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From: "Dave Korn" <dave DOT korn AT artimi DOT com>
To: <cygwin AT cygwin DOT com>
Subject: RE: SV: Bug in printf ?
Date: Wed, 6 Jul 2005 10:29:38 +0100
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----Original Message----
>From: Lev Bishop
>Sent: 06 July 2005 09:15

> On 06/07/05, Lev Bishop wrote:
>> 4) I have no idea what mingw is doing, but it's different to the
>> above. Gcc constructs the same double precision constants as on cygwin
>> but strtod() is different and seems to have less precision, and
>> printf() seems to work with about 16 digits precision. At a glance I'd
>> say it rounds to zero, with exactly the precision of
> ... the precision of a raw double.
> 
> Ie, it looks like the cygwin build works slightly nicer than mingw
> with plenty of extra precision for conversions to and from decimal,
> and round-to-even for runtime conversions, which is a good thing.


  Thanks a great deal for looking at this; I'm not any kind of an FP expert,
I just have a grasp of the basics.  I've tried the testcase on an RH system
and yes, glibc and newlib agree here.  What mingw does is simple: it calls
M$'s implementation in the msvcrt library, so blame the beast of redmond for
the technically-incorrect-yet-reasonable-seeming behaviour.


    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....


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