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)
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 91c45c2..5280940 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -1845,6 +1845,33 @@
return X86::GR8_ABCD_HRegClass.contains(Reg);
}
+// Try and copy between VR128/VR64 and GR64 registers.
+static unsigned CopyToFromAsymmetricReg(unsigned DestReg, unsigned SrcReg) {
+ // SrcReg(VR128) -> DestReg(GR64)
+ // SrcReg(VR64) -> DestReg(GR64)
+ // SrcReg(GR64) -> DestReg(VR128)
+ // SrcReg(GR64) -> DestReg(VR64)
+
+ if (X86::GR64RegClass.contains(DestReg)) {
+ if (X86::VR128RegClass.contains(SrcReg)) {
+ // Copy from a VR128 register to a GR64 register.
+ return X86::MOVPQIto64rr;
+ } else if (X86::VR64RegClass.contains(SrcReg)) {
+ // Copy from a VR64 register to a GR64 register.
+ return X86::MOVSDto64rr;
+ }
+ } else if (X86::GR64RegClass.contains(SrcReg)) {
+ // Copy from a GR64 register to a VR128 register.
+ if (X86::VR128RegClass.contains(DestReg))
+ return X86::MOV64toPQIrr;
+ // Copy from a GR64 register to a VR64 register.
+ else if (X86::VR64RegClass.contains(DestReg))
+ return X86::MOV64toSDrr;
+ }
+
+ return 0;
+}
+
void X86InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
@@ -1869,6 +1896,8 @@
Opc = X86::MOVAPSrr;
else if (X86::VR64RegClass.contains(DestReg, SrcReg))
Opc = X86::MMX_MOVQ64rr;
+ else
+ Opc = CopyToFromAsymmetricReg(DestReg, SrcReg);
if (Opc) {
BuildMI(MBB, MI, DL, get(Opc), DestReg)