Re: [PATCH] Add support for floating point endpoints to frange.

[Toon Moene <toon@moene.org>]

On 8/29/22 16:36, Aldy Hernandez wrote:

> On Mon, Aug 29, 2022 at 4:30 PM Toon Moene <toon@moene.org> wrote:
>>
>> On 8/29/22 16:15, Aldy Hernandez wrote:
>>
>>> But even with -ffinite-math-only, is there any benefit to propagating
>>> a known NAN?  For example:
>>
>> The original intent (in 2002) for the option -ffinite-math-only was for
>> the optimizers to ignore all the various exceptions to common
>> optimizations because they might not work correctly when presented with
>> a NaN or an Inf.
>>
>> I do not know what the effect for floating point range information would
>> be - offhand.
>>
>> But in the *spirit* of this option would be to ignore that the range
>> [5.0, 5.0] would "also" contain NaN, for instance.
> 
> Hmm, this is somewhat similar to what Jakub suggested.  Perhaps we
> could categorically set !NAN for !HONOR_NANS at frange construction
> time?
> 
> For reference:
> bool
> HONOR_NANS (machine_mode m)
> {
>    return MODE_HAS_NANS (m) && !flag_finite_math_only;
> }
> 
> Thanks.
> Aldy
> 

Yep, I think that would do it.

Thanks,

-- 
Toon Moene - e-mail: toon@moene.org - phone: +31 346 214290
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