[LiveRangeEdit] Add assert string and descriptive comment.
llvm-svn: 289456
diff --git a/llvm/lib/CodeGen/LiveRangeEdit.cpp b/llvm/lib/CodeGen/LiveRangeEdit.cpp
index 88fed62..918be47 100644
--- a/llvm/lib/CodeGen/LiveRangeEdit.cpp
+++ b/llvm/lib/CodeGen/LiveRangeEdit.cpp
@@ -273,7 +273,9 @@
bool isOrigDef = false;
unsigned Dest;
if (VRM && MI->getOperand(0).isReg() && MI->getOperand(0).isDef()) {
- assert(MI->getDesc().getNumDefs() == 1);
+ // It is assumed that callers of eliminateDeadDefs() will never pass in dead
+ // instructions with multiple virtual register defs.
+ assert(MI->getDesc().getNumDefs() == 1 && "Unexpected instruction with multiple defs.");
Dest = MI->getOperand(0).getReg();
unsigned Original = VRM->getOriginal(Dest);
LiveInterval &OrigLI = LIS.getInterval(Original);