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From: "rsandifo at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/97127] FMA3 code transformation leads to slowdown on
 Skylake
Date: Wed, 30 Sep 2020 12:09:20 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97127

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu.org

--- Comment #18 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.o=
rg> ---
Not sure this is a good idea or not, but: combine could
look at the constraints of the instruction it matches,
compare that with the information it has about whether
the inputs remain live after the instruction, and cost
in an extra move if all alternatives require a reload.=