From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Jacobowitz Subject: Re: i386 inline-asm string functions - some questions Date: Mon, 29 Dec 2003 00:31:52 -0500 Sender: libc-alpha-owner@sources.redhat.com Message-ID: <20031229053151.GA7231@nevyn.them.org> References: <20031225064518.F7419@zzz.ward.six> <87d6acjlfp.fsf@egil.codesourcery.com> <20031227045815.GA14291@redhat.com> <87fzf6mubo.fsf@egil.codesourcery.com> <20031227163540.B6728@zzz.ward.six> <87brpum7gm.fsf@egil.codesourcery.com> <20031229015820.C6728@zzz.ward.six> <871xqol5wv.fsf@codesourcery.com> <3FEFA115.90704@redhat.com> <87k74gjmyh.fsf@codesourcery.com> Mime-Version: 1.0 Return-path: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Content-Disposition: inline In-Reply-To: <87k74gjmyh.fsf@codesourcery.com> List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Zack Weinberg Cc: Ulrich Drepper , Richard Henderson , Andreas Jaeger , libc-alpha@sources.redhat.com, linux-gcc@vger.kernel.org, gcc@gcc.gnu.org On Sun, Dec 28, 2003 at 07:56:54PM -0800, Zack Weinberg wrote: > Ulrich Drepper writes: > > > Zack Weinberg wrote: > >> I once tried to get Uli to take them out again, with > >> hard numbers to back me up, but he ignored me. > > > > I have absolutely no problem taking out the inlines once gcc is able to > > perform the same optimizations. Problem is that nobody spent the time > > so far to complete the task in gcc. > > This is true - I believe Joseph Myers put a list of yet-to-be-done > optimizations on the GCC projects page ... > > > As far as I know each function we still have has an advantage over > > the gcc code. > > ... however, that advantage is only theoretical. Experiments such as > Peter Zaitsev's just now, and mine several years ago, demonstrate that > the bits/string.h and bits/string2.h inlines make code worse, not better. > Therefore they should be removed. Funny, I conducted this experiment last week and found quite the opposite. Compiling the demangler and a smallish yacc parser with -D__NO_STRING_INLINES cost about 20% in runtime. I'm not convinced. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer