Don't consider instructions with implicit physical register

defs to be necessarily live.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56310 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/DeadMachineInstructionElim.cpp b/lib/CodeGen/DeadMachineInstructionElim.cpp
index a3bba61e4a2307a15a19a09e1e744b3e6a2d3b72..8b9cf05d675223a346bfa19eaf3bcadadbc4ab46 100644 (file)
--- a/lib/CodeGen/DeadMachineInstructionElim.cpp
+++ b/lib/CodeGen/DeadMachineInstructionElim.cpp
@@ -64,7 +64,8 @@ bool DeadMachineInstructionElim::runOnMachineFunction(MachineFunction &MF) {
           const MachineOperand &MO = MI->getOperand(i);
           if (MO.isRegister() && MO.isDef()) {
             unsigned Reg = MO.getReg();
-            if (TargetRegisterInfo::isPhysicalRegister(Reg) ||
+            if ((!MO.isImplicit() &&
+                 TargetRegisterInfo::isPhysicalRegister(Reg)) ||
                 !MRI.use_empty(Reg)) {
               // This def has a use. Don't delete the instruction!
               AllDefsDead = false;