8154867: PPC64: Better byte behavior

[Coleen Phillimore]

Hi Martin,

http://cr.openjdk.java.net/~mdoerr/8154867_PPC64_Better_byte_behavior/webrev.00/src/cpu/ppc/vm/templateTable_ppc_64.cpp.udiff.html

This change looks good except the code in ireturn looks strange because 
state is never btos/ztos/stos/ctos.  OR if it was btos,stos and ctos and 
you're trying to return a boolean, there would have to be additional 
narrowing for those cases too.  It think it would be more accurate to 
have the small int tos states above itos in your switch statement.

The only reason we added ztos was to make the backports easier for these 
bugs.  I think these unused tos optimization cases should be removed.  
Do you agree?
https://bugs.openjdk.java.net/browse/JDK-8139788


Also, I guess it doesn't matter for ppc, but the April cpu code is in 
http://hg.openjdk.java.net/jdk9/hs and I was going to push the zero 
change from Severin there.  Should you make these changes for that 
repository instead?

thanks,
Coleen


On 4/22/16 4:55 AM, Doerr, Martin wrote:
> Hi,
>
> the PPC64 part of "Better byte behavior" (8148487) was done in jdk8u but is also needed in 9.
>
> Here's the port for 9/dev:
> http://cr.openjdk.java.net/~mdoerr/8154867_PPC64_Better_byte_behavior/webrev.00/
>
> Please review.
>
> Best regards,
> Martin
>