* SNaN & QNaN on mips
@ 2002-02-04 6:22 Zhang Fuxin
2002-02-04 6:54 ` H . J . Lu
2002-02-04 6:59 ` Kjeld Borch Egevang
0 siblings, 2 replies; 3+ messages in thread
From: Zhang Fuxin @ 2002-02-04 6:22 UTC (permalink / raw)
To: linux-mips@oss.sgi.com
hi,
Gcc (2.96 20000731,H.J.LU's rh port for mips) think 0x7fc00000 is QNaN and
optimize 0.0/0.0 as 0x7fc00000 for single precision ops,while for my cpu
(maybe most mips cpu) is a SNaN. R4k user's manual and "See Mips Run" both
say so.And experiments confirm this.
Should we correct it?
>
>Regards
> Zhang Fuxin
> fxzhang@ict.ac.cn
Regards
Zhang Fuxin
fxzhang@ict.ac.cn
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: SNaN & QNaN on mips
2002-02-04 6:22 SNaN & QNaN on mips Zhang Fuxin
@ 2002-02-04 6:54 ` H . J . Lu
2002-02-04 6:59 ` Kjeld Borch Egevang
1 sibling, 0 replies; 3+ messages in thread
From: H . J . Lu @ 2002-02-04 6:54 UTC (permalink / raw)
To: Zhang Fuxin; +Cc: linux-mips@oss.sgi.com
On Mon, Feb 04, 2002 at 02:22:48PM +0800, Zhang Fuxin wrote:
> hi,
>
> Gcc (2.96 20000731,H.J.LU's rh port for mips) think 0x7fc00000 is QNaN and
> optimize 0.0/0.0 as 0x7fc00000 for single precision ops,while for my cpu
> (maybe most mips cpu) is a SNaN. R4k user's manual and "See Mips Run" both
> say so.And experiments confirm this.
>
> Should we correct it?
Yes. Do you have a patch?
Thanks.
H.J.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: SNaN & QNaN on mips
2002-02-04 6:22 SNaN & QNaN on mips Zhang Fuxin
2002-02-04 6:54 ` H . J . Lu
@ 2002-02-04 6:59 ` Kjeld Borch Egevang
1 sibling, 0 replies; 3+ messages in thread
From: Kjeld Borch Egevang @ 2002-02-04 6:59 UTC (permalink / raw)
To: Zhang Fuxin; +Cc: linux-mips@oss.sgi.com
On Mon, 4 Feb 2002, Zhang Fuxin wrote:
> hi,
>
> Gcc (2.96 20000731,H.J.LU's rh port for mips) think 0x7fc00000 is QNaN and
> optimize 0.0/0.0 as 0x7fc00000 for single precision ops,while for my cpu
> (maybe most mips cpu) is a SNaN. R4k user's manual and "See Mips Run" both
> say so.And experiments confirm this.
MIPS interprets Signalling NaN's different than e.g. Intel. According to
IEEE754 it _is_ a matter of interpretation. 0x7fc00000 is an SNaN while
0x7fbfffff is an QNaN. It would be great if you could fix it.
/Kjeld
> Should we correct it?
>
> >
> >Regards
> > Zhang Fuxin
> > fxzhang@ict.ac.cn
>
> Regards
> Zhang Fuxin
> fxzhang@ict.ac.cn
>
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^ permalink raw reply [flat|nested] 3+ messages in thread
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