On 08/31/2017 12:54 PM, Olivier Hainque wrote:
> Hello,
>
> gcc can be configured with an "e500v2" cpu target
> name, conveying SPE with double precision floats.
>
> config.gcc already has a provision for a good default
> cpu selection for SPE with double precision floats
> when the latter is explicitly requested with an explicit
> --enable command line option. This is:
>
> # If there is no $with_cpu option, try to infer one from ${target}.
> # This block sets nothing except for with_cpu.
> ...
> case ${target} in
> ...
> powerpc*-*-*spe*)
> if test x$enable_e500_double = xyes; then
> with_cpu=8548
> else
> with_cpu=8540
> fi
> ;;
>
> The attached patch is a proposal to refine this to select 8548 also
> when we were configured for an e500v2 target cpu (canonicalized to
> match powerpc-*spe), regardless of enable_e500_double.
>
> We have been using something like this in production for a few
> years in-house, lately with gcc-6 based toolchains for VxWorks or
> bareboard configurations.
>
> I also checked that
> - e500v2-wrs-vxworks builds work with gcc-7, that the default cpu is
> indeed properly set to 8548, and that the built toolchains pass Ada
> ACATS tests for a couple of runtime library variants (kernel and rtp).
>
> - a mainline build for powerpc-eabispe without --enable-e500-double
> defaults to 8540
>
> - a mainline build for powerpc-eabispe with --enable-e500-double
> defaults to 8548
>
> - a mainline build for e500v2-wrs-vxworks without --enable-e500-double
> defaults to 8548
>
> OK to commit ?
>
> Thanks in advance
>
> 2017-08-31 Olivier Hainque <hain...@adacore.com>
>
> * gcc/config.gcc (powerpc*-*-*spe*): Pick 8548 as the
> default with_cpu for an e500v2 target cpu name, in addition
> to --enable-e500-double.
GIven this hits the powerpcspe port, I'd like Andrew Jenner to chime in
as the powerpcspe maintainer. I've added him on CC.
jeff
