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Re: gcc compile time support for assumptions
Andrew Haley <aph@redhat.com> writes:
> Ian Lance Taylor writes:
> > Abramo Bagnara <abramobagnara@tin.it> writes:
> >
> > > I'd like to know if gcc has implemented some generic way to help
> > > optimizer job by allowing programmers to specify assumptions (or
> > > constraints).
> >
> > The answer is no, there is nothing quite like you describe.
> >
> > But I think it would be a good idea.
>
> Something like this would greatly improve the code generation quality
> of gcj. There are a great many assertions that I could pass to VRP
> and the optimizers: this is invariant, this is less than that, and so
> on.
Well, internally, we do have ASSERT_EXPR. It would probably take a
little work to permit the frontends to generate it, but the optimizers
should understand it.
Ian