New Graphite files.

2009-07-30  Sebastian Pop  <sebastian.pop@amd.com>

	* ChangeLog.graphite: New.
	* graphite-blocking.c: New.
	* graphite-clast-to-gimple.c: New.
	* graphite-clast-to-gimple.h: New.
	* graphite-dependences.c: New.
	* graphite-dependences.h: New.
	* graphite-interchange.c: New.
	* graphite-poly.c: New.
	* graphite-poly.h: New.
	* graphite-ppl.c: New.
	* graphite-ppl.h: New.
	* graphite-scop-detection.c: New.
	* graphite-scop-detection.h: New.
	* graphite-sese-to-poly.c: New.
	* graphite-sese-to-poly.h: New.
	* sese.c: New.
	* sese.h: New.

From-SVN: r150300

1 files changed, 752 insertions, 0 deletions

diff --git a/gcc/graphite-poly.c b/gcc/graphite-poly.c
new file mode 100644
index 00000000000..da2beb3c4d7
--- /dev/null
+++ b/gcc/graphite-poly.c
@@ -0,0 +1,752 @@
+/* Graphite polyhedral representation.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+   Contributed by Sebastian Pop <sebastian.pop@amd.com> and
+   Tobias Grosser <grosser@fim.uni-passau.de>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "ggc.h"
+#include "tree.h"
+#include "rtl.h"
+#include "output.h"
+#include "basic-block.h"
+#include "diagnostic.h"
+#include "tree-flow.h"
+#include "toplev.h"
+#include "tree-dump.h"
+#include "timevar.h"
+#include "cfgloop.h"
+#include "tree-chrec.h"
+#include "tree-data-ref.h"
+#include "tree-scalar-evolution.h"
+#include "tree-pass.h"
+#include "domwalk.h"
+#include "value-prof.h"
+#include "pointer-set.h"
+#include "gimple.h"
+#include "params.h"
+
+#ifdef HAVE_cloog
+#include "cloog/cloog.h"
+#include "ppl_c.h"
+#include "sese.h"
+#include "graphite-ppl.h"
+#include "graphite.h"
+#include "graphite-poly.h"
+#include "graphite-dependences.h"
+
+/* Return the maximal loop depth in SCOP.  */
+
+int
+scop_max_loop_depth (scop_p scop)
+{
+  int i;
+  poly_bb_p pbb;
+  int max_nb_loops = 0;
+
+  for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
+    {
+      int nb_loops = pbb_dim_iter_domain (pbb);
+      if (max_nb_loops < nb_loops)
+        max_nb_loops = nb_loops;
+    }
+
+  return max_nb_loops;
+}
+
+/* Extend the scattering matrix of PBB to MAX_SCATTERING scattering
+   dimensions.  */
+
+static void
+extend_scattering (poly_bb_p pbb, int max_scattering)
+{
+  ppl_dimension_type nb_old_dims, nb_new_dims;
+  int nb_added_dims, i;
+  ppl_Coefficient_t coef;
+  Value one;
+
+  nb_added_dims = max_scattering - pbb_nb_scattering_transform (pbb);
+  value_init (one);
+  value_set_si (one, 1);
+  ppl_new_Coefficient (&coef);
+  ppl_assign_Coefficient_from_mpz_t (coef, one);
+
+  gcc_assert (nb_added_dims >= 0);
+
+  nb_old_dims = pbb_nb_scattering_transform (pbb) + pbb_dim_iter_domain (pbb)
+    + scop_nb_params (PBB_SCOP (pbb));
+  nb_new_dims = nb_old_dims + nb_added_dims;
+
+  ppl_insert_dimensions (PBB_TRANSFORMED_SCATTERING (pbb),
+			 pbb_nb_scattering_transform (pbb), nb_added_dims);
+  PBB_NB_SCATTERING_TRANSFORM (pbb) += nb_added_dims;
+
+  /* Add identity matrix for the added dimensions.  */
+  for (i = max_scattering - nb_added_dims; i < max_scattering; i++)
+    {
+      ppl_Constraint_t cstr;
+      ppl_Linear_Expression_t expr;
+
+      ppl_new_Linear_Expression_with_dimension (&expr, nb_new_dims);
+      ppl_Linear_Expression_add_to_coefficient (expr, i, coef);
+      ppl_new_Constraint (&cstr, expr, PPL_CONSTRAINT_TYPE_EQUAL);
+      ppl_Polyhedron_add_constraint (PBB_TRANSFORMED_SCATTERING (pbb), cstr);
+      ppl_delete_Constraint (cstr);
+      ppl_delete_Linear_Expression (expr);
+    }
+
+  ppl_delete_Coefficient (coef);
+  value_clear (one);
+}
+
+/* All scattering matrices in SCOP will have the same number of scattering
+   dimensions.  */
+
+int
+unify_scattering_dimensions (scop_p scop)
+{
+  int i;
+  poly_bb_p pbb;
+  graphite_dim_t max_scattering = 0;
+
+  for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
+    max_scattering = MAX (pbb_nb_scattering_transform (pbb), max_scattering);
+
+  for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
+    extend_scattering (pbb, max_scattering);
+
+  return max_scattering;
+}
+
+/* Prints to FILE the scattering function of PBB.  */
+
+void
+print_scattering_function (FILE *file, poly_bb_p pbb)
+{
+  graphite_dim_t i;
+
+  if (!PBB_TRANSFORMED_SCATTERING (pbb))
+    return;
+
+  fprintf (file, "scattering bb_%d (\n", GBB_BB (PBB_BLACK_BOX (pbb))->index);
+  fprintf (file, "#  eq");
+
+  for (i = 0; i < pbb_nb_scattering_transform (pbb); i++)
+    fprintf (file, "     s%d", (int) i);
+
+  for (i = 0; i < pbb_nb_local_vars (pbb); i++)
+    fprintf (file, "    lv%d", (int) i);
+
+  for (i = 0; i < pbb_dim_iter_domain (pbb); i++)
+    fprintf (file, "     i%d", (int) i);
+
+  for (i = 0; i < pbb_nb_params (pbb); i++)
+    fprintf (file, "     p%d", (int) i);
+
+  fprintf (file, "    cst\n");
+
+  ppl_print_polyhedron_matrix (file, PBB_TRANSFORMED_SCATTERING (pbb));
+
+  fprintf (file, ")\n");
+}
+
+/* Prints to FILE the iteration domain of PBB.  */
+
+void
+print_iteration_domain (FILE *file, poly_bb_p pbb)
+{
+  print_pbb_domain (file, pbb);
+}
+
+/* Prints to FILE the scattering functions of every PBB of SCOP.  */
+
+void
+print_scattering_functions (FILE *file, scop_p scop)
+{
+  int i;
+  poly_bb_p pbb;
+
+  for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
+    print_scattering_function (file, pbb);
+}
+
+/* Prints to FILE the iteration domains of every PBB of SCOP.  */
+
+void
+print_iteration_domains (FILE *file, scop_p scop)
+{
+  int i;
+  poly_bb_p pbb;
+
+  for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
+    print_iteration_domain (file, pbb);
+}
+
+/* Prints to STDERR the scattering function of PBB.  */
+
+void
+debug_scattering_function (poly_bb_p pbb)
+{
+  print_scattering_function (stderr, pbb);
+}
+
+/* Prints to STDERR the iteration domain of PBB.  */
+
+void
+debug_iteration_domain (poly_bb_p pbb)
+{
+  print_iteration_domain (stderr, pbb);
+}
+
+/* Prints to STDERR the scattering functions of every PBB of SCOP.  */
+
+void
+debug_scattering_functions (scop_p scop)
+{
+  print_scattering_functions (stderr, scop);
+}
+
+/* Prints to STDERR the iteration domains of every PBB of SCOP.  */
+
+void
+debug_iteration_domains (scop_p scop)
+{
+  print_iteration_domains (stderr, scop);
+}
+
+/* Apply graphite transformations to all the basic blocks of SCOP.  */
+
+bool
+apply_poly_transforms (scop_p scop)
+{
+  bool transform_done = false;
+
+  gcc_assert (graphite_legal_transform (scop));
+
+  /* Generate code even if we did not apply any real transformation.
+     This also allows to check the performance for the identity
+     transformation: GIMPLE -> GRAPHITE -> GIMPLE
+     Keep in mind that CLooG optimizes in control, so the loop structure
+     may change, even if we only use -fgraphite-identity.  */
+  if (flag_graphite_identity)
+    transform_done = true;
+
+  if (flag_graphite_force_parallel)
+    transform_done = true;
+
+  if (flag_loop_block)
+    gcc_unreachable (); /* Not yet supported.  */
+
+  if (flag_loop_strip_mine)
+    {
+      transform_done |= scop_do_strip_mine (scop);
+      gcc_assert (graphite_legal_transform (scop));
+    }
+
+  if (flag_loop_interchange)
+    {
+      transform_done |= scop_do_interchange (scop);
+      gcc_assert (graphite_legal_transform (scop));
+    }
+
+  return transform_done;
+}
+
+/* Create a new polyhedral data reference and add it to PBB. It is defined by
+   its ACCESSES, its TYPE*/
+
+void
+new_poly_dr (poly_bb_p pbb,
+	     ppl_Pointset_Powerset_C_Polyhedron_t accesses,
+	     ppl_Pointset_Powerset_C_Polyhedron_t data_container,
+	     enum POLY_DR_TYPE type, void *cdr)
+{
+  poly_dr_p pdr = XNEW (struct poly_dr);
+
+  PDR_PBB (pdr) = pbb;
+  PDR_ACCESSES (pdr) = accesses;
+  PDR_DATA_CONTAINER (pdr) = data_container;
+  PDR_TYPE (pdr) = type;
+  PDR_CDR (pdr) = cdr;
+  VEC_safe_push (poly_dr_p, heap, PBB_DRS (pbb), pdr);
+}
+
+/* Free polyhedral data reference PDR.  */
+
+void
+free_poly_dr (poly_dr_p pdr)
+{
+  ppl_delete_Pointset_Powerset_C_Polyhedron (PDR_ACCESSES (pdr));
+  ppl_delete_Pointset_Powerset_C_Polyhedron (PDR_DATA_CONTAINER (pdr));
+
+  XDELETE (pdr);
+}
+
+/* Create a new polyhedral black box.  */
+
+void
+new_poly_bb (scop_p scop, void *black_box)
+{
+  poly_bb_p pbb = XNEW (struct poly_bb);
+
+  PBB_DOMAIN (pbb) = NULL;
+  PBB_SCOP (pbb) = scop;
+  pbb_set_black_box (pbb, black_box);
+  PBB_TRANSFORMED_SCATTERING (pbb) = NULL;
+  PBB_ORIGINAL_SCATTERING (pbb) = NULL;
+  PBB_DRS (pbb) = VEC_alloc (poly_dr_p, heap, 3);
+  PBB_NB_SCATTERING_TRANSFORM (pbb) = 0;
+  PBB_NB_LOCAL_VARIABLES (pbb) = 0;
+  VEC_safe_push (poly_bb_p, heap, SCOP_BBS (scop), pbb);
+}
+
+/* Free polyhedral black box.  */
+
+void
+free_poly_bb (poly_bb_p pbb)
+{
+  int i;
+  poly_dr_p pdr;
+
+  ppl_delete_Pointset_Powerset_C_Polyhedron (PBB_DOMAIN (pbb));
+
+  if (PBB_TRANSFORMED_SCATTERING (pbb))
+    ppl_delete_Polyhedron (PBB_TRANSFORMED_SCATTERING (pbb));
+
+  if (PBB_ORIGINAL_SCATTERING (pbb))
+    ppl_delete_Polyhedron (PBB_ORIGINAL_SCATTERING (pbb));
+
+  if (PBB_DRS (pbb))
+    for (i = 0; VEC_iterate (poly_dr_p, PBB_DRS (pbb), i, pdr); i++)
+      free_poly_dr (pdr);
+
+  VEC_free (poly_dr_p, heap, PBB_DRS (pbb));
+  XDELETE (pbb);
+}
+
+static void
+print_pdr_access_layout (FILE *file, poly_dr_p pdr)
+{
+  graphite_dim_t i;
+
+  fprintf (file, "#  eq");
+
+  for (i = 0; i < pdr_dim_iter_domain (pdr); i++)
+    fprintf (file, "     i%d", (int) i);
+
+  for (i = 0; i < pdr_nb_params (pdr); i++)
+    fprintf (file, "     p%d", (int) i);
+
+  fprintf (file, "  alias");
+
+  for (i = 0; i < pdr_nb_subscripts (pdr); i++)
+    fprintf (file, "   sub%d", (int) i);
+
+  fprintf (file, "    cst\n");
+}
+
+/* Prints to FILE the polyhedral data reference PDR.  */
+
+void
+print_pdr (FILE *file, poly_dr_p pdr)
+{
+  fprintf (file, "pdr (");
+
+  switch (PDR_TYPE (pdr))
+    {
+    case PDR_READ:
+      fprintf (file, "read \n");
+      break;
+
+    case PDR_WRITE:
+      fprintf (file, "write \n");
+      break;
+
+    case PDR_MAY_WRITE:
+      fprintf (file, "may_write \n");
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+
+  dump_data_reference (file, (data_reference_p) PDR_CDR (pdr));
+
+  fprintf (file, "data accesses (\n");
+  print_pdr_access_layout (file, pdr);
+  ppl_print_powerset_matrix (file, PDR_ACCESSES (pdr));
+  fprintf (file, ")\n");
+
+  fprintf (file, "data container (\n");
+  print_pdr_access_layout (file, pdr);
+  ppl_print_powerset_matrix (file, PDR_DATA_CONTAINER (pdr));
+  fprintf (file, ")\n");
+
+  fprintf (file, ")\n");
+}
+
+/* Prints to STDERR the polyhedral data reference PDR.  */
+
+void
+debug_pdr (poly_dr_p pdr)
+{
+  print_pdr (stderr, pdr);
+}
+
+/* Creates a new SCOP containing REGION.  */
+
+scop_p
+new_scop (void *region)
+{
+  scop_p scop = XNEW (struct scop);
+
+  SCOP_DEP_GRAPH (scop) = NULL;
+  SCOP_CONTEXT (scop) = NULL;
+  scop_set_region (scop, region);
+  SCOP_BBS (scop) = VEC_alloc (poly_bb_p, heap, 3);
+  SCOP_ORIGINAL_PDR_PAIRS (scop) = htab_create (10, hash_poly_dr_pair_p,
+                                                eq_poly_dr_pair_p, free);
+  return scop;
+}
+
+/* Deletes SCOP.  */
+
+void
+free_scop (scop_p scop)
+{
+  int i;
+  poly_bb_p pbb;
+
+  for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
+    free_poly_bb (pbb);
+
+  VEC_free (poly_bb_p, heap, SCOP_BBS (scop));
+
+  if (SCOP_CONTEXT (scop))
+    ppl_delete_Pointset_Powerset_C_Polyhedron (SCOP_CONTEXT (scop));
+
+  htab_delete (SCOP_ORIGINAL_PDR_PAIRS (scop));
+  XDELETE (scop);
+}
+
+/* Print to FILE the domain of PBB.  */
+
+void
+print_pbb_domain (FILE *file, poly_bb_p pbb)
+{
+  graphite_dim_t i;
+  gimple_bb_p gbb = PBB_BLACK_BOX (pbb);
+
+  if (!PBB_DOMAIN (pbb))
+    return;
+
+  fprintf (file, "domains bb_%d (\n", GBB_BB (gbb)->index);
+  fprintf (file, "#  eq");
+
+  for (i = 0; i < pbb_dim_iter_domain (pbb); i++)
+    fprintf (file, "     i%d", (int) i);
+
+  for (i = 0; i < pbb_nb_params (pbb); i++)
+    fprintf (file, "     p%d", (int) i);
+
+  fprintf (file, "    cst\n");
+
+  if (PBB_DOMAIN (pbb))
+    ppl_print_powerset_matrix (file, PBB_DOMAIN (pbb));
+
+  fprintf (file, ")\n");
+}
+
+/* Dump the cases of a graphite basic block GBB on FILE.  */
+
+static void
+dump_gbb_cases (FILE *file, gimple_bb_p gbb)
+{
+  int i;
+  gimple stmt;
+  VEC (gimple, heap) *cases;
+
+  if (!gbb)
+    return;
+
+  cases = GBB_CONDITION_CASES (gbb);
+  if (VEC_empty (gimple, cases))
+    return;
+
+  fprintf (file, "cases bb_%d (", GBB_BB (gbb)->index);
+
+  for (i = 0; VEC_iterate (gimple, cases, i, stmt); i++)
+    print_gimple_stmt (file, stmt, 0, 0);
+
+  fprintf (file, ")\n");
+}
+
+/* Dump conditions of a graphite basic block GBB on FILE.  */
+
+static void
+dump_gbb_conditions (FILE *file, gimple_bb_p gbb)
+{
+  int i;
+  gimple stmt;
+  VEC (gimple, heap) *conditions;
+
+  if (!gbb)
+    return;
+
+  conditions = GBB_CONDITIONS (gbb);
+  if (VEC_empty (gimple, conditions))
+    return;
+
+  fprintf (file, "conditions bb_%d (", GBB_BB (gbb)->index);
+
+  for (i = 0; VEC_iterate (gimple, conditions, i, stmt); i++)
+    print_gimple_stmt (file, stmt, 0, 0);
+
+  fprintf (file, ")\n");
+}
+
+/* Print to FILE all the data references of PBB.  */
+
+void
+print_pdrs (FILE *file, poly_bb_p pbb)
+{
+  int i;
+  poly_dr_p pdr;
+
+  for (i = 0; VEC_iterate (poly_dr_p, PBB_DRS (pbb), i, pdr); i++)
+    print_pdr (file, pdr);
+}
+
+/* Print to STDERR all the data references of PBB.  */
+
+void
+debug_pdrs (poly_bb_p pbb)
+{
+  print_pdrs (stderr, pbb);
+}
+
+/* Print to FILE the domain and scattering function of PBB.  */
+
+void
+print_pbb (FILE *file, poly_bb_p pbb)
+{
+  dump_gbb_conditions (file, PBB_BLACK_BOX (pbb));
+  dump_gbb_cases (file, PBB_BLACK_BOX (pbb));
+  print_pdrs (file, pbb);
+  print_pbb_domain (file, pbb);
+  print_scattering_function (file, pbb);
+}
+
+/* Print to FILE the parameters of SCOP.  */
+
+void
+print_scop_params (FILE *file, scop_p scop)
+{
+  int i;
+  tree t;
+
+  fprintf (file, "parameters (\n");
+  for (i = 0; VEC_iterate (tree, SESE_PARAMS (SCOP_REGION (scop)), i, t); i++)
+    {
+      fprintf (file, "p_%d -> ", i);
+      print_generic_expr (file, t, 0);
+      fprintf (file, "\n");
+    }
+  fprintf (file, ")\n");
+}
+
+/* Print to FILE the context of SCoP.  */
+void
+print_scop_context (FILE *file, scop_p scop)
+{
+  graphite_dim_t i;
+
+  fprintf (file, "context (\n");
+  fprintf (file, "#  eq");
+
+  for (i = 0; i < scop_nb_params (scop); i++)
+    fprintf (file, "     p%d", (int) i);
+
+  fprintf (file, "    cst\n");
+
+  if (SCOP_CONTEXT (scop))
+    ppl_print_powerset_matrix (file, SCOP_CONTEXT (scop));
+
+  fprintf (file, ")\n");
+}
+
+/* Print to FILE the SCOP.  */
+
+void
+print_scop (FILE *file, scop_p scop)
+{
+  int i;
+  poly_bb_p pbb;
+
+  print_scop_params (file, scop);
+  print_scop_context (file, scop);
+
+  for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
+    print_pbb (file, pbb);
+}
+
+/* Print to STDERR the domain of PBB.  */
+
+void
+debug_pbb_domain (poly_bb_p pbb)
+{
+  print_pbb_domain (stderr, pbb);
+}
+
+/* Print to FILE the domain and scattering function of PBB.  */
+
+void
+debug_pbb (poly_bb_p pbb)
+{
+  print_pbb (stderr, pbb);
+}
+
+/* Print to STDERR the context of SCOP.  */
+
+void
+debug_scop_context (scop_p scop)
+{
+  print_scop_context (stderr, scop);
+}
+
+/* Print to STDERR the SCOP.  */
+
+void
+debug_scop (scop_p scop)
+{
+  print_scop (stderr, scop);
+}
+
+/* Print to STDERR the parameters of SCOP.  */
+
+void
+debug_scop_params (scop_p scop)
+{
+  print_scop_params (stderr, scop);
+}
+
+
+/* The dimension in the transformed scattering polyhedron of PBB
+   containing the scattering iterator for the loop at depth LOOP_DEPTH.  */
+
+ppl_dimension_type
+psct_scattering_dim_for_loop_depth (poly_bb_p pbb, graphite_dim_t loop_depth)
+{
+  ppl_const_Constraint_System_t pcs;
+  ppl_Constraint_System_const_iterator_t cit, cend;
+  ppl_const_Constraint_t cstr;
+  ppl_Polyhedron_t ph = PBB_TRANSFORMED_SCATTERING (pbb);
+  ppl_dimension_type iter = psct_iterator_dim (pbb, loop_depth);
+  ppl_Linear_Expression_t expr;
+  ppl_Coefficient_t coef;
+  Value val;
+  graphite_dim_t i;
+
+  value_init (val);
+  ppl_new_Coefficient (&coef);
+  ppl_Polyhedron_get_constraints (ph, &pcs);
+  ppl_new_Constraint_System_const_iterator (&cit);
+  ppl_new_Constraint_System_const_iterator (&cend);
+
+  for (ppl_Constraint_System_begin (pcs, cit),
+	 ppl_Constraint_System_end (pcs, cend);
+       !ppl_Constraint_System_const_iterator_equal_test (cit, cend);
+       ppl_Constraint_System_const_iterator_increment (cit))
+    {
+      ppl_Constraint_System_const_iterator_dereference (cit, &cstr);
+      ppl_new_Linear_Expression_from_Constraint (&expr, cstr);
+      ppl_Linear_Expression_coefficient (expr, iter, coef);
+      ppl_Coefficient_to_mpz_t (coef, val);
+
+      if (value_zero_p (val))
+	{
+	  ppl_delete_Linear_Expression (expr);
+	  continue;
+	}
+
+      for (i = 0; i < pbb_nb_scattering_transform (pbb); i++)
+	{
+	  ppl_dimension_type scatter = psct_scattering_dim (pbb, i);
+
+	  ppl_Linear_Expression_coefficient (expr, scatter, coef);
+	  ppl_Coefficient_to_mpz_t (coef, val);
+
+	  if (value_notzero_p (val))
+	    {
+	      value_clear (val);
+	      ppl_delete_Linear_Expression (expr);
+	      ppl_delete_Coefficient (coef);
+	      ppl_delete_Constraint_System_const_iterator (cit);
+	      ppl_delete_Constraint_System_const_iterator (cend);
+
+	      return scatter;
+	    }
+	}
+    }
+
+  gcc_unreachable ();
+}
+
+/* Returns the number of iterations NITER of the loop around PBB at
+   depth LOOP_DEPTH.  */
+
+void
+pbb_number_of_iterations (poly_bb_p pbb,
+			  graphite_dim_t loop_depth,
+			  Value niter)
+{
+  ppl_dimension_type loop_iter = pbb_iterator_dim (pbb, loop_depth);
+  ppl_Linear_Expression_t le;
+  ppl_Coefficient_t num, denom;
+  Value dv;
+  int maximum;
+  ppl_dimension_type dim;
+
+  value_init (dv);
+  ppl_new_Coefficient (&num);
+  ppl_new_Coefficient (&denom);
+  ppl_Pointset_Powerset_C_Polyhedron_space_dimension (PBB_DOMAIN (pbb), &dim);
+  ppl_new_Linear_Expression_with_dimension (&le, dim);
+  ppl_set_coef (le, loop_iter, 1);
+  ppl_Pointset_Powerset_C_Polyhedron_maximize (PBB_DOMAIN (pbb), le,
+					       num, denom, &maximum);
+
+  if (maximum == 1)
+    {
+      ppl_Coefficient_to_mpz_t (num, niter);
+      ppl_Coefficient_to_mpz_t (denom, dv);
+      value_division (niter, niter, dv);
+    }
+  else
+    value_set_si (niter, -1);
+
+  value_clear (dv);
+  ppl_delete_Linear_Expression (le);
+  ppl_delete_Coefficient (num);
+  ppl_delete_Coefficient (denom);
+}
+
+#endif
+