Re: Programming languages for the very young

From: Ray Dillinger (bear_at_sonic.net)
Date: 01/30/04 

Date: Fri, 30 Jan 2004 19:19:33 GMT

"Michael D. Ober" wrote:
>
> "Joe Marshall" <jrm@ccs.neu.edu> wrote in message
> news:3c9yep0t.fsf@ccs.neu.edu...
> > "Michael D. Ober" <obermd-.@.-alum-mit-edu-nospam> writes:
> >
> > > The last time I looked, all processors except the IBM mainframe
> processors
> > > have machine level SUB and RET instructions. These are the two
> instructions
> > > required for subroutines.
> >
> > You only need a conditional branch to get subroutines. It's a pain,
> > but you can do it.
>
> Actually, BAL does it with unconditional branches. My point was that
> subroutines are part of the stack machine model that just about every
> processor uses and that processors support them in machine code.

Yeah, okay. I'm not using the "native" subroutine instructions, because
Scheme continuations require a non-stack model of call frames. I honestly
thought those were just macros provided by my macro-assembler, but I
guess not. I am using ASM conditional branches to implement subroutine
calls.

                                Bear

Relevant Pages

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    ... > have machine level SUB and RET instructions. ... You only need a conditional branch to get subroutines. ...
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  • Re: Programming languages for the very young
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  • Re: Programming languages for the very young
    ... >> subroutines are part of the stack machine model that just about every ... I am using ASM conditional branches to implement subroutine ... It's been 20 years since I used Scheme, but I vaguely remember that Scheme ... doesn't readily lend itself to subroutines. ...
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