> +/* Return true if DECL_ARGUMENT types are valid to be merged. */
Perhaps bettter as
Perform additional check needed to match types function parameters that are
used. Unlike for normal parameters it matters if type is TYPE_RESTRICT and we
make an assumption that REFERENCE_TYPE parameters are always non-NULL.
> +
> +bool
> +sem_function::compatible_parm_types_p ()
> +{
> + tree parm1, parm2;
> + unsigned i = 0;
> +
> + for (parm1 = DECL_ARGUMENTS (decl),
> + parm2 = DECL_ARGUMENTS (m_compared_func->decl);
> + parm1 && parm2;
> + parm1 = DECL_CHAIN (parm1), parm2 = DECL_CHAIN (parm2), i++)
I think this is still not right. What you wan to to do is to have
1) comparible_parm_types_p (t1,t2, index) that returns true if T1 and T2 are
matching with checks bellow:
> + {
> + if (!param_used_p (i))
> + continue;
> +
> + if (POINTER_TYPE_P (parm1)
> + && (TYPE_RESTRICT (parm1) != TYPE_RESTRICT (parm2)))
> + return return_false_with_msg ("argument restrict flag mismatch");
> + /* nonnull_arg_p implies non-zero range to REFERENCE types. */
> + if (POINTER_TYPE_P (parm1)
> + && TREE_CODE (parm1) != TREE_CODE (parm2)
> + && opt_for_fn (decl, flag_delete_null_pointer_checks))
> + return return_false_with_msg ("pointer wrt reference mismatch");
> + }
withtout actually walking the chain.
2) make equals_wpa to walk TYPE_ARG_TYPES of the function type and match them.
This is because DECL_ARGUMENTS are part of function body and before you
read it into memory, these are NULL
Walking DECL_ARGUMENTS here may cause ipa-icf to give up in case one body is
read (and thus have some arguments) and other is not.
3) make equals_private walk DECL_ARGUMENTS and match them
(well at the time you populate the map.)
You probalby can skip matching PARM_DECLS that are !parm_used_p (i)
for anything else than types_compatible_p.
We only care they are passed the same way by ABI. Everything else is not
relevant.
Honza
