/*

 * Copyright 2008-2009 Katholieke Universiteit Leuven

 *

 * Use of this software is governed by the MIT license

 *

 * Written by Sven Verdoolaege, K.U.Leuven, Departement

 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium

 */

#include <isl_ctx_private.h>

#include <isl_map_private.h>

#include <isl/ilp.h>

#include <isl/union_set.h>

#include "isl_sample.h"

#include <isl_seq.h>

#include "isl_equalities.h"

#include <isl_aff_private.h>

#include <isl_local_space_private.h>

#include <isl_mat_private.h>

#include <isl_val_private.h>

#include <isl_vec_private.h>

#include <isl_lp_private.h>

#include <isl_ilp_private.h>

/* Given a basic set "bset", construct a basic set U such that for

 * each element x in U, the whole unit box positioned at x is inside

 * the given basic set.

 * Note that U may not contain all points that satisfy this property.

 *

 * We simply add the sum of all negative coefficients to the constant

 * term.  This ensures that if x satisfies the resulting constraints,

 * then x plus any sum of unit vectors satisfies the original constraints.

 */

static __isl_give isl_basic_set *unit_box_base_points(

  __isl_take isl_basic_set *bset)

{

  int i, j, k;

  struct isl_basic_set *unit_box = NULL;

  unsigned total;

  if (!bset)

    goto error;

  if (bset->n_eq != 0) {

    isl_space *space = isl_basic_set_get_space(bset);

    isl_basic_set_free(bset);

    return isl_basic_set_empty(space);

  }

  total = isl_basic_set_total_dim(bset);

  unit_box = isl_basic_set_alloc_space(isl_basic_set_get_space(bset),

          0, 0, bset->n_ineq);

  for (i = 0; i < bset->n_ineq; 
++i763
) {

    k = isl_basic_set_alloc_inequality(unit_box);

    if (k < 0)

      goto error;

    isl_seq_cpy(unit_box->ineq[k], bset->ineq[i], 1 + total);

    for (j = 0; j < total; 
++j6.09k
) {

      if (isl_int_is_nonneg(unit_box->ineq[k][1 + j]))

        
continue5.62k
;

      isl_int_add(unit_box->ineq[k][0],

        unit_box->ineq[k][0], unit_box->ineq[k][1 + j]);

    }

  }

  isl_basic_set_free(bset);

  return unit_box;

error:

  isl_basic_set_free(bset);

  isl_basic_set_free(unit_box);

  return NULL;

}

/* Find an integer point in "bset", preferably one that is

 * close to minimizing "f".

 *

 * We first check if we can easily put unit boxes inside bset.

 * If so, we take the best base point of any of the unit boxes we can find

 * and round it up to the nearest integer.

 * If not, we simply pick any integer point in "bset".

 */

static __isl_give isl_vec *initial_solution(__isl_keep isl_basic_set *bset,

  isl_int *f)

{

  enum isl_lp_result res;

  struct isl_basic_set *unit_box;

  struct isl_vec *sol;

  unit_box = unit_box_base_points(isl_basic_set_copy(bset));

  res = isl_basic_set_solve_lp(unit_box, 0, f, bset->ctx->one,

          NULL, NULL, &sol);

  if (res == isl_lp_ok) {

    isl_basic_set_free(unit_box);

    return isl_vec_ceil(sol);

  }

  isl_basic_set_free(unit_box);

  return isl_basic_set_sample_vec(isl_basic_set_copy(bset));

}

/* Restrict "bset" to those points with values for f in the interval [l, u].

 */

static __isl_give isl_basic_set *add_bounds(__isl_take isl_basic_set *bset,

  isl_int *f, isl_int l, isl_int u)

{

  int k;

  unsigned total;

  total = isl_basic_set_total_dim(bset);

  bset = isl_basic_set_extend_constraints(bset, 0, 2);

  k = isl_basic_set_alloc_inequality(bset);

  if (k < 0)

    goto error;

  isl_seq_cpy(bset->ineq[k], f, 1 + total);

  isl_int_sub(bset->ineq[k][0], bset->ineq[k][0], l);

  k = isl_basic_set_alloc_inequality(bset);

  if (k < 0)

    goto error;

  isl_seq_neg(bset->ineq[k], f, 1 + total);

  isl_int_add(bset->ineq[k][0], bset->ineq[k][0], u);

  return bset;

error:

  isl_basic_set_free(bset);

  return NULL;

}

/* Find an integer point in "bset" that minimizes f (in any) such that

 * the value of f lies inside the interval [l, u].

 * Return this integer point if it can be found.

 * Otherwise, return sol.

 *

 * We perform a number of steps until l > u.

 * In each step, we look for an integer point with value in either

 * the whole interval [l, u] or half of the interval [l, l+floor(u-l-1/2)].

 * The choice depends on whether we have found an integer point in the

 * previous step.  If so, we look for the next point in half of the remaining

 * interval.

 * If we find a point, the current solution is updated and u is set

 * to its value minus 1.

 * If no point can be found, we update l to the upper bound of the interval

 * we checked (u or l+floor(u-l-1/2)) plus 1.

 */

static __isl_give isl_vec *solve_ilp_search(__isl_keep isl_basic_set *bset,

  isl_int *f, isl_int *opt, __isl_take isl_vec *sol, isl_int l, isl_int u)

{

  isl_int tmp;

  int divide = 1;

  isl_int_init(tmp);

  while (isl_int_le(l, u)) {

    struct isl_basic_set *slice;

    struct isl_vec *sample;

    if (!divide)

      
isl_int_set7
(tmp, u);

    else {

      isl_int_sub(tmp, u, l);

      isl_int_fdiv_q_ui(tmp, tmp, 2);

      isl_int_add(tmp, tmp, l);

    }

    slice = add_bounds(isl_basic_set_copy(bset), f, l, tmp);

    sample = isl_basic_set_sample_vec(slice);

    if (!sample) {

      isl_vec_free(sol);

      sol = NULL;

      break;

    }

    if (sample->size > 0) {

      isl_vec_free(sol);

      sol = sample;

      isl_seq_inner_product(f, sol->el, sol->size, opt);

      isl_int_sub_ui(u, *opt, 1);

      divide = 1;

    } else {

      isl_vec_free(sample);

      if (!divide)

        break;

      isl_int_add_ui(l, tmp, 1);

      divide = 0;

    }

  }

  isl_int_clear(tmp);

  return sol;

}

/* Find an integer point in "bset" that minimizes f (if any).

 * If sol_p is not NULL then the integer point is returned in *sol_p.

 * The optimal value of f is returned in *opt.

 *

 * The algorithm maintains a currently best solution and an interval [l, u]

 * of values of f for which integer solutions could potentially still be found.

 * The initial value of the best solution so far is any solution.

 * The initial value of l is minimal value of f over the rationals

 * (rounded up to the nearest integer).

 * The initial value of u is the value of f at the initial solution minus 1.

 *

 * We then call solve_ilp_search to perform a binary search on the interval.

 */

static enum isl_lp_result solve_ilp(__isl_keep isl_basic_set *bset,

  isl_int *f, isl_int *opt, __isl_give isl_vec **sol_p)

{

  enum isl_lp_result res;

  isl_int l, u;

  struct isl_vec *sol;

  res = isl_basic_set_solve_lp(bset, 0, f, bset->ctx->one,

          opt, NULL, &sol);

  if (res == isl_lp_ok && 
isl_int_is_one3.37k
(sol->el[0])) {

    if (sol_p)

      *sol_p = sol;

    else

      isl_vec_free(sol);

    return isl_lp_ok;

  }

  isl_vec_free(sol);

  if (res == isl_lp_error || res == isl_lp_empty)

    return res;

  sol = initial_solution(bset, f);

  if (!sol)

    return isl_lp_error;

  if (sol->size == 0) {

    isl_vec_free(sol);

    return isl_lp_empty;

  }

  if (res == isl_lp_unbounded) {

    isl_vec_free(sol);

    return isl_lp_unbounded;

  }

  isl_int_init(l);

  isl_int_init(u);

  isl_int_set(l, *opt);

  isl_seq_inner_product(f, sol->el, sol->size, opt);

  isl_int_sub_ui(u, *opt, 1);

  sol = solve_ilp_search(bset, f, opt, sol, l, u);

  if (!sol)

    res = isl_lp_error;

  isl_int_clear(l);

  isl_int_clear(u);

  if (sol_p)

    *sol_p = sol;

  else

    isl_vec_free(sol);

  return res;

}

static enum isl_lp_result solve_ilp_with_eq(__isl_keep isl_basic_set *bset,

  int max, isl_int *f, isl_int *opt, __isl_give isl_vec **sol_p)

{

  unsigned dim;

  enum isl_lp_result res;

  struct isl_mat *T = NULL;

  struct isl_vec *v;

  bset = isl_basic_set_copy(bset);

  dim = isl_basic_set_total_dim(bset);

  v = isl_vec_alloc(bset->ctx, 1 + dim);

  if (!v)

    goto error;

  isl_seq_cpy(v->el, f, 1 + dim);

  bset = isl_basic_set_remove_equalities(bset, &T, NULL);

  v = isl_vec_mat_product(v, isl_mat_copy(T));

  if (!v)

    goto error;

  res = isl_basic_set_solve_ilp(bset, max, v->el, opt, sol_p);

  isl_vec_free(v);

  if (res == isl_lp_ok && 
sol_p3.01k
) {

    *sol_p = isl_mat_vec_product(T, *sol_p);

    if (!*sol_p)

      res = isl_lp_error;

  } else

    isl_mat_free(T);

  isl_basic_set_free(bset);

  return res;

error:

  isl_mat_free(T);

  isl_basic_set_free(bset);

  return isl_lp_error;

}

/* Find an integer point in "bset" that minimizes (or maximizes if max is set)

 * f (if any).

 * If sol_p is not NULL then the integer point is returned in *sol_p.

 * The optimal value of f is returned in *opt.

 *

 * If there is any equality among the points in "bset", then we first

 * project it out.  Otherwise, we continue with solve_ilp above.

 */

enum isl_lp_result isl_basic_set_solve_ilp(__isl_keep isl_basic_set *bset,

  int max, isl_int *f, isl_int *opt, __isl_give isl_vec **sol_p)

{

  unsigned dim;

  enum isl_lp_result res;

  if (!bset)

    return isl_lp_error;

  if (sol_p)

    *sol_p = NULL;

  isl_assert(bset->ctx, isl_basic_set_n_param(bset) == 0,

    return isl_lp_error);

  if (isl_basic_set_plain_is_empty(bset))

    return isl_lp_empty;

  if (bset->n_eq)

    return solve_ilp_with_eq(bset, max, f, opt, sol_p);

  dim = isl_basic_set_total_dim(bset);

  if (max)

    isl_seq_neg(f, f, 1 + dim);

  res = solve_ilp(bset, f, opt, sol_p);

  if (max) {

    isl_seq_neg(f, f, 1 + dim);

    isl_int_neg(*opt, *opt);

  }

  return res;

}

static enum isl_lp_result basic_set_opt(__isl_keep isl_basic_set *bset, int max,

  __isl_keep isl_aff *obj, isl_int *opt)

{

  enum isl_lp_result res;

  if (!obj)

    return isl_lp_error;

  bset = isl_basic_set_copy(bset);

  bset = isl_basic_set_underlying_set(bset);

  res = isl_basic_set_solve_ilp(bset, max, obj->v->el + 1, opt, NULL);

  isl_basic_set_free(bset);

  return res;

}

static __isl_give isl_mat *extract_divs(__isl_keep isl_basic_set *bset)

{

  int i;

  isl_ctx *ctx = isl_basic_set_get_ctx(bset);

  isl_mat *div;

  div = isl_mat_alloc(ctx, bset->n_div,

          1 + 1 + isl_basic_set_total_dim(bset));

  if (!div)

    return NULL;

  
for (i = 0; 80
i < bset->n_div; 
++i80
)

    isl_seq_cpy(div->row[i], bset->div[i], div->n_col);

  return div;

}

enum isl_lp_result isl_basic_set_opt(__isl_keep isl_basic_set *bset, int max,

  __isl_keep isl_aff *obj, isl_int *opt)

{

  int *exp1 = NULL;

  int *exp2 = NULL;

  isl_ctx *ctx;

  isl_mat *bset_div = NULL;

  isl_mat *div = NULL;

  enum isl_lp_result res;

  int bset_n_div, obj_n_div;

  if (!bset || !obj)

    return isl_lp_error;

  ctx = isl_aff_get_ctx(obj);

  if (!isl_space_is_equal(bset->dim, obj->ls->dim))

    
isl_die0
(ctx, isl_error_invalid,

      "spaces don't match", return isl_lp_error);

  if (!isl_int_is_one(obj->v->el[0]))

    
isl_die0
(ctx, isl_error_unsupported,

      "expecting integer affine expression",

      return isl_lp_error);

  bset_n_div = isl_basic_set_dim(bset, isl_dim_div);

  obj_n_div = isl_aff_dim(obj, isl_dim_div);

  if (bset_n_div == 0 && 
obj_n_div == 03.49k
)

    return basic_set_opt(bset, max, obj, opt);

  bset = isl_basic_set_copy(bset);

  obj = isl_aff_copy(obj);

  bset_div = extract_divs(bset);

  exp1 = isl_alloc_array(ctx, int, bset_n_div);

  exp2 = isl_alloc_array(ctx, int, obj_n_div);

  if (!bset_div || (bset_n_div && !exp1) || (obj_n_div && !exp2))

    goto error;

  div = isl_merge_divs(bset_div, obj->ls->div, exp1, exp2);

  bset = isl_basic_set_expand_divs(bset, isl_mat_copy(div), exp1);

  obj = isl_aff_expand_divs(obj, isl_mat_copy(div), exp2);

  res = basic_set_opt(bset, max, obj, opt);

  isl_mat_free(bset_div);

  isl_mat_free(div);

  free(exp1);

  free(exp2);

  isl_basic_set_free(bset);

  isl_aff_free(obj);

  return res;

error:

  isl_mat_free(div);

  isl_mat_free(bset_div);

  free(exp1);

  free(exp2);

  isl_basic_set_free(bset);

  isl_aff_free(obj);

  return isl_lp_error;

}

/* Compute the minimum (maximum if max is set) of the integer affine

 * expression obj over the points in set and put the result in *opt.

 *

 * The parameters are assumed to have been aligned.

 */

static enum isl_lp_result isl_set_opt_aligned(__isl_keep isl_set *set, int max,

  __isl_keep isl_aff *obj, isl_int *opt)

{

  int i;

  enum isl_lp_result res;

  int empty = 1;

  isl_int opt_i;

  if (!set || !obj)

    return isl_lp_error;

  if (set->n == 0)

    return isl_lp_empty;

  res = isl_basic_set_opt(set->p[0], max, obj, opt);

  if (res == isl_lp_error || res == isl_lp_unbounded)

    return res;

  if (set->n == 1)

    return res;

  if (res == isl_lp_ok)

    empty = 0;

  isl_int_init(opt_i);

  for (i = 1; i < set->n; 
++i786
) {

    res = isl_basic_set_opt(set->p[i], max, obj, &opt_i);

    if (res == isl_lp_error || res == isl_lp_unbounded) {

      isl_int_clear(opt_i);

      return res;

    }

    if (res == isl_lp_empty)

      continue;

    empty = 0;

    if (max ? 
isl_int_gt784
(opt_i, *opt) : 
isl_int_lt1
(opt_i, *opt))

      
isl_int_set1
(*opt, opt_i);

  }

  isl_int_clear(opt_i);

  return empty ? 
isl_lp_empty0
 : isl_lp_ok;

}

/* Compute the minimum (maximum if max is set) of the integer affine

 * expression obj over the points in set and put the result in *opt.

 */

enum isl_lp_result isl_set_opt(__isl_keep isl_set *set, int max,

  __isl_keep isl_aff *obj, isl_int *opt)

{

  enum isl_lp_result res;

  isl_bool aligned;

  if (!set || !obj)

    return isl_lp_error;

  aligned = isl_set_space_has_equal_params(set, obj->ls->dim);

  if (aligned < 0)

    return isl_lp_error;

  if (aligned)

    return isl_set_opt_aligned(set, max, obj, opt);

  set = isl_set_copy(set);

  obj = isl_aff_copy(obj);

  set = isl_set_align_params(set, isl_aff_get_domain_space(obj));

  obj = isl_aff_align_params(obj, isl_set_get_space(set));

  res = isl_set_opt_aligned(set, max, obj, opt);

  isl_set_free(set);

  isl_aff_free(obj);

  return res;

}

/* Convert the result of a function that returns an isl_lp_result

 * to an isl_val.  The numerator of "v" is set to the optimal value

 * if lp_res is isl_lp_ok.  "max" is set if a maximum was computed.

 *

 * Return "v" with denominator set to 1 if lp_res is isl_lp_ok.

 * Return NULL on error.

 * Return a NaN if lp_res is isl_lp_empty.

 * Return infinity or negative infinity if lp_res is isl_lp_unbounded,

 * depending on "max".

 */

static __isl_give isl_val *convert_lp_result(enum isl_lp_result lp_res,

  __isl_take isl_val *v, int max)

{

  isl_ctx *ctx;

  if (lp_res == isl_lp_ok) {

    isl_int_set_si(v->d, 1);

    return isl_val_normalize(v);

  }

  ctx = isl_val_get_ctx(v);

  isl_val_free(v);

  if (lp_res == isl_lp_error)

    return NULL;

  if (lp_res == isl_lp_empty)

    return isl_val_nan(ctx);

  if (max)

    return isl_val_infty(ctx);

  else

    return isl_val_neginfty(ctx);

}

/* Return the minimum (maximum if max is set) of the integer affine

 * expression "obj" over the points in "bset".

 *

 * Return infinity or negative infinity if the optimal value is unbounded and

 * NaN if "bset" is empty.

 *

 * Call isl_basic_set_opt and translate the results.

 */

__isl_give isl_val *isl_basic_set_opt_val(__isl_keep isl_basic_set *bset,

  int max, __isl_keep isl_aff *obj)

{

  isl_ctx *ctx;

  isl_val *res;

  enum isl_lp_result lp_res;

  if (!bset || !obj)

    return NULL;

  ctx = isl_aff_get_ctx(obj);

  res = isl_val_alloc(ctx);

  if (!res)

    return NULL;

  lp_res = isl_basic_set_opt(bset, max, obj, &res->n);

  return convert_lp_result(lp_res, res, max);

}

/* Return the maximum of the integer affine

 * expression "obj" over the points in "bset".

 *

 * Return infinity or negative infinity if the optimal value is unbounded and

 * NaN if "bset" is empty.

 */

__isl_give isl_val *isl_basic_set_max_val(__isl_keep isl_basic_set *bset,

  __isl_keep isl_aff *obj)

{

  return isl_basic_set_opt_val(bset, 1, obj);

}

/* Return the minimum (maximum if max is set) of the integer affine

 * expression "obj" over the points in "set".

 *

 * Return infinity or negative infinity if the optimal value is unbounded and

 * NaN if "set" is empty.

 *

 * Call isl_set_opt and translate the results.

 */

__isl_give isl_val *isl_set_opt_val(__isl_keep isl_set *set, int max,

  __isl_keep isl_aff *obj)

{

  isl_ctx *ctx;

  isl_val *res;

  enum isl_lp_result lp_res;

  if (!set || !obj)

    return NULL;

  ctx = isl_aff_get_ctx(obj);

  res = isl_val_alloc(ctx);

  if (!res)

    return NULL;

  lp_res = isl_set_opt(set, max, obj, &res->n);

  return convert_lp_result(lp_res, res, max);

}

/* Return the minimum of the integer affine

 * expression "obj" over the points in "set".

 *

 * Return infinity or negative infinity if the optimal value is unbounded and

 * NaN if "set" is empty.

 */

__isl_give isl_val *isl_set_min_val(__isl_keep isl_set *set,

  __isl_keep isl_aff *obj)

{

  return isl_set_opt_val(set, 0, obj);

}

/* Return the maximum of the integer affine

 * expression "obj" over the points in "set".

 *

 * Return infinity or negative infinity if the optimal value is unbounded and

 * NaN if "set" is empty.

 */

__isl_give isl_val *isl_set_max_val(__isl_keep isl_set *set,

  __isl_keep isl_aff *obj)

{

  return isl_set_opt_val(set, 1, obj);

}

/* Return the optimum (min or max depending on "max") of "v1" and "v2",

 * where either may be NaN, signifying an uninitialized value.

 * That is, if either is NaN, then return the other one.

 */

static __isl_give isl_val *val_opt(__isl_take isl_val *v1,

  __isl_take isl_val *v2, int max)

{

  if (!v1 || !v2)

    goto error;

  if (isl_val_is_nan(v1)) {

    isl_val_free(v1);

    return v2;

  }

  if (isl_val_is_nan(v2)) {

    isl_val_free(v2);

    return v1;

  }

  if (max)

    return isl_val_max(v1, v2);

  else

    return isl_val_min(v1, v2);

error:

  isl_val_free(v1);

  isl_val_free(v2);

  return NULL;

}

/* Internal data structure for isl_set_opt_pw_aff.

 *

 * "max" is set if the maximum should be computed.

 * "set" is the set over which the optimum should be computed.

 * "res" contains the current optimum and is initialized to NaN.

 */

struct isl_set_opt_data {

  int max;

  isl_set *set;

  isl_val *res;

};

/* Update the optimum in data->res with respect to the affine function

 * "aff" defined over "set".

 */

static isl_stat piece_opt(__isl_take isl_set *set, __isl_take isl_aff *aff,

  void *user)

{

  struct isl_set_opt_data *data = user;

  isl_val *opt;

  set = isl_set_intersect(set, isl_set_copy(data->set));

  opt = isl_set_opt_val(set, data->max, aff);

  isl_set_free(set);

  isl_aff_free(aff);

  data->res = val_opt(data->res, opt, data->max);

  if (!data->res)

    return isl_stat_error;

  return isl_stat_ok;

}

/* Return the minimum (maximum if "max" is set) of the integer piecewise affine

 * expression "obj" over the points in "set".

 *

 * Return infinity or negative infinity if the optimal value is unbounded and

 * NaN if the intersection of "set" with the domain of "obj" is empty.

 *

 * Initialize the result to NaN and then update it for each of the pieces

 * in "obj".

 */

static __isl_give isl_val *isl_set_opt_pw_aff(__isl_keep isl_set *set, int max,

  __isl_keep isl_pw_aff *obj)

{

  struct isl_set_opt_data data = { max, set };

  data.res = isl_val_nan(isl_set_get_ctx(set));

  if (isl_pw_aff_foreach_piece(obj, &piece_opt, &data) < 0)

    return isl_val_free(data.res);

  return data.res;

}

/* Internal data structure for isl_union_set_opt_union_pw_aff.

 *

 * "max" is set if the maximum should be computed.

 * "obj" is the objective function that needs to be optimized.

 * "res" contains the current optimum and is initialized to NaN.

 */

struct isl_union_set_opt_data {

  int max;

  isl_union_pw_aff *obj;

  isl_val *res;

};

/* Update the optimum in data->res with the optimum over "set".

 * Do so by first extracting the matching objective function

 * from data->obj.

 */

static isl_stat set_opt(__isl_take isl_set *set, void *user)

{

  struct isl_union_set_opt_data *data = user;

  isl_space *space;

  isl_pw_aff *pa;

  isl_val *opt;

  space = isl_set_get_space(set);

  space = isl_space_from_domain(space);

  space = isl_space_add_dims(space, isl_dim_out, 1);

  pa = isl_union_pw_aff_extract_pw_aff(data->obj, space);

  opt = isl_set_opt_pw_aff(set, data->max, pa);

  isl_pw_aff_free(pa);

  isl_set_free(set);

  data->res = val_opt(data->res, opt, data->max);

  if (!data->res)

    return isl_stat_error;

  return isl_stat_ok;

}

/* Return the minimum (maximum if "max" is set) of the integer piecewise affine

 * expression "obj" over the points in "uset".

 *

 * Return infinity or negative infinity if the optimal value is unbounded and

 * NaN if the intersection of "uset" with the domain of "obj" is empty.

 *

 * Initialize the result to NaN and then update it for each of the sets

 * in "uset".

 */

static __isl_give isl_val *isl_union_set_opt_union_pw_aff(

  __isl_keep isl_union_set *uset, int max,

  __isl_keep isl_union_pw_aff *obj)

{

  struct isl_union_set_opt_data data = { max, obj };

  data.res = isl_val_nan(isl_union_set_get_ctx(uset));

  if (isl_union_set_foreach_set(uset, &set_opt, &data) < 0)

    return isl_val_free(data.res);

  return data.res;

}

/* Return a list of minima (maxima if "max" is set) over the points in "uset"

 * for each of the expressions in "obj".

 *

 * An element in the list is infinity or negative infinity if the optimal

 * value of the corresponding expression is unbounded and

 * NaN if the intersection of "uset" with the domain of the expression

 * is empty.

 *

 * Iterate over all the expressions in "obj" and collect the results.

 */

static __isl_give isl_multi_val *isl_union_set_opt_multi_union_pw_aff(

  __isl_keep isl_union_set *uset, int max,

  __isl_keep isl_multi_union_pw_aff *obj)

{

  int i, n;

  isl_multi_val *mv;

  if (!uset || !obj)

    return NULL;

  n = isl_multi_union_pw_aff_dim(obj, isl_dim_set);

  mv = isl_multi_val_zero(isl_multi_union_pw_aff_get_space(obj));

  for (i = 0; i < n; ++i) {

    isl_val *v;

    isl_union_pw_aff *upa;

    upa = isl_multi_union_pw_aff_get_union_pw_aff(obj, i);

    v = isl_union_set_opt_union_pw_aff(uset, max, upa);

    isl_union_pw_aff_free(upa);

    mv = isl_multi_val_set_val(mv, i, v);

  }

  return mv;

}

/* Return a list of minima over the points in "uset"

 * for each of the expressions in "obj".

 *

 * An element in the list is infinity or negative infinity if the optimal

 * value of the corresponding expression is unbounded and

 * NaN if the intersection of "uset" with the domain of the expression

 * is empty.

 */

__isl_give isl_multi_val *isl_union_set_min_multi_union_pw_aff(

  __isl_keep isl_union_set *uset, __isl_keep isl_multi_union_pw_aff *obj)

{

  return isl_union_set_opt_multi_union_pw_aff(uset, 0, obj);

}

/* Return the maximal value attained by the given set dimension,

 * independently of the parameter values and of any other dimensions.

 *

 * Return infinity if the optimal value is unbounded and

 * NaN if "bset" is empty.

 */

__isl_give isl_val *isl_basic_set_dim_max_val(__isl_take isl_basic_set *bset,

  int pos)

{

  isl_local_space *ls;

  isl_aff *obj;

  isl_val *v;

  if (!bset)

    return NULL;

  if (pos < 0 || pos >= isl_basic_set_dim(bset, isl_dim_set))

    isl_die(isl_basic_set_get_ctx(bset), isl_error_invalid,

      "position out of bounds", goto error);

  ls = isl_local_space_from_space(isl_basic_set_get_space(bset));

  obj = isl_aff_var_on_domain(ls, isl_dim_set, pos);

  v = isl_basic_set_max_val(bset, obj);

  isl_aff_free(obj);

  isl_basic_set_free(bset);

  return v;

error:

  isl_basic_set_free(bset);

  return NULL;

}