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https://issues.apache.org/jira/browse/LUCENE-3795?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13230574#comment-13230574
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Yonik Seeley commented on LUCENE-3795:
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bq. I'd be very surprised to hear if this is true.
If Math.toRadians had been written as x*(PI/180.0) then the compiler would have
done constant folding and it would simply be multiplication by a constant. But
it's unfortunately written as x/180.0*PI (for no good reason in this case), and
the compiler/JVM is not allowed to do the simple transformation by itself.
That's why we do it.
Sometimes knowing how optimizers work and the restrictions on them allow one to
know what will be faster or slower without benchmarking. I did benchmark it
after the fact (after you questioned it), and it was indeed the case that
Math.toRadians was much slower than a simple multiply.
> Replace spatial contrib module with LSP's spatial-lucene module
> ---------------------------------------------------------------
>
> Key: LUCENE-3795
> URL: https://issues.apache.org/jira/browse/LUCENE-3795
> Project: Lucene - Java
> Issue Type: New Feature
> Components: modules/spatial
> Reporter: David Smiley
> Assignee: David Smiley
> Fix For: 4.0
>
>
> I propose that Lucene's spatial contrib module be replaced with the
> spatial-lucene module within Lucene Spatial Playground (LSP). LSP has been
> in development for approximately 1 year by David Smiley, Ryan McKinley, and
> Chris Male and we feel it is ready. LSP is here:
> http://code.google.com/p/lucene-spatial-playground/ and the spatial-lucene
> module is intuitively in svn/trunk/spatial-lucene/.
> I'll add more comments to prevent the issue description from being too long.
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