[PATCH] D31164: [IR] Add AllowContract to FastMathFlags
Adam Nemet via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 20 20:51:24 PDT 2017
anemet added inline comments.
Comment at: docs/LangRef.rst:2199
+ Allow floating-point contraction (e.g. fusing a multiply followed by an
+ addition into a fused multiply-and-add).
> Is it the intent to allow this as well : x + x + x -> 3 * x ?
I don't think so. We do the general case (any number of terms) under unsafe-math, in FAddCombine::simplify in InstCombine.
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