openmp: Add support for non-rectangular loops in taskloop construct

2020-08-13  Jakub Jelinek  <jakub@redhat.com>

	* gimplify.c (gimplify_omp_taskloop_expr): New function.
	(gimplify_omp_for): Use it.  For OMP_FOR_NON_RECTANGULAR
	loops adjust in outer taskloop the var-outer decls.
	* omp-expand.c (expand_omp_taskloop_for_inner): Handle non-rectangular
	loops.
	(expand_omp_for): Don't reject non-rectangular taskloop.
	* omp-general.c (omp_extract_for_data): Don't assert that
	non-rectangular loops have static schedule, instead treat loop->m1
	or loop->m2 as if loop->n1 or loop->n2 is non-constant.

	* testsuite/libgomp.c/loop-22.c (main): Add some further tests.
	* testsuite/libgomp.c/loop-23.c (main): Likewise.
	* testsuite/libgomp.c/loop-24.c: New test.

6 files changed, 997 insertions, 74 deletions

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 6a5349c..23d0e25 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -10996,6 +10996,37 @@ gimplify_omp_task (tree *expr_p, gimple_seq *pre_p)
   *expr_p = NULL_TREE;
 }
 
+/* Helper function for gimplify_omp_for.  If *TP is not a gimple constant,
+   force it into a temporary initialized in PRE_P and add firstprivate clause
+   to ORIG_FOR_STMT.  */
+
+static void
+gimplify_omp_taskloop_expr (tree type, tree *tp, gimple_seq *pre_p,
+			    tree orig_for_stmt)
+{
+  if (*tp == NULL || is_gimple_constant (*tp))
+    return;
+
+  *tp = get_initialized_tmp_var (*tp, pre_p, NULL, false);
+  /* Reference to pointer conversion is considered useless,
+     but is significant for firstprivate clause.  Force it
+     here.  */
+  if (type
+      && TREE_CODE (type) == POINTER_TYPE
+      && TREE_CODE (TREE_TYPE (*tp)) == REFERENCE_TYPE)
+    {
+      tree v = create_tmp_var (TYPE_MAIN_VARIANT (type));
+      tree m = build2 (INIT_EXPR, TREE_TYPE (v), v, *tp);
+      gimplify_and_add (m, pre_p);
+      *tp = v;
+    }
+
+  tree c = build_omp_clause (input_location, OMP_CLAUSE_FIRSTPRIVATE);
+  OMP_CLAUSE_DECL (c) = *tp;
+  OMP_CLAUSE_CHAIN (c) = OMP_FOR_CLAUSES (orig_for_stmt);
+  OMP_FOR_CLAUSES (orig_for_stmt) = c;
+}
+
 /* Gimplify the gross structure of an OMP_FOR statement.  */
 
 static enum gimplify_status
@@ -11298,65 +11329,34 @@ gimplify_omp_for (tree *expr_p, gimple_seq *pre_p)
       for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt)); i++)
 	{
 	  t = TREE_VEC_ELT (OMP_FOR_INIT (for_stmt), i);
-	  if (!is_gimple_constant (TREE_OPERAND (t, 1)))
-	    {
+	  gimple_seq *for_pre_p = (gimple_seq_empty_p (for_pre_body)
+				   ? pre_p : &for_pre_body);
 	      tree type = TREE_TYPE (TREE_OPERAND (t, 0));
-	      TREE_OPERAND (t, 1)
-		= get_initialized_tmp_var (TREE_OPERAND (t, 1),
-					   gimple_seq_empty_p (for_pre_body)
-					   ? pre_p : &for_pre_body, NULL,
-					   false);
-	      /* Reference to pointer conversion is considered useless,
-		 but is significant for firstprivate clause.  Force it
-		 here.  */
-	      if (TREE_CODE (type) == POINTER_TYPE
-		  && (TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 1)))
-		      == REFERENCE_TYPE))
-		{
-		  tree v = create_tmp_var (TYPE_MAIN_VARIANT (type));
-		  tree m = build2 (INIT_EXPR, TREE_TYPE (v), v,
-				   TREE_OPERAND (t, 1));
-		  gimplify_and_add (m, gimple_seq_empty_p (for_pre_body)
-				       ? pre_p : &for_pre_body);
-		  TREE_OPERAND (t, 1) = v;
-		}
-	      tree c = build_omp_clause (input_location,
-					 OMP_CLAUSE_FIRSTPRIVATE);
-	      OMP_CLAUSE_DECL (c) = TREE_OPERAND (t, 1);
-	      OMP_CLAUSE_CHAIN (c) = OMP_FOR_CLAUSES (orig_for_stmt);
-	      OMP_FOR_CLAUSES (orig_for_stmt) = c;
+	  if (TREE_CODE (TREE_OPERAND (t, 1)) == TREE_VEC)
+	    {
+	      tree v = TREE_OPERAND (t, 1);
+	      gimplify_omp_taskloop_expr (type, &TREE_VEC_ELT (v, 1),
+					  for_pre_p, orig_for_stmt);
+	      gimplify_omp_taskloop_expr (type, &TREE_VEC_ELT (v, 2),
+					  for_pre_p, orig_for_stmt);
 	    }
+	  else
+	    gimplify_omp_taskloop_expr (type, &TREE_OPERAND (t, 1), for_pre_p,
+					orig_for_stmt);
 
 	  /* Handle OMP_FOR_COND.  */
 	  t = TREE_VEC_ELT (OMP_FOR_COND (for_stmt), i);
-	  if (!is_gimple_constant (TREE_OPERAND (t, 1)))
+	  if (TREE_CODE (TREE_OPERAND (t, 1)) == TREE_VEC)
 	    {
-	      tree type = TREE_TYPE (TREE_OPERAND (t, 0));
-	      TREE_OPERAND (t, 1)
-		= get_initialized_tmp_var (TREE_OPERAND (t, 1),
-					   gimple_seq_empty_p (for_pre_body)
-					   ? pre_p : &for_pre_body, NULL,
-					   false);
-	      /* Reference to pointer conversion is considered useless,
-		 but is significant for firstprivate clause.  Force it
-		 here.  */
-	      if (TREE_CODE (type) == POINTER_TYPE
-		  && (TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 1)))
-		      == REFERENCE_TYPE))
-		{
-		  tree v = create_tmp_var (TYPE_MAIN_VARIANT (type));
-		  tree m = build2 (INIT_EXPR, TREE_TYPE (v), v,
-				   TREE_OPERAND (t, 1));
-		  gimplify_and_add (m, gimple_seq_empty_p (for_pre_body)
-				       ? pre_p : &for_pre_body);
-		  TREE_OPERAND (t, 1) = v;
-		}
-	      tree c = build_omp_clause (input_location,
-					 OMP_CLAUSE_FIRSTPRIVATE);
-	      OMP_CLAUSE_DECL (c) = TREE_OPERAND (t, 1);
-	      OMP_CLAUSE_CHAIN (c) = OMP_FOR_CLAUSES (orig_for_stmt);
-	      OMP_FOR_CLAUSES (orig_for_stmt) = c;
+	      tree v = TREE_OPERAND (t, 1);
+	      gimplify_omp_taskloop_expr (type, &TREE_VEC_ELT (v, 1),
+					  for_pre_p, orig_for_stmt);
+	      gimplify_omp_taskloop_expr (type, &TREE_VEC_ELT (v, 2),
+					  for_pre_p, orig_for_stmt);
 	    }
+	  else
+	    gimplify_omp_taskloop_expr (type, &TREE_OPERAND (t, 1), for_pre_p,
+					orig_for_stmt);
 
 	  /* Handle OMP_FOR_INCR.  */
 	  t = TREE_VEC_ELT (OMP_FOR_INCR (for_stmt), i);
@@ -11368,17 +11368,8 @@ gimplify_omp_for (tree *expr_p, gimple_seq *pre_p)
 	      if (TREE_CODE (t) == PLUS_EXPR && *tp == decl)
 		tp = &TREE_OPERAND (t, 0);
 
-	      if (!is_gimple_constant (*tp))
-		{
-		  gimple_seq *seq = gimple_seq_empty_p (for_pre_body)
-				    ? pre_p : &for_pre_body;
-		  *tp = get_initialized_tmp_var (*tp, seq, NULL, false);
-		  tree c = build_omp_clause (input_location,
-					     OMP_CLAUSE_FIRSTPRIVATE);
-		  OMP_CLAUSE_DECL (c) = *tp;
-		  OMP_CLAUSE_CHAIN (c) = OMP_FOR_CLAUSES (orig_for_stmt);
-		  OMP_FOR_CLAUSES (orig_for_stmt) = c;
-		}
+	      gimplify_omp_taskloop_expr (NULL_TREE, tp, for_pre_p,
+					  orig_for_stmt);
 	    }
 	}
 
@@ -12220,6 +12211,34 @@ gimplify_omp_for (tree *expr_p, gimple_seq *pre_p)
 	  OMP_CLAUSE_DECL (t) = v;
 	  OMP_CLAUSE_CHAIN (t) = gimple_omp_for_clauses (gforo);
 	  gimple_omp_for_set_clauses (gforo, t);
+	  if (OMP_FOR_NON_RECTANGULAR (for_stmt))
+	    {
+	      tree *p1 = NULL, *p2 = NULL;
+	      t = gimple_omp_for_initial (gforo, i);
+	      if (TREE_CODE (t) == TREE_VEC)
+		p1 = &TREE_VEC_ELT (t, 0);
+	      t = gimple_omp_for_final (gforo, i);
+	      if (TREE_CODE (t) == TREE_VEC)
+		{
+		  if (p1)
+		    p2 = &TREE_VEC_ELT (t, 0);
+		  else
+		    p1 = &TREE_VEC_ELT (t, 0);
+		}
+	      if (p1)
+		{
+		  int j;
+		  for (j = 0; j < i; j++)
+		    if (*p1 == gimple_omp_for_index (gfor, j))
+		      {
+			*p1 = gimple_omp_for_index (gforo, j);
+			if (p2)
+			  *p2 = *p1;
+			break;
+		      }
+		  gcc_assert (j < i);
+		}
+	    }
 	}
       gimplify_seq_add_stmt (pre_p, gforo);
     }
diff --git a/gcc/omp-expand.c b/gcc/omp-expand.c
index eb37b38..8f1286e 100644
--- a/gcc/omp-expand.c
+++ b/gcc/omp-expand.c
@@ -6917,8 +6917,20 @@ expand_omp_taskloop_for_inner (struct omp_region *region,
 	assign_stmt = gimple_build_assign (fd->loop.v, NOP_EXPR, e);
       gsi_insert_after (&gsi, assign_stmt, GSI_CONTINUE_LINKING);
     }
+
+  tree *nonrect_bounds = NULL;
   if (fd->collapse > 1)
-    expand_omp_for_init_vars (fd, &gsi, counts, NULL, inner_stmt, startvar);
+    {
+      if (fd->non_rect)
+	{
+	  nonrect_bounds = XALLOCAVEC (tree, fd->last_nonrect + 1);
+	  memset (nonrect_bounds, 0, sizeof (tree) * (fd->last_nonrect + 1));
+	}
+      gcc_assert (gsi_bb (gsi) == entry_bb);
+      expand_omp_for_init_vars (fd, &gsi, counts, nonrect_bounds, inner_stmt,
+				startvar);
+      entry_bb = gsi_bb (gsi);
+    }
 
   if (!broken_loop)
     {
@@ -6953,7 +6965,8 @@ expand_omp_taskloop_for_inner (struct omp_region *region,
       gsi_remove (&gsi, true);
 
       if (fd->collapse > 1 && !gimple_omp_for_combined_p (fd->for_stmt))
-	collapse_bb = extract_omp_for_update_vars (fd, NULL, cont_bb, body_bb);
+	collapse_bb = extract_omp_for_update_vars (fd, nonrect_bounds,
+						   cont_bb, body_bb);
     }
 
   /* Remove the GIMPLE_OMP_FOR statement.  */
@@ -7643,9 +7656,6 @@ expand_omp_for (struct omp_region *region, gimple *inner_stmt)
     }
   else if (gimple_omp_for_kind (fd.for_stmt) == GF_OMP_FOR_KIND_TASKLOOP)
     {
-      if (fd.non_rect)
-	sorry_at (gimple_location (fd.for_stmt),
-		  "non-rectangular %<taskloop%> not supported yet");
       if (gimple_omp_for_combined_into_p (fd.for_stmt))
 	expand_omp_taskloop_for_inner (region, &fd, inner_stmt);
       else
diff --git a/gcc/omp-general.c b/gcc/omp-general.c
index 6e6d3e1..8e2665a 100644
--- a/gcc/omp-general.c
+++ b/gcc/omp-general.c
@@ -444,10 +444,6 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd,
 	      = build_nonstandard_integer_type
 		  (TYPE_PRECISION (TREE_TYPE (loop->v)), 1);
 	}
-      else if (loop->m1 || loop->m2)
-	/* Non-rectangular loops should use static schedule and no
-	   ordered clause.  */
-	gcc_unreachable ();
       else if (iter_type != long_long_unsigned_type_node)
 	{
 	  if (POINTER_TYPE_P (TREE_TYPE (loop->v)))
@@ -463,7 +459,9 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd,
 				     loop->n2, loop->step);
 	      else
 		n = loop->n1;
-	      if (TREE_CODE (n) != INTEGER_CST
+	      if (loop->m1
+		  || loop->m2
+		  || TREE_CODE (n) != INTEGER_CST
 		  || tree_int_cst_lt (TYPE_MAX_VALUE (iter_type), n))
 		iter_type = long_long_unsigned_type_node;
 	    }
@@ -484,7 +482,9 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd,
 					loop->n2, loop->step);
 		  n2 = loop->n1;
 		}
-	      if (TREE_CODE (n1) != INTEGER_CST
+	      if (loop->m1
+		  || loop->m2
+		  || TREE_CODE (n1) != INTEGER_CST
 		  || TREE_CODE (n2) != INTEGER_CST
 		  || !tree_int_cst_lt (TYPE_MIN_VALUE (iter_type), n1)
 		  || !tree_int_cst_lt (n2, TYPE_MAX_VALUE (iter_type)))
diff --git a/libgomp/testsuite/libgomp.c/loop-22.c b/libgomp/testsuite/libgomp.c/loop-22.c
index b07efee..431e43b 100644
--- a/libgomp/testsuite/libgomp.c/loop-22.c
+++ b/libgomp/testsuite/libgomp.c/loop-22.c
@@ -185,5 +185,240 @@ main ()
   for (int n = l; n < 2 * l; n++)
     if (v[0][j][0][l][0][n][0] != 7)
       abort ();
+
+  {
+  static int i, j, x;
+  static volatile int a, b, c, d, e, f, g, h;
+  static int w[13][27];
+  for (i = -4; i < 8; i++)
+    for (j = 3 * i; j > 2 * i; j--)
+      w[i + 5][j + 5] = 1;
+  a = -4; b = 8; c = 1; d = 3; e = 0; f = 2; g = 0; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = -4; i < 8; i++)
+    for (j = 3 * i; j > 2 * i; j--)
+      {
+	if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != 8 || j != 14 || x != 7183 || niters != 28)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = a; i < b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != 8 || j != 14 || x != 7183 || niters != 28)
+    abort ();
+  for (int i = -4; i < 8; i++)
+    for (int j = 3 * i; j > 2 * i; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      w[i + 5][j + 5] = 1;
+  a = -2; b = 4; c = 1; d = -2; e = 3; f = 0; g = -3; h = -2;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      {
+	if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/* i != 4 || j != -3 || */x != 3071 || niters != 15)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = a; i < b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != 4 || j != -3 || */x != 3071 || niters != 15)
+    abort ();
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      w[i + 5][j + 5] = 1;
+  a = 3; b = -3; c = -1; d = -2; e = 7; f = 2; g = 1; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      {
+	if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -3 || j != -3 || x != -1026 || niters != 32)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -3 || j != -3 || x != -1026 || niters != 32)
+    abort ();
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      w[i + 5][j + 5] = 1;
+  a = 3; b = -3; c = -1; d = 2; e = 7; f = -2; g = 1; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      {
+	if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -3 || j != 3 || */x != -1020 || niters != 50)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -3 || j != 3 || */x != -1020 || niters != 50)
+    abort ();
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      w[i + 5][j + 5] = 1;
+  a = 6; b = -6; c = -1; d = 2; e = 7; f = -2; g = 2; h = 1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      {
+	if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -6 || j != 12 || x != -5109 || niters != 36)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j < g + i * f; j += h)
+      {
+	if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -6 || j != 12 || x != -5109 || niters != 36)
+    abort ();
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      w[i + 5][j + 5] = 1;
+  a = 6; b = -6; c = -2; d = -2; e = 7; f = 2; g = 2; h = 1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      {
+	if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -6 || j != 15 || */x != 2053 || niters != 33)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute collapse(2) lastprivate (i, j, x)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j < g + i * f; j += h)
+      {
+	if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -6 || j != 15 || */x != 2053 || niters != 33)
+    abort ();
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  }
+
   return 0;
 }
diff --git a/libgomp/testsuite/libgomp.c/loop-23.c b/libgomp/testsuite/libgomp.c/loop-23.c
index 30bb82c..1476db2 100644
--- a/libgomp/testsuite/libgomp.c/loop-23.c
+++ b/libgomp/testsuite/libgomp.c/loop-23.c
@@ -185,5 +185,240 @@ main ()
   for (int n = l; n < 2 * l; n++)
     if (v[0][j][0][l][0][n][0] != 7)
       abort ();
+
+  {
+  static int i, j, x;
+  static volatile int a, b, c, d, e, f, g, h;
+  static int w[13][27];
+  for (i = -4; i < 8; i++)
+    for (j = 3 * i; j > 2 * i; j--)
+      w[i + 5][j + 5] = 1;
+  a = -4; b = 8; c = 1; d = 3; e = 0; f = 2; g = 0; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = -4; i < 8; i++)
+    for (j = 3 * i; j > 2 * i; j--)
+      {
+	if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != 8 || j != 14 || x != 7183 || niters != 28)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = a; i < b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != 8 || j != 14 || x != 7183 || niters != 28)
+    abort ();
+  for (int i = -4; i < 8; i++)
+    for (int j = 3 * i; j > 2 * i; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      w[i + 5][j + 5] = 1;
+  a = -2; b = 4; c = 1; d = -2; e = 3; f = 0; g = -3; h = -2;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      {
+	if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/* i != 4 || j != -3 || */x != 3071 || niters != 15)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = a; i < b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != 4 || j != -3 || */x != 3071 || niters != 15)
+    abort ();
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      w[i + 5][j + 5] = 1;
+  a = 3; b = -3; c = -1; d = -2; e = 7; f = 2; g = 1; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      {
+	if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -3 || j != -3 || x != -1026 || niters != 32)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -3 || j != -3 || x != -1026 || niters != 32)
+    abort ();
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      w[i + 5][j + 5] = 1;
+  a = 3; b = -3; c = -1; d = 2; e = 7; f = -2; g = 1; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      {
+	if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -3 || j != 3 || */x != -1020 || niters != 50)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -3 || j != 3 || */x != -1020 || niters != 50)
+    abort ();
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      w[i + 5][j + 5] = 1;
+  a = 6; b = -6; c = -1; d = 2; e = 7; f = -2; g = 2; h = 1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      {
+	if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -6 || j != 12 || x != -5109 || niters != 36)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j < g + i * f; j += h)
+      {
+	if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -6 || j != 12 || x != -5109 || niters != 36)
+    abort ();
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      w[i + 5][j + 5] = 1;
+  a = 6; b = -6; c = -2; d = -2; e = 7; f = 2; g = 2; h = 1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      {
+	if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -6 || j != 15 || */x != 2053 || niters != 33)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp teams reduction(+:niters)
+  #pragma omp distribute parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j < g + i * f; j += h)
+      {
+	if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -6 || j != 15 || */x != 2053 || niters != 33)
+    abort ();
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  }
+
   return 0;
 }
diff --git a/libgomp/testsuite/libgomp.c/loop-24.c b/libgomp/testsuite/libgomp.c/loop-24.c
new file mode 100644
index 0000000..24aa01e
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c/loop-24.c
@@ -0,0 +1,424 @@
+/* { dg-do run } */
+
+extern void abort (void);
+
+signed char v[5][7][9][21][4][42][3];
+volatile int zero = 0, one = 1, two = 2, three = 3;
+volatile int five = 5, seven = 7, nine = 9, eleven = 11;
+
+int
+main ()
+{
+  for (int i = 0; i < 5; i++)
+  for (int j = 0; j < 7; j++)
+  for (int k = 0; k < 9; k++)
+  for (int l = 2 * j; l < 3 * j; l++)
+  for (int m = 7; m < 11; m++)
+  for (int n = l; n < 2 * l; n++)
+  for (int o = 0; o < 3; o++)
+    v[i][j][k][l][m - 7][n][o] = 1;
+
+  int niters = 0;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(7) in_reduction(+:niters)
+  for (int i = 0; i < 5; i++)
+  for (int j = 0; j < 7; j++)
+  for (int k = 0; k < 9; k++)
+  for (int l = 2 * j; l < 3 * j; l++)
+  for (int m = 7; m < 11; m++)
+  for (int n = l; n < 2 * l; n++)
+  for (int o = 0; o < 3; o++)
+    {
+      niters++;
+      if (i < 0 || i >= 5
+	  || j < 0 || j >= 7
+	  || k < 0 || k >= 9
+	  || l < 2 * j || l >= 3 * j
+	  || m < 7 || m >= 11
+	  || n < l || n >= 2 * l
+	  || o < 0 || o >= 3)
+	abort ();
+      if (v[i][j][k][l][m - 7][n][o] != 1)
+	abort ();
+      v[i][j][k][l][m - 7][n][o]++;
+    }
+
+  if (niters != 117180)
+    abort ();
+
+  int niters2 = 0;
+  #pragma omp parallel master reduction(task, +:niters2)
+  #pragma omp taskloop collapse(7) in_reduction(+:niters2)
+  for (int i = zero; i < five; i += one)
+  for (int j = seven - one; j >= zero; j -= one)
+  for (int k = nine - one; k >= zero; k += -one)
+  for (int l = two * j + zero; l < three * j; l += one)
+  for (int m = eleven - one; m >= seven; m -= one)
+  for (int n = two * l - one; n > one * l - one; n -= one)
+  for (int o = zero; o < three; o += one)
+    {
+      niters2++;
+      if (i < 0 || i >= 5
+	  || j < 0 || j >= 7
+	  || k < 0 || k >= 9
+	  || l < 2 * j || l >= 3 * j
+	  || m < 7 || m >= 11
+	  || n < l || n >= 2 * l
+	  || o < 0 || o >= 3)
+	abort ();
+      if (v[i][j][k][l][m - 7][n][o] != 2)
+	abort ();
+      v[i][j][k][l][m - 7][n][o]++;
+    }
+
+  if (niters2 != 117180)
+    abort ();
+
+  for (int i = 0; i < 5; i++)
+  for (int j = 0; j < 7; j++)
+  for (int k = 0; k < 9; k++)
+  for (int l = 2 * j; l < 3 * j; l++)
+  for (int m = 7; m < 11; m++)
+  for (int n = l; n < 2 * l; n++)
+  for (int o = 0; o < 3; o++)
+    if (v[i][j][k][l][m - 7][n][o] != 3)
+      abort ();
+
+  int niters3 = 0;
+  #pragma omp parallel master reduction(task, +:niters3)
+  #pragma omp taskloop collapse(5) in_reduction(+:niters3)
+  for (int i = 4; i >= 0; i--)
+  for (int j = 6; j >= 0; --j)
+  for (int l = 3 * j - 1; l >= 2 * j; l--)
+  for (int n = 2 * l + -1; n > l - 1; --n)
+  for (int o = 2; o >= 0; o--)
+    {
+      niters3++;
+      if (i < 0 || i >= 5
+	  || j < 0 || j >= 7
+	  || l < 2 * j || l >= 3 * j
+	  || n < l || n >= 2 * l
+	  || o < 0 || o >= 3)
+	abort ();
+      if (v[i][j][0][l][0][n][o] != 3)
+	abort ();
+      v[i][j][0][l][0][n][o]++;
+    }
+
+  if (niters3 != 3255)
+    abort ();
+
+  int niters4 = 0;
+  #pragma omp parallel master reduction(task, +:niters4)
+  #pragma omp taskloop collapse(5) in_reduction(+:niters4)
+  for (int i = zero; i < five; i += one)
+  for (int j = zero; j <= seven - one; j += one)
+  for (int l = j * two; l < three * j + zero; l += one)
+  for (int n = one * l; n <= l * two - one; n += one)
+  for (int o = zero; o < three; o += one)
+    {
+      niters4++;
+      if (i < 0 || i >= 5
+	  || j < 0 || j >= 7
+	  || l < 2 * j || l >= 3 * j
+	  || n < l || n >= 2 * l
+	  || o < 0 || o >= 3)
+	abort ();
+      if (v[i][j][0][l][0][n][o] != 4)
+	abort ();
+      v[i][j][0][l][0][n][o]++;
+    }
+
+  if (niters4 != 3255)
+    abort ();
+
+  for (int i = 0; i < 5; i++)
+  for (int j = 0; j < 7; j++)
+  for (int l = 2 * j; l < 3 * j; l++)
+  for (int n = l; n < 2 * l; n++)
+  for (int o = 0; o < 3; o++)
+    if (v[i][j][0][l][0][n][o] != 5)
+      abort ();
+
+  int niters5 = 0;
+  #pragma omp parallel master reduction(task, +:niters5)
+  #pragma omp taskloop collapse(3) in_reduction(+:niters5)
+  for (int j = 6; j >= 0; --j)
+  for (int l = 2 * j; l <= 3 * j - 1; l++)
+  for (int n = 2 * l + -1; n > l - 1; --n)
+    {
+      niters5++;
+      if (j < 0 || j >= 7
+	  || l < 2 * j || l >= 3 * j
+	  || n < l || n >= 2 * l)
+	abort ();
+      if (v[0][j][0][l][0][n][0] != 5)
+	abort ();
+      v[0][j][0][l][0][n][0]++;
+    }
+
+  if (niters5 != 217)
+    abort ();
+
+  int niters6 = 0;
+  #pragma omp parallel master reduction(task, +:niters6)
+  #pragma omp taskloop collapse(3) in_reduction(+:niters6)
+  for (int j = seven - one; j > - one; j -= one)
+  for (int l = j * three - one; l >= j * two + zero; l += -one)
+  for (int n = two * l - one; n > l - one; n -= one)
+    {
+      niters6++;
+      if (j < 0 || j >= 7
+	  || l < 2 * j || l >= 3 * j
+	  || n < l || n >= 2 * l)
+	abort ();
+      if (v[0][j][0][l][0][n][0] != 6)
+	abort ();
+      v[0][j][0][l][0][n][0]++;
+    }
+
+  if (niters6 != 217)
+    abort ();
+
+  for (int j = 0; j < 7; j++)
+  for (int l = 2 * j; l < 3 * j; l++)
+  for (int n = l; n < 2 * l; n++)
+    if (v[0][j][0][l][0][n][0] != 7)
+      abort ();
+
+  {
+  static int i, j, x;
+  static volatile int a, b, c, d, e, f, g, h;
+  static int w[13][27];
+  for (i = -4; i < 8; i++)
+    for (j = 3 * i; j > 2 * i; j--)
+      w[i + 5][j + 5] = 1;
+  a = -4; b = 8; c = 1; d = 3; e = 0; f = 2; g = 0; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = -4; i < 8; i++)
+    for (j = 3 * i; j > 2 * i; j--)
+      {
+	if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != 8 || j != 14 || x != 7183 || niters != 28)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = a; i < b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != 8 || j != 14 || x != 7183 || niters != 28)
+    abort ();
+  for (int i = -4; i < 8; i++)
+    for (int j = 3 * i; j > 2 * i; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      w[i + 5][j + 5] = 1;
+  a = -2; b = 4; c = 1; d = -2; e = 3; f = 0; g = -3; h = -2;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      {
+	if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/* i != 4 || j != -3 || */x != 3071 || niters != 15)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = a; i < b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != 4 || j != -3 || */x != 3071 || niters != 15)
+    abort ();
+  for (i = -2; i < 4; i++)
+    for (j = -2 * i + 3; j > -3; j -= 2)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      w[i + 5][j + 5] = 1;
+  a = 3; b = -3; c = -1; d = -2; e = 7; f = 2; g = 1; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      {
+	if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -3 || j != -3 || x != -1026 || niters != 32)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -3 || j != -3 || x != -1026 || niters != 32)
+    abort ();
+  for (i = 3; i > -3; i--)
+    for (j = -2 * i + 7; j > 2 * i + 1; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      w[i + 5][j + 5] = 1;
+  a = 3; b = -3; c = -1; d = 2; e = 7; f = -2; g = 1; h = -1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      {
+	if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -3 || j != 3 || */x != -1020 || niters != 50)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j > g + i * f; j += h)
+      {
+	if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -3 || j != 3 || */x != -1020 || niters != 50)
+    abort ();
+  for (i = 3; i > -3; i--)
+    for (j = 2 * i + 7; j > -2 * i + 1; j--)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      w[i + 5][j + 5] = 1;
+  a = 6; b = -6; c = -1; d = 2; e = 7; f = -2; g = 2; h = 1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      {
+	if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -6 || j != 12 || x != -5109 || niters != 36)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j < g + i * f; j += h)
+      {
+	if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (i != -6 || j != 12 || x != -5109 || niters != 36)
+    abort ();
+  for (i = 6; i > -6; i--)
+    for (j = 2 * i + 7; j <= -2 * i + 1; j++)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      w[i + 5][j + 5] = 1;
+  a = 6; b = -6; c = -2; d = -2; e = 7; f = 2; g = 2; h = 1;
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      {
+	if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || w[i + 5][j + 5] != 1)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -6 || j != 15 || */x != 2053 || niters != 33)
+    abort ();
+  niters = 0; i = -100; j = -100; x = -100;
+  #pragma omp parallel master reduction(task, +:niters)
+  #pragma omp taskloop collapse(2) lastprivate (i, j, x) in_reduction(+:niters)
+  for (i = a; i > b; i += c)
+    for (j = d * i + e; j < g + i * f; j += h)
+      {
+	if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || w[i + 5][j + 5] != 2)
+	  abort ();
+	w[i + 5][j + 5]++;
+	x = i * 1024 + (j & 1023);
+	niters++;
+      }
+  if (/*i != -6 || j != 15 || */x != 2053 || niters != 33)
+    abort ();
+  for (i = 6; i > -6; i -= 2)
+    for (j = -2 * i + 7; j <= 2 * i + 1; j++)
+      if (w[i + 5][j + 5] == 3)
+	w[i + 5][j + 5] = 0;
+      else
+	abort ();
+  }
+
+  return 0;
+}