------- Additional Comments From fjahanian at apple dot com 2004-12-18 01:46
-------
And this is the patch that I had in mind. Can this break ABI compatibily? My
limited testing shows
that it does not.
Index: rs6000.c
===============================================================
====
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v
retrieving revision 1.332.2.46.2.84
diff -c -p -r1.332.2.46.2.84 rs6000.c
*** rs6000.c 16 Dec 2004 03:23:30 -0000 1.332.2.46.2.84
--- rs6000.c 18 Dec 2004 01:44:28 -0000
*************** function_arg_boundary (enum machine_mode
*** 5190,5195 ****
--- 5190,5201 ----
|| (type && TREE_CODE (type) == VECTOR_TYPE
&& int_size_in_bytes (type) >= 16))
return 128;
+ else if (DEFAULT_ABI == ABI_DARWIN && mode == BLKmode
+ && TYPE_ALIGN (type) >= 128)
+ {
+ TYPE_ALIGN (type) = PARM_BOUNDARY;
+ return PARM_BOUNDARY;
+ }
else
return PARM_BOUNDARY;
}
(In reply to comment #5)
> Followin patch fixes the alignment problem. But it cannot be applied because
> it breaks ABI
> compatibilty.
>
> A possible solution is to relax alignment of the type in question (with
> alignment of 128) to that of the
> PARM_BOUNDARY (32). This will not (should not ?) break the ABI compatibility
> (because it is currently
> on PARM_BOUNDARY). But it will prevent vector code to be generated (which is
> cause of the abort).
> Comments are most welcome.
>
>
> Index: rs6000.c
>
===============================================================
> ====
> RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v
> retrieving revision 1.332.2.46.2.84
> diff -c -p -r1.332.2.46.2.84 rs6000.c
> *** rs6000.c 16 Dec 2004 03:23:30 -0000 1.332.2.46.2.84
> --- rs6000.c 18 Dec 2004 00:20:54 -0000
> *************** function_arg_boundary (enum machine_mode
> *** 5190,5195 ****
> --- 5190,5197 ----
> || (type && TREE_CODE (type) == VECTOR_TYPE
> && int_size_in_bytes (type) >= 16))
> return 128;
> + else if (DEFAULT_ABI == ABI_DARWIN && mode == BLKmode)
> + return MAX (TYPE_ALIGN (type), PARM_BOUNDARY);
> else
> return PARM_BOUNDARY;
> }
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18916
