3 ms·

Not meant to be a thread hijack, but I guess it is anyway... I put up a blog post last night with some troubles I was having in Gambit (my site with the post:

Not meant to be a thread hijack, but I guess it is anyway... I put up a blog post last night with some troubles I was having in Gambit (my site with the post: http://etherplex.org http://etherplex.org) I'm very new to non-JVM hosted languages, so I'm not yet sensitive to where the performance pitfalls are. Essentially, a professor of mine gave me a program in C that boiled down to a for loop doing 144 million iterations with a check inside of it, and an increment if the check passes. The C program runs in 1 second, and the straight port to Gambit I attempted runs in about 8 minutes. I posted code, in hopes someone might spot my error. Are nested do statements or let statements particularly expensive, or did I make some bone-headed mistake somewhere when I ported it over? It's not meant to be functional (yet), I thought I'd just start with an imperative implementation and go from there, since that was what the original code was. Thoughts?

jlongster 17y ago
I will take a look at it later tonight. But the first thing you need to do is add this to the top of your Scheme file: (declare (block) (standard-bindings) (extended-bindings)) These are statements to let the compiler optimize things, losing some dynamicism. That should increase it a lot. When it comes to tight loops, Gambit doesn't usually do as good of a job because of its garbage collector (it doesn't optimize for lots of small short-lived objects), which is planned to be fixed in the future.
- rpdillon 17y ago
  Thanks very much...those settings don't seem to help much, but they've led me to the area of the documentation that I haven't looked at before. I'll read through it and learn a bit more about the compiler settings.
grettke 17y ago
You might post it to a Scheme related list: http://www.wisdomandwonder.com/scheme http://www.wisdomandwonder.com/scheme

jlongster 17y ago

I will take a look at it later tonight. But the first thing you need to do is add this to the top of your Scheme file: (declare (block) (standard-bindings) (extended-bindings)) These are statements to let the compiler optimize things, losing some dynamicism. That should increase it a lot. When it comes to tight loops, Gambit doesn't usually do as good of a job because of its garbage collector (it doesn't optimize for lots of small short-lived objects), which is planned to be fixed in the future.

rpdillon 17y ago
Thanks very much...those settings don't seem to help much, but they've led me to the area of the documentation that I haven't looked at before. I'll read through it and learn a bit more about the compiler settings.

grettke 17y ago

You might post it to a Scheme related list: http://www.wisdomandwonder.com/scheme http://www.wisdomandwonder.com/scheme