[tree-ssa] Alias analysis speedups

[Daniel Berlin]

On Friday, February 21, 2003, at 03:03  PM, Toon Moene wrote:

> law@redhat.com wrote:
>
>> In message <1045844562.8671.18.camel@shadowfax>, Diego Novillo writes:
>
>>  >Mixed blessing in this case.  Better alias info may lead to longer
>>  >compile times and memory problems.  Hence our PHI pruning 
>> heuristics.
>
>> Yes, but those are very extreme cases.
>
> "Elk nadeel hep se foordeel" :-)
>
> What would this mean for an extremely non-aliasing language like 
> Fortran  ?
>

Couldn't tell you experimentally if he wanted to, since Fortran doesn't 
create GIMPLE trees.
But, in general, it wouldn't be a problem for an extreme non-aliasing 
language, since there would generally be *no* alias sets (because of no 
aliases) the sets, not a large number of *small* sets, as you end up 
with in C.
Even if you had some aliases, it would still be a small number of sets.
In C, we have a large number of things that alias other things, but a 
small number of things they each alias.
In fortran, you'd have a small number of things that alias other 
things, and a small number of things they each alias.

> Inquiring minds want to know ...
>
> -- 
> Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
> Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
> Maintainer, GNU Fortran 77: http://gcc.gnu.org/onlinedocs/g77_news.html
> GNU Fortran 95: http://gcc-g95.sourceforge.net/ (under construction)
>