OpenMP: Support acquires/release in 'omp require atomic_default_mem_order'

This is an OpenMP 5.2 feature.

gcc/c/ChangeLog:

	* c-parser.cc (c_parser_omp_requires): Handle acquires/release
	in atomic_default_mem_order clause.
	(c_parser_omp_atomic): Update.

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_omp_requires): Handle acquires/release
	in atomic_default_mem_order clause.
	(cp_parser_omp_atomic): Update.

gcc/fortran/ChangeLog:

	* gfortran.h (enum gfc_omp_requires_kind): Add
	OMP_REQ_ATOMIC_MEM_ORDER_ACQUIRE and OMP_REQ_ATOMIC_MEM_ORDER_RELEASE.
	(gfc_namespace): Add a 7th bit to omp_requires.
	* module.cc (enum ab_attribute): Add AB_OMP_REQ_MEM_ORDER_ACQUIRE
	and AB_OMP_REQ_MEM_ORDER_RELEASE
	(mio_symbol_attribute): Handle it.
	* openmp.cc (gfc_omp_requires_add_clause): Update for acquire/release.
	(gfc_match_omp_requires): Likewise.
	(gfc_match_omp_atomic): Handle them for atomic_default_mem_order.
	* parse.cc: Likewise.

gcc/testsuite/ChangeLog:

	* c-c++-common/gomp/requires-3.c: Update for now valid code.
	* gfortran.dg/gomp/requires-3.f90: Likewise.
	* gfortran.dg/gomp/requires-2.f90: Update dg-error.
	* gfortran.dg/gomp/requires-5.f90: Likewise.
	* c-c++-common/gomp/requires-5.c: New test.
	* c-c++-common/gomp/requires-6.c: New test.
	* c-c++-common/gomp/requires-7.c: New test.
	* c-c++-common/gomp/requires-8.c: New test.
	* gfortran.dg/gomp/requires-10.f90: New test.
	* gfortran.dg/gomp/requires-11.f90: New test.

5 files changed, 75 insertions, 4 deletions

diff --git a/gcc/testsuite/c-c++-common/gomp/requires-3.c b/gcc/testsuite/c-c++-common/gomp/requires-3.c
index bd2479b..2fd601a 100644
--- a/gcc/testsuite/c-c++-common/gomp/requires-3.c
+++ b/gcc/testsuite/c-c++-common/gomp/requires-3.c
@@ -1,6 +1,6 @@
-#pragma omp requires atomic_default_mem_order(acquire)	/* { dg-error "expected 'seq_cst', 'relaxed' or 'acq_rel'" } */
-#pragma omp requires atomic_default_mem_order(release)	/* { dg-error "expected 'seq_cst', 'relaxed' or 'acq_rel'" } */
-#pragma omp requires atomic_default_mem_order(foobar)	/* { dg-error "expected 'seq_cst', 'relaxed' or 'acq_rel'" } */
-#pragma omp requires atomic_default_mem_order (	/* { dg-error "expected 'seq_cst', 'relaxed' or 'acq_rel'" } */
+#pragma omp requires atomic_default_mem_order(foobar)	/* { dg-error "expected 'acq_rel', 'acquire', 'relaxed', 'release' or 'seq_cst'" } */
+#pragma omp requires atomic_default_mem_order (	/* { dg-error "expected 'acq_rel', 'acquire', 'relaxed', 'release' or 'seq_cst'" } */
 /* { dg-error "expected '\\\)' before end of line" "" { target *-*-* } .-1 } */
 #pragma omp requires atomic_default_mem_order(seq_cst),	/* { dg-error "expected end of line before ',' token" } */
+/* Valid since since 5.2, but ... */
+#pragma omp requires atomic_default_mem_order(acquire)	/* { dg-error "more than one 'atomic_default_mem_order' clause in a single compilation unit" } */
diff --git a/gcc/testsuite/c-c++-common/gomp/requires-5.c b/gcc/testsuite/c-c++-common/gomp/requires-5.c
new file mode 100644
index 0000000..53e0b75
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/requires-5.c
@@ -0,0 +1,23 @@
+/* { dg-additional-options "-fdump-tree-original" }  */
+
+#pragma omp requires atomic_default_mem_order(release)
+
+int
+foo (int x, int y)
+{
+  int z;
+
+  #pragma omp atomic write
+    x = y;
+
+  #pragma omp atomic update
+    x += 1;
+
+  #pragma omp atomic read acquire
+    z = x;
+  return z;
+}
+
+/* { dg-final { scan-tree-dump "#pragma omp atomic release" "original" } } */
+/* { dg-final { scan-tree-dump "#pragma omp atomic release" "original" } } */
+/* { dg-final { scan-tree-dump "z = #pragma omp atomic read acquire" "original" } } */
diff --git a/gcc/testsuite/c-c++-common/gomp/requires-6.c b/gcc/testsuite/c-c++-common/gomp/requires-6.c
new file mode 100644
index 0000000..4470c8cae
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/requires-6.c
@@ -0,0 +1,23 @@
+/* { dg-additional-options "-fdump-tree-original" }  */
+
+#pragma omp requires atomic_default_mem_order(acquire)
+
+int
+bar (int a, int b)
+{
+  int c;
+
+  #pragma omp atomic write release
+    a = b;
+
+  #pragma omp atomic update
+    a += 1;
+
+  #pragma omp atomic read
+    c = a;
+  return c;
+}
+
+/* { dg-final { scan-tree-dump "#pragma omp atomic release" "original" } } */
+/* { dg-final { scan-tree-dump "#pragma omp atomic acquire" "original" } } */
+/* { dg-final { scan-tree-dump "c = #pragma omp atomic read acquire" "original" } } */
diff --git a/gcc/testsuite/c-c++-common/gomp/requires-7.c b/gcc/testsuite/c-c++-common/gomp/requires-7.c
new file mode 100644
index 0000000..4735ef2
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/requires-7.c
@@ -0,0 +1,11 @@
+#pragma omp requires atomic_default_mem_order(release)
+
+int
+foo (int x)
+{
+  int z;
+
+  #pragma omp atomic read /* { dg-error "'#pragma omp atomic read' incompatible with 'release' clause implicitly provided by a 'requires' directive" } */
+    z = x;
+  return z;
+}
diff --git a/gcc/testsuite/c-c++-common/gomp/requires-8.c b/gcc/testsuite/c-c++-common/gomp/requires-8.c
new file mode 100644
index 0000000..4d56e7d
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/requires-8.c
@@ -0,0 +1,14 @@
+#pragma omp requires atomic_default_mem_order(acquire)
+
+int
+bar (int a, int b)
+{
+  int c;
+
+  #pragma omp atomic write /* { dg-error "'#pragma omp atomic write' incompatible with 'acquire' clause implicitly provided by a 'requires' directive" } */
+    a = b;
+
+  #pragma omp atomic read
+    c = a;
+  return c;
+}