[clang] Fix reading long doubles with va_arg on x86_64 mingw

On x86_64 mingw, long doubles are always passed indirectly as
arguments (see an existing case in WinX86_64ABIInfo::classify);
generalize the existing code for reading varargs - any non-aggregate
type that is larger than 64 bits (which would be both long double
in mingw, and __int128) are passed indirectly too.

This makes reading varargs consistent with how they're passed,
fixing interop with both gcc and clang callers, for long double
and __int128.

Differential Revision: https://reviews.llvm.org/D103452

1 files changed, 2 insertions, 7 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index af516bb..440153c 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -4358,15 +4358,10 @@ void WinX86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
 
 Address WinX86_64ABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                                     QualType Ty) const {
-
-  bool IsIndirect = false;
-
   // MS x64 ABI requirement: "Any argument that doesn't fit in 8 bytes, or is
   // not 1, 2, 4, or 8 bytes, must be passed by reference."
-  if (isAggregateTypeForABI(Ty) || Ty->isMemberPointerType()) {
-    uint64_t Width = getContext().getTypeSize(Ty);
-    IsIndirect = Width > 64 || !llvm::isPowerOf2_64(Width);
-  }
+  uint64_t Width = getContext().getTypeSize(Ty);
+  bool IsIndirect = Width > 64 || !llvm::isPowerOf2_64(Width);
 
   return emitVoidPtrVAArg(CGF, VAListAddr, Ty, IsIndirect,
                           CGF.getContext().getTypeInfoInChars(Ty),