Mail Archives: djgpp-workers/2000/03/20/12:12:57
On Mon, 20 Mar 2000, Hans-Bernhard Broeker wrote:
> > Not only because of this, but also because how Intel treats the real
> > indefinite. It is clear (to me) from that treatment that they use the
> > sign bit as a flag, to the effect that this NaN was produced by an
> > operation wher none of the operands was a NaN.
>
> The sign bit alone does not identify the 'real indefinite'. The mantissa
> is also fixed. So the 'flag', if any, would be the whole 64 bits of
> information, not just the sign bit.
Not really: if you flip the sign but leave the rest alone, the real
indefinite becomes a QNaN; you don't need to change the rest of the
bits.
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