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From: Andi Kleen <andi@firstfloor.org>
To: Joe Damato <ice799@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	Andi Kleen <andi@firstfloor.org>, Ingo Molnar <mingo@elte.hu>,
	Jeff Garzik <jeff@garzik.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org
Subject: Re: [PATCH] X86-32: Let gcc decide whether to inline memcpy was Re: New x86 warning
Date: Fri, 24 Apr 2009 10:44:19 +0200	[thread overview]
Message-ID: <20090424084419.GH13896@one.firstfloor.org> (raw)
In-Reply-To: <3605561d0904231422s57bd4cedl722be1dabf27428f@mail.gmail.com>

> gcc 4.2.4 - withOUT memset patch: 20
> gcc 4.2.4 - with memset patch: 365
> 
> gcc 3.4 - withOUT memset patch: 17
> gcc 3.4 - with memset patch: 349

Yes it sounds like 3.4 is worse on that than 3.2. Too bad.

> I'm guessing this is probably not acceptable, so I won't bother

It depends if the calls are in critical code. Or how big they
are (for a 1K memset it's totally fine to have it out of line).

For example for any memsets in __init functions we wouldn't
care. You could filter those out. And perhaps eyeball the code.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

  parent reply	other threads:[~2009-04-24  8:40 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-22  6:46 New x86 warning Jeff Garzik
2009-04-22  7:01 ` Ingo Molnar
2009-04-22  8:45   ` [PATCH] X86-32: Let gcc decide whether to inline memcpy was " Andi Kleen
2009-04-22 18:00     ` [tip:x86/asm] x86: use __builtin_memcpy() on 32 bits tip-bot for Andi Kleen
2009-04-22 20:56     ` [PATCH] X86-32: Let gcc decide whether to inline memcpy was Re: New x86 warning Linus Torvalds
2009-04-22 21:15       ` Andi Kleen
2009-04-22 21:19         ` Linus Torvalds
2009-04-22 22:04           ` Andi Kleen
2009-04-23  6:08             ` fresh data was " Andi Kleen
2009-04-23  6:36               ` Ingo Molnar
2009-04-23  7:37                 ` Andi Kleen
2009-04-23  6:30             ` Ingo Molnar
2009-04-23  7:43               ` Andi Kleen
2009-04-22 23:49     ` Joe Damato
2009-04-23  1:48       ` H. Peter Anvin
2009-04-23 21:22         ` Joe Damato
2009-04-23 22:09           ` H. Peter Anvin
2009-04-24  8:44           ` Andi Kleen [this message]
2009-04-23  6:09       ` Andi Kleen

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