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From: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Newsgroups: comp.lang.forth
Subject: Re: Floating point stack
Message-ID: <8028@tekgvs.LABS.TEK.COM>
Date: 30 Aug 90 15:16:58 GMT
References: <wmb@MITCH.ENG.SUN.COM> <9008281431.AA00691@ucbvax.Berkeley.EDU>
Reply-To: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 27


This is getting tiresome.

LMI Forths put floating point numbers on the parameter stack. When 
incorporating floating point operations into my Native Code Compiler,
I wanted separate stacks to take advantage of the additional performance
(speed, code size, and accuracy) of stack operations in the 80x87.
For compatibility I rewrote the existing LMI package to use the
coprocessor stack.

After changing the primitives, very little additional changes had to made.
It hardly affects good application code at all (by *good* I mean *readable*
and readable code does very little stack manipulation).

Hey folks, it's not that difficult to write code that works in both 
environments; what hurts portability is not having a standard for the
primitive functions!

So lets have a standard that lets this be an implementation detail, where
it belongs! If it makes sense for an 80x86/7 system to have separate stacks
and for a Forth chip system to have one stack, that's fine! Consider the
problems we have had in existing standards which specify division working
in ways other than the hardware, or wordsizes that don't match reality.

Tom Almy
toma@tekgvs.labs.tek.com
Standard Disclaimers Apply