Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!munnari.oz.au!csc!ccadfa!csadfa!stephens
From: stephens@csadfa.cs.adfa.oz.au (Philip Stephens)
Newsgroups: comp.sys.apple
Subject: Re: C on the apple
Message-ID: <1054@ccadfa.adfa.oz.au>
Date: 5 Feb 90 01:05:05 GMT
References: <6695@wpi.wpi.edu> <12647@cbnewsd.ATT.COM> <6761@wpi.wpi.edu> <7604@wpi.wpi.edu>
Sender: news@ccadfa.adfa.oz.au
Lines: 30

In article <7604@wpi.wpi.edu>, greyelf@wpi.wpi.edu (Michael J Pender) writes:
> >In article <12054@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn) writes:
> >>The 6502 hardware stack is too small for serious
> >>C applications even if it were used only to hold return addresses.
> 
> The 65c02 wouldn't really help.  The additional instructions of the
> 65c02 are mostly concerned with a new addressing mode, a short
> range absolute branch, instructions to push and pop x and y
> on and off the stack, an instruction to store zeroes in memory,
> and the test and set bits and test and reset bits instructions.

The fact is, the 6502 (and it's equivilants) are _not_ suited for optimized
code generation or speed, in relation to high level languages such as C or
Pascal.  These languages need a large run time stack, and some decent indexing
instructions.
   Thus, the easiest way to implement C or Pascal is to get the compiler to
generate P-code (which is a stack oriented pseudo-machine language).  C
programs translate extremely easily into P-code, but you either need an
interpreter for the P-code (which is not much faster than interpreted BASIC),
or an assembler to convert P-code to 6502 code (which produces very
inefficient and _long_ object code).  Even optimized 6502 code translated from
P-code will not run as well as the code for better-suited microprocessors.

Sorry if all this has been said before.  It's hard to keep track of all the
traffic.

_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
_-_ Philip J. Stephens             -_- `My Apple II+ may only have 64K, one _-_
_-_ Department of Computer Science -_-  5 1/4 " drive, a stuffed joystick,  _-_
_-_ University College, Canberra   -_-  and run at 1 MHz; but it's mine!!!' _-_