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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug target/102473] [12 Regression] 521.wrf_r 5% slower at -Ofast
 and generic x86_64 tuning after r12-3426-g8f323c712ea76c
Date: Tue, 28 Sep 2021 02:59:17 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102473

--- Comment #15 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to H.J. Lu from comment #14)
> (In reply to Hongtao.liu from comment #13)
> > (In reply to H.J. Lu from comment #12)
> > > Are glibc regressions real? Please show the affected glibc assembly c=
odes
> > > before and after.
> >=20
> > Assembly codes is the same, but DSB coverage drop down. before my commi=
t=20
> > front-end bound of libc-2.31.so is 1.2%, after my commit front-end bound
> > raise up to 21.9%, use -falign-functions=3D64 doesn't help.
> >=20
> > The below code is copy from one of libc functions which has big front-e=
nd
> > bounds
> >=20
>=20
> Which functions in glibc get lower DSB coverage?

About a dozen small functions have been affected,  no symbol info, the seco=
nd
column is time(seconds)


 func@0x5eed4   1.77755
 func@0x58de4   1.53788
 func@0x76f20   0.963671
 func@0x5ea50   0.758953
 func@0x83750   0.349518
 func@0x60d59   0.284607
 func@0x799e4   0.164773
 func@0x59b64   0.15978
 func@0x8f070   0.1448=