linux-kernel - Re: [PATCH] trivial: the memset operation on a automatic array variable should be optimized out by data initialization

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]

Message-Id: <1182730156.6819.8.camel@laptopd505.fenrus.org>
Date:	Sun, 24 Jun 2007 17:09:16 -0700
From:	Arjan van de Ven <arjan@...radead.org>
To:	Benjamin LaHaise <bcrl@...ck.org>
Cc:	Oleg Verych <olecom@...wer.upol.cz>, rae l <crquan@...il.com>,
	trivial@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] trivial: the memset operation on a automatic array
	variable should be optimized out by data initialization

On Sun, 2007-06-24 at 19:23 -0400, Benjamin LaHaise wrote:
> On Sun, Jun 24, 2007 at 03:15:17PM -0700, Arjan van de Ven wrote:
> > we should just alias our memset to the __builtin one, and then provide a
> > generic one from lib/ for the cases gcc needs to do a fallback.
> 
> The last time I checked, gcc generated horrible badly performing code for 
> builtin memset/memcpy() when -Os is specified.

if you care about the last cycle, don't specify -Os but -O2.
simple as that... you get what you tell the compiler you want.

-- 
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

-
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/