1 files changed, 12 insertions, 0 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index e54d365fdae..19061c5fc09 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -32,6 +32,7 @@
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/GlobalValue.h"
+#include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCInstrDesc.h"
 #include "llvm/Support/Casting.h"
@@ -1928,6 +1929,17 @@ bool AArch64InstrInfo::isCandidateToMergeOrPair(const MachineInstr &MI) const {
   if (isLdStPairSuppressed(MI))
     return false;
 
+  // Do not pair any callee-save store/reload instructions in the
+  // prologue/epilogue if the CFI information encoded the operations as separate
+  // instructions, as that will cause the size of the actual prologue to mismatch
+  // with the prologue size recorded in the Windows CFI.
+  const MCAsmInfo *MAI = MI.getMF()->getTarget().getMCAsmInfo();
+  bool NeedsWinCFI = MAI->usesWindowsCFI() &&
+                     MI.getMF()->getFunction().needsUnwindTableEntry();
+  if (NeedsWinCFI && (MI.getFlag(MachineInstr::FrameSetup) ||
+                      MI.getFlag(MachineInstr::FrameDestroy)))
+    return false;
+
   // On some CPUs quad load/store pairs are slower than two single load/stores.
   if (Subtarget.isPaired128Slow()) {
     switch (MI.getOpcode()) {