[PATCH] D107285: [FPEnv][InstSimplify] Enable more folds for constrained fsub

[Serge Pavlov via Phabricator via llvm-commits]

sepavloff added inline comments.


================
Comment at: llvm/lib/Analysis/InstructionSimplify.cpp:4963
   // fsub X, +0 ==> X
-  if (match(Op1, m_PosZeroFP()))
-    return Op0;
+  if (ExBehavior != fp::ebStrict || FMF.noNaNs())
+    if (match(Op1, m_PosZeroFP()))
----------------
This transformation is valid only if `FMF.noNaNs()` is set, because it is incorrect if `X==SNaN`. Similar for other cases below.



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  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D107285/new/

https://reviews.llvm.org/D107285