From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
To: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Cc: 'GNU C Library' <libc-alpha@sourceware.org>
Subject: Re: [PATCH v12 14/31] string: Improve generic strrchr with memrchr and strlen
Date: Fri, 3 Feb 2023 09:15:38 -0300 [thread overview]
Message-ID: <28462546-34c9-5a09-599e-bb66959db500@linaro.org> (raw)
In-Reply-To: <PAWPR08MB8982A27C2B0AF83BFC1EC91883D69@PAWPR08MB8982.eurprd08.prod.outlook.com>
On 02/02/23 16:54, Wilco Dijkstra wrote:
> Hi Adhemerval,
>
> STRRCHR (const char *s, int c)
> {
> + return __memrchr (s, c, strlen (s) + 1);
> }
>
> LGTM
>
> I did a quick check on AArch64 and the speedup vs the old generic version
> on bench-strrchr is 9.9 times! It's ~15% slower overall than the assembler
> strrchr.
>
> While the benchmark is not perfect, it shows that if you have decent strlen
> and memrchr then strlen+memchr gives a competitive strrchr.
Yeah, I saw a similar improvement on my side as well. Thanks for verify it
as well.
next prev parent reply other threads:[~2023-02-03 12:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-02 19:54 Wilco Dijkstra
2023-02-03 12:15 ` Adhemerval Zanella Netto [this message]
-- strict thread matches above, loose matches on Subject: below --
2023-02-02 18:11 [PATCH v12 00/31] Improve generic string routines Adhemerval Zanella
2023-02-02 18:11 ` [PATCH v12 14/31] string: Improve generic strrchr with memrchr and strlen Adhemerval Zanella
2023-02-04 3:06 ` Richard Henderson
2023-02-06 14:01 ` Adhemerval Zanella Netto
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