Re: [Qemu-devel] [6050] fp: add floatXX_is_infinity(), floatXX_is_neg(), floatXX_is_zero()

["Aurélien Jarno" <aurelien@aurel32.net>]

On Mon, Dec 15, 2008 at 06:48:27PM +0100, Andreas Färber wrote:
> Hi,
>
> Am 15.12.2008 um 18:14 schrieb Aurelien Jarno:
>
>> Revision: 6050
>>          http://svn.sv.gnu.org/viewvc/? 
>> view=rev&root=qemu&revision=6050
>> Author:   aurel32
>> Date:     2008-12-15 17:14:20 +0000 (Mon, 15 Dec 2008)
>>
>> Log Message:
>> -----------
>> fp: add floatXX_is_infinity(), floatXX_is_neg(), floatXX_is_zero()
>>
>> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
>
> Doesn't IEEE 754 have both a positive and a negative zero?
>
>> +INLINE float32 float32_is_neg(float32 a)
>> +{
>> +    return a < 0.0;
>> +}
>
> I would assume that 0.0 == -0.0 so this would not indicate a negative  
> zero as negative. Is that intended?
>

This is true, however I doubt it will make a difference given the use
of this function (for sure it doesn't make any difference given the
current use). I have fixed it for the sake of correctness, but the
resulting code is now probably slower.

-- 
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