[ms-cxxabi] Use inalloca on win32 when passing non-trivial C++ objects

When a non-trivial parameter is present, clang now gathers up all the
parameters that lack inreg and puts them into a packed struct.  MSVC
always aligns each parameter to 4 bytes and no more, so this is a pretty
simple struct to lay out.

On win64, non-trivial records are passed indirectly.  Prior to this
change, clang was incorrectly using byval on win64.

I'm able to self-host a working clang with this change and additional
LLVM patches.

Reviewers: rsmith

Differential Revision: http://llvm-reviews.chandlerc.com/D2636

llvm-svn: 200597

1 files changed, 1 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index 273fed52d5c..4c48afe0752 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -1714,9 +1714,8 @@ CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D,
 
   // Emit the call.
   llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(D, Type);
-  RequiredArgs Required = RequiredArgs::forPrototypePlus(FPT, 1 + ExtraArgs);
   const CGFunctionInfo &Info =
-      CGM.getTypes().arrangeCXXMethodCall(Args, FPT, Required);
+      CGM.getTypes().arrangeCXXConstructorCall(Args, D, Type, ExtraArgs);
   EmitCall(Info, Callee, ReturnValueSlot(), Args, D);
 }