------- Comment #16 from pinskia at gcc dot gnu dot org 2006-11-19 02:06
-------
(In reply to comment #15)
> Is the alignment requirement always applicable in all the cases, or just
> for gcc-3.4.6 ?
It segfaults for me with gcc-4.1.2.
>
> Remember, in this case gcc-4.1.1 produces code which doesn't segfault.
That could be because malloc/stack locations just happen to be 16byte aligned
>
> Is it that gcc-4.1.1 optimizes out the failing line ?
No.
> Is it that gcc-4.1.1 falsely aligns the memory location in question ?
Well it can be 8byte aligned and accidently also 16byte aligned (which does
happen every once in a while).
> Is it that gcc-4.1.1 uses misaligned load into SSE registers by default ?
No because I could reproduce the failure in 4.1.2
>
> Is there any page in gcc manual clearly saying:
>
> "align your data properly or your program will segfault"
>
> ?
>
> I am specifically interested in the "or your program will segfault" part ?
This is call debugging your program. Also you really should read web pages
about SSE programming because it seems like you don't understand how to use.
Also using mode with vector mode is deprecated and you should be using
vector_size instead.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29818
