From: Steve Ellcey <sellcey@mips.com>
To: "Ondřej Bílka" <neleai@seznam.cz>
Cc: <libc-ports@sourceware.org>
Subject: Re: [Patch, mips] Faster strcmp for mips
Date: Mon, 18 Nov 2013 23:50:00 -0000 [thread overview]
Message-ID: <1384817878.2484.137.camel@ubuntu-sellcey> (raw)
In-Reply-To: <20131115190200.GA28546@domone.podge>
On Fri, 2013-11-15 at 20:02 +0100, Ondøej BĂlka wrote:
> I decided that using ffls was shorter but for some reasons I kept
> bitfirst there. A correct version is
>
> uint64_t bitmask = DETECTNULL8(x) | (x ^ y);
> int pos = (ffsl(bitmask) - 1) / 8;
> return a[pos] - b[pos];
Yes, that works much better. But it only works in little-endian mode. I
think I would need a fls (find last set) or something similar for
big-endian wouldn't I? Or else I would need to swap the bytes around
before using ffs/ffsl.
Steve Ellcey
sellcey@mips.com
next prev parent reply other threads:[~2013-11-18 23:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-14 21:25 Steve Ellcey
2013-11-14 23:14 ` Ondřej Bílka
2013-11-15 18:21 ` Steve Ellcey
2013-11-15 19:02 ` Ondřej Bílka
2013-11-18 23:50 ` Steve Ellcey [this message]
2013-11-19 2:32 ` Ondřej Bílka
2013-11-15 18:48 ` Carlos O'Donell
2013-11-15 18:53 ` Steve Ellcey
2013-11-15 18:59 ` Carlos O'Donell
2015-02-19 7:25 ` Matt Turner
2015-02-19 18:12 ` Steve Ellcey
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