Re: Patch: {tree-ssa] Fixes re multiple type nodes from IMA

[Richard Henderson <rth at redhat dot com>]

On Wed, Mar 10, 2004 at 05:49:50PM -0800, Dale Johannesen wrote:
> + /* This compares two types for equivalence ("compatible" in C-based languages).
> +    This routine should only return 1 if it is sure.  It should not be used
> +    in contexts where erroneously returning 0 causes problems.  */
> + 
> + int
> + lhd_types_eq_p (tree x, tree y)
> + {
> +   return x == y;
> + }

I'd prefer "compatible" in the function name as well for emphasis.
I think you should move the TYPE_MAIN_VARIANT bit into the hook;
that'll clean up most users:

> !   if (!(*lang_hooks.types_eq_p)(TYPE_MAIN_VARIANT(orig_type), 
> ! 				TYPE_MAIN_VARIANT(elt_type)))

    if (lang_hooks.types_eq_p (orig_type, elt_type))

No need for (*foo) either; we're C90 now.

> +       /* Make sure the FIELD_DECL is actually a field in the type on
> + 	 the lhs.  In cases with IMA it is possible that it came
> + 	 from another, equivalent type at this point.  We have
> + 	 already checked the equivalence in this case.
> + 	 For unions, we must match on name; do this for structs
> + 	 also for simplicity.  */

Some fields don't have names.  This is particularly common with
compiler-generated structures.  I think I'd feel better if you
matched field type and offset.



r~