remove unused

[cloog-ppl.git] / source / ppl / domain.c

   /**-------------------------------------------------------------------**
    **                               CLooG                               **
    **-------------------------------------------------------------------**
    **                             domain.c                              **
    **-------------------------------------------------------------------**
    **                   First version: october 28th 2001                **
    **-------------------------------------------------------------------**/


/******************************************************************************
 *               CLooG : the Chunky Loop Generator (experimental)             *
 ******************************************************************************
 *                                                                            *
 * Copyright (C) 2001-2005 Cedric Bastoul                                     *
 *                                                                            *
 * This 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 2 of the License, or (at your option) any later *
 * version.                                                                   *
 *                                                                            *
 * This software 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 software; if not, write to the Free Software Foundation, Inc.,        *
 * 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA                     *
 *                                                                            *
 * CLooG, the Chunky Loop Generator                                           *
 * Written by Cedric Bastoul, Cedric.Bastoul@inria.fr                         *
 *                                                                            *
 ******************************************************************************/
/* CAUTION: the english used for comments is probably the worst you ever read,
 *          please feel free to correct and improve it !
 */


# include <stdlib.h>
# include <stdio.h>
# include <ctype.h>
# include "../../include/cloog/cloog.h"
#include "matrix.h"


static int cloog_check_polyhedral_ops = 1;
static int cloog_return_ppl_result = 0;

/* Variables names for pretty printing.  */
static char wild_name[200][40];

static inline const char*
variable_output_function (ppl_dimension_type var)
{
  if (var < 40)
    return wild_name[var + 1];
  else
    return 0;
}

static inline void
error_handler (enum ppl_enum_error_code code, const char* description)
{
  fprintf (stderr, "PPL error code %d\n%s", code, description);
  exit (1);
}

void
cloog_initialize (void)
{
  sprintf (wild_name[0], "1");
  sprintf (wild_name[1], "a");
  sprintf (wild_name[2], "b");
  sprintf (wild_name[3], "c");
  sprintf (wild_name[4], "d");
  sprintf (wild_name[5], "e");
  sprintf (wild_name[6], "f");
  sprintf (wild_name[7], "g");
  sprintf (wild_name[8], "h");
  sprintf (wild_name[9], "i");
  sprintf (wild_name[10], "j");
  sprintf (wild_name[11], "k");
  sprintf (wild_name[12], "l");
  sprintf (wild_name[13], "m");
  sprintf (wild_name[14], "n");
  sprintf (wild_name[15], "o");
  sprintf (wild_name[16], "p");
  sprintf (wild_name[17], "q");
  sprintf (wild_name[18], "r");
  sprintf (wild_name[19], "s");
  sprintf (wild_name[20], "t");
  sprintf (wild_name[21], "alpha");
  sprintf (wild_name[22], "beta");
  sprintf (wild_name[23], "gamma");
  sprintf (wild_name[24], "delta");
  sprintf (wild_name[25], "tau");
  sprintf (wild_name[26], "sigma");
  sprintf (wild_name[27], "chi");
  sprintf (wild_name[28], "omega");
  sprintf (wild_name[29], "pi");
  sprintf (wild_name[30], "ni");
  sprintf (wild_name[31], "Alpha");
  sprintf (wild_name[32], "Beta");
  sprintf (wild_name[33], "Gamma");
  sprintf (wild_name[34], "Delta");
  sprintf (wild_name[35], "Tau");
  sprintf (wild_name[36], "Sigma");
  sprintf (wild_name[37], "Chi");
  sprintf (wild_name[38], "Omega");
  sprintf (wild_name[39], "xxx");

  if (ppl_initialize() < 0)
    {
      fprintf (stderr, "Cannot initialize the Parma Polyhedra Library.\n");
      exit (1);
    }

  if (ppl_set_error_handler (error_handler) < 0)
    {
      fprintf (stderr, "Cannot install the custom error handler.\n");
      exit (1);
    }

  if (ppl_io_set_variable_output_function (variable_output_function) < 0)
    {
      fprintf (stderr, "Cannot install the PPL custom variable output function. \n");
      exit (1);
    }
}

/**
 * The maximal number of rays allowed to be allocated by PolyLib. In fact since
 * version 5.20, PolyLib automatically tune the number of rays by multiplying
 * by 2 this number each time the maximum is reached. For unknown reasons
 * PolyLib makes a segmentation fault if this number is too small. If this
 * number is too small, performances will be reduced, if it is too high, memory
 * will be saturated. Note that the option "-rays X" set this number to X.
 */
int MAX_RAYS = 50;

/* Unused in this backend.  */

int cloog_domain_allocated = 0;
int cloog_domain_freed = 0;
int cloog_domain_max = 0;

/* The same for Value variables since in GMP mode they have to be freed. */
int cloog_value_allocated = 0;
int cloog_value_freed = 0;
int cloog_value_max = 0;


void
cloog_value_leak_up ()
{
  cloog_value_allocated++;
  if ((cloog_value_allocated - cloog_value_freed) > cloog_value_max)
    cloog_value_max = cloog_value_allocated - cloog_value_freed;
}


void
cloog_value_leak_down ()
{
  cloog_value_freed++;
}

static inline Polyhedron *
cloog_domain_polyhedron_set (CloogDomain * d, Polyhedron * p)
{
  return d->_polyhedron = p;
}

static inline void
cloog_domain_set_references (CloogDomain * d, int i)
{
  d->_references = i;
}

/**
 * cloog_domain_malloc function:
 * This function allocates the memory space for a CloogDomain structure and
 * sets its fields with default values. Then it returns a pointer to the
 * allocated space.
 * - November 21th 2005: first version.
 */
static CloogDomain *
cloog_domain_malloc ()
{
  CloogDomain *domain;

  domain = (CloogDomain *) malloc (sizeof (CloogDomain));
  if (domain == NULL)
    {
      fprintf (stderr, "[CLooG]ERROR: memory overflow.\n");
      exit (1);
    }

  /* We set the various fields with default values. */
  cloog_domain_polyhedron_set (domain, NULL);
  cloog_domain_set_references (domain, 1);

  return domain;
}


/**
 * cloog_domain_alloc function:
 * This function allocates the memory space for a CloogDomain structure and
 * sets its fields with those given as input. Then it returns a pointer to the
 * allocated space.
 * - April    19th 2005: first version.
 * - November 21th 2005: cloog_domain_malloc use.
 */
static CloogDomain *
cloog_domain_alloc (Polyhedron * polyhedron)
{
  CloogDomain *domain;

  if (polyhedron == NULL)
    return NULL;
  else
    {
      domain = cloog_domain_malloc ();
      cloog_domain_polyhedron_set (domain, polyhedron);

      return domain;
    }
}


/**
 * cloog_domain_matrix2domain function:
 * Given a matrix of constraints (matrix), this function constructs and returns
 * the corresponding domain (i.e. the CloogDomain structure including the
 * polyhedron with its double representation: constraint matrix and the set of
 * rays).
 */
static CloogDomain *
cloog_domain_matrix2domain (CloogMatrix * matrix)
{
  return (cloog_domain_alloc (Constraints2Polyhedron (matrix, MAX_RAYS)));
}


static inline Polyhedron *
cloog_domain_polyhedron (CloogDomain * domain)
{
  return domain->_polyhedron;
}

/**
 * cloog_domain_domain2matrix function:
 * Given a polyhedron (in domain), this function returns its corresponding
 * matrix of constraints.
 */
static CloogMatrix *
cloog_domain_domain2matrix (CloogDomain * domain)
{
  return Polyhedron2Constraints (cloog_domain_polyhedron (domain));
}

/* In the matrix representation an equality has a 0 in the first
   column.  When the value of the first column is 1, the row
   represents an inequality.  */

static inline int
cloog_matrix_row_is_eq_p (CloogMatrix *matrix, int row)
{
  return value_zero_p (matrix->p[row][0]);
}

static ppl_Polyhedron_t
cloog_translate_constraint_matrix (CloogMatrix *matrix)
{
  int i, j;
  ppl_Polyhedron_t res;
  ppl_Constraint_t cstr;
  ppl_Linear_Expression_t expr;
  ppl_Coefficient_t coef;
  ppl_dimension_type dim = matrix->NbColumns - 2;

  ppl_new_Coefficient (&coef);
  ppl_new_NNC_Polyhedron_from_dimension (&res, dim);

  for (i = 0; i < matrix->NbRows; i++)
    {
      ppl_new_Linear_Expression_with_dimension (&expr, dim);

      for (j = 1; j < matrix->NbColumns - 1; j++)
        {
          ppl_assign_Coefficient_from_mpz_t (coef, matrix->p[i][j]);
          ppl_Linear_Expression_add_to_coefficient (expr, j - 1, coef);
        }

      ppl_assign_Coefficient_from_mpz_t 
        (coef, matrix->p[i][matrix->NbColumns - 1]);
      ppl_Linear_Expression_add_to_inhomogeneous (expr, coef);

      if (cloog_matrix_row_is_eq_p (matrix, i))
        ppl_new_Constraint (&cstr, expr, PPL_CONSTRAINT_TYPE_EQUAL);
      else
        ppl_new_Constraint (&cstr, expr, PPL_CONSTRAINT_TYPE_GREATER_THAN_OR_EQUAL);

      ppl_Polyhedron_add_constraint (res, cstr);
    }

  if (cloog_check_polyhedral_ops)
    ppl_Polyhedron_OK (res);

  return res;
}

static CloogDomain *
cloog_translate_ppl_polyhedron (ppl_Polyhedron_t pol)
{
  CloogDomain *res;
  CloogMatrix *matrix ;
  ppl_dimension_type dim;
  ppl_const_Constraint_System_t pcs;
  ppl_Constraint_System_const_iterator_t cit, end;
  int row;

  ppl_Polyhedron_constraints (pol, &pcs);
  ppl_new_Constraint_System_const_iterator (&cit);
  ppl_new_Constraint_System_const_iterator (&end);

  for (row = 0, ppl_Constraint_System_begin (pcs, cit), ppl_Constraint_System_end (pcs, end);
       !ppl_Constraint_System_const_iterator_equal_test (cit, end);
       ppl_Constraint_System_const_iterator_increment (cit), row++);

  ppl_Polyhedron_space_dimension (pol, &dim);
  matrix = cloog_matrix_alloc (row, dim + 2);

  for (row = 0, ppl_Constraint_System_begin (pcs, cit), ppl_Constraint_System_end (pcs, end);
       !ppl_Constraint_System_const_iterator_equal_test (cit, end);
       ppl_Constraint_System_const_iterator_increment (cit), row++)
    {
      ppl_const_Constraint_t pc;
      ppl_Coefficient_t coef;
      ppl_dimension_type col;
      Value val;
      int neg;

      value_init (val);
      ppl_new_Coefficient (&coef);
      ppl_Constraint_System_const_iterator_dereference (cit, &pc);

      neg = (ppl_Constraint_type (pc) == PPL_CONSTRAINT_TYPE_LESS_THAN
             || ppl_Constraint_type (pc) == PPL_CONSTRAINT_TYPE_LESS_THAN_OR_EQUAL) ? 1 : 0;

      for (col = 0; col < dim; col++)
        {
          ppl_Constraint_coefficient (pc, col, coef);
          ppl_Coefficient_to_mpz_t (coef, val);

          if (neg)
            value_oppose (val, val);

          value_assign (matrix->p[row][col+1], val);
        }

      ppl_Constraint_inhomogeneous_term (pc, coef);
      ppl_Coefficient_to_mpz_t (coef, val);
      value_assign (matrix->p[row][dim + 1], val);

      switch (ppl_Constraint_type (pc))
        {
        case PPL_CONSTRAINT_TYPE_EQUAL:
          value_set_si (matrix->p[row][0], 0);
          break;

        case PPL_CONSTRAINT_TYPE_LESS_THAN:
        case PPL_CONSTRAINT_TYPE_GREATER_THAN:
          value_decrement (matrix->p[row][dim + 1], matrix->p[row][dim + 1]);
          value_set_si (matrix->p[row][0], 1);
          break;

        case PPL_CONSTRAINT_TYPE_LESS_THAN_OR_EQUAL:
        case PPL_CONSTRAINT_TYPE_GREATER_THAN_OR_EQUAL:
          value_set_si (matrix->p[row][0], 1);
          break;

        default:
          fprintf (stderr, "PPL_CONSTRAINT_TYPE_%d not implemented yet\n",
                   ppl_Constraint_type (pc));
          exit (1);
        }
    }

  res = cloog_domain_matrix2domain (matrix);
  return res;
}

static inline int
cloog_domain_references (CloogDomain * d)
{
  return d->_references;
}

/**
 * cloog_domain_print function:
 * This function prints the content of a CloogDomain structure (domain) into
 * a file (foo, possibly stdout).
 */
void
cloog_domain_print (FILE * foo, CloogDomain * domain)
{
  Polyhedron_Print (foo, P_VALUE_FMT, cloog_domain_polyhedron (domain));
  fprintf (foo, "Number of active references: %d\n",
           cloog_domain_references (domain));
}

/**
 * cloog_domain_free function:
 * This function frees the allocated memory for a CloogDomain structure
 * (domain). It decrements the number of active references to this structure,
 * if there are no more references on the structure, it frees it (with the
 * included list of polyhedra).
 */
void
cloog_domain_free (CloogDomain * domain)
{
  if (domain != NULL)
    {
      cloog_domain_set_references (domain,
                                   cloog_domain_references (domain) - 1);

      if (cloog_domain_references (domain) == 0)
        {
          if (cloog_domain_polyhedron (domain) != NULL)
            Domain_Free (cloog_domain_polyhedron (domain));

          free (domain);
        }
    }
}


/**
 * cloog_domain_copy function:
 * This function returns a copy of a CloogDomain structure (domain). To save
 * memory this is not a memory copy but we increment a counter of active
 * references inside the structure, then return a pointer to that structure.
 */
CloogDomain *
cloog_domain_copy (CloogDomain * domain)
{
  cloog_domain_set_references (domain, cloog_domain_references (domain) + 1);
  return domain;
}


/**
 * cloog_domain_image function:
 * This function returns a CloogDomain structure such that the included
 * polyhedral domain is computed from the former one into another
 * domain according to a given affine mapping function (mapping). 
 */
static CloogDomain *
cloog_domain_image (CloogDomain * domain, CloogMatrix * mapping)
{
  return (cloog_domain_alloc
          (DomainImage
           (cloog_domain_polyhedron (domain), mapping, MAX_RAYS)));
}


/**
 * cloog_domain_preimage function:
 * Given a polyhedral domain (polyhedron) inside a CloogDomain structure and a
 * mapping function (mapping), this function returns a new CloogDomain structure
 * with a polyhedral domain which when transformed by mapping function (mapping)
 * gives (polyhedron).
 */
static CloogDomain *
cloog_domain_preimage (CloogDomain * domain, CloogMatrix * mapping)
{
  return (cloog_domain_alloc
          (DomainPreimage
           (cloog_domain_polyhedron (domain), mapping, MAX_RAYS)));
}


/**
 * cloog_domain_convex function:
 * Given a polyhedral domain (polyhedron), this function concatenates the lists
 * of rays and lines of the two (or more) polyhedra in the domain into one
 * combined list, and  find the set of constraints which tightly bound all of
 * those objects. It returns the corresponding polyhedron.
 */
CloogDomain *
cloog_domain_convex (CloogDomain * domain)
{
  return (cloog_domain_alloc
          (DomainConvex (cloog_domain_polyhedron (domain), MAX_RAYS)));
}

static inline Polyhedron *
cloog_polyhedron_next (Polyhedron * p)
{
  return p->next;
}

static inline void
cloog_polyhedron_set_next (Polyhedron * p, Polyhedron * n)
{
  p->next = n;
}

static inline Polyhedron *
cloog_domain_polyhedron_next (CloogDomain * domain)
{
  return cloog_polyhedron_next (cloog_domain_polyhedron (domain));
}

static inline void
cloog_domain_polyhedron_set_next (CloogDomain * d, Polyhedron * n)
{
  cloog_polyhedron_set_next (cloog_domain_polyhedron (d), n);
}

static inline unsigned
cloog_polyhedron_nbc (Polyhedron * p)
{
  return p->NbConstraints;
}

static inline int
cloog_domain_nbconstraints (CloogDomain * domain)
{
  return cloog_domain_polyhedron (domain)->NbConstraints;
}

static inline unsigned
cloog_polyhedron_nbeq (Polyhedron * p)
{
  return p->NbEq;
}

static inline unsigned
cloog_domain_nbeq (CloogDomain * d)
{
  return cloog_polyhedron_nbeq (cloog_domain_polyhedron (d));
}

static inline unsigned
cloog_polyhedron_dim (Polyhedron * p)
{
  return p->Dimension;
}


int
cloog_domain_isconvex (CloogDomain * domain)
{
  return !cloog_domain_polyhedron_next (domain);
}

unsigned
cloog_domain_dim (CloogDomain * d)
{
  return cloog_polyhedron_dim (cloog_domain_polyhedron (d));
}

/**
 * cloog_domain_simple_convex:
 * Given a list (union) of polyhedra, this function returns a "simple"
 * convex hull of this union.  In particular, the constraints of the
 * the returned polyhedron consist of (parametric) lower and upper
 * bounds on individual variables and constraints that appear in the
 * original polyhedra.
 *
 * nb_par is the number of parameters of the domain.
 */
CloogDomain *
cloog_domain_simple_convex (CloogDomain * domain, int nb_par)
{
  fprintf (stderr, "cloog_domain_simple_convex is not implemented yet.\n");
  exit (1);
}


/**
 * cloog_domain_simplify function:
 * Given two polyhedral domains (pol1) and (pol2) inside two CloogDomain
 * structures, this function finds the largest domain set (or the smallest list
 * of non-redundant constraints), that when intersected with polyhedral
 * domain (pol2) equals (Pol1)intersect(Pol2). The output is a new CloogDomain
 * structure with a polyhedral domain with the "redundant" constraints removed.
 * NB: this function do not work as expected with unions of polyhedra...
 */
CloogDomain *
cloog_domain_simplify (CloogDomain * dom1, CloogDomain * dom2)
{
  CloogMatrix *M, *M2;
  CloogDomain *dom;
  Polyhedron *P = cloog_domain_polyhedron (dom1);

  /* DomainSimplify doesn't remove all redundant equalities,
   * so we remove them here first in case both dom1 and dom2
   * are single polyhedra (i.e., not unions of polyhedra).
   */
  if (cloog_domain_isconvex (dom1)
      && cloog_domain_isconvex (dom2)
      && cloog_polyhedron_nbeq (P) && cloog_domain_nbeq (dom2))
    {
      int i, row;
      int rows = cloog_polyhedron_nbeq (P) + cloog_domain_nbeq (dom2);
      int cols = cloog_polyhedron_dim (P) + 2;
      int rank;
      M = cloog_matrix_alloc (rows, cols);
      M2 = cloog_matrix_alloc (cloog_polyhedron_nbc (P), cols);
      Vector_Copy (cloog_domain_polyhedron (dom2)->Constraint[0],
                   M->p[0], cloog_domain_nbeq (dom2) * cols);
      rank = cloog_domain_nbeq (dom2);
      row = 0;
      for (i = 0; i < cloog_polyhedron_nbeq (P); ++i)
        {
          Vector_Copy (P->Constraint[i], M->p[rank], cols);
          if (Gauss (M, rank + 1, cols - 1) > rank)
            {
              Vector_Copy (P->Constraint[i], M2->p[row++], cols);
              rank++;
            }
        }
      if (row < cloog_polyhedron_nbeq (P))
        {
          Vector_Copy (P->Constraint[cloog_polyhedron_nbeq (P)],
                       M2->p[row],
                       (cloog_polyhedron_nbc (P) -
                        cloog_polyhedron_nbeq (P)) * cols);
          P = Constraints2Polyhedron (M2, MAX_RAYS);
        }
      cloog_matrix_free (M2);
      cloog_matrix_free (M);
    }
  dom =
    cloog_domain_alloc (DomainSimplify
                        (P, cloog_domain_polyhedron (dom2), MAX_RAYS));
  if (P != cloog_domain_polyhedron (dom1))
    Polyhedron_Free (P);
  return dom;
}


/**
 * cloog_domain_union function:
 * This function returns a new CloogDomain structure including a polyhedral
 * domain which is the union of two polyhedral domains (pol1) U (pol2) inside
 * two CloogDomain structures.
 */
CloogDomain *
cloog_domain_union (CloogDomain * dom1, CloogDomain * dom2)
{
  if (!cloog_domain_polyhedron (dom1))
    return cloog_domain_alloc (cloog_domain_polyhedron (dom2));

  if (!cloog_domain_polyhedron (dom2))
    return cloog_domain_alloc (cloog_domain_polyhedron (dom1));

  return (cloog_domain_alloc (DomainUnion (cloog_domain_polyhedron (dom1),
                                           cloog_domain_polyhedron (dom2),
                                           MAX_RAYS)));
}

/**
 * cloog_domain_intersection function:
 * This function returns a new CloogDomain structure including a polyhedral
 * domain which is the intersection of two polyhedral domains (pol1)inter(pol2)
 * inside two CloogDomain structures.
 */
CloogDomain *
cloog_domain_intersection (CloogDomain * dom1, CloogDomain * dom2)
{
  CloogDomain *res;
  Polyhedron *p1, *p2;
  ppl_Polyhedron_t ppl1, ppl2;

  res = cloog_domain_malloc ();

  for (p1 = cloog_domain_polyhedron (dom1); p1; p1 = p1->next)
    {
        ppl1 = cloog_translate_constraint_matrix (Polyhedron2Constraints (p1));

        for (p2 = cloog_domain_polyhedron (dom2); p2; p2 = p2->next)
          {
            ppl2 = cloog_translate_constraint_matrix (Polyhedron2Constraints (p2));
            ppl_Polyhedron_intersection_assign (ppl2, ppl1);

            res = cloog_domain_union (res, cloog_translate_ppl_polyhedron (ppl2));
          }
    }

  if (cloog_check_polyhedral_ops)
    {
      CloogDomain *ppl = res;
      CloogDomain *polylib = cloog_domain_alloc
        (DomainIntersection (cloog_domain_polyhedron (dom1),
                             cloog_domain_polyhedron (dom2),
                             MAX_RAYS));

      /* Cannot use cloog_domain_lazy_equal (polylib, ppl) here as
         this function is too dumb: it does not detect permutations of
         constraints.  */
      if (!cloog_domain_isempty (cloog_domain_difference (polylib, ppl))
          && !cloog_domain_isempty (cloog_domain_difference (ppl, polylib)))
        {
          fprintf (stderr, "((\n");
          cloog_domain_print (stderr, ppl);
          fprintf (stderr, ")(\n");
          cloog_domain_print (stderr, polylib);
          fprintf (stderr, "))\n");
          exit (1);
        }

      if (cloog_return_ppl_result)
        return ppl;
      else
        return polylib;
    }

  if (cloog_return_ppl_result)
    return res;
  else
    return (cloog_domain_alloc
            (DomainIntersection
             (cloog_domain_polyhedron (dom1), cloog_domain_polyhedron (dom2),
              MAX_RAYS)));
}


/**
 * cloog_domain_difference function:
 * This function returns a new CloogDomain structure including a polyhedral
 * domain which is the difference of two polyhedral domains domain \ minus
 * inside two CloogDomain structures.
 * - November 8th 2001: first version.
 */
CloogDomain *
cloog_domain_difference (CloogDomain * domain, CloogDomain * minus)
{
  if (cloog_domain_isempty (minus))
    return (cloog_domain_copy (domain));
  else
    return (cloog_domain_alloc
            (DomainDifference
             (cloog_domain_polyhedron (domain),
              cloog_domain_polyhedron (minus), MAX_RAYS)));
}


/**
 * cloog_domain_addconstraints function :
 * This function adds source's polyhedron constraints to target polyhedron: for
 * each element of the polyhedron inside 'target' (i.e. element of the union
 * of polyhedra) it adds the constraints of the corresponding element in
 * 'source'.
 * - August 10th 2002: first version.
 * Nota bene for future : it is possible that source and target don't have the
 * same number of elements (try iftest2 without non-shared constraint
 * elimination in cloog_loop_separate !). This function is yet another part
 * of the DomainSimplify patching problem...
 */
CloogDomain *
cloog_domain_addconstraints (domain_source, domain_target)
     CloogDomain *domain_source, *domain_target;
{
  unsigned nb_constraint;
  Value *constraints;
  Polyhedron *source, *target, *new, *next, *last;

  source = cloog_domain_polyhedron (domain_source);
  target = cloog_domain_polyhedron (domain_target);

  constraints = source->p_Init;
  nb_constraint = cloog_polyhedron_nbc (source);
  source = cloog_polyhedron_next (source);
  new = AddConstraints (constraints, nb_constraint, target, MAX_RAYS);
  last = new;
  next = cloog_polyhedron_next (target);

  while (next != NULL)
    {                           /* BUG !!! This is actually a bug. I don't know yet how to cleanly avoid
                                 * the situation where source and target do not have the same number of
                                 * elements. So this 'if' is an awful trick, waiting for better.
                                 */
      if (source != NULL)
        {
          constraints = source->p_Init;
          nb_constraint = cloog_polyhedron_nbc (source);
          source = cloog_polyhedron_next (source);
        }
      cloog_polyhedron_set_next (last,
                                 AddConstraints (constraints, nb_constraint,
                                                 next, MAX_RAYS));
      last = cloog_polyhedron_next (last);
      next = cloog_polyhedron_next (next);
    }

  return (cloog_domain_alloc (new));
}


/**
 * cloog_domain_sort function:
 * This function topologically sorts (nb_pols) polyhedra. Here (pols) is a an
 * array of pointers to polyhedra, (nb_pols) is the number of polyhedra,
 * (level) is the level to consider for partial ordering (nb_par) is the
 * parameter space dimension, (permut) if not NULL, is an array of (nb_pols)
 * integers that contains a permutation specification after call in order to
 * apply the topological sorting. 
 */
void
cloog_domain_sort (doms, nb_pols, level, nb_par, permut)
     CloogDomain **doms;
     unsigned nb_pols, level, nb_par;
     int *permut;
{
  int *time, i;
  Polyhedron **pols =
    (Polyhedron **) malloc (nb_pols * sizeof (Polyhedron *));

  for (i = 0; i < nb_pols; i++)
    pols[i] = cloog_domain_polyhedron (doms[i]);

  /* time is an array of (nb_pols) integers to store logical time values. We
   * do not use it, but it is compulsory for PolyhedronTSort.
   */
  time = (int *) malloc (nb_pols * sizeof (int));

  /* PolyhedronTSort will fill up permut (and time). */
  PolyhedronTSort (pols, nb_pols, level, nb_par, time, permut, MAX_RAYS);

  free (pols);
  free (time);
}


/**
 * cloog_domain_empty function:
 * This function allocates the memory space for a CloogDomain structure and
 * sets its polyhedron to an empty polyhedron with 'dimension' dimensions.
 * Then it returns a pointer to the allocated space.
 * - June 10th 2005: first version.
 */
CloogDomain *
cloog_domain_empty (int dimension)
{
  return (cloog_domain_alloc (Empty_Polyhedron (dimension)));
}


/******************************************************************************
 *                          Structure display function                        *
 ******************************************************************************/


/**
 * cloog_domain_print_structure :
 * this function is a more human-friendly way to display the CloogDomain data
 * structure, it only shows the constraint system and includes an indentation
 * level (level) in order to work with others print_structure functions.
 * Written by Olivier Chorier, Luc Marchaud, Pierre Martin and Romain Tartiere.
 * - April 24th 2005: Initial version.
 * - May   26th 2005: Memory leak hunt.
 * - June  16th 2005: (Ced) Integration in domain.c.
 */
void
cloog_domain_print_structure (FILE * file, CloogDomain * domain, int level)
{
  int i;
  CloogMatrix *matrix;

  /* Go to the right level. */
  for (i = 0; i < level; i++)
    fprintf (file, "|\t");

  if (domain != NULL)
    {
      fprintf (file, "+-- CloogDomain\n");

      /* Print the matrix. */
      matrix = cloog_domain_domain2matrix (domain);
      cloog_matrix_print_structure (file, matrix, level);
      cloog_matrix_free (matrix);

      /* A blank line. */
      for (i = 0; i < level + 1; i++)
        fprintf (file, "|\t");
      fprintf (file, "\n");
    }
  else
    fprintf (file, "+-- Null CloogDomain\n");

}


/**
 * cloog_domain_list_print function:
 * This function prints the content of a CloogDomainList structure into a
 * file (foo, possibly stdout).
 * - November 6th 2001: first version.
 */
void
cloog_domain_list_print (FILE * foo, CloogDomainList * list)
{
  while (list != NULL)
    {
      cloog_domain_print (foo, cloog_domain (list));
      list = cloog_next_domain (list);
    }
}


/******************************************************************************
 *                         Memory deallocation function                       *
 ******************************************************************************/


/**
 * cloog_domain_list_free function:
 * This function frees the allocated memory for a CloogDomainList structure.
 * - November 6th 2001: first version.
 */
void
cloog_domain_list_free (CloogDomainList * list)
{
  CloogDomainList *temp;

  while (list != NULL)
    {
      temp = cloog_next_domain (list);
      cloog_domain_free (cloog_domain (list));
      free (list);
      list = temp;
    }
}


/******************************************************************************
 *                               Reading function                             *
 ******************************************************************************/


/**
 * cloog_domain_read function:
 * Adaptation from the PolyLib. This function reads a matrix into a file (foo,
 * posibly stdin) and returns a pointer to a polyhedron containing the read
 * information. 
 * - October 18th 2001: first version.
 */
CloogDomain *
cloog_domain_read (FILE * foo)
{
  CloogMatrix *matrix;
  CloogDomain *domain;

  matrix = cloog_matrix_read (foo);
  domain = cloog_domain_matrix2domain (matrix);
  cloog_matrix_free (matrix);

  return (domain);
}


/**
 * cloog_domain_union_read function:
 * This function reads a union of polyhedra into a file (foo, posibly stdin) and
 * returns a pointer to a Polyhedron containing the read information. 
 * - September 9th 2002: first version.
 * - October  29th 2005: (debug) removal of a leak counting "correction" that
 *                       was just false since ages.
 */
CloogDomain *
cloog_domain_union_read (FILE * foo)
{
  int i, nb_components;
  char s[MAX_STRING];
  CloogDomain *domain, *temp, *old;

  /* domain reading: nb_components (constraint matrices). */
  while (fgets (s, MAX_STRING, foo) == 0);
  while ((*s == '#' || *s == '\n') || (sscanf (s, " %d", &nb_components) < 1))
    fgets (s, MAX_STRING, foo);

  if (nb_components > 0)
    {                           /* 1. first part of the polyhedra union, */
      domain = cloog_domain_read (foo);
      /* 2. and the nexts. */
      for (i = 1; i < nb_components; i++)
        {                       /* Leak counting is OK since next allocated domain is freed here. */
          temp = cloog_domain_read (foo);
          old = domain;
          domain = cloog_domain_union (temp, old);
          cloog_domain_free (temp);
          cloog_domain_free (old);
        }
      return domain;
    }
  else
    return NULL;
}


/**
 * cloog_domain_list_read function:
 * This function reads a list of polyhedra into a file (foo, posibly stdin) and
 * returns a pointer to a CloogDomainList containing the read information. 
 * - November 6th 2001: first version.
 */
CloogDomainList *
cloog_domain_list_read (FILE * foo)
{
  int i, nb_pols;
  char s[MAX_STRING];
  CloogDomainList *list, *now, *next;


  /* We read first the number of polyhedra in the list. */
  while (fgets (s, MAX_STRING, foo) == 0);
  while ((*s == '#' || *s == '\n') || (sscanf (s, " %d", &nb_pols) < 1))
    fgets (s, MAX_STRING, foo);

  /* Then we read the polyhedra. */
  list = NULL;
  if (nb_pols > 0)
    {
      list = (CloogDomainList *) malloc (sizeof (CloogDomainList));
      cloog_set_domain (list, cloog_domain_read (foo));
      cloog_set_next_domain (list, NULL);
      now = list;
      for (i = 1; i < nb_pols; i++)
        {
          next = (CloogDomainList *) malloc (sizeof (CloogDomainList));
          cloog_set_domain (next, cloog_domain_read (foo));
          cloog_set_next_domain (next, NULL);
          cloog_set_next_domain (now, next);
          now = cloog_next_domain (now);
        }
    }
  return (list);
}


/******************************************************************************
 *                            Processing functions                            *
 ******************************************************************************/

/**
 * cloog_domain_isempty function:
 * This function returns 1 if the polyhedron given as input is empty, 0
 * otherwise.
 * - October 28th 2001: first version.
 */
int
cloog_domain_isempty (CloogDomain * domain)
{
  if (cloog_domain_polyhedron (domain) == NULL)
    return 1;

  if (cloog_domain_polyhedron_next (domain))
    return (0);

  return ((cloog_domain_dim (domain) < cloog_domain_nbeq (domain)) ? 1 : 0);
}


/**
 * cloog_domain_project function:
 * From Quillere's LoopGen 0.4. This function returns the projection of
 * (domain) on the (level) first dimensions (i.e. outer loops). It returns a
 * pointer to the projected Polyhedron.
 * - nb_par is the number of parameters.
 **
 * - October 27th 2001: first version.
 * - June 21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                   CLooG 0.12.1).
 */
CloogDomain *
cloog_domain_project (CloogDomain * domain, int level, int nb_par)
{
  int row, column, nb_rows, nb_columns, difference;
  CloogDomain *projected_domain;
  CloogMatrix *matrix;

  nb_rows = level + nb_par + 1;
  nb_columns = cloog_domain_dim (domain) + 1;
  difference = nb_columns - nb_rows;

  if (difference == 0)
    return (cloog_domain_copy (domain));

  matrix = cloog_matrix_alloc (nb_rows, nb_columns);

  for (row = 0; row < level; row++)
    for (column = 0; column < nb_columns; column++)
      value_set_si (matrix->p[row][column], (row == column ? 1 : 0));

  for (; row < nb_rows; row++)
    for (column = 0; column < nb_columns; column++)
      value_set_si (matrix->p[row][column],
                    (row + difference == column ? 1 : 0));

  projected_domain = cloog_domain_image (domain, matrix);
  cloog_matrix_free (matrix);

  return (projected_domain);
}

/**
 * cloog_domain_extend function:
 * From Quillere's LoopGen 0.4. This function returns the (domain) given as
 * input with (dim)+(nb_par) dimensions. The new dimensions are added before
 * the (nb_par) parameters. This function does not free (domain), and returns
 * a new polyhedron.
 * - nb_par is the number of parameters.
 **
 * - October 27th 2001: first version.
 * - June 21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                 CLooG 0.12.1).
 */
CloogDomain *
cloog_domain_extend (CloogDomain * domain, int dim, int nb_par)
{
  int row, column, nb_rows, nb_columns, difference;
  CloogDomain *extended_domain;
  CloogMatrix *matrix;

  nb_rows = 1 + cloog_domain_dim (domain);
  nb_columns = dim + nb_par + 1;
  difference = nb_columns - nb_rows;

  if (difference == 0)
    return (cloog_domain_copy (domain));

  matrix = cloog_matrix_alloc (nb_rows, nb_columns);

  for (row = 0; row < cloog_domain_dim (domain) - nb_par; row++)
    for (column = 0; column < nb_columns; column++)
      value_set_si (matrix->p[row][column], (row == column ? 1 : 0));

  for (; row <= cloog_domain_dim (domain); row++)
    for (column = 0; column < nb_columns; column++)
      value_set_si (matrix->p[row][column],
                    (row + difference == column ? 1 : 0));

  extended_domain = cloog_domain_preimage (domain, matrix);
  cloog_matrix_free (matrix);

  return (extended_domain);
}


/**
 * cloog_domain_never_integral function:
 * For us, an equality like 3*i -4 = 0 is always false since 4%3 != 0. This
 * function returns a boolean set to 1 if there is this kind of 'never true'
 * constraint inside a polyhedron, 0 otherwise.
 * - domain is the polyhedron to check,
 **
 * - November 28th 2001: first version. 
 * - June 26th 2003: for iterators, more 'never true' constraints are found
 *                   (compare cholesky2 and vivien with a previous version),
 *                   checking for the parameters created (compare using vivien).
 * - June 28th 2003: Previously in loop.c and called
 *                   cloog_loop_simplify_nevertrue, now here !
 * - June 21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                   CLooG 0.12.1).
 * - October 14th 2005: Complete rewriting, not faster but code quite shorter.
 */
int
cloog_domain_never_integral (CloogDomain * domain)
{
  int i, dimension;
  Value gcd, modulo;
  Polyhedron *polyhedron;

  if ((domain == NULL) || (cloog_domain_polyhedron (domain) == NULL))
    return 1;

  value_init_c (gcd);
  value_init_c (modulo);
  polyhedron = cloog_domain_polyhedron (domain);
  dimension = cloog_domain_dim (domain) + 2;

  /* For each constraint... */
  for (i = 0; i < cloog_polyhedron_nbc (polyhedron); i++)
    {                           /* If we have an equality and the scalar part is not zero... */
      if (value_zero_p (polyhedron->Constraint[i][0]) &&
          value_notzero_p (polyhedron->Constraint[i][dimension - 1]))
        {                       /* Then we check whether the scalar can be divided by the gcd of the
                                 * unknown vector (including iterators and parameters) or not. If not,
                                 * there is no integer point in the polyhedron and we return 1.
                                 */
          Vector_Gcd (&(polyhedron->Constraint[i][1]), dimension - 2, &gcd);
          value_modulus (modulo,
                         polyhedron->Constraint[i][dimension - 1],
                         gcd);

          if (value_notzero_p (modulo))
            {
              value_clear_c (gcd);
              value_clear_c (modulo);
              return 1;
            }
        }
    }

  value_clear_c (gcd);
  value_clear_c (modulo);
  return (0);
}


/**
 * cloog_domain_stride function:
 * This function finds the stride imposed to unknown with the column number
 * 'strided_level' in order to be integral. For instance, if we have a
 * constraint like -i - 2j + 2k = 0, and we consider k, then k can be integral
 * only if (i + 2j)%2 = 0. Then only if i%2 = 0. Then k imposes a stride 2 to
 * the unknown i. The function returns the imposed stride in a parameter field.
 * - domain is the set of constraint we have to consider,
 * - strided_level is the column number of the unknown for which a stride have
 *   to be found,
 * - looking_level is the column number of the unknown that impose a stride to
 *   the first unknown.
 * - stride is the stride that is returned back as a function parameter. 
 * - offset is the value of the constant c if the condition is of the shape
 *   (i + c)%s = 0, s being the stride.
 **
 * - June 28th 2003: first version.
 * - July 14th 2003: can now look for multiple striding constraints and returns
 *                   the GCD of the strides and the common offset.
 * - June 21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                   CLooG 0.12.1).
 */
void
cloog_domain_stride (domain, strided_level, nb_par, stride, offset)
     CloogDomain *domain;
     int strided_level, nb_par;
     Value *stride, *offset;
{
  int i, dimension;
  Polyhedron *polyhedron;
  int n_col, n_row, rank;
  CloogMatrix *M;
  Matrix *U;
  Vector *V;

  polyhedron = cloog_domain_polyhedron (domain);
  dimension = cloog_domain_dim (domain);

  /* Look at all equalities involving strided_level and the inner
   * iterators.  We can ignore the outer iterators and the parameters
   * here because the lower bound on strided_level is assumed to
   * be a constant.
   */
  n_col = (1 + dimension - nb_par) - strided_level;
  for (i = 0, n_row = 0; i < cloog_polyhedron_nbeq (polyhedron); i++)
    if (First_Non_Zero
        (polyhedron->Constraint[i] + strided_level, n_col) != -1)
      ++n_row;

  M = cloog_matrix_alloc (n_row + 1, n_col + 1);
  for (i = 0, n_row = 0; i < cloog_polyhedron_nbeq (polyhedron); i++)
    {
      if (First_Non_Zero
          (polyhedron->Constraint[i] + strided_level, n_col) == -1)
        continue;
      Vector_Copy (polyhedron->Constraint[i] + strided_level,
                   M->p[n_row], n_col);
      value_assign (M->p[n_row][n_col],
                    polyhedron->Constraint[i][1 + dimension]);
      ++n_row;
    }
  value_set_si (M->p[n_row][n_col], 1);

  /* Then look at the general solution to the above equalities. */
  rank = SolveDiophantine (M, &U, &V);
  cloog_matrix_free (M);

  if (rank == -1)
    {
      /* There is no solution, so the body of this loop will
       * never execute.  We just leave the constraints alone here so
       * that they will ensure the body will not be executed.
       * We should probably propagate this information up so that
       * the loop can be removed entirely.
       */
      value_set_si (*offset, 0);
      value_set_si (*stride, 1);
    }
  else
    {
      /* Compute the gcd of the coefficients defining strided_level. */
      Vector_Gcd (U->p[0], U->NbColumns, stride);
      value_oppose (*offset, V->p[0]);
      value_pmodulus (*offset, *offset, *stride);
    }
  Matrix_Free (U);
  Vector_Free (V);

  return;
}


/**
 * cloog_domain_integral_lowerbound function:
 * This function returns 1 if the lower bound of an iterator (such as its
 * column rank in the constraint set 'domain' is 'level') is integral,
 * 0 otherwise. If the lower bound is actually integral, the function fills
 * the 'lower' field with the lower bound value.
 * - June 29th 2003: first version.
 * - June 21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                   CLooG 0.12.1).
 */
int
cloog_domain_integral_lowerbound (domain, level, lower)
     CloogDomain *domain;
     int level;
     Value *lower;
{
  int i, first_lower = 1, dimension, lower_constraint = -1;
  Value iterator, constant, tmp;
  Polyhedron *polyhedron;

  polyhedron = cloog_domain_polyhedron (domain);
  dimension = cloog_domain_dim (domain);

  /* We want one and only one lower bound (e.g. no equality, no maximum
   * calculation...).
   */
  for (i = 0; i < cloog_polyhedron_nbc (polyhedron); i++)
    if (value_zero_p (polyhedron->Constraint[i][0])
        && value_notzero_p (polyhedron->Constraint[i][level]))
      return 0;

  for (i = 0; i < cloog_polyhedron_nbc (polyhedron); i++)
    if (value_pos_p (polyhedron->Constraint[i][level]))
      {
        if (first_lower)
          {
            first_lower = 0;
            lower_constraint = i;
          }
        else
          return 0;
      }

  if (first_lower)
    return 0;

  /* We want an integral lower bound: no other non-zero entry except the
   * iterator coefficient and the constant.
   */
  for (i = 1; i < level; i++)
    if (value_notzero_p
        (polyhedron->Constraint[lower_constraint][i]))
      return 0;

  for (i = level + 1; i <= cloog_polyhedron_dim (polyhedron); i++)
    if (value_notzero_p
        (polyhedron->Constraint[lower_constraint][i]))
      return 0;

  value_init_c (iterator);
  value_init_c (constant);
  value_init_c (tmp);

  /* If all is passed, then find the lower bound and return 1. */
  value_assign (iterator,
                polyhedron->Constraint[lower_constraint][level]);
  value_oppose (constant,
                polyhedron->Constraint[lower_constraint][dimension + 1]);

  value_modulus (tmp, constant, iterator);
  value_division (*lower, constant, iterator);

  if (!(value_zero_p (tmp) || value_neg_p (constant)))
    value_increment (*lower, *lower);

  value_clear_c (iterator);
  value_clear_c (constant);
  value_clear_c (tmp);

  return 1;
}


/**
 * cloog_domain_lowerbound_update function:
 * This function updates the integral lower bound of an iterator (such as its
 * column rank in the constraint set 'domain' is 'level') into  'lower'.
 * - Jun  29th 2003: first version.
 * - June 21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                   CLooG 0.12.1).
 */
void
cloog_domain_lowerbound_update (domain, level, lower)
     CloogDomain *domain;
     int level;
     Value lower;
{
  int i;
  Polyhedron *polyhedron;

  polyhedron = cloog_domain_polyhedron (domain);

  /* There is only one lower bound, the first one is the good one. */
  for (i = 0; i < cloog_polyhedron_nbc (polyhedron); i++)
    if (value_pos_p (polyhedron->Constraint[i][level]))
      {
        value_set_si (polyhedron->Constraint[i][level], 1);
        value_oppose (polyhedron->Constraint[i][cloog_polyhedron_dim (polyhedron) + 1], lower);
        break;
      }
}


/**
 * cloog_domain_lazy_equal function:
 * This function returns 1 if the domains given as input are the same, 0 if it
 * is unable to decide. This function makes an entry-to-entry comparison between
 * the constraint systems, if all the entries are the same, the domains are
 * obviously the same and it returns 1, at the first difference, it returns 0.
 * This is a very fast way to verify this property. It has been shown (with the
 * CLooG benchmarks) that operations on equal domains are 17% of all the
 * polyhedral computations. For 75% of the actually identical domains, this
 * function answer that they are the same and allow to give immediately the
 * trivial solution instead of calling the heavy general functions of PolyLib.
 * - August 22th 2003: first version.
 * - June 21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                   CLooG 0.12.1).
 */
int
cloog_domain_lazy_equal (CloogDomain * d1, CloogDomain * d2)
{
  int i, nb_elements;
  Polyhedron *p1, *p2;

  p1 = cloog_domain_polyhedron (d1);
  p2 = cloog_domain_polyhedron (d2);

  while ((p1 != NULL) && (p2 != NULL))
    {
      if ((cloog_polyhedron_nbc (p1) != cloog_polyhedron_nbc (p2)) ||
          (cloog_polyhedron_dim (p1) != cloog_polyhedron_dim (p2)))
        return 0;

      nb_elements =
        cloog_polyhedron_nbc (p1) * (cloog_polyhedron_dim (p1) + 2);

      for (i = 0; i < nb_elements; i++)
        if (value_ne (p1->p_Init[i], p2->p_Init[i]))
          return 0;

      p1 = cloog_polyhedron_next (p1);
      p2 = cloog_polyhedron_next (p2);
    }

  if ((p1 != NULL) || (p2 != NULL))
    return 0;

  return 1;
}


/**
 * cloog_domain_lazy_block function:
 * This function returns 1 if the two domains d1 and d2 given as input are the
 * same (possibly except for a dimension equal to a constant where we accept
 * a difference of 1) AND if we are sure that there are no other domain in
 * the code generation problem that may put integral points between those of
 * d1 and d2 (0 otherwise). In fact this function answers the question "can I
 * safely consider the two domains as only one with two statements (a block) ?".
 * This function is lazy: it asks for very standard scattering representation
 * (only one constraint per dimension which is an equality, and the constraints
 * are ordered per dimension depth: the left hand side of the constraint matrix
 * is the identity) and will answer NO at the very first problem.
 * - d1 and d2 are the two domains to check for blocking,
 * - scattering is the linked list of all domains,
 * - scattdims is the total number of scattering dimentions.
 **
 * - April   30th 2005: beginning
 * - June     9th 2005: first working version.
 * - June    10th 2005: debugging.
 * - June    21rd 2005: Adaptation for GMP.
 * - October 16th 2005: (debug) some false blocks have been removed.
 */
int
cloog_domain_lazy_block (d1, d2, scattering, scattdims)
     CloogDomain *d1, *d2;
     CloogDomainList *scattering;
     int scattdims;
{
  int i, j, difference = 0, different_constraint = 0;
  Value date1, date2, date3, temp;
  Polyhedron *p1, *p2, *p3;

  p1 = cloog_domain_polyhedron (d1);
  p2 = cloog_domain_polyhedron (d2);

  /* Some basic checks: we only accept convex domains, with same constraint
   * and dimension numbers.
   */
  if (cloog_polyhedron_next (p1) || cloog_polyhedron_next (p2) ||
      (cloog_polyhedron_nbc (p1) != cloog_polyhedron_nbc (p2)) ||
      (cloog_polyhedron_dim (p1) != cloog_polyhedron_dim (p2)))
    return 0;

  /* There should be only one difference between the two domains, it
   * has to be at the constant level and the difference must be of +1,
   * moreover, after the difference all domain coefficient has to be 0.
   * The matrix shape is:
   *
   * |===========|=====|<- 0 line
   * |===========|=====|
   * |===========|====?|<- different_constraint line (found here)
   * |===========|0000=|
   * |===========|0000=|<- pX->NbConstraints line
   *  ^         ^     ^
   *  |         |     |
   *  |         |     (pX->Dimension + 2) column
   *  |         scattdims column
   *  0 column
   */

  value_init_c (temp);
  for (i = 0; i < cloog_polyhedron_nbc (p1); i++)
    {
      if (difference == 0)
        {                       /* All elements except scalar must be equal. */
          for (j = 0; j < (cloog_polyhedron_dim (p1) + 1); j++)
            if (value_ne (p1->Constraint[i][j],
                          p2->Constraint[i][j]))
              {
                value_clear_c (temp);
                return 0;
              }
          /* The scalar may differ from +1 (now j=(p1->Dimension + 1)). */
          if (value_ne (p1->Constraint[i][j],
                        p2->Constraint[i][j]))
            {
              value_increment (temp, p2->Constraint[i][j]);
              if (value_ne (p1->Constraint[i][j], temp))
                {
                  value_clear_c (temp);
                  return 0;
                }
              else
                {
                  difference = 1;
                  different_constraint = i;
                }
            }
        }
      else
        {                       /* Scattering coefficients must be equal. */
          for (j = 0; j < (scattdims + 1); j++)
            if (value_ne (p1->Constraint[i][j],
                          p2->Constraint[i][j]))
              {
                value_clear_c (temp);
                return 0;
              }

          /* Domain coefficients must be 0. */
          for (; j < (cloog_polyhedron_dim (p1) + 1); j++)
            if (value_notzero_p (p1->Constraint[i][j])
                || value_notzero_p (p2->Constraint[i][j]))
              {
                value_clear_c (temp);
                return 0;
              }

          /* Scalar must be equal. */
          if (value_ne (p1->Constraint[i][j],
                        p2->Constraint[i][j]))
            {
              value_clear_c (temp);
              return 0;
            }
        }
    }
  value_clear_c (temp);

  /* If the domains are exactly the same, this is a block. */
  if (difference == 0)
    return 1;

  /* Now a basic check that the constraint with the difference is an
   * equality of a dimension with a constant.
   */
  for (i = 0; i <= different_constraint; i++)
    if (value_notzero_p (p1->Constraint[different_constraint][i]))
      return 0;

  if (value_notone_p (p1->Constraint[different_constraint][different_constraint + 1]))
    return 0;

  for (i = different_constraint + 2; i < (cloog_polyhedron_dim (p1) + 1); i++)
    if (value_notzero_p (p1->Constraint[different_constraint][i]))
      return 0;

  /* For the moment, d1 and d2 are a block candidate. There remains to check
   * that there is no other domain that may put an integral point between
   * them. In our lazy test we ensure this property by verifying that the
   * constraint matrices have a very strict shape: let us consider that the
   * dimension with the difference is d. Then the first d dimensions are
   * defined in their depth order using equalities (thus the first column begins
   * with d zeroes, there is a d*d identity matrix and a zero-matrix for
   * the remaining simensions). If a domain can put integral points between the
   * domains of the block candidate, this means that the other entries on the
   * first d constraints are equal to those of d1 or d2. Thus we are looking for
   * such a constraint system, if it exists d1 and d2 is considered to not be
   * a block, it is a bock otherwise.
   *
   *  1. Only equalities (for the first different_constraint+1 lines).
   *  |  2. Must be the identity.
   *  |  |    3. Must be zero.
   *  |  |    |     4. Elements are equal, the last one is either date1 or 2.
   *  |  |    |     |
   *  | /-\ /---\ /---\
   * |0|100|00000|=====|<- 0 line
   * |0|010|00000|=====|
   * |0|001|00000|====?|<- different_constraint line
   * |*|***|*****|*****|
   * |*|***|*****|*****|<- pX->NbConstraints line
   *  ^   ^     ^     ^
   *  |   |     |     |
   *  |   |     |     (pX->Dimension + 2) column
   *  |   |     scattdims column
   *  |   different_constraint+1 column
   *  0 column
   */

  /* Step 1 and 2. This is only necessary to check one domain because
   * we checked that they are equal on this part before.
   */
  for (i = 0; i <= different_constraint; i++)
    {
      for (j = 0; j < i + 1; j++)
        if (value_notzero_p (p1->Constraint[i][j]))
          return 0;

      if (value_notone_p (p1->Constraint[i][i + 1]))
        return 0;

      for (j = i + 2; j <= different_constraint + 1; j++)
        if (value_notzero_p (p1->Constraint[i][j]))
          return 0;
    }

  /* Step 3. */
  for (i = 0; i <= different_constraint; i++)
    for (j = different_constraint + 2; j <= scattdims; j++)
      if (value_notzero_p (p1->Constraint[i][j]))
        return 0;

  value_init_c (date1);
  value_init_c (date2);
  value_init_c (date3);

  /* Now we have to check that the two different dates are unique. */
  value_assign (date1, p1->Constraint[different_constraint][cloog_polyhedron_dim (p1) + 1]);
  value_assign (date2, p2->Constraint[different_constraint][cloog_polyhedron_dim (p2) + 1]);

  /* Step 4. We check all domains except d1 and d2 and we look for at least
   * a difference with d1 or d2 on the first different_constraint+1 dimensions.
   */
  while (scattering != NULL)
    {
      if ((cloog_domain (scattering) != d1)
          && (cloog_domain (scattering) != d2))
        {
          p3 = cloog_domain_polyhedron (cloog_domain (scattering));
          value_assign (date3,
                        p3->Constraint[different_constraint][cloog_polyhedron_dim (p3) + 1]);
          difference = 0;

          if (value_ne (date3, date2) && value_ne (date3, date1))
            difference = 1;

          for (i = 0; (i < different_constraint) && (!difference); i++)
            for (j = 0;
                 (j < (cloog_polyhedron_dim (p3) + 2)) && (!difference); j++)
              if (value_ne
                  (p1->Constraint[i][j],
                   p3->Constraint[i][j]))
                difference = 1;

          for (j = 0; (j < (cloog_polyhedron_dim (p3) + 1)) && (!difference);
               j++)
            if (value_ne
                (p1->Constraint[different_constraint][j],
                 p3->Constraint[different_constraint][j]))
              difference = 1;

          if (!difference)
            {
              value_clear_c (date1);
              value_clear_c (date2);
              value_clear_c (date3);
              return 0;
            }
        }

      scattering = cloog_next_domain (scattering);
    }

  value_clear_c (date1);
  value_clear_c (date2);
  value_clear_c (date3);
  return 1;
}


/**
 * cloog_domain_lazy_disjoint function:
 * This function returns 1 if the domains given as input are disjoint, 0 if it
 * is unable to decide. This function finds the unknown with fixed values in
 * both domains (on a given constraint, their column entry is not zero and
 * only the constant coefficient can be different from zero) and verify that
 * their values are the same. If not, the domains are obviously disjoint and
 * it returns 1, if there is not such case it returns 0.  This is a very fast
 * way to verify this property. It has been shown (with the CLooG benchmarks)
 * that operations on disjoint domains are 36% of all the polyhedral
 * computations. For 94% of the actually identical domains, this
 * function answer that they are disjoint and allow to give immediately the
 * trivial solution instead of calling the heavy general functions of PolyLib.
 * - August 22th 2003: first version.
 * - June   21rd 2005: Adaptation for GMP (based on S. Verdoolaege's version of
 *                     CLooG 0.12.1).
 */
int
cloog_domain_lazy_disjoint (CloogDomain * d1, CloogDomain * d2)
{
  int i1, j1, i2, j2, scat_dim;
  Value scat_val;
  Polyhedron *p1, *p2;

  p1 = cloog_domain_polyhedron (d1);
  p2 = cloog_domain_polyhedron (d2);

  if (cloog_polyhedron_next (p1) || cloog_polyhedron_next (p2))
    return 0;

  value_init_c (scat_val);

  for (i1 = 0; i1 < cloog_polyhedron_nbc (p1); i1++)
    {
      if (value_notzero_p (p1->Constraint[i1][0]))
        continue;

      scat_dim = 1;
      while (value_zero_p (p1->Constraint[i1][scat_dim]) &&
             (scat_dim < cloog_polyhedron_dim (p1)))
        scat_dim++;

      if (value_notone_p (p1->Constraint[i1][scat_dim]))
        continue;
      else
        {
          for (j1 = scat_dim + 1; j1 <= cloog_polyhedron_dim (p1); j1++)
            if (value_notzero_p (p1->Constraint[i1][j1]))
              break;

          if (j1 != cloog_polyhedron_dim (p1) + 1)
            continue;

          value_assign (scat_val,
                        p1->Constraint[i1][cloog_polyhedron_dim (p1) + 1]);

          for (i2 = 0; i2 < cloog_polyhedron_nbc (p2); i2++)
            {
              for (j2 = 0; j2 < scat_dim; j2++)
                if (value_notzero_p (p2->Constraint[i2][j2]))
                  break;

              if ((j2 != scat_dim)
                  ||
                  value_notone_p (p2->Constraint[i2][scat_dim]))
                continue;

              for (j2 = scat_dim + 1; j2 < cloog_polyhedron_dim (p2); j2++)
                if (value_notzero_p (p2->Constraint[i2][j2]))
                  break;

              if (j2 != cloog_polyhedron_dim (p2))
                continue;

              if (value_ne
                  (p2->Constraint[i2][cloog_polyhedron_dim (p2) + 1], scat_val))
                {
                  value_clear_c (scat_val);
                  return 1;
                }
            }
        }
    }

  value_clear_c (scat_val);
  return 0;
}


/**
 * cloog_domain_list_lazy_same function:
 * This function returns 1 if two domains in the list are the same, 0 if it
 * is unable to decide.
 * - February 9th 2004: first version.
 */
int
cloog_domain_list_lazy_same (CloogDomainList * list)
{                               /*int i=1, j=1 ; */
  CloogDomainList *current, *next;

  current = list;
  while (current != NULL)
    {
      next = cloog_next_domain (current);
      /*j=i+1; */
      while (next != NULL)
        {
          if (cloog_domain_lazy_equal (cloog_domain (current),
                                       cloog_domain (next)))
            {                   /*printf("Same domains: %d and %d\n",i,j) ; */
              return 1;
            }
          /*j++ ; */
          next = cloog_next_domain (next);
        }
      /*i++ ; */
      current = cloog_next_domain (current);
    }

  return 0;
}

/**
 * cloog_domain_cut_first function:
 * this function returns a CloogDomain structure with everything except the
 * first part of the polyhedra union of the input domain as domain. After a call
 * to this function, there remains in the CloogDomain structure provided as
 * input only the first part of the original polyhedra union.
 * - April 20th 2005: first version, extracted from different part of loop.c.
 */
CloogDomain *
cloog_domain_cut_first (CloogDomain * domain)
{
  CloogDomain *rest;

  if ((domain != NULL) && (cloog_domain_polyhedron (domain) != NULL))
    {
      rest = cloog_domain_alloc (cloog_domain_polyhedron_next (domain));
      cloog_domain_polyhedron_set_next (domain, NULL);
    }
  else
    rest = NULL;

  return rest;
}


/**
 * cloog_domain_lazy_isscalar function:
 * this function returns 1 if the dimension 'dimension' in the domain 'domain'
 * is scalar, this means that the only constraint on this dimension must have
 * the shape "x.dimension + scalar = 0" with x an integral variable. This
 * function is lazy since we only accept x=1 (further calculations are easier
 * in this way).
 * - June 14th 2005: first version.
 * - June 21rd 2005: Adaptation for GMP.
 */
int
cloog_domain_lazy_isscalar (CloogDomain * domain, int dimension)
{
  int i, j;
  Polyhedron *polyhedron;

  polyhedron = cloog_domain_polyhedron (domain);
  /* For each constraint... */
  for (i = 0; i < cloog_polyhedron_nbc (polyhedron); i++)
    {                           /* ...if it is concerned by the potentially scalar dimension... */
      if (value_notzero_p
          (polyhedron->Constraint[i][dimension + 1]))
        {                       /* ...check that the constraint has the shape "dimension + scalar = 0". */
          for (j = 0; j <= dimension; j++)
            if (value_notzero_p (polyhedron->Constraint[i][j]))
              return 0;

          if (value_notone_p
              (polyhedron->Constraint[i][dimension + 1]))
            return 0;

          for (j = dimension + 2; j < (cloog_polyhedron_dim (polyhedron) + 1);
               j++)
            if (value_notzero_p (polyhedron->Constraint[i][j]))
              return 0;
        }
    }

  return 1;
}


/**
 * cloog_domain_scalar function:
 * when we call this function, we know that "dimension" is a scalar dimension,
 * this function finds the scalar value in "domain" and returns it in "value".
 * - June 30th 2005: first version.
 */
void
cloog_domain_scalar (CloogDomain * domain, int dimension, Value * value)
{
  int i;
  Polyhedron *polyhedron;

  polyhedron = cloog_domain_polyhedron (domain);
  /* For each constraint... */
  for (i = 0; i < cloog_polyhedron_nbc (polyhedron); i++)
    {                           /* ...if it is the equality defining the scalar dimension... */
      if (value_notzero_p
          (polyhedron->Constraint[i][dimension + 1])
          && value_zero_p (polyhedron->Constraint[i][0]))
        {                       /* ...Then send the scalar value. */
          value_assign (*value, polyhedron->Constraint[i][cloog_polyhedron_dim (polyhedron) + 1]);
          value_oppose (*value, *value);
          return;
        }
    }

  /* We should have found a scalar value: if not, there is an error. */
  fprintf (stderr, "[CLooG]ERROR: dimension %d is not scalar as expected.\n",
           dimension);
  exit (0);
}


/**
 * cloog_domain_erase_dimension function:
 * this function returns a CloogDomain structure builds from 'domain' where
 * we removed the dimension 'dimension' and every constraint considering this
 * dimension. This is not a projection ! Every data concerning the
 * considered dimension is simply erased.
 * - June 14th 2005: first version.
 * - June 21rd 2005: Adaptation for GMP.
 */
CloogDomain *
cloog_domain_erase_dimension (CloogDomain * domain, int dimension)
{
  int i, j, mi, nb_dim;
  CloogMatrix *matrix;
  CloogDomain *erased;
  Polyhedron *polyhedron;

  polyhedron = cloog_domain_polyhedron (domain);
  nb_dim = cloog_domain_dim (domain);

  /* The matrix is one column less and at least one constraint less. */
  matrix =
    cloog_matrix_alloc (cloog_polyhedron_nbc (polyhedron) - 1, nb_dim + 1);

  /* mi is the constraint counter for the matrix. */
  mi = 0;
  for (i = 0; i < cloog_polyhedron_nbc (polyhedron); i++)
    if (value_zero_p (polyhedron->Constraint[i][dimension + 1]))
      {
        for (j = 0; j <= dimension; j++)
          value_assign (matrix->p[mi][j],
                        polyhedron->Constraint[i][j]);

        for (j = dimension + 2; j < nb_dim + 2; j++)
          value_assign (matrix->p[mi][j - 1],
                        polyhedron->Constraint[i][j]);

        mi++;
      }

  erased = cloog_domain_matrix2domain (matrix);
  cloog_matrix_free (matrix);

  return erased;
}

/* Number of polyhedra inside the union of disjoint polyhedra.  */

unsigned
cloog_domain_nb_polyhedra (CloogDomain * domain)
{
  unsigned j = 0;
  Polyhedron *polyhedron = cloog_domain_polyhedron (domain);

  while (polyhedron != NULL)
    {
      j++;
      polyhedron = polyhedron->next;
    }
  return j;
}


void
cloog_domain_print_polyhedra (FILE * foo, CloogDomain * domain)
{
  Polyhedron *polyhedron = cloog_domain_polyhedron (domain);

  while (polyhedron != NULL)
    {
      CloogMatrix *matrix;
      matrix = Polyhedron2Constraints (polyhedron);
      cloog_matrix_print (foo, matrix);
      cloog_matrix_free (matrix);
      polyhedron = polyhedron->next;
    }
}