Add OpenACC 2.6 `serial' construct support

    The `serial' construct (cf. section 2.5.3 of the OpenACC 2.6 standard)
    is equivalent to a `parallel' construct with clauses `num_gangs(1)
    num_workers(1) vector_length(1)' implied.
    These clauses are therefore not supported with the `serial'
    construct. All the remaining clauses accepted with `parallel' are also
    accepted with `serial'.

    The `serial' construct is implemented like `parallel', except for
    hardcoding dimensions rather than taking them from the relevant
    clauses, in `expand_omp_target'.

    Separate codes are used to denote the `serial' construct throughout the
    middle end, even though the mapping of `serial' to an equivalent
    `parallel' construct could have been done in the individual language
    frontends. In particular, this allows to distinguish between compute
    constructs in warnings, error messages, dumps etc.

    2019-11-12  Maciej W. Rozycki  <macro@codesourcery.com>
                Tobias Burnus  <tobias@codesourcery.com>
                Frederik Harwath  <frederik@codesourcery.com>
                Thomas Schwinge  <thomas@codesourcery.com>

    gcc/
    * gimple.h (gf_mask): Add GF_OMP_TARGET_KIND_OACC_SERIAL
    enumeration constant.
    (is_gimple_omp_oacc): Handle GF_OMP_TARGET_KIND_OACC_SERIAL.
    (is_gimple_omp_offloaded): Likewise.
    * gimplify.c (omp_region_type): Add ORT_ACC_SERIAL enumeration
    constant.  Adjust the value of ORT_NONE accordingly.
    (is_gimple_stmt): Handle OACC_SERIAL.
    (oacc_default_clause): Handle ORT_ACC_SERIAL.
    (gomp_needs_data_present): Likewise.
    (gimplify_adjust_omp_clauses): Likewise.
    (gimplify_omp_workshare): Handle OACC_SERIAL.
    (gimplify_expr): Likewise.
    * omp-expand.c (expand_omp_target):
    Handle GF_OMP_TARGET_KIND_OACC_SERIAL.
    (build_omp_regions_1, omp_make_gimple_edges): Likewise.
    * omp-low.c (is_oacc_parallel): Rename function to...
    (is_oacc_parallel_or_serial): ... this.
    Handle GF_OMP_TARGET_KIND_OACC_SERIAL.
    (scan_sharing_clauses): Adjust accordingly.
    (scan_omp_for): Likewise.
    (lower_oacc_head_mark): Likewise.
    (convert_from_firstprivate_int): Likewise.
    (lower_omp_target): Likewise.
    (check_omp_nesting_restrictions): Handle
    GF_OMP_TARGET_KIND_OACC_SERIAL.
    (lower_oacc_reductions): Likewise.
    (lower_omp_target): Likewise.
    * tree.def (OACC_SERIAL): New tree code.
    * tree-pretty-print.c (dump_generic_node): Handle OACC_SERIAL.

    * doc/generic.texi (OpenACC): Document OACC_SERIAL.

    gcc/c-family/
    * c-pragma.h (pragma_kind): Add PRAGMA_OACC_SERIAL enumeration
    constant.
    * c-pragma.c (oacc_pragmas): Add "serial" entry.

    gcc/c/
    * c-parser.c (OACC_SERIAL_CLAUSE_MASK): New macro.
    (c_parser_oacc_kernels_parallel): Rename function to...
    (c_parser_oacc_compute): ... this.  Handle PRAGMA_OACC_SERIAL.
    (c_parser_omp_construct): Update accordingly.

    gcc/cp/
    * constexpr.c (potential_constant_expression_1): Handle
    OACC_SERIAL.
    * parser.c (OACC_SERIAL_CLAUSE_MASK): New macro.
    (cp_parser_oacc_kernels_parallel): Rename function to...
    (cp_parser_oacc_compute): ... this.  Handle PRAGMA_OACC_SERIAL.
    (cp_parser_omp_construct): Update accordingly.
    (cp_parser_pragma): Handle PRAGMA_OACC_SERIAL.  Fix alphabetic
    order.
    * pt.c (tsubst_expr): Handle OACC_SERIAL.

    gcc/fortran/
    * gfortran.h (gfc_statement): Add ST_OACC_SERIAL_LOOP,
    ST_OACC_END_SERIAL_LOOP, ST_OACC_SERIAL and ST_OACC_END_SERIAL
    enumeration constants.
    (gfc_exec_op): Add EXEC_OACC_SERIAL_LOOP and EXEC_OACC_SERIAL
    enumeration constants.
    * match.h (gfc_match_oacc_serial): New prototype.
    (gfc_match_oacc_serial_loop): Likewise.
    * dump-parse-tree.c (show_omp_node, show_code_node): Handle
    EXEC_OACC_SERIAL_LOOP and EXEC_OACC_SERIAL.
    * match.c (match_exit_cycle): Handle EXEC_OACC_SERIAL_LOOP.
    * openmp.c (OACC_SERIAL_CLAUSES): New macro.
    (gfc_match_oacc_serial_loop): New function.
    (gfc_match_oacc_serial): Likewise.
    (oacc_is_loop): Handle EXEC_OACC_SERIAL_LOOP.
    (resolve_omp_clauses): Handle EXEC_OACC_SERIAL.
    (oacc_code_to_statement): Handle EXEC_OACC_SERIAL and
    EXEC_OACC_SERIAL_LOOP.
    (gfc_resolve_oacc_directive): Likewise.
    * parse.c (decode_oacc_directive) <'s'>: Add case for "serial"
    and "serial loop".
    (next_statement): Handle ST_OACC_SERIAL_LOOP and ST_OACC_SERIAL.
    (gfc_ascii_statement): Likewise.  Handle ST_OACC_END_SERIAL_LOOP
    and ST_OACC_END_SERIAL.
    (parse_oacc_structured_block): Handle ST_OACC_SERIAL.
    (parse_oacc_loop): Handle ST_OACC_SERIAL_LOOP and
    ST_OACC_END_SERIAL_LOOP.
    (parse_executable): Handle ST_OACC_SERIAL_LOOP and
    ST_OACC_SERIAL.
    (is_oacc): Handle EXEC_OACC_SERIAL_LOOP and EXEC_OACC_SERIAL.
    * resolve.c (gfc_resolve_blocks, gfc_resolve_code): Likewise.
    * st.c (gfc_free_statement): Likewise.
    * trans-openmp.c (gfc_trans_oacc_construct): Handle
    EXEC_OACC_SERIAL.
    (gfc_trans_oacc_combined_directive): Handle
    EXEC_OACC_SERIAL_LOOP.
    (gfc_trans_oacc_directive): Handle EXEC_OACC_SERIAL_LOOP and
    EXEC_OACC_SERIAL.
    * trans.c (trans_code): Likewise.

    gcc/testsuite/
    * c-c++-common/goacc/parallel-dims.c: New test.
    * gfortran.dg/goacc/parallel-dims.f90: New test.

    libgomp/
    * testsuite/libgomp.oacc-c-c++-common/parallel-dims.c: New test.
    * testsuite/libgomp.oacc-fortran/parallel-dims-aux.c: New test.
    * testsuite/libgomp.oacc-fortran/parallel-dims.f89: New test.
    * testsuite/libgomp.oacc-fortran/parallel-dims-2.f90: New test.

Reviewed-by: Thomas Schwinge <thomas@codesourcery.com>


Co-Authored-By: Frederik Harwath <frederik@codesourcery.com>
Co-Authored-By: Thomas Schwinge <thomas@codesourcery.com>
Co-Authored-By: Tobias Burnus <tobias@codesourcery.com>

From-SVN: r278082

2 files changed, 39 insertions, 5 deletions

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index e3a5120..a7d86a2 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,13 @@
+2019-11-12  Maciej W. Rozycki  <macro@codesourcery.com>
+	    Frederik Harwath  <frederik@codesourcery.com>
+
+	gcc/c/
+	* c-parser.c (OACC_SERIAL_CLAUSE_MASK): New macro.
+	(c_parser_oacc_kernels_parallel): Rename function to...
+	(c_parser_oacc_compute): ... this.  Handle PRAGMA_OACC_SERIAL.
+	(c_parser_omp_construct): Update accordingly.
+
+
 2019-11-11  Jakub Jelinek  <jakub@redhat.com>
 
 	* c-parser.c (c_parser_translation_unit): Diagnose declare target
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 12deb3e..8d7ecf4 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -16280,6 +16280,11 @@ c_parser_oacc_loop (location_t loc, c_parser *parser, char *p_name,
    # pragma acc parallel oacc-parallel-clause[optseq] new-line
      structured-block
 
+   OpenACC 2.6:
+
+   # pragma acc serial oacc-serial-clause[optseq] new-line
+     structured-block
+
    LOC is the location of the #pragma token.
 */
 
@@ -16316,10 +16321,24 @@ c_parser_oacc_loop (location_t loc, c_parser *parser, char *p_name,
 	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_VECTOR_LENGTH)	\
 	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_WAIT) )
 
+#define OACC_SERIAL_CLAUSE_MASK					\
+	( (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_ASYNC)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_COPY)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_COPYIN)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_COPYOUT)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_CREATE)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_DEFAULT)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_DEVICEPTR)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_IF)			\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_PRIVATE)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_FIRSTPRIVATE)	\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_PRESENT)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_REDUCTION)		\
+	| (OMP_CLAUSE_MASK_1 << PRAGMA_OACC_CLAUSE_WAIT) )
+
 static tree
-c_parser_oacc_kernels_parallel (location_t loc, c_parser *parser,
-				enum pragma_kind p_kind, char *p_name,
-				bool *if_p)
+c_parser_oacc_compute (location_t loc, c_parser *parser,
+		       enum pragma_kind p_kind, char *p_name, bool *if_p)
 {
   omp_clause_mask mask;
   enum tree_code code;
@@ -16335,6 +16354,11 @@ c_parser_oacc_kernels_parallel (location_t loc, c_parser *parser,
       mask = OACC_PARALLEL_CLAUSE_MASK;
       code = OACC_PARALLEL;
       break;
+    case PRAGMA_OACC_SERIAL:
+      strcat (p_name, " serial");
+      mask = OACC_SERIAL_CLAUSE_MASK;
+      code = OACC_SERIAL;
+      break;
     default:
       gcc_unreachable ();
     }
@@ -20798,9 +20822,9 @@ c_parser_omp_construct (c_parser *parser, bool *if_p)
       break;
     case PRAGMA_OACC_KERNELS:
     case PRAGMA_OACC_PARALLEL:
+    case PRAGMA_OACC_SERIAL:
       strcpy (p_name, "#pragma acc");
-      stmt = c_parser_oacc_kernels_parallel (loc, parser, p_kind, p_name,
-					     if_p);
+      stmt = c_parser_oacc_compute (loc, parser, p_kind, p_name, if_p);
       break;
     case PRAGMA_OACC_LOOP:
       strcpy (p_name, "#pragma acc");