RFD: language hooks in GIMPLE / lang_flag?

[Richard Guenther]

On 7/15/06, Richard Kenner <kenner@vlsi1.ultra.nyu.edu> wrote:
> > OK.  But, GIMPLE is also supposed to be type-safe, so I wouldn't think
> > that "int = long" would be well-formed gimple.
>
> ... or we *could* define it that way.
>
> My point is just that whatever type "compatibility" might mean at the
> GIMPLE level, it should just be a function of whether the types will produce
> different code, not something at the language level.  The qustion of what
> we use the compatible types test for is different.  I wasn't suggesting
> (at this point at least!) that it be changed, but didn't research exactly
> when it's used either.

For most parts of the middle-end treating type compatibility as equivalence
of machine modes (for basic types, that is) should be ok.  Of course to not
lose alias information it needs to be attached to the proper objects (decls
and memory references) by the frontends and propagated accordingly.

Richard.