/*
* Copyright 2008-2009 Katholieke Universiteit Leuven
+ * Copyright 2013 Ecole Normale Superieure
*
- * Use of this software is governed by the GNU LGPLv2.1 license
+ * 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
+ * and Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France
*/
#include <isl_ctx_private.h>
#include "isl_map_private.h"
#include "isl_tab.h"
#include <isl/seq.h>
+#include <isl_config.h>
/*
* The implementation of tableaus in this file was inspired by Section 8
{
struct isl_tab_undo *undo;
+ if (!tab)
+ return -1;
if (!tab->need_undo)
return 0;
struct isl_tab_var *var = isl_tab_var_from_row(tab, row);
var->is_redundant = 1;
isl_assert(tab->mat->ctx, row >= tab->n_redundant, return -1);
- if (tab->need_undo || tab->row_var[row] >= 0) {
+ if (tab->preserve || tab->need_undo || tab->row_var[row] >= 0) {
if (tab->row_var[row] >= 0 && !var->is_nonneg) {
var->is_nonneg = 1;
if (isl_tab_push_var(tab, isl_tab_undo_nonneg, var) < 0)
return isl_tab_pivot(tab, r, var->index);
}
+/* Check whether all variables that are marked as non-negative
+ * also have a non-negative sample value. This function is not
+ * called from the current code but is useful during debugging.
+ */
+static void check_table(struct isl_tab *tab) __attribute__ ((unused));
static void check_table(struct isl_tab *tab)
{
int i;
if (nonneg)
tab->var[r].is_nonneg = 1;
- tab->bmap = isl_basic_map_extend_dim(tab->bmap,
- isl_basic_map_get_dim(tab->bmap), 1, 0, 2);
+ tab->bmap = isl_basic_map_extend_space(tab->bmap,
+ isl_basic_map_get_space(tab->bmap), 1, 0, 2);
k = isl_basic_map_alloc_div(tab->bmap);
if (k < 0)
return -1;
return r;
}
-struct isl_tab *isl_tab_from_basic_map(struct isl_basic_map *bmap)
+/* If "track" is set, then we want to keep track of all constraints in tab
+ * in its bmap field. This field is initialized from a copy of "bmap",
+ * so we need to make sure that all constraints in "bmap" also appear
+ * in the constructed tab.
+ */
+__isl_give struct isl_tab *isl_tab_from_basic_map(
+ __isl_keep isl_basic_map *bmap, int track)
{
int i;
struct isl_tab *tab;
isl_basic_map_total_dim(bmap), 0);
if (!tab)
return NULL;
+ tab->preserve = track;
tab->rational = ISL_F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL);
if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY)) {
if (isl_tab_mark_empty(tab) < 0)
goto error;
- return tab;
+ goto done;
}
for (i = 0; i < bmap->n_eq; ++i) {
tab = add_eq(tab, bmap->eq[i]);
if (isl_tab_add_ineq(tab, bmap->ineq[i]) < 0)
goto error;
if (tab->empty)
- return tab;
+ goto done;
}
+done:
+ if (track && isl_tab_track_bmap(tab, isl_basic_map_copy(bmap)) < 0)
+ goto error;
return tab;
error:
isl_tab_free(tab);
return NULL;
}
-struct isl_tab *isl_tab_from_basic_set(struct isl_basic_set *bset)
+__isl_give struct isl_tab *isl_tab_from_basic_set(
+ __isl_keep isl_basic_set *bset, int track)
{
- return isl_tab_from_basic_map((struct isl_basic_map *)bset);
+ return isl_tab_from_basic_map(bset, track);
}
/* Construct a tableau corresponding to the recession cone of "bset".
var = &tab->con[con];
+ if (var->is_row && (var->index < 0 || var->index < tab->n_redundant))
+ isl_die(tab->mat->ctx, isl_error_invalid,
+ "cannot relax redundant constraint", goto error);
+ if (!var->is_row && (var->index < 0 || var->index < tab->n_dead))
+ isl_die(tab->mat->ctx, isl_error_invalid,
+ "cannot relax dead constraint", goto error);
+
if (!var->is_row && !max_is_manifestly_unbounded(tab, var))
if (to_row(tab, var, 1) < 0)
goto error;
return 0;
}
+/* Update the element of row_var or col_var that corresponds to
+ * constraint tab->con[i] to a move from position "old" to position "i".
+ */
+static int update_con_after_move(struct isl_tab *tab, int i, int old)
+{
+ int *p;
+ int index;
+
+ index = tab->con[i].index;
+ if (index == -1)
+ return 0;
+ p = tab->con[i].is_row ? tab->row_var : tab->col_var;
+ if (p[index] != ~old)
+ isl_die(tab->mat->ctx, isl_error_internal,
+ "broken internal state", return -1);
+ p[index] = ~i;
+
+ return 0;
+}
+
+/* Rotate the "n" constraints starting at "first" to the right,
+ * putting the last constraint in the position of the first constraint.
+ */
+static int rotate_constraints(struct isl_tab *tab, int first, int n)
+{
+ int i, last;
+ struct isl_tab_var var;
+
+ if (n <= 1)
+ return 0;
+
+ last = first + n - 1;
+ var = tab->con[last];
+ for (i = last; i > first; --i) {
+ tab->con[i] = tab->con[i - 1];
+ if (update_con_after_move(tab, i, i - 1) < 0)
+ return -1;
+ }
+ tab->con[first] = var;
+ if (update_con_after_move(tab, first, last) < 0)
+ return -1;
+
+ return 0;
+}
+
+/* Make the equalities that are implicit in "bmap" but that have been
+ * detected in the corresponding "tab" explicit in "bmap" and update
+ * "tab" to reflect the new order of the constraints.
+ *
+ * In particular, if inequality i is an implicit equality then
+ * isl_basic_map_inequality_to_equality will move the inequality
+ * in front of the other equality and it will move the last inequality
+ * in the position of inequality i.
+ * In the tableau, the inequalities of "bmap" are stored after the equalities
+ * and so the original order
+ *
+ * E E E E E A A A I B B B B L
+ *
+ * is changed into
+ *
+ * I E E E E E A A A L B B B B
+ *
+ * where I is the implicit equality, the E are equalities,
+ * the A inequalities before I, the B inequalities after I and
+ * L the last inequality.
+ * We therefore need to rotate to the right two sets of constraints,
+ * those up to and including I and those after I.
+ *
+ * If "tab" contains any constraints that are not in "bmap" then they
+ * appear after those in "bmap" and they should be left untouched.
+ *
+ * Note that this function leaves "bmap" in a temporary state
+ * as it does not call isl_basic_map_gauss. Calling this function
+ * is the responsibility of the caller.
+ */
+__isl_give isl_basic_map *isl_tab_make_equalities_explicit(struct isl_tab *tab,
+ __isl_take isl_basic_map *bmap)
+{
+ int i;
+
+ if (!tab || !bmap)
+ return isl_basic_map_free(bmap);
+ if (tab->empty)
+ return bmap;
+
+ for (i = bmap->n_ineq - 1; i >= 0; --i) {
+ if (!isl_tab_is_equality(tab, bmap->n_eq + i))
+ continue;
+ isl_basic_map_inequality_to_equality(bmap, i);
+ if (rotate_constraints(tab, 0, tab->n_eq + i + 1) < 0)
+ return isl_basic_map_free(bmap);
+ if (rotate_constraints(tab, tab->n_eq + i + 1,
+ bmap->n_ineq - i) < 0)
+ return isl_basic_map_free(bmap);
+ tab->n_eq++;
+ }
+
+ return bmap;
+}
+
static int con_is_redundant(struct isl_tab *tab, struct isl_tab_var *var)
{
if (!tab)
static int perform_undo_var(struct isl_tab *tab, struct isl_tab_undo *undo)
{
struct isl_tab_var *var = var_from_index(tab, undo->u.var_index);
- switch(undo->type) {
+ switch (undo->type) {
case isl_tab_undo_nonneg:
var->is_nonneg = 0;
break;
break;
case isl_tab_undo_relax:
return unrelax(tab, var);
+ default:
+ isl_die(tab->mat->ctx, isl_error_internal,
+ "perform_undo_var called on invalid undo record",
+ return -1);
}
return 0;
int isl_tab_track_bmap(struct isl_tab *tab, __isl_take isl_basic_map *bmap)
{
+ bmap = isl_basic_map_cow(bmap);
if (!tab || !bmap)
goto error;
- isl_assert(tab->mat->ctx, tab->n_eq == bmap->n_eq, return -1);
+ if (tab->empty) {
+ bmap = isl_basic_map_set_to_empty(bmap);
+ if (!bmap)
+ goto error;
+ tab->bmap = bmap;
+ return 0;
+ }
+
+ isl_assert(tab->mat->ctx, tab->n_eq == bmap->n_eq, goto error);
isl_assert(tab->mat->ctx,
- tab->n_con == bmap->n_eq + bmap->n_ineq, return -1);
+ tab->n_con == bmap->n_eq + bmap->n_ineq, goto error);
tab->bmap = bmap;
projects / platform / upstream / isl.git / blobdiff