Proper fix for PR1037: to determine is a VR is a modref, check 1) whether it is

tied to another oeprand, 2) whether is is being tied to by another operand. So
the destination operand of a two-address MI can be correctly identified.

llvm-svn: 32354

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/VirtRegMap.cpp b/llvm/lib/CodeGen/VirtRegMap.cpp
index 8184075113d..83543dc29da 100644
--- a/llvm/lib/CodeGen/VirtRegMap.cpp
+++ b/llvm/lib/CodeGen/VirtRegMap.cpp
@@ -97,7 +97,9 @@ void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI,
   }
 
   ModRef MRInfo;
-  if (TII.getOperandConstraint(OldMI->getOpcode(), OpNo, TOI::TIED_TO)) {
+  const TargetInstrDescriptor *TID = OldMI->getInstrDescriptor();
+  if (TID->getOperandConstraint(OpNo, TOI::TIED_TO) != -1 ||
+      TII.findTiedToSrcOperand(TID, OpNo) != -1) {
     // Folded a two-address operand.
     MRInfo = isModRef;
   } else if (OldMI->getOperand(OpNo).isDef()) {
@@ -849,7 +851,7 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
         // If this def is part of a two-address operand, make sure to execute
         // the store from the correct physical register.
         unsigned PhysReg;
-        int TiedOp = TII->findTiedToSrcOperand(MI.getOpcode(), i);
+        int TiedOp = TII->findTiedToSrcOperand(MI.getInstrDescriptor(), i);
         if (TiedOp != -1)
           PhysReg = MI.getOperand(TiedOp).getReg();
         else {