Fix buildbot breakage where a def is missing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107698 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 0a1885f329d84ce9b6f4b3d9dcc2b39bb3be57ad..c450136001c405a2d2e96f9273446176ad27b186 100644 (file)
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -352,6 +352,8 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(const CoalescerPair &CP,
       AValNo->isUnused() || AValNo->hasPHIKill())
     return false;
   MachineInstr *DefMI = li_->getInstructionFromIndex(AValNo->def);
+  if (!DefMI)
+    return false;
   const TargetInstrDesc &TID = DefMI->getDesc();
   if (!TID.isCommutable())
     return false;