From: Florian Weimer <fw@deneb.enyo.de>
To: Noah Goldstein <goldstein.w.n@gmail.com>
Cc: "H.J. Lu" <hjl.tools@gmail.com>,
"H.J. Lu via Libc-alpha" <libc-alpha@sourceware.org>,
GCC Development <gcc@gcc.gnu.org>,
Arjan van de Ven <arjan@linux.intel.com>
Subject: Re: [PATCH] x86-64: Optimize memset for zeroing
Date: Fri, 31 Dec 2021 23:05:14 +0100 [thread overview]
Message-ID: <874k6ofn1h.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <CAFUsyfJ4KgiFjP1Fpt_Dg2spkDiiwcO7+98yS0Gms9oxRmS05w@mail.gmail.com> (Noah Goldstein's message of "Fri, 31 Dec 2021 15:15:57 -0600")
* Noah Goldstein:
>> >> bzero does not have the interface ambiguity that bcmp has. So the
>> >> only reason for not using it would be namespace cleanliness.
>> >
>> > bzero isn't a standard C function and it isn't optimized like memset
>> > in glibc.
>
> It could be an issue if the "optimization" was made and then the
> binary was run with an older version of GCC that was still using
> the aliasing bzero. Would end up being a deoptimization then.
That's a fair point.
next prev parent reply other threads:[~2021-12-31 22:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20211231182010.107040-1-hjl.tools@gmail.com>
[not found] ` <CAFUsyfJ5wHJHkfcL84j+GLCX-Dba4qVt_RuCpu=aLy7-_YbHLA@mail.gmail.com>
2021-12-31 20:35 ` H.J. Lu
2021-12-31 20:43 ` Florian Weimer
2021-12-31 20:52 ` H.J. Lu
2021-12-31 21:02 ` Florian Weimer
2021-12-31 21:15 ` Noah Goldstein
2021-12-31 22:05 ` Florian Weimer [this message]
2021-12-31 22:14 ` Noah Goldstein
2021-12-31 22:19 ` Noah Goldstein
2021-12-31 22:21 ` H.J. Lu
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