`#soa[]Type` (Experimental)

5 files changed, 354 insertions, 30 deletions

diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 85ac17300..54ac12aac 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -92,6 +92,10 @@ bool abi_compat_return_by_pointer(gbAllocator a, ProcCallingConvention cc, Type
 void set_procedure_abi_types(gbAllocator a, Type *type);
 void check_assignment_error_suggestion(CheckerContext *c, Operand *o, Type *type);
 
+
+Type *make_soa_struct_slice(CheckerContext *ctx, Ast *array_typ_expr, Ast *elem_expr, Type *elem);
+
+
 Entity *entity_from_expr(Ast *expr) {
 	expr = unparen_expr(expr);
 	switch (expr->kind) {
@@ -3228,6 +3232,8 @@ Entity *check_selector(CheckerContext *c, Operand *operand, Ast *node, Type *typ
 			}
 		} else if (operand->mode == Addressing_MapIndex) {
 			operand->mode = Addressing_Value;
+		} else if (entity->flags & EntityFlag_SoaPtrField) {
+			operand->mode = Addressing_SoaVariable;
 		} else if (sel.indirect || operand->mode != Addressing_Value || operand->mode == Addressing_SoaVariable) {
 			operand->mode = Addressing_Variable;
 		} else {
@@ -6739,7 +6745,7 @@ void check_expr_with_type_hint(CheckerContext *c, Operand *o, Ast *e, Type *t) {
 	}
 }
 
-bool check_set_index_data(Operand *o, Type *t, bool indirection, i64 *max_count) {
+bool check_set_index_data(Operand *o, Type *t, bool indirection, i64 *max_count, Type *original_type) {
 	switch (t->kind) {
 	case Type_Basic:
 		if (t->Basic.kind == Basic_string) {
@@ -6796,6 +6802,15 @@ bool check_set_index_data(Operand *o, Type *t, bool indirection, i64 *max_count)
 		return false;
 	}
 
+	if (is_type_pointer(original_type) && indirection) {
+		Type *ptr = base_type(original_type);
+		if (ptr->kind == Type_Pointer && o->mode == Addressing_SoaVariable) {
+			o->type = ptr->Pointer.elem;
+			o->mode = Addressing_Value;
+			return true;
+		}
+	}
+
 	return false;
 }
 
@@ -7973,7 +7988,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 		}
 
 		i64 max_count = -1;
-		bool valid = check_set_index_data(o, t, is_ptr, &max_count);
+		bool valid = check_set_index_data(o, t, is_ptr, &max_count, o->type);
 
 		if (is_const) {
 			valid = false;
@@ -8055,6 +8070,13 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			valid = true;
 			o->type = alloc_type_slice(t->DynamicArray.elem);
 			break;
+
+		case Type_Struct:
+			if (is_type_soa_struct(t)) {
+				valid = true;
+				o->type = make_soa_struct_slice(c, nullptr, nullptr, t->Struct.soa_elem);
+			}
+			break;
 		}
 
 		if (!valid) {
diff --git a/src/check_type.cpp b/src/check_type.cpp
index aa5a32905..6a3a000c7 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -2702,6 +2702,108 @@ void check_map_type(CheckerContext *ctx, Type *type, Ast *node) {
 	// error(node, "'map' types are not yet implemented");
 }
 
+Type *make_soa_struct_slice(CheckerContext *ctx, Ast *array_typ_expr, Ast *elem_expr, Type *elem) {
+	Type *bt_elem = base_type(elem);
+	if (!is_type_struct(elem) && !is_type_raw_union(elem) && !(is_type_array(elem) && bt_elem->Array.count <= 4)) {
+		GB_ASSERT(elem_expr != nullptr);
+
+		gbString str = type_to_string(elem);
+		error(elem_expr, "Invalid type for an #soa array, expected a struct or array of length 4 or below, got '%s'", str);
+		gb_string_free(str);
+		return alloc_type_slice(elem);
+	}
+
+	Type *soa_struct = nullptr;
+	Scope *scope = nullptr;
+
+	if (is_type_array(elem)) {
+		Type *old_array = base_type(elem);
+		isize field_count = old_array->Array.count;
+
+		soa_struct = alloc_type_struct();
+		soa_struct->Struct.fields = array_make<Entity *>(heap_allocator(), field_count+1);
+		soa_struct->Struct.tags = array_make<String>(heap_allocator(), field_count+1);
+		soa_struct->Struct.node = array_typ_expr;
+		soa_struct->Struct.soa_kind = StructSoa_Slice;
+		soa_struct->Struct.soa_elem = elem;
+		soa_struct->Struct.soa_count = 0;
+
+		scope = create_scope(ctx->scope, ctx->allocator);
+		soa_struct->Struct.scope = scope;
+
+		String params_xyzw[4] = {
+			str_lit("x"),
+			str_lit("y"),
+			str_lit("z"),
+			str_lit("w")
+		};
+
+		for (i64 i = 0; i < field_count; i++) {
+			Type *array_type = alloc_type_pointer(old_array->Array.elem);
+			Token token = {};
+			token.string = params_xyzw[i];
+
+			Entity *new_field = alloc_entity_field(scope, token, array_type, false, cast(i32)i);
+			new_field->flags |= EntityFlag_SoaPtrField;
+			soa_struct->Struct.fields[i] = new_field;
+			add_entity(ctx->checker, scope, nullptr, new_field);
+			add_entity_use(ctx, nullptr, new_field);
+		}
+
+		Entity *len_field = alloc_entity_field(scope, empty_token, t_int, false, cast(i32)field_count);
+		soa_struct->Struct.fields[field_count] = len_field;
+		add_entity(ctx->checker, scope, nullptr, len_field);
+		add_entity_use(ctx, nullptr, len_field);
+
+
+	} else {
+		GB_ASSERT(is_type_struct(elem));
+
+		Type *old_struct = base_type(elem);
+		isize field_count = old_struct->Struct.fields.count;
+
+		soa_struct = alloc_type_struct();
+		soa_struct->Struct.fields = array_make<Entity *>(heap_allocator(), field_count+1);
+		soa_struct->Struct.tags = array_make<String>(heap_allocator(), old_struct->Struct.tags.count+1);
+		soa_struct->Struct.node = array_typ_expr;
+		soa_struct->Struct.soa_kind = StructSoa_Slice;
+		soa_struct->Struct.soa_elem = elem;
+		soa_struct->Struct.soa_count = 0;
+
+		scope = create_scope(old_struct->Struct.scope->parent, ctx->allocator);
+		soa_struct->Struct.scope = scope;
+
+		for_array(i, old_struct->Struct.fields) {
+			Entity *old_field = old_struct->Struct.fields[i];
+			if (old_field->kind == Entity_Variable) {
+				Type *array_type = alloc_type_pointer(old_field->type);
+				Entity *new_field = alloc_entity_field(scope, old_field->token, array_type, false, old_field->Variable.field_src_index);
+				new_field->flags |= EntityFlag_SoaPtrField;
+				soa_struct->Struct.fields[i] = new_field;
+				add_entity(ctx->checker, scope, nullptr, new_field);
+			} else {
+				soa_struct->Struct.fields[i] = old_field;
+			}
+
+			soa_struct->Struct.tags[i] = old_struct->Struct.tags[i];
+		}
+
+		Entity *len_field = alloc_entity_field(scope, empty_token, t_int, false, cast(i32)field_count);
+		soa_struct->Struct.fields[field_count] = len_field;
+		add_entity(ctx->checker, scope, nullptr, len_field);
+		add_entity_use(ctx, nullptr, len_field);
+	}
+
+	Token token = {};
+	token.string = str_lit("Base_Type");
+	Entity *base_type_entity = alloc_entity_type_name(scope, token, elem, EntityState_Resolved);
+	add_entity(ctx->checker, scope, nullptr, base_type_entity);
+
+	add_type_info_type(ctx, soa_struct);
+
+	return soa_struct;
+}
+
 
 
 bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_type) {
@@ -2983,14 +3085,27 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 
 					*type = alloc_type_simd_vector(count, elem);
 				} else {
-					GB_PANIC("Unhandled array type tag %.*s", LIT(name));
+					error(at->tag, "Invalid tag applied to array, got #%.*s", LIT(name));
+					*type = alloc_type_array(elem, count, generic_type);
 				}
 			} else {
 				*type = alloc_type_array(elem, count, generic_type);
 			}
 		} else {
 			Type *elem = check_type(ctx, at->elem);
-			*type = alloc_type_slice(elem);
+
+			if (at->tag != nullptr) {
+				GB_ASSERT(at->tag->kind == Ast_BasicDirective);
+				String name = at->tag->BasicDirective.name;
+				if (name == "soa") {
+					*type = make_soa_struct_slice(ctx, e, at->elem, elem);
+				} else {
+					error(at->tag, "Invalid tag applied to array, got #%.*s", LIT(name));
+					*type = alloc_type_slice(elem);
+				}
+			} else {
+				*type = alloc_type_slice(elem);
+			}
 		}
 	array_end:
 		set_base_type(named_type, *type);
diff --git a/src/entity.cpp b/src/entity.cpp
index bbea68e8b..c433d98cb 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -51,8 +51,10 @@ enum EntityFlag {
 
 	EntityFlag_ImplicitReference = 1<<17, // NOTE(bill): equivalent to `const &` in C++
 
-	EntityFlag_CVarArg       = 1<<20,
-	EntityFlag_AutoCast      = 1<<21,
+	EntityFlag_SoaPtrField   = 1<<19, // to allow s.x[0] where `s.x` is a pointer rather than a slice
+
+	EntityFlag_CVarArg       = 1<<21,
+	EntityFlag_AutoCast      = 1<<22,
 };
 
 enum EntityState {
diff --git a/src/ir.cpp b/src/ir.cpp
index 3343021f4..89f570659 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -3447,6 +3447,73 @@ irValue *ir_insert_dynamic_map_key_and_value(irProcedure *proc, irValue *addr, T
 
 
 
+irValue *ir_soa_struct_len(irProcedure *proc, irValue *value) {
+	Type *t = base_type(ir_type(value));
+	bool is_ptr = false;
+	if (is_type_pointer(t)) {
+		is_ptr = true;
+		t = base_type(type_deref(t));
+	}
+
+
+	if (t->Struct.soa_kind == StructSoa_Fixed) {
+		return ir_const_int(t->Struct.soa_count);
+	}
+
+	GB_ASSERT(t->Struct.soa_kind == StructSoa_Slice ||
+	          t->Struct.soa_kind == StructSoa_Dynamic);
+
+	isize n = 0;
+	Type *elem = base_type(t->Struct.soa_elem);
+	if (elem->kind == Type_Struct) {
+		n = elem->Struct.fields.count;
+	} else if (elem->kind == Type_Array) {
+		n = elem->Array.count;
+	} else {
+		GB_PANIC("Unreachable");
+	}
+
+	if (is_ptr) {
+		irValue *v = ir_emit_struct_ep(proc, value, cast(i32)n);
+		return ir_emit_load(proc, v);
+	}
+	return ir_emit_struct_ev(proc, value, cast(i32)n);
+}
+
+irValue *ir_soa_struct_cap(irProcedure *proc, irValue *value) {
+	Type *t = base_type(ir_type(value));
+
+	bool is_ptr = false;
+	if (is_type_pointer(t)) {
+		is_ptr = true;
+		t = base_type(type_deref(t));
+	}
+
+	if (t->Struct.soa_kind == StructSoa_Fixed) {
+		return ir_const_int(t->Struct.soa_count);
+	}
+
+	GB_ASSERT(t->Struct.soa_kind == StructSoa_Dynamic);
+
+	isize n = 0;
+	Type *elem = base_type(t->Struct.soa_elem);
+	if (elem->kind == Type_Struct) {
+		n = elem->Struct.fields.count+1;
+	} else if (elem->kind == Type_Array) {
+		n = elem->Array.count+1;
+	} else {
+		GB_PANIC("Unreachable");
+	}
+
+	if (is_ptr) {
+		irValue *v = ir_emit_struct_ep(proc, value, cast(i32)n);
+		return ir_emit_load(proc, v);
+	}
+	return ir_emit_struct_ev(proc, value, cast(i32)n);
+}
+
+
+
 void ir_addr_store(irProcedure *proc, irAddr const &addr, irValue *value) {
 	if (addr.addr == nullptr) {
 		return;
@@ -3568,7 +3635,7 @@ void ir_addr_store(irProcedure *proc, irAddr const &addr, irValue *value) {
 		value = ir_emit_conv(proc, value, t->Struct.soa_elem);
 
 		irValue *index = addr.soa.index;
-		if (index->kind != irValue_Constant) {
+		if (index->kind != irValue_Constant || t->Struct.soa_kind != StructSoa_Fixed) {
 			Type *t = base_type(type_deref(ir_type(addr.addr)));
 			GB_ASSERT(t->kind == Type_Struct && t->Struct.soa_kind != StructSoa_None);
 			i64 count = t->Struct.soa_count;
@@ -3697,27 +3764,53 @@ irValue *ir_addr_load(irProcedure *proc, irAddr const &addr) {
 		t = base_type(t);
 		GB_ASSERT(t->kind == Type_Struct && t->Struct.soa_kind != StructSoa_None);
 		Type *elem = t->Struct.soa_elem;
-		i32 count = cast(i32)t->Struct.soa_count;
+
+		irValue *len = nullptr;
+		if (t->Struct.soa_kind == StructSoa_Fixed) {
+			len = ir_const_int(t->Struct.soa_count);
+		} else {
+			irValue *v = ir_emit_load(proc, addr.addr);
+			len = ir_soa_struct_len(proc, v);
+		}
 
 		irValue *res = ir_add_local_generated(proc, elem, true);
 
-		if (addr.soa.index->kind != irValue_Constant) {
-			irValue *len = ir_const_int(count);
+		if (addr.soa.index->kind != irValue_Constant || t->Struct.soa_kind != StructSoa_Fixed) {
 			ir_emit_bounds_check(proc, ast_token(addr.soa.index_expr), addr.soa.index, len);
 		}
 
-		for_array(i, t->Struct.fields) {
-			Entity *field = t->Struct.fields[i];
-			Type *base_type = field->type;
-			GB_ASSERT(base_type->kind == Type_Array);
-			Type *elem = base_type->Array.elem;
+		if (t->Struct.soa_kind == StructSoa_Fixed) {
+			for_array(i, t->Struct.fields) {
+				Entity *field = t->Struct.fields[i];
+				Type *base_type = field->type;
+				GB_ASSERT(base_type->kind == Type_Array);
 
+				irValue *dst = ir_emit_struct_ep(proc, res, cast(i32)i);
+				irValue *src_ptr = ir_emit_struct_ep(proc, addr.addr, cast(i32)i);
+				src_ptr = ir_emit_array_ep(proc, src_ptr, addr.soa.index);
+				irValue *src = ir_emit_load(proc, src_ptr);
+				ir_emit_store(proc, dst, src);
+			}
+		} else {
+			isize field_count = t->Struct.fields.count;
+			if (t->Struct.soa_kind == StructSoa_Slice) {
+				field_count -= 1;
+			} else if (t->Struct.soa_kind == StructSoa_Dynamic) {
+				field_count -= 3;
+			}
+			for (isize i = 0; i < field_count; i++) {
+				Entity *field = t->Struct.fields[i];
+				Type *base_type = field->type;
+				GB_ASSERT(base_type->kind == Type_Pointer);
+				Type *elem = base_type->Pointer.elem;
 
-			irValue *dst = ir_emit_struct_ep(proc, res, cast(i32)i);
-			irValue *src_ptr = ir_emit_struct_ep(proc, addr.addr, cast(i32)i);
-			src_ptr = ir_emit_array_ep(proc, src_ptr, addr.soa.index);
-			irValue *src = ir_emit_load(proc, src_ptr);
-			ir_emit_store(proc, dst, src);
+				irValue *dst = ir_emit_struct_ep(proc, res, cast(i32)i);
+				irValue *src_ptr = ir_emit_struct_ep(proc, addr.addr, cast(i32)i);
+				src_ptr = ir_emit_ptr_offset(proc, src_ptr, addr.soa.index);
+				irValue *src = ir_emit_load(proc, src_ptr);
+				src = ir_emit_load(proc, src);
+				ir_emit_store(proc, dst, src);
+			}
 		}
 
 		return ir_emit_load(proc, res);
@@ -3796,6 +3889,7 @@ irValue *ir_map_cap(irProcedure *proc, irValue *value) {
 
 
 
+
 struct irLoopData {
 	irValue *idx_addr;
 	irValue *idx;
@@ -6297,6 +6391,8 @@ irValue *ir_build_builtin_proc(irProcedure *proc, Ast *expr, TypeAndValue tv, Bu
 			return ir_dynamic_array_len(proc, v);
 		} else if (is_type_map(t)) {
 			return ir_map_len(proc, v);
+		} else if (is_type_soa_struct(t)) {
+			return ir_soa_struct_len(proc, v);
 		}
 
 		GB_PANIC("Unreachable");
@@ -6321,6 +6417,8 @@ irValue *ir_build_builtin_proc(irProcedure *proc, Ast *expr, TypeAndValue tv, Bu
 			return ir_dynamic_array_cap(proc, v);
 		} else if (is_type_map(t)) {
 			return ir_map_cap(proc, v);
+		} else if (is_type_soa_struct(t)) {
+			return ir_soa_struct_cap(proc, v);
 		}
 
 		GB_PANIC("Unreachable");
@@ -7557,15 +7655,21 @@ irAddr ir_build_addr(irProcedure *proc, Ast *expr) {
 
 					irValue *arr = ir_emit_struct_ep(proc, addr.addr, first_index);
 
-					if (addr.soa.index->kind != irValue_Constant) {
-						Type *t = base_type(type_deref(ir_type(addr.addr)));
-						GB_ASSERT(t->kind == Type_Struct && t->Struct.soa_kind != StructSoa_None);
-						i64 count = t->Struct.soa_count;
-						irValue *len = ir_const_int(count);
+					Type *t = base_type(type_deref(ir_type(addr.addr)));
+					GB_ASSERT(is_type_soa_struct(t));
+
+					if (addr.soa.index->kind != irValue_Constant || t->Struct.soa_kind != StructSoa_Fixed) {
+						irValue *len = ir_soa_struct_len(proc, addr.addr);
 						ir_emit_bounds_check(proc, ast_token(addr.soa.index_expr), addr.soa.index, len);
 					}
 
-					irValue *item = ir_emit_array_ep(proc, arr, index);
+					irValue *item = nullptr;
+
+					if (t->Struct.soa_kind == StructSoa_Fixed) {
+						item = ir_emit_array_ep(proc, arr, index);
+					} else {
+						item = ir_emit_load(proc, ir_emit_ptr_offset(proc, arr, index));
+					}
 					if (sub_sel.index.count > 0) {
 						item = ir_emit_deep_field_gep(proc, item, sub_sel);
 					}
@@ -7626,10 +7730,8 @@ irAddr ir_build_addr(irProcedure *proc, Ast *expr) {
 
 		bool deref = is_type_pointer(t);
 		t = base_type(type_deref(t));
-		if (t->kind == Type_Struct && t->Struct.soa_kind != StructSoa_None) {
+		if (is_type_soa_struct(t)) {
 			// SOA STRUCTURES!!!!
-			Type *elem = t->Struct.soa_elem;
-
 			irValue *val = ir_build_addr_ptr(proc, ie->expr);
 			if (deref) {
 				val = ir_emit_load(proc, val);
@@ -7639,6 +7741,36 @@ irAddr ir_build_addr(irProcedure *proc, Ast *expr) {
 			return ir_addr_soa_variable(val, index, ie->index);
 		}
 
+		if (ie->expr->tav.mode == Addressing_SoaVariable) {
+			// SOA Structures for slices/dynamic arrays
+			GB_ASSERT(is_type_pointer(type_of_expr(ie->expr)));
+
+			irValue *field = ir_build_expr(proc, ie->expr);
+			irValue *index = ir_build_expr(proc, ie->index);
+
+
+			if (!build_context.no_bounds_check) {
+				// TODO HACK(bill): Clean up this hack to get the length for bounds checking
+				GB_ASSERT(field->kind == irValue_Instr);
+				irInstr *instr = &field->Instr;
+
+				GB_ASSERT(instr->kind == irInstr_Load);
+				irValue *a = instr->Load.address;
+
+				GB_ASSERT(a->kind == irValue_Instr);
+				irInstr *b = &a->Instr;
+				GB_ASSERT(b->kind == irInstr_StructElementPtr);
+				irValue *base_struct = b->StructElementPtr.address;
+
+				GB_ASSERT(is_type_soa_struct(type_deref(ir_type(base_struct))));
+				irValue *len = ir_soa_struct_len(proc, base_struct);
+				ir_emit_bounds_check(proc, ast_token(ie->index), index, len);
+			}
+
+			irValue *val = ir_emit_ptr_offset(proc, field, index);
+			return ir_addr(val);
+		}
+
 		GB_ASSERT_MSG(is_type_indexable(t), "%s %s", type_to_string(t), expr_to_string(expr));
 
 		if (is_type_map(t)) {
@@ -7838,6 +7970,55 @@ irAddr ir_build_addr(irProcedure *proc, Ast *expr) {
 			ir_fill_string(proc, str, elem, new_len);
 			return ir_addr(str);
 		}
+
+
+		case Type_Struct:
+			if (is_type_soa_struct(type)) {
+				irValue *len = ir_soa_struct_len(proc, addr);
+				if (high == nullptr) high = len;
+
+				if (!no_indices) {
+					ir_emit_slice_bounds_check(proc, se->open, low, high, len, se->low != nullptr);
+				}
+
+				irValue *dst = ir_add_local_generated(proc, type_of_expr(expr), true);
+				if (type->Struct.soa_kind == StructSoa_Fixed) {
+					i32 field_count = cast(i32)type->Struct.fields.count;
+					for (i32 i = 0; i < field_count; i++) {
+						irValue *field_dst = ir_emit_struct_ep(proc, dst, i);
+						irValue *field_src = ir_emit_struct_ep(proc, addr, i);
+						field_src = ir_emit_array_ep(proc, field_src, low);
+						ir_emit_store(proc, field_dst, field_src);
+					}
+
+					irValue *len_dst = ir_emit_struct_ep(proc, dst, field_count);
+					irValue *new_len = ir_emit_arith(proc, Token_Sub, high, low, t_int);
+					ir_emit_store(proc, len_dst, new_len);
+				} else if (type->Struct.soa_kind == StructSoa_Slice) {
+					if (no_indices) {
+						ir_emit_store(proc, dst, base);
+					} else {
+						i32 field_count = cast(i32)type->Struct.fields.count - 1;
+						for (i32 i = 0; i < field_count; i++) {
+							irValue *field_dst = ir_emit_struct_ep(proc, dst, i);
+							irValue *field_src = ir_emit_struct_ev(proc, base, i);
+							field_src = ir_emit_ptr_offset(proc, field_src, low);
+							ir_emit_store(proc, field_dst, field_src);
+						}
+
+
+						irValue *len_dst = ir_emit_struct_ep(proc, dst, field_count);
+						irValue *new_len = ir_emit_arith(proc, Token_Sub, high, low, t_int);
+						ir_emit_store(proc, len_dst, new_len);
+					}
+				} else {
+					GB_PANIC("TODO #soa[dynamic]T");
+				}
+
+				return ir_addr(dst);
+			}
+			break;
+
 		}
 
 		GB_PANIC("Unknown slicable type");
diff --git a/src/types.cpp b/src/types.cpp
index 1d89f6e17..63647dcf3 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -811,6 +811,7 @@ Type *alloc_type_simd_vector(i64 count, Type *elem) {
 
 
 
+
 ////////////////////////////////////////////////////////////////
 
 
@@ -1757,7 +1758,10 @@ bool are_types_identical(Type *x, Type *y) {
 			if (x->Struct.is_raw_union == y->Struct.is_raw_union &&
 			    x->Struct.fields.count == y->Struct.fields.count &&
 			    x->Struct.is_packed    == y->Struct.is_packed &&
-			    x->Struct.custom_align == y->Struct.custom_align) {
+			    x->Struct.custom_align == y->Struct.custom_align &&
+			    x->Struct.soa_kind == y->Struct.soa_kind &&
+			    x->Struct.soa_count == y->Struct.soa_count &&
+			    are_types_identical(x->Struct.soa_elem, y->Struct.soa_elem)) {
 				// TODO(bill); Fix the custom alignment rule
 				for_array(i, x->Struct.fields) {
 					Entity *xf = x->Struct.fields[i];