PEI: Skip dead objects when looking at CSRs

On AMDGPU if an SGPR is spilled to a VGPR, the frame index
is deleted. If there were any CSR SGPRs, this woudl
assert when setting the offset.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301961 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index 570a0cd0ba90153a216228532353e54783b48c8b..549f07ecd9ce9852faf50999c54d4ca555e486e3 100644 (file)
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -761,6 +761,9 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
   } else if (MaxCSFrameIndex >= MinCSFrameIndex) {
     // Be careful about underflow in comparisons agains MinCSFrameIndex.
     for (unsigned i = MaxCSFrameIndex; i != MinCSFrameIndex - 1; --i) {
+      if (MFI.isDeadObjectIndex(i))
+        continue;
+
       unsigned Align = MFI.getObjectAlignment(i);
       // Adjust to alignment boundary
       Offset = alignTo(Offset, Align, Skew);