openmp: Add support for OpenMP 5.1 masked construct

This construct has been introduced as a replacement for master
construct, but unlike that construct is slightly more general,
has an optional clause which allows to choose which thread
will be the one running the region, it can be some other thread
than the master (primary) thread with number 0, or it could be no
threads or multiple threads (then of course one needs to be careful
about data races).

It is way too early to deprecate the master construct though, we don't
even have OpenMP 5.0 fully implemented, it has been deprecated in 5.1,
will be also in 5.2 and removed in 6.0.  But even then it will likely
be a good idea to just -Wdeprecated warn about it and still accept it.

The patch also contains something I should have done much earlier,
for clauses that accept some integral expression where we only care
about the value, forces during gimplification that value into
either a min invariant (as before), SSA_NAME or a fresh temporary,
but never e.g. a user VAR_DECL, so that for those clauses we don't
need to worry about adjusting it.

2021-08-12  Jakub Jelinek  <jakub@redhat.com>

gcc/
	* tree.def (OMP_MASKED): New tree code.
	* tree-core.h (enum omp_clause_code): Add OMP_CLAUSE_FILTER.
	* tree.h (OMP_MASKED_BODY, OMP_MASKED_CLAUSES, OMP_MASKED_COMBINED,
	OMP_CLAUSE_FILTER_EXPR): Define.
	* tree.c (omp_clause_num_ops): Add OMP_CLAUSE_FILTER entry.
	(omp_clause_code_name): Likewise.
	(walk_tree_1): Handle OMP_CLAUSE_FILTER.
	* tree-nested.c (convert_nonlocal_omp_clauses,
	convert_local_omp_clauses): Handle OMP_CLAUSE_FILTER.
	(convert_nonlocal_reference_stmt, convert_local_reference_stmt,
	convert_gimple_call): Handle GIMPLE_OMP_MASTER.
	* tree-pretty-print.c (dump_omp_clause): Handle OMP_CLAUSE_FILTER.
	(dump_generic_node): Handle OMP_MASTER.
	* gimple.def (GIMPLE_OMP_MASKED): New gimple code.
	* gimple.c (gimple_build_omp_masked): New function.
	(gimple_copy): Handle GIMPLE_OMP_MASKED.
	* gimple.h (gimple_build_omp_masked): Declare.
	(gimple_has_substatements): Handle GIMPLE_OMP_MASKED.
	(gimple_omp_masked_clauses, gimple_omp_masked_clauses_ptr,
	gimple_omp_masked_set_clauses): New inline functions.
	(CASE_GIMPLE_OMP): Add GIMPLE_OMP_MASKED.
	* gimple-pretty-print.c (dump_gimple_omp_masked): New function.
	(pp_gimple_stmt_1): Handle GIMPLE_OMP_MASKED.
	* gimple-walk.c (walk_gimple_stmt): Likewise.
	* gimple-low.c (lower_stmt): Likewise.
	* gimplify.c (is_gimple_stmt): Handle OMP_MASTER.
	(gimplify_scan_omp_clauses): Handle OMP_CLAUSE_FILTER.  For clauses
	that take one expression rather than decl or constant, force
	gimplification of that into a SSA_NAME or temporary unless min
	invariant.
	(gimplify_adjust_omp_clauses): Handle OMP_CLAUSE_FILTER.
	(gimplify_expr): Handle OMP_MASKED.
	* tree-inline.c (remap_gimple_stmt): Handle GIMPLE_OMP_MASKED.
	(estimate_num_insns): Likewise.
	* omp-low.c (scan_sharing_clauses): Handle OMP_CLAUSE_FILTER.
	(check_omp_nesting_restrictions): Handle GIMPLE_OMP_MASKED.  Adjust
	diagnostics for existence of masked construct.
	(scan_omp_1_stmt, lower_omp_master, lower_omp_1, diagnose_sb_1,
	diagnose_sb_2): Handle GIMPLE_OMP_MASKED.
	* omp-expand.c (expand_omp_synch, expand_omp, omp_make_gimple_edges):
	Likewise.
gcc/c-family/
	* c-pragma.h (enum pragma_kind): Add PRAGMA_OMP_MASKED.
	(enum pragma_omp_clause): Add PRAGMA_OMP_CLAUSE_FILTER.
	* c-pragma.c (omp_pragmas_simd): Add masked construct.
	* c-common.h (enum c_omp_clause_split): Add C_OMP_CLAUSE_SPLIT_MASKED
	enumerator.
	(c_finish_omp_masked): Declare.
	* c-omp.c (c_finish_omp_masked): New function.
	(c_omp_split_clauses): Handle combined masked constructs.
gcc/c/
	* c-parser.c (c_parser_omp_clause_name): Parse filter clause name.
	(c_parser_omp_clause_filter): New function.
	(c_parser_omp_all_clauses): Handle PRAGMA_OMP_CLAUSE_FILTER.
	(OMP_MASKED_CLAUSE_MASK): Define.
	(c_parser_omp_masked): New function.
	(c_parser_omp_parallel): Handle parallel masked.
	(c_parser_omp_construct): Handle PRAGMA_OMP_MASKED.
	* c-typeck.c (c_finish_omp_clauses): Handle OMP_CLAUSE_FILTER.
gcc/cp/
	* parser.c (cp_parser_omp_clause_name): Parse filter clause name.
	(cp_parser_omp_clause_filter): New function.
	(cp_parser_omp_all_clauses): Handle PRAGMA_OMP_CLAUSE_FILTER.
	(OMP_MASKED_CLAUSE_MASK): Define.
	(cp_parser_omp_masked): New function.
	(cp_parser_omp_parallel): Handle parallel masked.
	(cp_parser_omp_construct, cp_parser_pragma): Handle PRAGMA_OMP_MASKED.
	* semantics.c (finish_omp_clauses): Handle OMP_CLAUSE_FILTER.
	* pt.c (tsubst_omp_clauses): Likewise.
	(tsubst_expr): Handle OMP_MASKED.
gcc/testsuite/
	* c-c++-common/gomp/clauses-1.c (bar): Add tests for combined masked
	constructs with clauses.
	* c-c++-common/gomp/clauses-5.c (foo): Add testcase for filter clause.
	* c-c++-common/gomp/clause-dups-1.c (f1): Likewise.
	* c-c++-common/gomp/masked-1.c: New test.
	* c-c++-common/gomp/masked-2.c: New test.
	* c-c++-common/gomp/masked-combined-1.c: New test.
	* c-c++-common/gomp/masked-combined-2.c: New test.
	* c-c++-common/goacc/uninit-if-clause.c: Remove xfails.
	* g++.dg/gomp/block-11.C: New test.
	* g++.dg/gomp/tpl-masked-1.C: New test.
	* g++.dg/gomp/attrs-1.C (bar): Add tests for masked construct and
	combined masked constructs with clauses in attribute syntax.
	* g++.dg/gomp/attrs-2.C (bar): Likewise.
	* gcc.dg/gomp/nesting-1.c (f1, f2): Add tests for masked construct
	nesting.
	* gfortran.dg/goacc/host_data-tree.f95: Allow also SSA_NAMEs in if
	clause.
	* gfortran.dg/goacc/kernels-tree.f95: Likewise.
libgomp/
	* testsuite/libgomp.c-c++-common/masked-1.c: New test.

1 files changed, 140 insertions, 2 deletions

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index b7fe4b4..edb69ae 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -36004,7 +36004,9 @@ cp_parser_omp_clause_name (cp_parser *parser)
 	    result = PRAGMA_OMP_CLAUSE_DIST_SCHEDULE;
 	  break;
 	case 'f':
-	  if (!strcmp ("final", p))
+	  if (!strcmp ("filter", p))
+	    result = PRAGMA_OMP_CLAUSE_FILTER;
+	  else if (!strcmp ("final", p))
 	    result = PRAGMA_OMP_CLAUSE_FINAL;
 	  else if (!strcmp ("finalize", p))
 	    result = PRAGMA_OACC_CLAUSE_FINALIZE;
@@ -37340,6 +37342,34 @@ cp_parser_omp_clause_hint (cp_parser *parser, tree list, location_t location)
   return c;
 }
 
+/* OpenMP 5.1:
+   filter ( integer-expression ) */
+
+static tree
+cp_parser_omp_clause_filter (cp_parser *parser, tree list, location_t location)
+{
+  tree t, c;
+
+  matching_parens parens;
+  if (!parens.require_open (parser))
+    return list;
+
+  t = cp_parser_assignment_expression (parser);
+
+  if (t == error_mark_node
+      || !parens.require_close (parser))
+    cp_parser_skip_to_closing_parenthesis (parser, /*recovering=*/true,
+					   /*or_comma=*/false,
+					   /*consume_paren=*/true);
+  check_no_duplicate_clause (list, OMP_CLAUSE_FILTER, "filter", location);
+
+  c = build_omp_clause (location, OMP_CLAUSE_FILTER);
+  OMP_CLAUSE_FILTER_EXPR (c) = t;
+  OMP_CLAUSE_CHAIN (c) = list;
+
+  return c;
+}
+
 /* OpenMP 4.5:
    defaultmap ( tofrom : scalar )
 
@@ -39449,6 +39479,11 @@ cp_parser_omp_all_clauses (cp_parser *parser, omp_clause_mask mask,
 						  token->location, false);
 	  c_name = "default";
 	  break;
+	case PRAGMA_OMP_CLAUSE_FILTER:
+	  clauses = cp_parser_omp_clause_filter (parser, clauses,
+						 token->location);
+	  c_name = "filter";
+	  break;
 	case PRAGMA_OMP_CLAUSE_FINAL:
 	  clauses = cp_parser_omp_clause_final (parser, clauses, token->location);
 	  c_name = "final";
@@ -41985,6 +42020,73 @@ cp_parser_omp_master (cp_parser *parser, cp_token *pragma_tok,
 			      cp_parser_omp_structured_block (parser, if_p));
 }
 
+/* OpenMP 5.1:
+   # pragma omp masked masked-clauses new-line
+     structured-block  */
+
+#define OMP_MASKED_CLAUSE_MASK					\
+	(OMP_CLAUSE_MASK_1 << PRAGMA_OMP_CLAUSE_FILTER)
+
+static tree
+cp_parser_omp_masked (cp_parser *parser, cp_token *pragma_tok,
+		      char *p_name, omp_clause_mask mask, tree *cclauses,
+		      bool *if_p)
+{
+  tree clauses, sb, ret;
+  unsigned int save;
+  location_t loc = cp_lexer_peek_token (parser->lexer)->location;
+
+  strcat (p_name, " masked");
+  mask |= OMP_MASKED_CLAUSE_MASK;
+
+  if (cp_lexer_next_token_is (parser->lexer, CPP_NAME))
+    {
+      tree id = cp_lexer_peek_token (parser->lexer)->u.value;
+      const char *p = IDENTIFIER_POINTER (id);
+
+      if (strcmp (p, "taskloop") == 0)
+	{
+	  tree cclauses_buf[C_OMP_CLAUSE_SPLIT_COUNT];
+	  if (cclauses == NULL)
+	    cclauses = cclauses_buf;
+
+	  cp_lexer_consume_token (parser->lexer);
+	  if (!flag_openmp)  /* flag_openmp_simd  */
+	    return cp_parser_omp_taskloop (parser, pragma_tok, p_name, mask,
+					   cclauses, if_p);
+	  sb = begin_omp_structured_block ();
+	  save = cp_parser_begin_omp_structured_block (parser);
+	  ret = cp_parser_omp_taskloop (parser, pragma_tok, p_name, mask,
+					cclauses, if_p);
+	  cp_parser_end_omp_structured_block (parser, save);
+	  tree body = finish_omp_structured_block (sb);
+	  if (ret == NULL)
+	    return ret;
+	  ret = c_finish_omp_masked (loc, body,
+				     cclauses[C_OMP_CLAUSE_SPLIT_MASKED]);
+	  OMP_MASKED_COMBINED (ret) = 1;
+	  return ret;
+	}
+    }
+  if (!flag_openmp)  /* flag_openmp_simd  */
+    {
+      cp_parser_skip_to_pragma_eol (parser, pragma_tok);
+      return NULL_TREE;
+    }
+
+  clauses = cp_parser_omp_all_clauses (parser, mask, p_name, pragma_tok,
+				       cclauses == NULL);
+  if (cclauses)
+    {
+      cp_omp_split_clauses (loc, OMP_MASTER, mask, clauses, cclauses);
+      clauses = cclauses[C_OMP_CLAUSE_SPLIT_MASKED];
+    }
+
+  return c_finish_omp_masked (loc,
+			      cp_parser_omp_structured_block (parser, if_p),
+			      clauses);
+}
+
 /* OpenMP 2.5:
    # pragma omp ordered new-line
      structured-block
@@ -42238,7 +42340,37 @@ cp_parser_omp_parallel (cp_parser *parser, cp_token *pragma_tok,
     {
       tree id = cp_lexer_peek_token (parser->lexer)->u.value;
       const char *p = IDENTIFIER_POINTER (id);
-      if (cclauses == NULL && strcmp (p, "master") == 0)
+      if (cclauses == NULL && strcmp (p, "masked") == 0)
+	{
+	  tree cclauses_buf[C_OMP_CLAUSE_SPLIT_COUNT];
+	  cclauses = cclauses_buf;
+
+	  cp_lexer_consume_token (parser->lexer);
+	  if (!flag_openmp)  /* flag_openmp_simd  */
+	    return cp_parser_omp_masked (parser, pragma_tok, p_name, mask,
+					 cclauses, if_p);
+	  block = begin_omp_parallel ();
+	  save = cp_parser_begin_omp_structured_block (parser);
+	  tree ret = cp_parser_omp_masked (parser, pragma_tok, p_name, mask,
+					   cclauses, if_p);
+	  cp_parser_end_omp_structured_block (parser, save);
+	  stmt = finish_omp_parallel (cclauses[C_OMP_CLAUSE_SPLIT_PARALLEL],
+				      block);
+	  if (ret == NULL_TREE)
+	    return ret;
+	  /* masked does have just filter clause, but during gimplification
+	     isn't represented by a gimplification omp context, so for
+	     #pragma omp parallel masked don't set OMP_PARALLEL_COMBINED,
+	     so that
+	     #pragma omp parallel masked
+	     #pragma omp taskloop simd lastprivate (x)
+	     isn't confused with
+	     #pragma omp parallel masked taskloop simd lastprivate (x)  */
+	  if (OMP_MASKED_COMBINED (ret))
+	    OMP_PARALLEL_COMBINED (stmt) = 1;
+	  return stmt;
+	}
+      else if (cclauses == NULL && strcmp (p, "master") == 0)
 	{
 	  tree cclauses_buf[C_OMP_CLAUSE_SPLIT_COUNT];
 	  cclauses = cclauses_buf;
@@ -45824,6 +45956,11 @@ cp_parser_omp_construct (cp_parser *parser, cp_token *pragma_tok, bool *if_p)
       stmt = cp_parser_omp_loop (parser, pragma_tok, p_name, mask, NULL,
 				 if_p);
       break;
+    case PRAGMA_OMP_MASKED:
+      strcpy (p_name, "#pragma omp");
+      stmt = cp_parser_omp_masked (parser, pragma_tok, p_name, mask, NULL,
+				   if_p);
+      break;
     case PRAGMA_OMP_MASTER:
       strcpy (p_name, "#pragma omp");
       stmt = cp_parser_omp_master (parser, pragma_tok, p_name, mask, NULL,
@@ -46464,6 +46601,7 @@ cp_parser_pragma (cp_parser *parser, enum pragma_context context, bool *if_p)
     case PRAGMA_OMP_DISTRIBUTE:
     case PRAGMA_OMP_FOR:
     case PRAGMA_OMP_LOOP:
+    case PRAGMA_OMP_MASKED:
     case PRAGMA_OMP_MASTER:
     case PRAGMA_OMP_PARALLEL:
     case PRAGMA_OMP_SECTIONS: