On 20 February 2008 16:34, Jeff Law wrote:
> Paolo Bonzini wrote:
>>
>>>> Is there any particular function or pass that should be dealing with
>>>> IOR rx,0 - that I could trace thru and figure out why it does not
>>>> like it (or never gets there)?
>>> I would be looking in combine and simplify-rtx (which is called by
>>> combine). If your splitter triggers after combine, then I'm not
>>> immediately sure where to look -- I'm not offhand aware of a pass
>>> after combine which would call into simplify-rtx to perform this
>>> optimization.
>>
>> Me neither, but this
>> could be a place where it is done.
>>
> I'm still looking at this, but I don't see much of a chance to attack
> this specific problem in the combiner.
>
> I'm thinking this is going to need to be attacked along one of three
> lines:
>
In the meantime, Andy's quickest and safest option is probably to use
peepholes to eliminate the redundant insns altogether, rather than having to
replace them with nops.
cheers,
DaveK
--
Can't think of a witty .sigline today....
