OpenMP 5.0: Allow multiple clauses mapping same variable

This is a merge of:
https://gcc.gnu.org/pipermail/gcc-patches/2020-December/562081.html

This patch now allows multiple clauses on the same construct to map
the same variable, which was not valid in OpenMP 4.5, but now allowed
in 5.0.

This may possibly reverted/updated when a final patch is approved
for mainline.

2021-02-01  Chung-Lin Tang  <cltang@codesourcery.com>

gcc/cp/ChangeLog:

	* semantics.cc (finish_omp_clauses):  Adjust to allow duplicate
	mapped variables for OpenMP.

gcc/ChangeLog:

	* omp-low.cc (install_var_field): Add new 'tree key_expr = NULL_TREE'
	default parameter. Set splay-tree lookup key to key_expr instead of
	var if key_expr is non-NULL. Adjust call to install_parm_decl.
	Update comments.
	(scan_sharing_clauses): Use clause tree expression as splay-tree key
	for map/to/from and OpenACC firstprivate cases when installing the
	variable field into the send/receive record type.
	(maybe_lookup_field_in_outer_ctx): Add code to search through
	construct clauses instead of entirely based on splay-tree lookup.
	(lower_oacc_reductions): Adjust to find map-clause of reduction
	variable, then create receiver-ref.
	(lower_omp_target): Adjust to lookup var field using clause expression.

gcc/testsuite/ChangeLog:

	* c-c++-common/gomp/clauses-2.c: Adjust testcase.

diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp
index b977f98af97902ab1ff476914a1434267c208327..3d13da044f0b2fa46bc55af088e51aae5be82119 100644 (file)
--- a/gcc/ChangeLog.omp
+++ b/gcc/ChangeLog.omp
@@ -1,3 +1,18 @@
+2021-02-01  Chung-Lin Tang  <cltang@codesourcery.com>
+
+       * omp-low.cc (install_var_field): Add new 'tree key_expr = NULL_TREE'
+       default parameter. Set splay-tree lookup key to key_expr instead of
+       var if key_expr is non-NULL. Adjust call to install_parm_decl.
+       Update comments.
+       (scan_sharing_clauses): Use clause tree expression as splay-tree key
+       for map/to/from and OpenACC firstprivate cases when installing the
+       variable field into the send/receive record type.
+       (maybe_lookup_field_in_outer_ctx): Add code to search through
+       construct clauses instead of entirely based on splay-tree lookup.
+       (lower_oacc_reductions): Adjust to find map-clause of reduction
+       variable, then create receiver-ref.
+       (lower_omp_target): Adjust to lookup var field using clause expression.
+
 2021-01-16  Andrew Stubbs  <ams@codesourcery.com>
 
        * dwarf2out.cc (gen_subprogram_die): Check offload attributes only.

diff --git a/gcc/cp/ChangeLog.omp b/gcc/cp/ChangeLog.omp
index d8156d528c6b2e163e9ec0381576b9e7369c5bc9..1c7df9a15a03174a4af677a13be602597fbe94ee 100644 (file)
--- a/gcc/cp/ChangeLog.omp
+++ b/gcc/cp/ChangeLog.omp
@@ -1,3 +1,8 @@
+2021-02-01  Chung-Lin Tang  <cltang@codesourcery.com>
+
+       * semantics.cc (finish_omp_clauses):  Adjust to allow duplicate
+       mapped variables for OpenMP.
+
 2020-08-19  Sandra Loosemore  <sandra@codesourcery.com>
 
        Add a "combined" flag for "acc kernels loop" etc directives.

diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 2c0e1c7eaa0f94072ef572b317655481ba1c6fef..daef4fb581e97ed801759550536108ebe66c9cd5 100644 (file)
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -8271,7 +8271,8 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
                bitmap_set_bit (&map_firstprivate_head, DECL_UID (t));
            }
          else if (bitmap_bit_p (&map_head, DECL_UID (t))
-                  && !bitmap_bit_p (&map_field_head, DECL_UID (t)))
+                  && !bitmap_bit_p (&map_field_head, DECL_UID (t))
+                  && ort != C_ORT_OMP)
            {
              if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_MAP)
                error_at (OMP_CLAUSE_LOCATION (c),

diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc
index b28d2b81493a708406421746fdc87a3e82d41b33..bac635fb58c06b014f5ec6c128f1b8671b104dbd 100644 (file)
--- a/gcc/omp-low.cc
+++ b/gcc/omp-low.cc
@@ -773,25 +773,29 @@ build_sender_ref (tree var, omp_context *ctx)
   return build_sender_ref ((splay_tree_key) var, ctx);
 }
 
-/* Add a new field for VAR inside the structure CTX->SENDER_DECL.  If
-   BASE_POINTERS_RESTRICT, declare the field with restrict.  */
-
 static void
 install_var_field (tree var, bool by_ref, int mask, omp_context *ctx,
+                  tree key_expr = NULL_TREE,
                   bool base_pointers_restrict = false)
 {
   tree field, type, sfield = NULL_TREE;
   splay_tree_key key = (splay_tree_key) var;
 
-  if ((mask & 16) != 0)
-    {
-      key = (splay_tree_key) &DECL_NAME (var);
-      gcc_checking_assert (key != (splay_tree_key) var);
-    }
-  if ((mask & 8) != 0)
+  if (key_expr)
+    /* Allow user to explicitly set the expression used as the key.  */
+    key = (splay_tree_key) key_expr;
+  else
     {
-      key = (splay_tree_key) &DECL_UID (var);
-      gcc_checking_assert (key != (splay_tree_key) var);
+      if ((mask & 16) != 0)
+       {
+         key = (splay_tree_key) &DECL_NAME (var);
+         gcc_checking_assert (key != (splay_tree_key) var);
+       }
+      if ((mask & 8) != 0)
+       {
+         key = (splay_tree_key) &DECL_UID (var);
+         gcc_checking_assert (key != (splay_tree_key) var);
+       }
     }
   gcc_assert ((mask & 1) == 0
              || !splay_tree_lookup (ctx->field_map, key));
@@ -1488,8 +1492,13 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
            {
              if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE)
                {
+                 /* OpenACC firstprivate clauses are later processed with same
+                    code path as map clauses in lower_omp_target, so follow
+                    the same convention of using the whole clause expression
+                    as splay-tree key.  */
+                 tree k = (is_oacc_parallel_or_serial (ctx) ? c : NULL_TREE);
                  by_ref = !omp_privatize_by_reference (decl);
-                 install_var_field (decl, by_ref, 3, ctx);
+                 install_var_field (decl, by_ref, 3, ctx, k);
                }
              else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_HAS_DEVICE_ADDR)
                {
@@ -1778,7 +1787,7 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
                  t = TREE_TYPE (t);
                }
 
-             install_var_field (array_decl, by_ref, 3, ctx);
+             install_var_field (array_decl, by_ref, 3, ctx, c);
              install_var_local (array_decl, ctx);
              break;
            }
@@ -1792,7 +1801,7 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
                  gcc_assert (TREE_CODE (decl2) == INDIRECT_REF);
                  decl2 = TREE_OPERAND (decl2, 0);
                  gcc_assert (DECL_P (decl2));
-                 install_var_field (decl2, true, 3, ctx);
+                 install_var_field (decl2, true, 3, ctx, c);
                  install_var_local (decl2, ctx);
                  install_var_local (decl, ctx);
                }
@@ -1802,9 +1811,9 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
                      && OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER
                      && !OMP_CLAUSE_MAP_ZERO_BIAS_ARRAY_SECTION (c)
                      && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
-                   install_var_field (decl, true, 7, ctx);
+                   install_var_field (decl, true, 7, ctx, c);
                  else
-                   install_var_field (decl, true, 3, ctx,
+                   install_var_field (decl, true, 3, ctx, c,
                                       base_pointers_restrict);
                  if (is_gimple_omp_offloaded (ctx->stmt)
                      && !(is_gimple_omp_oacc (ctx->stmt)
@@ -1840,7 +1849,7 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
                                  FIELD_DECL, NULL_TREE, ptr_type_node);
                  SET_DECL_ALIGN (field, TYPE_ALIGN (ptr_type_node));
                  insert_field_into_struct (ctx->record_type, field);
-                 splay_tree_insert (ctx->field_map, (splay_tree_key) decl,
+                 splay_tree_insert (ctx->field_map, (splay_tree_key) c,
                                     (splay_tree_value) field);
                }
            }
@@ -4738,8 +4747,19 @@ maybe_lookup_field_in_outer_ctx (tree decl, omp_context *ctx)
   omp_context *up;
 
   for (up = ctx->outer; up; up = up->outer)
-    if (maybe_lookup_field (decl, up))
-      return true;
+    {
+      for (tree c = gimple_omp_target_clauses (up->stmt);
+          c != NULL_TREE; c = OMP_CLAUSE_CHAIN (c))
+       if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
+            || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_TO
+            || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FROM
+            || (is_oacc_parallel_or_serial (up)
+                && OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE))
+           && OMP_CLAUSE_DECL (c) == decl)
+         return true;
+      if (maybe_lookup_field (decl, up))
+       return true;
+    }
 
   return false;
 }
@@ -7736,6 +7756,7 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
        gcc_checking_assert (!is_oacc_kernels_decomposed_part (ctx));
 
        tree orig = OMP_CLAUSE_DECL (c);
+       tree orig_clause;
        tree var;
        tree ref_to_res = NULL_TREE;
        tree incoming, outgoing;
@@ -7818,8 +7839,18 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
          do_lookup:
            /* This is the outermost construct with this reduction,
               see if there's a mapping for it.  */
-           if (gimple_code (outer->stmt) == GIMPLE_OMP_TARGET
-               && (maybe_lookup_field (orig, outer) || is_fpp) && !is_private)
+           orig_clause = NULL_TREE;
+           if (gimple_code (outer->stmt) == GIMPLE_OMP_TARGET)
+             for (tree cls = gimple_omp_target_clauses (outer->stmt);
+                  cls; cls = OMP_CLAUSE_CHAIN (cls))
+               if (OMP_CLAUSE_CODE (cls) == OMP_CLAUSE_MAP
+                   && orig == OMP_CLAUSE_DECL (cls)
+                   && maybe_lookup_field (cls, outer))
+                 {
+                   orig_clause = cls;
+                   break;
+                 }
+           if ((orig_clause != NULL_TREE || is_fpp) && !is_private)
              {
                tree type = TREE_TYPE (var);
 
@@ -7831,7 +7862,7 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
                  }
                else
                  {
-                   ref_to_res = build_receiver_ref (orig, false, outer);
+                   ref_to_res = build_receiver_ref (orig_clause, false, outer);
                    if (omp_privatize_by_reference (orig))
                      ref_to_res = build_simple_mem_ref (ref_to_res);
                  }
@@ -13156,7 +13187,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
            continue;
          }
 
-       if (!maybe_lookup_field (var, ctx))
+       if (!maybe_lookup_field (c, ctx))
          continue;
 
        /* Don't remap compute constructs' reduction variables, because the
@@ -13176,7 +13207,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
               && TREE_CODE (var_type) != ARRAY_TYPE
               ? false : true);
 
-           x = build_receiver_ref (var, rcv_by_ref, ctx);
+           x = build_receiver_ref (c, rcv_by_ref, ctx);
 
            if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
                && (FLOAT_TYPE_P (inner_type)
@@ -13430,7 +13461,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
                  }
                else
                  {
-                   tree x = build_sender_ref (ovar, ctx);
+                   tree x = build_sender_ref (c, ctx);
                    tree v = ovar;
                    if (in_reduction_clauses
                        && OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
@@ -13478,7 +13509,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
                    gcc_assert (DECL_P (ovar2));
                    ovar = ovar2;
                  }
-               if (!maybe_lookup_field (ovar, ctx)
+               if (!maybe_lookup_field (c, ctx)
                    && !(OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
                         && (OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_ATTACH
                             || OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_DETACH)))
@@ -13528,7 +13559,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
              }
            else if (nc)
              {
-               x = build_sender_ref (ovar, ctx);
+               x = build_sender_ref (nc, ctx);
 
                if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
                    && OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER
@@ -14351,7 +14382,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
                    new_var = decl2;
                    type = TREE_TYPE (new_var);
                  }
-               x = build_receiver_ref (OMP_CLAUSE_DECL (prev), false, ctx);
+               x = build_receiver_ref (prev, false, ctx);
                x = fold_convert_loc (clause_loc, type, x);
                if (!integer_zerop (OMP_CLAUSE_SIZE (c)))
                  {

diff --git a/gcc/testsuite/ChangeLog.omp b/gcc/testsuite/ChangeLog.omp
index a810edff4b5ca0a7c5b3b5f6a6586f1e10a0ae67..f298d9f838ecd6c2bacd0069b31e1ac7e2c9e9b5 100644 (file)
--- a/gcc/testsuite/ChangeLog.omp
+++ b/gcc/testsuite/ChangeLog.omp
@@ -1,3 +1,7 @@
+2021-02-01  Chung-Lin Tang  <cltang@codesourcery.com>
+
+       * c-c++-common/gomp/clauses-2.c: Adjust testcase.
+
 2020-08-30  Sandra Loosemore  <sandra@codesourcery.com>
 
        * c-c++-common/goacc/kernels-loop-annotation-21.c: New.

diff --git a/gcc/testsuite/c-c++-common/gomp/clauses-2.c b/gcc/testsuite/c-c++-common/gomp/clauses-2.c
index bbc8fb4e32bf81267293de248057c42558f88312..f1ce73993108b91096325546d8bc0db9781485f0 100644 (file)
--- a/gcc/testsuite/c-c++-common/gomp/clauses-2.c
+++ b/gcc/testsuite/c-c++-common/gomp/clauses-2.c
@@ -15,7 +15,7 @@ foo (int *p, int q, struct S t, int i, int j, int k, int l)
     bar (p);
   #pragma omp target map (p) , map (p[0])
     bar (p);
-  #pragma omp target map (q) map (q) /* { dg-error "appears more than once in map clauses" } */
+  #pragma omp target map (q) map (q)
     bar (&q);
   #pragma omp target map (p[0]) map (p[0]) /* { dg-error "appears more than once in data clauses" } */
     bar (p);