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From: "lothar at tradescape dot biz" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/36861] New: code generation regression with -O3 Date: Thu, 17 Jul 2008 07:28:00 -0000 [thread overview] Message-ID: <bug-36861-11487@http.gcc.gnu.org/bugzilla/> (raw) gcc 4.3.1 generates code with -O3 that is more than 10 times slower than with -O0. gcc 4.2.3 does not show this behavior. I am going to attach the test case that I used to produce these numbers: with gcc 4.2.3: ( time ./avltest-nn >/dev/null; time ./avltest-no >/dev/null; time ./avltest-on >/dev/null; time ./avltest-oo >/dev/null; ) real 0m1.112s user 0m1.028s sys 0m0.012s real 0m0.078s user 0m0.060s sys 0m0.008s real 0m0.940s user 0m0.916s sys 0m0.008s real 0m0.088s user 0m0.072s sys 0m0.004s with gcc 4.3.1: ( time ./avltest-nn >/dev/null; time ./avltest-no >/dev/null; time ./avltest-on >/dev/null; time ./avltest-oo >/dev/null; ) real 0m0.974s user 0m0.948s sys 0m0.004s real 0m12.936s user 0m12.893s sys 0m0.016s real 0m1.128s user 0m1.012s sys 0m0.000s real 0m0.104s user 0m0.076s sys 0m0.004s Here is the information about the compilers used: $ /opt2/linux/ix86/bin/g++-4.2.3 -v Using built-in specs. Target: x86_64-pc-linux-gnu Configured with: ../gcc-4.2.3/configure --program-suffix=-4.2.3 --enable-__cxa_atexit --enable-languages=c,c++,java --prefix=/opt2/linux/ix86 --target=x86_64-pc-linux-gnu --with-sysroot=/opt2/linux/ix86/gcc-sysroot --enable-version-specific-runtime-libs --enable-clocale=gnu Thread model: posix gcc version 4.2.3 $ /opt2/linux/ix86/bin/g++-4.3.1 -v Using built-in specs. Target: x86_64-pc-linux-gnu Configured with: ../gcc-4.3.1/configure --enable-targets=all --enable-multilib --enable-__cxa_atexit --enable-languages=c,c++,java --enable-version-specific-runtime-libs --disable-nls --enable-clocale=gnu --program-suffix=-4.3.1 --prefix=/opt2/linux/ix86 --target=i686-pc-linux-gnu --target=x86_64-pc-linux-gnu --with-sysroot=/opt2/linux/ix86/gcc-sysroot Thread model: posix gcc version 4.3.1 (GCC) -- Summary: code generation regression with -O3 Product: gcc Version: 4.3.1 Status: UNCONFIRMED Severity: major Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: lothar at tradescape dot biz GCC target triplet: x86_64-pc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36861
next reply other threads:[~2008-07-17 7:28 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-07-17 7:28 lothar at tradescape dot biz [this message] 2008-07-17 7:29 ` [Bug c++/36861] " lothar at tradescape dot biz 2008-07-17 16:55 ` lothar at tradescape dot biz 2008-07-17 17:44 ` rguenth at gcc dot gnu dot org 2008-07-17 17:48 ` [Bug tree-optimization/36861] " pinskia at gcc dot gnu dot org 2008-07-17 17:51 ` lothar at tradescape dot biz 2008-07-17 17:53 ` lothar at tradescape dot biz 2008-07-17 18:02 ` rguenth at gcc dot gnu dot org 2008-07-17 18:10 ` lothar at tradescape dot biz 2008-07-17 18:29 ` [Bug tree-optimization/36861] [4.3 Regression] " rguenth at gcc dot gnu dot org 2008-07-17 20:15 ` lothar at tradescape dot biz 2008-07-17 20:20 ` rguenth at gcc dot gnu dot org 2008-07-22 21:44 ` [Bug tree-optimization/36861] boost's compressed avl confuses GCC pinskia at gcc dot gnu dot org 2008-07-22 21:49 ` lothar at tradescape dot biz 2008-07-22 21:53 ` pinskia at gcc dot gnu dot org 2008-07-22 22:01 ` lothar at tradescape dot biz 2008-07-23 8:04 ` igaztanaga at gmail dot com 2008-07-24 22:19 ` [Bug tree-optimization/36861] [4.3 Regression] " drow at gcc dot gnu dot org 2008-07-28 18:56 ` lothar at tradescape dot biz 2008-07-31 2:03 ` lothar at tradescape dot biz 2008-07-31 7:57 ` aldot at gcc dot gnu dot org 2008-08-29 4:41 ` pinskia at gcc dot gnu dot org 2008-09-20 14:27 ` [Bug tree-optimization/36861] [4.3/4.4 " rguenth at gcc dot gnu dot org 2008-09-20 14:28 ` rguenth at gcc dot gnu dot org 2008-10-10 16:00 ` [Bug target/36861] " lothar at tradescape dot biz 2008-10-22 3:03 ` mmitchel at gcc dot gnu dot org 2009-01-24 10:28 ` rguenth at gcc dot gnu dot org 2009-02-03 9:54 ` bonzini at gnu dot org 2009-08-04 12:41 ` [Bug target/36861] [4.3/4.4/4.5 " rguenth at gcc dot gnu dot org 2010-03-16 13:15 ` [Bug target/36861] [4.5 " rguenth at gcc dot gnu dot org 2010-04-06 11:21 ` rguenth at gcc dot gnu dot org 2010-07-05 15:40 ` [Bug target/36861] [4.5/4.6 " rguenth at gcc dot gnu dot org 2010-07-05 16:03 ` rguenth at gcc dot gnu dot org 2010-07-31 9:35 ` rguenth at gcc dot gnu dot org
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