Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964909AbVL1VCi (ORCPT ); Wed, 28 Dec 2005 16:02:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964911AbVL1VCi (ORCPT ); Wed, 28 Dec 2005 16:02:38 -0500 Received: from smtp.osdl.org ([65.172.181.4]:19126 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S964909AbVL1VCh (ORCPT ); Wed, 28 Dec 2005 16:02:37 -0500 Date: Wed, 28 Dec 2005 13:02:24 -0800 (PST) From: Linus Torvalds To: Arjan van de Ven cc: Ingo Molnar , lkml , Andrew Morton , Matt Mackall Subject: Re: [patch 00/2] improve .text size on gcc 4.0 and newer compilers In-Reply-To: <1135798495.2935.29.camel@laptopd505.fenrus.org> Message-ID: References: <20051228114637.GA3003@elte.hu> <1135798495.2935.29.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1322 Lines: 33 On Wed, 28 Dec 2005, Arjan van de Ven wrote: > > yup that's why the patch only does it for gcc4, in which the inlining > heuristics finally got rewritten to something that seems to resemble > sanity... Is that actually true of all gcc4 versions? I seem to remember gcc-4.0 being a real stinker. > > Also, the inlining patch apparently makes code larger in some cases, > > so it's not even a unconditional win. > > .... as long as you give the inlining algorithm enough information. > -fno-unit-at-a-time prevents gcc from having the information, and the > decisions it makes are then less optimal... > > (unit-at-a-time allows gcc to look at the entire .c file, eg things like > number of callers etc etc, disabling that tells gcc to do the .c file as > single pass top-to-bottom only) I'd still prefer to see numbers with -funit-at-a-time only. I think it's an independent knob, and I'd be much less worried about that, because we do know that unit-at-a-time has been enabled on x86-64 for a long time ("forever"). So that's less of a change, I feel. Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/