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From: peter <peter.noreply@tin.it>
Newsgroups: comp.lang.forth
Subject: Re: Getting the exponent of an x87 float
Date: Wed, 19 Aug 2026 09:58:09 +0200
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On Wed, 19 Aug 2026 17:14:28 +1000
dxf <dxforth@gmail.com> wrote:

> On 19/08/2026 1:48 pm, dxf wrote:
> > ...
> > In my case
> > I ... used REPRESENT to calculate the exponent of
> > 1E-3.
> 
> Hmm, testing shows REPRESENT to be way worse than an unpatched FLOG
> for grabbing the exponent.  If the following fails I give up!
> 
>   : (G.) ( F: r -- ) ( n -- c-addr u )
>     >R  FDUP FABS  FDUP 1E-3 F< 0= >R  1E6 F<  R> AND
>     R> SWAP IF  (F.)  ELSE  (FS.)  THEN ;
> 

What does the n do. It looks like it just remains on the stack.

I have 

: E. ( F: r -- )   
    fdup (e.)  dup >r
    (es.)  dup r> < if 2swap then 2drop type space ;

to decide what output function to use. It works as (f.) (fs.)
uses a circular buffer with 16 slots. (e.) (es.) are variants
of (f.) (fs.)

BR
Peter