Re: Math patch

[Artur Biesiadowski]

Chris Gray wrote:

> Nonetheless, javac certainly used to do that, and I'm pretty sure it still 
> does. (I could swear that the JLS actually specifies this behaviour, but 
> I'm darned if I can find the words now.)  

13.4.8

http://java.sun.com/docs/books/jls/second_edition/html/binaryComp.doc.html#45139

[...]
One reason for requiring inlining of constants is that switch statements 
require constants on each case, and no two such constant values may be 
the same. The compiler checks for duplicate constant values in a switch 
statement at compile time; the class file format does not do symbolic 
linkage of case values
[...]

Instead of doing checks on both compile and then runtime link time 
(check would be really trivial), they have decided to go this broken 
route. Major reason for that is probably speed of interpreter versus 
boolean debug flag - jit could trivially reject dead branch, with 
interpreter it is not so obvious.

Artur