[Gcl-devel] Re: [Maxima] Bugs in gcl cause maxima build failures

Greetings!

Raymond Toy <toy@rtp.ericsson.se> writes:

> >>>>> "Camm" == Camm Maguire <camm@enhanced.com> writes:
> 
>     Camm> I'd like to get it right.
> 
> 
>     >> I can help you get the right values, but I don't know how to tell gcl
>     >> to get the right values.
>     >> 
> 
>     Camm> Please do.  I can get gcl to report whatever we want here, but I don't
>     Camm> yet understand what is intended.  Your help as always most
>     Camm> appreciated!
> 
> Richard Fateman sent you the answer for single-float.  If I remember
> correctly, gcl only has double-float, so here is an answer appropriate
> for that:
> 
> * (integer-decode-float least-positive-normalized-double-float)
> 
> 4503599627370496
> -1074
> 1
> * (scale-float 4503599627370496d0 -1074)
> 
> 2.2250738585072014d-308
> 
> I also remember gcl being a bit sensitive to things on the very edge
> of the number range so that constant 45...96d0 might not be converted
> exactly right.
> 

OK, here is what I have:

>(setf r least-positive-normalized-single-float)

2.2250738585072014E-308

>(setf r least-positive-normalized-short-float)

1.175494S-38

>(setf r least-positive-normalized-double-float)

2.2250738585072014E-308

>(setf r least-positive-normalized-long-float)

2.2250738585072014E-308

>(integer-decode-float least-positive-normalized-double-float)

4503599627370496
-1074
1

>(integer-decode-float least-positive-normalized-short-float)

8388608
-149
1


So this looks right, given that gcl has 'single' being double, but
these are exactly the same as the unnormalized versions.  Should they
be different, and if so how?

Thanks again, 


> Ray
> 
> 

-- 
Camm Maguire			     			camm@enhanced.com
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