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From: "chenglulu at loongson dot cn" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/114978] [14/15 regression] 548.exchange2_r 14%-28%
 regressions on Loongarch64 after gcc 14 snapshot 20240317
Date: Tue, 21 May 2024 13:04:17 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114978

--- Comment #22 from chenglulu <chenglulu at loongson dot cn> ---
(In reply to Xi Ruoyao from comment #21)
> (In reply to chenglulu from comment #19)
> > diff --git a/gcc/config/loongarch/loongarch.cc
> > b/gcc/config/loongarch/loongarch.cc
> > index e7835ae34ae..6a808cb0a5c 100644
> > --- a/gcc/config/loongarch/loongarch.cc
> > +++ b/gcc/config/loongarch/loongarch.cc
> > @@ -2383,7 +2383,7 @@ loongarch_address_insns (rtx x, machine_mode mode,
> > bool might_split_p)
> >         return factor;
> >=20=20
> >        case ADDRESS_REG_REG:
> > -       return factor;
> > +       return factor * 3;
> >=20=20
> >        case ADDRESS_CONST_INT:
> >         return lsx_p ? 0 : factor;
> >=20
> > With this patch, -march=3Dla464 has a score of 11.9.
> > However, the specific revision plan has not yet been decided.
>=20
> Hmm are ldx and stx really so slow?

I think it's more like it's because LDX/STX uses an extra register.=