[Bug tree-optimization/64590] Firefox 34 triggers GCC AVX bug (segfault: XPCCallContext::GetJSContext (this=0xfffc7fffe3e23980))

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64590

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
That most likely means a failed assertion implemented on the mozilla side as
store to NULL pointer followed to __builtin_trap () just in case.
Anyway, that doesn't look like a reason for the -march=nehalem vs.
-march=sandybridge differences.  If that really turns a working binary into
non-working, perhaps try to bisect between -march=nehalem -O3 and
-march=sandybridge -O3 (forget about -floop-interchange -floop-strip-mine
-floop-block everywhere) built *.o files, until you find the problematic one. 
Then using __attribute__((target ("march=sandybridge"))) in -march=nehalem
compiled object (or vice versa) you could try to bisect between different
routines to find out where the problem is.