Please Review (XXXS): Fix for 6887186: G1: Incorrect code generated for G1 pre-barrier by C1 on SPARC

[john cuthbertson - Sun Microsystems]

Hi Everyone,

Can I have a couple of volunteers review the changes for this CR? The 
webrev can be found at http://cr.openjdk.java.net/~johnc/6887186/webrev.0/.

The issue is that the wrong C1 operand was passed to the generator of 
the G1 pre-barrier code for the Unsafe.CompareAndSwap intrinsic. The old 
code was passing the operand representing the base object rather than 
that representing the address of the object.field that was passed to the 
CAS. This caused the G1 pre-barrier code to store a mark word in the 
SATB buffer rather than the previous contents of object.field.

Thanks,

JohnC