Target/X86: Tweak va_arg for Win64 not to miss taking va_start when number of fixed args > 4.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127328 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 2eb9841..9ce0046 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1744,8 +1744,8 @@
// If the function takes variable number of arguments, make a frame index for
// the start of the first vararg value... for expansion of llvm.va_start.
if (isVarArg) {
- if (!IsWin64 && (Is64Bit || (CallConv != CallingConv::X86_FastCall &&
- CallConv != CallingConv::X86_ThisCall))) {
+ if (Is64Bit || (CallConv != CallingConv::X86_FastCall &&
+ CallConv != CallingConv::X86_ThisCall)) {
FuncInfo->setVarArgsFrameIndex(MFI->CreateFixedObject(1, StackSize,true));
}
if (Is64Bit) {
@@ -1797,7 +1797,9 @@
int HomeOffset = TFI.getOffsetOfLocalArea() + 8;
FuncInfo->setRegSaveFrameIndex(
MFI->CreateFixedObject(1, NumIntRegs * 8 + HomeOffset, false));
- FuncInfo->setVarArgsFrameIndex(FuncInfo->getRegSaveFrameIndex());
+ // Fixup to set vararg frame on shadow area (4 x i64).
+ if (NumIntRegs < 4)
+ FuncInfo->setVarArgsFrameIndex(FuncInfo->getRegSaveFrameIndex());
} else {
// For X86-64, if there are vararg parameters that are passed via
// registers, then we must store them to their spots on the stack so they