Optimize signed integer comparison

[John Rose]

On Jul 18, 2014, at 2:58 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:

>> 
>> Alternatively, and more powerfully, we could add bitfield tracking to the type system.  Graal has this (based on type equations I sent them).  If we were to do both range and bitfield tracking of the {-1,0,1} range of Cmp operations, we could express the type NE using the type assertion "(cmp&-2)!=0" which can be coded as "downMask!=0".
> 
> It is out of scope of these changes. Should be filed separate RFE.

Already done as JDK-8001436; I linked the bugs FTR.  — John
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/attachments/20140718/4b3b529c/attachment.html>