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From Peter Karich <peat...@yahoo.de>
Subject Re: question about inline function in java
Date Wed, 03 Nov 2010 13:05:46 GMT
  Hi,

do not ever optimize premature in java (and other jit languages like 
javascript etc)!

if you have a bottleneck -> optimize that. and only that. but take care 
how you compare statements.
be sure that you run some loops before. see the first comment of Aleksey 
Shipilev here:

http://karussell.wordpress.com/2009/05/21/microbenchmarking-java-compare-algorithms/

jit is very clever in optimizing code: so code as simple (and 'stupid') 
as possible to be understandle by jit ;-)
I.e. concentrate your time and effort on algorithms not on bytecode.

Regards,
Peter.

> hi all
>      we found function call in java will cost much time. e.g replacing
> Math.min with a<b?a:b will make it faster. Another example is lessThan
> in PriorityQueue when use Collector to gather top K documents. Yes,
> use function and subclass make it easy to maintain and extend. in
> C/C++, we can use inline fuction to optimize. What about java? I see
> many codes in lucene also inline many codes mannully.
>     such as implmented hash map in processDocument,
> SegmentTermDocs.read  "// manually inlined call to next() for speed".
>     Is there any compiler option for inline in java? Or we may hardcode
> something for time consuming tasks
>
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