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Re: [RFA] expand from SSA form (1/2)


On Sun, Apr 26, 2009 at 10:47 PM, Michael Matz <matz@suse.de> wrote:
> Hi,
>
> On Sun, 26 Apr 2009, Richard Guenther wrote:
>
>> > into the var annotation (to be able to read it out again when the same
>> > basevar is seen for a different partition). ?But this whole info is
>> > strictly local to the above function, so it doesn't need to live in the
>> > annotation. ?I could very well implement this as an array indexed by
>> > DECL_UID. ?The UIDs shouldn't become exceptionally large, so that seems
>>
>> Hm. ?DECL_UIDs are sparse (and global), it would be a bad idea to index
>> an array with it.
>
> Those few 100k entries ... nobody will notice. ?Hmm, well, maybe someone
> does :-)
>
>> Is var_ann->common.aux already used by out-of-SSA?
>
> Oh joy. ?This field is unused by out-of-SSA. ?Which makes sense, as -
> drumroll - nothing (!) at all uses it (in the sense of deleting it doesn't
> break compile).
>
> I'd rather remove that field and the fields in the var annotation.

Indeed.  I'm testing a patch to remove the aux field.  The partial
transition to tuples (the hack going back to GENERIC for expansion)
also introduced two members, stmt and rn.  Fixing that partial
transition should shrink tree_ann_common_d further.

In the end we would like to get rid of tree annotations completely
of course.

Richard.


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