On Mon, 13 Aug 2018 12:06:21 -0700
Cesar Philippidis <cesar@codesourcery.com> wrote:

> So in other words, this is safe for fortran. It probably could use a
> fortran test, because that functionality wasn't explicitly exercised
> in og7/og8.

Here's a new version of the patch with a Fortran test case. It's not
too easy to write a test that depends on whether gang-local variables
actually end up in the right kind of memory, so I wrote one that scans
the omplower dump instead. Many other (including execution) tests will
already trigger the new behaviour.

Tested with offloading to NVPTX.

OK?

Thanks,

Julian

2018-08-10  Julian Brown  <julian@codesourcery.com>
            Chung-Lin Tang  <cltang@codesourcery.com>

        gcc/
        * config/nvptx/nvptx.c (tree-hash-traits.h): Include.
        (gangprivate_shared_size): New global variable.
        (gangprivate_shared_align): Likewise.
        (gangprivate_shared_sym): Likewise.
        (gangprivate_shared_hmap): Likewise.
        (nvptx_option_override): Initialize gangprivate_shared_sym,
        gangprivate_shared_align.
        (nvptx_file_end): Output gangprivate_shared_sym.
        (nvptx_goacc_expand_accel_var): New function.
        (nvptx_set_current_function): New function.
        (TARGET_SET_CURRENT_FUNCTION): Define hook.
        (TARGET_GOACC_EXPAND_ACCEL): Likewise.
        * doc/tm.texi (TARGET_GOACC_EXPAND_ACCEL_VAR): Document new hook.
        * doc/tm.texi.in (TARGET_GOACC_EXPAND_ACCEL_VAR): Likewise.
        * expr.c (expand_expr_real_1): Remap decls marked with the
        "oacc gangprivate" atttribute.
        * omp-low.c (omp_context): Add oacc_partitioning_level and oacc_decls
        fields.
        (new_omp_context): Initialize oacc_decls in new omp_context.
        (delete_omp_context): Delete oacc_decls in old omp_context.
        (lower_oacc_head_tail): Record partitioning-level count in omp context.
        (oacc_record_private_var_clauses, oacc_record_vars_in_bind)
        (mark_oacc_gangprivate): New functions.
        (lower_omp_for): Call oacc_record_private_var_clauses with "for"
        clauses.  Call mark_oacc_gangprivate for gang-partitioned loops.
        (lower_omp_target): Call oacc_record_private_var_clauses with "target"
        clauses.
        Call mark_oacc_gangprivate for offloaded target regions.
        (lower_omp_1): Call vars_in_bind for GIMPLE_BIND within OMP regions.
        * target.def (expand_accel_var): New hook.

        libgomp/
        * testsuite/libgomp.oacc-c-c++-common/gang-private-1.c: New test.
        * testsuite/libgomp.oacc-c-c++-common/loop-gwv-2.c: New test.
        * testsuite/libgomp.oacc-c/pr85465.c: New test.
        * testsuite/libgomp.oacc-fortran/gangprivate-attrib-1.f90: New test.