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* [Bug c++/40333] New: g++ does not align static variables properly @ 2009-06-03 21:22 gccsse at mailinator dot com 2009-06-03 21:26 ` [Bug c++/40333] " pinskia at gcc dot gnu dot org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: gccsse at mailinator dot com @ 2009-06-03 21:22 UTC (permalink / raw) To: gcc-bugs The following SSE2 code crashes because the non-static global variable breaks the alignment of the static data section. align.cpp: #include <emmintrin.h> int nonstatic_padding; static int static_padding[3]; static __attribute__((aligned(16))) __m128i sse_data; int main() { static_padding[0] = 1234; sse_data = _mm_set1_epi32(123); return 0; } The example uses SSE2 because that's how I discovered the bug and because it results in a nice crash, though I don't think it's essential at all. Results: - crashes (even when static_padding is removed) - no longer crashes when removing nonstatic_padding (even when static_padding is present) - no longer crashes when making sse_data non-static Tested with: g++-4 (GCC) 4.3.2 20080827 (beta) 2 and g++ (GCC) 3.4.4 (cygming special, gdc 0.12, using dmd 0.125) (I know they're a bit old, but Cygwin doesn't provide more recent binaries) If you rename the file to align.c gcc compiles it correctly and the program does not crash (gcc places static variables before non-static ones, unlike g++). -- Summary: g++ does not align static variables properly Product: gcc Version: 4.3.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: gccsse at mailinator dot com GCC build triplet: i686-pc-cygwin GCC host triplet: i686-pc-cygwin GCC target triplet: i686-pc-cygwin http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40333 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/40333] g++ does not align static variables properly 2009-06-03 21:22 [Bug c++/40333] New: g++ does not align static variables properly gccsse at mailinator dot com @ 2009-06-03 21:26 ` pinskia at gcc dot gnu dot org 2009-08-24 4:38 ` rogerdpack at gmail dot com 2009-08-24 6:15 ` dannysmith at users dot sourceforge dot net 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu dot org @ 2009-06-03 21:26 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from pinskia at gcc dot gnu dot org 2009-06-03 21:26 ------- *** This bug has been marked as a duplicate of 37216 *** -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |DUPLICATE http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40333 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/40333] g++ does not align static variables properly 2009-06-03 21:22 [Bug c++/40333] New: g++ does not align static variables properly gccsse at mailinator dot com 2009-06-03 21:26 ` [Bug c++/40333] " pinskia at gcc dot gnu dot org @ 2009-08-24 4:38 ` rogerdpack at gmail dot com 2009-08-24 6:15 ` dannysmith at users dot sourceforge dot net 2 siblings, 0 replies; 4+ messages in thread From: rogerdpack at gmail dot com @ 2009-08-24 4:38 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from rogerdpack at gmail dot com 2009-08-24 04:38 ------- (In reply to comment #0) > The following SSE2 code crashes because the non-static global variable breaks > the alignment of the static data section. Is this fixed if you use 4.5.0? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40333 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/40333] g++ does not align static variables properly 2009-06-03 21:22 [Bug c++/40333] New: g++ does not align static variables properly gccsse at mailinator dot com 2009-06-03 21:26 ` [Bug c++/40333] " pinskia at gcc dot gnu dot org 2009-08-24 4:38 ` rogerdpack at gmail dot com @ 2009-08-24 6:15 ` dannysmith at users dot sourceforge dot net 2 siblings, 0 replies; 4+ messages in thread From: dannysmith at users dot sourceforge dot net @ 2009-08-24 6:15 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from dannysmith at users dot sourceforge dot net 2009-08-24 06:15 ------- (In reply to comment #2) > (In reply to comment #0) > > The following SSE2 code crashes because the non-static global variable breaks > > the alignment of the static data section. > > Is this fixed if you use 4.5.0? > This is fixed with 4.5.0 and a recent binutils (Nick Clifton's patch to GAS was commuitted on 2008-09-03) Danny -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40333 ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2009-08-24 6:15 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-06-03 21:22 [Bug c++/40333] New: g++ does not align static variables properly gccsse at mailinator dot com 2009-06-03 21:26 ` [Bug c++/40333] " pinskia at gcc dot gnu dot org 2009-08-24 4:38 ` rogerdpack at gmail dot com 2009-08-24 6:15 ` dannysmith at users dot sourceforge dot net
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