[PATCH] D23134: Make cltz and cttz zero undef when the operand cannot be zero in InstCombine

[Sanjay Patel via llvm-commits]

spatel added inline comments.

================
Comment at: lib/Transforms/InstCombine/InstCombineCalls.cpp:1141
@@ +1140,3 @@
+    if (!match(II.getArgOperand(1), m_One())) {
+      IC.Worklist.Add(&II);
+      II.setOperand(1, IC.Builder->getTrue());
----------------
Shouldn't this return the updated instruction to signal to the callers that a change was made? If we do that, then we don't need to explicitly add to the worklist either, right?


https://reviews.llvm.org/D23134