X86: Make @llvm.frameaddress work correctly with Windows unwind codes
Simply loading or storing the frame pointer is not sufficient for
Windows targets. Instead, create a synthetic frame object that we will
lower later. References to this synthetic object will be replaced with
the correct reference to the frame address.
llvm-svn: 228748
diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index adeb46d..d049c02d 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -1242,6 +1242,9 @@
NumBytes = FrameSize - CSSize;
}
uint64_t SEHFrameOffset = calculateSetFPREG(NumBytes);
+ if (FI && FI == X86FI->getFAIndex())
+ return -SEHFrameOffset;
+
// FPDelta is the offset from the "traditional" FP location of the old base
// pointer followed by return address and the location required by the
// restricted Win64 prologue.