AMDGPU: Fix a corner case crash in SIOptimizeExecMasking
Summary:
See the new test case; this is really unlikely to happen with real code,
but I ran into this while attempting to bugpoint-reduce a different issue.
Change-Id: I9ade1dc1aa8fd9c4d9fc83661d7b80e310b5c4a6
Reviewers: arsenm, rampitec
Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D45885
llvm-svn: 330585
diff --git a/llvm/lib/Target/AMDGPU/SIOptimizeExecMasking.cpp b/llvm/lib/Target/AMDGPU/SIOptimizeExecMasking.cpp
index 2dc6f27..ddf45bb 100644
--- a/llvm/lib/Target/AMDGPU/SIOptimizeExecMasking.cpp
+++ b/llvm/lib/Target/AMDGPU/SIOptimizeExecMasking.cpp
@@ -76,7 +76,7 @@
case AMDGPU::COPY:
case AMDGPU::S_MOV_B64: {
const MachineOperand &Dst = MI.getOperand(0);
- if (Dst.isReg() && Dst.getReg() == AMDGPU::EXEC)
+ if (Dst.isReg() && Dst.getReg() == AMDGPU::EXEC && MI.getOperand(1).isReg())
return MI.getOperand(1).getReg();
break;
}