OpenMP/Fortran: Add support for OpenMP 5.2 linear clause syntax

Fortran part to C/C++
commit r13-1002-g03b71406323ddc065b1d7837d8b43b17e4b048b5

gcc/fortran/ChangeLog:

	* gfortran.h (gfc_omp_namelist): Update by creating 'linear' struct,
	move 'linear_op' as 'op' to id and add 'old_modifier' to it.
	* dump-parse-tree.cc (show_omp_namelist): Update accordingly.
	* module.cc (mio_omp_declare_simd): Likewise.
	* trans-openmp.cc (gfc_trans_omp_clauses): Likewise.
	* openmp.cc (resolve_omp_clauses): Likewise; accept new-style
	'val' modifier with do/simd.
	(gfc_match_omp_clauses): Handle OpenMP 5.2 linear clause syntax.

libgomp/ChangeLog:

	* libgomp.texi (OpenMP 5.2): Mark linear-clause change as 'Y'.

gcc/testsuite/ChangeLog:

	* c-c++-common/gomp/linear-4.c: New test.
	* gfortran.dg/gomp/linear-2.f90: New test.
	* gfortran.dg/gomp/linear-3.f90: New test.
	* gfortran.dg/gomp/linear-4.f90: New test.
	* gfortran.dg/gomp/linear-5.f90: New test.
	* gfortran.dg/gomp/linear-6.f90: New test.
	* gfortran.dg/gomp/linear-7.f90: New test.
	* gfortran.dg/gomp/linear-8.f90: New test.

Co-authored-by: Jakub Jelinek <jakub@redhat.com>

5 files changed, 157 insertions, 29 deletions

diff --git a/gcc/fortran/dump-parse-tree.cc b/gcc/fortran/dump-parse-tree.cc
index 85c0b98..5352008 100644
--- a/gcc/fortran/dump-parse-tree.cc
+++ b/gcc/fortran/dump-parse-tree.cc
@@ -1421,8 +1421,8 @@ show_omp_namelist (int list_type, gfc_omp_namelist *n)
 	  case OMP_MAP_RELEASE: fputs ("release:", dumpfile); break;
 	  default: break;
 	  }
-      else if (list_type == OMP_LIST_LINEAR)
-	switch (n->u.linear_op)
+      else if (list_type == OMP_LIST_LINEAR && n->u.linear.old_modifier)
+	switch (n->u.linear.op)
 	  {
 	  case OMP_LINEAR_REF: fputs ("ref(", dumpfile); break;
 	  case OMP_LINEAR_VAL: fputs ("val(", dumpfile); break;
@@ -1430,7 +1430,7 @@ show_omp_namelist (int list_type, gfc_omp_namelist *n)
 	  default: break;
 	  }
       fprintf (dumpfile, "%s", n->sym ? n->sym->name : "omp_all_memory");
-      if (list_type == OMP_LIST_LINEAR && n->u.linear_op != OMP_LINEAR_DEFAULT)
+      if (list_type == OMP_LIST_LINEAR && n->u.linear.op != OMP_LINEAR_DEFAULT)
 	fputc (')', dumpfile);
       if (n->expr)
 	{
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 463d969..696aadd 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -1345,7 +1345,11 @@ typedef struct gfc_omp_namelist
       gfc_omp_reduction_op reduction_op;
       gfc_omp_depend_op depend_op;
       gfc_omp_map_op map_op;
-      gfc_omp_linear_op linear_op;
+      struct
+	{
+	  ENUM_BITFIELD (gfc_omp_linear_op) op:4;
+	  bool old_modifier;
+	} linear;
       struct gfc_common_head *common;
       bool lastprivate_conditional;
     } u;
diff --git a/gcc/fortran/module.cc b/gcc/fortran/module.cc
index 85aa153..5ddabdc 100644
--- a/gcc/fortran/module.cc
+++ b/gcc/fortran/module.cc
@@ -4383,10 +4383,10 @@ mio_omp_declare_simd (gfc_namespace *ns, gfc_omp_declare_simd **odsp)
 	    }
 	  for (n = ods->clauses->lists[OMP_LIST_LINEAR]; n; n = n->next)
 	    {
-	      if (n->u.linear_op == OMP_LINEAR_DEFAULT)
+	      if (n->u.linear.op == OMP_LINEAR_DEFAULT)
 		mio_name (4, omp_declare_simd_clauses);
 	      else
-		mio_name (32 + n->u.linear_op, omp_declare_simd_clauses);
+		mio_name (32 + n->u.linear.op, omp_declare_simd_clauses);
 	      mio_symbol_ref (&n->sym);
 	      mio_expr (&n->expr);
 	    }
@@ -4438,7 +4438,7 @@ mio_omp_declare_simd (gfc_namespace *ns, gfc_omp_declare_simd **odsp)
 	    case 34:
 	    case 35:
 	      *ptrs[1] = n = gfc_get_omp_namelist ();
-	      n->u.linear_op = (enum gfc_omp_linear_op) (t - 32);
+	      n->u.linear.op = (enum gfc_omp_linear_op) (t - 32);
 	      t = 4;
 	      goto finish_namelist;
 	    }
diff --git a/gcc/fortran/openmp.cc b/gcc/fortran/openmp.cc
index 51b429a..bd4ff25 100644
--- a/gcc/fortran/openmp.cc
+++ b/gcc/fortran/openmp.cc
@@ -2324,6 +2324,7 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
 	  if ((mask & OMP_CLAUSE_LINEAR)
 	      && gfc_match ("linear (") == MATCH_YES)
 	    {
+	      bool old_linear_modifier = false;
 	      gfc_omp_linear_op linear_op = OMP_LINEAR_DEFAULT;
 	      gfc_expr *step = NULL;
 
@@ -2331,17 +2332,26 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
 					       &c->lists[OMP_LIST_LINEAR],
 					       false, NULL, &head)
 		  == MATCH_YES)
-		linear_op = OMP_LINEAR_REF;
+		{
+		  linear_op = OMP_LINEAR_REF;
+		  old_linear_modifier = true;
+		}
 	      else if (gfc_match_omp_variable_list (" val (",
 						    &c->lists[OMP_LIST_LINEAR],
 						    false, NULL, &head)
 		       == MATCH_YES)
-		linear_op = OMP_LINEAR_VAL;
+		{
+		  linear_op = OMP_LINEAR_VAL;
+		  old_linear_modifier = true;
+		}
 	      else if (gfc_match_omp_variable_list (" uval (",
 						    &c->lists[OMP_LIST_LINEAR],
 						    false, NULL, &head)
 		       == MATCH_YES)
-		linear_op = OMP_LINEAR_UVAL;
+		{
+		  linear_op = OMP_LINEAR_UVAL;
+		  old_linear_modifier = true;
+		}
 	      else if (gfc_match_omp_variable_list ("",
 						    &c->lists[OMP_LIST_LINEAR],
 						    false, &end_colon, &head)
@@ -2364,14 +2374,114 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
 		      break;
 		    }
 		}
-	      if (end_colon && gfc_match (" %e )", &step) != MATCH_YES)
+	      gfc_gobble_whitespace ();
+	      if (old_linear_modifier && end_colon)
 		{
-		  gfc_free_omp_namelist (*head, false);
-		  gfc_current_locus = old_loc;
-		  *head = NULL;
-		  break;
+		  if (gfc_match (" %e )", &step) != MATCH_YES)
+		    {
+		      gfc_free_omp_namelist (*head, false);
+		      gfc_current_locus = old_loc;
+		      *head = NULL;
+		      goto error;
+		    }
 		}
-	      else if (!end_colon)
+	      else if (end_colon)
+		{
+		  bool has_error = false;
+		  bool has_modifiers = false;
+		  bool has_step = false;
+		  bool duplicate_step = false;
+		  bool duplicate_mod = false;
+		  while (true)
+		    {
+		      old_loc = gfc_current_locus;
+		      bool close_paren = gfc_match ("val )") == MATCH_YES;
+		      if (close_paren || gfc_match ("val , ") == MATCH_YES)
+			{
+			  if (linear_op != OMP_LINEAR_DEFAULT)
+			    {
+			      duplicate_mod = true;
+			      break;
+			    }
+			  linear_op = OMP_LINEAR_VAL;
+			  has_modifiers = true;
+			  if (close_paren)
+			    break;
+			  continue;
+			}
+		      close_paren = gfc_match ("uval )") == MATCH_YES;
+		      if (close_paren || gfc_match ("uval , ") == MATCH_YES)
+			{
+			  if (linear_op != OMP_LINEAR_DEFAULT)
+			    {
+			      duplicate_mod = true;
+			      break;
+			    }
+			  linear_op = OMP_LINEAR_UVAL;
+			  has_modifiers = true;
+			  if (close_paren)
+			    break;
+			  continue;
+			}
+		      close_paren = gfc_match ("ref )") == MATCH_YES;
+		      if (close_paren || gfc_match ("ref , ") == MATCH_YES)
+			{
+			  if (linear_op != OMP_LINEAR_DEFAULT)
+			    {
+			      duplicate_mod = true;
+			      break;
+			    }
+			  linear_op = OMP_LINEAR_REF;
+			  has_modifiers = true;
+			  if (close_paren)
+			    break;
+			  continue;
+			}
+		      close_paren = (gfc_match ("step ( %e ) )", &step)
+				     == MATCH_YES);
+		      if (close_paren
+			  || gfc_match ("step ( %e ) , ", &step) == MATCH_YES)
+			{
+			  if (has_step)
+			    {
+			      duplicate_step = true;
+			      break;
+			    }
+			  has_modifiers = has_step = true;
+			  if (close_paren)
+			    break;
+			  continue;
+			}
+		      if (!has_modifiers
+			  && gfc_match ("%e )", &step) == MATCH_YES)
+			{
+			  if ((step->expr_type == EXPR_FUNCTION
+				|| step->expr_type == EXPR_VARIABLE)
+			      && strcmp (step->symtree->name, "step") == 0)
+			    {
+			      gfc_current_locus = old_loc;
+			      gfc_match ("step (");
+			      has_error = true;
+			    }
+			  break;
+			}
+		      has_error = true;
+		      break;
+		    }
+		  if (duplicate_mod || duplicate_step)
+		    {
+		      gfc_error ("Multiple %qs modifiers specified at %C",
+				 duplicate_mod ? "linear" : "step");
+		      has_error = true;
+		    }
+		  if (has_error)
+		    {
+		      gfc_free_omp_namelist (*head, false);
+		      *head = NULL;
+		      goto error;
+		    }
+		}
+	      else
 		{
 		  step = gfc_get_constant_expr (BT_INTEGER,
 						gfc_default_integer_kind,
@@ -2379,9 +2489,12 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
 		  mpz_set_si (step->value.integer, 1);
 		}
 	      (*head)->expr = step;
-	      if (linear_op != OMP_LINEAR_DEFAULT)
+	      if (linear_op != OMP_LINEAR_DEFAULT || old_linear_modifier)
 		for (gfc_omp_namelist *n = *head; n; n = n->next)
-		  n->u.linear_op = linear_op;
+		  {
+		    n->u.linear.op = linear_op;
+		    n->u.linear.old_modifier = old_linear_modifier;
+		  }
 	      continue;
 	    }
 	  if ((mask & OMP_CLAUSE_LINK)
@@ -7439,28 +7552,38 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 		    break;
 		  case OMP_LIST_LINEAR:
 		    if (code
-			&& n->u.linear_op != OMP_LINEAR_DEFAULT
-			&& n->u.linear_op != linear_op)
+			&& n->u.linear.op != OMP_LINEAR_DEFAULT
+			&& n->u.linear.op != linear_op)
 		      {
-			gfc_error ("LINEAR clause modifier used on DO or SIMD"
-				   " construct at %L", &n->where);
-			linear_op = n->u.linear_op;
+			if (n->u.linear.old_modifier)
+			  {
+			    gfc_error ("LINEAR clause modifier used on DO or "
+				       "SIMD construct at %L", &n->where);
+			    linear_op = n->u.linear.op;
+			  }
+			else if (n->u.linear.op != OMP_LINEAR_VAL)
+			  {
+			    gfc_error ("LINEAR clause modifier other than VAL "
+				       "used on DO or SIMD construct at %L",
+				       &n->where);
+			    linear_op = n->u.linear.op;
+			  }
 		      }
 		    else if (omp_clauses->orderedc)
 		      gfc_error ("LINEAR clause specified together with "
 				 "ORDERED clause with argument at %L",
 				 &n->where);
-		    else if (n->u.linear_op != OMP_LINEAR_REF
+		    else if (n->u.linear.op != OMP_LINEAR_REF
 			     && n->sym->ts.type != BT_INTEGER)
 		      gfc_error ("LINEAR variable %qs must be INTEGER "
 				 "at %L", n->sym->name, &n->where);
-		    else if ((n->u.linear_op == OMP_LINEAR_REF
-			      || n->u.linear_op == OMP_LINEAR_UVAL)
+		    else if ((n->u.linear.op == OMP_LINEAR_REF
+			      || n->u.linear.op == OMP_LINEAR_UVAL)
 			     && n->sym->attr.value)
 		      gfc_error ("LINEAR dummy argument %qs with VALUE "
 				 "attribute with %s modifier at %L",
 				 n->sym->name,
-				 n->u.linear_op == OMP_LINEAR_REF
+				 n->u.linear.op == OMP_LINEAR_REF
 				 ? "REF" : "UVAL", &n->where);
 		    else if (n->expr)
 		      {
diff --git a/gcc/fortran/trans-openmp.cc b/gcc/fortran/trans-openmp.cc
index c6a584d..de27ed5 100644
--- a/gcc/fortran/trans-openmp.cc
+++ b/gcc/fortran/trans-openmp.cc
@@ -2751,7 +2751,7 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 						      OMP_CLAUSE_LINEAR);
 			OMP_CLAUSE_DECL (node) = t;
 			omp_clause_linear_kind kind;
-			switch (n->u.linear_op)
+			switch (n->u.linear.op)
 			  {
 			  case OMP_LINEAR_DEFAULT:
 			    kind = OMP_CLAUSE_LINEAR_DEFAULT;
@@ -2769,7 +2769,8 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			    gcc_unreachable ();
 			  }
 			OMP_CLAUSE_LINEAR_KIND (node) = kind;
-			OMP_CLAUSE_LINEAR_OLD_LINEAR_MODIFIER (node) = 1;
+			OMP_CLAUSE_LINEAR_OLD_LINEAR_MODIFIER (node)
+			  = n->u.linear.old_modifier;
 			if (last_step_expr && last_step == NULL_TREE)
 			  {
 			    if (!declare_simd)