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From Paul Smith <>
Subject Re: Float.floatToRawIntBits
Date Wed, 16 Nov 2005 22:31:01 GMT

On 17/11/2005, at 9:24 AM, Doug Cutting wrote:

> In general I would not take this sort of profiler output too  
> literally.  If floatToRawIntBits is 5x faster, then you'd expect a  
> 16% improvement from using it, but my guess is you'll see far  
> less.  Still, it's probably worth switching & measuring as it might  
> be significant.

Yes I don't think we'll get 5x speed update, as it will likely move  
the bottleneck back to the IO layer, but still...  If you can reduce  
CPU usage, then multithreaded indexing operations can gain better CPU  
utilization (doing other stuff while waiting for IO).  Seems like an  
easy win and dead easy to unit test?

I've been meaning to have a crack at reworking FastCharStream but  
everytime I start thinking about it I realise there is a bit of a  
depency on this IOExecption signalling EOF that I'm pretty sure it's  
going to be much harder task.  The JavaCC stuff is really designed  
for compiling tree's which is usually a 'once off' type usage, but  
Lucenes usage of it (large indexing operations) means the flaws in it  
are exacerbated.


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