Properly handle passing of FP stuff to varargs function on Win64:
value should be copied to the corresponding shadow reg as well.
Patch by Cameron Esfahani!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112262 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 8927afe..cddf5c6 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2008,6 +2008,19 @@
if (VA.isRegLoc()) {
RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
+ if (isVarArg && Subtarget->isTargetWin64()) {
+ // Win64 ABI requires argument XMM reg to be copied to the corresponding
+ // shadow reg if callee is a varargs function.
+ unsigned ShadowReg = 0;
+ switch (VA.getLocReg()) {
+ case X86::XMM0: ShadowReg = X86::RCX; break;
+ case X86::XMM1: ShadowReg = X86::RDX; break;
+ case X86::XMM2: ShadowReg = X86::R8; break;
+ case X86::XMM3: ShadowReg = X86::R9; break;
+ }
+ if (ShadowReg)
+ RegsToPass.push_back(std::make_pair(ShadowReg, Arg));
+ }
} else if (!IsSibcall && (!isTailCall || isByVal)) {
assert(VA.isMemLoc());
if (StackPtr.getNode() == 0)