On 02/26/2018 02:09 PM, Richard Sandiford wrote:
> Martin Sebor <mse...@gmail.com> writes:
>> On 02/26/2018 12:45 PM, Richard Sandiford wrote:
>>> Martin Sebor <mse...@gmail.com> writes:
>>>> Richard,
>>>>
>>>> If you agree, I'd like to update the conversion section of
>>>> the poly_int manual to make the conversion to make it clearer
>>>> that the to_constant() function can be used even with class
>>>> types like offset_int besides scalars.
>>>>
>>>> Also, when testing this I also tried converting poly64_int
>>>> into wide_int but that doesn't work. Is there a way to do
>>>> that?
>>>
>>> Not in one go, because you have to specify the intended precision
>>> of the wide_int when constructing it from something like HOST_WIDE_INT.
>>> (That's deliberate.)
>>>
>>>>
>>>> Thanks
>>>> Martin
>>>>
>>>> gcc/ChangeLog:
>>>>
>>>> * doc/poly-int.texi (is_constant): Expand.
>>>>
>>>> Index: gcc/doc/poly-int.texi
>>>> ===================================================================
>>>> --- gcc/doc/poly-int.texi (revision 258004)
>>>> +++ gcc/doc/poly-int.texi (working copy)
>>>> @@ -836,9 +836,24 @@ Return true if @code{poly_int} @var{value} is a co
>>>>
>>>> @item @var{value}.is_constant (&@var{c1})
>>>> Return true if @code{poly_int} @var{value} is a compile-time constant,
>>>> -storing it in @var{c1} if so. @var{c1} must be able to hold all
>>>> -constant values of @var{value} without loss of precision.
>>>> +storing it in @var{c1} if so. @var{c1} may be a scalar or a wide int
>>>> +class type capable of holding all constant values of @var{value} without
>>>
>>> Not sure about "a scalar or a wide int", since that implies that wide ints
>>> aren't scalar. Even more pedantic, sorry, but c1 is an object rather than
>>> a type.
>>>
>>> At a higher level, I'm a bit nervous about singling this out as a special
>>> case, since all the poly_int stuff allows HOST_WIDE_INT, offset_int and
>>> wide_int to be combined in the (hopefully) natural way. E.g. you can
>>> add offset_ints to poly_int64s, assign HOST_WIDE_INTs to poly_offset_ints,
>>> and so on.
>>>
>>> But if we do keep it like this, how about:
>>>
>>> @var{c1} must be some form of integer object that can hold all constant
>>> values of @var{value} without loss of precision; it can be either a normal
>>> C++ integer or a wide-int class like @code{offset_int}.
>>>
>>> ?
>>
>> Sure. Attached is an update with your change.
>
> LGTM (but I can't approve).
That, IMHO, is a technicality :-) You know these bits better than
anyone. So if you're OK with them, that's good enough for me :-)
Rubber-stamped for the trunk.
jeff
