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From: koopman@a.gp.cs.cmu.edu (Philip Koopman)
Newsgroups: comp.lang.forth
Subject: Re: Floating point stack
Summary: clarification of a minor point
Message-ID: <10346@pt.cs.cmu.edu>
Date: 29 Aug 90 18:38:29 GMT
References: <wmb@MITCH.ENG.SUN.COM> <9008281431.AA00691@ucbvax.Berkeley.EDU> <0XI5RNG@xds13.ferranti.com>
Organization: Carnegie-Mellon University, CS/RI
Lines: 24

In article <0XI5RNG@xds13.ferranti.com>, peter@ficc.ferranti.com (Peter da Silva) writes:
> In article <10340@pt.cs.cmu.edu> koopman@a.gp.cs.cmu.edu (Philip Koopman) writes:
> > 4) One motivator for separate stacks is that 16-bit integers are not
> >  the same size as 32-bit reals.  On 32-bit hardware, this problem
> >  goes away: single and double precision for reals and ints are the same size.
> 
> Except for 64-bit reals (AKA double precision), which bring the whole thing
> back again. (If you say you don't need DP, I'll believe you... but you're
> not the whole world).

What I meant was  single int, single float = 32 bits
                  double int, double float = 64 bits
 DUP = FDUP
DDUP = FDDUP   (or, 2DUP = F2DUP, or whatever...)

So, double reals are no worse than double integers (and, in fact,
 the data type doesn't really matter much for stack manipulations any more).
Of course, this is only for 32 bit machines...

  Phil Koopman                koopman@greyhound.ece.cmu.edu   Arpanet
  2525A Wexford Run Rd.
  Wexford, PA  15090
Senior scientist at Harris Semiconductor, and adjunct professor at CMU.
I don't speak for them, and they don't speak for me.