[gcc/devel/omp/gcc-12] Fix lexically-nested data mappings for no_alloc or optional arguments

[gcc/devel/omp/gcc-12] Fix lexically-nested data mappings for no_alloc or optional arguments

[Kwok Yeung]

https://gcc.gnu.org/g:43a2dffa47aefeba76866027a68bc7308df0a167

commit 43a2dffa47aefeba76866027a68bc7308df0a167
Author: Julian Brown <julian@codesourcery.com>
Date:   Mon May 20 17:27:38 2019 -0700

    Fix lexically-nested data mappings for no_alloc or optional arguments
    
            gcc/
            * gimplify.cc (gimplify_adjust_omp_clauses_1): Support implied no_alloc
            and optional arguments based on mappings in enclosing data regions.

Diff:
---
 gcc/ChangeLog.omp |  5 +++++
 gcc/gimplify.cc   | 12 ++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp
index 286ff0fda02..40d7e5ad8a5 100644
--- a/gcc/ChangeLog.omp
+++ b/gcc/ChangeLog.omp
@@ -1,3 +1,8 @@
+2019-05-20  Julian Brown  <julian@codesourcery.com>
+
+	* gimplify.cc (gimplify_adjust_omp_clauses_1): Support implied no_alloc
+	and optional arguments based on mappings in enclosing data regions.
+
 2019-05-19  Julian Brown  <julian@codesourcery.com>
 
 	* gimplify.cc (oacc_array_mapping_info): Add REF field.
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index 355b5b0bf56..477576ff0e7 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -11336,9 +11336,12 @@ gimplify_adjust_omp_clauses_1 (splay_tree_node n, void *data)
     {
       tree mapping = array_info->mapping;
       tree pointer = array_info->pointer;
-      const gomp_map_kind presence_kind
-	= omp_check_optional_argument (decl, false) ? GOMP_MAP_IF_PRESENT
-						    : GOMP_MAP_FORCE_PRESENT;
+      gomp_map_kind presence_kind = GOMP_MAP_FORCE_PRESENT;
+      bool no_alloc = (OMP_CLAUSE_CODE (mapping) == OMP_CLAUSE_MAP
+		       && OMP_CLAUSE_MAP_KIND (mapping) == GOMP_MAP_IF_PRESENT);
+
+      if (no_alloc || omp_check_optional_argument (decl, false))
+        presence_kind = GOMP_MAP_IF_PRESENT;
 
       if (code == OMP_CLAUSE_FIRSTPRIVATE)
 	/* Oops, we have the wrong type of clause.  Rebuild it.  */
@@ -11353,7 +11356,8 @@ gimplify_adjust_omp_clauses_1 (splay_tree_node n, void *data)
       tree nc = build_omp_clause (OMP_CLAUSE_LOCATION (clause),
 				  OMP_CLAUSE_MAP);
       OMP_CLAUSE_DECL (nc) = unshare_expr (OMP_CLAUSE_DECL (pointer));
-      OMP_CLAUSE_SET_MAP_KIND (nc, GOMP_MAP_POINTER);
+      OMP_CLAUSE_SET_MAP_KIND (nc, no_alloc ? GOMP_MAP_FIRSTPRIVATE_POINTER
+					    : GOMP_MAP_POINTER);
 
       /* For GOMP_MAP_FIRSTPRIVATE_POINTER, this is a bias, not a size.  */
       OMP_CLAUSE_SIZE (nc) = unshare_expr (OMP_CLAUSE_SIZE (pointer));