+/*
+ * Copyright 2008-2009 Katholieke Universiteit Leuven
+ * Copyright 2010 INRIA Saclay
+ *
+ * Use of this software is governed by the GNU LGPLv2.1 license
+ *
+ * Written by Sven Verdoolaege, K.U.Leuven, Departement
+ * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
+ * and INRIA Saclay - Ile-de-France, Parc Club Orsay Universite,
+ * ZAC des vignes, 4 rue Jacques Monod, 91893 Orsay, France
+ */
+
+#include <isl_ctx_private.h>
#include "isl_map_private.h"
-#include "isl_seq.h"
+#include <isl/seq.h>
#include "isl_tab.h"
#include "isl_sample.h"
+#include <isl_mat_private.h>
/*
* The implementation of parametric integer linear programming in this file
* The strategy used for obtaining a feasible solution is different
* from the one used in isl_tab.c. In particular, in isl_tab.c,
* upon finding a constraint that is not yet satisfied, we pivot
- * in a row that increases the constant term of row holding the
+ * in a row that increases the constant term of the row holding the
* constraint, making sure the sample solution remains feasible
* for all the constraints it already satisfied.
* Here, we always pivot in the row holding the constraint,
* then the initial sample value may be chosen equal to zero.
* However, we will not make this assumption. Instead, we apply
* the "big parameter" trick. Any variable x is then not directly
- * used in the tableau, but instead it its represented by another
+ * used in the tableau, but instead it is represented by another
* variable x' = M + x, where M is an arbitrarily large (positive)
* value. x' is therefore always non-negative, whatever the value of x.
- * Taking as initial smaple value x' = 0 corresponds to x = -M,
+ * Taking as initial sample value x' = 0 corresponds to x = -M,
* which is always smaller than any possible value of x.
*
* The big parameter trick is used in the main tableau and
/* return index of a div that corresponds to "div" */
int (*get_div)(struct isl_context *context, struct isl_tab *tab,
struct isl_vec *div);
- /* add div "div" to context and return index and non-negativity */
- int (*add_div)(struct isl_context *context, struct isl_vec *div,
- int *nonneg);
+ /* add div "div" to context and return non-negativity */
+ int (*add_div)(struct isl_context *context, struct isl_vec *div);
int (*detect_equalities)(struct isl_context *context,
struct isl_tab *tab);
/* return row index of "best" split */
isl_seq_clr(mat->row[1 + row], mat->n_col);
if (!tab->var[i].is_row) {
- /* no unbounded */
- isl_assert(mat->ctx, !tab->M, goto error2);
+ if (tab->M)
+ isl_die(mat->ctx, isl_error_invalid,
+ "unbounded optimum", goto error2);
continue;
}
r = tab->var[i].index;
- /* no unbounded */
- if (tab->M)
- isl_assert(mat->ctx, isl_int_eq(tab->mat->row[r][2],
- tab->mat->row[r][0]),
- goto error2);
+ if (tab->M &&
+ isl_int_ne(tab->mat->row[r][2], tab->mat->row[r][0]))
+ isl_die(mat->ctx, isl_error_invalid,
+ "unbounded optimum", goto error2);
isl_int_gcd(m, mat->row[0][0], tab->mat->row[r][0]);
isl_int_divexact(m, tab->mat->row[r][0], m);
scale_rows(mat, m, 1 + row);
error:
isl_basic_set_free(bset);
isl_mat_free(mat);
- sol_free(sol);
+ sol->error = 1;
}
struct isl_sol_map {
static void sol_map_free(struct isl_sol_map *sol_map)
{
+ if (!sol_map)
+ return;
if (sol_map->sol.context)
sol_map->sol.context->op->free(sol_map->sol.context);
isl_map_free(sol_map->map);
sol->empty = isl_set_grow(sol->empty, 1);
bset = isl_basic_set_simplify(bset);
bset = isl_basic_set_finalize(bset);
- sol->empty = isl_set_add(sol->empty, isl_basic_set_copy(bset));
+ sol->empty = isl_set_add_basic_set(sol->empty, isl_basic_set_copy(bset));
if (!sol->empty)
goto error;
isl_basic_set_free(bset);
sol_map_add_empty((struct isl_sol_map *)sol, bset);
}
+/* Add bset to sol's empty, but only if we are actually collecting
+ * the empty set.
+ */
+static void sol_map_add_empty_if_needed(struct isl_sol_map *sol,
+ struct isl_basic_set *bset)
+{
+ if (sol->empty)
+ sol_map_add_empty(sol, bset);
+ else
+ isl_basic_set_free(bset);
+}
+
/* Given a basic map "dom" that represents the context and an affine
* matrix "M" that maps the dimensions of the context to the
* output variables, construct a basic map with the same parameters
bmap = isl_basic_map_simplify(bmap);
bmap = isl_basic_map_finalize(bmap);
sol->map = isl_map_grow(sol->map, 1);
- sol->map = isl_map_add(sol->map, bmap);
+ sol->map = isl_map_add_basic_map(sol->map, bmap);
if (!sol->map)
goto error;
isl_basic_set_free(dom);
}
/* Return the first known violated constraint, i.e., a non-negative
- * contraint that currently has an either obviously negative value
+ * constraint that currently has an either obviously negative value
* or a previously determined to be negative value.
*
* If any constraint has a negative coefficient for the big parameter,
for (row = tab->n_redundant; row < tab->n_row; ++row) {
if (!isl_tab_var_from_row(tab, row)->is_nonneg)
continue;
- if (isl_int_is_neg(tab->mat->row[row][2]))
- return row;
+ if (!isl_int_is_neg(tab->mat->row[row][2]))
+ continue;
+ if (tab->row_sign)
+ tab->row_sign[row] = isl_tab_row_neg;
+ return row;
}
for (row = tab->n_redundant; row < tab->n_row; ++row) {
if (!isl_tab_var_from_row(tab, row)->is_nonneg)
return -1;
}
+/* Check whether the invariant that all columns are lexico-positive
+ * is satisfied. This function is not called from the current code
+ * but is useful during debugging.
+ */
+static void check_lexpos(struct isl_tab *tab)
+{
+ unsigned off = 2 + tab->M;
+ int col;
+ int var;
+ int row;
+
+ for (col = tab->n_dead; col < tab->n_col; ++col) {
+ if (tab->col_var[col] >= 0 &&
+ (tab->col_var[col] < tab->n_param ||
+ tab->col_var[col] >= tab->n_var - tab->n_div))
+ continue;
+ for (var = tab->n_param; var < tab->n_var - tab->n_div; ++var) {
+ if (!tab->var[var].is_row) {
+ if (tab->var[var].index == col)
+ break;
+ else
+ continue;
+ }
+ row = tab->var[var].index;
+ if (isl_int_is_zero(tab->mat->row[row][off + col]))
+ continue;
+ if (isl_int_is_pos(tab->mat->row[row][off + col]))
+ break;
+ fprintf(stderr, "lexneg column %d (row %d)\n",
+ col, row);
+ }
+ if (var >= tab->n_var - tab->n_div)
+ fprintf(stderr, "zero column %d\n", col);
+ }
+}
+
/* Resolve all known or obviously violated constraints through pivoting.
* In particular, as long as we can find any violated constraint, we
- * look for a pivoting column that would result in the lexicographicallly
+ * look for a pivoting column that would result in the lexicographically
* smallest increment in the sample point. If there is no such column
* then the tableau is infeasible.
*/
return tab;
while ((row = first_neg(tab)) != -1) {
col = lexmin_pivot_col(tab, row);
- if (col >= tab->n_col)
- return isl_tab_mark_empty(tab);
+ if (col >= tab->n_col) {
+ if (isl_tab_mark_empty(tab) < 0)
+ goto error;
+ return tab;
+ }
if (col < 0)
goto error;
if (isl_tab_pivot(tab, row, col) < 0)
if (isl_tab_kill_col(tab, i) < 0)
goto error;
tab->n_eq++;
-
- tab = restore_lexmin(tab);
}
return tab;
row = tab->con[r1].index;
if (is_constant(tab, row)) {
if (!isl_int_is_zero(tab->mat->row[row][1]) ||
- (tab->M && !isl_int_is_zero(tab->mat->row[row][2])))
- return isl_tab_mark_empty(tab);
+ (tab->M && !isl_int_is_zero(tab->mat->row[row][2]))) {
+ if (isl_tab_mark_empty(tab) < 0)
+ goto error;
+ return tab;
+ }
if (isl_tab_rollback(tab, snap) < 0)
goto error;
return tab;
} else if (!tab->con[r2].is_row) {
if (isl_tab_kill_col(tab, tab->con[r2].index) < 0)
goto error;
- } else if (isl_int_is_zero(tab->mat->row[tab->con[r1].index][1])) {
- unsigned off = 2 + tab->M;
- int i;
- int row = tab->con[r1].index;
- i = isl_seq_first_non_zero(tab->mat->row[row]+off+tab->n_dead,
- tab->n_col - tab->n_dead);
- if (i != -1) {
- if (isl_tab_pivot(tab, row, tab->n_dead + i) < 0)
- goto error;
- if (isl_tab_kill_col(tab, tab->n_dead + i) < 0)
- goto error;
- }
}
- if (tab->bset) {
- tab->bset = isl_basic_set_add_ineq(tab->bset, eq);
- if (isl_tab_push(tab, isl_tab_undo_bset_ineq) < 0)
+ if (tab->bmap) {
+ tab->bmap = isl_basic_map_add_ineq(tab->bmap, eq);
+ if (isl_tab_push(tab, isl_tab_undo_bmap_ineq) < 0)
goto error;
isl_seq_neg(eq, eq, 1 + tab->n_var);
- tab->bset = isl_basic_set_add_ineq(tab->bset, eq);
+ tab->bmap = isl_basic_map_add_ineq(tab->bmap, eq);
isl_seq_neg(eq, eq, 1 + tab->n_var);
- if (isl_tab_push(tab, isl_tab_undo_bset_ineq) < 0)
+ if (isl_tab_push(tab, isl_tab_undo_bmap_ineq) < 0)
goto error;
- if (!tab->bset)
+ if (!tab->bmap)
goto error;
}
if (!tab)
return NULL;
- if (tab->bset) {
- tab->bset = isl_basic_set_add_ineq(tab->bset, ineq);
- if (isl_tab_push(tab, isl_tab_undo_bset_ineq) < 0)
+ if (tab->bmap) {
+ tab->bmap = isl_basic_map_add_ineq(tab->bmap, ineq);
+ if (isl_tab_push(tab, isl_tab_undo_bmap_ineq) < 0)
goto error;
- if (!tab->bset)
+ if (!tab->bmap)
goto error;
}
r = isl_tab_add_row(tab, ineq);
#define I_PAR 1 << 1
#define I_VAR 1 << 2
-/* Check for first (non-parameter) variable that is non-integer and
- * therefore requires a cut.
+/* Check for next (non-parameter) variable after "var" (first if var == -1)
+ * that is non-integer and therefore requires a cut and return
+ * the index of the variable.
* For parametric tableaus, there are three parts in a row,
* the constant, the coefficients of the parameters and the rest.
* For each part, we check whether the coefficients in that part
* current sample value is integral and no cut is required
* (irrespective of whether the variable part is integral).
*/
-static int first_non_integer(struct isl_tab *tab, int *f)
+static int next_non_integer_var(struct isl_tab *tab, int var, int *f)
{
- int i;
+ var = var < 0 ? tab->n_param : var + 1;
- for (i = tab->n_param; i < tab->n_var - tab->n_div; ++i) {
+ for (; var < tab->n_var - tab->n_div; ++var) {
int flags = 0;
int row;
- if (!tab->var[i].is_row)
+ if (!tab->var[var].is_row)
continue;
- row = tab->var[i].index;
+ row = tab->var[var].index;
if (integer_constant(tab, row))
ISL_FL_SET(flags, I_CST);
if (integer_parameter(tab, row))
if (integer_variable(tab, row))
ISL_FL_SET(flags, I_VAR);
*f = flags;
- return row;
+ return var;
}
return -1;
}
+/* Check for first (non-parameter) variable that is non-integer and
+ * therefore requires a cut and return the corresponding row.
+ * For parametric tableaus, there are three parts in a row,
+ * the constant, the coefficients of the parameters and the rest.
+ * For each part, we check whether the coefficients in that part
+ * are all integral and if so, set the corresponding flag in *f.
+ * If the constant and the parameter part are integral, then the
+ * current sample value is integral and no cut is required
+ * (irrespective of whether the variable part is integral).
+ */
+static int first_non_integer_row(struct isl_tab *tab, int *f)
+{
+ int var = next_non_integer_var(tab, -1, f);
+
+ return var < 0 ? -1 : tab->var[var].index;
+}
+
/* Add a (non-parametric) cut to cut away the non-integral sample
* value of the given row.
*
* sample point is obtained or until the tableau is determined
* to be integer infeasible.
* As long as there is any non-integer value in the sample point,
- * we add an appropriate cut, if possible and resolve the violated
- * cut constraint using restore_lexmin.
+ * we add appropriate cuts, if possible, for each of these
+ * non-integer values and then resolve the violated
+ * cut constraints using restore_lexmin.
* If one of the corresponding rows is equal to an integral
* combination of variables/constraints plus a non-integral constant,
- * then there is no way to obtain an integer point an we return
+ * then there is no way to obtain an integer point and we return
* a tableau that is marked empty.
*/
static struct isl_tab *cut_to_integer_lexmin(struct isl_tab *tab)
{
+ int var;
int row;
int flags;
if (tab->empty)
return tab;
- while ((row = first_non_integer(tab, &flags)) != -1) {
- if (ISL_FL_ISSET(flags, I_VAR))
- return isl_tab_mark_empty(tab);
- row = add_cut(tab, row);
- if (row < 0)
- goto error;
+ while ((var = next_non_integer_var(tab, -1, &flags)) != -1) {
+ do {
+ if (ISL_FL_ISSET(flags, I_VAR)) {
+ if (isl_tab_mark_empty(tab) < 0)
+ goto error;
+ return tab;
+ }
+ row = tab->var[var].index;
+ row = add_cut(tab, row);
+ if (row < 0)
+ goto error;
+ } while ((var = next_non_integer_var(tab, var, &flags)) != -1);
tab = restore_lexmin(tab);
if (!tab || tab->empty)
break;
if (!tab)
return NULL;
- isl_assert(tab->mat->ctx, tab->bset, goto error);
+ isl_assert(tab->mat->ctx, tab->bmap, goto error);
isl_assert(tab->mat->ctx, tab->samples, goto error);
isl_assert(tab->mat->ctx, tab->samples->n_col == 1 + tab->n_var, goto error);
if (!tab)
return -1;
- isl_assert(tab->mat->ctx, tab->bset, return -1);
+ isl_assert(tab->mat->ctx, tab->bmap, return -1);
isl_assert(tab->mat->ctx, tab->samples, return -1);
isl_assert(tab->mat->ctx, tab->samples->n_col == 1 + tab->n_var, return -1);
return i < tab->n_sample;
}
-/* For a div d = floor(f/m), add the constraints
- *
- * f - m d >= 0
- * -(f-(m-1)) + m d >= 0
- *
- * Note that the second constraint is the negation of
- *
- * f - m d >= m
- */
-static void add_div_constraints(struct isl_context *context, unsigned div)
-{
- unsigned total;
- unsigned div_pos;
- struct isl_vec *ineq;
- struct isl_basic_set *bset;
-
- bset = context->op->peek_basic_set(context);
- if (!bset)
- goto error;
-
- total = isl_basic_set_total_dim(bset);
- div_pos = 1 + total - bset->n_div + div;
-
- ineq = ineq_for_div(bset, div);
- if (!ineq)
- goto error;
-
- context->op->add_ineq(context, ineq->el, 0, 0);
-
- isl_seq_neg(ineq->el, bset->div[div] + 1, 1 + total);
- isl_int_set(ineq->el[div_pos], bset->div[div][0]);
- isl_int_add(ineq->el[0], ineq->el[0], ineq->el[div_pos]);
- isl_int_sub_ui(ineq->el[0], ineq->el[0], 1);
-
- context->op->add_ineq(context, ineq->el, 0, 0);
-
- isl_vec_free(ineq);
-
- return;
-error:
- context->op->invalidate(context);
-}
-
-/* Add a div specifed by "div" to the tableau "tab" and return
- * the index of the new div. *nonneg is set to 1 if the div
- * is obviously non-negative.
+/* Add a div specified by "div" to the tableau "tab" and return
+ * 1 if the div is obviously non-negative.
*/
static int context_tab_add_div(struct isl_tab *tab, struct isl_vec *div,
- int *nonneg)
+ int (*add_ineq)(void *user, isl_int *), void *user)
{
int i;
int r;
- int k;
struct isl_mat *samples;
+ int nonneg;
- for (i = 0; i < tab->n_var; ++i) {
- if (isl_int_is_zero(div->el[2 + i]))
- continue;
- if (!tab->var[i].is_nonneg)
- break;
- }
- *nonneg = i == tab->n_var;
-
- if (isl_tab_extend_cons(tab, 3) < 0)
- return -1;
- if (isl_tab_extend_vars(tab, 1) < 0)
- return -1;
- r = isl_tab_allocate_var(tab);
+ r = isl_tab_add_div(tab, div, add_ineq, user);
if (r < 0)
return -1;
- if (*nonneg)
- tab->var[r].is_nonneg = 1;
+ nonneg = tab->var[r].is_nonneg;
tab->var[r].frozen = 1;
samples = isl_mat_extend(tab->samples,
samples->row[i][samples->n_col - 1], div->el[0]);
}
- tab->bset = isl_basic_set_extend_dim(tab->bset,
- isl_basic_set_get_dim(tab->bset), 1, 0, 2);
- k = isl_basic_set_alloc_div(tab->bset);
- if (k < 0)
- return -1;
- isl_seq_cpy(tab->bset->div[k], div->el, div->size);
- if (isl_tab_push(tab, isl_tab_undo_bset_div) < 0)
- return -1;
-
- return k;
+ return nonneg;
}
/* Add a div specified by "div" to both the main tableau and
struct isl_vec *div)
{
int r;
- int k;
int nonneg;
- k = context->op->add_div(context, div, &nonneg);
- if (k < 0)
+ if ((nonneg = context->op->add_div(context, div)) < 0)
goto error;
- add_div_constraints(context, k);
if (!context->op->is_ok(context))
goto error;
static int find_div(struct isl_tab *tab, isl_int *div, isl_int denom)
{
int i;
- unsigned total = isl_basic_set_total_dim(tab->bset);
+ unsigned total = isl_basic_map_total_dim(tab->bmap);
- for (i = 0; i < tab->bset->n_div; ++i) {
- if (isl_int_ne(tab->bset->div[i][0], denom))
+ for (i = 0; i < tab->bmap->n_div; ++i) {
+ if (isl_int_ne(tab->bmap->div[i][0], denom))
continue;
- if (!isl_seq_eq(tab->bset->div[i] + 1, div, total))
+ if (!isl_seq_eq(tab->bmap->div[i] + 1, div, 1 + total))
continue;
return i;
}
if (!tab->row_sign)
goto error;
}
- if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
- return isl_tab_mark_empty(tab);
+ if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY)) {
+ if (isl_tab_mark_empty(tab) < 0)
+ goto error;
+ return tab;
+ }
for (i = tab->n_param; i < tab->n_var - tab->n_div; ++i) {
tab->var[i].is_nonneg = 1;
if (!tab || tab->empty)
return tab;
}
+ if (bmap->n_eq)
+ tab = restore_lexmin(tab);
for (i = 0; i < bmap->n_ineq; ++i) {
if (max)
isl_seq_neg(bmap->ineq[i] + 1 + tab->n_param,
struct isl_tab_undo *snap2;
struct isl_vec *ineq = NULL;
int r = 0;
+ int ok;
if (!isl_tab_var_from_row(tab, split)->is_nonneg)
continue;
ineq = get_row_parameter_ineq(tab, split);
if (!ineq)
return -1;
- context_tab = isl_tab_add_ineq(context_tab, ineq->el);
+ ok = isl_tab_add_ineq(context_tab, ineq->el) >= 0;
isl_vec_free(ineq);
+ if (!ok)
+ return -1;
snap2 = isl_tab_snap(context_tab);
ineq = get_row_parameter_ineq(tab, row);
if (!ineq)
return -1;
- context_tab = isl_tab_add_ineq(context_tab, ineq->el);
+ ok = isl_tab_add_ineq(context_tab, ineq->el) >= 0;
isl_vec_free(ineq);
+ if (!ok)
+ return -1;
var = &context_tab->con[context_tab->n_con - 1];
if (!context_tab->empty &&
!isl_tab_min_at_most_neg_one(context_tab, var))
struct isl_context_lex *clex = (struct isl_context_lex *)context;
if (!clex->tab)
return NULL;
- return clex->tab->bset;
+ return isl_tab_peek_bset(clex->tab);
}
static struct isl_tab *context_lex_peek_tab(struct isl_context *context)
clex->tab = NULL;
}
+static int context_lex_add_ineq_wrap(void *user, isl_int *ineq)
+{
+ struct isl_context *context = (struct isl_context *)user;
+ context_lex_add_ineq(context, ineq, 0, 0);
+ return context->op->is_ok(context) ? 0 : -1;
+}
+
/* Check which signs can be obtained by "ineq" on all the currently
* active sample values. See row_sign for more information.
*/
int i;
int sgn;
isl_int tmp;
- int res = isl_tab_row_unknown;
+ enum isl_tab_row_sign res = isl_tab_row_unknown;
- isl_assert(tab->mat->ctx, tab->samples, return 0);
- isl_assert(tab->mat->ctx, tab->samples->n_col == 1 + tab->n_var, return 0);
+ isl_assert(tab->mat->ctx, tab->samples, return isl_tab_row_unknown);
+ isl_assert(tab->mat->ctx, tab->samples->n_col == 1 + tab->n_var,
+ return isl_tab_row_unknown);
isl_int_init(tmp);
for (i = tab->n_outside; i < tab->n_sample; ++i) {
return get_div(tab, context, div);
}
-static int context_lex_add_div(struct isl_context *context, struct isl_vec *div,
- int *nonneg)
+/* Add a div specified by "div" to the context tableau and return
+ * 1 if the div is obviously non-negative.
+ * context_tab_add_div will always return 1, because all variables
+ * in a isl_context_lex tableau are non-negative.
+ * However, if we are using a big parameter in the context, then this only
+ * reflects the non-negativity of the variable used to _encode_ the
+ * div, i.e., div' = M + div, so we can't draw any conclusions.
+ */
+static int context_lex_add_div(struct isl_context *context, struct isl_vec *div)
{
struct isl_context_lex *clex = (struct isl_context_lex *)context;
- return context_tab_add_div(clex->tab, div, nonneg);
+ int nonneg;
+ nonneg = context_tab_add_div(clex->tab, div,
+ context_lex_add_ineq_wrap, context);
+ if (nonneg < 0)
+ return -1;
+ if (clex->tab->M)
+ return 0;
+ return nonneg;
}
static int context_lex_detect_equalities(struct isl_context *context,
return -1;
r = best_split(tab, clex->tab);
- if (isl_tab_rollback(clex->tab, snap) < 0)
+ if (r >= 0 && isl_tab_rollback(clex->tab, snap) < 0)
return -1;
return r;
isl_seq_clr(ineq->el, ineq->size);
for (i = 0; i < context_tab->n_var; ++i) {
isl_int_set_si(ineq->el[1 + i], 1);
- context_tab = isl_tab_add_ineq(context_tab, ineq->el);
+ if (isl_tab_add_ineq(context_tab, ineq->el) < 0)
+ goto error;
var = &context_tab->con[context_tab->n_con - 1];
if (!context_tab->empty &&
!isl_tab_min_at_most_neg_one(context_tab, var)) {
struct isl_context_lex *clex = (struct isl_context_lex *)context;
struct isl_tab_undo *snap;
+ if (!tab)
+ return NULL;
+
snap = isl_tab_snap(clex->tab);
if (isl_tab_push_basis(clex->tab) < 0)
goto error;
tab = tab_for_lexmin((struct isl_basic_map *)bset, NULL, 1, 0);
if (!tab)
goto error;
- tab->bset = bset;
+ if (isl_tab_track_bset(tab, bset) < 0)
+ goto error;
tab = isl_tab_init_samples(tab);
return tab;
error:
struct isl_context *context, struct isl_tab *tab)
{
struct isl_context_gbr *cgbr = (struct isl_context_gbr *)context;
+ if (!tab)
+ return NULL;
return tab_detect_nonnegative_parameters(tab, cgbr->tab);
}
struct isl_context_gbr *cgbr = (struct isl_context_gbr *)context;
if (!cgbr->tab)
return NULL;
- return cgbr->tab->bset;
+ return isl_tab_peek_bset(cgbr->tab);
}
static struct isl_tab *context_gbr_peek_tab(struct isl_context *context)
{
int i, j;
struct isl_vec *cst;
- struct isl_basic_set *bset = cgbr->tab->bset;
+ struct isl_basic_set *bset = isl_tab_peek_bset(cgbr->tab);
unsigned dim = isl_basic_set_total_dim(bset);
cst = isl_vec_alloc(cgbr->tab->mat->ctx, bset->n_ineq);
static int use_shifted(struct isl_context_gbr *cgbr)
{
- return cgbr->tab->bset->n_eq == 0 && cgbr->tab->bset->n_div == 0;
+ return cgbr->tab->bmap->n_eq == 0 && cgbr->tab->bmap->n_div == 0;
}
static struct isl_vec *gbr_get_sample(struct isl_context_gbr *cgbr)
}
if (!cgbr->cone) {
- cgbr->cone = isl_tab_from_recession_cone(cgbr->tab->bset);
+ bset = isl_tab_peek_bset(cgbr->tab);
+ cgbr->cone = isl_tab_from_recession_cone(bset, 0);
if (!cgbr->cone)
return NULL;
- cgbr->cone->bset = isl_basic_set_dup(cgbr->tab->bset);
+ if (isl_tab_track_bset(cgbr->cone, isl_basic_set_dup(bset)) < 0)
+ return NULL;
}
- cgbr->cone = isl_tab_detect_implicit_equalities(cgbr->cone);
- if (!cgbr->cone)
+ if (isl_tab_detect_implicit_equalities(cgbr->cone) < 0)
return NULL;
if (cgbr->cone->n_dead == cgbr->cone->n_col) {
if (cgbr->tab->basis->n_col != 1 + cgbr->tab->n_var) {
isl_mat_free(cgbr->tab->basis);
cgbr->tab->basis = NULL;
- } else {
- cgbr->tab->n_zero = 0;
- cgbr->tab->n_unbounded = 0;
}
+ cgbr->tab->n_zero = 0;
+ cgbr->tab->n_unbounded = 0;
}
snap = isl_tab_snap(cgbr->tab);
return sample;
}
- cone = isl_basic_set_dup(cgbr->cone->bset);
+ cone = isl_basic_set_dup(isl_tab_peek_bset(cgbr->cone));
cone = drop_constant_terms(cone);
cone = isl_basic_set_update_from_tab(cone, cgbr->cone);
cone = isl_basic_set_underlying_set(cone);
cone = isl_basic_set_gauss(cone, NULL);
- bset = isl_basic_set_dup(cgbr->tab->bset);
+ bset = isl_basic_set_dup(isl_tab_peek_bset(cgbr->tab));
bset = isl_basic_set_update_from_tab(bset, cgbr->tab);
bset = isl_basic_set_underlying_set(bset);
bset = isl_basic_set_gauss(bset, NULL);
if (sample->size == 0) {
isl_vec_free(sample);
- cgbr->tab = isl_tab_mark_empty(cgbr->tab);
+ if (isl_tab_mark_empty(cgbr->tab) < 0)
+ goto error;
return;
}
if (isl_tab_extend_cons(tab, 2) < 0)
goto error;
- tab = isl_tab_add_eq(tab, eq);
+ if (isl_tab_add_eq(tab, eq) < 0)
+ goto error;
return tab;
error:
if (cgbr->cone && cgbr->cone->n_col != cgbr->cone->n_dead) {
if (isl_tab_extend_cons(cgbr->cone, 2) < 0)
goto error;
- cgbr->cone = isl_tab_add_eq(cgbr->cone, eq);
+ if (isl_tab_add_eq(cgbr->cone, eq) < 0)
+ goto error;
}
if (check) {
if (isl_tab_extend_cons(cgbr->tab, 1) < 0)
goto error;
- cgbr->tab = isl_tab_add_ineq(cgbr->tab, ineq);
+ if (isl_tab_add_ineq(cgbr->tab, ineq) < 0)
+ goto error;
if (cgbr->shifted && !cgbr->shifted->empty && use_shifted(cgbr)) {
int i;
unsigned dim;
- dim = isl_basic_set_total_dim(cgbr->tab->bset);
+ dim = isl_basic_map_total_dim(cgbr->tab->bmap);
if (isl_tab_extend_cons(cgbr->shifted, 1) < 0)
goto error;
isl_int_add(ineq[0], ineq[0], ineq[1 + i]);
}
- cgbr->shifted = isl_tab_add_ineq(cgbr->shifted, ineq);
+ if (isl_tab_add_ineq(cgbr->shifted, ineq) < 0)
+ goto error;
for (i = 0; i < dim; ++i) {
if (!isl_int_is_neg(ineq[1 + i]))
if (cgbr->cone && cgbr->cone->n_col != cgbr->cone->n_dead) {
if (isl_tab_extend_cons(cgbr->cone, 1) < 0)
goto error;
- cgbr->cone = isl_tab_add_ineq(cgbr->cone, ineq);
+ if (isl_tab_add_ineq(cgbr->cone, ineq) < 0)
+ goto error;
}
return;
cgbr->tab = NULL;
}
+static int context_gbr_add_ineq_wrap(void *user, isl_int *ineq)
+{
+ struct isl_context *context = (struct isl_context *)user;
+ context_gbr_add_ineq(context, ineq, 0, 0);
+ return context->op->is_ok(context) ? 0 : -1;
+}
+
static enum isl_tab_row_sign context_gbr_ineq_sign(struct isl_context *context,
isl_int *ineq, int strict)
{
if (!eq)
goto error;
- if (isl_tab_extend_cons(tab, (cgbr->tab->bset->n_ineq - first)/2) < 0)
+ if (isl_tab_extend_cons(tab, (cgbr->tab->bmap->n_ineq - first)/2) < 0)
goto error;
isl_seq_clr(eq->el + 1 + tab->n_param,
tab->n_var - tab->n_param - tab->n_div);
- for (i = first; i < cgbr->tab->bset->n_ineq; i += 2) {
+ for (i = first; i < cgbr->tab->bmap->n_ineq; i += 2) {
int j;
int r;
struct isl_tab_undo *snap;
snap = isl_tab_snap(tab);
- isl_seq_cpy(eq->el, cgbr->tab->bset->ineq[i], 1 + tab->n_param);
+ isl_seq_cpy(eq->el, cgbr->tab->bmap->ineq[i], 1 + tab->n_param);
isl_seq_cpy(eq->el + 1 + tab->n_var - tab->n_div,
- cgbr->tab->bset->ineq[i] + 1 + tab->n_param,
+ cgbr->tab->bmap->ineq[i] + 1 + tab->n_param,
tab->n_div);
r = isl_tab_add_row(tab, eq->el);
ctx = cgbr->tab->mat->ctx;
if (!cgbr->cone) {
- cgbr->cone = isl_tab_from_recession_cone(cgbr->tab->bset);
+ struct isl_basic_set *bset = isl_tab_peek_bset(cgbr->tab);
+ cgbr->cone = isl_tab_from_recession_cone(bset, 0);
if (!cgbr->cone)
goto error;
- cgbr->cone->bset = isl_basic_set_dup(cgbr->tab->bset);
+ if (isl_tab_track_bset(cgbr->cone, isl_basic_set_dup(bset)) < 0)
+ goto error;
}
- cgbr->cone = isl_tab_detect_implicit_equalities(cgbr->cone);
+ if (isl_tab_detect_implicit_equalities(cgbr->cone) < 0)
+ goto error;
- n_ineq = cgbr->tab->bset->n_ineq;
+ n_ineq = cgbr->tab->bmap->n_ineq;
cgbr->tab = isl_tab_detect_equalities(cgbr->tab, cgbr->cone);
- if (cgbr->tab && cgbr->tab->bset->n_ineq > n_ineq)
+ if (cgbr->tab && cgbr->tab->bmap->n_ineq > n_ineq)
propagate_equalities(cgbr, tab, n_ineq);
return 0;
return get_div(tab, context, div);
}
-static int context_gbr_add_div(struct isl_context *context, struct isl_vec *div,
- int *nonneg)
+static int context_gbr_add_div(struct isl_context *context, struct isl_vec *div)
{
struct isl_context_gbr *cgbr = (struct isl_context_gbr *)context;
if (cgbr->cone) {
if (isl_tab_allocate_var(cgbr->cone) <0)
return -1;
- cgbr->cone->bset = isl_basic_set_extend_dim(cgbr->cone->bset,
- isl_basic_set_get_dim(cgbr->cone->bset), 1, 0, 2);
- k = isl_basic_set_alloc_div(cgbr->cone->bset);
+ cgbr->cone->bmap = isl_basic_map_extend_dim(cgbr->cone->bmap,
+ isl_basic_map_get_dim(cgbr->cone->bmap), 1, 0, 2);
+ k = isl_basic_map_alloc_div(cgbr->cone->bmap);
if (k < 0)
return -1;
- isl_seq_cpy(cgbr->cone->bset->div[k], div->el, div->size);
- if (isl_tab_push(cgbr->cone, isl_tab_undo_bset_div) < 0)
+ isl_seq_cpy(cgbr->cone->bmap->div[k], div->el, div->size);
+ if (isl_tab_push(cgbr->cone, isl_tab_undo_bmap_div) < 0)
return -1;
}
- return context_tab_add_div(cgbr->tab, div, nonneg);
+ return context_tab_add_div(cgbr->tab, div,
+ context_gbr_add_ineq_wrap, context);
}
static int context_gbr_best_split(struct isl_context *context,
snap = isl_tab_snap(cgbr->tab);
r = best_split(tab, cgbr->tab);
- if (isl_tab_rollback(cgbr->tab, snap) < 0)
+ if (r >= 0 && isl_tab_rollback(cgbr->tab, snap) < 0)
return -1;
return r;
cgbr->tab = isl_tab_init_samples(cgbr->tab);
if (!cgbr->tab)
goto error;
- cgbr->tab->bset = isl_basic_set_cow(isl_basic_set_copy(dom));
- if (!cgbr->tab->bset)
+ if (isl_tab_track_bset(cgbr->tab,
+ isl_basic_set_cow(isl_basic_set_copy(dom))) < 0)
goto error;
check_gbr_integer_feasible(cgbr);
static struct isl_sol_map *sol_map_init(struct isl_basic_map *bmap,
struct isl_basic_set *dom, int track_empty, int max)
{
- struct isl_sol_map *sol_map;
+ struct isl_sol_map *sol_map = NULL;
- sol_map = isl_calloc_type(bset->ctx, struct isl_sol_map);
+ if (!bmap)
+ goto error;
+
+ sol_map = isl_calloc_type(bmap->ctx, struct isl_sol_map);
if (!sol_map)
goto error;
struct isl_sol *sol, int row)
{
struct isl_vec *ineq = NULL;
- int res = isl_tab_row_unknown;
+ enum isl_tab_row_sign res = isl_tab_row_unknown;
int critical;
int strict;
int row2;
return res;
error:
isl_vec_free(ineq);
- return 0;
+ return isl_tab_row_unknown;
}
static void find_solutions(struct isl_sol *sol, struct isl_tab *tab);
find_solutions(sol, tab);
- sol->context->op->restore(sol->context, saved);
+ if (!sol->error)
+ sol->context->op->restore(sol->context, saved);
return;
error:
sol->error = 1;
int empty;
void *saved;
- if (!sol->context)
+ if (!sol->context || sol->error)
goto error;
saved = sol->context->op->save(sol->context);
* coefficient are integral, then there is nothing that can be done
* and the tableau has no integral solution.
* If, on the other hand, one or more of the other columns have rational
- * coeffcients, but the parameter coefficients are all integral, then
+ * coefficients, but the parameter coefficients are all integral, then
* we can perform a regular (non-parametric) cut.
* Finally, if there is any parameter coefficient that is non-integral,
* then we need to involve the context tableau. There are two cases here.
for (; tab && !tab->empty; tab = restore_lexmin(tab)) {
int flags;
int row;
- int sgn;
+ enum isl_tab_row_sign sgn;
int split = -1;
int n_split = 0;
row = split;
isl_seq_neg(ineq->el, ineq->el, ineq->size);
isl_int_sub_ui(ineq->el[0], ineq->el[0], 1);
- context->op->add_ineq(context, ineq->el, 0, 1);
+ if (!sol->error)
+ context->op->add_ineq(context, ineq->el, 0, 1);
isl_vec_free(ineq);
if (sol->error)
goto error;
}
if (tab->rational)
break;
- row = first_non_integer(tab, &flags);
+ row = first_non_integer_row(tab, &flags);
if (row < 0)
break;
if (ISL_FL_ISSET(flags, I_PAR)) {
if (ISL_FL_ISSET(flags, I_VAR)) {
- tab = isl_tab_mark_empty(tab);
+ if (isl_tab_mark_empty(tab) < 0)
+ goto error;
break;
}
row = add_cut(tab, row);
if (d < 0)
goto error;
ineq = ineq_for_div(context->op->peek_basic_set(context), d);
+ if (!ineq)
+ goto error;
sol_inc_level(sol);
no_sol_in_strict(sol, tab, ineq);
isl_seq_neg(ineq->el, ineq->el, ineq->size);
if (sol->error || !context->op->is_ok(context))
goto error;
tab = set_row_cst_to_div(tab, row, d);
+ if (context->op->is_empty(context))
+ break;
} else
row = add_parametric_cut(tab, row, context);
if (row < 0)
return;
error:
isl_tab_free(tab);
- sol_free(sol);
+ sol->error = 1;
}
/* Compute the lexicographic minimum of the set represented by the main
{
int row;
+ if (!tab)
+ goto error;
+
sol->level = 0;
for (row = tab->n_redundant; row < tab->n_row; ++row) {
+ tab->n_param - (tab->n_var - tab->n_div);
eq = isl_vec_alloc(tab->mat->ctx, 1+tab->n_param+tab->n_div);
+ if (!eq)
+ goto error;
get_row_parameter_line(tab, row, eq->el);
isl_int_neg(eq->el[1 + p], tab->mat->row[row][0]);
eq = isl_vec_normalize(eq);
return;
error:
isl_tab_free(tab);
- sol_free(sol);
+ sol->error = 1;
}
static void sol_map_find_solutions(struct isl_sol_map *sol_map,
return NULL;
}
-/* Compute the lexicographic minimum (or maximum if "max" is set)
- * of "bmap" over the domain "dom" and return the result as a map.
- * If "empty" is not NULL, then *empty is assigned a set that
- * contains those parts of the domain where there is no solution.
- * If "bmap" is marked as rational (ISL_BASIC_MAP_RATIONAL),
- * then we compute the rational optimum. Otherwise, we compute
- * the integral optimum.
+/* Base case of isl_tab_basic_map_partial_lexopt, after removing
+ * some obvious symmetries.
*
- * We perform some preprocessing. As the PILP solver does not
- * handle implicit equalities very well, we first make sure all
- * the equalities are explicitly available.
- * We also make sure the divs in the domain are properly order,
+ * We make sure the divs in the domain are properly ordered,
* because they will be added one by one in the given order
* during the construction of the solution map.
*/
-struct isl_map *isl_tab_basic_map_partial_lexopt(
- struct isl_basic_map *bmap, struct isl_basic_set *dom,
- struct isl_set **empty, int max)
+static __isl_give isl_map *basic_map_partial_lexopt_base(
+ __isl_take isl_basic_map *bmap, __isl_take isl_basic_set *dom,
+ __isl_give isl_set **empty, int max)
{
+ isl_map *result = NULL;
struct isl_tab *tab;
- struct isl_map *result = NULL;
struct isl_sol_map *sol_map = NULL;
struct isl_context *context;
- struct isl_basic_map *eq;
-
- if (empty)
- *empty = NULL;
- if (!bmap || !dom)
- goto error;
-
- isl_assert(bmap->ctx,
- isl_basic_map_compatible_domain(bmap, dom), goto error);
-
- eq = isl_basic_map_copy(bmap);
- eq = isl_basic_map_intersect_domain(eq, isl_basic_set_copy(dom));
- eq = isl_basic_map_affine_hull(eq);
- bmap = isl_basic_map_intersect(bmap, eq);
if (dom->n_div) {
dom = isl_basic_set_order_divs(dom);
if (isl_basic_set_fast_is_empty(context->op->peek_basic_set(context)))
/* nothing */;
else if (isl_basic_map_fast_is_empty(bmap))
- sol_map_add_empty(sol_map,
- isl_basic_set_dup(context->op->peek_basic_set(context)));
+ sol_map_add_empty_if_needed(sol_map,
+ isl_basic_set_copy(context->op->peek_basic_set(context)));
else {
tab = tab_for_lexmin(bmap,
context->op->peek_basic_set(context), 1, max);
return NULL;
}
+/* Structure used during detection of parallel constraints.
+ * n_in: number of "input" variables: isl_dim_param + isl_dim_in
+ * n_out: number of "output" variables: isl_dim_out + isl_dim_div
+ * val: the coefficients of the output variables
+ */
+struct isl_constraint_equal_info {
+ isl_basic_map *bmap;
+ unsigned n_in;
+ unsigned n_out;
+ isl_int *val;
+};
+
+/* Check whether the coefficients of the output variables
+ * of the constraint in "entry" are equal to info->val.
+ */
+static int constraint_equal(const void *entry, const void *val)
+{
+ isl_int **row = (isl_int **)entry;
+ const struct isl_constraint_equal_info *info = val;
+
+ return isl_seq_eq((*row) + 1 + info->n_in, info->val, info->n_out);
+}
+
+/* Check whether "bmap" has a pair of constraints that have
+ * the same coefficients for the output variables.
+ * Note that the coefficients of the existentially quantified
+ * variables need to be zero since the existentially quantified
+ * of the result are usually not the same as those of the input.
+ * the isl_dim_out and isl_dim_div dimensions.
+ * If so, return 1 and return the row indices of the two constraints
+ * in *first and *second.
+ */
+static int parallel_constraints(__isl_keep isl_basic_map *bmap,
+ int *first, int *second)
+{
+ int i;
+ isl_ctx *ctx = isl_basic_map_get_ctx(bmap);
+ struct isl_hash_table *table = NULL;
+ struct isl_hash_table_entry *entry;
+ struct isl_constraint_equal_info info;
+ unsigned n_out;
+ unsigned n_div;
+
+ ctx = isl_basic_map_get_ctx(bmap);
+ table = isl_hash_table_alloc(ctx, bmap->n_ineq);
+ if (!table)
+ goto error;
+
+ info.n_in = isl_basic_map_dim(bmap, isl_dim_param) +
+ isl_basic_map_dim(bmap, isl_dim_in);
+ info.bmap = bmap;
+ n_out = isl_basic_map_dim(bmap, isl_dim_out);
+ n_div = isl_basic_map_dim(bmap, isl_dim_div);
+ info.n_out = n_out + n_div;
+ for (i = 0; i < bmap->n_ineq; ++i) {
+ uint32_t hash;
+
+ info.val = bmap->ineq[i] + 1 + info.n_in;
+ if (isl_seq_first_non_zero(info.val, n_out) < 0)
+ continue;
+ if (isl_seq_first_non_zero(info.val + n_out, n_div) >= 0)
+ continue;
+ hash = isl_seq_get_hash(info.val, info.n_out);
+ entry = isl_hash_table_find(ctx, table, hash,
+ constraint_equal, &info, 1);
+ if (!entry)
+ goto error;
+ if (entry->data)
+ break;
+ entry->data = &bmap->ineq[i];
+ }
+
+ if (i < bmap->n_ineq) {
+ *first = ((isl_int **)entry->data) - bmap->ineq;
+ *second = i;
+ }
+
+ isl_hash_table_free(ctx, table);
+
+ return i < bmap->n_ineq;
+error:
+ isl_hash_table_free(ctx, table);
+ return -1;
+}
+
+/* Given a set of upper bounds on the last "input" variable m,
+ * construct a set that assigns the minimal upper bound to m, i.e.,
+ * construct a set that divides the space into cells where one
+ * of the upper bounds is smaller than all the others and assign
+ * this upper bound to m.
+ *
+ * In particular, if there are n bounds b_i, then the result
+ * consists of n basic sets, each one of the form
+ *
+ * m = b_i
+ * b_i <= b_j for j > i
+ * b_i < b_j for j < i
+ */
+static __isl_give isl_set *set_minimum(__isl_take isl_dim *dim,
+ __isl_take isl_mat *var)
+{
+ int i, j, k;
+ isl_basic_set *bset = NULL;
+ isl_ctx *ctx;
+ isl_set *set = NULL;
+
+ if (!dim || !var)
+ goto error;
+
+ ctx = isl_dim_get_ctx(dim);
+ set = isl_set_alloc_dim(isl_dim_copy(dim),
+ var->n_row, ISL_SET_DISJOINT);
+
+ for (i = 0; i < var->n_row; ++i) {
+ bset = isl_basic_set_alloc_dim(isl_dim_copy(dim), 0,
+ 1, var->n_row - 1);
+ k = isl_basic_set_alloc_equality(bset);
+ if (k < 0)
+ goto error;
+ isl_seq_cpy(bset->eq[k], var->row[i], var->n_col);
+ isl_int_set_si(bset->eq[k][var->n_col], -1);
+ for (j = 0; j < var->n_row; ++j) {
+ if (j == i)
+ continue;
+ k = isl_basic_set_alloc_inequality(bset);
+ if (k < 0)
+ goto error;
+ isl_seq_combine(bset->ineq[k], ctx->one, var->row[j],
+ ctx->negone, var->row[i],
+ var->n_col);
+ isl_int_set_si(bset->ineq[k][var->n_col], 0);
+ if (j < i)
+ isl_int_sub_ui(bset->ineq[k][0],
+ bset->ineq[k][0], 1);
+ }
+ bset = isl_basic_set_finalize(bset);
+ set = isl_set_add_basic_set(set, bset);
+ }
+
+ isl_dim_free(dim);
+ isl_mat_free(var);
+ return set;
+error:
+ isl_basic_set_free(bset);
+ isl_set_free(set);
+ isl_dim_free(dim);
+ isl_mat_free(var);
+ return NULL;
+}
+
+/* Given that the last input variable of "bmap" represents the minimum
+ * of the bounds in "cst", check whether we need to split the domain
+ * based on which bound attains the minimum.
+ *
+ * A split is needed when the minimum appears in an integer division
+ * or in an equality. Otherwise, it is only needed if it appears in
+ * an upper bound that is different from the upper bounds on which it
+ * is defined.
+ */
+static int need_split_map(__isl_keep isl_basic_map *bmap,
+ __isl_keep isl_mat *cst)
+{
+ int i, j;
+ unsigned total;
+ unsigned pos;
+
+ pos = cst->n_col - 1;
+ total = isl_basic_map_dim(bmap, isl_dim_all);
+
+ for (i = 0; i < bmap->n_div; ++i)
+ if (!isl_int_is_zero(bmap->div[i][2 + pos]))
+ return 1;
+
+ for (i = 0; i < bmap->n_eq; ++i)
+ if (!isl_int_is_zero(bmap->eq[i][1 + pos]))
+ return 1;
+
+ for (i = 0; i < bmap->n_ineq; ++i) {
+ if (isl_int_is_nonneg(bmap->ineq[i][1 + pos]))
+ continue;
+ if (!isl_int_is_negone(bmap->ineq[i][1 + pos]))
+ return 1;
+ if (isl_seq_first_non_zero(bmap->ineq[i] + 1 + pos + 1,
+ total - pos - 1) >= 0)
+ return 1;
+
+ for (j = 0; j < cst->n_row; ++j)
+ if (isl_seq_eq(bmap->ineq[i], cst->row[j], cst->n_col))
+ break;
+ if (j >= cst->n_row)
+ return 1;
+ }
+
+ return 0;
+}
+
+static int need_split_set(__isl_keep isl_basic_set *bset,
+ __isl_keep isl_mat *cst)
+{
+ return need_split_map((isl_basic_map *)bset, cst);
+}
+
+/* Given a set of which the last set variable is the minimum
+ * of the bounds in "cst", split each basic set in the set
+ * in pieces where one of the bounds is (strictly) smaller than the others.
+ * This subdivision is given in "min_expr".
+ * The variable is subsequently projected out.
+ *
+ * We only do the split when it is needed.
+ * For example if the last input variable m = min(a,b) and the only
+ * constraints in the given basic set are lower bounds on m,
+ * i.e., l <= m = min(a,b), then we can simply project out m
+ * to obtain l <= a and l <= b, without having to split on whether
+ * m is equal to a or b.
+ */
+static __isl_give isl_set *split(__isl_take isl_set *empty,
+ __isl_take isl_set *min_expr, __isl_take isl_mat *cst)
+{
+ int n_in;
+ int i;
+ isl_dim *dim;
+ isl_set *res;
+
+ if (!empty || !min_expr || !cst)
+ goto error;
+
+ n_in = isl_set_dim(empty, isl_dim_set);
+ dim = isl_set_get_dim(empty);
+ dim = isl_dim_drop(dim, isl_dim_set, n_in - 1, 1);
+ res = isl_set_empty(dim);
+
+ for (i = 0; i < empty->n; ++i) {
+ isl_set *set;
+
+ set = isl_set_from_basic_set(isl_basic_set_copy(empty->p[i]));
+ if (need_split_set(empty->p[i], cst))
+ set = isl_set_intersect(set, isl_set_copy(min_expr));
+ set = isl_set_remove_dims(set, isl_dim_set, n_in - 1, 1);
+
+ res = isl_set_union_disjoint(res, set);
+ }
+
+ isl_set_free(empty);
+ isl_set_free(min_expr);
+ isl_mat_free(cst);
+ return res;
+error:
+ isl_set_free(empty);
+ isl_set_free(min_expr);
+ isl_mat_free(cst);
+ return NULL;
+}
+
+/* Given a map of which the last input variable is the minimum
+ * of the bounds in "cst", split each basic set in the set
+ * in pieces where one of the bounds is (strictly) smaller than the others.
+ * This subdivision is given in "min_expr".
+ * The variable is subsequently projected out.
+ *
+ * The implementation is essentially the same as that of "split".
+ */
+static __isl_give isl_map *split_domain(__isl_take isl_map *opt,
+ __isl_take isl_set *min_expr, __isl_take isl_mat *cst)
+{
+ int n_in;
+ int i;
+ isl_dim *dim;
+ isl_map *res;
+
+ if (!opt || !min_expr || !cst)
+ goto error;
+
+ n_in = isl_map_dim(opt, isl_dim_in);
+ dim = isl_map_get_dim(opt);
+ dim = isl_dim_drop(dim, isl_dim_in, n_in - 1, 1);
+ res = isl_map_empty(dim);
+
+ for (i = 0; i < opt->n; ++i) {
+ isl_map *map;
+
+ map = isl_map_from_basic_map(isl_basic_map_copy(opt->p[i]));
+ if (need_split_map(opt->p[i], cst))
+ map = isl_map_intersect_domain(map,
+ isl_set_copy(min_expr));
+ map = isl_map_remove_dims(map, isl_dim_in, n_in - 1, 1);
+
+ res = isl_map_union_disjoint(res, map);
+ }
+
+ isl_map_free(opt);
+ isl_set_free(min_expr);
+ isl_mat_free(cst);
+ return res;
+error:
+ isl_map_free(opt);
+ isl_set_free(min_expr);
+ isl_mat_free(cst);
+ return NULL;
+}
+
+static __isl_give isl_map *basic_map_partial_lexopt(
+ __isl_take isl_basic_map *bmap, __isl_take isl_basic_set *dom,
+ __isl_give isl_set **empty, int max);
+
+/* Given a basic map with at least two parallel constraints (as found
+ * by the function parallel_constraints), first look for more constraints
+ * parallel to the two constraint and replace the found list of parallel
+ * constraints by a single constraint with as "input" part the minimum
+ * of the input parts of the list of constraints. Then, recursively call
+ * basic_map_partial_lexopt (possibly finding more parallel constraints)
+ * and plug in the definition of the minimum in the result.
+ *
+ * More specifically, given a set of constraints
+ *
+ * a x + b_i(p) >= 0
+ *
+ * Replace this set by a single constraint
+ *
+ * a x + u >= 0
+ *
+ * with u a new parameter with constraints
+ *
+ * u <= b_i(p)
+ *
+ * Any solution to the new system is also a solution for the original system
+ * since
+ *
+ * a x >= -u >= -b_i(p)
+ *
+ * Moreover, m = min_i(b_i(p)) satisfies the constraints on u and can
+ * therefore be plugged into the solution.
+ */
+static __isl_give isl_map *basic_map_partial_lexopt_symm(
+ __isl_take isl_basic_map *bmap, __isl_take isl_basic_set *dom,
+ __isl_give isl_set **empty, int max, int first, int second)
+{
+ int i, n, k;
+ int *list = NULL;
+ unsigned n_in, n_out, n_div;
+ isl_ctx *ctx;
+ isl_vec *var = NULL;
+ isl_mat *cst = NULL;
+ isl_map *opt;
+ isl_set *min_expr;
+ isl_dim *map_dim, *set_dim;
+
+ map_dim = isl_basic_map_get_dim(bmap);
+ set_dim = empty ? isl_basic_set_get_dim(dom) : NULL;
+
+ n_in = isl_basic_map_dim(bmap, isl_dim_param) +
+ isl_basic_map_dim(bmap, isl_dim_in);
+ n_out = isl_basic_map_dim(bmap, isl_dim_all) - n_in;
+
+ ctx = isl_basic_map_get_ctx(bmap);
+ list = isl_alloc_array(ctx, int, bmap->n_ineq);
+ var = isl_vec_alloc(ctx, n_out);
+ if (!list || !var)
+ goto error;
+
+ list[0] = first;
+ list[1] = second;
+ isl_seq_cpy(var->el, bmap->ineq[first] + 1 + n_in, n_out);
+ for (i = second + 1, n = 2; i < bmap->n_ineq; ++i) {
+ if (isl_seq_eq(var->el, bmap->ineq[i] + 1 + n_in, n_out))
+ list[n++] = i;
+ }
+
+ cst = isl_mat_alloc(ctx, n, 1 + n_in);
+ if (!cst)
+ goto error;
+
+ for (i = 0; i < n; ++i)
+ isl_seq_cpy(cst->row[i], bmap->ineq[list[i]], 1 + n_in);
+
+ bmap = isl_basic_map_cow(bmap);
+ if (!bmap)
+ goto error;
+ for (i = n - 1; i >= 0; --i)
+ if (isl_basic_map_drop_inequality(bmap, list[i]) < 0)
+ goto error;
+
+ bmap = isl_basic_map_add(bmap, isl_dim_in, 1);
+ bmap = isl_basic_map_extend_constraints(bmap, 0, 1);
+ k = isl_basic_map_alloc_inequality(bmap);
+ if (k < 0)
+ goto error;
+ isl_seq_clr(bmap->ineq[k], 1 + n_in);
+ isl_int_set_si(bmap->ineq[k][1 + n_in], 1);
+ isl_seq_cpy(bmap->ineq[k] + 1 + n_in + 1, var->el, n_out);
+ bmap = isl_basic_map_finalize(bmap);
+
+ n_div = isl_basic_set_dim(dom, isl_dim_div);
+ dom = isl_basic_set_add(dom, isl_dim_set, 1);
+ dom = isl_basic_set_extend_constraints(dom, 0, n);
+ for (i = 0; i < n; ++i) {
+ k = isl_basic_set_alloc_inequality(dom);
+ if (k < 0)
+ goto error;
+ isl_seq_cpy(dom->ineq[k], cst->row[i], 1 + n_in);
+ isl_int_set_si(dom->ineq[k][1 + n_in], -1);
+ isl_seq_clr(dom->ineq[k] + 1 + n_in + 1, n_div);
+ }
+
+ min_expr = set_minimum(isl_basic_set_get_dim(dom), isl_mat_copy(cst));
+
+ isl_vec_free(var);
+ free(list);
+
+ opt = basic_map_partial_lexopt(bmap, dom, empty, max);
+
+ if (empty) {
+ *empty = split(*empty,
+ isl_set_copy(min_expr), isl_mat_copy(cst));
+ *empty = isl_set_reset_dim(*empty, set_dim);
+ }
+
+ opt = split_domain(opt, min_expr, cst);
+ opt = isl_map_reset_dim(opt, map_dim);
+
+ return opt;
+error:
+ isl_dim_free(map_dim);
+ isl_dim_free(set_dim);
+ isl_mat_free(cst);
+ isl_vec_free(var);
+ free(list);
+ isl_basic_set_free(dom);
+ isl_basic_map_free(bmap);
+ return NULL;
+}
+
+/* Recursive part of isl_tab_basic_map_partial_lexopt, after detecting
+ * equalities and removing redundant constraints.
+ *
+ * We first check if there are any parallel constraints (left).
+ * If not, we are in the base case.
+ * If there are parallel constraints, we replace them by a single
+ * constraint in basic_map_partial_lexopt_symm and then call
+ * this function recursively to look for more parallel constraints.
+ */
+static __isl_give isl_map *basic_map_partial_lexopt(
+ __isl_take isl_basic_map *bmap, __isl_take isl_basic_set *dom,
+ __isl_give isl_set **empty, int max)
+{
+ int par = 0;
+ int first, second;
+
+ if (!bmap)
+ goto error;
+
+ if (bmap->ctx->opt->pip_symmetry)
+ par = parallel_constraints(bmap, &first, &second);
+ if (par < 0)
+ goto error;
+ if (!par)
+ return basic_map_partial_lexopt_base(bmap, dom, empty, max);
+
+ return basic_map_partial_lexopt_symm(bmap, dom, empty, max,
+ first, second);
+error:
+ isl_basic_set_free(dom);
+ isl_basic_map_free(bmap);
+ return NULL;
+}
+
+/* Compute the lexicographic minimum (or maximum if "max" is set)
+ * of "bmap" over the domain "dom" and return the result as a map.
+ * If "empty" is not NULL, then *empty is assigned a set that
+ * contains those parts of the domain where there is no solution.
+ * If "bmap" is marked as rational (ISL_BASIC_MAP_RATIONAL),
+ * then we compute the rational optimum. Otherwise, we compute
+ * the integral optimum.
+ *
+ * We perform some preprocessing. As the PILP solver does not
+ * handle implicit equalities very well, we first make sure all
+ * the equalities are explicitly available.
+ *
+ * We also add context constraints to the basic map and remove
+ * redundant constraints. This is only needed because of the
+ * way we handle simple symmetries. In particular, we currently look
+ * for symmetries on the constraints, before we set up the main tableau.
+ * It is then no good to look for symmetries on possibly redundant constraints.
+ */
+struct isl_map *isl_tab_basic_map_partial_lexopt(
+ struct isl_basic_map *bmap, struct isl_basic_set *dom,
+ struct isl_set **empty, int max)
+{
+ if (empty)
+ *empty = NULL;
+ if (!bmap || !dom)
+ goto error;
+
+ isl_assert(bmap->ctx,
+ isl_basic_map_compatible_domain(bmap, dom), goto error);
+
+ if (isl_basic_set_dim(dom, isl_dim_all) == 0)
+ return basic_map_partial_lexopt(bmap, dom, empty, max);
+
+ bmap = isl_basic_map_intersect_domain(bmap, isl_basic_set_copy(dom));
+ bmap = isl_basic_map_detect_equalities(bmap);
+ bmap = isl_basic_map_remove_redundancies(bmap);
+
+ return basic_map_partial_lexopt(bmap, dom, empty, max);
+error:
+ isl_basic_set_free(dom);
+ isl_basic_map_free(bmap);
+ return NULL;
+}
+
struct isl_sol_for {
struct isl_sol sol;
int (*fn)(__isl_take isl_basic_set *dom,
*
* Instead of constructing a basic map, this function calls a user
* defined function with the current context as a basic set and
- * an affine matrix reprenting the relation between the input and output.
+ * an affine matrix representing the relation between the input and output.
* The number of rows in this matrix is equal to one plus the number
* of output variables. The number of columns is equal to one plus
* the total dimension of the context, i.e., the number of parameters,
struct isl_dim *dom_dim;
struct isl_basic_set *dom = NULL;
- sol_for = isl_calloc_type(bset->ctx, struct isl_sol_for);
+ sol_for = isl_calloc_type(bmap->ctx, struct isl_sol_for);
if (!sol_for)
goto error;
projects / platform / upstream / isl.git / blobdiff