[gcc r17-2560] openmp: Add OMPT variants of GOMP_scope_start

https://gcc.gnu.org/g:f657c8992ffc1695a8cc4ade5713fdf8ae5b8dfc

commit r17-2560-gf657c8992ffc1695a8cc4ade5713fdf8ae5b8dfc
Author: Paul-Antoine Arras <[email protected]>
Date:   Mon Jul 20 11:48:59 2026 +0200

    openmp: Add OMPT variants of GOMP_scope_start
    
    GOMP_scope_start is emitted only for task reductions without -fopenmp-ompt
    (unchanged). With -fopenmp-ompt, both GOMP_scope_start_with_end and
    GOMP_scope_end are emitted, whether a task reduction is specified or not.
    
    gcc/ChangeLog:
    
            * omp-builtins.def (BUILT_IN_GOMP_SCOPE_START_WITH_END): New
            builtin.
            (BUILT_IN_GOMP_SCOPE_END): Likewise.
            * omp-low.cc (lower_omp_scope): Emit calls to
            GOMP_scope_start_with_end and GOMP_scope_end when -fopenmp-ompt.
    
    libgomp/ChangeLog:
    
            * libgomp.map: Add GOMP_scope_start_with_end and GOMP_scope_end.
            * libgomp_g.h (GOMP_scope_start_with_end): Declare.
            (GOMP_scope_end): Likewise.
            * scope.c (GOMP_scope_start_with_end): New function.
            (GOMP_scope_end): New stub.
    
    gcc/testsuite/ChangeLog:
    
            * c-c++-common/gomp/scope-7.c: New test.
            * c-c++-common/gomp/scope-8.c: New test.

Diff:
---
 gcc/omp-builtins.def                      |  4 ++++
 gcc/omp-low.cc                            | 17 +++++++++++++++-
 gcc/testsuite/c-c++-common/gomp/scope-7.c | 26 +++++++++++++++++++++++++
 gcc/testsuite/c-c++-common/gomp/scope-8.c | 25 ++++++++++++++++++++++++
 libgomp/libgomp.map                       |  2 ++
 libgomp/libgomp_g.h                       |  2 ++
 libgomp/scope.c                           | 32 +++++++++++++++++++++++++++++++
 7 files changed, 107 insertions(+), 1 deletion(-)

diff --git a/gcc/omp-builtins.def b/gcc/omp-builtins.def
index 29b3b72c2cdf..6b5e231eb0a8 100644
--- a/gcc/omp-builtins.def
+++ b/gcc/omp-builtins.def
@@ -456,6 +456,10 @@ DEF_GOMP_BUILTIN (BUILT_IN_GOMP_SINGLE_COPY_END, "GOMP_single_copy_end",
 		  BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
 DEF_GOMP_BUILTIN (BUILT_IN_GOMP_SCOPE_START, "GOMP_scope_start",
 		  BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_GOMP_BUILTIN (BUILT_IN_GOMP_SCOPE_START_WITH_END, "GOMP_scope_start_with_end",
+		  BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_GOMP_BUILTIN (BUILT_IN_GOMP_SCOPE_END, "GOMP_scope_end",
+		  BT_FN_VOID, ATTR_NOTHROW_LEAF_LIST)
 DEF_GOMP_BUILTIN (BUILT_IN_GOMP_OFFLOAD_REGISTER, "GOMP_offload_register_ver",
 		  BT_FN_VOID_UINT_PTR_INT_PTR, ATTR_NOTHROW_LIST)
 DEF_GOMP_BUILTIN (BUILT_IN_GOMP_OFFLOAD_UNREGISTER,
diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc
index d87b6b6b2924..19ec304dc811 100644
--- a/gcc/omp-low.cc
+++ b/gcc/omp-low.cc
@@ -9035,10 +9035,18 @@ lower_omp_scope (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 				 gimple_omp_scope_clauses (scope_stmt),
 				 &bind_body, &tred_dlist);
       rclauses = c;
-      tree fndecl = builtin_decl_explicit (BUILT_IN_GOMP_SCOPE_START);
+      tree fndecl = builtin_decl_explicit (
+	flag_openmp_ompt ? BUILT_IN_GOMP_SCOPE_START_WITH_END
+			 : BUILT_IN_GOMP_SCOPE_START);
       gimple *stmt = gimple_build_call (fndecl, 1, temp);
       gimple_seq_add_stmt (&bind_body, stmt);
     }
+  else if (flag_openmp_ompt)
+    {
+      tree fndecl = builtin_decl_explicit (BUILT_IN_GOMP_SCOPE_START_WITH_END);
+      gimple *stmt = gimple_build_call (fndecl, 1, null_pointer_node);
+      gimple_seq_add_stmt (&bind_body, stmt);
+    }
 
   lower_rec_input_clauses (gimple_omp_scope_clauses (scope_stmt),
 			   &bind_body, &dlist, ctx, NULL);
@@ -9068,6 +9076,13 @@ lower_omp_scope (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 
   bind_body = maybe_catch_exception (bind_body);
 
+  if (flag_openmp_ompt)
+    {
+      tree fndecl = builtin_decl_explicit (BUILT_IN_GOMP_SCOPE_END);
+      gcall *g = gimple_build_call (fndecl, 0);
+      gimple_seq_add_stmt (&bind_body_tail, g);
+    }
+
   bool nowait = omp_find_clause (gimple_omp_scope_clauses (scope_stmt),
 				 OMP_CLAUSE_NOWAIT) != NULL_TREE;
   gimple *g = gimple_build_omp_return (nowait);
diff --git a/gcc/testsuite/c-c++-common/gomp/scope-7.c b/gcc/testsuite/c-c++-common/gomp/scope-7.c
new file mode 100644
index 000000000000..9db2fd1053cb
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/scope-7.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-fopenmp-ompt -fdump-tree-omplower" } */
+
+/* Check that OMPT variants of libgomp calls are emitted for the scope
+   construct, both with and without a task reduction clause.  */
+
+int x;
+
+void
+f1 (void)
+{
+  #pragma omp scope
+  ;
+}
+
+void
+f2 (void)
+{
+#pragma omp scope reduction(task, + : x)
+  ;
+}
+
+/* { dg-final { scan-tree-dump-times "GOMP_scope_start_with_end \\(0B\\)" 1 "omplower" } } */
+/* { dg-final { scan-tree-dump-times "GOMP_scope_start_with_end \\(D\.\[0-9\]+\\)" 1 "omplower" } } */
+/* { dg-final { scan-tree-dump-times "GOMP_scope_end" 2 "omplower" } } */
+/* { dg-final { scan-tree-dump-not "GOMP_scope_start \\(" "omplower" } } */
diff --git a/gcc/testsuite/c-c++-common/gomp/scope-8.c b/gcc/testsuite/c-c++-common/gomp/scope-8.c
new file mode 100644
index 000000000000..2a36b1aa8805
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/scope-8.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-fdump-tree-omplower" } */
+
+/* Check that a single, non-OMPT variant of libgomp call is emitted for the
+   scope construct, only with a task reduction clause.  */
+
+int x;
+
+void
+f1 (void)
+{
+  #pragma omp scope
+  ;
+}
+
+void
+f2 (void)
+{
+  #pragma omp scope reduction(task, +:x)
+  ;
+}
+
+/* { dg-final { scan-tree-dump-times "GOMP_scope_start \\(" 1 "omplower" } } */
+/* { dg-final { scan-tree-dump-not "GOMP_scope_start_with_end" "omplower" } } */
+/* { dg-final { scan-tree-dump-not "GOMP_scope_end" "omplower" } } */
diff --git a/libgomp/libgomp.map b/libgomp/libgomp.map
index 81bad4d23296..8a59d4965b39 100644
--- a/libgomp/libgomp.map
+++ b/libgomp/libgomp.map
@@ -501,6 +501,8 @@ GOMP_6.0.2 {
 	GOMP_reduction_end;
 	GOMP_single_start_with_end;
 	GOMP_single_end;
+	GOMP_scope_start_with_end;
+	GOMP_scope_end;
 } GOMP_6.0.1;
 
 OACC_2.0 {
diff --git a/libgomp/libgomp_g.h b/libgomp/libgomp_g.h
index be3e349a4170..bc0589672d43 100644
--- a/libgomp/libgomp_g.h
+++ b/libgomp/libgomp_g.h
@@ -357,6 +357,8 @@ extern void GOMP_single_copy_end (void *);
 /* scope.c */
 
 extern void GOMP_scope_start (uintptr_t *);
+extern void GOMP_scope_start_with_end (uintptr_t *);
+extern void GOMP_scope_end (void);
 
 /* target.c */
 
diff --git a/libgomp/scope.c b/libgomp/scope.c
index df52e472e147..00a8701d9f1d 100644
--- a/libgomp/scope.c
+++ b/libgomp/scope.c
@@ -60,3 +60,35 @@ GOMP_scope_start (uintptr_t *reductions)
 					      first_reductions);
     }
 }
+
+/* OMPT variant enabled by -fopenmp-ompt. Called at the beginning of every scope
+   construct even without reduction.  */
+
+void
+GOMP_scope_start_with_end (uintptr_t *reductions)
+{
+  if (!reductions)
+    return;
+
+  struct gomp_thread *thr = gomp_thread ();
+
+  gomp_workshare_taskgroup_start ();
+  if (gomp_work_share_start (0))
+    {
+      GOMP_taskgroup_reduction_register (reductions);
+      thr->task->taskgroup->workshare = true;
+      thr->ts.work_share->task_reductions = reductions;
+      gomp_work_share_init_done ();
+    }
+  else
+    {
+      uintptr_t *first_reductions = thr->ts.work_share->task_reductions;
+      gomp_workshare_task_reduction_register (reductions, first_reductions);
+    }
+}
+
+/* Stub for OMPT callback enabled by -fopenmp-ompt.  */
+
+void
+GOMP_scope_end (void)
+{}