linux-kernel - Re: [RFC][PATCH 3/3] math128, x86_64: Implement {mult,add}

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 for Android: free password hash cracker in your pocket

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

Date:	Tue, 24 Apr 2012 19:19:33 +0200
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Juri Lelli <juri.lelli@...il.com>,
	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [RFC][PATCH 3/3] math128, x86_64: Implement {mult,add}_u128 in
 64bit asm

On Tue, 2012-04-24 at 10:17 -0700, H. Peter Anvin wrote:
> On 04/24/2012 09:36 AM, Peter Zijlstra wrote:
> > On Tue, 2012-04-24 at 09:34 -0700, H. Peter Anvin wrote:
> >> On 04/24/2012 09:10 AM, Peter Zijlstra wrote:
> >>
> >> Are you sure that gcc won't simply generate this code already if given
> >> "unsigned __int128"?
> > 
> > It might, but I've been told some GCC versions had issues, also lots of
> > archs fall back to libgcc functions.
> > 
> 
> Yes, but this is specific to x86-64.  If gcc can generate the code it
> can also schedule the code, which it can't for assembly...

Ok, but are you sure unsigned __int128 works for all gcc versions we
support?
--
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/