OpenJDK7 port to the little endian PowerPC64

[Lindenmaier, Goetz]

Hi Alexander, 

> My only question is why it was necessary to have explicit
> #include "macroAssembler_ppc.inline.hpp"
In jdk7u I split assembler and macroAssembler as it is in jdk8/9.
This simplifies keeping the port the same in all repos.
But as the corresponding changes in shared code are missing, 
I just include macroAssembler.inline.hpp in assembler.inline.hpp.
In jdk8/9, I need the include and in 7  I added it for symmetry.

As you also want to go to 8/9, I would propose that we first get
the abi and the little endian change reviewed for 8/9, before we 
push the little endian change to 7, to make sure it looks the
same in all repos.  What do you think?  Do you have any constraints
on getting the changes into 7?

I opened a bug for the ELFv2 issue to get it into 9:
https://bugs.openjdk.java.net/browse/JDK-8035647

Best regards,
  Goetz.



-----Original Message-----
From: Alexander Smundak [mailto:asmundak at google.com] 
Sent: Mittwoch, 19. Februar 2014 02:52
To: Lindenmaier, Goetz
Cc: ppc-aix-port-dev at openjdk.java.net
Subject: Re: OpenJDK7 port to the little endian PowerPC64

> I would propose to split the hotspot change into the fixes for the
> new abi and those for the endianess. The abi changes are almost ppc-only
> and thus easier to get reviewed. I prepared a change including only
> that:
> http://cr.openjdk.java.net/~goetz/webrevs/abi_elfv2/
Thank you for doing this. Your patch works, and the remaining patch is
much smaller.
My only question is why it was necessary to have explicit
#include "macroAssembler_ppc.inline.hpp"
in src/cpu/ppc/vm/vm_version_ppc.cpp as  "assembler_ppc.inline.hpp"
which is one line above, already does that.

> Please have a look at this change and test it.  . Feel free to further
> change it.  If the change is ok for you I'll push it right away
Yes, please do.

I've addressed your remaining comments and will post revised diff once
you submit elfv2 change and I pull it.
Do you have any comments on jdk/ change?

> For the remaining changes to hotspot it would be great if we could
> avoid all the duplication of files.... I think you just need to change
> arch_model and os_arch_model in platform_ppc64le.
Yes, this works.

> I would prefer if you use VM_LITTLE_ENDIAN to distinguish in C-code
Done.

> Did you build and use SA? Does it work? So far, we never tried to.
Yes, I've built it, but it's not very useful until
agent/src/share/classes/sun/jvm/hotspot/runtime/ contains powerpc64-specific
classes. It's not worth putting it into this patch.

> Your change in os_linux.cpp to arch_array looks wrong. As you use
> the same code entry for both ppc64, in the loop below, running_arch_code
> will always point to your new entry.
Fixed that.

> Further I think, the CPU architecture string should be
>
> #elif defined(PPC64)
> #ifdef VM_LITTLE_ENDIAN
> static char cpu_arch[] = "ppc64le";
> #else
> static char cpu_arch[] = "ppc64";
> #endif
Done.