Fix #1319

src/llvm_backend_expr.cpp

@@ -1841,7 +1841,6 @@ lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t) {
 		return res;
 	}
 
-	#if 1
 	if (is_type_union(dst)) {
 		for_array(i, dst->Union.variants) {
 			Type *vt = dst->Union.variants[i];
@@ -1852,7 +1851,6 @@ lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t) {
 			}
 		}
 	}
-	#endif
 
 	// NOTE(bill): This has to be done before 'Pointer <-> Pointer' as it's
 	// subtype polymorphism casting

src/llvm_backend_general.cpp

@@ -1142,7 +1142,7 @@ lbValue lb_emit_union_tag_ptr(lbProcedure *p, lbValue u) {
 
 	LLVMTypeRef uvt = LLVMGetElementType(LLVMTypeOf(u.value));
 	unsigned element_count = LLVMCountStructElementTypes(uvt);
-	GB_ASSERT_MSG(element_count == 2, "element_count=%u (%s) != (%s)", element_count, type_to_string(ut), LLVMPrintTypeToString(uvt));
+	GB_ASSERT_MSG(element_count >= 2, "element_count=%u (%s) != (%s)", element_count, type_to_string(ut), LLVMPrintTypeToString(uvt));
 
 	lbValue tag_ptr = {};
 	tag_ptr.value = LLVMBuildStructGEP(p->builder, u.value, 1, "");
@@ -1795,7 +1795,7 @@ LLVMTypeRef lb_type_internal(lbModule *m, Type *type) {
 
 			unsigned block_size = cast(unsigned)type->Union.variant_block_size;
 
-			auto fields = array_make<LLVMTypeRef>(temporary_allocator(), 0, 2);
+			auto fields = array_make<LLVMTypeRef>(temporary_allocator(), 0, 3);
 			if (is_type_union_maybe_pointer(type)) {
 				LLVMTypeRef variant = lb_type(m, type->Union.variants[0]);
 				array_add(&fields, variant);
@@ -1804,7 +1804,12 @@ LLVMTypeRef lb_type_internal(lbModule *m, Type *type) {
 				LLVMTypeRef tag_type   = lb_type(m, union_tag_type(type));
 				array_add(&fields, block_type);
 				array_add(&fields, tag_type);
-				
+				i64 used_size = lb_sizeof(block_type) + lb_sizeof(tag_type);
+				i64 padding = size - used_size;
+				if (padding > 0) {
+					LLVMTypeRef padding_type = lb_type_padding_filler(m, padding, align);
+					array_add(&fields, padding_type);
+				}
 			}
 			
 			return LLVMStructTypeInContext(ctx, fields.data, cast(unsigned)fields.count, false);

src/llvm_backend_stmt.cpp

@@ -1485,7 +1485,14 @@ void lb_build_return_stmt_internal(lbProcedure *p, lbValue const &res) {
 
 	if (return_by_pointer) {
 		if (res.value != nullptr) {
-			LLVMBuildStore(p->builder, res.value, p->return_ptr.addr.value);
+			LLVMValueRef res_val = res.value;
+			i64 sz = type_size_of(res.type);
+			if (LLVMIsALoadInst(res_val) && sz > build_context.word_size) {
+				lbValue ptr = lb_address_from_load_or_generate_local(p, res);
+				lb_mem_copy_non_overlapping(p, p->return_ptr.addr, ptr, lb_const_int(p->module, t_int, sz));
+			} else {
+				LLVMBuildStore(p->builder, res_val, p->return_ptr.addr.value);
+			}
 		} else {
 			LLVMBuildStore(p->builder, LLVMConstNull(p->abi_function_type->ret.type), p->return_ptr.addr.value);
 		}

src/types.cpp

@@ -4019,7 +4019,13 @@ gbString write_type_to_string(gbString str, Type *type) {
 
 	case Type_BitSet:
 		str = gb_string_appendc(str, "bit_set[");
-		str = write_type_to_string(str, type->BitSet.elem);
+		if (is_type_enum(type->BitSet.elem)) {
+			str = write_type_to_string(str, type->BitSet.elem);
+		} else {
+			str = gb_string_append_fmt(str, "%lld", type->BitSet.lower);
+			str = gb_string_append_fmt(str, "..=");
+			str = gb_string_append_fmt(str, "%lld", type->BitSet.upper);
+		}
 		if (type->BitSet.underlying != nullptr) {
 			str = gb_string_appendc(str, "; ");
 			str = write_type_to_string(str, type->BitSet.underlying);