Unify semantics of the built-in `swizzle` procedure with the selector expression semantics e.g. `.xyz`

1 files changed, 22 insertions, 3 deletions

diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index ea89ec007..c0ba40503 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -778,12 +778,31 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		if (arg_count < max_count) {
 			operand->type = alloc_type_array(elem_type, arg_count);
 		}
-		operand->mode = Addressing_Value;
+		if (type->kind == Type_Array) {
+			if (operand->mode == Addressing_Variable) {
+				operand->mode = Addressing_SwizzleVariable;
+			} else {
+				operand->mode = Addressing_SwizzleValue;
+			}
+		} else {
+			operand->mode = Addressing_Value;
+		}
 
-		if (type_hint != nullptr && check_is_castable_to(c, operand, type_hint)) {
-			operand->type = type_hint;
+		Type *array_type = base_type(type_deref(operand->type));
+		GB_ASSERT(array_type->kind == Type_Array);
+
+		Type *swizzle_array_type = nullptr;
+		Type *bth = base_type(type_hint);
+		if (bth != nullptr && bth->kind == Type_Array &&
+		    bth->Array.count == arg_count &&
+		    are_types_identical(bth->Array.elem, array_type->Array.elem)) {
+			swizzle_array_type = type_hint;
+		} else {
+			swizzle_array_type = alloc_type_array(array_type->Array.elem, arg_count);
 		}
 
+		operand->type = swizzle_array_type;
+
 		break;
 	}