OpenEuphoria

Re: Need help with PD source (again)

• Posted by Matt Lewis <matthewwalkerlewis at gmail.com> Apr 05, 2005
• 418 views

Pete Lomax wrote:
> 
> On Mon, 04 Apr 2005 10:25:10 -0700, Matt Lewis
> <guest at RapidEuphoria.com> wrote:
> 
> >Pete Lomax wrote:
> >> 
> >> >
> >> Matt Lewis wrote:
> >> > So it's those ENDFOR_INT_UP1's and ENDFOR_GENERAL's that you need to 
> >> > reproduce.
> >>
> >> You would need additional goto's after them, to properly exit the
> >> loop, should you be on the last iteration. I think you would be better
> >> off jumping to the existing endfor/endwhile statement instead.
> >> Branch straightening might tidy things up automatically, with luck.
> >
> >That seems wasteful (execution-wise) 
> Yes, an extra jump,... but, otoh, slightly less code ).
> >and requires changing the back end,
> Not sure why you think that. Please elaborate.

Aha.  Now that I see your code, I understand what you're saying.  I was
thinking that there's no simple GOTO opcode in the interpreter, but of
course, there is, and it's called EXIT.  You just have to backpatch the
address.  Very slick.

> 
> Like I said, I have not tested it, it was just a simple suggestion I
> thought would do the trick. Maybe the comparison will be useful
> anyway.

Definitely useful.  Have to consider whether slightly larger code 
(about 5 opcodes per use of next/continue) vs the extra jump.

Matt Lewis