Re: [PATCH 3/8] rs6000: Convert <x> built-in constraints to <x,y> form

[Bill Schmidt <wschmidt@linux.ibm.com>]

On 1/31/22 11:28 AM, Segher Boessenkool wrote:
> On Mon, Jan 31, 2022 at 11:21:32AM -0600, Bill Schmidt wrote:
>> On 1/28/22 5:24 PM, Segher Boessenkool wrote:
>>> On Fri, Jan 28, 2022 at 11:50:21AM -0600, Bill Schmidt wrote:
>>>> When introducing the new built-in support, I tried to match as many
>>>> existing error messages as possible.  One common form was "argument X must
>>>> be a Y-bit unsigned literal".  Another was "argument X must be a literal
>>>> between X' and  Y', inclusive".  During reviews, Segher requested that I
>>>> eventually convert all messages of the first form into the second form for
>>>> consistency.  That's what this patch does, replacing all <x>-form
>>>> constraints (first form) with <x,y>-form constraints (second form).
>>> Well, I asked for the error messages to be clearer and more consistent
>>> like that.  I don't think changing our source code like this is an
>>> improvement (*we* know what a 5-bit signed number is).  Do you think
>>> after your patch it is clearer and we will make fewer errors?
>> No, I don't think the patch is a particular improvement.  It sounds like
>> I may have misinterpreted what you were looking for here.  Please let me
>> know what I might do differently.
>>
>> For example, if we leave the <x> format in place in the source, I could
>> change the error messages that we produce to calculate the minimum and
>> maximum allowed values.  Then we'd still have the changes to the test
>> cases, but fewer changes to the source.  Thoughts?
> That is exactly what I asked for, and what I still think is the best
> option.  I haven't tried it out though, so there may be arguments
> against this :-)

Thanks for the clarification!  I'll make a run at it.

Bill

>
> Segher