linux-kernel - Re: [PATCH] add slice by 8 algorithm to crc32.c

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	8 Aug 2011 06:52:01 -0400
From:	"George Spelvin" <linux@...izon.com>
To:	joakim.tjernlund@...nsmode.se, linux@...izon.com
Cc:	akpm@...ux-foundation.org, fzago@...temfabricworks.com,
	linux-kernel@...r.kernel.org, rpearson@...temfabricworks.com
Subject: Re: [PATCH] add slice by 8 algorithm to crc32.c

> I prefer to keep the current code which (at the time) generated good code
> for at least ppc:
> 	/* Align it */
> 	if (unlikely((long)buf & 3 && len)) {
> 		do {
> 			DO_CRC(*buf++);
> 		} while ((--len) && ((long)buf)&3);
> 	}

Ah, I was looking at fzago's initial patch; I hadn't realized you'd
tweaked it.  That's pretty much what I was talking about.

Would
 	if (unlikely((long)buf & 3) && len) {

give the compiler better hints?  len != 0 is awfully
likely, actually.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/