patch to enable LRA for ppc

[David Edelsohn]

On Thu, Oct 3, 2013 at 5:02 PM, Vladimir Makarov <vmakarov@redhat.com> wrote:
> The following patch permits today trunk to use LRA for ppc by default.
> To switch it off -mno-lra can be used.
>
> The patch was bootstrapped on ppc64.  GCC testsuite does not have
> regressions too (in comparison with reload).  The change in rs6000.md is
> for fix LRA failure on a recently added ppc test.

Vlad,

I have not forgotten this patch. We are trying to figure out the right
timeframe to make this change. The patch does affect performance --
both positively and negatively; most are in the noise but not all. And
there still are some SPEC benchmarks that fail to build with the
patch, at least in Mike's tests. And Mike is implementing some patches
to utilize reload to improve use of VSX registers, which would need to
be mirrored in LRA for the equivalent functionality.

Thanks, David