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/c/ChangeLog:

	* c-typeck.c (c_finish_omp_clauses): Adjust to allow duplicate
	mapped variables for OpenMP.

gcc/cp/ChangeLog:

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

gcc/ChangeLog:

	* omp-low.c (install_parm_decl): Add new 'tree key_expr' parameter.
	Use key_expr as splay-tree key instead of var itself.
	(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/c/c-typeck.c b/gcc/c/c-typeck.c
index 847b8032061c032cdac51f2dcb75b48dd6686117..efcd1e1620f71af9516f88d1ce3ad7b0f7646e21 100644 (file)
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -14884,8 +14884,8 @@ c_finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
                bitmap_set_bit (&generic_head, DECL_UID (t));
            }
          else if (bitmap_bit_p (&map_head, DECL_UID (t))
-                  && (ort != C_ORT_OMP
-                      || !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/cp/semantics.c b/gcc/cp/semantics.c
index 164f7c396e039cf02d9942831df9aea148544770..e59df896b25c63fc486ba8356af463be9a7bdf7b 100644 (file)
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -7896,7 +7896,8 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
                bitmap_set_bit (&generic_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.c b/gcc/omp-low.c
index 3c7f8f986ded3aff5837b40d5b51d3d7fd2596c6..935dbd6c6dcff72333928bb4b130d6b759a94f9a 100644 (file)
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -770,25 +770,29 @@ 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));
@@ -1447,7 +1451,14 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
              && is_gimple_omp_offloaded (ctx->stmt))
            {
              if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE)
-               install_var_field (decl, !omp_is_reference (decl), 3, ctx);
+               {
+                 /* 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);
+                 install_var_field (decl, !omp_is_reference (decl), 3, ctx, k);
+               }
              else if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
                install_var_field (decl, true, 3, ctx);
              else
@@ -1678,7 +1689,7 @@ 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;
            }
@@ -1692,7 +1703,7 @@ 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);
                }
@@ -1702,9 +1713,9 @@ 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)
                      && !OMP_CLAUSE_MAP_IN_REDUCTION (c))
@@ -1739,7 +1750,7 @@ 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);
                }
            }
@@ -4507,8 +4518,19 @@ 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;
 }
@@ -7392,6 +7414,7 @@ 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;
@@ -7474,8 +7497,18 @@ 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);
 
@@ -7487,7 +7520,7 @@ 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_is_reference (orig))
                      ref_to_res = build_simple_mem_ref (ref_to_res);
                  }
@@ -12491,7 +12524,7 @@ 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
@@ -12509,7 +12542,7 @@ 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)
@@ -12755,7 +12788,7 @@ 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
                      = build_fold_addr_expr_with_type (ovar, ptr_type_node);
                    gimplify_assign (x, v, &ilist);
@@ -12773,7 +12806,7 @@ 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)))
@@ -12797,7 +12830,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
            else if (nc)
              {
                var = lookup_decl_in_outer_ctx (ovar, ctx);
-               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
@@ -13564,7 +13597,7 @@ 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/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);