Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 650 insertions, 0 deletions

diff --git a/gcc-4.9/gcc/graphite-interchange.c b/gcc-4.9/gcc/graphite-interchange.c
new file mode 100644
index 000000000..55e3fab89
--- /dev/null
+++ b/gcc-4.9/gcc/graphite-interchange.c
@@ -0,0 +1,650 @@
+/* Interchange heuristics and transform for loop interchange on
+   polyhedral representation.
+
+   Copyright (C) 2009-2014 Free Software Foundation, Inc.
+   Contributed by Sebastian Pop <sebastian.pop@amd.com> and
+   Harsha Jagasia <harsha.jagasia@amd.com>.
+
+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"
+
+#ifdef HAVE_cloog
+#include <isl/aff.h>
+#include <isl/set.h>
+#include <isl/map.h>
+#include <isl/union_map.h>
+#include <isl/ilp.h>
+#include <cloog/cloog.h>
+#include <cloog/isl/domain.h>
+#endif
+
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+#include "basic-block.h"
+#include "tree-ssa-alias.h"
+#include "internal-fn.h"
+#include "gimple-expr.h"
+#include "is-a.h"
+#include "gimple.h"
+#include "gimple-iterator.h"
+#include "tree-ssa-loop.h"
+#include "dumpfile.h"
+#include "cfgloop.h"
+#include "tree-chrec.h"
+#include "tree-data-ref.h"
+#include "tree-scalar-evolution.h"
+#include "sese.h"
+
+#ifdef HAVE_cloog
+#include "graphite-poly.h"
+
+/* XXX isl rewrite following comment */
+/* Builds a linear expression, of dimension DIM, representing PDR's
+   memory access:
+
+   L = r_{n}*r_{n-1}*...*r_{1}*s_{0} + ... + r_{n}*s_{n-1} + s_{n}.
+
+   For an array A[10][20] with two subscript locations s0 and s1, the
+   linear memory access is 20 * s0 + s1: a stride of 1 in subscript s0
+   corresponds to a memory stride of 20.
+
+   OFFSET is a number of dimensions to prepend before the
+   subscript dimensions: s_0, s_1, ..., s_n.
+
+   Thus, the final linear expression has the following format:
+   0 .. 0_{offset} | 0 .. 0_{nit} | 0 .. 0_{gd} | 0 | c_0 c_1 ... c_n
+   where the expression itself is:
+   c_0 * s_0 + c_1 * s_1 + ... c_n * s_n.  */
+
+static isl_constraint *
+build_linearized_memory_access (isl_map *map, poly_dr_p pdr)
+{
+  isl_constraint *res;
+  isl_local_space *ls = isl_local_space_from_space (isl_map_get_space (map));
+  unsigned offset, nsubs;
+  int i;
+  isl_int size, subsize;
+
+  res = isl_equality_alloc (ls);
+  isl_int_init (size);
+  isl_int_set_ui (size, 1);
+  isl_int_init (subsize);
+  isl_int_set_ui (subsize, 1);
+
+  nsubs = isl_set_dim (pdr->extent, isl_dim_set);
+  /* -1 for the already included L dimension.  */
+  offset = isl_map_dim (map, isl_dim_out) - 1 - nsubs;
+  res = isl_constraint_set_coefficient_si (res, isl_dim_out, offset + nsubs, -1);
+  /* Go through all subscripts from last to first.  First dimension
+     is the alias set, ignore it.  */
+  for (i = nsubs - 1; i >= 1; i--)
+    {
+      isl_space *dc;
+      isl_aff *aff;
+
+      res = isl_constraint_set_coefficient (res, isl_dim_out, offset + i, size);
+
+      dc = isl_set_get_space (pdr->extent);
+      aff = isl_aff_zero_on_domain (isl_local_space_from_space (dc));
+      aff = isl_aff_set_coefficient_si (aff, isl_dim_in, i, 1);
+      isl_set_max (pdr->extent, aff, &subsize);
+      isl_aff_free (aff);
+      isl_int_mul (size, size, subsize);
+    }
+
+  isl_int_clear (subsize);
+  isl_int_clear (size);
+
+  return res;
+}
+
+/* Set STRIDE to the stride of PDR in memory by advancing by one in
+   the loop at DEPTH.  */
+
+static void
+pdr_stride_in_loop (mpz_t stride, graphite_dim_t depth, poly_dr_p pdr)
+{
+  poly_bb_p pbb = PDR_PBB (pdr);
+  isl_map *map;
+  isl_set *set;
+  isl_aff *aff;
+  isl_space *dc;
+  isl_constraint *lma, *c;
+  isl_int islstride;
+  graphite_dim_t time_depth;
+  unsigned offset, nt;
+  unsigned i;
+  /* XXX isl rewrite following comments.  */
+  /* Builds a partial difference equations and inserts them
+     into pointset powerset polyhedron P.  Polyhedron is assumed
+     to have the format: T|I|T'|I'|G|S|S'|l1|l2.
+
+     TIME_DEPTH is the time dimension w.r.t. which we are
+     differentiating.
+     OFFSET represents the number of dimensions between
+     columns t_{time_depth} and t'_{time_depth}.
+     DIM_SCTR is the number of scattering dimensions.  It is
+     essentially the dimensionality of the T vector.
+
+     The following equations are inserted into the polyhedron P:
+     | t_1 = t_1'
+     | ...
+     | t_{time_depth-1} = t'_{time_depth-1}
+     | t_{time_depth} = t'_{time_depth} + 1
+     | t_{time_depth+1} = t'_{time_depth + 1}
+     | ...
+     | t_{dim_sctr} = t'_{dim_sctr}.  */
+
+  /* Add the equality: t_{time_depth} = t'_{time_depth} + 1.
+     This is the core part of this alogrithm, since this
+     constraint asks for the memory access stride (difference)
+     between two consecutive points in time dimensions.  */
+
+  /* Add equalities:
+     | t1 = t1'
+     | ...
+     | t_{time_depth-1} = t'_{time_depth-1}
+     | t_{time_depth+1} = t'_{time_depth+1}
+     | ...
+     | t_{dim_sctr} = t'_{dim_sctr}
+
+     This means that all the time dimensions are equal except for
+     time_depth, where the constraint is t_{depth} = t'_{depth} + 1
+     step.  More to this: we should be careful not to add equalities
+     to the 'coupled' dimensions, which happens when the one dimension
+     is stripmined dimension, and the other dimension corresponds
+     to the point loop inside stripmined dimension.  */
+
+  /* pdr->accesses:    [P1..nb_param,I1..nb_domain]->[a,S1..nb_subscript]
+          ??? [P] not used for PDRs?
+     pdr->extent:      [a,S1..nb_subscript]
+     pbb->domain:      [P1..nb_param,I1..nb_domain]
+     pbb->transformed: [P1..nb_param,I1..nb_domain]->[T1..Tnb_sctr]
+          [T] includes local vars (currently unused)
+     
+     First we create [P,I] -> [T,a,S].  */
+  
+  map = isl_map_flat_range_product (isl_map_copy (pbb->transformed),
+				    isl_map_copy (pdr->accesses));
+  /* Add a dimension for L: [P,I] -> [T,a,S,L].*/
+  map = isl_map_add_dims (map, isl_dim_out, 1);
+  /* Build a constraint for "lma[S] - L == 0", effectively calculating
+     L in terms of subscripts.  */
+  lma = build_linearized_memory_access (map, pdr);
+  /* And add it to the map, so we now have:
+     [P,I] -> [T,a,S,L] : lma([S]) == L.  */
+  map = isl_map_add_constraint (map, lma);
+
+  /* Then we create  [P,I,P',I'] -> [T,a,S,L,T',a',S',L'].  */
+  map = isl_map_flat_product (map, isl_map_copy (map));
+
+  /* Now add the equality T[time_depth] == T'[time_depth]+1.  This will
+     force L' to be the linear address at T[time_depth] + 1. */
+  time_depth = psct_dynamic_dim (pbb, depth);
+  /* Length of [a,S] plus [L] ...  */
+  offset = 1 + isl_map_dim (pdr->accesses, isl_dim_out);
+  /* ... plus [T].  */
+  offset += isl_map_dim (pbb->transformed, isl_dim_out);
+
+  c = isl_equality_alloc (isl_local_space_from_space (isl_map_get_space (map)));
+  c = isl_constraint_set_coefficient_si (c, isl_dim_out, time_depth, 1);
+  c = isl_constraint_set_coefficient_si (c, isl_dim_out,
+					 offset + time_depth, -1);
+  c = isl_constraint_set_constant_si (c, 1);
+  map = isl_map_add_constraint (map, c);
+
+  /* Now we equate most of the T/T' elements (making PITaSL nearly
+     the same is (PITaSL)', except for one dimension, namely for 'depth'
+     (an index into [I]), after translating to index into [T].  Take care
+     to not produce an empty map, which indicates we wanted to equate
+     two dimensions that are already coupled via the above time_depth
+     dimension.  Happens with strip mining where several scatter dimension
+     are interdependend.  */
+  /* Length of [T].  */
+  nt = pbb_nb_scattering_transform (pbb) + pbb_nb_local_vars (pbb);
+  for (i = 0; i < nt; i++)
+    if (i != time_depth)
+      {
+	isl_map *temp = isl_map_equate (isl_map_copy (map),
+					isl_dim_out, i,
+					isl_dim_out, offset + i);
+	if (isl_map_is_empty (temp))
+	  isl_map_free (temp);
+	else
+	  {
+	    isl_map_free (map);
+	    map = temp;
+	  }
+      }
+
+  /* Now maximize the expression L' - L.  */
+  set = isl_map_range (map);
+  dc = isl_set_get_space (set);
+  aff = isl_aff_zero_on_domain (isl_local_space_from_space (dc));
+  aff = isl_aff_set_coefficient_si (aff, isl_dim_in, offset - 1, -1);
+  aff = isl_aff_set_coefficient_si (aff, isl_dim_in, offset + offset - 1, 1);
+  isl_int_init (islstride);
+  isl_set_max (set, aff, &islstride);
+  isl_int_get_gmp (islstride, stride);
+  isl_int_clear (islstride);
+  isl_aff_free (aff);
+  isl_set_free (set);
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    {
+      gmp_fprintf (dump_file, "\nStride in BB_%d, DR_%d, depth %d:  %Zd ",
+		   pbb_index (pbb), PDR_ID (pdr), (int) depth, stride);
+    }
+}
+
+/* Sets STRIDES to the sum of all the strides of the data references
+   accessed in LOOP at DEPTH.  */
+
+static void
+memory_strides_in_loop_1 (lst_p loop, graphite_dim_t depth, mpz_t strides)
+{
+  int i, j;
+  lst_p l;
+  poly_dr_p pdr;
+  mpz_t s, n;
+
+  mpz_init (s);
+  mpz_init (n);
+
+  FOR_EACH_VEC_ELT (LST_SEQ (loop), j, l)
+    if (LST_LOOP_P (l))
+      memory_strides_in_loop_1 (l, depth, strides);
+    else
+      FOR_EACH_VEC_ELT (PBB_DRS (LST_PBB (l)), i, pdr)
+	{
+	  pdr_stride_in_loop (s, depth, pdr);
+	  mpz_set_si (n, PDR_NB_REFS (pdr));
+	  mpz_mul (s, s, n);
+	  mpz_add (strides, strides, s);
+	}
+
+  mpz_clear (s);
+  mpz_clear (n);
+}
+
+/* Sets STRIDES to the sum of all the strides of the data references
+   accessed in LOOP at DEPTH.  */
+
+static void
+memory_strides_in_loop (lst_p loop, graphite_dim_t depth, mpz_t strides)
+{
+  if (mpz_cmp_si (loop->memory_strides, -1) == 0)
+    {
+      mpz_set_si (strides, 0);
+      memory_strides_in_loop_1 (loop, depth, strides);
+    }
+  else
+    mpz_set (strides, loop->memory_strides);
+}
+
+/* Return true when the interchange of loops LOOP1 and LOOP2 is
+   profitable.
+
+   Example:
+
+   | int a[100][100];
+   |
+   | int
+   | foo (int N)
+   | {
+   |   int j;
+   |   int i;
+   |
+   |   for (i = 0; i < N; i++)
+   |     for (j = 0; j < N; j++)
+   |       a[j][2 * i] += 1;
+   |
+   |   return a[N][12];
+   | }
+
+   The data access A[j][i] is described like this:
+
+   | i   j   N   a  s0  s1   1
+   | 0   0   0   1   0   0  -5    = 0
+   | 0  -1   0   0   1   0   0    = 0
+   |-2   0   0   0   0   1   0    = 0
+   | 0   0   0   0   1   0   0   >= 0
+   | 0   0   0   0   0   1   0   >= 0
+   | 0   0   0   0  -1   0 100   >= 0
+   | 0   0   0   0   0  -1 100   >= 0
+
+   The linearized memory access L to A[100][100] is:
+
+   | i   j   N   a  s0  s1   1
+   | 0   0   0   0 100   1   0
+
+   TODO: the shown format is not valid as it does not show the fact
+   that the iteration domain "i j" is transformed using the scattering.
+
+   Next, to measure the impact of iterating once in loop "i", we build
+   a maximization problem: first, we add to DR accesses the dimensions
+   k, s2, s3, L1 = 100 * s0 + s1, L2, and D1: this is the polyhedron P1.
+   L1 and L2 are the linearized memory access functions.
+
+   | i   j   N   a  s0  s1   k  s2  s3  L1  L2  D1   1
+   | 0   0   0   1   0   0   0   0   0   0   0   0  -5    = 0  alias = 5
+   | 0  -1   0   0   1   0   0   0   0   0   0   0   0    = 0  s0 = j
+   |-2   0   0   0   0   1   0   0   0   0   0   0   0    = 0  s1 = 2 * i
+   | 0   0   0   0   1   0   0   0   0   0   0   0   0   >= 0
+   | 0   0   0   0   0   1   0   0   0   0   0   0   0   >= 0
+   | 0   0   0   0  -1   0   0   0   0   0   0   0 100   >= 0
+   | 0   0   0   0   0  -1   0   0   0   0   0   0 100   >= 0
+   | 0   0   0   0 100   1   0   0   0  -1   0   0   0    = 0  L1 = 100 * s0 + s1
+
+   Then, we generate the polyhedron P2 by interchanging the dimensions
+   (s0, s2), (s1, s3), (L1, L2), (k, i)
+
+   | i   j   N   a  s0  s1   k  s2  s3  L1  L2  D1   1
+   | 0   0   0   1   0   0   0   0   0   0   0   0  -5    = 0  alias = 5
+   | 0  -1   0   0   0   0   0   1   0   0   0   0   0    = 0  s2 = j
+   | 0   0   0   0   0   0  -2   0   1   0   0   0   0    = 0  s3 = 2 * k
+   | 0   0   0   0   0   0   0   1   0   0   0   0   0   >= 0
+   | 0   0   0   0   0   0   0   0   1   0   0   0   0   >= 0
+   | 0   0   0   0   0   0   0  -1   0   0   0   0 100   >= 0
+   | 0   0   0   0   0   0   0   0  -1   0   0   0 100   >= 0
+   | 0   0   0   0   0   0   0 100   1   0  -1   0   0    = 0  L2 = 100 * s2 + s3
+
+   then we add to P2 the equality k = i + 1:
+
+   |-1   0   0   0   0   0   1   0   0   0   0   0  -1    = 0  k = i + 1
+
+   and finally we maximize the expression "D1 = max (P1 inter P2, L2 - L1)".
+
+   Similarly, to determine the impact of one iteration on loop "j", we
+   interchange (k, j), we add "k = j + 1", and we compute D2 the
+   maximal value of the difference.
+
+   Finally, the profitability test is D1 < D2: if in the outer loop
+   the strides are smaller than in the inner loop, then it is
+   profitable to interchange the loops at DEPTH1 and DEPTH2.  */
+
+static bool
+lst_interchange_profitable_p (lst_p nest, int depth1, int depth2)
+{
+  mpz_t d1, d2;
+  bool res;
+
+  gcc_assert (depth1 < depth2);
+
+  mpz_init (d1);
+  mpz_init (d2);
+
+  memory_strides_in_loop (nest, depth1, d1);
+  memory_strides_in_loop (nest, depth2, d2);
+
+  res = mpz_cmp (d1, d2) < 0;
+
+  mpz_clear (d1);
+  mpz_clear (d2);
+
+  return res;
+}
+
+/* Interchanges the loops at DEPTH1 and DEPTH2 of the original
+   scattering and assigns the resulting polyhedron to the transformed
+   scattering.  */
+
+static void
+pbb_interchange_loop_depths (graphite_dim_t depth1, graphite_dim_t depth2,
+			     poly_bb_p pbb)
+{
+  unsigned i;
+  unsigned dim1 = psct_dynamic_dim (pbb, depth1);
+  unsigned dim2 = psct_dynamic_dim (pbb, depth2);
+  isl_space *d = isl_map_get_space (pbb->transformed);
+  isl_space *d1 = isl_space_range (d);
+  unsigned n = isl_space_dim (d1, isl_dim_out);
+  isl_space *d2 = isl_space_add_dims (d1, isl_dim_in, n);
+  isl_map *x = isl_map_universe (d2);
+
+  x = isl_map_equate (x, isl_dim_in, dim1, isl_dim_out, dim2);
+  x = isl_map_equate (x, isl_dim_in, dim2, isl_dim_out, dim1);
+
+  for (i = 0; i < n; i++)
+    if (i != dim1 && i != dim2)
+      x = isl_map_equate (x, isl_dim_in, i, isl_dim_out, i);
+
+  pbb->transformed = isl_map_apply_range (pbb->transformed, x);
+}
+
+/* Apply the interchange of loops at depths DEPTH1 and DEPTH2 to all
+   the statements below LST.  */
+
+static void
+lst_apply_interchange (lst_p lst, int depth1, int depth2)
+{
+  if (!lst)
+    return;
+
+  if (LST_LOOP_P (lst))
+    {
+      int i;
+      lst_p l;
+
+      FOR_EACH_VEC_ELT (LST_SEQ (lst), i, l)
+	lst_apply_interchange (l, depth1, depth2);
+    }
+  else
+    pbb_interchange_loop_depths (depth1, depth2, LST_PBB (lst));
+}
+
+/* Return true when the nest starting at LOOP1 and ending on LOOP2 is
+   perfect: i.e. there are no sequence of statements.  */
+
+static bool
+lst_perfectly_nested_p (lst_p loop1, lst_p loop2)
+{
+  if (loop1 == loop2)
+    return true;
+
+  if (!LST_LOOP_P (loop1))
+    return false;
+
+  return LST_SEQ (loop1).length () == 1
+         && lst_perfectly_nested_p (LST_SEQ (loop1)[0], loop2);
+}
+
+/* Transform the loop nest between LOOP1 and LOOP2 into a perfect
+   nest.  To continue the naming tradition, this function is called
+   after perfect_nestify.  NEST is set to the perfectly nested loop
+   that is created.  BEFORE/AFTER are set to the loops distributed
+   before/after the loop NEST.  */
+
+static void
+lst_perfect_nestify (lst_p loop1, lst_p loop2, lst_p *before,
+		     lst_p *nest, lst_p *after)
+{
+  poly_bb_p first, last;
+
+  gcc_assert (loop1 && loop2
+	      && loop1 != loop2
+	      && LST_LOOP_P (loop1) && LST_LOOP_P (loop2));
+
+  first = LST_PBB (lst_find_first_pbb (loop2));
+  last = LST_PBB (lst_find_last_pbb (loop2));
+
+  *before = copy_lst (loop1);
+  *nest = copy_lst (loop1);
+  *after = copy_lst (loop1);
+
+  lst_remove_all_before_including_pbb (*before, first, false);
+  lst_remove_all_before_including_pbb (*after, last, true);
+
+  lst_remove_all_before_excluding_pbb (*nest, first, true);
+  lst_remove_all_before_excluding_pbb (*nest, last, false);
+
+  if (lst_empty_p (*before))
+    {
+      free_lst (*before);
+      *before = NULL;
+    }
+  if (lst_empty_p (*after))
+    {
+      free_lst (*after);
+      *after = NULL;
+    }
+  if (lst_empty_p (*nest))
+    {
+      free_lst (*nest);
+      *nest = NULL;
+    }
+}
+
+/* Try to interchange LOOP1 with LOOP2 for all the statements of the
+   body of LOOP2.  LOOP1 contains LOOP2.  Return true if it did the
+   interchange.  */
+
+static bool
+lst_try_interchange_loops (scop_p scop, lst_p loop1, lst_p loop2)
+{
+  int depth1 = lst_depth (loop1);
+  int depth2 = lst_depth (loop2);
+  lst_p transformed;
+
+  lst_p before = NULL, nest = NULL, after = NULL;
+
+  if (!lst_perfectly_nested_p (loop1, loop2))
+    lst_perfect_nestify (loop1, loop2, &before, &nest, &after);
+
+  if (!lst_interchange_profitable_p (loop2, depth1, depth2))
+    return false;
+
+  lst_apply_interchange (loop2, depth1, depth2);
+
+  /* Sync the transformed LST information and the PBB scatterings
+     before using the scatterings in the data dependence analysis.  */
+  if (before || nest || after)
+    {
+      transformed = lst_substitute_3 (SCOP_TRANSFORMED_SCHEDULE (scop), loop1,
+				      before, nest, after);
+      lst_update_scattering (transformed);
+      free_lst (transformed);
+    }
+
+  if (graphite_legal_transform (scop))
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file,
+		 "Loops at depths %d and %d will be interchanged.\n",
+		 depth1, depth2);
+
+      /* Transform the SCOP_TRANSFORMED_SCHEDULE of the SCOP.  */
+      lst_insert_in_sequence (before, loop1, true);
+      lst_insert_in_sequence (after, loop1, false);
+
+      if (nest)
+	{
+	  lst_replace (loop1, nest);
+	  free_lst (loop1);
+	}
+
+      return true;
+    }
+
+  /* Undo the transform.  */
+  free_lst (before);
+  free_lst (nest);
+  free_lst (after);
+  lst_apply_interchange (loop2, depth2, depth1);
+  return false;
+}
+
+/* Selects the inner loop in LST_SEQ (INNER_FATHER) to be interchanged
+   with the loop OUTER in LST_SEQ (OUTER_FATHER).  */
+
+static bool
+lst_interchange_select_inner (scop_p scop, lst_p outer_father, int outer,
+			      lst_p inner_father)
+{
+  int inner;
+  lst_p loop1, loop2;
+
+  gcc_assert (outer_father
+	      && LST_LOOP_P (outer_father)
+	      && LST_LOOP_P (LST_SEQ (outer_father)[outer])
+	      && inner_father
+	      && LST_LOOP_P (inner_father));
+
+  loop1 = LST_SEQ (outer_father)[outer];
+
+  FOR_EACH_VEC_ELT (LST_SEQ (inner_father), inner, loop2)
+    if (LST_LOOP_P (loop2)
+	&& (lst_try_interchange_loops (scop, loop1, loop2)
+	    || lst_interchange_select_inner (scop, outer_father, outer, loop2)))
+      return true;
+
+  return false;
+}
+
+/* Interchanges all the loops of LOOP and the loops of its body that
+   are considered profitable to interchange.  Return the number of
+   interchanged loops.  OUTER is the index in LST_SEQ (LOOP) that
+   points to the next outer loop to be considered for interchange.  */
+
+static int
+lst_interchange_select_outer (scop_p scop, lst_p loop, int outer)
+{
+  lst_p l;
+  int res = 0;
+  int i = 0;
+  lst_p father;
+
+  if (!loop || !LST_LOOP_P (loop))
+    return 0;
+
+  father = LST_LOOP_FATHER (loop);
+  if (father)
+    {
+      while (lst_interchange_select_inner (scop, father, outer, loop))
+	{
+	  res++;
+	  loop = LST_SEQ (father)[outer];
+	}
+    }
+
+  if (LST_LOOP_P (loop))
+    FOR_EACH_VEC_ELT (LST_SEQ (loop), i, l)
+      if (LST_LOOP_P (l))
+	res += lst_interchange_select_outer (scop, l, i);
+
+  return res;
+}
+
+/* Interchanges all the loop depths that are considered profitable for
+   SCOP.  Return the number of interchanged loops.  */
+
+int
+scop_do_interchange (scop_p scop)
+{
+  int res = lst_interchange_select_outer
+    (scop, SCOP_TRANSFORMED_SCHEDULE (scop), 0);
+
+  lst_update_scattering (SCOP_TRANSFORMED_SCHEDULE (scop));
+
+  return res;
+}
+
+
+#endif
+