From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15021 invoked by alias); 14 Jun 2012 22:47:32 -0000 Received: (qmail 15011 invoked by uid 22791); 14 Jun 2012 22:47:31 -0000 X-SWARE-Spam-Status: No, hits=-3.6 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 14 Jun 2012 22:47:18 +0000 From: "matt at use dot net" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/53676] New: [4.7/4.8 regression] constant folding regression, shown as slowdown as measured by Adobe's C++Benchmark Date: Thu, 14 Jun 2012 22:47:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Keywords: X-Bugzilla-Severity: major X-Bugzilla-Who: matt at use dot net X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 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 X-SW-Source: 2012-06/txt/msg00959.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53676 Bug #: 53676 Summary: [4.7/4.8 regression] constant folding regression, shown as slowdown as measured by Adobe's C++Benchmark Classification: Unclassified Product: gcc Version: 4.7.1 Status: UNCONFIRMED Severity: major Priority: P3 Component: middle-end AssignedTo: unassigned@gcc.gnu.org ReportedBy: matt@use.net The attached ZIP contains two binaries and preprocessor output files, based on a subset of a test in Adobe's C++Benchmark suite. All GCC versions I tested prior to 4.7 do the folding correctly. I tried using Ofast and other tricks to workaround this new regression to no avail. -rw-r--r-- 1 mhargett users 143573 Jun 14 15:31 int8_folding_test.gcc47.i mhargett@chert:~/src/C++Benchmarks-gcc47-google-fast$ ./int8_folding_test-gcc46 ./int8_folding_test-gcc46 test description absolute operations ratio with number time per second test0 0 "int8_t constant" 0.00 sec inf M -nan Total absolute time for int8_t simple constant folding: 0.00 sec mhargett@chert:~/src/C++Benchmarks-gcc47-google-fast$ ./int8_folding_test-gcc47 ./int8_folding_test-gcc47 test description absolute operations ratio with number time per second test0 0 "int8_t constant" 0.69 sec 2318.84 M 1.00 Total absolute time for int8_t simple constant folding: 0.69 sec