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Re: [RFC PATCH, i386]: Rewrite pop patterns to use POST_INC memory operands
On Mon, Aug 30, 2010 at 8:04 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Mon, Aug 30, 2010 at 08:00:50PM +0200, Uros Bizjak wrote:
>> > I must say I'm very surprised if the patch works reliably, there are many
>> > #ifdef AUTO_INC_DEC guarded hunks and not all of them are related only
>> > to automatic inc/dec additions, but just whether the code should look for
>> > PRE/POST_INC/DEC/MODIFY in the IL. ?E.g. cleanup_auto_inc_dec
>> > in the combiner.c to give some example.
>> > And, cselib does very poor job with inc/dec addressing currently (except for
>> > var-tracking which removes inc/dec addressing from the IL before feeding it
>> > into cselib).
>>
>> i386 was already AUTO_INC_DEC target due to pre_decrement push insn,
>> The patch just balances the machine description by re-defining pop in
>> terms of post_increment.
>
> No, i386 is not AUTO_INC_DEC target, as it doesn't define the necessary
> macros (any of HAVE_{PRE,POST}_{INCREMENT,DECREMENT,MODIFY}).
Ah, you are right.... I was under impression that build system sets
these defines automatically.
In this case, the patch is only a nice cleanup.
Uros.