[llvm] [InstCombine] Infer zext nneg flag directly (PR #71906)

[Nikita Popov via llvm-commits]

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@@ -639,7 +641,9 @@ static Instruction *foldCtpop(IntrinsicInst &II, InstCombinerImpl &IC) {
   // ctpop (zext X) --> zext (ctpop X)
   if (match(Op0, m_OneUse(m_ZExt(m_Value(X))))) {
     Value *NarrowPop = IC.Builder.CreateUnaryIntrinsic(Intrinsic::ctpop, X);
-    return CastInst::Create(Instruction::ZExt, NarrowPop, Ty);
+    Instruction *Zext = CastInst::Create(Instruction::ZExt, NarrowPop, Ty);
+    Zext->setNonNeg();
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nikic wrote:

Is this correct for i1?

https://github.com/llvm/llvm-project/pull/71906