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* [Bug c++/48659] New: Segmentation fault when using openMP and SSE @ 2011-04-18 6:59 npozar at quick dot cz 2011-04-18 12:22 ` [Bug c++/48659] " rguenth at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: npozar at quick dot cz @ 2011-04-18 6:59 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48659 Summary: Segmentation fault when using openMP and SSE Product: gcc Version: 4.5.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: npozar@quick.cz Created attachment 24026 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24026 A code snippet that reproduces the error g++ tries to save an xmm register using MOVAPD (SSE instruction) to the stack when switching between working chunks during openMP multithreading. This obviously causes a random segmentation fault when the stack pointer happens not be aligned to a 16-byte boundary. Please see the attached code. I compile it with g++ 4.5.2 (I'm using MinGW) and flags -O3 -msse3 -fopenmp. It is important that the optimization is on and the compiler tries to save the xmm register containing the constant zero between working chunks. This is the instruction that causes the segmentation fault if ebp-0x48 is not divisible by 0x10: 0040143a: movapd %xmm1,-0x48(%ebp) // right here 0040143f: call 0x4014bc <GOMP_loop_dynamic_next> PS. I have to admit that I'm completely new to GCC, openMP or SSE (I just learned about openMP today and I've playing with them for a couple hours only), so I might be just doing something really stupid. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/48659] Segmentation fault when using openMP and SSE 2011-04-18 6:59 [Bug c++/48659] New: Segmentation fault when using openMP and SSE npozar at quick dot cz @ 2011-04-18 12:22 ` rguenth at gcc dot gnu.org 2013-01-26 14:04 ` [Bug target/48659] " redi at gcc dot gnu.org 2013-01-28 11:53 ` daniel.f.starke at freenet dot de 2 siblings, 0 replies; 4+ messages in thread From: rguenth at gcc dot gnu.org @ 2011-04-18 12:22 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48659 --- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-04-18 12:17:12 UTC --- On linux we assume a 16 byte aligned stack for threads, so this might hint at some MinGW specific issue either in our OMP runtime or with windows thread handling. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/48659] Segmentation fault when using openMP and SSE 2011-04-18 6:59 [Bug c++/48659] New: Segmentation fault when using openMP and SSE npozar at quick dot cz 2011-04-18 12:22 ` [Bug c++/48659] " rguenth at gcc dot gnu.org @ 2013-01-26 14:04 ` redi at gcc dot gnu.org 2013-01-28 11:53 ` daniel.f.starke at freenet dot de 2 siblings, 0 replies; 4+ messages in thread From: redi at gcc dot gnu.org @ 2013-01-26 14:04 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48659 Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |ktietz at gcc dot gnu.org --- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-01-26 14:03:44 UTC --- Kai, is this reproducable with current releases, and can you confirm Richard's suggestion about threads not having 16-byte aligned stacks? ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/48659] Segmentation fault when using openMP and SSE 2011-04-18 6:59 [Bug c++/48659] New: Segmentation fault when using openMP and SSE npozar at quick dot cz 2011-04-18 12:22 ` [Bug c++/48659] " rguenth at gcc dot gnu.org 2013-01-26 14:04 ` [Bug target/48659] " redi at gcc dot gnu.org @ 2013-01-28 11:53 ` daniel.f.starke at freenet dot de 2 siblings, 0 replies; 4+ messages in thread From: daniel.f.starke at freenet dot de @ 2013-01-28 11:53 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48659 --- Comment #3 from Daniel Starke <daniel.f.starke at freenet dot de> 2013-01-28 11:53:14 UTC --- I can confirm this bug for gcc 4.7.2 mingw64. The -mstackrealign command-line flag can be used as workaround as described on http://stackoverflow.com/questions/6716654/segmentation-fault-using-openmp-and-sse until this bug is properly patched. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-01-28 11:53 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2011-04-18 6:59 [Bug c++/48659] New: Segmentation fault when using openMP and SSE npozar at quick dot cz 2011-04-18 12:22 ` [Bug c++/48659] " rguenth at gcc dot gnu.org 2013-01-26 14:04 ` [Bug target/48659] " redi at gcc dot gnu.org 2013-01-28 11:53 ` daniel.f.starke at freenet dot de
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