtr,
+
+	ssaInstruction_BinaryOp,
+
+	ssaInstruction_Count,
+};
+
+struct ssaInstruction {
+	ssaInstructionKind kind;
+
+	ssaBlock *parent;
+	Type *type;
+	TokenPos pos;
+
+	union {
+		ssaLocal         local;
+		ssaStore         store;
+		ssaLoad          load;
+		ssaGetElementPtr get_element_ptr;
+
+		ssaBinaryOp      binary_op;
+	};
+};
+
+
+enum ssaValueKind {
+	ssaValue_Invalid,
+
+	ssaValue_TypeName,
+	ssaValue_Global,
+	ssaValue_Procedure,
+	ssaValue_Constant,
+
+	ssaValue_Block,
+	ssaValue_Instruction,
+
+	ssaValue_Count,
+};
+
+struct ssaValue {
+	ssaValueKind kind;
+	i32 id;
+
+	union {
+		Entity *       type_name;
+		ssaGlobal      global;
+		ssaProcedure   procedure;
+		TypeAndValue   constant;
+		ssaBlock       block;
+		ssaInstruction instruction;
+	};
+};
+
+enum ssaLvalueKind {
+	ssaLvalue_Blank,
+	ssaLvalue_Address,
+
+	ssaLvalue_Count,
+};
+
+struct ssaLvalue {
+	ssaLvalueKind kind;
+	union {
+		struct {} blank;
+		struct {
+			ssaValue *value;
+			AstNode *expr;
+		} address;
+	};
+};
+
+void ssa_module_init(ssaModule *m, Checker *c) {
+	m->allocator = gb_heap_allocator();
+	m->info = &c->info;
+	m->sizes = c->sizes;
+
+	map_init(&m->values,  m->allocator);
+	map_init(&m->members, m->allocator);
+}
+
+void ssa_module_destroy(ssaModule *m) {
+	map_destroy(&m->values);
+	map_destroy(&m->members);
+}
+
+void ssa_module_add_value(ssaModule *m, Entity *e, ssaValue *v) {
+	map_set(&m->values, hash_pointer(e), v);
+}
+
+
+Type *ssa_value_type(ssaValue *value);
+
+Type *ssa_instruction_type(ssaInstruction *instr) {
+	switch (instr->kind) {
+	case ssaInstruction_Local:
+		return instr->local.entity->type;
+	case ssaInstruction_Store:
+		return ssa_value_type(instr->store.address);
+	case ssaInstruction_Load:
+		return ssa_value_type(instr->load.address);
+	}
+	return NULL;
+}
+
+Type *ssa_value_type(ssaValue *value) {
+	switch (value->kind) {
+	case ssaValue_TypeName:
+		return value->type_name->type;
+	case ssaValue_Global:
+		return value->global.entity->type;
+	case ssaValue_Procedure:
+		return value->procedure.entity->type;
+	case ssaValue_Constant:
+		return value->constant.type;
+	case ssaValue_Instruction:
+		return ssa_instruction_type(&value->instruction);
+	}
+	return NULL;
+}
+
+
+
+
+
+
+
+
+
+
+
+ssaValue *ssa_alloc_value(gbAllocator a, ssaValueKind kind) {
+	ssaValue *v = gb_alloc_item(a, ssaValue);
+	v->kind = kind;
+	return v;
+}
+
+ssaValue *ssa_alloc_instruction(gbAllocator a, ssaInstructionKind kind) {
+	ssaValue *v = ssa_alloc_value(a, ssaValue_Instruction);
+	v->instruction.kind = kind;
+	return v;
+}
+
+ssaValue *ssa_make_value_type_name(gbAllocator a, Entity *e) {
+	ssaValue *v = ssa_alloc_value(a, ssaValue_TypeName);
+	v->type_name = e;
+	return v;
+}
+
+ssaValue *ssa_make_value_global(gbAllocator a, Entity *e, ssaValue *value) {
+	ssaValue *v = ssa_alloc_value(a, ssaValue_Global);
+	v->global.entity = e;
+	v->global.value  = value;
+	return v;
+}
+
+
+
+ssaValue *ssa_make_instruction_local(ssaProcedure *p, Entity *e) {
+	ssaValue *v = ssa_alloc_instruction(p->module->allocator, ssaInstruction_Local);
+	ssaInstruction *i = &v->instruction;
+	i->local.entity = e;
+	if (p->curr_block) {
+		gb_array_append(p->curr_block->values, v);
+	}
+	ssa_module_add_value(p->module, e, v);
+	return v;
+}
+
+
+ssaValue *ssa_make_instruction_store(ssaProcedure *p, ssaValue *address, ssaValue *value) {
+	ssaValue *v = ssa_alloc_instruction(p->module->allocator, ssaInstruction_Store);
+	ssaInstruction *i = &v->instruction;
+	i->store.address = address;
+	i->store.value = value;
+	if (p->curr_block) {
+		gb_array_append(p->curr_block->values, v);
+	}
+	return v;
+}
+
+ssaValue *ssa_make_instruction_load(ssaProcedure *p, ssaValue *address) {
+	ssaValue *v = ssa_alloc_instruction(p->module->allocator, ssaInstruction_Load);
+	ssaInstruction *i = &v->instruction;
+	i->load.address = address;
+	if (p->curr_block) {
+		gb_array_append(p->curr_block->values, v);
+	}
+	return v;
+}
+
+ssaValue *ssa_make_instruction_get_element_ptr(ssaProcedure *p, ssaValue *address) {
+	ssaValue *v = ssa_alloc_instruction(p->module->allocator, ssaInstruction_GetElementPtr);
+	ssaInstruction *i = &v->instruction;
+	i->get_element_ptr.address = address;
+	if (p->curr_block) {
+		gb_array_append(p->curr_block->values, v);
+	}
+	return v;
+}
+
+ssaValue *ssa_make_instruction_binary_op(ssaProcedure *p, Token op, ssaValue *left, ssaValue *right) {
+	ssaValue *v = ssa_alloc_instruction(p->module->allocator, ssaInstruction_BinaryOp);
+	ssaInstruction *i = &v->instruction;
+	i->binary_op.op = op;
+	i->binary_op.left = left;
+	i->binary_op.right = right;
+	if (p->curr_block) {
+		gb_array_append(p->curr_block->values, v);
+	}
+	return v;
+}
+
+
+ssaValue *ssa_make_value_constant(gbAllocator a, Type *type, ExactValue value) {
+	ssaValue *v = ssa_alloc_value(a, ssaValue_Constant);
+	v->constant.type  = type;
+	v->constant.value = value;
+	return v;
+}
+
+ssaValue *ssa_make_value_procedure(gbAllocator a, Entity *e, DeclarationInfo *decl, ssaModule *m) {
+	ssaValue *v = ssa_alloc_value(a, ssaValue_Procedure);
+	v->procedure.module = m;
+	v->procedure.entity = e;
+	v->procedure.decl   = decl;
+	v->procedure.name   = e->token.string;
+	return v;
+}
+
+ssaValue *ssa_make_value_block(gbAllocator a, ssaProcedure *proc, AstNode *node, Scope *scope, String label) {
+	ssaValue *v = ssa_alloc_value(a, ssaValue_Block);
+	v->block.label = label;
+	v->block.node = node;
+	v->block.scope = scope;
+	v->block.parent = proc;
+
+	gb_array_init(v->block.instructions, gb_heap_allocator());
+	gb_array_init(v->block.values,       gb_heap_allocator());
+
+	return v;
+}
+
+
+
+ssaValue *ssa_add_global_string(ssaProcedure *proc, ExactValue value) {
+	GB_ASSERT(value.kind == ExactValue_String);
+	gbAllocator a = gb_heap_allocator();
+
+
+	isize max_len = 4+8+1;
+	u8 *str = cast(u8 *)gb_alloc_array(a, u8, max_len);
+	isize len = gb_snprintf(cast(char *)str, max_len, ".str%x", proc->module->global_string_index);
+	proc->module->global_string_index++;
+
+	String name = make_string(str, len-1);
+	Token token = {Token_String};
+	token.string = name;
+	Type *type = &basic_types[Basic_string];
+	Entity *entity = make_entity_constant(a, NULL, token, type, value);
+	ssaValue *v = ssa_make_value_constant(a, type, value);
+
+
+	ssaValue *g = ssa_make_value_global(a, entity, v);
+	g->global.generated = true;
+
+	map_set(&proc->module->values, hash_pointer(entity), g);
+	map_set(&proc->module->members, hash_string(name), g);
+
+	return g;
+}
+
+
+ssaValue *ssa_add_block(ssaProcedure *proc, AstNode *node, String label) {
+	gbAllocator a = proc->module->allocator;
+	Scope *scope = NULL;
+	Scope **found = map_get(&proc->module->info->scopes, hash_pointer(node));
+	if (found) scope = *found;
+	ssaValue *block = ssa_make_value_block(a, proc, node, scope, label);
+	gb_array_append(proc->blocks, block);
+	return block;
+}
+
+
+
+void ssa_begin_procedure_body(ssaProcedure *proc) {
+	gb_array_init(proc->blocks, gb_heap_allocator());
+	ssaValue *b = ssa_add_block(proc, proc->body, make_string("entry"));
+	proc->curr_block = &b->block;
+}
+
+
+void ssa_end_procedure_body(ssaProcedure *proc) {
+
+// Number registers
+	i32 reg_id = 0;
+	gb_for_array(i, proc->blocks) {
+		ssaBlock *b = &proc->blocks[i]->block;
+		gb_for_array(j, b->instructions) {
+			ssaValue *value = b->instructions[j];
+			ssaInstruction *instr = &value->instruction;
+			if (instr->kind == ssaInstruction_Store) {
+				continue;
+			}
+			value->id = reg_id;
+			reg_id++;
+		}
+	}
+}
+
+
+b32 ssa_is_blank_identifier(AstNode *i) {
+	GB_ASSERT(i->kind == AstNode_Identifier);
+	return are_strings_equal(i->identifier.token.string, make_string("_"));
+}
+
+
+ssaValue *ssa_block_emit(ssaBlock *b, ssaValue *instr) {
+	instr->instruction.parent = b;
+	gb_array_append(b->instructions, instr);
+	return instr;
+}
+
+ssaValue *ssa_emit(ssaProcedure *proc, ssaValue *instr) {
+	return ssa_block_emit(proc->curr_block, instr);
+}
+
+
+ssaValue *ssa_add_local(ssaProcedure *proc, Entity *e) {
+	ssaValue *instr = ssa_make_instruction_local(proc, e);
+	ssa_emit(proc, instr);
+	return instr;
+}
+
+ssaValue *ssa_add_local_for_identifier(ssaProcedure *proc, AstNode *name) {
+	Entity **found = map_get(&proc->module->info->definitions, hash_pointer(name));
+	if (found) {
+		return ssa_add_local(proc, *found);
+	}
+	return NULL;
+}
+
+
+ssaValue *ssa_emit_store(ssaProcedure *p, ssaValue *address, ssaValue *value) {
+	ssaValue *store = ssa_make_instruction_store(p, address, value);
+	ssa_emit(p, store);
+	return store;
+}
+
+ssaValue *ssa_emit_load(ssaProcedure *p, ssaValue *address) {
+	ssaValue *v = ssa_make_instruction_load(p, address);
+	ssa_emit(p, v);
+	return v;
+}
+
+ssaValue *ssa_lvalue_store(ssaLvalue lval, ssaProcedure *p, ssaValue *value) {
+	switch (lval.kind) {
+	case ssaLvalue_Address:
+		return ssa_emit_store(p, lval.address.value, value);
+	}
+	GB_PANIC("Illegal lvalue store");
+	return NULL;
+}
+
+ssaValue *ssa_lvalue_load(ssaLvalue lval, ssaProcedure *p) {
+	switch (lval.kind) {
+	case ssaLvalue_Address:
+		return ssa_emit_load(p, lval.address.value);
+	}
+	GB_PANIC("Illegal lvalue load");
+	return NULL;
+}
+
+
+ssaValue *ssa_lvalue_address(ssaLvalue lval, ssaProcedure *p) {
+	switch (lval.kind) {
+	case ssaLvalue_Address:
+		return lval.address.value;
+	}
+	return NULL;
+}
+
+ssaValue *ssa_build_expression(ssaProcedure *proc, AstNode *expr);
+ssaValue *ssa_build_single_expression(ssaProcedure *proc, AstNode *expr, TypeAndValue *tv);
+
+ssaValue *ssa_emit_conversion(ssaProcedure *proc, ssaValue *value, Type *a_type) {
+	Type *b_type = ssa_value_type(value);
+	if (are_types_identical(a_type, b_type))
+		return value;
+
+	Type *a = get_base_type(a_type);
+	Type *b = get_base_type(b_type);
+
+	if (value->kind == ssaValue_Constant) {
+		if (a->kind == Type_Basic)
+			return ssa_make_value_constant(proc->module->allocator, a_type, value->constant.value);
+	}
+
+	GB_PANIC("TODO(bill): ssa_emit_conversion");
+
+	return NULL;
+}
+
+ssaValue *ssa_emit_arith(ssaProcedure *proc, Token op, ssaValue *left, ssaValue *right, Type *type) {
+	switch (op.kind) {
+	case Token_Add:
+	case Token_Sub:
+	case Token_Mul:
+	case Token_Quo:
+	case Token_Mod:
+	case Token_And:
+	case Token_Or:
+	case Token_Xor:
+	case Token_AndNot:
+		left  = ssa_emit_conversion(proc, left, type);
+		right = ssa_emit_conversion(proc, right, type);
+		break;
+	}
+
+	ssaValue *v = ssa_make_instruction_binary_op(proc, op, left, right);
+	return ssa_emit(proc, v);
+}
+
+ssaValue *ssa_build_single_expression(ssaProcedure *proc, AstNode *expr, TypeAndValue *tv) {
+	switch (expr->kind) {
+	case AstNode_Identifier: {
+		Entity *e = *map_get(&proc->module->info->uses, hash_pointer(expr));
+		if (e->kind == Entity_Builtin) {
+			// TODO(bill): Entity_Builtin
+			return NULL;
+		}
+
+		auto *found = map_get(&proc->module->values, hash_pointer(e));
+		if (found) {
+			return ssa_emit_load(proc, *found);
+		}
+	} break;
+
+	case AstNode_UnaryExpression: {
+		auto *ue = &expr->unary_expression;
+		switch (ue->op.kind) {
+		case Token_Add:
+			return ssa_build_expression(proc, ue->operand);
+		case Token_Sub:
+			return NULL;
+		case Token_Xor:
+			return NULL;
+		case Token_Not:
+			return NULL;
+		case Token_Pointer:
+			return NULL;
+		}
+	} break;
+
+	case AstNode_BinaryExpression: {
+		auto *be = &expr->binary_expression;
+		switch (be->op.kind) {
+		case Token_Add:
+		case Token_Sub:
+		case Token_Mul:
+		case Token_Quo:
+		case Token_Mod:
+		case Token_And:
+		case Token_Or:
+		case Token_Xor:
+		case Token_AndNot:
+			return ssa_emit_arith(proc, be->op,
+			                      ssa_build_expression(proc, be->left),
+			                      ssa_build_expression(proc, be->right),
+			                      tv->type);
+		}
+	} break;
+	case AstNode_ProcedureLiteral:
+		break;
+	case AstNode_CastExpression:
+		break;
+	case AstNode_CallExpression:
+		break;
+	case AstNode_SliceExpression:
+		break;
+	case AstNode_IndexExpression:
+		break;
+	case AstNode_SelectorExpression:
+		break;
+	}
+
+	GB_PANIC("Unexpected expression");
+	return NULL;
+}
+
+
+ssaValue *ssa_build_expression(ssaProcedure *proc, AstNode *expr) {
+	expr = unparen_expression(expr);
+
+	TypeAndValue *tv = map_get(&proc->module->info->types, hash_pointer(expr));
+	if (tv) {
+		if (tv->value.kind != ExactValue_Invalid) {
+			if (tv->value.kind == ExactValue_String) {
+				ssaValue *global_str = ssa_add_global_string(proc, tv->value);
+				return ssa_emit_load(proc, global_str);
+			}
+			return ssa_make_value_constant(proc->module->allocator, tv->type, tv->value);
+		}
+
+		ssaValue *value = NULL;
+		if (tv->mode == Addressing_Variable) {
+			gb_printf("!Addressable!\n");
+			// TODO(bill): Addressing_Variable
+		} else {
+			value = ssa_build_single_expression(proc, expr, tv);
+		}
+
+		return value;
+	}
+	return NULL;
+}
+
+
+ssaLvalue ssa_build_address(ssaProcedure *proc, AstNode *expr) {
+	switch (expr->kind) {
+	case AstNode_Identifier: {
+		if (!ssa_is_blank_identifier(expr)) {
+			Entity *e = entity_of_identifier(proc->module->info, expr);
+
+			ssaLvalue val = {ssaLvalue_Address};
+			val.address.expr = expr;
+			ssaValue **found = map_get(&proc->module->values, hash_pointer(e));
+			if (found) {
+				val.address.value = *found;
+			}
+			return val;
+		}
+	} break;
+
+	case AstNode_ParenExpression:
+		return ssa_build_address(proc, unparen_expression(expr));
+
+	case AstNode_DereferenceExpression: {
+		ssaLvalue val = {ssaLvalue_Address};
+		val.address.value = ssa_build_expression(proc, expr);
+		val.address.expr  = expr;
+		return val;
+	} break;
+
+	case AstNode_SelectorExpression:
+		break;
+
+	case AstNode_IndexExpression:
+		break;
+
+	// TODO(bill): Others address
+	}
+
+	ssaLvalue blank = {ssaLvalue_Blank};
+	return blank;
+}
+
+void ssa_build_statement(ssaProcedure *proc, AstNode *s);
+
+void ssa_build_statement_list(ssaProcedure *proc, AstNode *list) {
+	for (AstNode *stmt = list ; stmt != NULL; stmt = stmt->next)
+		ssa_build_statement(proc, stmt);
+}
+
+void ssa_build_statement(ssaProcedure *proc, AstNode *s) {
+	switch (s->kind) {
+	case AstNode_EmptyStatement:
+		break;
+	case AstNode_VariableDeclaration: {
+		auto *vd = &s->variable_declaration;
+		if (vd->kind == Declaration_Mutable) {
+			if (vd->name_count == vd->value_count) { // 1:1 assigment
+
+			} else if (vd->value_count == 0) { // declared and zero-initialized
+				for (AstNode *name = vd->name_list; name != NULL; name = name->next) {
+					if (!ssa_is_blank_identifier(name)) {
+						// TODO(bill): add local
+						ssa_add_local_for_identifier(proc, name);
+					}
+				}
+			} else { // Tuple(s)
+				GB_PANIC("TODO(bill): tuple assignment variable declaration");
+			}
+		}
+	} break;
+
+	case AstNode_AssignStatement: {
+		auto *assign = &s->assign_statement;
+		switch (assign->op.kind) {
+		case Token_Eq: {
+			gbArray(ssaLvalue) lvals;
+			gb_array_init(lvals, gb_heap_allocator());
+			defer (gb_array_free(lvals));
+
+			for (AstNode *lhs = assign->lhs_list;
+			     lhs != NULL;
+			     lhs = lhs->next) {
+				ssaLvalue lval = {};
+				if (!ssa_is_blank_identifier(lhs)) {
+					lval = ssa_build_address(proc, lhs);
+				}
+				gb_array_append(lvals, lval);
+			}
+
+			if (assign->lhs_count == assign->rhs_count) {
+				if (assign->lhs_count == 1) {
+					AstNode *lhs = assign->lhs_list;
+					AstNode *rhs = assign->rhs_list;
+					ssaValue *init = ssa_build_expression(proc, rhs);
+					ssa_lvalue_store(lvals[0], proc, init);
+				} else {
+					GB_PANIC("TODO(bill): parallel assignment");
+				}
+			} else {
+					GB_PANIC("TODO(bill): tuple assignment");
+			}
+
+		} break;
+
+		default: // +=, -=, etc
+			break;
+		}
+	} break;
+
+	case AstNode_ExpressionStatement:
+		ssa_build_expression(proc, s->expression_statement.expression);
+		break;
+
+	case AstNode_BlockStatement:
+		ssa_build_statement_list(proc, s->block_statement.list);
+		break;
+	}
+}
+
+
+
+void ssa_build_procedure(ssaValue *value) {
+	ssaProcedure *proc = &value->procedure;
+
+	gb_printf("Building %.*s: %.*s\n", LIT(entity_strings[proc->entity->kind]), LIT(proc->name));
+
+
+	AstNode *proc_decl = proc->decl->proc_decl;
+	switch (proc_decl->kind) {
+	case AstNode_ProcedureDeclaration:
+		proc->type_expr = proc_decl->procedure_declaration.type;
+		proc->body = proc_decl->procedure_declaration.body;
+		break;
+	default:
+		return;
+	}
+
+	if (proc->body == NULL) {
+		// TODO(bill): External procedure
+		return;
+	}
+
+
+	ssa_begin_procedure_body(proc);
+	ssa_build_statement(proc, proc->body);
+	ssa_end_procedure_body(proc);
+
+}
+
+
+
+
+
+
+
+
+
+
+
diff --git a/src/codegen/value.cpp b/src/codegen/value.cpp
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/src/codegen/value.cpp