i386 ABI: Offset computation in va_arg was incorrect for sizeof(Ty)>4.

We are down to only failing gcc.dg/compat/vector-[12] (8 tests total).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64967 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index f012d93..45b386f 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -360,14 +360,11 @@
     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
   
-  uint64_t SizeInBytes = CGF.getContext().getTypeSize(Ty) / 8;
-  const unsigned ArgumentSizeInBytes = 4;
-  if (SizeInBytes < ArgumentSizeInBytes)
-    SizeInBytes = ArgumentSizeInBytes;
-
+  uint64_t Offset = 
+    llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
   llvm::Value *NextAddr = 
     Builder.CreateGEP(Addr, 
-                      llvm::ConstantInt::get(llvm::Type::Int32Ty, SizeInBytes),
+                      llvm::ConstantInt::get(llvm::Type::Int32Ty, Offset),
                       "ap.next");
   Builder.CreateStore(NextAddr, VAListAddrAsBPP);