From: "Wilco Dijkstra" <wdijkstr@arm.com>
To: "'Ondřej Bílka'" <neleai@seznam.cz>
Cc: <libc-alpha@sourceware.org>
Subject: RE: [PATCH][PING] Improve stpncpy performance
Date: Thu, 09 Jul 2015 15:02:00 -0000 [thread overview]
Message-ID: <000c01d0ba58$44d1c170$ce754450$@com> (raw)
In-Reply-To: <20150709110655.GA29253@domone>
> Ondřej Bílka wrote:
>
> You don't have to use special case
>
> if (size == n)
> return dest;
>
> as it should be handled by
>
> return memset (dest, '\0', 0);
>
> That could improve performance a bit if its rare case. That doesn't
> matter much as memset makes that function slow and it shouldn't be
> used in performance sensitive code.
>
> Otherwise ok for me.
On the benchtests the extra if made a significant difference, particularly
since memset of 0 is relatively expensive as it is being regarded as a very
rare case. It seems it should be less likely than the benchtests indicate,
but we'd have to fix the benchtest first to use more realistic data.
Wilco
next prev parent reply other threads:[~2015-07-09 15:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-06 11:29 Wilco Dijkstra
2015-07-09 13:21 ` Ondřej Bílka
2015-07-09 15:02 ` Wilco Dijkstra [this message]
2015-08-12 20:57 ` Ondřej Bílka
2015-08-19 16:15 ` Wilco Dijkstra
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