From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14186 invoked by alias); 15 Nov 2002 22:46:04 -0000 Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-prs-owner@gcc.gnu.org Received: (qmail 14132 invoked by uid 71); 15 Nov 2002 22:46:03 -0000 Date: Thu, 21 Nov 2002 14:01:00 -0000 Message-ID: <20021115224603.14119.qmail@sources.redhat.com> To: bkoz@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Richard Henderson Subject: Re: libstdc++/8230: Buggy allocator behaviour Reply-To: Richard Henderson X-SW-Source: 2002-11/txt/msg00786.txt.bz2 List-Id: The following reply was made to PR libstdc++/8230; it has been noted by GNATS. From: Richard Henderson To: Gabriel Dos Reis Cc: Matt Austern , Benjamin Kosnik , bkoz@gcc.gnu.org, gcc-bugs@gcc.gnu.org, jkanze@caicheuvreux.com, gcc-gnats@gcc.gnu.org, libstdc++@gcc.gnu.org Subject: Re: libstdc++/8230: Buggy allocator behaviour Date: Fri, 15 Nov 2002 14:41:38 -0800 On Thu, Nov 14, 2002 at 11:27:17PM +0100, Gabriel Dos Reis wrote: > Maybe RTH could provide us with some datapoint here? "It depends". > | Second, if the answer to question 1 is "a lot": is there some sensible > | way to use this in the compiler itself? I suppose it'd have to involve > | some ghastly macro hackery because of the bootstrap problem, but > | it we're talking big performance wins, it might be worth it. > > If the answer to the first question is "a lot", then I agree with you > that it makes perfect sense to use it in the compiler itself. I > could imagine something along the lines > > #if !defined(__GNUC__) || __GNUC__ < 3 /* correct the version number */ > # define __builtin_expect(EXP, PROB) EXP > #endif > > in system.h or wherever appropriate. I don't think it's worth it, except _possibly_ in the ENABLE_CHECKING macros. r~