Watch out for PHI instruction with no source operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90488 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index ba9be6a87031d59920e49b3055dbec3df8b2463c..2cafbd418f337fb188b318dfa2f0b9eb1fef535c 100644 (file)
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -1064,6 +1064,8 @@ bool MachineInstr::isInvariantLoad(AliasAnalysis *AA) const {
 unsigned MachineInstr::isConstantValuePHI() const {
   if (getOpcode() != TargetInstrInfo::PHI)
     return 0;
+  if (getNumOperands() <= 1)
+    return 0;
 
   unsigned Reg = getOperand(1).getReg();
   for (unsigned i = 3, e = getNumOperands(); i < e; i += 2)