[gomp4] Add -foffload-abi support for PPC

[David Edelsohn]

On Wed, Oct 7, 2015 at 4:02 AM, Thomas Schwinge <thomas@codesourcery.com> wrote:

> From a quick look at the *_TYPE_SIZE definitions in
> gcc/config/rs6000/rs6000.h as well as
> <http://refspecs.linuxfoundation.org/elf/elfspec_ppc.pdf>, "3-1
> Fundamental Types", and
> <http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#FUND-TYPE>,
> I gather we're dealing with regular ilp32/lp64 here.  Then, I assume the
> right thing is to use the 64BIT flag from gcc/config/rs6000/sysv4.opt
> (which, per gcc/config.gcc I suppose is used for the relevant
> powerpc64le-linux-gnu configuration).  (David?)

TARGET_64BIT is the appropriate macro to test.

>
> I'm not sure where to place the TARGET_OFFLOAD_OPTIONS #define and the
> function definition in rs6000.c.  (David?)

As mentioned earlier, only PPC64LE is supported.

I'm not sure if it really matters if this is defined in ELF-specific
portion of the file or a general place, although it never will be
called by other configurations.

Thanks, David