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

Igor Veresov igor.veresov at
Tue Apr 27 08:46:57 PDT 2010

Thank you, Tom!

I've tested with SPECjvm98 and SPECjvm2008, they work ok. I'll keep an 
eye on related things that may bubble up.


On 4/26/10 12:16 PM, Tom Rodriguez wrote:
> 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:
>> Thanks,
>> igor

More information about the hotspot-compiler-dev mailing list