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Re: NaN/Inf fix for ECPG

From: Rémi Zara <remi_zara(at)mac(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Boszormenyi Zoltan <zb(at)cybertec(dot)at>, Michael Meskes <meskes(at)postgresql(dot)org>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: NaN/Inf fix for ECPG
Date: 2010-02-27 17:18:10
Message-ID: B3A3A907-830C-49FA-BB5B-D2DE18934603@mac.com (view raw or flat)
Thread:
Lists: pgsql-hackers
Le 27 févr. 2010 à 17:57, Tom Lane a écrit :

> =?iso-8859-1?Q?R=E9mi_Zara?= <remi_zara(at)mac(dot)com> writes:
>> Le 26 févr. 2010 à 17:11, Tom Lane a écrit :
>>> Hmm.  So what do you get from
>>> SELECT 'nan'::numeric::float8;
> 
>> regression=# select 'nan'::numeric::float8;
>>  float8  
>> ----------
>> Infinity
>> (1 row)
> 
>> So it is indeed the same behavior.
> 
> Yeah.  So what it boils down to is that the platform has a NAN constant
> but casting it to double produces the wrong thing.  There's no doubt
> that that's a bug in the floating-point support.  You did say you'd
> submitted it to the NetBSD folk right?
> 

I submitted it.

> BTW, what about the float4 case, 'nan'::numeric::float4 ?

That works OK.

> 
>> Maybe that should be added to the regression tests.
> 
> Perhaps.  A lot of this stuff was never stress-tested in the past
> because when it was put in, it was a crap shoot whether NaN (or Inf)
> really worked on most platforms.  Our attitude was "if it works for you,
> great, but we're not going to sweat about it if it doesn't".  I'm not
> sure whether full IEEE float support has gotten sufficiently universal
> to justify expecting more.  I guess we could try it and see how many
> other buildfarm members fail.
> 
>> So what's the best way to workaround the bug in NetBSD/mips ?
> 
> I don't think it's our bug to fix.
> 

It would mean retiring pika until/if the bug is fixed... :-(

Regards,

Rémi Zara

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