Fortran: Add OpenMP's assume(s) directives

libgomp/ChangeLog:

	* libgomp.texi (OpenMP 5.1 Impl. Status): Mark 'assume' as 'Y'.

gcc/fortran/ChangeLog:

	* dump-parse-tree.cc (show_omp_assumes): New.
	(show_omp_clauses, show_namespace): Call it.
	(show_omp_node, show_code_node): Handle OpenMP ASSUME.
	* gfortran.h (enum gfc_statement): Add ST_OMP_ASSUME,
	ST_OMP_END_ASSUME, ST_OMP_ASSUMES and ST_NOTHING.
	(gfc_exec_op): Add EXEC_OMP_ASSUME.
	(gfc_omp_assumptions): New struct.
	(gfc_get_omp_assumptions): New XCNEW #define.
	(gfc_omp_clauses, gfc_namespace): Add assume member.
	(gfc_resolve_omp_assumptions): New prototype.
	* match.h (gfc_match_omp_assume, gfc_match_omp_assumes): New.
	* openmp.cc (omp_code_to_statement): Forward declare.
	(enum gfc_omp_directive_kind, struct gfc_omp_directive): New.
	(gfc_free_omp_clauses): Free assume member and its struct data.
	(enum omp_mask2): Add OMP_CLAUSE_ASSUMPTIONS.
	(gfc_omp_absent_contains_clause): New.
	(gfc_match_omp_clauses): Call it; optionally use passed
	omp_clauses argument.
	(omp_verify_merge_absent_contains, gfc_match_omp_assume,
	 gfc_match_omp_assumes, gfc_resolve_omp_assumptions): New.
	(resolve_omp_clauses): Call the latter.
	(gfc_resolve_omp_directive, omp_code_to_statement): Handle
	EXEC_OMP_ASSUME.
	* parse.cc (decode_omp_directive): Parse OpenMP ASSUME(S).
	(next_statement, parse_executable, parse_omp_structured_block):
	Handle ST_OMP_ASSUME.
	(case_omp_decl): Add ST_OMP_ASSUMES.
	(gfc_ascii_statement): Handle Assumes, optional return
	string without '!$OMP '/'!$ACC ' prefix.
	* parse.h (gfc_ascii_statement): Add optional bool arg to prototype.
	* resolve.cc (gfc_resolve_blocks, gfc_resolve_code): Add
	EXEC_OMP_ASSUME.
	(gfc_resolve): Resolve ASSUMES directive.
	* symbol.cc (gfc_free_namespace): Free omp_assumes member.
	* st.cc (gfc_free_statement): Handle EXEC_OMP_ASSUME.
	* trans-openmp.cc (gfc_trans_omp_directive): Likewise.
	* trans.cc (trans_code): Likewise.

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/assume-1.f90: New test.
	* gfortran.dg/gomp/assume-2.f90: New test.
	* gfortran.dg/gomp/assumes-1.f90: New test.
	* gfortran.dg/gomp/assumes-2.f90: New test.

1 files changed, 28 insertions, 3 deletions

diff --git a/gcc/fortran/parse.cc b/gcc/fortran/parse.cc
index 2e2e977..f04fd13 100644
--- a/gcc/fortran/parse.cc
+++ b/gcc/fortran/parse.cc
@@ -885,6 +885,8 @@ decode_omp_directive (void)
   switch (c)
     {
     case 'a':
+      matcho ("assumes", gfc_match_omp_assumes, ST_OMP_ASSUMES);
+      matchs ("assume", gfc_match_omp_assume, ST_OMP_ASSUME);
       matcho ("atomic", gfc_match_omp_atomic, ST_OMP_ATOMIC);
       break;
     case 'b':
@@ -913,6 +915,7 @@ decode_omp_directive (void)
       break;
     case 'e':
       matcho ("error", gfc_match_omp_error, ST_OMP_ERROR);
+      matchs ("end assume", gfc_match_omp_eos_error, ST_OMP_END_ASSUME);
       matcho ("end atomic", gfc_match_omp_eos_error, ST_OMP_END_ATOMIC);
       matcho ("end critical", gfc_match_omp_end_critical, ST_OMP_END_CRITICAL);
       matchs ("end distribute parallel do simd", gfc_match_omp_eos_error,
@@ -1716,6 +1719,7 @@ next_statement (void)
   case ST_OMP_TARGET_SIMD: case ST_OMP_TASKLOOP: case ST_OMP_TASKLOOP_SIMD: \
   case ST_OMP_LOOP: case ST_OMP_PARALLEL_LOOP: case ST_OMP_TEAMS_LOOP: \
   case ST_OMP_TARGET_PARALLEL_LOOP: case ST_OMP_TARGET_TEAMS_LOOP: \
+  case ST_OMP_ASSUME: \
   case ST_CRITICAL: \
   case ST_OACC_PARALLEL_LOOP: case ST_OACC_PARALLEL: case ST_OACC_KERNELS: \
   case ST_OACC_DATA: case ST_OACC_HOST_DATA: case ST_OACC_LOOP: \
@@ -1733,7 +1737,7 @@ next_statement (void)
 
 #define case_omp_decl case ST_OMP_THREADPRIVATE: case ST_OMP_DECLARE_SIMD: \
   case ST_OMP_DECLARE_TARGET: case ST_OMP_DECLARE_REDUCTION: \
-  case ST_OMP_DECLARE_VARIANT: \
+  case ST_OMP_DECLARE_VARIANT: case ST_OMP_ASSUMES: \
   case ST_OMP_REQUIRES: case ST_OACC_ROUTINE: case ST_OACC_DECLARE
 
 /* Block end statements.  Errors associated with interchanging these
@@ -1925,10 +1929,11 @@ gfc_enclosing_unit (gfc_compile_state * result)
 }
 
 
-/* Translate a statement enum to a string.  */
+/* Translate a statement enum to a string.  If strip_sentinel is true,
+   the !$OMP/!$ACC sentinel is excluded.  */
 
 const char *
-gfc_ascii_statement (gfc_statement st)
+gfc_ascii_statement (gfc_statement st, bool strip_sentinel)
 {
   const char *p;
 
@@ -2353,6 +2358,12 @@ gfc_ascii_statement (gfc_statement st)
     case ST_OACC_END_ATOMIC:
       p = "!$ACC END ATOMIC";
       break;
+    case ST_OMP_ASSUME:
+      p = "!$OMP ASSUME";
+      break;
+    case ST_OMP_ASSUMES:
+      p = "!$OMP ASSUMES";
+      break;
     case ST_OMP_ATOMIC:
       p = "!$OMP ATOMIC";
       break;
@@ -2401,6 +2412,9 @@ gfc_ascii_statement (gfc_statement st)
     case ST_OMP_DO_SIMD:
       p = "!$OMP DO SIMD";
       break;
+    case ST_OMP_END_ASSUME:
+      p = "!$OMP END ASSUME";
+      break;
     case ST_OMP_END_ATOMIC:
       p = "!$OMP END ATOMIC";
       break;
@@ -2600,6 +2614,10 @@ gfc_ascii_statement (gfc_statement st)
     case ST_OMP_ORDERED_DEPEND:
       p = "!$OMP ORDERED";
       break;
+    case ST_OMP_NOTHING:
+      /* Note: gfc_match_omp_nothing returns ST_NONE. */
+      p = "!$OMP NOTHING";
+      break;
     case ST_OMP_PARALLEL:
       p = "!$OMP PARALLEL";
       break;
@@ -2751,6 +2769,8 @@ gfc_ascii_statement (gfc_statement st)
       gfc_internal_error ("gfc_ascii_statement(): Bad statement code");
     }
 
+  if (strip_sentinel && p[0] == '!')
+    return p + strlen ("!$OMP ");
   return p;
 }
 
@@ -5518,6 +5538,9 @@ parse_omp_structured_block (gfc_statement omp_st, bool workshare_stmts_only)
 
   switch (omp_st)
     {
+    case ST_OMP_ASSUME:
+      omp_end_st = ST_OMP_END_ASSUME;
+      break;
     case ST_OMP_PARALLEL:
       omp_end_st = ST_OMP_END_PARALLEL;
       break;
@@ -5651,6 +5674,7 @@ parse_omp_structured_block (gfc_statement omp_st, bool workshare_stmts_only)
 		  parse_forall_block ();
 		  break;
 
+		case ST_OMP_ASSUME:
 		case ST_OMP_PARALLEL:
 		case ST_OMP_PARALLEL_MASKED:
 		case ST_OMP_PARALLEL_MASTER:
@@ -5874,6 +5898,7 @@ parse_executable (gfc_statement st)
 	  parse_oacc_structured_block (st);
 	  break;
 
+	case ST_OMP_ASSUME:
 	case ST_OMP_PARALLEL:
 	case ST_OMP_PARALLEL_MASKED:
 	case ST_OMP_PARALLEL_MASTER: