RFR(M): 8146613: PPC64: C2 does no longer respect int to long conversion for stub calls

[Lindenmaier, Goetz]

Hi Martin, 

thanks for doing these fixes, they look good.
I especially like the trick of doing an int cast that won't be
optimized by the C compiler in the montgomery intrinsics.

You should be able to push this yourselves as you are now
Committer and it only touches ppc files.

Best regards,
  Goetz.



> -----Original Message-----
> From: hotspot-compiler-dev [mailto:hotspot-compiler-dev-
> bounces at openjdk.java.net] On Behalf Of Doerr, Martin
> Sent: Donnerstag, 7. Januar 2016 14:55
> To: hotspot-compiler-dev at openjdk.java.net
> Subject: RFR(M): 8146613: PPC64: C2 does no longer respect int to long
> conversion for stub calls
> 
> Hi,
> 
> 
> 
> I have created a webrev which introduces int to long conversion in PPC64
> functions which are called by C2 runtime calls.
> 
> I also added assertions to arraycopy stubs which are already called correctly.
> 
> 
> 
> Background:
> 8086069 removed too much code. Only the native wrapper performed the
> conversion after this change. However, it is required to convert ints to longs
> for all C calls and some runtime calls.
> 8144466 reintroduced the platform variable
> CCallingConventionRequiresIntsAsLongs and the conversion for the runtime
> calls for which C2 calls shared C functions on PPC64.
> Some PPC64 runtime functions which rely on proper 64 bit arguments are still
> called without conversion.
> 
> Webrev is here:
> 
> http://cr.openjdk.java.net/~mdoerr/8146613_ppc64_int2long/webrev.00/
> 
> 
> 
> It only touches PPC64 files.
> 
> 
> 
> Please review and sponsor.
> 
> 
> 
> Best regards,
> 
> Martin
> 
>