[llvm] [InstCombine] Infer exact for lshr by cttz (PR #136696)

[Nikita Popov via llvm-commits]

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@@ -994,6 +994,18 @@ static bool setShiftFlags(BinaryOperator &I, const SimplifyQuery &Q) {
       I.setIsExact();
       return true;
     }
+    //Fix #131444
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nikic wrote:

Don't reference the issue, instead add a compact comment on what the transform does. Like `// Infer exact on shift by cttz`.

https://github.com/llvm/llvm-project/pull/136696