linux-kernel - Re: [PATCH] memchr (trivial) optimization

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Message-ID: <46CE2E61.9010408@goop.org>
Date:	Thu, 23 Aug 2007 18:03:29 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Matt Mackall <mpm@...enic.com>
CC:	Ingo Oeser <ioe-lkml@...eria.de>,
	lode leroy <lode_leroy@...mail.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] memchr (trivial) optimization

Matt Mackall wrote:
>   6e:   38 08                   cmp    %cl,(%eax)
>   70:   74 07                   je     79 <memchr3+0x1b>
>   72:   40                      inc    %eax
>   
It's a bit gross that the compiler is using inc here rather than lea or
add, but still...

Er, something's spending 30% of its time in memchr?  This is not the
code to fix.

    J
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