This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH, 10/16] Add pass_oacc_kernels pass group in passes.def


On Mon, 9 Nov 2015, Tom de Vries wrote:

> On 09/11/15 16:35, Tom de Vries wrote:
> > Hi,
> > 
> > this patch series for stage1 trunk adds support to:
> > - parallelize oacc kernels regions using parloops, and
> > - map the loops onto the oacc gang dimension.
> > 
> > The patch series contains these patches:
> > 
> >       1    Insert new exit block only when needed in
> >          transform_to_exit_first_loop_alt
> >       2    Make create_parallel_loop return void
> >       3    Ignore reduction clause on kernels directive
> >       4    Implement -foffload-alias
> >       5    Add in_oacc_kernels_region in struct loop
> >       6    Add pass_oacc_kernels
> >       7    Add pass_dominator_oacc_kernels
> >       8    Add pass_ch_oacc_kernels
> >       9    Add pass_parallelize_loops_oacc_kernels
> >      10    Add pass_oacc_kernels pass group in passes.def
> >      11    Update testcases after adding kernels pass group
> >      12    Handle acc loop directive
> >      13    Add c-c++-common/goacc/kernels-*.c
> >      14    Add gfortran.dg/goacc/kernels-*.f95
> >      15    Add libgomp.oacc-c-c++-common/kernels-*.c
> >      16    Add libgomp.oacc-fortran/kernels-*.f95
> > 
> > The first 9 patches are more or less independent, but patches 10-16 are
> > intended to be committed at the same time.
> > 
> > Bootstrapped and reg-tested on x86_64.
> > 
> > Build and reg-tested with nvidia accelerator, in combination with a
> > patch that enables accelerator testing (which is submitted at
> > https://gcc.gnu.org/ml/gcc-patches/2015-10/msg01771.html ).
> > 
> > I'll post the individual patches in reply to this message.
> > 
> 
> This patch adds the pass_oacc_kernels pass group to the pass list in
> passes.def.
> 
> Note the repetition of pass_lim/pass_copy_prop. The first pair is for an inner
> loop in a loop nest, the second for an outer loop in a loop nest.

@@ -86,6 +86,27 @@ along with GCC; see the file COPYING3.  If not see
          /* pass_build_ealias is a dummy pass that ensures that we
             execute TODO_rebuild_alias at this point.  */
          NEXT_PASS (pass_build_ealias);
+         /* Pass group that runs when there are oacc kernels in the
+            function.  */
+         NEXT_PASS (pass_oacc_kernels);
+         PUSH_INSERT_PASSES_WITHIN (pass_oacc_kernels)
+             NEXT_PASS (pass_dominator_oacc_kernels);
+             NEXT_PASS (pass_ch_oacc_kernels);
+             NEXT_PASS (pass_dominator_oacc_kernels);
+             NEXT_PASS (pass_tree_loop_init);
+             NEXT_PASS (pass_lim);
+             NEXT_PASS (pass_copy_prop);
+             NEXT_PASS (pass_lim);
+             NEXT_PASS (pass_copy_prop);

iterate lim/copyprop twice?!  Why's that needed?

+             NEXT_PASS (pass_scev_cprop);

What's that for?  It's supposed to help removing loops - I don't
expect kernels to vanish.

+             NEXT_PASS (pass_tree_loop_done);
+             NEXT_PASS (pass_dominator_oacc_kernels);

Three times DOM?  No please.  I wonder why you don't run oacc_kernels
after FRE and drop the initial DOM(s).

+             NEXT_PASS (pass_dce);
+             NEXT_PASS (pass_tree_loop_init);
+             NEXT_PASS (pass_parallelize_loops_oacc_kernels);
+             NEXT_PASS (pass_expand_omp_ssa);
+             NEXT_PASS (pass_tree_loop_done);

The switches into/outof tree_loop also look odd to me, but well
(they'll be controlled by -ftree-loop-optimize)).

+         POP_INSERT_PASSES ()

Please get some more sense into this pass pipeline.

Richard.


> Thanks,
> - Tom
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]