Re: [PATCH] handle pathological anti-ranges in gimple_fold_builtin_memory_op (PR 81908)

[Martin Sebor <msebor at gmail dot com>]

> Just a stylistic thing, but since the only use of "wone" is in
> the eq_p, it'd be simpler just to use "1".  Also, the maximum
> value is better calculated as "wi::max_value (prec, SIGNED)".  So:
>
>   /* Compute the value of SSIZE_MAX, the largest positive value that
>      can be stored in ssize_t, the signed counterpart of size_t .  */
>   wide_int ssize_max = wi::max_value (prec, SIGNED);
>
>   return wi::eq_p (min, 1) && wi::geu_p (max, ssize_max);

Thanks, I didn't know about the implicit conversion or the max_value
API.  I'll remember to use them the next time.

FWIW, going slightly off topic, and while I'm sure it's a matter
of getting used to the design, I can't say I find the wide_int
classes exactly intuitive.  It seems that the most natural way
to write the return statement in C++ is:

  return min == 1 && max >= ssize_max;

The first subexpression is accepted but the second one doesn't even
compile.  If it did, it would treat the operands as signed which
isn't what I need here.  One still has to resort to the clunky
predicate for it:

  return min == 1 && wi::geu_p (max, ssize_max);

It also doesn't help that the names of the predicates don't follow
the same convention as those that operate on trees (e.g., eq_p vs
tree_int_cst_equal).

Unless there's some inherent limitation that makes it impossible
to use the class the way I would like it might be worth investing
some time into making it more user-friendly.

Martin