[PATCH] D109525: [SVE] Remove isel patterns for (fneg (fma)) -> fnmla.

Dave Green via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Thu Sep 9 12:49:11 PDT 2021


dmgreen added inline comments.


================
Comment at: llvm/test/CodeGen/AArch64/sve-fp-combine.ll:407-409
   %neg_m1 = fneg fast <vscale x 8 x half> %m1
   %mul = fmul fast <vscale x 8 x half> %neg_m1, %m2
   %res = fsub fast <vscale x 8 x half> %mul, %acc
----------------
craig.topper wrote:
> dmgreen wrote:
> > These are all fast...?
> That's true, but the patterns weren't checking that. Would you prefer I add a PatFrag to check the fast math flags and keep the patterns?
It would seem prudent to not delete obviously useful patterns. Having non-fast tests would be useful too, if we don't have them already.

Same goes for D109523 but the tests might be reversed there, where we have non-fast tests, but no nsz tests.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109525/new/

https://reviews.llvm.org/D109525



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