[clang] [X86_64] fix SSE type error in vaarg. (PR #86377)

[Eli Friedman via cfe-commits]

================
@@ -0,0 +1,69 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 4
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s
+
+
+typedef struct { struct {} a; } empty;
+
+// CHECK-LABEL: define dso_local void @empty_record_test(
+// CHECK-SAME: i32 noundef [[Z:%.*]], ...) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[RETVAL:%.*]] = alloca [[STRUCT_EMPTY:%.*]], align 1
+// CHECK-NEXT:    [[Z_ADDR:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[LIST:%.*]] = alloca [1 x %struct.__va_list_tag], align 16
+// CHECK-NEXT:    [[TMP:%.*]] = alloca [[STRUCT_EMPTY]], align 1
+// CHECK-NEXT:    store i32 [[Z]], ptr [[Z_ADDR]], align 4
+// CHECK-NEXT:    [[ARRAYDECAY:%.*]] = getelementptr inbounds [1 x %struct.__va_list_tag], ptr [[LIST]], i64 0, i64 0
+// CHECK-NEXT:    call void @llvm.va_start(ptr [[ARRAYDECAY]])
+// CHECK-NEXT:    [[ARRAYDECAY1:%.*]] = getelementptr inbounds [1 x %struct.__va_list_tag], ptr [[LIST]], i64 0, i64 0
+// CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr align 1 [[RETVAL]], ptr align 1 [[TMP]], i64 0, i1 false)
+// CHECK-NEXT:    ret void
+//
+empty empty_record_test(int z, ...) {
+  __builtin_va_list list;
+  __builtin_va_start(list, z);
+  return __builtin_va_arg(list, empty);
+}
+
+typedef struct {
+  struct{} a;
+  double b;
+} s1;
----------------
efriedma-quic wrote:

Not sure this is really worth testing... at least, it's not testing anything relevant to this patch.  (sizeof(s1)==8.)  Up to you, I guess.

https://github.com/llvm/llvm-project/pull/86377