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hyln9 / ikarus

Optimizing incremental native-code compiler for R6RS scheme. This is a forked repository.
https://launchpad.net/ikarus
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Slow to print long vectors #235

Open hyln9 opened 10 years ago

hyln9 commented 10 years ago

Printing out long vectors has a noticeable delay before getting started. I'm guessing it is doing a cycle check, but the delay is long enough that the first couple times I thought Ikarus had crashed. Whatever it is doing should be profiled and if possible the performance improved.

$ ikarus Ikarus Scheme version 0.0.3+ (revision 1692, build 2008-11-25) Copyright (c) 2006-2008 Abdulaziz Ghuloum

(define x (make-vector #x10FFFF)) x <... noticable (3-5 second) delay ...>

(0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ...

Launchpad Details: #LP304399 Michael D. Adams - 2008-12-02 08:44:37 -0500

hyln9 commented 10 years ago

On Dec 2, 2008, at 8:44 AM, Michael D. Adams wrote:

Printing out long vectors has a noticeable delay before getting
started. I'm guessing it is doing a cycle check, but the delay is long enough that the first couple times I thought Ikarus had crashed. Whatever it is doing should be profiled and if possible the performance improved.

It's not due to the cycle check. Write/display both do the cycle check and both come back immediately. It's just pretty-print that's dog slow.

The algorithm that I came up with for computing the layout is
inefficient. It does pretty-print the code nicely, but at a huge cost as you can see.

There may be places in the pretty-printer that can be improved, but at its current structure, it will still be slow for other cases. It's
would be better to fix the algorithm (aka. rewrite the pretty printer) than to do minor fixes to the implementation.

This is not cheap. It will have to wait for the next fiscal year budget structuring books to come out to see if we can put this somewhere. :-)

Aziz,,,

Launchpad Details: #LPC Abdulaziz Ghuloum - 2008-12-02 17:28:20 -0500

hyln9 commented 10 years ago

Marking as wishlist. (the classifications of lanuchpad's "status" and "importance" are pretty sad)

Launchpad Details: #LPC Abdulaziz Ghuloum - 2008-12-05 02:26:13 -0500