[PATCH 1/2] [OpenACC] Kernels loops annotation: C and C++.

Sandra Loosemore sandra@codesourcery.com
Wed Sep 9 17:53:54 GMT 2020


This patch detects loops in kernels regions that are candidates for
parallelization, and adds "#pragma acc loop auto" annotations to them.
This annotation is controlled by the -fopenacc-kernels-annotate-loops
option, which is enabled by default.  -Wopenacc-kernels-annotate-loops
can be used to produce diagnostics about loops that cannot be
annotated.

2020-09-08  Sandra Loosemore  <sandra@codesourcery.com>

	gcc/c-family/
	* c-common.h (c_oacc_annotate_loops_in_kernels_regions): Declare.
	* c-omp.c: Include tree-iterator.h.
	(enum annotation_state): New.
	(struct annotation_info): New.
	(do_not_annotate_loop): New.
	(do_not_annotate_loop_nest): New.
	(annotation_error): New.
	(c_finish_omp_for_internal): New.
	(c_finish_omp_for): Use c_finish_omp_for_internal.
	(is_local_var): New.
	(end_test_ok_for_annotation_r): New.
	(end_test_ok_for_annotation): New.
	(lang_specific_unwrap_initializer): New.
	(annotate_for_loop): New.
	(annotate_and_check_for_loop): New.
	(annotate_loops_in_kernels_regions): New.
	(c_oacc_annotate_loops_in_kernels_regions): New.
	* c.opt (Wopenacc-kernels-annotate-loops): New.
	(fopenacc-kernels-annotate-loops): New.

	gcc/c/
	* c-decl.c (c_unwrap_for_init): New.
	(finish_function): Call c_oacc_annotate_loops_in_kernels_regions.
	* c-parser.c (c_parser_oacc_loop): Set OACC_LOOP_COMBINED.

	gcc/cp/
	* decl.c (cp_unwrap_for_init): New.
	(finish_function): Call c_oacc_annotate_loops_in_kernels_regions.
	* parser.c (cp_parser_oacc_loop): Set OACC_LOOP_COMBINED.
	* semantics.c (handle_omp_array_sections_1): Call STRIP_NOPS
	on length and bound.
	(handle_omp_array_sections): Likewise.

	gcc/
	* doc/invoke.texi (Option Summary): Add entries for
	-Wopenacc-kernels-annotate-loops and
	-fno-openacc-kernels-annotate-loops.
	(Warning Options): Document -Wopenacc-kernels-annotate-loops.
	(Optimization Options): Document
	-fno-openacc-kernels-annotate-loops.
	* tree.h (OACC_LOOP_COMBINED): New.

	gcc/testsuite/
	* c-c++-common/goacc/classify-kernels-unparallelized.c: Add
	-fno-openacc-kernels-annotate-loops option.
	* c-c++-common/goacc/classify-kernels.c: Likewise.
	* c-c++-common/goacc/combined-directives.c: Likewise.
	* c-c++-common/goacc/kernels-counter-var-redundant-load.c:
	Likewise.
	* c-c++-common/goacc/kernels-counter-vars-function-scope.c:
	Likewise.
	* c-c++-common/goacc/kernels-double-reduction-n.c: Likewise.
	* c-c++-common/goacc/kernels-double-reduction.c: Likewise.
	* c-c++-common/goacc/kernels-loop-2.c: Likewise.
	* c-c++-common/goacc/kernels-loop-3.c: Likewise.
	* c-c++-common/goacc/kernels-loop-data-2.c: Likewise.
	* c-c++-common/goacc/kernels-loop-data-enter-exit-2.c: Likewise.
	* c-c++-common/goacc/kernels-loop-data-enter-exit.c: Likewise.
	* c-c++-common/goacc/kernels-loop-data-update.c: Likewise.
	* c-c++-common/goacc/kernels-loop-data.c: Likewise.
	* c-c++-common/goacc/kernels-loop-g.c: Likewise.
	* c-c++-common/goacc/kernels-loop-mod-not-zero.c: Likewise.
	* c-c++-common/goacc/kernels-loop-n.c: Likewise.
	* c-c++-common/goacc/kernels-loop-nest.c: Likewise.
	* c-c++-common/goacc/kernels-loop.c: Likewise.
	* c-c++-common/goacc/kernels-one-counter-var.c: Likewise.
	* c-c++-common/goacc/kernels-parallel-loop-data-enter-exit.c:
	Likewise.
	* c-c++-common/goacc/kernels-reduction.c: Likewise.
	* c-c++-common/goacc/kernels-loop-annotation-1.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-2.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-3.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-4.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-5.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-6.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-7.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-8.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-9.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-10.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-11.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-12.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-13.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-14.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-15.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-16.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-17.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-18.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-19.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-20.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-21.c: New.
	* c-c++-common/goacc/kernels-loop-annotation-22.c: New.
---
 gcc/c-family/c-common.h                            |   1 +
 gcc/c-family/c-omp.c                               | 916 +++++++++++++++++++--
 gcc/c-family/c.opt                                 |   8 +
 gcc/c/c-decl.c                                     |  28 +
 gcc/c/c-parser.c                                   |   3 +
 gcc/cp/decl.c                                      |  44 +
 gcc/cp/parser.c                                    |   3 +
 gcc/cp/semantics.c                                 |   9 +
 gcc/doc/invoke.texi                                |  34 +-
 .../goacc/classify-kernels-unparallelized.c        |   1 +
 .../c-c++-common/goacc/classify-kernels.c          |   1 +
 .../c-c++-common/goacc/combined-directives.c       |   2 +-
 .../goacc/kernels-counter-var-redundant-load.c     |   1 +
 .../goacc/kernels-counter-vars-function-scope.c    |   1 +
 .../goacc/kernels-double-reduction-n.c             |   1 +
 .../c-c++-common/goacc/kernels-double-reduction.c  |   1 +
 gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c  |   1 +
 gcc/testsuite/c-c++-common/goacc/kernels-loop-3.c  |   1 +
 .../c-c++-common/goacc/kernels-loop-annotation-1.c |  26 +
 .../goacc/kernels-loop-annotation-10.c             |  32 +
 .../goacc/kernels-loop-annotation-11.c             |  27 +
 .../goacc/kernels-loop-annotation-12.c             |  28 +
 .../goacc/kernels-loop-annotation-13.c             |  27 +
 .../goacc/kernels-loop-annotation-14.c             |  22 +
 .../goacc/kernels-loop-annotation-15.c             |  22 +
 .../goacc/kernels-loop-annotation-16.c             |  26 +
 .../goacc/kernels-loop-annotation-17.c             |  26 +
 .../goacc/kernels-loop-annotation-18.c             |  18 +
 .../goacc/kernels-loop-annotation-19.c             |  19 +
 .../c-c++-common/goacc/kernels-loop-annotation-2.c |  21 +
 .../goacc/kernels-loop-annotation-20.c             |  23 +
 .../goacc/kernels-loop-annotation-21.c             |  42 +
 .../goacc/kernels-loop-annotation-22.c             |  41 +
 .../c-c++-common/goacc/kernels-loop-annotation-3.c |  24 +
 .../c-c++-common/goacc/kernels-loop-annotation-4.c |  34 +
 .../c-c++-common/goacc/kernels-loop-annotation-5.c |  27 +
 .../c-c++-common/goacc/kernels-loop-annotation-6.c |  27 +
 .../c-c++-common/goacc/kernels-loop-annotation-7.c |  26 +
 .../c-c++-common/goacc/kernels-loop-annotation-8.c |  27 +
 .../c-c++-common/goacc/kernels-loop-annotation-9.c |  26 +
 .../c-c++-common/goacc/kernels-loop-data-2.c       |   1 +
 .../goacc/kernels-loop-data-enter-exit-2.c         |   1 +
 .../goacc/kernels-loop-data-enter-exit.c           |   1 +
 .../c-c++-common/goacc/kernels-loop-data-update.c  |   1 +
 .../c-c++-common/goacc/kernels-loop-data.c         |   1 +
 gcc/testsuite/c-c++-common/goacc/kernels-loop-g.c  |   1 +
 .../c-c++-common/goacc/kernels-loop-mod-not-zero.c |   1 +
 gcc/testsuite/c-c++-common/goacc/kernels-loop-n.c  |   1 +
 .../c-c++-common/goacc/kernels-loop-nest.c         |   1 +
 gcc/testsuite/c-c++-common/goacc/kernels-loop.c    |   1 +
 .../c-c++-common/goacc/kernels-one-counter-var.c   |   1 +
 .../goacc/kernels-parallel-loop-data-enter-exit.c  |   1 +
 .../c-c++-common/goacc/kernels-reduction.c         |   1 +
 gcc/tree.h                                         |   5 +
 54 files changed, 1603 insertions(+), 62 deletions(-)
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-1.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-10.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-11.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-12.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-13.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-14.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-15.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-16.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-17.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-18.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-19.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-2.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-20.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-21.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-22.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-3.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-4.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-5.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-6.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-7.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-8.c
 create mode 100644 gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-9.c

diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 6abfe4b..d7938ba 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1220,6 +1220,7 @@ extern enum omp_clause_default_kind c_omp_predetermined_sharing (tree);
 extern enum omp_clause_defaultmap_kind c_omp_predetermined_mapping (tree);
 extern tree c_omp_check_context_selector (location_t, tree);
 extern void c_omp_mark_declare_variant (location_t, tree, tree);
+extern void c_oacc_annotate_loops_in_kernels_regions (tree, tree (*) (tree));
 extern const char *c_omp_map_clause_name (tree, bool);
 
 /* Return next tree in the chain for chain_next walking of tree nodes.  */
diff --git a/gcc/c-family/c-omp.c b/gcc/c-family/c-omp.c
index d7cff0f..3c86f3f 100644
--- a/gcc/c-family/c-omp.c
+++ b/gcc/c-family/c-omp.c
@@ -35,7 +35,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "attribs.h"
 #include "gimplify.h"
 #include "langhooks.h"
-
+#include "tree-iterator.h"
 
 /* Complete a #pragma oacc wait construct.  LOC is the location of
    the #pragma.  */
@@ -694,6 +694,110 @@ c_omp_for_incr_canonicalize_ptr (location_t loc, tree decl, tree incr)
   return incr;
 }
 
+/* State of annotation traversal for FOR loops in kernels regions,
+   used to control processing and diagnostic messages that are deferred until
+   the entire loop has been scanned.  */
+enum annotation_state {
+  as_outer,
+  as_in_kernels_region,
+  as_in_kernels_loop,
+  /* The remaining state values represent conversion failures caught
+     while in as_in_kernels_loop state.  To test whether the traversal is
+     in the body of a kernels loop, use (state >= as_in_kernels_loop).  */
+  as_invalid_variable_type,
+  as_missing_initializer,
+  as_invalid_initializer,
+  as_missing_predicate,
+  as_invalid_predicate,
+  as_missing_increment,
+  as_invalid_increment,
+  as_explicit_annotation,
+  as_invalid_control_flow,
+  as_invalid_break,
+  as_invalid_return,
+  as_invalid_call,
+  as_invalid_modification
+};
+
+/* Structure used to hold state for automatic annotation of FOR loops
+   in kernels regions.  LOOP is the nearest enclosing loop, or
+   NULL_TREE if outside of a loop context.  VARS is a tree_list
+   containing the variables controlling LOOP's termination (the
+   induction variable and a possible limit variable).  STATE keeps
+   track of whether loop satisfies all criteria making it legal to
+   parallelize.  Otherwise, REASON is a statement that blocks
+   automatic parallelization, such as an unstructured jump or an
+   assignment to a variable in VARS, used for printing diagnostics.
+
+   These structures are chained through NEXT, which points to the
+   next-closest enclosing loop's or the kernels region's annotation info, if
+   any.  */
+
+struct annotation_info
+{
+  tree loop;
+  tree vars;
+  bool break_ok;
+  enum annotation_state state;
+  tree reason;
+  struct annotation_info *next;
+};
+
+/* Mark the current loop's INFO as not OK to annotate, recording STATE
+   and REASON for producing diagnostics later.  */
+
+static void
+do_not_annotate_loop (struct annotation_info *info,
+		      enum annotation_state state, tree reason)
+{
+  if (info->state == as_in_kernels_loop)
+    {
+      info->state = state;
+      info->reason = reason;
+    }
+}
+
+/* Mark the current loop identified by INFO and all of its ancestors (i.e.,
+   enclosing loops) as not OK to annotate.  Arguments are the same as
+   for do_not_annotate_loop.  */
+
+static void
+do_not_annotate_loop_nest (struct annotation_info *info,
+			   enum annotation_state state, tree reason)
+{
+  while (info != NULL)
+    {
+      do_not_annotate_loop (info, state, reason);
+      info = info->next;
+    }
+}
+
+/* If INFO is non-null, call do_not_annotate_loop with STATE and REASON
+   to record info for diagnosing an error later.  Otherwise emit an error now
+   at ELOCUS with message MSG and the optional arguments.  */
+
+static void annotation_error (struct annotation_info *,
+			      enum annotation_state, tree, location_t,
+			      const char *, ...) ATTRIBUTE_GCC_DIAG(5,6);
+static
+void annotation_error (struct annotation_info *info,
+			      enum annotation_state state,
+			      tree reason,
+			      location_t elocus,
+			      const char *msg, ...)
+{
+  if (info)
+    do_not_annotate_loop (info, state, reason);
+  else
+    {
+      auto_diagnostic_group d;
+      va_list ap;
+      va_start (ap, msg);
+      emit_diagnostic_valist (DK_ERROR, elocus, -1, msg, &ap);
+      va_end (ap);
+    }
+}
+
 /* Validate and generate OMP_FOR.
    DECLV is a vector of iteration variables, for each collapsed loop.
 
@@ -703,12 +807,19 @@ c_omp_for_incr_canonicalize_ptr (location_t loc, tree decl, tree incr)
    INITV, CONDV and INCRV are vectors containing initialization
    expressions, controlling predicates and increment expressions.
    BODY is the body of the loop and PRE_BODY statements that go before
-   the loop.  */
+   the loop.  FINAL_P is true if not inside a C++ template.
 
-tree
-c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
-		  tree orig_declv, tree initv, tree condv, tree incrv,
-		  tree body, tree pre_body, bool final_p)
+   INFO is null if called to parse an explicitly-annotated OMP for
+   loop, otherwise it holds state information for automatically
+   annotating a regular FOR loop in a kernels region.  In the former case,
+   malformed loops are hard errors; otherwise we just record the annotation
+   failure in INFO.  */
+
+static tree
+c_finish_omp_for_internal (location_t locus, enum tree_code code, tree declv,
+			   tree orig_declv, tree initv, tree condv, tree incrv,
+			   tree body, tree pre_body, bool final_p,
+			   struct annotation_info *info)
 {
   location_t elocus;
   bool fail = false;
@@ -732,12 +843,14 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
       if (!INTEGRAL_TYPE_P (TREE_TYPE (decl))
 	  && TREE_CODE (TREE_TYPE (decl)) != POINTER_TYPE)
 	{
-	  error_at (elocus, "invalid type for iteration variable %qE", decl);
+	  annotation_error (info, as_invalid_variable_type, decl, elocus,
+			    "invalid type for iteration variable %qE", decl);
 	  fail = true;
 	}
       else if (TYPE_ATOMIC (TREE_TYPE (decl)))
 	{
-	  error_at (elocus, "%<_Atomic%> iteration variable %qE", decl);
+	  annotation_error (info, as_invalid_variable_type, decl, elocus,
+			    "%<_Atomic%> iteration variable %qE", decl);
 	  fail = true;
 	  /* _Atomic iterator confuses stuff too much, so we risk ICE
 	     trying to diagnose it further.  */
@@ -753,7 +866,8 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
 	  init = DECL_INITIAL (decl);
 	  if (init == NULL)
 	    {
-	      error_at (elocus, "%qE is not initialized", decl);
+	      annotation_error (info, as_missing_initializer, decl, elocus,
+				"%qE is not initialized", decl);
 	      init = integer_zero_node;
 	      fail = true;
 	    }
@@ -774,7 +888,8 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
 
       if (cond == NULL_TREE)
 	{
-	  error_at (elocus, "missing controlling predicate");
+	  annotation_error (info, as_missing_predicate, NULL_TREE, elocus,
+			    "missing controlling predicate");
 	  fail = true;
 	}
       else
@@ -790,12 +905,14 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
 	  if (EXPR_HAS_LOCATION (cond))
 	    elocus = EXPR_LOCATION (cond);
 
-	  if (TREE_CODE (cond) == LT_EXPR
-	      || TREE_CODE (cond) == LE_EXPR
-	      || TREE_CODE (cond) == GT_EXPR
-	      || TREE_CODE (cond) == GE_EXPR
-	      || TREE_CODE (cond) == NE_EXPR
-	      || TREE_CODE (cond) == EQ_EXPR)
+	  enum tree_code condcode = TREE_CODE (cond);
+
+	  if (condcode == LT_EXPR
+	      || condcode == LE_EXPR
+	      || condcode == GT_EXPR
+	      || condcode == GE_EXPR
+	      || condcode == NE_EXPR
+	      || condcode == EQ_EXPR)
 	    {
 	      tree op0 = TREE_OPERAND (cond, 0);
 	      tree op1 = TREE_OPERAND (cond, 1);
@@ -815,79 +932,88 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
 	      if (TREE_CODE (op0) == NOP_EXPR
 		  && decl == TREE_OPERAND (op0, 0))
 		{
-		  TREE_OPERAND (cond, 0) = TREE_OPERAND (op0, 0);
-		  TREE_OPERAND (cond, 1)
-		    = fold_build1_loc (elocus, NOP_EXPR, TREE_TYPE (decl),
-				   TREE_OPERAND (cond, 1));
+		  op0 = TREE_OPERAND (op0, 0);
+		  op1 = fold_build1_loc (elocus, NOP_EXPR, TREE_TYPE (decl),
+					 op1);
 		}
 	      else if (TREE_CODE (op1) == NOP_EXPR
 		       && decl == TREE_OPERAND (op1, 0))
 		{
-		  TREE_OPERAND (cond, 1) = TREE_OPERAND (op1, 0);
-		  TREE_OPERAND (cond, 0)
-		    = fold_build1_loc (elocus, NOP_EXPR, TREE_TYPE (decl),
-				   TREE_OPERAND (cond, 0));
+		  op1 = TREE_OPERAND (op1, 0);
+		  op0 = fold_build1_loc (elocus, NOP_EXPR, TREE_TYPE (decl),
+					 op0);
 		}
 
-	      if (decl == TREE_OPERAND (cond, 0))
+	      if (decl == op0)
 		cond_ok = true;
-	      else if (decl == TREE_OPERAND (cond, 1))
+	      else if (decl == op1)
 		{
-		  TREE_SET_CODE (cond,
-				 swap_tree_comparison (TREE_CODE (cond)));
-		  TREE_OPERAND (cond, 1) = TREE_OPERAND (cond, 0);
-		  TREE_OPERAND (cond, 0) = decl;
+		  condcode = swap_tree_comparison (condcode);
+		  op1 = op0;
+		  op0 = decl;
 		  cond_ok = true;
 		}
 
-	      if (TREE_CODE (cond) == NE_EXPR
-		  || TREE_CODE (cond) == EQ_EXPR)
+	      if (condcode == NE_EXPR || condcode == EQ_EXPR)
 		{
 		  if (!INTEGRAL_TYPE_P (TREE_TYPE (decl)))
 		    {
-		      if (code == OACC_LOOP || TREE_CODE (cond) == EQ_EXPR)
+		      if (code == OACC_LOOP || condcode == EQ_EXPR)
 			cond_ok = false;
 		    }
-		  else if (operand_equal_p (TREE_OPERAND (cond, 1),
+		  else if (operand_equal_p (op1,
 					    TYPE_MIN_VALUE (TREE_TYPE (decl)),
 					    0))
-		    TREE_SET_CODE (cond, TREE_CODE (cond) == NE_EXPR
-					 ? GT_EXPR : LE_EXPR);
-		  else if (operand_equal_p (TREE_OPERAND (cond, 1),
+		    condcode = (condcode == NE_EXPR ? GT_EXPR : LE_EXPR);
+		  else if (operand_equal_p (op1,
 					    TYPE_MAX_VALUE (TREE_TYPE (decl)),
 					    0))
-		    TREE_SET_CODE (cond, TREE_CODE (cond) == NE_EXPR
-					 ? LT_EXPR : GE_EXPR);
-		  else if (code == OACC_LOOP || TREE_CODE (cond) == EQ_EXPR)
+		    condcode = (condcode == NE_EXPR ? LT_EXPR : GE_EXPR);
+		  else if (code == OACC_LOOP || condcode == EQ_EXPR)
 		    cond_ok = false;
 		}
 
-	      if (cond_ok && TREE_VEC_ELT (condv, i) != cond)
+	      if (cond_ok)
 		{
-		  tree ce = NULL_TREE, *pce = &ce;
-		  tree type = TREE_TYPE (TREE_OPERAND (cond, 1));
-		  for (tree c = TREE_VEC_ELT (condv, i); c != cond;
-		       c = TREE_OPERAND (c, 1))
+		  /* We postponed destructive changes to canonicalize
+		     cond until we're sure it is OK.  In the !error_p
+		     case where we are trying to transform a regular FOR_STMT
+		     to OMP_FOR, we don't want to destroy the original
+		     condition if we aren't going to be able to do the
+		     transformation anyway.  */
+		  TREE_SET_CODE (cond, condcode);
+		  TREE_OPERAND (cond, 0) = op0;
+		  TREE_OPERAND (cond, 1) = op1;
+
+		  if (TREE_VEC_ELT (condv, i) != cond)
 		    {
-		      *pce = build2 (COMPOUND_EXPR, type, TREE_OPERAND (c, 0),
-				     TREE_OPERAND (cond, 1));
-		      pce = &TREE_OPERAND (*pce, 1);
+		      tree ce = NULL_TREE, *pce = &ce;
+		      tree type = TREE_TYPE (op1);
+		      for (tree c = TREE_VEC_ELT (condv, i); c != cond;
+			   c = TREE_OPERAND (c, 1))
+			{
+			  *pce = build2 (COMPOUND_EXPR, type,
+					 TREE_OPERAND (c, 0), op1);
+			  pce = &TREE_OPERAND (*pce, 1);
+			}
+		      op1 = ce;
+		      TREE_VEC_ELT (condv, i) = cond;
 		    }
-		  TREE_OPERAND (cond, 1) = ce;
-		  TREE_VEC_ELT (condv, i) = cond;
 		}
 	    }
 
 	  if (!cond_ok)
 	    {
-	      error_at (elocus, "invalid controlling predicate");
+	      annotation_error (info, as_invalid_predicate, cond, elocus,
+				"invalid controlling predicate");
 	      fail = true;
 	    }
 	}
 
       if (incr == NULL_TREE)
 	{
-	  error_at (elocus, "missing increment expression");
+	  annotation_error (info, as_missing_increment, NULL_TREE, elocus,
+			    "missing increment expression");
 	  fail = true;
 	}
       else
@@ -986,9 +1112,11 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
 			      if (i == NULL_TREE
 				  || !operand_equal_p (unit, i, 0))
 				{
-				  error_at (elocus,
-					    "increment is not constant 1 or "
-					    "-1 for %<!=%> condition");
+				  annotation_error (info,
+						    as_invalid_increment,
+						    incr, elocus,
+						    "increment is not constant 1 or "
+						    "-1 for %<!=%> condition");
 				  fail = true;
 				}
 			    }
@@ -1004,9 +1132,10 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
 		    {
 		      if (!integer_onep (i) && !integer_minus_onep (i))
 			{
-			  error_at (elocus,
-				    "increment is not constant 1 or -1 for"
-				    " %<!=%> condition");
+			  annotation_error (info, as_invalid_increment,
+					    incr, elocus,
+					    "increment is not constant 1 or -1 for"
+					    " %<!=%> condition");
 			  fail = true;
 			}
 		    }
@@ -1018,7 +1147,8 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
 	    }
 	  if (!incr_ok)
 	    {
-	      error_at (elocus, "invalid increment expression");
+	      annotation_error (info, as_invalid_increment, incr,
+				elocus, "invalid increment expression");
 	      fail = true;
 	    }
 	}
@@ -1046,6 +1176,20 @@ c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
     }
 }
 
+/* External entry point to c_finish_omp_for_internal, called from the
+   parsers.  See above for description of the arguments.  */
+
+tree
+c_finish_omp_for (location_t locus, enum tree_code code, tree declv,
+		  tree orig_declv, tree initv, tree condv, tree incrv,
+		  tree body, tree pre_body, bool final_p)
+{
+  return c_finish_omp_for_internal (locus, code, declv,
+				    orig_declv, initv, condv, incrv,
+				    body, pre_body, final_p, NULL);
+}
+
+
 /* Type for passing data in between c_omp_check_loop_iv and
    c_omp_check_loop_iv_r.  */
 
@@ -2579,3 +2723,657 @@ c_omp_map_clause_name (tree clause, bool oacc)
     }
   return omp_clause_code_name[OMP_CLAUSE_CODE (clause)];
 }
+
+
+/* The following functions implement automatic recognition and annotation of
+   for loops in OpenACC kernels regions.  Inside a kernels region, a nest of
+   for loops that does not contain any annotated OpenACC loops, nor break
+   or goto statements or assignments to the variables controlling loop
+   termination, is converted to an OMP_FOR node with an "acc loop auto"
+   annotation on each loop.  This feature is controlled by
+   flag_openacc_kernels_annotate_loops.  */
+
+/* Check whether DECL is the declaration of a local variable (or function
+   parameter) of integral type that does not have its address taken.  */
+
+static bool
+is_local_var (tree decl)
+{
+  return ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
+	  && DECL_CONTEXT (decl) != NULL
+	  && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL
+	  && INTEGRAL_TYPE_P (TREE_TYPE (decl))
+	  && !TREE_ADDRESSABLE (decl));
+}
+
+/* EXP is a loop bound expression for a comparison against local
+   variable DECL.  Check whether this is potentially valid in an OpenACC loop
+   context, namely that it can be precomputed when entering the loop
+   construct per the OpenACC specification.  Local variables referenced
+   in both DECL and EXP that may not be modified in the body of the loop
+   are added to the list in INFO to be checked later.
+
+   FIXME: Ideally we would like to make this test permissive rather than
+   restrictive, and allow the later conversion of the "auto" attribute to
+   either "seq" or "independent" to make the determination using dataflow,
+   alias analysis, etc rather than a tree traversal.  But presently it does
+   not do that and always just hoists the loop bound expression.  So the
+   current implementation only considers expressions involving unmodified
+   local variables and constants, using a tree walk.  */
+
+static tree
+end_test_ok_for_annotation_r (tree *tp, int *walk_subtrees,
+			      void *data)
+{
+  tree exp = *tp;
+  struct annotation_info *info = (struct annotation_info *) data;
+
+  switch (TREE_CODE_CLASS (TREE_CODE (exp)))
+    {
+    case tcc_constant:
+      /* Constants are trivially known to be invariant.  */
+      return NULL_TREE;
+
+    case tcc_declaration:
+      if (is_local_var (exp))
+	{
+	  tree t;
+	  /* Add it to the list of variables that can't be modified in the
+	     loop, only if not already present.  */
+	  for (t = info->vars; t && TREE_VALUE (t) != exp;
+	       t = TREE_CHAIN (t))
+	    ;
+	  if (!t)
+	    info->vars = tree_cons (NULL_TREE, exp, info->vars);
+	  return NULL_TREE;
+	}
+      else if (TREE_CODE (exp) == VAR_DECL && TREE_READONLY (exp))
+	return NULL_TREE;
+      else if (TREE_CODE (exp) == FUNCTION_DECL)
+	return NULL_TREE;
+      break;
+
+    case tcc_unary:
+    case tcc_binary:
+    case tcc_comparison:
+      /* Allow arithmetic expressions and comparisons provided
+	 that the operands are good.  */
+      return NULL_TREE;
+
+    default:
+      /* Handle some special cases.  */
+      switch (TREE_CODE (exp))
+	{
+	case COND_EXPR:
+	case TRUTH_ANDIF_EXPR:
+	case TRUTH_ORIF_EXPR:
+	case TRUTH_AND_EXPR:
+	case TRUTH_OR_EXPR:
+	case TRUTH_XOR_EXPR:
+	case TRUTH_NOT_EXPR:
+	  /* ?: and boolean operators are OK.  */
+	  return NULL_TREE;
+
+	case CALL_EXPR:
+	  /* Allow calls to constant functions with invariant operands.  */
+	  {
+	    tree fndecl = get_callee_fndecl (exp);
+	    if (fndecl && TREE_READONLY (fndecl))
+	      return NULL_TREE;
+	  }
+	  break;
+
+	case ADDR_EXPR:
+	  /* We can expect addresses of things to be invariant.  */
+	  return NULL_TREE;
+
+	default:
+	  break;
+	}
+    }
+
+  /* Reject anything else.  */
+  *walk_subtrees = 0;
+  return exp;
+}
+
+static bool
+end_test_ok_for_annotation (tree decl, tree exp,
+			    struct annotation_info *info)
+{
+  /* Traversal returns NULL_TREE if all is well.  */
+  if (!walk_tree (&exp, end_test_ok_for_annotation_r, info, NULL))
+    {
+      /* So far, so good.  Check the decl against any variables collected
+	 in the exp.  */
+      tree t;
+      for (t = info->vars; t; t = TREE_CHAIN (t))
+	if (TREE_VALUE (t) == decl)
+	  return false;
+      info->vars = tree_cons (NULL_TREE, decl, info->vars);
+      return true;
+    }
+  return false;
+}
+
+/* The initializer for a FOR_STMT is sometimes wrapped in various other
+   language-specific tree structures.  We need a hook to unwrap them.
+   This function takes a tree argument and should return either a
+   MODIFY_EXPR, VAR_DECL, or NULL_TREE.  */
+
+static tree (*lang_specific_unwrap_initializer) (tree);
+
+/* Try to annotate the given NODE, which must be a FOR_STMT, with a
+   "#pragma acc loop auto" annotation.  In practice, this means
+   building an OMP_FOR node for it.  DECL and INIT are the
+   previously-verified iteration variable and initializer.  Annotating
+   the loop may fail, in which case INFO is used to record the cause
+   of the failure and the original loop remains unchanged.  This
+   function returns the transformed loop if the transformation
+   succeeded, the original node otherwise.  */
+
+static tree
+annotate_for_loop (tree node, tree decl, tree init,
+		   struct annotation_info *info)
+{
+  gcc_checking_assert (TREE_CODE (node) == FOR_STMT);
+
+  location_t loc = EXPR_LOCATION (node);
+  tree cond = FOR_COND (node);
+  tree incr = FOR_EXPR (node);
+
+  gcc_assert (decl);
+  gcc_assert (cond);
+  gcc_assert (decl && TREE_CODE (decl) == VAR_DECL);
+
+  /* The C++ frontend can wrap the increment two levels deep inside a
+     cleanup expression, but c_finish_omp_for does not care about that.  */
+  if (incr != NULL_TREE && TREE_CODE (incr) == CLEANUP_POINT_EXPR)
+    incr = TREE_OPERAND (TREE_OPERAND (incr, 0), 0);
+  tree body = FOR_BODY (node);
+
+  tree declv = make_tree_vec (1);
+  tree initv = make_tree_vec (1);
+  tree condv = make_tree_vec (1);
+  tree incrv = make_tree_vec (1);
+  TREE_VEC_ELT (declv, 0) = decl;
+  TREE_VEC_ELT (initv, 0) = init;
+  TREE_VEC_ELT (condv, 0) = cond;
+  TREE_VEC_ELT (incrv, 0) = incr;
+
+  /* Do the actual transformation.  This can still fail because
+     c_finish_omp_for has some stricter checks than we have performed up to
+     this point.  */
+  tree omp_for = c_finish_omp_for_internal (loc, OACC_LOOP, declv, NULL_TREE,
+					    initv, condv, incrv, body,
+					    NULL_TREE, false, info);
+  if (omp_for != NULL_TREE)
+    {
+      /* Add an auto clause, then return the new loop.  */
+      tree auto_clause = build_omp_clause (loc, OMP_CLAUSE_AUTO);
+      OMP_CLAUSE_CHAIN (auto_clause) = OMP_FOR_CLAUSES (omp_for);
+      OMP_FOR_CLAUSES (omp_for) = auto_clause;
+      return omp_for;
+    }
+
+  return node;
+}
+
+/* Forward declaration.  */
+static tree annotate_loops_in_kernels_regions (tree *, int *, void *);
+
+/* Given a FOR_STMT NODE that is a candidate for parallelization, check its
+   body for validity, then try to annotate it with
+   "#pragma oacc loop auto", possibly modifying the current node in place.
+   The INFO argument contains the traversal state at the point the loop
+   appears.  */
+
+static void
+check_and_annotate_for_loop (tree *nodeptr, tree_stmt_iterator *prev_tsi,
+			     struct annotation_info *info)
+{
+  tree node = *nodeptr;
+  gcc_assert (TREE_CODE (node) == FOR_STMT);
+  tree init = FOR_INIT_STMT (node);
+  tree cond = FOR_COND (node);
+  tree prev_stmt = NULL_TREE;
+  tree decl = NULL_TREE;
+  bool unlink_prev = false;
+  bool fix_decl = false;
+
+  /* This structure describes the current loop statement.  */
+  struct annotation_info loop_info
+    = { node, NULL_TREE, false, as_in_kernels_loop, NULL_TREE, info };
+
+  /* If we are in the body of an explicitly-annotated loop, do not add
+     annotations to this loop or any other nested loops.  */
+  if (info->state == as_explicit_annotation)
+    do_not_annotate_loop (&loop_info, as_explicit_annotation, info->reason);
+
+  /* We need to find the controlling variable for the loop in order
+     to detect whether it is modified in the body of the loop.
+     That is why we are doing some checks on the loop condition
+     that duplicate what c_finish_omp_for is doing.  */
+
+  /* First we need to find the decl and initializer for the
+     controlling variable.  Both the C and C++ front ends normally put
+     the initializer in the statement list just before the FOR_STMT
+     instead of in FOR_INIT_STMT.  If FOR_INIT_STMT happens to exist
+     but isn't a MODIFY_EXPR, give up.
+     handle it.  */
+
+  else if (init != NULL_TREE && TREE_CODE (init) != MODIFY_EXPR)
+    do_not_annotate_loop (&loop_info, as_invalid_initializer, NULL_TREE);
+
+  /* Examine the statement before the loop to see if it is a
+     valid initializer.  It must be either a MODIFY_EXPR or VAR_DECL,
+     possibly wrapped in language-specific structure.  */
+  else if (init == NULL_TREE && prev_tsi != NULL && tsi_stmt (*prev_tsi))
+    {
+      prev_stmt = tsi_stmt (*prev_tsi);
+
+      /* Call the language-specific hook to unwrap prev_stmt.  */
+      prev_stmt = (*lang_specific_unwrap_initializer) (prev_stmt);
+
+      /* See if we have a valid MODIFY_EXPR.  */
+      if (TREE_CODE (prev_stmt) == MODIFY_EXPR
+	  && is_local_var (TREE_OPERAND (prev_stmt, 0))
+	  && !TREE_SIDE_EFFECTS (TREE_OPERAND (prev_stmt, 1)))
+	{
+	  decl = TREE_OPERAND (prev_stmt, 0);
+	  init = prev_stmt;
+	  unlink_prev = true;
+	}
+      else if (is_local_var (prev_stmt)
+	       && !TREE_SIDE_EFFECTS (DECL_INITIAL (prev_stmt)))
+	{
+	  /* If the preceding statement is the declaration of the loop
+	     variable with its initialization, build an assignment
+	     expression for the loop's initializer.  */
+	  decl = prev_stmt;
+	  init = build2 (MODIFY_EXPR, TREE_TYPE (decl), decl,
+			 DECL_INITIAL (decl));
+	  /* We need to remove the initializer from the decl if we
+	     end up using the init we just built instead.  */
+	  fix_decl = true;
+	}
+    }
+
+  if (init == NULL_TREE || decl == NULL_TREE)
+    /* There is nothing we can do to find the correct init statement for
+       this loop.  */
+    do_not_annotate_loop (&loop_info, as_missing_initializer, NULL_TREE);
+
+  /* The condition must be a comparison of the decl we found in
+     the initializer against an expression that can be hoisted
+     outside the loop.  */
+  if (loop_info.state > as_in_kernels_loop)
+    /* Skip validating condition if we've already got an error.  */
+    ;
+  else if (cond == NULL_TREE)
+    do_not_annotate_loop (&loop_info, as_missing_predicate, NULL_TREE);
+  else if (TREE_CODE_CLASS (TREE_CODE (cond)) != tcc_comparison)
+    do_not_annotate_loop (&loop_info, as_invalid_predicate, cond);
+  else
+    {
+      tree limit_exp = NULL_TREE;
+
+      if (TREE_OPERAND (cond, 0) == decl)
+	limit_exp = TREE_OPERAND (cond, 1);
+      else if (TREE_OPERAND (cond, 1) == decl)
+	limit_exp = TREE_OPERAND (cond, 0);
+
+      if (!limit_exp
+	  || !end_test_ok_for_annotation (decl, limit_exp, &loop_info))
+	do_not_annotate_loop (&loop_info, as_invalid_predicate, cond);
+    }
+
+  /* Walk the body.  This will process any nested loops, so we have to do it
+     even if we have already rejected this loop as a candidate for
+     annotation.  */
+  walk_tree (&FOR_BODY (node), annotate_loops_in_kernels_regions,
+	     (void *) &loop_info, NULL);
+
+  if (loop_info.state == as_in_kernels_loop)
+    {
+      /* If the traversal of the loop and all nested loops didn't hit
+	 any problems, attempt the actual transformation.  If it
+	 succeeds, replace this node with the annotated loop.  */
+      tree result = annotate_for_loop (node, decl, init, &loop_info);
+      if (result != node)
+	{
+	  /* Success!  */
+	  *nodeptr = result;
+
+	  if (unlink_prev)
+	    /* We don't need the previous statement that we consumed
+	       as an initializer in the new OMP_FOR any more.  */
+	    tsi_delink (prev_tsi);
+
+	  if (fix_decl)
+	    /* We no longer need the initializer expression on the
+	       decl of the loop variable and don't want to duplicate
+	       it.  The kernels conversion pass would interpret it as
+	       a stray assignment in a gang-single region.  */
+	    DECL_INITIAL (decl) = NULL_TREE;
+
+	  return;
+	}
+    }
+
+  /* If we got here, we have a FOR_STMT we could not convert to an
+     OMP loop.  */
+
+  if (loop_info.state == as_invalid_return)
+    /* This is diagnosed elsewhere as a hard error, so no warning is
+       needed here.  */
+    return;
+
+  /* Issue warnings about other problems.  */
+  auto_diagnostic_group d;
+  if (warning_at (EXPR_LOCATION (node),
+		  OPT_Wopenacc_kernels_annotate_loops,
+		  "loop cannot be annotated for OpenACC parallelization"))
+    {
+      location_t locus;
+      if (loop_info.reason && EXPR_HAS_LOCATION (loop_info.reason))
+	locus = EXPR_LOCATION (loop_info.reason);
+      else
+	locus = EXPR_LOCATION (node);
+      switch (loop_info.state)
+	{
+	case as_invalid_variable_type:
+	  inform (locus, "invalid type for iteration variable %qE",
+		  loop_info.reason);
+	  break;
+	case as_missing_initializer:
+	  inform (locus, "missing iteration variable initializer");
+	  break;
+	case as_invalid_initializer:
+	  inform (locus, "unrecognized initializer");
+	  break;
+	case as_missing_predicate:
+	  inform (locus, "missing controlling predicate");
+	  break;
+	case as_invalid_predicate:
+	  inform (locus, "invalid controlling predicate");
+	  break;
+	case as_missing_increment:
+	  inform (locus, "missing increment expression");
+	  break;
+	case as_invalid_increment:
+	  inform (locus, "invalid increment expression");
+	  break;
+	case as_explicit_annotation:
+	  inform (locus, "explicit OpenACC annotation in loop nest");
+	  break;
+	case as_invalid_control_flow:
+	  inform (locus, "loop contains unstructured control flow");
+	  break;
+	case as_invalid_break:
+	  inform (locus, "loop contains %<break%> statement");
+	  break;
+	case as_invalid_call:
+	  inform (locus, "loop contains call to non-oacc function");
+	  break;
+	case as_invalid_modification:
+	  inform (locus, "invalid modification of controlling variable");
+	  break;
+	default:
+	  gcc_unreachable ();
+	}
+    }
+}
+
+/* Traversal function for walk_tree.  Visit the tree, finding OpenACC
+   kernels regions.  DATA is NULL if we are outside of a kernels region,
+   otherwise it is a pointer to the enclosing kernels region's
+   annotation_info struct.  If the traversal encounters a for loop inside a
+   kernels region that is a candidate for parallelization, annotate it
+   with OpenACC loop directives.  */
+
+static tree
+annotate_loops_in_kernels_regions (tree *nodeptr, int *walk_subtrees,
+				   void *data)
+{
+  tree node = *nodeptr;
+  struct annotation_info *info = (struct annotation_info *) data;
+  gcc_assert (info);
+
+  switch (TREE_CODE (node))
+    {
+    case OACC_KERNELS:
+      /* Recursively process the body of the kernels region in a new info
+	 scope.  */
+      if (info->state == as_outer)
+	{
+	  struct annotation_info nested_info
+	    = { NULL_TREE, NULL_TREE, true,
+		as_in_kernels_region, NULL_TREE, info };
+	  walk_tree (&OMP_BODY (node), annotate_loops_in_kernels_regions,
+		     (void *) &nested_info, NULL);
+	  *walk_subtrees = 0;
+	}
+      break;
+
+    case OACC_LOOP:
+      /* Do not try to add automatic OpenACC annotations inside manually
+	 annotated loops.  Presumably, the user avoided doing it on
+	 purpose; for example, all available levels of parallelism may
+	 have been used up.  However, assume that the combined construct
+	 "#pragma acc kernels loop" means to try to process the whole
+	 loop nest.
+	 Note that a single OACC_LOOP construct represents an entire set
+	 of collapsed loops so we do not have to deal explicitly with the
+	 collapse clause here, as the Fortran front end does.  */
+      if (info->state == as_in_kernels_region && OACC_LOOP_COMBINED (node))
+	{
+	  walk_tree (&OMP_BODY (node), annotate_loops_in_kernels_regions,
+		     (void *) info, NULL);
+	  *walk_subtrees = 0;
+	}
+      else
+	{
+	  struct annotation_info nested_info
+	    = { NULL_TREE, NULL_TREE, false, as_explicit_annotation,
+		node, info };
+	  if (info->state >= as_in_kernels_region)
+	    do_not_annotate_loop_nest (info, as_explicit_annotation,
+				       node);
+	  walk_tree (&OMP_BODY (node), annotate_loops_in_kernels_regions,
+		     (void *) &nested_info, NULL);
+	  *walk_subtrees = 0;
+	}
+      break;
+
+    case FOR_STMT:
+      /* Try to annotate the loop if we are in a kernels region.
+	 This will do a recursive traversal of the loop body in a new
+	 info scope.  */
+      if (info->state >= as_in_kernels_region)
+	{
+	  check_and_annotate_for_loop (nodeptr, NULL, info);
+	  *walk_subtrees = 0;
+	}
+      break;
+
+    case LABEL_EXPR:
+      /* Possibly unstructured control flow.  Unless we perform further
+	 analyses, we must assume that such control flow may enter the
+	 current loop.  In this case, we must not parallelize the loop.  */
+      if (info->state >= as_in_kernels_loop
+	  && TREE_USED (LABEL_EXPR_LABEL (node)))
+	do_not_annotate_loop_nest (info, as_invalid_control_flow, node);
+      break;
+
+    case GOTO_EXPR:
+      /* Possibly unstructured control flow.  Unless we perform further
+	 analyses, we must assume that such control flow may leave the
+	 current loop.  In this case, we must not parallelize the loop.  */
+      if (info->state >= as_in_kernels_loop)
+	do_not_annotate_loop_nest (info, as_invalid_control_flow, node);
+      break;
+
+    case BREAK_STMT:
+      /* A break statement.  Whether or not this is valid depends on the
+	 enclosing context.  */
+      if (info->state >= as_in_kernels_loop && !info->break_ok)
+	do_not_annotate_loop (info, as_invalid_break, node);
+      break;
+
+    case RETURN_EXPR:
+      /* A return leaves the entire loop nest.  */
+      if (info->state >= as_in_kernels_loop)
+	do_not_annotate_loop_nest (info, as_invalid_return, node);
+      break;
+
+    case CALL_EXPR:
+      /* Direct function calls to builtins and functions marked as
+	 OpenACC routines are allowed.  Reject indirect calls or calls
+	 to non-routines.  */
+      if (info->state >= as_in_kernels_loop)
+	{
+	  tree fn = CALL_EXPR_FN (node), fn_decl = NULL_TREE;
+	  if (fn != NULL_TREE && TREE_CODE (fn) == FUNCTION_DECL)
+	    fn_decl = fn;
+	  else if (fn != NULL_TREE && TREE_CODE (fn) == ADDR_EXPR)
+	    {
+	      tree fn_op = TREE_OPERAND (fn, 0);
+	      if (fn_op != NULL_TREE && TREE_CODE (fn_op) == FUNCTION_DECL)
+		fn_decl = fn_op;
+	    }
+	  if (fn_decl == NULL_TREE)
+	    do_not_annotate_loop_nest (info, as_invalid_call, node);
+	  else if (!fndecl_built_in_p (fn_decl, BUILT_IN_NORMAL)
+		   && !lookup_attribute ("oacc function",
+					 DECL_ATTRIBUTES (fn_decl)))
+	    do_not_annotate_loop_nest (info, as_invalid_call, node);
+	}
+      break;
+
+    case MODIFY_EXPR:
+      /* See if this assignment's LHS is one of the variables that must
+	 not be modified in the loop body because they control termination
+	 of the loop (or an enclosing loop in the nest).  */
+      if (info->state >= as_in_kernels_loop)
+	{
+	  tree lhs = TREE_OPERAND (node, 0);
+	  if (!is_local_var (lhs))
+	    /* Early exit: This cannot be a variable we care about.  */
+	    break;
+	  /* Walk up the loop stack.  Invalidate the ones controlled by this
+	     variable.  There may be several, if this variable is the common
+	     iteration limit for several nested loops.  */
+	  for (struct annotation_info *outer_loop = info; outer_loop != NULL;
+	       outer_loop = outer_loop->next)
+	    for (tree t = outer_loop->vars; t != NULL_TREE; t = TREE_CHAIN (t))
+	      if (TREE_VALUE (t) == lhs)
+		{
+		  do_not_annotate_loop (outer_loop,
+					as_invalid_modification,
+					node);
+		  break;
+		}
+	}
+      break;
+
+    case SWITCH_STMT:
+      /* Needs special handling to allow break in the body.  */
+      if (info->state >= as_in_kernels_loop)
+	{
+	  bool save_break_ok = info->break_ok;
+
+	  walk_tree (&SWITCH_STMT_COND (node),
+		     annotate_loops_in_kernels_regions,
+		     (void *) info, NULL);
+	  info->break_ok = true;
+	  walk_tree (&SWITCH_STMT_BODY (node),
+		     annotate_loops_in_kernels_regions,
+		     (void *) info, NULL);
+	  info->break_ok = save_break_ok;
+	  *walk_subtrees = 0;
+	}
+      break;
+
+    case WHILE_STMT:
+      /* Needs special handling to allow break in the body.  */
+      if (info->state >= as_in_kernels_loop)
+	{
+	  bool save_break_ok = info->break_ok;
+
+	  walk_tree (&WHILE_COND (node), annotate_loops_in_kernels_regions,
+		     (void *) info, NULL);
+	  info->break_ok = true;
+	  walk_tree (&WHILE_BODY (node), annotate_loops_in_kernels_regions,
+		     (void *) info, NULL);
+	  info->break_ok = save_break_ok;
+	  *walk_subtrees = 0;
+	}
+      break;
+
+    case DO_STMT:
+      /* Needs special handling to allow break in the body.  */
+      if (info->state >= as_in_kernels_loop)
+	{
+	  bool save_break_ok = info->break_ok;
+
+	  walk_tree (&DO_COND (node), annotate_loops_in_kernels_regions,
+		     (void *) info, NULL);
+	  info->break_ok = true;
+	  walk_tree (&DO_BODY (node), annotate_loops_in_kernels_regions,
+		     (void *) info, NULL);
+	  info->break_ok = save_break_ok;
+	  *walk_subtrees = 0;
+	}
+      break;
+
+    case STATEMENT_LIST:
+      /* We iterate over these explicitly so that we can track the previous
+	 statement in the chain.  It may be the initializer for a following
+	 FOR_STMT node.  */
+      if (info->state >= as_in_kernels_region)
+	{
+	  tree_stmt_iterator i = tsi_start (node);
+	  tree_stmt_iterator prev, *prev_tsi = NULL;
+	  while (!tsi_end_p (i))
+	    {
+	      tree *stmtptr = tsi_stmt_ptr (i);
+	      if (TREE_CODE (*stmtptr) == FOR_STMT)
+		{
+		  check_and_annotate_for_loop (stmtptr, prev_tsi, info);
+		  *walk_subtrees = 0;
+		}
+	      else
+		walk_tree (stmtptr, annotate_loops_in_kernels_regions,
+			   (void *) info, NULL);
+	      prev = i;
+	      prev_tsi = &prev;
+	      tsi_next (&i);
+	    }
+	  *walk_subtrees = 0;
+	}
+      break;
+
+    default:
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+/* Find for loops in OpenACC kernels regions that do not have OpenACC
+   annotations but look like they might benefit from automatic
+   parallelization.  Convert them from FOR_STMT to OMP_FOR nodes and
+   add the equivalent of "#pragma acc loop auto" annotations for them.
+   Assumes flag_openacc_kernels_annotate_loops is set.  */
+
+void
+c_oacc_annotate_loops_in_kernels_regions (tree decl,
+					  tree (*unwrap_fn) (tree))
+{
+  struct annotation_info info
+    = { NULL_TREE, NULL_TREE, true, as_outer, NULL_TREE, NULL };
+  lang_specific_unwrap_initializer = unwrap_fn;
+  walk_tree (&DECL_SAVED_TREE (decl), annotate_loops_in_kernels_regions,
+	     (void *) &info, NULL);
+}
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index c1d8fd3..b146aad 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -975,6 +975,10 @@ Wold-style-definition
 C ObjC Var(warn_old_style_definition) Init(-1) Warning
 Warn if an old-style parameter definition is used.
 
+Wopenacc-kernels-annotate-loops
+C ObjC C++ ObjC++ Warning Var(warn_openacc_kernels_annotate_loops) Init(0)
+Warn about loops in OpenACC kernels regions that cannot be parallelized.
+
 Wopenmp-simd
 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
 Warn if a simd directive is overridden by the vectorizer cost model.
@@ -1744,6 +1748,10 @@ fopenacc-dim=
 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
 Specify default OpenACC compute dimensions.
 
+fopenacc-kernels-annotate-loops
+C ObjC C++ ObjC++ LTO Optimization Var(flag_openacc_kernels_annotate_loops) Init(1)
+Automatically parallelize unannotated loops in OpenACC kernels regions.
+
 fopenmp
 C ObjC C++ ObjC++ LTO Var(flag_openmp)
 Enable OpenMP (implies -frecursive in Fortran).
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 8204db2..02b7f2f 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -9885,6 +9885,29 @@ temp_pop_parm_decls (void)
   pop_scope ();
 }
 
+/* Function passed to c_oacc_annotate_loop_in_kernels_regions to do
+   language-specific unwrapping of an initializer expression.  */
+static tree
+c_unwrap_for_init (tree x)
+{
+  if (!x)
+    return NULL_TREE;
+
+  while (true)
+    switch (TREE_CODE (x))
+      {
+      case MODIFY_EXPR:
+      case VAR_DECL:
+	return x;
+
+      case DECL_EXPR:
+	x = TREE_OPERAND (x, 0);
+	break;
+
+      default:
+	return NULL_TREE;
+      }
+}
 
 /* Finish up a function declaration and compile that function
    all the way to assembler language output.  Then free the storage
@@ -9987,6 +10010,11 @@ finish_function (location_t end_loc)
   if (warn_unused_parameter)
     do_warn_unused_parameter (fndecl);
 
+  /* If requested, automatically annotate suitable loops in OpenACC kernels
+     regions with OpenACC loop annotations to allow auto-parallelization.  */
+  if (flag_openacc && flag_openacc_kernels_annotate_loops)
+    c_oacc_annotate_loops_in_kernels_regions (fndecl, c_unwrap_for_init);
+
   /* Store the end of the function, so that we get good line number
      info for the epilogue.  */
   cfun->function_end_locus = end_loc;
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 2e6775a..12fb4b7 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -16831,6 +16831,7 @@ c_parser_oacc_loop (location_t loc, c_parser *parser, char *p_name,
 		    omp_clause_mask mask, tree *cclauses, bool *if_p)
 {
   bool is_parallel = ((mask >> PRAGMA_OACC_CLAUSE_REDUCTION) & 1) == 1;
+  bool is_combined = (cclauses != NULL);
 
   strcat (p_name, " loop");
   mask |= OACC_LOOP_CLAUSE_MASK;
@@ -16849,6 +16850,8 @@ c_parser_oacc_loop (location_t loc, c_parser *parser, char *p_name,
   tree block = c_begin_compound_stmt (true);
   tree stmt = c_parser_omp_for_loop (loc, parser, OACC_LOOP, clauses, NULL,
 				     if_p);
+  if (stmt && stmt != error_mark_node)
+    OACC_LOOP_COMBINED (stmt) = is_combined;
   block = c_end_compound_stmt (loc, block, true);
   add_stmt (block);
 
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 31d6874..2d83c41 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -16960,6 +16960,45 @@ emit_coro_helper (tree helper)
   expand_or_defer_fn (helper);
 }
 
+
+/* Function passed to c_oacc_annotate_loop_in_kernels_regions to do
+   language-specific unwrapping of an initializer expression.  */
+static tree
+cp_unwrap_for_init (tree x)
+{
+  if (!x)
+    return NULL_TREE;
+
+  while (true)
+    switch (TREE_CODE (x))
+      {
+      case MODIFY_EXPR:
+      case VAR_DECL:
+	return x;
+
+      case CLEANUP_POINT_EXPR:
+	x = TREE_OPERAND (x, 0);
+	break;
+
+      case EXPR_STMT:
+	x = TREE_OPERAND (x, 0);
+	break;
+
+      case DECL_EXPR:
+	x = TREE_OPERAND (x, 0);
+	break;
+
+      case CONVERT_EXPR:
+	if (TREE_TYPE (x) != void_type_node)
+	  return NULL_TREE;
+	x = TREE_OPERAND (x, 0);
+	break;
+
+      default:
+	return NULL_TREE;
+      }
+}
+
 /* Finish up a function declaration and compile that function
    all the way to assembler language output.  The free the storage
    for the function definition. INLINE_P is TRUE if we just
@@ -17264,6 +17303,11 @@ finish_function (bool inline_p)
       && !DECL_CLONED_FUNCTION_P (fndecl))
     do_warn_unused_parameter (fndecl);
 
+  /* If requested, automatically annotate suitable loops in OpenACC kernels
+     regions with OpenACC loop annotations to allow auto-parallelization.  */
+  if (flag_openacc && flag_openacc_kernels_annotate_loops)
+    c_oacc_annotate_loops_in_kernels_regions (fndecl, cp_unwrap_for_init);
+
   /* Genericize before inlining.  */
   if (!processing_template_decl
       && !DECL_IMMEDIATE_FUNCTION_P (fndecl)
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 9849e59..1a11f2b 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -41281,6 +41281,7 @@ cp_parser_oacc_loop (cp_parser *parser, cp_token *pragma_tok, char *p_name,
 		     omp_clause_mask mask, tree *cclauses, bool *if_p)
 {
   bool is_parallel = ((mask >> PRAGMA_OACC_CLAUSE_REDUCTION) & 1) == 1;
+  bool is_combined = (cclauses != NULL);
 
   strcat (p_name, " loop");
   mask |= OACC_LOOP_CLAUSE_MASK;
@@ -41299,6 +41300,8 @@ cp_parser_oacc_loop (cp_parser *parser, cp_token *pragma_tok, char *p_name,
   tree block = begin_omp_structured_block ();
   int save = cp_parser_begin_omp_structured_block (parser);
   tree stmt = cp_parser_omp_for_loop (parser, OACC_LOOP, clauses, NULL, if_p);
+  if (stmt && stmt != error_mark_node)
+    OACC_LOOP_COMBINED (stmt) = is_combined;
   cp_parser_end_omp_structured_block (parser, save);
   add_stmt (finish_omp_structured_block (block));
 
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 107d39d..efdb393 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -4900,6 +4900,10 @@ handle_omp_array_sections_1 (tree c, tree t, vec<tree> &types,
     length = mark_rvalue_use (length);
   /* We need to reduce to real constant-values for checks below.  */
   if (length)
+    STRIP_NOPS (length);
+  if (low_bound)
+    STRIP_NOPS (low_bound);
+  if (length)
     length = fold_simple (length);
   if (low_bound)
     low_bound = fold_simple (low_bound);
@@ -5204,6 +5208,11 @@ handle_omp_array_sections (tree c, enum c_omp_region_type ort)
 	  tree low_bound = TREE_PURPOSE (t);
 	  tree length = TREE_VALUE (t);
 
+	  if (length)
+	    STRIP_NOPS (length);
+	  if (low_bound)
+	    STRIP_NOPS (low_bound);
+
 	  i--;
 	  if (low_bound
 	      && TREE_CODE (low_bound) == INTEGER_CST
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index bca8c85..af83a5f 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -348,7 +348,8 @@ Objective-C and Objective-C++ Dialects}.
 -Wmissing-include-dirs  -Wmissing-noreturn  -Wno-missing-profile @gol
 -Wno-multichar  -Wmultistatement-macros  -Wnonnull  -Wnonnull-compare @gol
 -Wnormalized=@r{[}none@r{|}id@r{|}nfc@r{|}nfkc@r{]} @gol
--Wnull-dereference  -Wno-odr  -Wopenmp-simd  @gol
+-Wnull-dereference  -Wno-odr @gol
+-Wopenacc-kernels-annotate-loops  -Wopenmp-simd @gol
 -Wno-overflow  -Woverlength-strings  -Wno-override-init-side-effects @gol
 -Wpacked  -Wno-packed-bitfield-compat  -Wpacked-not-aligned  -Wpadded @gol
 -Wparentheses  -Wno-pedantic-ms-format @gol
@@ -500,7 +501,8 @@ Objective-C and Objective-C++ Dialects}.
 -fmerge-constants  -fmodulo-sched  -fmodulo-sched-allow-regmoves @gol
 -fmove-loop-invariants  -fno-branch-count-reg @gol
 -fno-defer-pop  -fno-fp-int-builtin-inexact  -fno-function-cse @gol
--fno-guess-branch-probability  -fno-inline  -fno-math-errno  -fno-peephole @gol
+-fno-guess-branch-probability  -fno-inline  -fno-math-errno @gol
+-fno-openacc-kernels-annotate-loops  -fno-peephole @gol
 -fno-peephole2  -fno-printf-return-value  -fno-sched-interblock @gol
 -fno-sched-spec  -fno-signed-zeros @gol
 -fno-toplevel-reorder  -fno-trapping-math  -fno-zero-initialized-in-bss @gol
@@ -8305,6 +8307,13 @@ Do not warn about compile-time overflow in constant expressions.
 Warn about One Definition Rule violations during link-time optimization.
 Enabled by default.
 
+@item -Wopenacc-kernels-annotate-loops
+@opindex Wopenacc-kernels-annotate-loops
+@opindex Wno-Wopenacc-kernels-annotate-loops
+Warn about @code{for} (C/C++) or @code{DO} (Fortran) loops in OpenACC
+kernels regions that cannot be automatically annotated for
+parallelization with @option{-fopenacc-kernels-annotate-loops}.
+
 @item -Wopenmp-simd
 @opindex Wopenmp-simd
 @opindex Wno-openmp-simd
@@ -13647,6 +13656,27 @@ approximation is enabled.  The default value is 2.
 
 @end table
 
+@item -fno-openacc-kernels-annotate-loops
+@opindex fno-openacc-kernels-annotate-loops
+@opindex fopenacc-kernels-annotate-loops
+@cindex kernels regions, OpenACC
+Disable automatic parallelization of unannotated loops in OpenACC
+kernels regions.  The default is to attempt to add implicit
+@code{acc loop auto} annotations to loops in kernels regions if
+@option{-fopenacc} is enabled.
+
+Note that you can use @option{-Wopenacc-kernels-annotate-loops} to
+diagnose @code{for} loops that cannot be automatically annotated
+(@pxref{Warning Options}).  Reasons why automatic loop annotations
+cannot be applied include premature exits, calls to functions without
+an @code{openacc routine} annotation, or unstructured control flow in
+the loop body.  In C and C++, the loop variable initialization, end
+test, and increment expressions must additionally conform to
+restrictions similar to those for explicitly-annotated loops, and the
+loop variable must not be otherwise modified in the body of the loop.
+An explicit @code{acc loop} annotation disables automatic annotations
+on any nested or containing loops.
+
 @end table
 
 @node Instrumentation Options
diff --git a/gcc/testsuite/c-c++-common/goacc/classify-kernels-unparallelized.c b/gcc/testsuite/c-c++-common/goacc/classify-kernels-unparallelized.c
index d4c4b2c..a6e2d0b 100644
--- a/gcc/testsuite/c-c++-common/goacc/classify-kernels-unparallelized.c
+++ b/gcc/testsuite/c-c++-common/goacc/classify-kernels-unparallelized.c
@@ -2,6 +2,7 @@
    OpenACC kernels.  */
 
 /* { dg-additional-options "-O2" }
+   { dg-additional-options "-fno-openacc-kernels-annotate-loops" }
    { dg-additional-options "-fopt-info-optimized-omp" }
    { dg-additional-options "-fdump-tree-ompexp" }
    { dg-additional-options "-fdump-tree-parloops1-all" }
diff --git a/gcc/testsuite/c-c++-common/goacc/classify-kernels.c b/gcc/testsuite/c-c++-common/goacc/classify-kernels.c
index 16e9b9e..bb21c9c 100644
--- a/gcc/testsuite/c-c++-common/goacc/classify-kernels.c
+++ b/gcc/testsuite/c-c++-common/goacc/classify-kernels.c
@@ -2,6 +2,7 @@
    kernels.  */
 
 /* { dg-additional-options "-O2" }
+   { dg-additional-options "-fno-openacc-kernels-annotate-loops" }
    { dg-additional-options "-fopt-info-optimized-omp" }
    { dg-additional-options "-fdump-tree-ompexp" }
    { dg-additional-options "-fdump-tree-parloops1-all" }
diff --git a/gcc/testsuite/c-c++-common/goacc/combined-directives.c b/gcc/testsuite/c-c++-common/goacc/combined-directives.c
index c2a3c57..2519f23 100644
--- a/gcc/testsuite/c-c++-common/goacc/combined-directives.c
+++ b/gcc/testsuite/c-c++-common/goacc/combined-directives.c
@@ -110,7 +110,7 @@ test ()
 // { dg-final { scan-tree-dump-times "acc loop worker" 2 "gimple" } }
 // { dg-final { scan-tree-dump-times "acc loop vector" 2 "gimple" } }
 // { dg-final { scan-tree-dump-times "acc loop seq" 2 "gimple" } }
-// { dg-final { scan-tree-dump-times "acc loop auto" 2 "gimple" } }
+// { dg-final { scan-tree-dump-times "acc loop auto" 6 "gimple" } }
 // { dg-final { scan-tree-dump-times "acc loop tile.2, 3" 2 "gimple" } }
 // { dg-final { scan-tree-dump-times "acc loop independent private.i" 2 "gimple" } }
 // { dg-final { scan-tree-dump-times "private.z" 2 "gimple" } }
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-counter-var-redundant-load.c b/gcc/testsuite/c-c++-common/goacc/kernels-counter-var-redundant-load.c
index 0304254..c37152c 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-counter-var-redundant-load.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-counter-var-redundant-load.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-dom3" } */
 
 #include <stdlib.h>
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-counter-vars-function-scope.c b/gcc/testsuite/c-c++-common/goacc/kernels-counter-vars-function-scope.c
index c475333..b1f4302 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-counter-vars-function-scope.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-counter-vars-function-scope.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction-n.c b/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction-n.c
index 8f7f415..e87aab3 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction-n.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction-n.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fopt-info-optimized-omp" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction.c b/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction.c
index c11d36f..2323857 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-double-reduction.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fopt-info-optimized-omp" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c
index acef6a1..adca30b 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-3.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-3.c
index 75e2bb7..5f16085 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-3.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-3.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-1.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-1.c
new file mode 100644
index 0000000..c7b5ac8
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-1.c
@@ -0,0 +1,26 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that all loops in the nest are annotated.  */
+
+void f (float a[16][16], float b[16][16], float c[16][16])
+{
+  int i, j, k;
+
+#pragma acc kernels copyin(a[0:16][0:16], b[0:16][0:16]) copyout(c[0:16][0:16])
+  {
+    for (i = 0; i < 16; i++) {
+      for (j = 0; j < 16; j++) {
+	float t = 0;
+	for (k = 0; k < 16; k++)
+	  t += a[i][k] * b[k][j];
+	c[i][j] = t;
+      }
+    }
+  }
+
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 3 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-10.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-10.c
new file mode 100644
index 0000000..58b41d2
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-10.c
@@ -0,0 +1,32 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a random goto in the body can't be annotated.  */
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)	/* { dg-warning "loop cannot be annotated" } */
+      {
+	if (a[i] < 0)
+	  {
+	    t = 0;
+	    goto bad;
+	  }
+	t += a[i] * b[i];
+      }
+  bad:
+    ;
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-11.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-11.c
new file mode 100644
index 0000000..e9d2ef4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-11.c
@@ -0,0 +1,27 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a random label in the body triggers a warning.  */
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i = n - 1;
+
+#pragma acc kernels
+  {
+    goto spaghetti;
+    for (i = 0; i < n; i++)	/* { dg-warning "loop cannot be annotated" } */
+      {
+      spaghetti:
+	t += a[i] * b[i];
+      }
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-12.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-12.c
new file mode 100644
index 0000000..ba408bc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-12.c
@@ -0,0 +1,28 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that in a situation with nested loops, a problem that prevents
+   annotation of the inner loop only still allows the outer loop to be
+   annotated.  */
+
+float f (float *a, float *b, int n)
+{
+  float t = 0;
+
+#pragma acc kernels
+  {
+    for (int i = 0; i < n; i++)
+      for (int j = 0; j <= i; j++)  /* { dg-warning "loop cannot be annotated" } */
+       {
+         if (a[i] < 0 || b[j] < 0)
+           j = i;
+         else
+           t += a[i] * b[j];
+       }
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-13.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-13.c
new file mode 100644
index 0000000..64433e8
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-13.c
@@ -0,0 +1,27 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that in a situation with nested loops, a problem that prevents
+   annotation of the outer loop only still allows the inner loop to be
+   annotated.  */
+
+float f (float *a, float *b, int n)
+{
+  float t = 0;
+
+#pragma acc kernels
+  {
+    for (int i = 0; i < n; i++)	  /* { dg-warning "loop cannot be annotated" } */
+      {
+	if (a[i] < 0)
+	  n = i;
+	for (int j = 0; j <= i; j++)
+	  t += a[i] * b[j];
+      }
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-14.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-14.c
new file mode 100644
index 0000000..379e6ba
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-14.c
@@ -0,0 +1,22 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that an explicit annotation on an outer loop suppresses annotation
+   of inner loops, and produces a diagnostic.  */
+
+void f (float *a, float *b)
+{
+  float t = 0;
+
+#pragma acc kernels
+  {
+#pragma acc loop seq
+    for (int l = 0; l < 20; l++)
+      for (int m = 0; m < 20; m++)	/* { dg-warning "loop cannot be annotated" } */
+        b[m] = a[m];
+  }
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-15.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-15.c
new file mode 100644
index 0000000..9a2a7ca
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-15.c
@@ -0,0 +1,22 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that an explicit annotation on an inner loop suppresses annotation
+   of outer loops, and produces a diagnostic.  */
+
+void f (float *a, float *b)
+{
+  float t = 0;
+
+#pragma acc kernels
+  {
+    for (int l = 0; l < 20; l++)	/* { dg-warning "loop cannot be annotated" } */
+#pragma acc loop seq
+      for (int m = 0; m < 20; m++)
+        b[m] = a[m];
+  }
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-16.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-16.c
new file mode 100644
index 0000000..075f897
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-16.c
@@ -0,0 +1,26 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a modification of the loop variable in the
+   body cannot be annotated.  */
+
+float f (float *a, float *b, int n)
+{
+  float t = 0;
+
+#pragma acc kernels
+  {
+    for (int i = 0; i < n; i++)	/* { dg-warning "loop cannot be annotated" } */
+      {
+	if (a[i] < 0 || b[i] < 0)
+	  i = n;
+	else
+	  t += a[i] * b[i];
+      }
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-17.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-17.c
new file mode 100644
index 0000000..5076789
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-17.c
@@ -0,0 +1,26 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a modification of the loop iteration count
+   variable in the body cannot be annotated.  */
+
+float f (float *a, float *b, int n)
+{
+  float t = 0;
+
+#pragma acc kernels
+  {
+    for (int i = 0; i < n; i++)	/* { dg-warning "loop cannot be annotated" } */
+      {
+	if (a[i] < 0 || b[i] < 0)
+	  n = i;
+	else
+	  t += a[i] * b[i];
+      }
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-18.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-18.c
new file mode 100644
index 0000000..89ec644
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-18.c
@@ -0,0 +1,18 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that "acc kernels loop" directive causes annotation of the entire
+   loop nest.  */
+
+void f (float *a, float *b)
+{
+#pragma acc kernels loop
+  for (int k = 0; k < 20; k++)
+    for (int l = 0; l < 20; l++)
+      for (int m = 0; m < 20; m++)
+	b[m] = a[m];
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 2 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-19.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-19.c
new file mode 100644
index 0000000..77a3b7a
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-19.c
@@ -0,0 +1,19 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that "acc kernels loop" directive causes annotation of the entire
+   loop nest in the presence of a collapse clause.  */
+
+void f (float *a, float *b)
+{
+#pragma acc kernels loop collapse(2)
+  for (int k = 0; k < 20; k++)
+    for (int l = 0; l < 20; l++)
+      for (int m = 0; m < 20; m++)
+	b[m] = a[m];
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop collapse.2." 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-2.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-2.c
new file mode 100644
index 0000000..9e0a946
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-2.c
@@ -0,0 +1,21 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a variable bound can be annotated.  */
+
+float f (float *a, float *b, int n)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)
+      t += a[i] * b[i];
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-20.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-20.c
new file mode 100644
index 0000000..5e3f028
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-20.c
@@ -0,0 +1,23 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that calls to built-in functions don't inhibit kernels loop
+   annotation.  */
+
+void foo (int n, int *input, int *out1, int *out2)
+{
+#pragma acc kernels
+  {
+    int i;
+
+    for (i = 0; i < n; i++)
+      {
+	out1[i] = __builtin_clz (input[i]);
+	out2[i] = __builtin_popcount (input[i]);
+      }
+  }
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-21.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-21.c
new file mode 100644
index 0000000..f87444e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-21.c
@@ -0,0 +1,42 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test for rejecting annotation on loops that have various subexpressions
+   in the loop end test that are not loop-invariant.  */
+
+extern int g (int);
+extern int x;
+extern int gg (int, int) __attribute__ ((const));
+
+void f (float *a, float *b, int n)
+{
+
+  int j;
+#pragma acc kernels
+  {
+    /* Non-constant function call.  */
+    for (int i = 0; i < g(n); i++)	/* { dg-warning "loop cannot be annotated" } */
+      a[i] = b[i];
+
+    /* Global variable.  */
+    for (int i = x; i < n + x; i++)	/* { dg-warning "loop cannot be annotated" } */
+      a[i] = b[i];
+
+    /* Explicit reference to the loop variable.  */
+    for (int i = 0; i < gg (i, n); i++)	/* { dg-warning "loop cannot be annotated" } */
+      a[i] = b[i];
+
+    /* Reference to a variable that is modified in the body of the loop.  */
+    j = 0;
+    for (int i = 0; i < gg (j, n); i++)	/* { dg-warning "loop cannot be annotated" } */
+      {
+	a[i] = b[i];
+	j = i;
+      }
+
+  }
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-22.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-22.c
new file mode 100644
index 0000000..6a5099d
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-22.c
@@ -0,0 +1,41 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test for accepting annotation on loops that have various forms of
+   loop-invariant expressions in their end test.  */
+
+extern const int x;
+extern int g (int) __attribute__ ((const));
+
+void f (float *a, float *b, int n)
+{
+
+  int j;
+#pragma acc kernels
+  {
+    /* Reversed form of comparison.  */
+    for (int i = 0; n >= i; i++)
+      a[i] = b[i];
+    
+    /* Constant function call.  */
+    for (int i = 0; i < g(n); i++)
+      a[i] = b[i];
+
+    /* Constant global variable.  */
+    for (int i = 0; i < x; i++)
+      a[i] = b[i];
+
+    /* Complicated expression involving conditionals, etc. */
+    for (int i = 0; i < ((x == 4) ? (n << 2) : (n << 3)); i++)
+      a[i] = b[i];
+
+    /* Reference to a local variable not modified in the loop.  */
+    j = ((x == 4) ? (n << 2) : (n << 3));
+    for (int i = 0; i < j; i++)
+      a[i] = b[i];
+  }
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 5 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-3.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-3.c
new file mode 100644
index 0000000..f60070e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-3.c
@@ -0,0 +1,24 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a conditional in the body can be annotated.  */
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)
+      if (a[i] > 0 && b[i] > 0)
+	t += a[i] * b[i];
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-4.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-4.c
new file mode 100644
index 0000000..949871c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-4.c
@@ -0,0 +1,34 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a switch and break in the body can be annotated.  */
+
+#define n 16
+
+float f (float *a, float *b, int state)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)
+      switch (state)
+	{
+	case 0:
+	default:
+	  t += a[i] * b[i];
+	  break;
+
+	case 1:
+	  if (a[i] > 0 && b[i] > 0)
+	    t += a[i] * b[i];
+	  break;
+	}
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-5.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-5.c
new file mode 100644
index 0000000..03dfe8f
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-5.c
@@ -0,0 +1,27 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a continue statement in the body can be annotated.  */
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)
+      {
+	if (a[i] < 0 || b[i] < 0)
+	  continue;
+	t += a[i] * b[i];
+      }
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-6.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-6.c
new file mode 100644
index 0000000..ede6b3c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-6.c
@@ -0,0 +1,27 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a break statement in the body cannot be annotated.  */
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)	/* { dg-warning "loop cannot be annotated" } */
+      {
+	if (a[i] < 0 || b[i] < 0)
+	  break;
+	t += a[i] * b[i];
+      }
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-7.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-7.c
new file mode 100644
index 0000000..20ee299
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-7.c
@@ -0,0 +1,26 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with a random function call in the body cannot be
+   annotated.  */
+
+extern float g (float);
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)	/* { dg-warning "loop cannot be annotated" } */
+      t += g (a[i] * b[i]);
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 0 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-8.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-8.c
new file mode 100644
index 0000000..796f048
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-8.c
@@ -0,0 +1,27 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a loop with an openacc function call in the body can be
+   annotated.  */
+
+#pragma acc routine worker
+extern float g (float);
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)
+      t += g (a[i] * b[i]);
+  }
+  return t;
+}
+
+/* { dg-final { scan-tree-dump-times "acc loop auto" 1 "original" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-9.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-9.c
new file mode 100644
index 0000000..048f1b0
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-annotation-9.c
@@ -0,0 +1,26 @@
+/* { dg-additional-options "-fopenacc -fopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-Wopenacc-kernels-annotate-loops" } */
+/* { dg-additional-options "-fdump-tree-original" } */
+/* { dg-do compile } */
+
+/* Test that a kernels loop with a return in the body triggers a hard
+   error.  */
+
+#define n 16
+
+float f (float *a, float *b)
+{
+  float t = 0;
+  int i;
+
+#pragma acc kernels
+  {
+    for (i = 0; i < n; i++)
+      {
+	if (a[i] < 0 || b[i] < 0)
+	  return 0.0;	/* { dg-error "invalid branch" } */
+	t += a[i] * b[i];
+      }
+  }
+  return t;
+}
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-2.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-2.c
index 7180021..9a97de6 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-2.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-2.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit-2.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit-2.c
index 0c9f833..31e8378 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit-2.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit-2.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit.c
index 0bd21b6..ad59155 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-enter-exit.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-update.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-update.c
index dd5a841..4acffef 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-update.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data-update.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data.c
index a658182..327aa05 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-data.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-data.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-g.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-g.c
index 73b469d..26c65fe 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-g.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-g.c
@@ -1,5 +1,6 @@
 /* { dg-additional-options "-O2" } */
 /* { dg-additional-options "-g" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-mod-not-zero.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-mod-not-zero.c
index 5592623..8955cf2 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-mod-not-zero.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-mod-not-zero.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-n.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-n.c
index e86be1b..d88a61d 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-n.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-n.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop-nest.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop-nest.c
index 2b0e186..5943d56 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop-nest.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop-nest.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-loop.c b/gcc/testsuite/c-c++-common/goacc/kernels-loop.c
index 9619d53..ad525cd 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-loop.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-loop.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-one-counter-var.c b/gcc/testsuite/c-c++-common/goacc/kernels-one-counter-var.c
index 69539b2..f799baf 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-one-counter-var.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-one-counter-var.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-parallel-loop-data-enter-exit.c b/gcc/testsuite/c-c++-common/goacc/kernels-parallel-loop-data-enter-exit.c
index 81b0fee..b8093b5 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-parallel-loop-data-enter-exit.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-parallel-loop-data-enter-exit.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-reduction.c b/gcc/testsuite/c-c++-common/goacc/kernels-reduction.c
index 5921b88..105cbcf 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-reduction.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-reduction.c
@@ -1,4 +1,5 @@
 /* { dg-additional-options "-O2" } */
+/* { dg-additional-options "-fno-openacc-kernels-annotate-loops" } */
 /* { dg-additional-options "-fdump-tree-parloops1-all" } */
 /* { dg-additional-options "-fdump-tree-optimized" } */
 
diff --git a/gcc/tree.h b/gcc/tree.h
index 9ec24a3..9ee9124 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -1492,6 +1492,11 @@ class auto_suppress_location_wrappers
 #define OMP_TARGET_COMBINED(NODE) \
   (OMP_TARGET_CHECK (NODE)->base.private_flag)
 
+/* True on an OACC_LOOP statement if it is part of a combined construct,
+   for example "#pragma acc kernels loop".  */
+#define OACC_LOOP_COMBINED(NODE) \
+  (OACC_LOOP_CHECK (NODE)->base.private_flag)
+
 /* Memory order for OMP_ATOMIC*.  */
 #define OMP_ATOMIC_MEMORY_ORDER(NODE) \
   (TREE_RANGE_CHECK (NODE, OMP_ATOMIC, \
-- 
2.8.1



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