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devel / comp.lang.lisp / Re: Simple arithmetic consumes tons of CPU and memory in SBCL

Re: Simple arithmetic consumes tons of CPU and memory in SBCL

<845yxgl9ed.fsf@gmail.com>

https://www.rocksolidbbs.com/devel/article-flat.php?id=16638&group=comp.lang.lisp#16638

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NNTP-Posting-Date: Sun, 11 Jul 2021 18:26:34 -0500
From: sgonedes1977@gmail.com (steve)
Newsgroups: comp.lang.lisp
Subject: Re: Simple arithmetic consumes tons of CPU and memory in SBCL
References: <rr8q69$9iq$1@dont-email.me>
Date: Sun, 11 Jul 2021 19:26:34 -0400
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by: steve - Sun, 11 Jul 2021 23:26 UTC

Andrew Sengul <ml@scenariotech.invalid> writes:

> Hi everyone, I've found something strange while profiling a function in
> SBCL. Said function runs a (dotimes) loop and copies elements from one
> array to another. Here is the first loop and its (time) profile:

the math you are using conses - that is to say it uses memory. You are
calling setf many many times, it is usually better to reduce the number
of function calls.

I usually use something like so...

(fill buffer 0 :start 1 :end +max-number-count+)

so such. replace or map-into...

compile the function and (disassemble 'function)

Subject	Author
Re: Simple arithmetic consumes tons of CPU and memory in SBCL	steve