[llvm] r175732 - Don't rely on the isDead() MachineOperand flag when updating LiveIntervals.

[Cameron Zwarich]

Author: zwarich
Date: Thu Feb 21 02:51:58 2013
New Revision: 175732

URL: http://llvm.org/viewvc/llvm-project?rev=175732&view=rev
Log:
Don't rely on the isDead() MachineOperand flag when updating LiveIntervals.

Modified:
    llvm/trunk/lib/CodeGen/PHIElimination.cpp

Modified: llvm/trunk/lib/CodeGen/PHIElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PHIElimination.cpp?rev=175732&r1=175731&r2=175732&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/PHIElimination.cpp Thu Feb 21 02:51:58 2013
@@ -320,7 +320,9 @@ void PHIElimination::LowerPHINode(Machin
     }
 
     LiveInterval &DestLI = LIS->getInterval(DestReg);
-    if (NewInstr->getOperand(0).isDead()) {
+    assert(DestLI.begin() != DestLI.end() &&
+           "PHIs should have nonempty LiveIntervals.");
+    if (DestLI.endIndex().isDead()) {
       // A dead PHI's live range begins and ends at the start of the MBB, but
       // the lowered copy, which will still be dead, needs to begin and end at
       // the copy instruction.