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

[fragabr at gmail dot com]

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

            Bug ID: 64590
           Summary: Firefox 34 triggers GCC AVX bug (segfault:
                    XPCCallContext::GetJSContext
                    (this=0xfffc7fffe3e23980))
           Product: gcc
           Version: 4.9.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fragabr at gmail dot com

I reported this bug at Firefox bugzilla:

https://bugzilla.mozilla.org/show_bug.cgi?id=1117023

and the developers told me this is a GCC bug: "This very much sounds like a bug
in gcc's vectorization using avx".

So could you take a look? I compiled with:

-march=native -O3 -pipe -floop-interchange -floop-strip-mine -floop-block

The workaround is to compile with -march=nehalem (to avoid AVX optimization for
Sandybridge).

Thanks.