From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1117 invoked by alias); 16 Jul 2002 05:16:03 -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 1086 invoked by uid 71); 16 Jul 2002 05:16:01 -0000 Date: Mon, 15 Jul 2002 22:16:00 -0000 Message-ID: <20020716051601.1079.qmail@sources.redhat.com> To: amodra@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Alan Modra Subject: Re: other/7114: ICE building strcoll.op from glibc-2.2.5 Reply-To: Alan Modra X-SW-Source: 2002-07/txt/msg00480.txt.bz2 List-Id: The following reply was made to PR other/7114; it has been noted by GNATS. From: Alan Modra To: Richard Henderson , Geoff Keating , d.mueller@elsoft.ch, gcc-gnats@gcc.gnu.org, gcc-patches@gcc.gnu.org, dje@watson.ibm.com Cc: Subject: Re: other/7114: ICE building strcoll.op from glibc-2.2.5 Date: Tue, 16 Jul 2002 14:38:08 +0930 On Mon, Jul 15, 2002 at 09:31:24PM -0700, Richard Henderson wrote: > On Tue, Jul 16, 2002 at 11:08:16AM +0930, Alan Modra wrote: > > It gets worse. rs6000/sysv4.h sets PROFILE_BEFORE_PROLOGUE. > > Make rs6000/sysv4.h can use PROFILE_HOOK instead. Aye, that's the nice way to do it. However, on powerpc64-linux, I've had kernel people complaining that the profiling code isn't what they want: All those register saves from the prologue preceding the mcount call apparently are messing up accurate count values, and it's hard for an mcount implementation to adjust times, or so I'm told. I implemented a simple hack to do PROFILE_BEFORE_PROLOGUE on powerpc64-linux for people who want it. I suspect we'll get the same sort of complaint if we change powerpc mcount. There's also the issue that some special-purpose mcount functions may expect to be called before the stack has been adjusted. I'm rapidly approaching the point where I either give up on this problem, or simply remove support for profiling on nested functions. The current code just doesn't work.