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From: "gael.guennebaud at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/53900] New: Too optimistic on a alignment assert Date: Mon, 09 Jul 2012 14:57:00 -0000 [thread overview] Message-ID: <bug-53900-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53900 Bug #: 53900 Summary: Too optimistic on a alignment assert Classification: Unclassified Product: gcc Version: 4.7.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: gael.guennebaud@gmail.com Created attachment 27766 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27766 an example triggering the issue. Since gcc 4.7 the assertion of the attached piece of code is resolved at compile-time while there is no guaranty, for instance when using a non-aligned memory allocator, or on some systems where function arguments cannot be aligned. Here is the output with gcc-4.7: $ g++-4.7 -m32 alignedassert.cpp && ./a.out 0x8321008 0x832100c no assertion! And with gcc 4.6: $ g++-4.6 -m32 alignedassert.cpp && ./a.out 0x9322008 a.out: alignedassert.cpp:12: Foo::Foo(): Assertion `(std::ptrdiff_t(array) & std::ptrdiff_t(0xf))==0' failed. Aborted Or without the -m32 flag: $ g++-4.7 alignedassert.cpp && ./a.out 0xde3010 0xde3014 $ g++-4.6 alignedassert.cpp && ./a.out 0x1f03010 0x1f03014 a.out: alignedassert.cpp:12: Foo::Foo(): Assertion `(std::ptrdiff_t(array) & std::ptrdiff_t(0xf))==0' failed. Aborted
next reply other threads:[~2012-07-09 14:57 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-07-09 14:57 gael.guennebaud at gmail dot com [this message] 2012-07-09 15:23 ` [Bug c++/53900] [regression] " rguenth at gcc dot gnu.org 2012-07-09 16:12 ` gael.guennebaud at gmail dot com 2012-07-09 16:19 ` rguenth at gcc dot gnu.org 2012-07-10 11:09 ` gael.guennebaud at gmail dot com 2012-12-28 17:47 ` xarthisius.kk at gmail dot com 2013-01-07 4:27 ` pinskia at gcc dot gnu.org 2013-01-07 10:19 ` chtz at informatik dot uni-bremen.de 2013-01-07 10:22 ` pinskia at gcc dot gnu.org 2015-02-19 15:27 ` jacob.benoit.1 at gmail dot com
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