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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/49651] [C++0x] nested lambdas and -O3 produced incorrect integer variable increments Date: Thu, 14 Jul 2011 12:27:00 -0000 [thread overview] Message-ID: <bug-49651-4-hyyE9lbA3p@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-49651-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49651 Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED AssignedTo|unassigned at gcc dot |rguenth at gcc dot gnu.org |gnu.org | --- Comment #8 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-07-14 12:26:08 UTC --- In the optimized dump I can see <bb 4>: ... run.__v7 = &v7; run.__a = &a; ... <bb 6>: # ivtmp.207_17 = PHI <ivtmp.207_68(10), ivtmp.207_69(5)> D.47092_58 = a; D.47093_59 = D.47092_58 + 1; a = D.47093_59; f (D.47092_58); <bb 7>: D.47084_60 = MEM[(int * const &)&ve + 8]; D.47090._M_current = D.47084_60; D.47083_61 = MEM[(int * const &)&ve]; D.47089._M_current = D.47083_61; D.47091 = std::for_each<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, main(int, char**)::<lambda(int&)> > (D.47089, D.47090, run); <bb 8>: D.47093_63 = D.47092_58 + 2; a = D.47093_63; f (D.47093_59); <bb 9>: D.47082_64 = MEM[(int * const &)&ve + 8]; D.47086._M_current = D.47082_64; D.47081_65 = MEM[(int * const &)&ve]; D.47085._M_current = D.47081_65; D.47087 = std::for_each<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, main(int, char**)::<lambda(int&)> > (D.47085, D.47086, run); <bb 10>: ivtmp.207_68 = ivtmp.207_17 + 4; __first$_M_current_66 = (int *) ivtmp.207_68; if (__last_27 != __first$_M_current_66) goto <bb 6>; else ... so we do CSE a over the std::for_each invocation which gets run as argument. That's wrong of course. Alias-info tells us even that a is clobbered by that call: # USE = nonlocal null { aD.40068 viD.40071 D.40875 veD.40876 D.40877 v7D.40878 } # CLB = nonlocal null { aD.40068 viD.40071 D.40875 veD.40876 D.40877 v7D.40878 } D.47091 = std::for_each<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, main(int, char**)::<lambda(int&)> > (D.47089, D.47090, runD.40880); but it doesn't do so at the time when the first FRE is run: # USE = nonlocal null { viD.40071 D.40875 veD.40876 D.40877 v7D.40878 } # CLB = nonlocal null { viD.40071 D.40875 veD.40876 D.40877 v7D.40878 } D.47091 = std::for_each<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, main(int, char**)::<lambda(int&)> > (D.47089, D.47090, *__f$__runD.47077_57); the setup there is still not very optimized though.
next prev parent reply other threads:[~2011-07-14 12:27 UTC|newest] Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-07-05 20:15 [Bug c++/49651] New: " pedro.larroy at gmail dot com 2011-07-05 20:30 ` [Bug c++/49651] " pedro.larroy at gmail dot com 2011-07-05 21:54 ` redi at gcc dot gnu.org 2011-07-05 22:24 ` pedro.larroy at gmail dot com 2011-07-05 23:54 ` redi at gcc dot gnu.org 2011-07-12 14:39 ` [Bug tree-optimization/49651] " jason at gcc dot gnu.org 2011-07-12 15:21 ` rguenth at gcc dot gnu.org 2011-07-13 12:32 ` rguenth at gcc dot gnu.org 2011-07-14 12:27 ` rguenth at gcc dot gnu.org [this message] 2011-07-14 12:37 ` rguenth at gcc dot gnu.org 2011-07-14 13:02 ` [Bug tree-optimization/49651] [4.4/4.5/4.6/4.7 Regression] " rguenth at gcc dot gnu.org 2011-07-14 14:54 ` rguenth at gcc dot gnu.org 2011-07-14 14:57 ` rguenth at gcc dot gnu.org 2011-07-14 15:01 ` [Bug tree-optimization/49651] [4.4/4.5 " rguenth at gcc dot gnu.org 2011-08-01 14:09 ` rguenth at gcc dot gnu.org 2011-08-01 16:00 ` pedro.larroy at gmail dot com 2012-01-04 9:48 ` rguenth at gcc dot gnu.org 2012-01-04 9:50 ` rguenth at gcc dot gnu.org 2012-01-04 11:55 ` rguenth at gcc dot gnu.org 2012-01-04 11:56 ` [Bug tree-optimization/49651] [4.4 " rguenth at gcc dot gnu.org 2012-03-13 17:00 ` jakub at gcc dot gnu.org
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