From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13668 invoked by alias); 14 Oct 2014 14:42:32 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 13644 invoked by uid 55); 14 Oct 2014 14:42:28 -0000 From: "tejohnson at google dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug bootstrap/63432] [5 Regression] profiledbootstrap failure with bootstrap-lto Date: Tue, 14 Oct 2014 14:42:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: bootstrap X-Bugzilla-Version: 5.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: tejohnson at google dot com X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2014-10/txt/msg01072.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63432 --- Comment #29 from Teresa Johnson --- On Mon, Oct 13, 2014 at 2:32 PM, Teresa Johnson wrote: > On Mon, Oct 13, 2014 at 8:53 AM, hjl.tools at gmail dot com > wrote: >> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63432 >> >> --- Comment #27 from H.J. Lu --- >> (In reply to Teresa Johnson from comment #24) >> >>> Arg, looks very similar so maybe another instance of the duplicate >>> threading is slipping through? My own lto profiled bootstrap succeeded >>> with my patch. I will try updating to r216039 and redo it to see if I >>> can provoke the same failure. >>> >> >> I sent you another testcase against r216150. > > Thanks for the testcase, I reproduced it. It is a case of garbage in / > garbage out. The fre2 pass is introducing some big profile count > insanities, leading to the probability insanity being introduced when > we try to use the counts to compute the new probability in > recompute_probabilities. There is already handling for really large > probabilities due to this issue, and we need to add the same thing for > negative probabilities - essentially the patch you had originally > suggested for the first problem which wasn't necessary for that one > since that was an actually jump threading induced issue. Actually, I traced the initial profile insanity back to inlining. FRE merely propagated it further. I have a better overflow test done before the scaling, running it through LTO profiledbootstrap then will send for review. Teresa > > Will test that and send for review. > >> >> -- >> You are receiving this mail because: >> You are on the CC list for the bug. > > > > -- > Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413