Now that RegistersDefinedFromSameValue handles one instruction being an

implicit_def, the other instruction can be anything, including instructions
that define multiple values. Be careful about that and don't assume what operand
0 is.
Fixes pr13249.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159509 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 14 deletions

diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index 6ef098d1a1..733312fbd0 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -1175,28 +1175,18 @@ static bool RegistersDefinedFromSameValue(LiveIntervals &li,
   if (!MI || CP.isPartial() || CP.isPhys())
     return false;
 
-  unsigned Dst = MI->getOperand(0).getReg();
-  if (!TargetRegisterInfo::isVirtualRegister(Dst))
+  unsigned A = CP.getDstReg();
+  if (!TargetRegisterInfo::isVirtualRegister(A))
     return false;
 
-  unsigned A = CP.getDstReg();
   unsigned B = CP.getSrcReg();
-
-  if (B == Dst)
-    std::swap(A, B);
-  assert(Dst == A);
+  if (!TargetRegisterInfo::isVirtualRegister(B))
+    return false;
 
   MachineInstr *OtherMI = li.getInstructionFromIndex(OtherVNI->def);
-
   if (!OtherMI)
     return false;
 
-  unsigned OtherDst = OtherMI->getOperand(0).getReg();
-  if (!TargetRegisterInfo::isVirtualRegister(OtherDst))
-    return false;
-
-  assert(OtherDst == B);
-
   if (MI->isImplicitDef()) {
     DupCopies.push_back(MI);
     return true;