This is the mail archive of the gcc-bugs@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[Bug rtl-optimization/45678] [4.4/4.5/4.6 Regression] crash on vector code with -m32 -msse



------- Comment #13 from rguenth at gcc dot gnu dot org  2010-09-16 13:39 -------
(In reply to comment #12)
> (In reply to comment #4)
> > Created an attachment (id=21809)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21809&action=view) [edit]
> > patch to fix "half STRICT_ALIGNMENT" targets memcpy folding
> > 
> > Might need this patch to fix as well.  i?86 / x86_64 isn't really
> > !STRICT_ALIGNMENT.
> > 
> 
> We need a HARD_ALIGNMENT which depends on type for x86.

With that patch the assignment generated from memcpy doesn't need more
that int alignment, but still cfgexpand.c sets DECL_ALIGN of the
decl to 128 so expand uses aligned instructions.

cfgexpand.c should not increase alignment and not set 'needs stack
alignment' then, based on your comment #10.  So this _is_ about
stack alignment (but maybe not exclusively).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45678


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]