[gcc/devel/omp/gcc-11] Allow gang reductions inside serial constructs

[gcc/devel/omp/gcc-11] Allow gang reductions inside serial constructs

[Kwok Yeung]

https://gcc.gnu.org/g:cd75dfe029ca229d30fa9242f44d9ca85f415209

commit cd75dfe029ca229d30fa9242f44d9ca85f415209
Author: Kwok Cheung Yeung <kcy@codesourcery.com>
Date:   Fri Mar 13 11:13:49 2020 -0700

    Allow gang reductions inside serial constructs
    
    2020-03-13  Kwok Cheung Yeung  <kcy@codesourcery.com>
    
            gcc/fortran/
            * openmp.c (oacc_is_serial, oacc_is_parallel_or_serial): New.
            (resolve_oacc_loop_blocks): Use oacc_is_parallel_or_serial instead of
            oacc_is_parallel.

Diff:
---
 gcc/fortran/ChangeLog.omp |  6 ++++++
 gcc/fortran/openmp.c      | 14 +++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/gcc/fortran/ChangeLog.omp b/gcc/fortran/ChangeLog.omp
index 4a64c0955a9..ee4f76d28de 100644
--- a/gcc/fortran/ChangeLog.omp
+++ b/gcc/fortran/ChangeLog.omp
@@ -1,3 +1,9 @@
+2020-03-13  Kwok Cheung Yeung  <kcy@codesourcery.com>
+
+	* openmp.c (oacc_is_serial, oacc_is_parallel_or_serial): New.
+	(resolve_oacc_loop_blocks): Use oacc_is_parallel_or_serial instead of
+	oacc_is_parallel.
+
 2020-02-19  Julian Brown  <julian@codesourcery.com>
 
 	* trans-openmp.c (gfc_omp_check_optional_argument): Handle non-decl
diff --git a/gcc/fortran/openmp.c b/gcc/fortran/openmp.c
index b7e446d64d7..e3a8df7cfe2 100644
--- a/gcc/fortran/openmp.c
+++ b/gcc/fortran/openmp.c
@@ -6692,6 +6692,18 @@ oacc_is_parallel (gfc_code *code)
   return code->op == EXEC_OACC_PARALLEL || code->op == EXEC_OACC_PARALLEL_LOOP;
 }
 
+static bool
+oacc_is_serial (gfc_code *code)
+{
+  return code->op == EXEC_OACC_SERIAL || code->op == EXEC_OACC_SERIAL_LOOP;
+}
+
+static bool
+oacc_is_parallel_or_serial (gfc_code *code)
+{
+  return oacc_is_parallel (code) || oacc_is_serial (code);
+}
+
 static gfc_statement
 omp_code_to_statement (gfc_code *code)
 {
@@ -6965,7 +6977,7 @@ resolve_oacc_loop_blocks (gfc_code *code)
       for (c = omp_current_ctx; c; c = c->previous)
 	if (!oacc_is_loop (c->code))
 	  break;
-      if (c == NULL || !oacc_is_parallel (c->code))
+      if (c == NULL || !oacc_is_parallel_or_serial (c->code))
 	gfc_error ("gang reduction on an orphan loop at %L", &code->loc);
     }