From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8397 invoked by alias); 10 Feb 2004 16:09:32 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 8360 invoked by uid 48); 10 Feb 2004 16:09:30 -0000 Date: Tue, 10 Feb 2004 16:09:00 -0000 Message-ID: <20040210160930.8359.qmail@sources.redhat.com> From: "pcarlini at suse dot de" To: gcc-bugs@gcc.gnu.org In-Reply-To: <20040209093043.14078.peturr02@ru.is> References: <20040209093043.14078.peturr02@ru.is> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug libstdc++/14078] Manipulators are slow X-Bugzilla-Reason: CC X-SW-Source: 2004-02/txt/msg01130.txt.bz2 List-Id: ------- Additional Comments From pcarlini at suse dot de 2004-02-10 16:09 ------- > The only reason I suggested that the argument should be declared const is > that it seems to make a difference in practice (in fact, about 44%). I > don't know why it does though, the compiler should be able to figure out > on it's own that pf isn't modified in the body of the function. These are well known deficiencies of the inliner http://gcc.gnu.org/ml/libstdc++/2003-02/msg00302.html which, I'm told, should be already fixed "automatically" in the tree-ssa branch. For this reason, I'd rather prefer not adding the "redundant" const in the signature, even if (thanks for pointing that out!) technically it would still be conforming. Anyway, I'm going to add to the performance testsuite a snippet distilled from your manipspeed, so we'll be able to track the issue in the future. Thanks again for your report. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14078