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[mkgmap-dev] [PATCH v1] make DP filter avoid removingpointslocated at nodes

From Chris Miller chris.miller at kbcfp.com on Mon Nov 23 13:51:56 GMT 2009

Interesting, I wonder when that changed? I'm fairly sure that never used 
to be the case. I don't think it's something that you should rely on, especially 
since the VM spec says the following:

"Although the Java virtual machine defines a boolean type, it only provides 
very limited support for it. There are no Java virtual machine instructions 
solely dedicated to operations on boolean values. Instead, expressions in 
the Java programming language that operate on boolean values are compiled 
to use values of the Java virtual machine int data type.

The Java virtual machine does directly support boolean arrays. Its newarray 
instruction enables creation of boolean arrays. Arrays of type boolean are 
accessed and modified using the byte array instructions baload and bastore.2

The Java virtual machine encodes boolean array components using 1 to represent 
true and 0 to represent false. Where Java programming language boolean values 
are mapped by compilers to values of Java virtual machine type int, the compilers 
must use the same encoding."

(source: http://java.sun.com/docs/books/jvms/second_edition/html/Overview.doc.html#22909)

>> As the object sizes are rounded to multiples of 8, it looks like a
>> case of buy one, and get 7 for free!
MB> Yes, just tried that and the same amount of memory is used for 1
MB> boolean and 8 booleans.
MB> I attach the test program I am using (snarfed from the web with
MB> extra booleans added by me).
MB> Cheers,
MB> Mark

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