[PATCH v3 00/10] AMD GCN Port v3

[Andrew Stubbs]

New year ping!

The last remaining middle-end patch was already applied, so it's only 
the backend, config, and testsuite patches remaining to be committed. 
And, it's mostly only the back end still requiring review.

Hopefully I should still be able to get them reviewed and committed in 
time for GCC 9, given that disruption to other targets should no longer 
be an issue?

Andrew

On 12/12/2018 11:52, Andrew Stubbs wrote:
> This is the third rework of the patchset previously posted on September
> 5th and November 16th. As before, the series contains the
> non-OpenACC/OpenMP portions of a port to AMD GCN3 and GCN5 GPU
> processors.  It's sufficient to build single-threaded programs, with
> vectorization in the usual way.  C and Fortran are supported, C++ is not
> supported, and the other front-ends have not been tested.  The
> OpenACC/OpenMP/libgomp portion will follow, once this is committed,
> eventually.
> 
> Compared to the v2 patchset, patch 1, "Fix IRA ICE", has been dropped,
> and a new, unrelated, patch 1 has been added: "Fix LRA bug".
> 
> The IRA issue has now been solved by reworking the move instructions in
> the back-end so that they no longer require explicit mention of the EXEC
> register (this is now managed mostly by the md_reorg pass).  I also took
> the opportunity to rework the EXEC use throughout the machine
> description (something I've been wanting to get to for ages); the
> primary instruction patterns no longer use vec_merge, and there are
> "_exec" variants defined (mostly via define_subst) for the use of
> specific expanders and so that combine can optimize conditional vector
> moves.
> 
> Additionally, the patterns that choose which unit to use for
> scalar operations now only clobber the relevant condition register (via
> a match_scratch), not both of them.
> 
> The new LRA issue was exposed by the above changes, but would affect any
> target where patterns referring to an eliminable register might also
> include a "scratch" register.
> 
> I've also addressed the various feedback I received from patch
> reviewers.
>