/*

 * Copyright 2010-2011 INRIA Saclay

 * Copyright 2014      Ecole Normale Superieure

 *

 * Use of this software is governed by the MIT license

 *

 * Written by Sven Verdoolaege, INRIA Saclay - Ile-de-France,

 * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,

 * 91893 Orsay, France 

 * and Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France

 */

#include <isl_map_private.h>

#include <isl_aff_private.h>

#include <isl_morph.h>

#include <isl_seq.h>

#include <isl_mat_private.h>

#include <isl_space_private.h>

#include <isl_equalities.h>

#include <isl_id_private.h>

isl_ctx *isl_morph_get_ctx(__isl_keep isl_morph *morph)

{

  if (!morph)

    return NULL;

  return isl_basic_set_get_ctx(morph->dom);

}

__isl_give isl_morph *isl_morph_alloc(

  __isl_take isl_basic_set *dom, __isl_take isl_basic_set *ran,

  __isl_take isl_mat *map, __isl_take isl_mat *inv)

{

  isl_morph *morph;

  if (!dom || !ran || !map || !inv)

    goto error;

  morph = isl_alloc_type(dom->ctx, struct isl_morph);

  if (!morph)

    goto error;

  morph->ref = 1;

  morph->dom = dom;

  morph->ran = ran;

  morph->map = map;

  morph->inv = inv;

  return morph;

error:

  isl_basic_set_free(dom);

  isl_basic_set_free(ran);

  isl_mat_free(map);

  isl_mat_free(inv);

  return NULL;

}

__isl_give isl_morph *isl_morph_copy(__isl_keep isl_morph *morph)

{

  if (!morph)

    return NULL;

  morph->ref++;

  return morph;

}

__isl_give isl_morph *isl_morph_dup(__isl_keep isl_morph *morph)

{

  if (!morph)

    return NULL;

  return isl_morph_alloc(isl_basic_set_copy(morph->dom),

    isl_basic_set_copy(morph->ran),

    isl_mat_copy(morph->map), isl_mat_copy(morph->inv));

}

__isl_give isl_morph *isl_morph_cow(__isl_take isl_morph *morph)

{

  if (!morph)

    return NULL;

  if (morph->ref == 1)

    return morph;

  morph->ref--;

  return isl_morph_dup(morph);

}

__isl_null isl_morph *isl_morph_free(__isl_take isl_morph *morph)

{

  if (!morph)

    return NULL;

  if (--morph->ref > 0)

    return NULL;

  isl_basic_set_free(morph->dom);

  isl_basic_set_free(morph->ran);

  isl_mat_free(morph->map);

  isl_mat_free(morph->inv);

  free(morph);

  return NULL;

}

/* Is "morph" an identity on the parameters?

 */

static int identity_on_parameters(__isl_keep isl_morph *morph)

{

  int is_identity;

  unsigned nparam;

  isl_mat *sub;

  nparam = isl_morph_dom_dim(morph, isl_dim_param);

  if (nparam != isl_morph_ran_dim(morph, isl_dim_param))

    return 0;

  if (nparam == 0)

    return 1;

  sub = isl_mat_sub_alloc(morph->map, 0, 1 + nparam, 0, 1 + nparam);

  is_identity = isl_mat_is_scaled_identity(sub);

  isl_mat_free(sub);

  return is_identity;

}

/* Return an affine expression of the variables of the range of "morph"

 * in terms of the parameters and the variables of the domain on "morph".

 *

 * In order for the space manipulations to make sense, we require

 * that the parameters are not modified by "morph".

 */

__isl_give isl_multi_aff *isl_morph_get_var_multi_aff(

  __isl_keep isl_morph *morph)

{

  isl_space *dom, *ran, *space;

  isl_local_space *ls;

  isl_multi_aff *ma;

  unsigned nparam, nvar;

  int i;

  int is_identity;

  if (!morph)

    return NULL;

  is_identity = identity_on_parameters(morph);

  if (is_identity < 0)

    return NULL;

  if (!is_identity)

    
isl_die0
(isl_morph_get_ctx(morph), isl_error_invalid,

      "cannot handle parameter compression", return NULL);

  dom = isl_morph_get_dom_space(morph);

  ls = isl_local_space_from_space(isl_space_copy(dom));

  ran = isl_morph_get_ran_space(morph);

  space = isl_space_map_from_domain_and_range(dom, ran);

  ma = isl_multi_aff_zero(space);

  nparam = isl_multi_aff_dim(ma, isl_dim_param);

  nvar = isl_multi_aff_dim(ma, isl_dim_out);

  for (i = 0; i < nvar; 
++i24
) {

    isl_val *val;

    isl_vec *v;

    isl_aff *aff;

    v = isl_mat_get_row(morph->map, 1 + nparam + i);

    v = isl_vec_insert_els(v, 0, 1);

    val = isl_mat_get_element_val(morph->map, 0, 0);

    v = isl_vec_set_element_val(v, 0, val);

    aff = isl_aff_alloc_vec(isl_local_space_copy(ls), v);

    ma = isl_multi_aff_set_aff(ma, i, aff);

  }

  isl_local_space_free(ls);

  return ma;

}

/* Return the domain space of "morph".

 */

__isl_give isl_space *isl_morph_get_dom_space(__isl_keep isl_morph *morph)

{

  if (!morph)

    return NULL;

  return isl_basic_set_get_space(morph->dom);

}

__isl_give isl_space *isl_morph_get_ran_space(__isl_keep isl_morph *morph)

{

  if (!morph)

    return NULL;

  return isl_space_copy(morph->ran->dim);

}

unsigned isl_morph_dom_dim(__isl_keep isl_morph *morph, enum isl_dim_type type)

{

  if (!morph)

    return 0;

  return isl_basic_set_dim(morph->dom, type);

}

unsigned isl_morph_ran_dim(__isl_keep isl_morph *morph, enum isl_dim_type type)

{

  if (!morph)

    return 0;

  return isl_basic_set_dim(morph->ran, type);

}

__isl_give isl_morph *isl_morph_remove_dom_dims(__isl_take isl_morph *morph,

  enum isl_dim_type type, unsigned first, unsigned n)

{

  unsigned dom_offset;

  if (n == 0)

    return morph;

  morph = isl_morph_cow(morph);

  if (!morph)

    return NULL;

  dom_offset = 1 + isl_space_offset(morph->dom->dim, type);

  morph->dom = isl_basic_set_remove_dims(morph->dom, type, first, n);

  morph->map = isl_mat_drop_cols(morph->map, dom_offset + first, n);

  morph->inv = isl_mat_drop_rows(morph->inv, dom_offset + first, n);

  if (morph->dom && morph->ran && morph->map && morph->inv)

    return morph;

  isl_morph_free(morph);

  return NULL;

}

__isl_give isl_morph *isl_morph_remove_ran_dims(__isl_take isl_morph *morph,

  enum isl_dim_type type, unsigned first, unsigned n)

{

  unsigned ran_offset;

  if (n == 0)

    return morph;

  morph = isl_morph_cow(morph);

  if (!morph)

    return NULL;

  ran_offset = 1 + isl_space_offset(morph->ran->dim, type);

  morph->ran = isl_basic_set_remove_dims(morph->ran, type, first, n);

  morph->map = isl_mat_drop_rows(morph->map, ran_offset + first, n);

  morph->inv = isl_mat_drop_cols(morph->inv, ran_offset + first, n);

  if (morph->dom && morph->ran && morph->map && morph->inv)

    return morph;

  isl_morph_free(morph);

  return NULL;

}

/* Project domain of morph onto its parameter domain.

 */

__isl_give isl_morph *isl_morph_dom_params(__isl_take isl_morph *morph)

{

  unsigned n;

  morph = isl_morph_cow(morph);

  if (!morph)

    return NULL;

  n = isl_basic_set_dim(morph->dom, isl_dim_set);

  morph = isl_morph_remove_dom_dims(morph, isl_dim_set, 0, n);

  if (!morph)

    return NULL;

  morph->dom = isl_basic_set_params(morph->dom);

  if (morph->dom)

    return morph;

  isl_morph_free(morph);

  return NULL;

}

/* Project range of morph onto its parameter domain.

 */

__isl_give isl_morph *isl_morph_ran_params(__isl_take isl_morph *morph)

{

  unsigned n;

  morph = isl_morph_cow(morph);

  if (!morph)

    return NULL;

  n = isl_basic_set_dim(morph->ran, isl_dim_set);

  morph = isl_morph_remove_ran_dims(morph, isl_dim_set, 0, n);

  if (!morph)

    return NULL;

  morph->ran = isl_basic_set_params(morph->ran);

  if (morph->ran)

    return morph;

  isl_morph_free(morph);

  return NULL;

}

void isl_morph_print_internal(__isl_take isl_morph *morph, FILE *out)

{

  if (!morph)

    return;

  isl_basic_set_dump(morph->dom);

  isl_basic_set_dump(morph->ran);

  isl_mat_print_internal(morph->map, out, 4);

  isl_mat_print_internal(morph->inv, out, 4);

}

void isl_morph_dump(__isl_take isl_morph *morph)

{

  isl_morph_print_internal(morph, stderr);

}

__isl_give isl_morph *isl_morph_identity(__isl_keep isl_basic_set *bset)

{

  isl_mat *id;

  isl_basic_set *universe;

  unsigned total;

  if (!bset)

    return NULL;

  total = isl_basic_set_total_dim(bset);

  id = isl_mat_identity(bset->ctx, 1 + total);

  universe = isl_basic_set_universe(isl_space_copy(bset->dim));

  return isl_morph_alloc(universe, isl_basic_set_copy(universe),

    id, isl_mat_copy(id));

}

/* Create a(n identity) morphism between empty sets of the same dimension

 * a "bset".

 */

__isl_give isl_morph *isl_morph_empty(__isl_keep isl_basic_set *bset)

{

  isl_mat *id;

  isl_basic_set *empty;

  unsigned total;

  if (!bset)

    return NULL;

  total = isl_basic_set_total_dim(bset);

  id = isl_mat_identity(bset->ctx, 1 + total);

  empty = isl_basic_set_empty(isl_space_copy(bset->dim));

  return isl_morph_alloc(empty, isl_basic_set_copy(empty),

    id, isl_mat_copy(id));

}

/* Construct a basic set described by the "n" equalities of "bset" starting

 * at "first".

 */

static __isl_give isl_basic_set *copy_equalities(__isl_keep isl_basic_set *bset,

  unsigned first, unsigned n)

{

  int i, k;

  isl_basic_set *eq;

  unsigned total;

  isl_assert(bset->ctx, bset->n_div == 0, return NULL);

  total = isl_basic_set_total_dim(bset);

  eq = isl_basic_set_alloc_space(isl_space_copy(bset->dim), 0, n, 0);

  if (!eq)

    return NULL;

  
for (i = 0; 11
i < n; 
++i13
) {

    k = isl_basic_set_alloc_equality(eq);

    if (k < 0)

      goto error;

    isl_seq_cpy(eq->eq[k], bset->eq[first + i], 1 + total);

  }

  return eq;

error:

  isl_basic_set_free(eq);

  return NULL;

}

/* Given a basic set, exploit the equalities in the basic set to construct

 * a morphism that maps the basic set to a lower-dimensional space

 * with identifier "id".

 * Specifically, the morphism reduces the number of dimensions of type "type".

 *

 * We first select the equalities of interest, that is those that involve

 * variables of type "type" and no later variables.

 * Denote those equalities as

 *

 *    -C(p) + M x = 0

 *

 * where C(p) depends on the parameters if type == isl_dim_set and

 * is a constant if type == isl_dim_param.

 *

 * Use isl_mat_final_variable_compression to construct a compression

 *

 *  x = T x'

 *

 *  x' = Q x

 *

 * If T is a zero-column matrix, then the set of equality constraints

 * do not admit a solution.  In this case, an empty morphism is returned.

 *

 * Both matrices are extended to map the full original space to the full

 * compressed space.

 */

__isl_give isl_morph *isl_basic_set_variable_compression_with_id(

  __isl_keep isl_basic_set *bset, enum isl_dim_type type,

  __isl_keep isl_id *id)

{

  unsigned otype;

  unsigned ntype;

  unsigned orest;

  unsigned nrest;

  int f_eq, n_eq;

  isl_space *space;

  isl_mat *E, *Q, *C;

  isl_basic_set *dom, *ran;

  if (!bset)

    return NULL;

  if (isl_basic_set_plain_is_empty(bset))

    return isl_morph_empty(bset);

  isl_assert(bset->ctx, bset->n_div == 0, return NULL);

  otype = 1 + isl_space_offset(bset->dim, type);

  ntype = isl_basic_set_dim(bset, type);

  orest = otype + ntype;

  nrest = isl_basic_set_total_dim(bset) - (orest - 1);

  for (f_eq = 0; f_eq < bset->n_eq; 
++f_eq5
)

    if (isl_seq_first_non_zero(bset->eq[f_eq] + orest, nrest) == -1)

      break;

  for (n_eq = 0; f_eq + n_eq < bset->n_eq; 
++n_eq13
)

    if (isl_seq_first_non_zero(bset->eq[f_eq + n_eq] + otype, ntype) == -1)

      break;

  if (n_eq == 0)

    return isl_morph_identity(bset);

  E = isl_mat_sub_alloc6(bset->ctx, bset->eq, f_eq, n_eq, 0, orest);

  C = isl_mat_final_variable_compression(E, otype - 1, &Q);

  if (!Q)

    C = isl_mat_free(C);

  if (C && C->n_col == 0) {

    isl_mat_free(C);

    isl_mat_free(Q);

    return isl_morph_empty(bset);

  }

  Q = isl_mat_diagonal(Q, isl_mat_identity(bset->ctx, nrest));

  C = isl_mat_diagonal(C, isl_mat_identity(bset->ctx, nrest));

  space = isl_space_copy(bset->dim);

  space = isl_space_drop_dims(space, type, 0, ntype);

  space = isl_space_add_dims(space, type, ntype - n_eq);

  space = isl_space_set_tuple_id(space, isl_dim_set, isl_id_copy(id));

  ran = isl_basic_set_universe(space);

  dom = copy_equalities(bset, f_eq, n_eq);

  return isl_morph_alloc(dom, ran, Q, C);

}

/* Given a basic set, exploit the equalities in the basic set to construct

 * a morphism that maps the basic set to a lower-dimensional space.

 * Specifically, the morphism reduces the number of dimensions of type "type".

 */

__isl_give isl_morph *isl_basic_set_variable_compression(

  __isl_keep isl_basic_set *bset, enum isl_dim_type type)

{

  return isl_basic_set_variable_compression_with_id(bset, type,

              &isl_id_none);

}

/* Construct a parameter compression for "bset".

 * We basically just call isl_mat_parameter_compression with the right input

 * and then extend the resulting matrix to include the variables.

 *

 * The implementation assumes that "bset" does not have any equalities

 * that only involve the parameters and that isl_basic_set_gauss has

 * been applied to "bset".

 *

 * Let the equalities be given as

 *

 *  B(p) + A x = 0.

 *

 * We use isl_mat_parameter_compression_ext to compute the compression

 *

 *  p = T p'.

 */

__isl_give isl_morph *isl_basic_set_parameter_compression(

  __isl_keep isl_basic_set *bset)

{

  unsigned nparam;

  unsigned nvar;

  unsigned n_div;

  int n_eq;

  isl_mat *H, *B;

  isl_mat *map, *inv;

  isl_basic_set *dom, *ran;

  if (!bset)

    return NULL;

  if (isl_basic_set_plain_is_empty(bset))

    return isl_morph_empty(bset);

  if (bset->n_eq == 0)

    return isl_morph_identity(bset);

  n_eq = bset->n_eq;

  nparam = isl_basic_set_dim(bset, isl_dim_param);

  nvar = isl_basic_set_dim(bset, isl_dim_set);

  n_div = isl_basic_set_dim(bset, isl_dim_div);

  if (isl_seq_first_non_zero(bset->eq[bset->n_eq - 1] + 1 + nparam,

            nvar + n_div) == -1)

    
isl_die0
(isl_basic_set_get_ctx(bset), isl_error_invalid,

      "input not allowed to have parameter equalities",

      return NULL);

  if (n_eq > nvar + n_div)

    
isl_die0
(isl_basic_set_get_ctx(bset), isl_error_invalid,

      "input not gaussed", return NULL);

  B = isl_mat_sub_alloc6(bset->ctx, bset->eq, 0, n_eq, 0, 1 + nparam);

  H = isl_mat_sub_alloc6(bset->ctx, bset->eq,

        0, n_eq, 1 + nparam, nvar + n_div);

  inv = isl_mat_parameter_compression_ext(B, H);

  inv = isl_mat_diagonal(inv, isl_mat_identity(bset->ctx, nvar));

  map = isl_mat_right_inverse(isl_mat_copy(inv));

  dom = isl_basic_set_universe(isl_space_copy(bset->dim));

  ran = isl_basic_set_universe(isl_space_copy(bset->dim));

  return isl_morph_alloc(dom, ran, map, inv);

}

/* Add stride constraints to "bset" based on the inverse mapping

 * that was plugged in.  In particular, if morph maps x' to x,

 * the constraints of the original input

 *

 *  A x' + b >= 0

 *

 * have been rewritten to

 *

 *  A inv x + b >= 0

 *

 * However, this substitution may loose information on the integrality of x',

 * so we need to impose that

 *

 *  inv x

 *

 * is integral.  If inv = B/d, this means that we need to impose that

 *

 *  B x = 0   mod d

 *

 * or

 *

 *  exists alpha in Z^m: B x = d alpha

 *

 * This function is similar to add_strides in isl_affine_hull.c

 */

static __isl_give isl_basic_set *add_strides(__isl_take isl_basic_set *bset,

  __isl_keep isl_morph *morph)

{

  int i, div, k;

  isl_int gcd;

  if (isl_int_is_one(morph->inv->row[0][0]))

    
return bset94.0k
;

  isl_int_init(gcd);

  for (i = 0; 1 + i < morph->inv->n_row; 
++i4
) {

    isl_seq_gcd(morph->inv->row[1 + i], morph->inv->n_col, &gcd);

    if (isl_int_is_divisible_by(gcd, morph->inv->row[0][0]))

      
continue2
;

    div = isl_basic_set_alloc_div(bset);

    if (div < 0)

      goto error;

    isl_int_set_si(bset->div[div][0], 0);

    k = isl_basic_set_alloc_equality(bset);

    if (k < 0)

      goto error;

    isl_seq_cpy(bset->eq[k], morph->inv->row[1 + i],

          morph->inv->n_col);

    isl_seq_clr(bset->eq[k] + morph->inv->n_col, bset->n_div);

    isl_int_set(bset->eq[k][morph->inv->n_col + div],

          morph->inv->row[0][0]);

  }

  isl_int_clear(gcd);

  return bset;

error:

  isl_int_clear(gcd);

  isl_basic_set_free(bset);

  return NULL;

}

/* Apply the morphism to the basic set.

 * We basically just compute the preimage of "bset" under the inverse mapping

 * in morph, add in stride constraints and intersect with the range

 * of the morphism.

 */

__isl_give isl_basic_set *isl_morph_basic_set(__isl_take isl_morph *morph,

  __isl_take isl_basic_set *bset)

{

  isl_basic_set *res = NULL;

  isl_mat *mat = NULL;

  int i, k;

  int max_stride;

  if (!morph || !bset)

    goto error;

  isl_assert(bset->ctx, isl_space_is_equal(bset->dim, morph->dom->dim),

        goto error);

  max_stride = morph->inv->n_row - 1;

  if (isl_int_is_one(morph->inv->row[0][0]))

    
max_stride = 094.0k
;

  res = isl_basic_set_alloc_space(isl_space_copy(morph->ran->dim),

    bset->n_div + max_stride, bset->n_eq + max_stride, bset->n_ineq);

  for (i = 0; i < bset->n_div; 
++i0
)

    if (isl_basic_set_alloc_div(res) < 0)

      goto error;

  mat = isl_mat_sub_alloc6(bset->ctx, bset->eq, 0, bset->n_eq,

          0, morph->inv->n_row);

  mat = isl_mat_product(mat, isl_mat_copy(morph->inv));

  if (!mat)

    goto error;

  
for (i = 0; 94.0k
i < bset->n_eq; 
++i22
) {

    k = isl_basic_set_alloc_equality(res);

    if (k < 0)

      goto error;

    isl_seq_cpy(res->eq[k], mat->row[i], mat->n_col);

    isl_seq_scale(res->eq[k] + mat->n_col, bset->eq[i] + mat->n_col,

        morph->inv->row[0][0], bset->n_div);

  }

  isl_mat_free(mat);

  mat = isl_mat_sub_alloc6(bset->ctx, bset->ineq, 0, bset->n_ineq,

          0, morph->inv->n_row);

  mat = isl_mat_product(mat, isl_mat_copy(morph->inv));

  if (!mat)

    goto error;

  
for (i = 0; 94.0k
i < bset->n_ineq; 
++i912k
) {

    k = isl_basic_set_alloc_inequality(res);

    if (k < 0)

      goto error;

    isl_seq_cpy(res->ineq[k], mat->row[i], mat->n_col);

    isl_seq_scale(res->ineq[k] + mat->n_col,

        bset->ineq[i] + mat->n_col,

        morph->inv->row[0][0], bset->n_div);

  }

  isl_mat_free(mat);

  mat = isl_mat_sub_alloc6(bset->ctx, bset->div, 0, bset->n_div,

          1, morph->inv->n_row);

  mat = isl_mat_product(mat, isl_mat_copy(morph->inv));

  if (!mat)

    goto error;

  for (i = 0; i < bset->n_div; 
++i0
) {

    isl_int_mul(res->div[i][0],

        morph->inv->row[0][0], bset->div[i][0]);

    isl_seq_cpy(res->div[i] + 1, mat->row[i], mat->n_col);

    isl_seq_scale(res->div[i] + 1 + mat->n_col,

        bset->div[i] + 1 + mat->n_col,

        morph->inv->row[0][0], bset->n_div);

  }

  isl_mat_free(mat);

  res = add_strides(res, morph);

  if (isl_basic_set_is_rational(bset))

    res = isl_basic_set_set_rational(res);

  res = isl_basic_set_simplify(res);

  res = isl_basic_set_finalize(res);

  res = isl_basic_set_intersect(res, isl_basic_set_copy(morph->ran));

  isl_morph_free(morph);

  isl_basic_set_free(bset);

  return res;

error:

  isl_mat_free(mat);

  isl_morph_free(morph);

  isl_basic_set_free(bset);

  isl_basic_set_free(res);

  return NULL;

}

/* Apply the morphism to the set.

 */

__isl_give isl_set *isl_morph_set(__isl_take isl_morph *morph,

  __isl_take isl_set *set)

{

  int i;

  if (!morph || !set)

    goto error;

  isl_assert(set->ctx, isl_space_is_equal(set->dim, morph->dom->dim), goto error);

  set = isl_set_cow(set);

  if (!set)

    goto error;

  isl_space_free(set->dim);

  set->dim = isl_space_copy(morph->ran->dim);

  if (!set->dim)

    goto error;

  
for (i = 0; 1
i < set->n; 
++i1
) {

    set->p[i] = isl_morph_basic_set(isl_morph_copy(morph), set->p[i]);

    if (!set->p[i])

      goto error;

  }

  isl_morph_free(morph);

  ISL_F_CLR(set, ISL_SET_NORMALIZED);

  return set;

error:

  isl_set_free(set);

  isl_morph_free(morph);

  return NULL;

}

/* Construct a morphism that first does morph2 and then morph1.

 */

__isl_give isl_morph *isl_morph_compose(__isl_take isl_morph *morph1,

  __isl_take isl_morph *morph2)

{

  isl_mat *map, *inv;

  isl_basic_set *dom, *ran;

  if (!morph1 || !morph2)

    goto error;

  map = isl_mat_product(isl_mat_copy(morph1->map), isl_mat_copy(morph2->map));

  inv = isl_mat_product(isl_mat_copy(morph2->inv), isl_mat_copy(morph1->inv));

  dom = isl_morph_basic_set(isl_morph_inverse(isl_morph_copy(morph2)),

          isl_basic_set_copy(morph1->dom));

  dom = isl_basic_set_intersect(dom, isl_basic_set_copy(morph2->dom));

  ran = isl_morph_basic_set(isl_morph_copy(morph1),

          isl_basic_set_copy(morph2->ran));

  ran = isl_basic_set_intersect(ran, isl_basic_set_copy(morph1->ran));

  isl_morph_free(morph1);

  isl_morph_free(morph2);

  return isl_morph_alloc(dom, ran, map, inv);

error:

  isl_morph_free(morph1);

  isl_morph_free(morph2);

  return NULL;

}

__isl_give isl_morph *isl_morph_inverse(__isl_take isl_morph *morph)

{

  isl_basic_set *bset;

  isl_mat *mat;

  morph = isl_morph_cow(morph);

  if (!morph)

    return NULL;

  bset = morph->dom;

  morph->dom = morph->ran;

  morph->ran = bset;

  mat = morph->map;

  morph->map = morph->inv;

  morph->inv = mat;

  return morph;

}

/* We detect all the equalities first to avoid implicit equalities

 * being discovered during the computations.  In particular,

 * the compression on the variables could expose additional stride

 * constraints on the parameters.  This would result in existentially

 * quantified variables after applying the resulting morph, which

 * in turn could break invariants of the calling functions.

 */

__isl_give isl_morph *isl_basic_set_full_compression(

  __isl_keep isl_basic_set *bset)

{

  isl_morph *morph, *morph2;

  bset = isl_basic_set_copy(bset);

  bset = isl_basic_set_detect_equalities(bset);

  morph = isl_basic_set_variable_compression(bset, isl_dim_param);

  bset = isl_morph_basic_set(isl_morph_copy(morph), bset);

  morph2 = isl_basic_set_parameter_compression(bset);

  bset = isl_morph_basic_set(isl_morph_copy(morph2), bset);

  morph = isl_morph_compose(morph2, morph);

  morph2 = isl_basic_set_variable_compression(bset, isl_dim_set);

  isl_basic_set_free(bset);

  morph = isl_morph_compose(morph2, morph);

  return morph;

}

__isl_give isl_vec *isl_morph_vec(__isl_take isl_morph *morph,

  __isl_take isl_vec *vec)

{

  if (!morph)

    goto error;

  vec = isl_mat_vec_product(isl_mat_copy(morph->map), vec);

  isl_morph_free(morph);

  return vec;

error:

  isl_morph_free(morph);

  isl_vec_free(vec);

  return NULL;

}