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From: Florian Weimer <fw@deneb.enyo.de>
Subject: Re: What is the warning about builtin-function on gcc-4.6.0 ?
Date: Sat, 26 Mar 2011 18:02:01 +0100
Date: 2011-03-26T18:02:01+01:00	[thread overview]
Message-ID: <8762r5hl2u.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: m28vw1g7wf.fsf@pushface.org

* Simon Wright:

> Florian Weimer <fw@deneb.enyo.de> writes:
>
>> * Simon Wright:
>>
>>> ytomino <aghia05@gmail.com> writes:
>>>
>>>> nn...then, there are no function to take infinity and NaN...
>>>
>>> 'Valid should do the trick.
>>>
>>>    FP_Value := 1.0 / 0.0;
>>>    if FP_Value'Valid then
>>>       --  it won't be
>>
>> This is a compiler bug.
>
> I don't understand what you mean.

The standard requires that FP_Value'Valid is true.

> If the compiler doesn't raise an exception on division by zero (it's
> allowed not to, and GNAT doesn't) it will (in this case) set the result
> to +Inf, and 'Valid will return False.

My understanding is that an implementation must either raise
Constraint_Error, or the evaluation of an expression must result in a
valid value.



  reply	other threads:[~2011-03-26 17:02 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-26  6:32 What is the warning about builtin-function on gcc-4.6.0 ? ytomino
2011-03-26  8:45 ` Florian Weimer
2011-03-26  9:13   ` ytomino
2011-03-26  9:43     ` Florian Weimer
2011-03-26 10:07       ` ytomino
2011-03-26 10:24         ` Florian Weimer
2011-03-26 15:14           ` Dmitry A. Kazakov
2011-03-26 21:36             ` ytomino
2011-03-27  9:50               ` Dmitry A. Kazakov
2011-03-26 14:50         ` Simon Wright
2011-03-26 15:50           ` Florian Weimer
2011-03-26 16:32             ` Simon Wright
2011-03-26 17:02               ` Florian Weimer [this message]
2011-03-26 17:48                 ` Simon Wright
2011-03-26 18:48                   ` Florian Weimer
2011-03-27  2:08                 ` Randy Brukardt
2011-03-27  8:37                   ` Florian Weimer
2011-03-27 16:41                     ` Robert A Duff
2011-03-27 17:21                       ` Florian Weimer
2011-03-27 17:56                         ` Robert A Duff
2011-03-27 16:51                     ` Robert A Duff
2011-03-27 17:05                       ` Florian Weimer
2011-03-27 17:14                         ` Robert A Duff
2011-03-29  2:20                           ` Randy Brukardt
2011-03-29 18:35                             ` Robert A Duff
2011-03-29 23:35                               ` Randy Brukardt
2011-03-30  1:02                               ` Adam Beneschan
2011-03-30 12:57                                 ` Robert A Duff
2011-03-30 14:41                                   ` Adam Beneschan
2011-03-30 18:39                                     ` Robert A Duff
2011-03-30 19:28                                   ` Randy Brukardt
2011-03-26 21:58       ` ytomino
2011-03-26 22:00         ` Florian Weimer
2011-03-26 22:22 ` anon
2011-03-26 22:36   ` ytomino
2011-03-27 12:00     ` anon
2011-03-27 18:50       ` ytomino
2011-03-27 23:35         ` anon
2011-03-27 23:42         ` anon
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