Re: PATCH: PR target/46519: Missing vzeroupper

[Uros Bizjak <ubizjak@gmail.com>]

On Wed, Dec 29, 2010 at 4:32 PM, H.J. Lu <hjl.tools@gmail.com> wrote:

>> I think that due to these reasons, the patch should be committed to
>> SVN even in this development stage. Even if the algorithm is not
>> optimal, the patch demonstrably produces substantially better code.
>> This feature has no impact on generic code without -mvzeroupper /
>> -mavx switch, and since there are currently very few AVX users,
>> negligible overall impact.
>>
>>> gcc/
>>>
>>> 2010-12-18  H.J. Lu  <hongjiu.lu@intel.com>
>>>
>>>        PR target/46519
>>>        * config/i386/i386.c (block_info_def): Remove referenced, count
>>>        and rescanned.
>>>        (move_or_delete_vzeroupper_2): Updated.
>>>        (move_or_delete_vzeroupper_1): Rewritten to avoid recursive call.
>>>        (rescan_move_or_delete_vzeroupper): Removed.
>>>        (move_or_delete_vzeroupper): Repeat processing all basic blocks
>>>        until no basic block state is changed to used at exit.
>>>
>>> gcc/testsuite/
>>>
>>> 2010-12-18  H.J. Lu  <hongjiu.lu@intel.com>
>>>
>>>        PR target/46519
>>>        * gfortran.dg/pr46519-2.f90: New.
>>>
>>
>> The patch is OK, but please allow a day or two for RMs (CC'd) to
>> eventually comment.
>
> We will investigate LCM for 4.7.  In the meantime, here is  a small patch
> on top of the current one. If the upper 128bits are never changed in a basic
> block, we can skip it in the later passes.  OK for trunk together with the
> current patch?
>
> 2010-12-29  H.J. Lu  <hongjiu.lu@intel.com>
>
>        * config/i386/i386.c (upper_128bits_state): Update comments.
>        (block_info_def): Add unchanged.
>        (move_or_delete_vzeroupper_2): Short circuit if upper 128bits
>        are unchanged in the block.
>

OK, but please remove now redundant coments in

@@ -60,14 +60,17 @@ along with GCC; see the file COPYING3.  If not see
 enum upper_128bits_state
 {
   unknown = 0,		/* Unknown.  */
-  unused,		/* Not used or not referenced.  */
-  used			/* Used or referenced.  */
+  unused,		/* Not used.  */
+  used			/* Used.  */
 };

Thanks,
Uros.