https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95060
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I see the needed simplifiers in match.pd:
(simplify
(negate (fmas@3 @0 @1 @2))
(if (single_use (@3))
(IFN_FNMS @0 @1 @2))))
but perhaps the problem is that there is no forwprop after widening_mul that
would perform that optimization?
So, shall widening_mul itself if it matches some FMA check if the result of
IFN_{FMA,FMS,FNMA,FNMS} it created isn't negation and if yes, try to
gimple_fold it?
