X86FrameLowering: Fix getFrameIndexReference() for 'fixed' objects

Debug information is calculated with getFrameIndexReference() which was
missing some logic for the fixed object cases (= parameters on the stack).

rdar://24557797

Differential Revision: https://reviews.llvm.org/D32204

llvm-svn: 300781

1 files changed, 3 insertions, 6 deletions

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index 78e0bca4158..8678a13b95d 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -1698,21 +1698,18 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   }
 }
 
-// NOTE: this only has a subset of the full frame index logic. In
-// particular, the FI < 0 and AfterFPPop logic is handled in
-// X86RegisterInfo::eliminateFrameIndex, but not here. Possibly
-// (probably?) it should be moved into here.
 int X86FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
                                              unsigned &FrameReg) const {
   const MachineFrameInfo &MFI = MF.getFrameInfo();
 
+  bool IsFixed = MFI.isFixedObjectIndex(FI);
   // We can't calculate offset from frame pointer if the stack is realigned,
   // so enforce usage of stack/base pointer.  The base pointer is used when we
   // have dynamic allocas in addition to dynamic realignment.
   if (TRI->hasBasePointer(MF))
-    FrameReg = TRI->getBaseRegister();
+    FrameReg = IsFixed ? TRI->getFramePtr() : TRI->getBaseRegister();
   else if (TRI->needsStackRealignment(MF))
-    FrameReg = TRI->getStackRegister();
+    FrameReg = IsFixed ? TRI->getFramePtr() : TRI->getStackRegister();
   else
     FrameReg = TRI->getFrameRegister(MF);