[PATCH] D72824: [X86] Add combination for fma and fneg on X86 under strict FP.

Thu Jan 23 02:00:34 PST 2020

RKSimon added a comment.

In D72824#1835633 <https://reviews.llvm.org/D72824#1835633>, @pengfei wrote:

> In D72824#1835568 <https://reviews.llvm.org/D72824#1835568>, @RKSimon wrote:
>
> > Add to isNegatibleForFree/getNegatedExpression as well?
>
>
> We don't need to add them to isNegatibleForFree/getNegatedExpression. We won't negate any FMA results by negative FMA instructions under strict FP, because fneg(FMA) has different result from FNMA under some rounding mode.

Thanks for confirming - no more comments from me.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D72824/new/

https://reviews.llvm.org/D72824