Request for review(XXS): 6946892 c1 shouldn't sign-extend to upper 32bits on x64

[Tom Rodriguez]

This looks good.  Have you tested the 64 bit client much after this change?  The sign extension here could be hiding some missing sign extension at the LIR level.

tom

On Apr 23, 2010, at 9:13 PM, Igor Veresov wrote:

> C1 does sign-extension when it loads ints and shorts from memory to 64-bit registers. This causes problems for C2 because it relies on the fact the int passed in a 64-bit register is zero-extended.
> 
> Webrev: http://cr.openjdk.java.net/~iveresov/6946892/webrev.00/
> 
> Thanks,
> igor