[llvm] [InstCombine] Fold select of ordered fcmps of fabs over `isKnownNeverNaN`-selects to a single select (PR #192182)

via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 14 22:12:34 PDT 2026


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git-clang-format --diff origin/main HEAD --extensions cpp -- llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp --diff_from_common_commit
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``````````diff
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 21556d8aa..1d90697f1 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -3439,11 +3439,10 @@ foldSelectOfOrderedFAbsCmpOfNaNScrubbedValue(SelectInst &SI,
   }
 
   Value *NewAbs = IC.Builder.CreateUnaryIntrinsic(Intrinsic::fabs, X);
-  Value *NewCmp = Swapped
-                      ? IC.Builder.CreateFCmpFMF(OuterCmp->getPredicate(),
-                                                 OtherOp, NewAbs, OuterCmp)
-                      : IC.Builder.CreateFCmpFMF(OuterCmp->getPredicate(),
-                                                 NewAbs, OtherOp, OuterCmp);
+  Value *NewCmp = Swapped ? IC.Builder.CreateFCmpFMF(OuterCmp->getPredicate(),
+                                                     OtherOp, NewAbs, OuterCmp)
+                          : IC.Builder.CreateFCmpFMF(OuterCmp->getPredicate(),
+                                                     NewAbs, OtherOp, OuterCmp);
   Value *NewSel = IC.Builder.CreateSelectFMF(NewCmp, X, Y, &SI);
   return IC.replaceInstUsesWith(SI, NewSel);
 }

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https://github.com/llvm/llvm-project/pull/192182


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