Mail Archives: djgpp-workers/2000/03/22/04:20:28
On Mon, 20 Mar 2000, Hans-Bernhard Broeker wrote:
> > "Intel Architecture Software Developer's Manual", v.1 "Basic
> > Architecture" (I downloaded it from their site as 24319002.pdf, but that
> > was quite a while ago), Section 7.6, Table 7-18. The Result column only
> > mentions a real indefinite if neither of the operands is a NaN. Your
> > case appears to be covered by the third possible combination (two QNaNs),
> > whose result should be a QNaN, i.e. either with the sign bit reset or
> > with a mantissa that doesn't fit the real indefinite description.
>
> It's not just 'a QNaN'. You get 'the QNaN with the bigger significand'
> (i.e. mantissa), according to my book.
Yes, but in this case the mantissas were identical.
> Thinking about, this seems to imply
> that the sign bit of the QNaN with the (absolutely) bigger significand is
> just copied as-is.
How do you deduce that? The manual keeps suspicious silence about the
sign bit.
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