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* [Bug c/31291] New: Different (wrong?) behaviour using ffps when enabling optimizing @ 2007-03-21 7:13 mail at sebastianbauer dot info 2007-03-21 7:14 ` [Bug c/31291] " mail at sebastianbauer dot info ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: mail at sebastianbauer dot info @ 2007-03-21 7:13 UTC (permalink / raw) To: gcc-bugs The purpose of the attached code is to print out the internal representation of some floating points. However, when compiling with optimizations turned on the behaviour of the compiled program is not the expected one (i.e. the proper hex representation is not printed out, but something else, here 0). I encounter this behaviour on amd64 debian as on windows using cygwin gcc. I'm going to attach the debian output of compilation and invocation. -- Summary: Different (wrong?) behaviour using ffps when enabling optimizing Product: gcc Version: 4.1.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: mail at sebastianbauer dot info GCC build triplet: x86_64 GCC host triplet: x86_64 GCC target triplet: x86_64 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31291 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/31291] Different (wrong?) behaviour using ffps when enabling optimizing 2007-03-21 7:13 [Bug c/31291] New: Different (wrong?) behaviour using ffps when enabling optimizing mail at sebastianbauer dot info @ 2007-03-21 7:14 ` mail at sebastianbauer dot info 2007-03-21 7:15 ` mail at sebastianbauer dot info 2007-03-21 9:59 ` rguenth at gcc dot gnu dot org 2 siblings, 0 replies; 4+ messages in thread From: mail at sebastianbauer dot info @ 2007-03-21 7:14 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from mail at sebastianbauer dot info 2007-03-21 07:14 ------- Created an attachment (id=13240) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13240&action=view) The simple test source. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31291 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/31291] Different (wrong?) behaviour using ffps when enabling optimizing 2007-03-21 7:13 [Bug c/31291] New: Different (wrong?) behaviour using ffps when enabling optimizing mail at sebastianbauer dot info 2007-03-21 7:14 ` [Bug c/31291] " mail at sebastianbauer dot info @ 2007-03-21 7:15 ` mail at sebastianbauer dot info 2007-03-21 9:59 ` rguenth at gcc dot gnu dot org 2 siblings, 0 replies; 4+ messages in thread From: mail at sebastianbauer dot info @ 2007-03-21 7:15 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from mail at sebastianbauer dot info 2007-03-21 07:15 ------- Created an attachment (id=13241) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13241&action=view) The output of the compiler invocation and the executable. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31291 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/31291] Different (wrong?) behaviour using ffps when enabling optimizing 2007-03-21 7:13 [Bug c/31291] New: Different (wrong?) behaviour using ffps when enabling optimizing mail at sebastianbauer dot info 2007-03-21 7:14 ` [Bug c/31291] " mail at sebastianbauer dot info 2007-03-21 7:15 ` mail at sebastianbauer dot info @ 2007-03-21 9:59 ` rguenth at gcc dot gnu dot org 2 siblings, 0 replies; 4+ messages in thread From: rguenth at gcc dot gnu dot org @ 2007-03-21 9:59 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from rguenth at gcc dot gnu dot org 2007-03-21 09:59 ------- You are violating C aliasing rules. Use a union or memcpy to access the fp value. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |INVALID Summary|Different (wrong?) behaviour|Different (wrong?) behaviour |using ffps when enabling |using ffps when enabling |optimizing |optimizing http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31291 ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2007-03-21 9:59 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2007-03-21 7:13 [Bug c/31291] New: Different (wrong?) behaviour using ffps when enabling optimizing mail at sebastianbauer dot info 2007-03-21 7:14 ` [Bug c/31291] " mail at sebastianbauer dot info 2007-03-21 7:15 ` mail at sebastianbauer dot info 2007-03-21 9:59 ` rguenth at gcc dot gnu dot org
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