From: Joseph Myers <joseph@codesourcery.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: <libc-alpha@sourceware.org>
Subject: Re: [PATCH] elf: Replace memcmp with __memcmpeq for variable size
Date: Mon, 7 Feb 2022 20:35:43 +0000 [thread overview]
Message-ID: <alpine.DEB.2.22.394.2202072032370.9395@digraph.polyomino.org.uk> (raw)
In-Reply-To: <20220206210914.1593336-1-hjl.tools@gmail.com>
On Sun, 6 Feb 2022, H.J. Lu via Libc-alpha wrote:
> Replace memcmp with __memcmpeq when a boolean return is all that is
> needed. __memcmpeq is an alias of memcmp by default and it can be
> optimized by architectures.
I don't think we should make this sort of change to glibc source code at
all. We should write the code to be clear for readers - meaning using the
standard C function name, which is memcmp - and leave the compiler to
optimize or not.
In general we should move away from writing such internal function calls
directly in the source code, where it can reasonably call the standard
function names instead. Cf. how we handle things for various internal
calls in libm: call standard names the compiler might inline (don't
provide e.g. inline versions of those functions in glibc's internal
headers), with asm redirection to reserved names to cover the case when
those function calls don't get inlined.
--
Joseph S. Myers
joseph@codesourcery.com
next prev parent reply other threads:[~2022-02-07 20:35 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-06 21:09 H.J. Lu
2022-02-06 22:19 ` Florian Weimer
2022-02-07 0:20 ` H.J. Lu
2022-02-07 10:40 ` Florian Weimer
2022-02-07 13:13 ` H.J. Lu
2022-02-07 13:19 ` Florian Weimer
2022-02-07 13:27 ` H.J. Lu
2022-02-07 13:30 ` Adhemerval Zanella
2022-02-07 14:00 ` H.J. Lu
2022-02-07 20:35 ` Joseph Myers [this message]
2022-02-08 22:30 Wilco Dijkstra
2022-02-08 23:00 ` Adhemerval Zanella
2022-02-09 0:07 ` Noah Goldstein
2022-02-09 1:42 ` Wilco Dijkstra
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