From: Tom de Vries <Tom_deVries@mentor.com>
To: "gcc-patches@gnu.org" <gcc-patches@gnu.org>
Subject: [PING][PATCH, PR66851] Handle double reduction in parloops
Date: Fri, 24 Jul 2015 10:55:00 -0000 [thread overview]
Message-ID: <55B213DD.4050602@mentor.com> (raw)
In-Reply-To: <55A3D170.6080304@mentor.com>
On 13/07/15 16:55, Tom de Vries wrote:
> Hi,
>
> this patch fixes PR66851.
>
> In parloops, we manage to parallelize outer loops, but not if the inner
> loop contains a reduction. There is an xfail in autopar/outer-4.c for this:
> ...
> /* { dg-final { scan-tree-dump-times "parallelizing outer loop" 1
> "parloops" { xfail *-*-* } } } */
> ...
>
> This patch allows outer loops with a reduction in the inner loop to be
> parallelized.
>
> Bootstrapped and reg-tested on x86_64.
>
> OK for trunk?
>
Ping ( original posting at
https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01057.html ).
Thanks,
- Tom
> 0001-Handle-double-reduction-in-parloops.patch
>
>
> Handle double reduction in parloops
>
> 2015-07-13 Tom de Vries<tom@codesourcery.com>
>
> PR tree-optimization/66851
> * tree-parloops.c (reduc_stmt_res): New function.
> (initialize_reductions, add_field_for_reduction)
> (create_phi_for_local_result, create_loads_for_reductions)
> (create_stores_for_reduction, build_new_reduction): Handle case that
> reduc_stmt is a phi.
> (gather_scalar_reductions): Allow double_reduc reductions.
>
> * gcc.dg/autopar/outer-4.c (parloop): Remove superfluous noinline
> attribute. Remove xfail on scan for parallelizing outer loop.
> (main): Remove.
>
> * testsuite/libgomp.c/outer-4.c: New test.
> ---
> gcc/testsuite/gcc.dg/autopar/outer-4.c | 17 ++++------------
> gcc/tree-parloops.c | 37 +++++++++++++++++++++++++---------
> libgomp/testsuite/libgomp.c/outer-4.c | 36 +++++++++++++++++++++++++++++++++
> 3 files changed, 68 insertions(+), 22 deletions(-)
> create mode 100644 libgomp/testsuite/libgomp.c/outer-4.c
>
> diff --git a/gcc/testsuite/gcc.dg/autopar/outer-4.c b/gcc/testsuite/gcc.dg/autopar/outer-4.c
> index 6fd37c5..f435080 100644
> --- a/gcc/testsuite/gcc.dg/autopar/outer-4.c
> +++ b/gcc/testsuite/gcc.dg/autopar/outer-4.c
> @@ -6,15 +6,13 @@ void abort (void);
> int g_sum=0;
> int x[500][500];
>
> -__attribute__((noinline))
> -void parloop (int N)
> +void
> +parloop (int N)
> {
> int i, j;
> int sum;
>
> - /* Double reduction is currently not supported, outer loop is not
> - parallelized. Inner reduction is detected, inner loop is
> - parallelized. */
> + /* Double reduction is detected, outer loop is parallelized. */
> sum = 0;
> for (i = 0; i < N; i++)
> for (j = 0; j < N; j++)
> @@ -23,13 +21,6 @@ void parloop (int N)
> g_sum = sum;
> }
>
> -int main(void)
> -{
> - parloop(500);
> -
> - return 0;
> -}
> -
>
> -/* { dg-final { scan-tree-dump-times "parallelizing outer loop" 1 "parloops" { xfail *-*-* } } } */
> +/* { dg-final { scan-tree-dump-times "parallelizing outer loop" 1 "parloops" } } */
> /* { dg-final { scan-tree-dump-times "loopfn" 4 "optimized" } } */
> diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
> index 21ed17b..db7da62 100644
> --- a/gcc/tree-parloops.c
> +++ b/gcc/tree-parloops.c
> @@ -560,6 +560,14 @@ take_address_of (tree obj, tree type, edge entry,
> return name;
> }
>
> +static tree
> +reduc_stmt_res (gimple stmt)
> +{
> + return (gimple_code (stmt) == GIMPLE_PHI
> + ? gimple_phi_result (stmt)
> + : gimple_assign_lhs (stmt));
> +}
> +
> /* Callback for htab_traverse. Create the initialization statement
> for reduction described in SLOT, and place it at the preheader of
> the loop described in DATA. */
> @@ -586,7 +594,7 @@ initialize_reductions (reduction_info **slot, struct loop *loop)
> c = build_omp_clause (gimple_location (reduc->reduc_stmt),
> OMP_CLAUSE_REDUCTION);
> OMP_CLAUSE_REDUCTION_CODE (c) = reduc->reduction_code;
> - OMP_CLAUSE_DECL (c) = SSA_NAME_VAR (gimple_assign_lhs (reduc->reduc_stmt));
> + OMP_CLAUSE_DECL (c) = SSA_NAME_VAR (reduc_stmt_res (reduc->reduc_stmt));
>
> init = omp_reduction_init (c, TREE_TYPE (bvar));
> reduc->init = init;
> @@ -993,7 +1001,7 @@ add_field_for_reduction (reduction_info **slot, tree type)
> {
>
> struct reduction_info *const red = *slot;
> - tree var = gimple_assign_lhs (red->reduc_stmt);
> + tree var = reduc_stmt_res (red->reduc_stmt);
> tree field = build_decl (gimple_location (red->reduc_stmt), FIELD_DECL,
> SSA_NAME_IDENTIFIER (var), TREE_TYPE (var));
>
> @@ -1053,12 +1061,12 @@ create_phi_for_local_result (reduction_info **slot, struct loop *loop)
> e = EDGE_PRED (store_bb, 1);
> else
> e = EDGE_PRED (store_bb, 0);
> - local_res = copy_ssa_name (gimple_assign_lhs (reduc->reduc_stmt));
> + tree lhs = reduc_stmt_res (reduc->reduc_stmt);
> + local_res = copy_ssa_name (lhs);
> locus = gimple_location (reduc->reduc_stmt);
> new_phi = create_phi_node (local_res, store_bb);
> add_phi_arg (new_phi, reduc->init, e, locus);
> - add_phi_arg (new_phi, gimple_assign_lhs (reduc->reduc_stmt),
> - FALLTHRU_EDGE (loop->latch), locus);
> + add_phi_arg (new_phi, lhs, FALLTHRU_EDGE (loop->latch), locus);
> reduc->new_phi = new_phi;
>
> return 1;
> @@ -1151,7 +1159,7 @@ create_loads_for_reductions (reduction_info **slot, struct clsn_data *clsn_data)
> struct reduction_info *const red = *slot;
> gimple stmt;
> gimple_stmt_iterator gsi;
> - tree type = TREE_TYPE (gimple_assign_lhs (red->reduc_stmt));
> + tree type = TREE_TYPE (reduc_stmt_res (red->reduc_stmt));
> tree load_struct;
> tree name;
> tree x;
> @@ -1212,7 +1220,7 @@ create_stores_for_reduction (reduction_info **slot, struct clsn_data *clsn_data)
> tree t;
> gimple stmt;
> gimple_stmt_iterator gsi;
> - tree type = TREE_TYPE (gimple_assign_lhs (red->reduc_stmt));
> + tree type = TREE_TYPE (reduc_stmt_res (red->reduc_stmt));
>
> gsi = gsi_last_bb (clsn_data->store_bb);
> t = build3 (COMPONENT_REF, type, clsn_data->store, red->field, NULL_TREE);
> @@ -2321,6 +2329,7 @@ build_new_reduction (reduction_info_table_type *reduction_list,
> {
> reduction_info **slot;
> struct reduction_info *new_reduction;
> + enum tree_code reduction_code;
>
> gcc_assert (reduc_stmt);
>
> @@ -2332,12 +2341,22 @@ build_new_reduction (reduction_info_table_type *reduction_list,
> fprintf (dump_file, "\n");
> }
>
> + if (gimple_code (reduc_stmt) == GIMPLE_PHI)
> + {
> + tree op1 = PHI_ARG_DEF (reduc_stmt, 0);
> + gimple def1 = SSA_NAME_DEF_STMT (op1);
> + reduction_code = gimple_assign_rhs_code (def1);
> + }
> +
> + else
> + reduction_code = gimple_assign_rhs_code (reduc_stmt);
> +
> new_reduction = XCNEW (struct reduction_info);
>
> new_reduction->reduc_stmt = reduc_stmt;
> new_reduction->reduc_phi = phi;
> new_reduction->reduc_version = SSA_NAME_VERSION (gimple_phi_result (phi));
> - new_reduction->reduction_code = gimple_assign_rhs_code (reduc_stmt);
> + new_reduction->reduction_code = reduction_code;
> slot = reduction_list->find_slot (new_reduction, INSERT);
> *slot = new_reduction;
> }
> @@ -2378,7 +2397,7 @@ gather_scalar_reductions (loop_p loop, reduction_info_table_type *reduction_list
> gimple reduc_stmt = vect_force_simple_reduction (simple_loop_info,
> phi, true,
> &double_reduc);
> - if (reduc_stmt && !double_reduc)
> + if (reduc_stmt)
> build_new_reduction (reduction_list, reduc_stmt, phi);
> }
> }
> diff --git a/libgomp/testsuite/libgomp.c/outer-4.c b/libgomp/testsuite/libgomp.c/outer-4.c
> new file mode 100644
> index 0000000..f77f634
> --- /dev/null
> +++ b/libgomp/testsuite/libgomp.c/outer-4.c
> @@ -0,0 +1,36 @@
> +/* { dg-do run } */
> +/* { dg-additional-options "-ftree-parallelize-loops=2" } */
> +
> +void abort (void);
> +
> +int g_sum = 1;
> +
> +int x[500][500];
> +
> +void __attribute__((noinline,noclone))
> +parloop (int N)
> +{
> + int i, j;
> + int sum;
> +
> + /* Double reduction is detected, outer loop is parallelized. */
> + sum = 0;
> + for (i = 0; i < N; i++)
> + for (j = 0; j < N; j++)
> + sum += x[i][j];
> +
> + g_sum = sum;
> +}
> +
> +int
> +main (void)
> +{
> + x[234][432] = 2;
> +
> + parloop (500);
> +
> + if (g_sum != 2)
> + abort ();
> +
> + return 0;
> +}
> -- 1.9.1
>
next prev parent reply other threads:[~2015-07-24 10:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-13 14:56 [PATCH, " Tom de Vries
2015-07-24 10:55 ` Tom de Vries [this message]
2015-07-27 23:12 ` [PING][PATCH, " Tom de Vries
2015-07-28 8:01 ` Richard Biener
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