-#include "isl_mat.h"
+/*
+ * Copyright 2008-2009 Katholieke Universiteit Leuven
+ * Copyright 2013 Ecole Normale Superieure
+ *
+ * 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_mat_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 *isl_tab_alloc(struct isl_ctx *ctx,
- unsigned n_row, unsigned n_var)
+ unsigned n_row, unsigned n_var, unsigned M)
{
int i;
struct isl_tab *tab;
+ unsigned off = 2 + M;
tab = isl_calloc_type(ctx, struct isl_tab);
if (!tab)
return NULL;
- tab->mat = isl_mat_alloc(ctx, n_row, 2 + n_var);
+ tab->mat = isl_mat_alloc(ctx, n_row, off + n_var);
if (!tab->mat)
goto error;
tab->var = isl_alloc_array(ctx, struct isl_tab_var, n_var);
tab->var[i].is_zero = 0;
tab->var[i].is_redundant = 0;
tab->var[i].frozen = 0;
+ tab->var[i].negated = 0;
tab->col_var[i] = i;
}
tab->n_row = 0;
tab->max_con = n_row;
tab->n_col = n_var;
tab->n_var = n_var;
+ tab->max_var = n_var;
+ tab->n_param = 0;
+ tab->n_div = 0;
tab->n_dead = 0;
tab->n_redundant = 0;
+ tab->strict_redundant = 0;
tab->need_undo = 0;
tab->rational = 0;
tab->empty = 0;
tab->in_undo = 0;
+ tab->M = M;
+ tab->cone = 0;
tab->bottom.type = isl_tab_undo_bottom;
tab->bottom.next = NULL;
tab->top = &tab->bottom;
+
+ tab->n_zero = 0;
+ tab->n_unbounded = 0;
+ tab->basis = NULL;
+
return tab;
error:
isl_tab_free(tab);
return NULL;
}
-static int extend_cons(struct isl_tab *tab, unsigned n_new)
+isl_ctx *isl_tab_get_ctx(struct isl_tab *tab)
+{
+ return tab ? isl_mat_get_ctx(tab->mat) : NULL;
+}
+
+int isl_tab_extend_cons(struct isl_tab *tab, unsigned n_new)
{
+ unsigned off;
+
+ if (!tab)
+ return -1;
+
+ off = 2 + tab->M;
+
if (tab->max_con < tab->n_con + n_new) {
struct isl_tab_var *con;
int *row_var;
tab->mat = isl_mat_extend(tab->mat,
- tab->n_row + n_new, tab->n_col);
+ tab->n_row + n_new, off + tab->n_col);
if (!tab->mat)
return -1;
row_var = isl_realloc_array(tab->mat->ctx, tab->row_var,
if (!row_var)
return -1;
tab->row_var = row_var;
+ if (tab->row_sign) {
+ enum isl_tab_row_sign *s;
+ s = isl_realloc_array(tab->mat->ctx, tab->row_sign,
+ enum isl_tab_row_sign, tab->mat->n_row);
+ if (!s)
+ return -1;
+ tab->row_sign = s;
+ }
+ }
+ return 0;
+}
+
+/* Make room for at least n_new extra variables.
+ * Return -1 if anything went wrong.
+ */
+int isl_tab_extend_vars(struct isl_tab *tab, unsigned n_new)
+{
+ struct isl_tab_var *var;
+ unsigned off = 2 + tab->M;
+
+ if (tab->max_var < tab->n_var + n_new) {
+ var = isl_realloc_array(tab->mat->ctx, tab->var,
+ struct isl_tab_var, tab->n_var + n_new);
+ if (!var)
+ return -1;
+ tab->var = var;
+ tab->max_var += n_new;
+ }
+
+ if (tab->mat->n_col < off + tab->n_col + n_new) {
+ int *p;
+
+ tab->mat = isl_mat_extend(tab->mat,
+ tab->mat->n_row, off + tab->n_col + n_new);
+ if (!tab->mat)
+ return -1;
+ p = isl_realloc_array(tab->mat->ctx, tab->col_var,
+ int, tab->n_col + n_new);
+ if (!p)
+ return -1;
+ tab->col_var = p;
}
+
return 0;
}
struct isl_tab *isl_tab_extend(struct isl_tab *tab, unsigned n_new)
{
- if (extend_cons(tab, n_new) >= 0)
+ if (isl_tab_extend_cons(tab, n_new) >= 0)
return tab;
isl_tab_free(tab);
return NULL;
}
+static void free_undo_record(struct isl_tab_undo *undo)
+{
+ switch (undo->type) {
+ case isl_tab_undo_saved_basis:
+ free(undo->u.col_var);
+ break;
+ default:;
+ }
+ free(undo);
+}
+
static void free_undo(struct isl_tab *tab)
{
struct isl_tab_undo *undo, *next;
for (undo = tab->top; undo && undo != &tab->bottom; undo = next) {
next = undo->next;
- free(undo);
+ free_undo_record(undo);
}
tab->top = undo;
}
free_undo(tab);
isl_mat_free(tab->mat);
isl_vec_free(tab->dual);
+ isl_basic_map_free(tab->bmap);
free(tab->var);
free(tab->con);
free(tab->row_var);
free(tab->col_var);
+ free(tab->row_sign);
+ isl_mat_free(tab->samples);
+ free(tab->sample_index);
+ isl_mat_free(tab->basis);
free(tab);
}
{
int i;
struct isl_tab *dup;
+ unsigned off;
if (!tab)
return NULL;
- dup = isl_calloc_type(tab->ctx, struct isl_tab);
+ off = 2 + tab->M;
+ dup = isl_calloc_type(tab->mat->ctx, struct isl_tab);
if (!dup)
return NULL;
dup->mat = isl_mat_dup(tab->mat);
if (!dup->mat)
goto error;
- dup->var = isl_alloc_array(tab->ctx, struct isl_tab_var, tab->n_var);
+ dup->var = isl_alloc_array(tab->mat->ctx, struct isl_tab_var, tab->max_var);
if (!dup->var)
goto error;
for (i = 0; i < tab->n_var; ++i)
dup->var[i] = tab->var[i];
- dup->con = isl_alloc_array(tab->ctx, struct isl_tab_var, tab->max_con);
+ dup->con = isl_alloc_array(tab->mat->ctx, struct isl_tab_var, tab->max_con);
if (!dup->con)
goto error;
for (i = 0; i < tab->n_con; ++i)
dup->con[i] = tab->con[i];
- dup->col_var = isl_alloc_array(tab->ctx, int, tab->mat->n_col);
+ dup->col_var = isl_alloc_array(tab->mat->ctx, int, tab->mat->n_col - off);
if (!dup->col_var)
goto error;
- for (i = 0; i < tab->n_var; ++i)
+ for (i = 0; i < tab->n_col; ++i)
dup->col_var[i] = tab->col_var[i];
- dup->row_var = isl_alloc_array(tab->ctx, int, tab->mat->n_row);
+ dup->row_var = isl_alloc_array(tab->mat->ctx, int, tab->mat->n_row);
if (!dup->row_var)
goto error;
for (i = 0; i < tab->n_row; ++i)
dup->row_var[i] = tab->row_var[i];
+ if (tab->row_sign) {
+ dup->row_sign = isl_alloc_array(tab->mat->ctx, enum isl_tab_row_sign,
+ tab->mat->n_row);
+ if (!dup->row_sign)
+ goto error;
+ for (i = 0; i < tab->n_row; ++i)
+ dup->row_sign[i] = tab->row_sign[i];
+ }
+ if (tab->samples) {
+ dup->samples = isl_mat_dup(tab->samples);
+ if (!dup->samples)
+ goto error;
+ dup->sample_index = isl_alloc_array(tab->mat->ctx, int,
+ tab->samples->n_row);
+ if (!dup->sample_index)
+ goto error;
+ dup->n_sample = tab->n_sample;
+ dup->n_outside = tab->n_outside;
+ }
dup->n_row = tab->n_row;
dup->n_con = tab->n_con;
dup->n_eq = tab->n_eq;
dup->max_con = tab->max_con;
dup->n_col = tab->n_col;
dup->n_var = tab->n_var;
+ dup->max_var = tab->max_var;
+ dup->n_param = tab->n_param;
+ dup->n_div = tab->n_div;
dup->n_dead = tab->n_dead;
dup->n_redundant = tab->n_redundant;
dup->rational = tab->rational;
dup->empty = tab->empty;
+ dup->strict_redundant = 0;
dup->need_undo = 0;
dup->in_undo = 0;
+ dup->M = tab->M;
+ tab->cone = tab->cone;
dup->bottom.type = isl_tab_undo_bottom;
dup->bottom.next = NULL;
dup->top = &dup->bottom;
+
+ dup->n_zero = tab->n_zero;
+ dup->n_unbounded = tab->n_unbounded;
+ dup->basis = isl_mat_dup(tab->basis);
+
return dup;
error:
isl_tab_free(dup);
return NULL;
}
+/* Construct the coefficient matrix of the product tableau
+ * of two tableaus.
+ * mat{1,2} is the coefficient matrix of tableau {1,2}
+ * row{1,2} is the number of rows in tableau {1,2}
+ * col{1,2} is the number of columns in tableau {1,2}
+ * off is the offset to the coefficient column (skipping the
+ * denominator, the constant term and the big parameter if any)
+ * r{1,2} is the number of redundant rows in tableau {1,2}
+ * d{1,2} is the number of dead columns in tableau {1,2}
+ *
+ * The order of the rows and columns in the result is as explained
+ * in isl_tab_product.
+ */
+static struct isl_mat *tab_mat_product(struct isl_mat *mat1,
+ struct isl_mat *mat2, unsigned row1, unsigned row2,
+ unsigned col1, unsigned col2,
+ unsigned off, unsigned r1, unsigned r2, unsigned d1, unsigned d2)
+{
+ int i;
+ struct isl_mat *prod;
+ unsigned n;
+
+ prod = isl_mat_alloc(mat1->ctx, mat1->n_row + mat2->n_row,
+ off + col1 + col2);
+ if (!prod)
+ return NULL;
+
+ n = 0;
+ for (i = 0; i < r1; ++i) {
+ isl_seq_cpy(prod->row[n + i], mat1->row[i], off + d1);
+ isl_seq_clr(prod->row[n + i] + off + d1, d2);
+ isl_seq_cpy(prod->row[n + i] + off + d1 + d2,
+ mat1->row[i] + off + d1, col1 - d1);
+ isl_seq_clr(prod->row[n + i] + off + col1 + d1, col2 - d2);
+ }
+
+ n += r1;
+ for (i = 0; i < r2; ++i) {
+ isl_seq_cpy(prod->row[n + i], mat2->row[i], off);
+ isl_seq_clr(prod->row[n + i] + off, d1);
+ isl_seq_cpy(prod->row[n + i] + off + d1,
+ mat2->row[i] + off, d2);
+ isl_seq_clr(prod->row[n + i] + off + d1 + d2, col1 - d1);
+ isl_seq_cpy(prod->row[n + i] + off + col1 + d1,
+ mat2->row[i] + off + d2, col2 - d2);
+ }
+
+ n += r2;
+ for (i = 0; i < row1 - r1; ++i) {
+ isl_seq_cpy(prod->row[n + i], mat1->row[r1 + i], off + d1);
+ isl_seq_clr(prod->row[n + i] + off + d1, d2);
+ isl_seq_cpy(prod->row[n + i] + off + d1 + d2,
+ mat1->row[r1 + i] + off + d1, col1 - d1);
+ isl_seq_clr(prod->row[n + i] + off + col1 + d1, col2 - d2);
+ }
+
+ n += row1 - r1;
+ for (i = 0; i < row2 - r2; ++i) {
+ isl_seq_cpy(prod->row[n + i], mat2->row[r2 + i], off);
+ isl_seq_clr(prod->row[n + i] + off, d1);
+ isl_seq_cpy(prod->row[n + i] + off + d1,
+ mat2->row[r2 + i] + off, d2);
+ isl_seq_clr(prod->row[n + i] + off + d1 + d2, col1 - d1);
+ isl_seq_cpy(prod->row[n + i] + off + col1 + d1,
+ mat2->row[r2 + i] + off + d2, col2 - d2);
+ }
+
+ return prod;
+}
+
+/* Update the row or column index of a variable that corresponds
+ * to a variable in the first input tableau.
+ */
+static void update_index1(struct isl_tab_var *var,
+ unsigned r1, unsigned r2, unsigned d1, unsigned d2)
+{
+ if (var->index == -1)
+ return;
+ if (var->is_row && var->index >= r1)
+ var->index += r2;
+ if (!var->is_row && var->index >= d1)
+ var->index += d2;
+}
+
+/* Update the row or column index of a variable that corresponds
+ * to a variable in the second input tableau.
+ */
+static void update_index2(struct isl_tab_var *var,
+ unsigned row1, unsigned col1,
+ unsigned r1, unsigned r2, unsigned d1, unsigned d2)
+{
+ if (var->index == -1)
+ return;
+ if (var->is_row) {
+ if (var->index < r2)
+ var->index += r1;
+ else
+ var->index += row1;
+ } else {
+ if (var->index < d2)
+ var->index += d1;
+ else
+ var->index += col1;
+ }
+}
+
+/* Create a tableau that represents the Cartesian product of the sets
+ * represented by tableaus tab1 and tab2.
+ * The order of the rows in the product is
+ * - redundant rows of tab1
+ * - redundant rows of tab2
+ * - non-redundant rows of tab1
+ * - non-redundant rows of tab2
+ * The order of the columns is
+ * - denominator
+ * - constant term
+ * - coefficient of big parameter, if any
+ * - dead columns of tab1
+ * - dead columns of tab2
+ * - live columns of tab1
+ * - live columns of tab2
+ * The order of the variables and the constraints is a concatenation
+ * of order in the two input tableaus.
+ */
+struct isl_tab *isl_tab_product(struct isl_tab *tab1, struct isl_tab *tab2)
+{
+ int i;
+ struct isl_tab *prod;
+ unsigned off;
+ unsigned r1, r2, d1, d2;
+
+ if (!tab1 || !tab2)
+ return NULL;
+
+ isl_assert(tab1->mat->ctx, tab1->M == tab2->M, return NULL);
+ isl_assert(tab1->mat->ctx, tab1->rational == tab2->rational, return NULL);
+ isl_assert(tab1->mat->ctx, tab1->cone == tab2->cone, return NULL);
+ isl_assert(tab1->mat->ctx, !tab1->row_sign, return NULL);
+ isl_assert(tab1->mat->ctx, !tab2->row_sign, return NULL);
+ isl_assert(tab1->mat->ctx, tab1->n_param == 0, return NULL);
+ isl_assert(tab1->mat->ctx, tab2->n_param == 0, return NULL);
+ isl_assert(tab1->mat->ctx, tab1->n_div == 0, return NULL);
+ isl_assert(tab1->mat->ctx, tab2->n_div == 0, return NULL);
+
+ off = 2 + tab1->M;
+ r1 = tab1->n_redundant;
+ r2 = tab2->n_redundant;
+ d1 = tab1->n_dead;
+ d2 = tab2->n_dead;
+ prod = isl_calloc_type(tab1->mat->ctx, struct isl_tab);
+ if (!prod)
+ return NULL;
+ prod->mat = tab_mat_product(tab1->mat, tab2->mat,
+ tab1->n_row, tab2->n_row,
+ tab1->n_col, tab2->n_col, off, r1, r2, d1, d2);
+ if (!prod->mat)
+ goto error;
+ prod->var = isl_alloc_array(tab1->mat->ctx, struct isl_tab_var,
+ tab1->max_var + tab2->max_var);
+ if (!prod->var)
+ goto error;
+ for (i = 0; i < tab1->n_var; ++i) {
+ prod->var[i] = tab1->var[i];
+ update_index1(&prod->var[i], r1, r2, d1, d2);
+ }
+ for (i = 0; i < tab2->n_var; ++i) {
+ prod->var[tab1->n_var + i] = tab2->var[i];
+ update_index2(&prod->var[tab1->n_var + i],
+ tab1->n_row, tab1->n_col,
+ r1, r2, d1, d2);
+ }
+ prod->con = isl_alloc_array(tab1->mat->ctx, struct isl_tab_var,
+ tab1->max_con + tab2->max_con);
+ if (!prod->con)
+ goto error;
+ for (i = 0; i < tab1->n_con; ++i) {
+ prod->con[i] = tab1->con[i];
+ update_index1(&prod->con[i], r1, r2, d1, d2);
+ }
+ for (i = 0; i < tab2->n_con; ++i) {
+ prod->con[tab1->n_con + i] = tab2->con[i];
+ update_index2(&prod->con[tab1->n_con + i],
+ tab1->n_row, tab1->n_col,
+ r1, r2, d1, d2);
+ }
+ prod->col_var = isl_alloc_array(tab1->mat->ctx, int,
+ tab1->n_col + tab2->n_col);
+ if (!prod->col_var)
+ goto error;
+ for (i = 0; i < tab1->n_col; ++i) {
+ int pos = i < d1 ? i : i + d2;
+ prod->col_var[pos] = tab1->col_var[i];
+ }
+ for (i = 0; i < tab2->n_col; ++i) {
+ int pos = i < d2 ? d1 + i : tab1->n_col + i;
+ int t = tab2->col_var[i];
+ if (t >= 0)
+ t += tab1->n_var;
+ else
+ t -= tab1->n_con;
+ prod->col_var[pos] = t;
+ }
+ prod->row_var = isl_alloc_array(tab1->mat->ctx, int,
+ tab1->mat->n_row + tab2->mat->n_row);
+ if (!prod->row_var)
+ goto error;
+ for (i = 0; i < tab1->n_row; ++i) {
+ int pos = i < r1 ? i : i + r2;
+ prod->row_var[pos] = tab1->row_var[i];
+ }
+ for (i = 0; i < tab2->n_row; ++i) {
+ int pos = i < r2 ? r1 + i : tab1->n_row + i;
+ int t = tab2->row_var[i];
+ if (t >= 0)
+ t += tab1->n_var;
+ else
+ t -= tab1->n_con;
+ prod->row_var[pos] = t;
+ }
+ prod->samples = NULL;
+ prod->sample_index = NULL;
+ prod->n_row = tab1->n_row + tab2->n_row;
+ prod->n_con = tab1->n_con + tab2->n_con;
+ prod->n_eq = 0;
+ prod->max_con = tab1->max_con + tab2->max_con;
+ prod->n_col = tab1->n_col + tab2->n_col;
+ prod->n_var = tab1->n_var + tab2->n_var;
+ prod->max_var = tab1->max_var + tab2->max_var;
+ prod->n_param = 0;
+ prod->n_div = 0;
+ prod->n_dead = tab1->n_dead + tab2->n_dead;
+ prod->n_redundant = tab1->n_redundant + tab2->n_redundant;
+ prod->rational = tab1->rational;
+ prod->empty = tab1->empty || tab2->empty;
+ prod->strict_redundant = tab1->strict_redundant || tab2->strict_redundant;
+ prod->need_undo = 0;
+ prod->in_undo = 0;
+ prod->M = tab1->M;
+ prod->cone = tab1->cone;
+ prod->bottom.type = isl_tab_undo_bottom;
+ prod->bottom.next = NULL;
+ prod->top = &prod->bottom;
+
+ prod->n_zero = 0;
+ prod->n_unbounded = 0;
+ prod->basis = NULL;
+
+ return prod;
+error:
+ isl_tab_free(prod);
+ return NULL;
+}
+
static struct isl_tab_var *var_from_index(struct isl_tab *tab, int i)
{
if (i >= 0)
return &tab->con[~i];
}
-static struct isl_tab_var *var_from_row(struct isl_tab *tab, int i)
+struct isl_tab_var *isl_tab_var_from_row(struct isl_tab *tab, int i)
{
return var_from_index(tab, tab->row_var[i]);
}
struct isl_tab_var *var)
{
int i;
+ unsigned off = 2 + tab->M;
if (var->is_row)
return 0;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- if (!isl_int_is_neg(tab->mat->row[i][2 + var->index]))
+ if (!isl_int_is_neg(tab->mat->row[i][off + var->index]))
continue;
- if (var_from_row(tab, i)->is_nonneg)
+ if (isl_tab_var_from_row(tab, i)->is_nonneg)
return 0;
}
return 1;
struct isl_tab_var *var)
{
int i;
+ unsigned off = 2 + tab->M;
if (var->is_row)
return 0;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- if (!isl_int_is_pos(tab->mat->row[i][2 + var->index]))
+ if (!isl_int_is_pos(tab->mat->row[i][off + var->index]))
continue;
- if (var_from_row(tab, i)->is_nonneg)
+ if (isl_tab_var_from_row(tab, i)->is_nonneg)
return 0;
}
return 1;
}
+static int row_cmp(struct isl_tab *tab, int r1, int r2, int c, isl_int t)
+{
+ unsigned off = 2 + tab->M;
+
+ if (tab->M) {
+ int s;
+ isl_int_mul(t, tab->mat->row[r1][2], tab->mat->row[r2][off+c]);
+ isl_int_submul(t, tab->mat->row[r2][2], tab->mat->row[r1][off+c]);
+ s = isl_int_sgn(t);
+ if (s)
+ return s;
+ }
+ isl_int_mul(t, tab->mat->row[r1][1], tab->mat->row[r2][off + c]);
+ isl_int_submul(t, tab->mat->row[r2][1], tab->mat->row[r1][off + c]);
+ return isl_int_sgn(t);
+}
+
/* Given the index of a column "c", return the index of a row
* that can be used to pivot the column in, with either an increase
* (sgn > 0) or a decrease (sgn < 0) of the corresponding variable.
{
int j, r, tsgn;
isl_int t;
+ unsigned off = 2 + tab->M;
isl_int_init(t);
r = -1;
for (j = tab->n_redundant; j < tab->n_row; ++j) {
if (var && j == var->index)
continue;
- if (!var_from_row(tab, j)->is_nonneg)
+ if (!isl_tab_var_from_row(tab, j)->is_nonneg)
continue;
- if (sgn * isl_int_sgn(tab->mat->row[j][2 + c]) >= 0)
+ if (sgn * isl_int_sgn(tab->mat->row[j][off + c]) >= 0)
continue;
if (r < 0) {
r = j;
continue;
}
- isl_int_mul(t, tab->mat->row[r][1], tab->mat->row[j][2 + c]);
- isl_int_submul(t, tab->mat->row[j][1], tab->mat->row[r][2 + c]);
- tsgn = sgn * isl_int_sgn(t);
+ tsgn = sgn * row_cmp(tab, r, j, c, t);
if (tsgn < 0 || (tsgn == 0 &&
tab->row_var[j] < tab->row_var[r]))
r = j;
*row = *col = -1;
isl_assert(tab->mat->ctx, var->is_row, return);
- tr = tab->mat->row[var->index];
+ tr = tab->mat->row[var->index] + 2 + tab->M;
c = -1;
for (j = tab->n_dead; j < tab->n_col; ++j) {
- if (isl_int_is_zero(tr[2 + j]))
+ if (isl_int_is_zero(tr[j]))
continue;
- if (isl_int_sgn(tr[2 + j]) != sgn &&
+ if (isl_int_sgn(tr[j]) != sgn &&
var_from_col(tab, j)->is_nonneg)
continue;
if (c < 0 || tab->col_var[j] < tab->col_var[c])
if (c < 0)
return;
- sgn *= isl_int_sgn(tr[2 + c]);
+ sgn *= isl_int_sgn(tr[c]);
r = pivot_row(tab, skip_var, sgn, c);
*row = r < 0 ? var->index : r;
*col = c;
* This means
* - it represents an inequality or a variable
* - that is the sum of a non-negative sample value and a positive
- * combination of zero or more non-negative variables.
+ * combination of zero or more non-negative constraints.
*/
-static int is_redundant(struct isl_tab *tab, int row)
+int isl_tab_row_is_redundant(struct isl_tab *tab, int row)
{
int i;
+ unsigned off = 2 + tab->M;
- if (tab->row_var[row] < 0 && !var_from_row(tab, row)->is_nonneg)
+ if (tab->row_var[row] < 0 && !isl_tab_var_from_row(tab, row)->is_nonneg)
return 0;
if (isl_int_is_neg(tab->mat->row[row][1]))
return 0;
+ if (tab->strict_redundant && isl_int_is_zero(tab->mat->row[row][1]))
+ return 0;
+ if (tab->M && isl_int_is_neg(tab->mat->row[row][2]))
+ return 0;
for (i = tab->n_dead; i < tab->n_col; ++i) {
- if (isl_int_is_zero(tab->mat->row[row][2 + i]))
+ if (isl_int_is_zero(tab->mat->row[row][off + i]))
continue;
- if (isl_int_is_neg(tab->mat->row[row][2 + i]))
+ if (tab->col_var[i] >= 0)
+ return 0;
+ if (isl_int_is_neg(tab->mat->row[row][off + i]))
return 0;
if (!var_from_col(tab, i)->is_nonneg)
return 0;
static void swap_rows(struct isl_tab *tab, int row1, int row2)
{
int t;
+ enum isl_tab_row_sign s;
+
t = tab->row_var[row1];
tab->row_var[row1] = tab->row_var[row2];
tab->row_var[row2] = t;
- var_from_row(tab, row1)->index = row1;
- var_from_row(tab, row2)->index = row2;
+ isl_tab_var_from_row(tab, row1)->index = row1;
+ isl_tab_var_from_row(tab, row2)->index = row2;
tab->mat = isl_mat_swap_rows(tab->mat, row1, row2);
+
+ if (!tab->row_sign)
+ return;
+ s = tab->row_sign[row1];
+ tab->row_sign[row1] = tab->row_sign[row2];
+ tab->row_sign[row2] = s;
}
-static void push(struct isl_tab *tab,
- enum isl_tab_undo_type type, struct isl_tab_var *var)
+static int push_union(struct isl_tab *tab,
+ enum isl_tab_undo_type type, union isl_tab_undo_val u) WARN_UNUSED;
+static int push_union(struct isl_tab *tab,
+ enum isl_tab_undo_type type, union isl_tab_undo_val u)
{
struct isl_tab_undo *undo;
+ if (!tab)
+ return -1;
if (!tab->need_undo)
- return;
+ return 0;
undo = isl_alloc_type(tab->mat->ctx, struct isl_tab_undo);
- if (!undo) {
- free_undo(tab);
- tab->top = NULL;
- return;
- }
+ if (!undo)
+ return -1;
undo->type = type;
- if (!var)
- undo->var_index = 0;
- else if (var->is_row)
- undo->var_index = tab->row_var[var->index];
- else
- undo->var_index = tab->col_var[var->index];
+ undo->u = u;
undo->next = tab->top;
tab->top = undo;
+
+ return 0;
+}
+
+int isl_tab_push_var(struct isl_tab *tab,
+ enum isl_tab_undo_type type, struct isl_tab_var *var)
+{
+ union isl_tab_undo_val u;
+ if (var->is_row)
+ u.var_index = tab->row_var[var->index];
+ else
+ u.var_index = tab->col_var[var->index];
+ return push_union(tab, type, u);
+}
+
+int isl_tab_push(struct isl_tab *tab, enum isl_tab_undo_type type)
+{
+ union isl_tab_undo_val u = { 0 };
+ return push_union(tab, type, u);
+}
+
+/* Push a record on the undo stack describing the current basic
+ * variables, so that the this state can be restored during rollback.
+ */
+int isl_tab_push_basis(struct isl_tab *tab)
+{
+ int i;
+ union isl_tab_undo_val u;
+
+ u.col_var = isl_alloc_array(tab->mat->ctx, int, tab->n_col);
+ if (!u.col_var)
+ return -1;
+ for (i = 0; i < tab->n_col; ++i)
+ u.col_var[i] = tab->col_var[i];
+ return push_union(tab, isl_tab_undo_saved_basis, u);
+}
+
+int isl_tab_push_callback(struct isl_tab *tab, struct isl_tab_callback *callback)
+{
+ union isl_tab_undo_val u;
+ u.callback = callback;
+ return push_union(tab, isl_tab_undo_callback, u);
+}
+
+struct isl_tab *isl_tab_init_samples(struct isl_tab *tab)
+{
+ if (!tab)
+ return NULL;
+
+ tab->n_sample = 0;
+ tab->n_outside = 0;
+ tab->samples = isl_mat_alloc(tab->mat->ctx, 1, 1 + tab->n_var);
+ if (!tab->samples)
+ goto error;
+ tab->sample_index = isl_alloc_array(tab->mat->ctx, int, 1);
+ if (!tab->sample_index)
+ goto error;
+ return tab;
+error:
+ isl_tab_free(tab);
+ return NULL;
+}
+
+struct isl_tab *isl_tab_add_sample(struct isl_tab *tab,
+ __isl_take isl_vec *sample)
+{
+ if (!tab || !sample)
+ goto error;
+
+ if (tab->n_sample + 1 > tab->samples->n_row) {
+ int *t = isl_realloc_array(tab->mat->ctx,
+ tab->sample_index, int, tab->n_sample + 1);
+ if (!t)
+ goto error;
+ tab->sample_index = t;
+ }
+
+ tab->samples = isl_mat_extend(tab->samples,
+ tab->n_sample + 1, tab->samples->n_col);
+ if (!tab->samples)
+ goto error;
+
+ isl_seq_cpy(tab->samples->row[tab->n_sample], sample->el, sample->size);
+ isl_vec_free(sample);
+ tab->sample_index[tab->n_sample] = tab->n_sample;
+ tab->n_sample++;
+
+ return tab;
+error:
+ isl_vec_free(sample);
+ isl_tab_free(tab);
+ return NULL;
+}
+
+struct isl_tab *isl_tab_drop_sample(struct isl_tab *tab, int s)
+{
+ if (s != tab->n_outside) {
+ int t = tab->sample_index[tab->n_outside];
+ tab->sample_index[tab->n_outside] = tab->sample_index[s];
+ tab->sample_index[s] = t;
+ isl_mat_swap_rows(tab->samples, tab->n_outside, s);
+ }
+ tab->n_outside++;
+ if (isl_tab_push(tab, isl_tab_undo_drop_sample) < 0) {
+ isl_tab_free(tab);
+ return NULL;
+ }
+
+ return tab;
+}
+
+/* Record the current number of samples so that we can remove newer
+ * samples during a rollback.
+ */
+int isl_tab_save_samples(struct isl_tab *tab)
+{
+ union isl_tab_undo_val u;
+
+ if (!tab)
+ return -1;
+
+ u.n = tab->n_sample;
+ return push_union(tab, isl_tab_undo_saved_samples, u);
}
/* Mark row with index "row" as being redundant.
* then a return value of 1 means that the row with the given
* row number may now contain a different row that hasn't been checked yet.
*/
-static int mark_redundant(struct isl_tab *tab, int row)
+int isl_tab_mark_redundant(struct isl_tab *tab, int row)
{
- struct isl_tab_var *var = var_from_row(tab, row);
+ 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);
- if (tab->need_undo || tab->row_var[row] >= 0) {
+ isl_assert(tab->mat->ctx, row >= tab->n_redundant, return -1);
+ if (tab->preserve || tab->need_undo || tab->row_var[row] >= 0) {
if (tab->row_var[row] >= 0 && !var->is_nonneg) {
var->is_nonneg = 1;
- push(tab, isl_tab_undo_nonneg, var);
+ if (isl_tab_push_var(tab, isl_tab_undo_nonneg, var) < 0)
+ return -1;
}
if (row != tab->n_redundant)
swap_rows(tab, row, tab->n_redundant);
- push(tab, isl_tab_undo_redundant, var);
tab->n_redundant++;
- return 0;
+ return isl_tab_push_var(tab, isl_tab_undo_redundant, var);
} else {
if (row != tab->n_row - 1)
swap_rows(tab, row, tab->n_row - 1);
- var_from_row(tab, tab->n_row - 1)->index = -1;
+ isl_tab_var_from_row(tab, tab->n_row - 1)->index = -1;
tab->n_row--;
return 1;
}
}
-static struct isl_tab *mark_empty(struct isl_tab *tab)
+int isl_tab_mark_empty(struct isl_tab *tab)
{
+ if (!tab)
+ return -1;
if (!tab->empty && tab->need_undo)
- push(tab, isl_tab_undo_empty, NULL);
+ if (isl_tab_push(tab, isl_tab_undo_empty) < 0)
+ return -1;
tab->empty = 1;
- return tab;
+ return 0;
+}
+
+int isl_tab_freeze_constraint(struct isl_tab *tab, int con)
+{
+ struct isl_tab_var *var;
+
+ if (!tab)
+ return -1;
+
+ var = &tab->con[con];
+ if (var->frozen)
+ return 0;
+ if (var->index < 0)
+ return 0;
+ var->frozen = 1;
+
+ if (tab->need_undo)
+ return isl_tab_push_var(tab, isl_tab_undo_freeze, var);
+
+ return 0;
+}
+
+/* Update the rows signs after a pivot of "row" and "col", with "row_sgn"
+ * the original sign of the pivot element.
+ * We only keep track of row signs during PILP solving and in this case
+ * we only pivot a row with negative sign (meaning the value is always
+ * non-positive) using a positive pivot element.
+ *
+ * For each row j, the new value of the parametric constant is equal to
+ *
+ * a_j0 - a_jc a_r0/a_rc
+ *
+ * where a_j0 is the original parametric constant, a_rc is the pivot element,
+ * a_r0 is the parametric constant of the pivot row and a_jc is the
+ * pivot column entry of the row j.
+ * Since a_r0 is non-positive and a_rc is positive, the sign of row j
+ * remains the same if a_jc has the same sign as the row j or if
+ * a_jc is zero. In all other cases, we reset the sign to "unknown".
+ */
+static void update_row_sign(struct isl_tab *tab, int row, int col, int row_sgn)
+{
+ int i;
+ struct isl_mat *mat = tab->mat;
+ unsigned off = 2 + tab->M;
+
+ if (!tab->row_sign)
+ return;
+
+ if (tab->row_sign[row] == 0)
+ return;
+ isl_assert(mat->ctx, row_sgn > 0, return);
+ isl_assert(mat->ctx, tab->row_sign[row] == isl_tab_row_neg, return);
+ tab->row_sign[row] = isl_tab_row_pos;
+ for (i = 0; i < tab->n_row; ++i) {
+ int s;
+ if (i == row)
+ continue;
+ s = isl_int_sgn(mat->row[i][off + col]);
+ if (!s)
+ continue;
+ if (!tab->row_sign[i])
+ continue;
+ if (s < 0 && tab->row_sign[i] == isl_tab_row_neg)
+ continue;
+ if (s > 0 && tab->row_sign[i] == isl_tab_row_pos)
+ continue;
+ tab->row_sign[i] = isl_tab_row_unknown;
+ }
}
/* Given a row number "row" and a column number "col", pivot the tableau
* s(n_rc)d_r n_jc/(|n_rc| d_j) (n_ji |n_rc| - s(n_rc)n_jc n_ri)/(|n_rc| d_j)
*
*/
-static void pivot(struct isl_tab *tab, int row, int col)
+int isl_tab_pivot(struct isl_tab *tab, int row, int col)
{
int i, j;
int sgn;
int t;
struct isl_mat *mat = tab->mat;
struct isl_tab_var *var;
+ unsigned off = 2 + tab->M;
+
+ if (tab->mat->ctx->abort) {
+ isl_ctx_set_error(tab->mat->ctx, isl_error_abort);
+ return -1;
+ }
- isl_int_swap(mat->row[row][0], mat->row[row][2 + col]);
+ isl_int_swap(mat->row[row][0], mat->row[row][off + col]);
sgn = isl_int_sgn(mat->row[row][0]);
if (sgn < 0) {
isl_int_neg(mat->row[row][0], mat->row[row][0]);
- isl_int_neg(mat->row[row][2 + col], mat->row[row][2 + col]);
+ isl_int_neg(mat->row[row][off + col], mat->row[row][off + col]);
} else
- for (j = 0; j < 1 + tab->n_col; ++j) {
- if (j == 1 + col)
+ for (j = 0; j < off - 1 + tab->n_col; ++j) {
+ if (j == off - 1 + col)
continue;
isl_int_neg(mat->row[row][1 + j], mat->row[row][1 + j]);
}
if (!isl_int_is_one(mat->row[row][0]))
- isl_seq_normalize(mat->row[row], 2 + tab->n_col);
+ isl_seq_normalize(mat->ctx, mat->row[row], off + tab->n_col);
for (i = 0; i < tab->n_row; ++i) {
if (i == row)
continue;
- if (isl_int_is_zero(mat->row[i][2 + col]))
+ if (isl_int_is_zero(mat->row[i][off + col]))
continue;
isl_int_mul(mat->row[i][0], mat->row[i][0], mat->row[row][0]);
- for (j = 0; j < 1 + tab->n_col; ++j) {
- if (j == 1 + col)
+ for (j = 0; j < off - 1 + tab->n_col; ++j) {
+ if (j == off - 1 + col)
continue;
isl_int_mul(mat->row[i][1 + j],
mat->row[i][1 + j], mat->row[row][0]);
isl_int_addmul(mat->row[i][1 + j],
- mat->row[i][2 + col], mat->row[row][1 + j]);
+ mat->row[i][off + col], mat->row[row][1 + j]);
}
- isl_int_mul(mat->row[i][2 + col],
- mat->row[i][2 + col], mat->row[row][2 + col]);
- if (!isl_int_is_one(mat->row[row][0]))
- isl_seq_normalize(mat->row[i], 2 + tab->n_col);
+ isl_int_mul(mat->row[i][off + col],
+ mat->row[i][off + col], mat->row[row][off + col]);
+ if (!isl_int_is_one(mat->row[i][0]))
+ isl_seq_normalize(mat->ctx, mat->row[i], off + tab->n_col);
}
t = tab->row_var[row];
tab->row_var[row] = tab->col_var[col];
tab->col_var[col] = t;
- var = var_from_row(tab, row);
+ var = isl_tab_var_from_row(tab, row);
var->is_row = 1;
var->index = row;
var = var_from_col(tab, col);
var->is_row = 0;
var->index = col;
+ update_row_sign(tab, row, col, sgn);
if (tab->in_undo)
- return;
+ return 0;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- if (isl_int_is_zero(mat->row[i][2 + col]))
+ if (isl_int_is_zero(mat->row[i][off + col]))
continue;
- if (!var_from_row(tab, i)->frozen &&
- is_redundant(tab, i))
- if (mark_redundant(tab, i))
+ if (!isl_tab_var_from_row(tab, i)->frozen &&
+ isl_tab_row_is_redundant(tab, i)) {
+ int redo = isl_tab_mark_redundant(tab, i);
+ if (redo < 0)
+ return -1;
+ if (redo)
--i;
+ }
}
+ return 0;
}
/* If "var" represents a column variable, then pivot is up (sgn > 0)
* If sgn = 0, then the variable is unbounded in both directions,
* and we pivot with any row we can find.
*/
-static void to_row(struct isl_tab *tab, struct isl_tab_var *var, int sign)
+static int to_row(struct isl_tab *tab, struct isl_tab_var *var, int sign) WARN_UNUSED;
+static int to_row(struct isl_tab *tab, struct isl_tab_var *var, int sign)
{
int r;
+ unsigned off = 2 + tab->M;
if (var->is_row)
- return;
+ return 0;
if (sign == 0) {
for (r = tab->n_redundant; r < tab->n_row; ++r)
- if (!isl_int_is_zero(tab->mat->row[r][2 + var->index]))
+ if (!isl_int_is_zero(tab->mat->row[r][off+var->index]))
break;
- isl_assert(tab->mat->ctx, r < tab->n_row, return);
+ isl_assert(tab->mat->ctx, r < tab->n_row, return -1);
} else {
r = pivot_row(tab, NULL, sign, var->index);
- isl_assert(tab->mat->ctx, r >= 0, return);
+ isl_assert(tab->mat->ctx, r >= 0, return -1);
}
- pivot(tab, r, var->index);
+ 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 (tab->empty)
return;
- for (i = 0; i < tab->n_row; ++i) {
- if (!var_from_row(tab, i)->is_nonneg)
+ for (i = tab->n_redundant; i < tab->n_row; ++i) {
+ struct isl_tab_var *var;
+ var = isl_tab_var_from_row(tab, i);
+ if (!var->is_nonneg)
continue;
- assert(!isl_int_is_neg(tab->mat->row[i][1]));
+ if (tab->M) {
+ isl_assert(tab->mat->ctx,
+ !isl_int_is_neg(tab->mat->row[i][2]), abort());
+ if (isl_int_is_pos(tab->mat->row[i][2]))
+ continue;
+ }
+ isl_assert(tab->mat->ctx, !isl_int_is_neg(tab->mat->row[i][1]),
+ abort());
}
}
if (max_is_manifestly_unbounded(tab, var))
return 1;
- to_row(tab, var, 1);
+ if (to_row(tab, var, 1) < 0)
+ return -2;
while (!isl_int_is_pos(tab->mat->row[var->index][1])) {
find_pivot(tab, var, var, 1, &row, &col);
if (row == -1)
return isl_int_sgn(tab->mat->row[var->index][1]);
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -2;
if (!var->is_row) /* manifestly unbounded */
return 1;
}
return 1;
}
-/* Perform pivots until the row variable "var" has a non-negative
- * sample value or until no more upward pivots can be performed.
- * Return the sign of the sample value after the pivots have been
- * performed.
- */
-static int restore_row(struct isl_tab *tab, struct isl_tab_var *var)
+int isl_tab_sign_of_max(struct isl_tab *tab, int con)
{
- int row, col;
+ struct isl_tab_var *var;
- while (isl_int_is_neg(tab->mat->row[var->index][1])) {
- find_pivot(tab, var, var, 1, &row, &col);
- if (row == -1)
- break;
- pivot(tab, row, col);
+ if (!tab)
+ return -2;
+
+ var = &tab->con[con];
+ isl_assert(tab->mat->ctx, !var->is_redundant, return -2);
+ isl_assert(tab->mat->ctx, !var->is_zero, return -2);
+
+ return sign_of_max(tab, var);
+}
+
+static int row_is_neg(struct isl_tab *tab, int row)
+{
+ if (!tab->M)
+ return isl_int_is_neg(tab->mat->row[row][1]);
+ if (isl_int_is_pos(tab->mat->row[row][2]))
+ return 0;
+ if (isl_int_is_neg(tab->mat->row[row][2]))
+ return 1;
+ return isl_int_is_neg(tab->mat->row[row][1]);
+}
+
+static int row_sgn(struct isl_tab *tab, int row)
+{
+ if (!tab->M)
+ return isl_int_sgn(tab->mat->row[row][1]);
+ if (!isl_int_is_zero(tab->mat->row[row][2]))
+ return isl_int_sgn(tab->mat->row[row][2]);
+ else
+ return isl_int_sgn(tab->mat->row[row][1]);
+}
+
+/* Perform pivots until the row variable "var" has a non-negative
+ * sample value or until no more upward pivots can be performed.
+ * Return the sign of the sample value after the pivots have been
+ * performed.
+ */
+static int restore_row(struct isl_tab *tab, struct isl_tab_var *var)
+{
+ int row, col;
+
+ while (row_is_neg(tab, var->index)) {
+ find_pivot(tab, var, var, 1, &row, &col);
+ if (row == -1)
+ break;
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -2;
if (!var->is_row) /* manifestly unbounded */
return 1;
}
- return isl_int_sgn(tab->mat->row[var->index][1]);
+ return row_sgn(tab, var->index);
}
/* Perform pivots until we are sure that the row variable "var"
break;
if (row == var->index) /* manifestly unbounded */
return 1;
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -1;
}
return !isl_int_is_neg(tab->mat->row[var->index][1]);
}
static int sign_of_min(struct isl_tab *tab, struct isl_tab_var *var)
{
int row, col;
- struct isl_tab_var *pivot_var;
+ struct isl_tab_var *pivot_var = NULL;
if (min_is_manifestly_unbounded(tab, var))
return -1;
col = var->index;
row = pivot_row(tab, NULL, -1, col);
pivot_var = var_from_col(tab, col);
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -2;
if (var->is_redundant)
return 0;
if (isl_int_is_neg(tab->mat->row[var->index][1])) {
if (var->is_nonneg) {
if (!pivot_var->is_redundant &&
- pivot_var->index == row)
- pivot(tab, row, col);
- else
- restore_row(tab, var);
+ pivot_var->index == row) {
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -2;
+ } else
+ if (restore_row(tab, var) < -1)
+ return -2;
}
return -1;
}
if (row == -1)
return isl_int_sgn(tab->mat->row[var->index][1]);
pivot_var = var_from_col(tab, col);
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -2;
if (var->is_redundant)
return 0;
}
- if (var->is_nonneg) {
+ if (pivot_var && var->is_nonneg) {
/* pivot back to non-negative value */
- if (!pivot_var->is_redundant && pivot_var->index == row)
- pivot(tab, row, col);
- else
- restore_row(tab, var);
+ if (!pivot_var->is_redundant && pivot_var->index == row) {
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -2;
+ } else
+ if (restore_row(tab, var) < -1)
+ return -2;
}
return -1;
}
+static int row_at_most_neg_one(struct isl_tab *tab, int row)
+{
+ if (tab->M) {
+ if (isl_int_is_pos(tab->mat->row[row][2]))
+ return 0;
+ if (isl_int_is_neg(tab->mat->row[row][2]))
+ return 1;
+ }
+ return isl_int_is_neg(tab->mat->row[row][1]) &&
+ isl_int_abs_ge(tab->mat->row[row][1],
+ tab->mat->row[row][0]);
+}
+
/* Return 1 if "var" can attain values <= -1.
* Return 0 otherwise.
*
* The sample value of "var" is assumed to be non-negative when the
- * the function is called and will be made non-negative again before
+ * the function is called. If 1 is returned then the constraint
+ * is not redundant and the sample value is made non-negative again before
* the function returns.
*/
-static int min_at_most_neg_one(struct isl_tab *tab, struct isl_tab_var *var)
+int isl_tab_min_at_most_neg_one(struct isl_tab *tab, struct isl_tab_var *var)
{
int row, col;
struct isl_tab_var *pivot_var;
col = var->index;
row = pivot_row(tab, NULL, -1, col);
pivot_var = var_from_col(tab, col);
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -1;
if (var->is_redundant)
return 0;
- if (isl_int_is_neg(tab->mat->row[var->index][1]) &&
- isl_int_abs_ge(tab->mat->row[var->index][1],
- tab->mat->row[var->index][0])) {
+ if (row_at_most_neg_one(tab, var->index)) {
if (var->is_nonneg) {
if (!pivot_var->is_redundant &&
- pivot_var->index == row)
- pivot(tab, row, col);
- else
- restore_row(tab, var);
+ pivot_var->index == row) {
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -1;
+ } else
+ if (restore_row(tab, var) < -1)
+ return -1;
}
return 1;
}
return 0;
do {
find_pivot(tab, var, var, -1, &row, &col);
- if (row == var->index)
+ if (row == var->index) {
+ if (restore_row(tab, var) < -1)
+ return -1;
return 1;
+ }
if (row == -1)
return 0;
pivot_var = var_from_col(tab, col);
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -1;
if (var->is_redundant)
return 0;
- } while (!isl_int_is_neg(tab->mat->row[var->index][1]) ||
- isl_int_abs_lt(tab->mat->row[var->index][1],
- tab->mat->row[var->index][0]));
+ } while (!row_at_most_neg_one(tab, var->index));
if (var->is_nonneg) {
/* pivot back to non-negative value */
if (!pivot_var->is_redundant && pivot_var->index == row)
- pivot(tab, row, col);
- restore_row(tab, var);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -1;
+ if (restore_row(tab, var) < -1)
+ return -1;
}
return 1;
}
if (max_is_manifestly_unbounded(tab, var))
return 1;
- to_row(tab, var, 1);
+ if (to_row(tab, var, 1) < 0)
+ return -1;
r = tab->mat->row[var->index];
while (isl_int_lt(r[1], r[0])) {
find_pivot(tab, var, var, 1, &row, &col);
return isl_int_ge(r[1], r[0]);
if (row == var->index) /* manifestly unbounded */
return 1;
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -1;
}
return 1;
}
static void swap_cols(struct isl_tab *tab, int col1, int col2)
{
int t;
+ unsigned off = 2 + tab->M;
t = tab->col_var[col1];
tab->col_var[col1] = tab->col_var[col2];
tab->col_var[col2] = t;
var_from_col(tab, col1)->index = col1;
var_from_col(tab, col2)->index = col2;
- tab->mat = isl_mat_swap_cols(tab->mat, 2 + col1, 2 + col2);
+ tab->mat = isl_mat_swap_cols(tab->mat, off + col1, off + col2);
}
/* Mark column with index "col" as representing a zero variable.
* column number may now contain a different column that
* hasn't been checked yet.
*/
-static int kill_col(struct isl_tab *tab, int col)
+int isl_tab_kill_col(struct isl_tab *tab, int col)
{
var_from_col(tab, col)->is_zero = 1;
if (tab->need_undo) {
- push(tab, isl_tab_undo_zero, var_from_col(tab, col));
+ if (isl_tab_push_var(tab, isl_tab_undo_zero,
+ var_from_col(tab, col)) < 0)
+ return -1;
if (col != tab->n_dead)
swap_cols(tab, col, tab->n_dead);
tab->n_dead++;
}
}
+static int row_is_manifestly_non_integral(struct isl_tab *tab, int row)
+{
+ unsigned off = 2 + tab->M;
+
+ if (tab->M && !isl_int_eq(tab->mat->row[row][2],
+ tab->mat->row[row][0]))
+ return 0;
+ if (isl_seq_first_non_zero(tab->mat->row[row] + off + tab->n_dead,
+ tab->n_col - tab->n_dead) != -1)
+ return 0;
+
+ return !isl_int_is_divisible_by(tab->mat->row[row][1],
+ tab->mat->row[row][0]);
+}
+
+/* For integer tableaus, check if any of the coordinates are stuck
+ * at a non-integral value.
+ */
+static int tab_is_manifestly_empty(struct isl_tab *tab)
+{
+ int i;
+
+ if (tab->empty)
+ return 1;
+ if (tab->rational)
+ return 0;
+
+ for (i = 0; i < tab->n_var; ++i) {
+ if (!tab->var[i].is_row)
+ continue;
+ if (row_is_manifestly_non_integral(tab, tab->var[i].index))
+ return 1;
+ }
+
+ return 0;
+}
+
/* Row variable "var" is non-negative and cannot attain any values
* larger than zero. This means that the coefficients of the unrestricted
* column variables are zero and that the coefficients of the non-negative
* then also be written as the negative sum of non-negative variables
* and must therefore also be zero.
*/
-static void close_row(struct isl_tab *tab, struct isl_tab_var *var)
+static int close_row(struct isl_tab *tab, struct isl_tab_var *var) WARN_UNUSED;
+static int close_row(struct isl_tab *tab, struct isl_tab_var *var)
{
int j;
struct isl_mat *mat = tab->mat;
+ unsigned off = 2 + tab->M;
- isl_assert(tab->mat->ctx, var->is_nonneg, return);
+ isl_assert(tab->mat->ctx, var->is_nonneg, return -1);
var->is_zero = 1;
+ if (tab->need_undo)
+ if (isl_tab_push_var(tab, isl_tab_undo_zero, var) < 0)
+ return -1;
for (j = tab->n_dead; j < tab->n_col; ++j) {
- if (isl_int_is_zero(mat->row[var->index][2 + j]))
+ int recheck;
+ if (isl_int_is_zero(mat->row[var->index][off + j]))
continue;
isl_assert(tab->mat->ctx,
- isl_int_is_neg(mat->row[var->index][2 + j]), return);
- if (kill_col(tab, j))
+ isl_int_is_neg(mat->row[var->index][off + j]), return -1);
+ recheck = isl_tab_kill_col(tab, j);
+ if (recheck < 0)
+ return -1;
+ if (recheck)
--j;
}
- mark_redundant(tab, var->index);
+ if (isl_tab_mark_redundant(tab, var->index) < 0)
+ return -1;
+ if (tab_is_manifestly_empty(tab) && isl_tab_mark_empty(tab) < 0)
+ return -1;
+ return 0;
}
/* Add a constraint to the tableau and allocate a row for it.
* Return the index into the constraint array "con".
*/
-static int allocate_con(struct isl_tab *tab)
+int isl_tab_allocate_con(struct isl_tab *tab)
{
int r;
isl_assert(tab->mat->ctx, tab->n_row < tab->mat->n_row, return -1);
+ isl_assert(tab->mat->ctx, tab->n_con < tab->max_con, return -1);
r = tab->n_con;
tab->con[r].index = tab->n_row;
tab->con[r].is_zero = 0;
tab->con[r].is_redundant = 0;
tab->con[r].frozen = 0;
+ tab->con[r].negated = 0;
tab->row_var[tab->n_row] = ~r;
tab->n_row++;
tab->n_con++;
- push(tab, isl_tab_undo_allocate, &tab->con[r]);
+ if (isl_tab_push_var(tab, isl_tab_undo_allocate, &tab->con[r]) < 0)
+ return -1;
+
+ return r;
+}
+
+/* Add a variable to the tableau and allocate a column for it.
+ * Return the index into the variable array "var".
+ */
+int isl_tab_allocate_var(struct isl_tab *tab)
+{
+ int r;
+ int i;
+ unsigned off = 2 + tab->M;
+
+ isl_assert(tab->mat->ctx, tab->n_col < tab->mat->n_col, return -1);
+ isl_assert(tab->mat->ctx, tab->n_var < tab->max_var, return -1);
+
+ r = tab->n_var;
+ tab->var[r].index = tab->n_col;
+ tab->var[r].is_row = 0;
+ tab->var[r].is_nonneg = 0;
+ tab->var[r].is_zero = 0;
+ tab->var[r].is_redundant = 0;
+ tab->var[r].frozen = 0;
+ tab->var[r].negated = 0;
+ tab->col_var[tab->n_col] = r;
+
+ for (i = 0; i < tab->n_row; ++i)
+ isl_int_set_si(tab->mat->row[i][off + tab->n_col], 0);
+
+ tab->n_var++;
+ tab->n_col++;
+ if (isl_tab_push_var(tab, isl_tab_undo_allocate, &tab->var[r]) < 0)
+ return -1;
return r;
}
* d_r d_r d_r d_x/g m
*
* with g the gcd of d_r and d_x and m the lcm of d_r and d_x.
+ *
+ * If tab->M is set, then, internally, each variable x is represented
+ * as x' - M. We then also need no subtract k d_r from the coefficient of M.
*/
-static int add_row(struct isl_tab *tab, isl_int *line)
+int isl_tab_add_row(struct isl_tab *tab, isl_int *line)
{
int i;
int r;
isl_int *row;
isl_int a, b;
+ unsigned off = 2 + tab->M;
- r = allocate_con(tab);
+ r = isl_tab_allocate_con(tab);
if (r < 0)
return -1;
row = tab->mat->row[tab->con[r].index];
isl_int_set_si(row[0], 1);
isl_int_set(row[1], line[0]);
- isl_seq_clr(row + 2, tab->n_col);
+ isl_seq_clr(row + 2, tab->M + tab->n_col);
for (i = 0; i < tab->n_var; ++i) {
if (tab->var[i].is_zero)
continue;
isl_int_mul(b, b, line[1 + i]);
isl_seq_combine(row + 1, a, row + 1,
b, tab->mat->row[tab->var[i].index] + 1,
- 1 + tab->n_col);
+ 1 + tab->M + tab->n_col);
} else
- isl_int_addmul(row[2 + tab->var[i].index],
+ isl_int_addmul(row[off + tab->var[i].index],
line[1 + i], row[0]);
+ if (tab->M && i >= tab->n_param && i < tab->n_var - tab->n_div)
+ isl_int_submul(row[2], line[1 + i], row[0]);
}
- isl_seq_normalize(row, 2 + tab->n_col);
+ isl_seq_normalize(tab->mat->ctx, row, off + tab->n_col);
isl_int_clear(a);
isl_int_clear(b);
+ if (tab->row_sign)
+ tab->row_sign[tab->con[r].index] = isl_tab_row_unknown;
+
return r;
}
return 0;
}
+static int drop_col(struct isl_tab *tab, int col)
+{
+ isl_assert(tab->mat->ctx, tab->col_var[col] == tab->n_var - 1, return -1);
+ if (col != tab->n_col - 1)
+ swap_cols(tab, col, tab->n_col - 1);
+ tab->n_col--;
+ tab->n_var--;
+ return 0;
+}
+
/* Add inequality "ineq" and check if it conflicts with the
* previously added constraints or if it is obviously redundant.
*/
-struct isl_tab *isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq)
+int isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq)
{
int r;
int sgn;
+ isl_int cst;
if (!tab)
- return NULL;
- r = add_row(tab, ineq);
+ return -1;
+ if (tab->bmap) {
+ struct isl_basic_map *bmap = tab->bmap;
+
+ isl_assert(tab->mat->ctx, tab->n_eq == bmap->n_eq, return -1);
+ isl_assert(tab->mat->ctx,
+ tab->n_con == bmap->n_eq + bmap->n_ineq, return -1);
+ tab->bmap = isl_basic_map_add_ineq(tab->bmap, ineq);
+ if (isl_tab_push(tab, isl_tab_undo_bmap_ineq) < 0)
+ return -1;
+ if (!tab->bmap)
+ return -1;
+ }
+ if (tab->cone) {
+ isl_int_init(cst);
+ isl_int_swap(ineq[0], cst);
+ }
+ r = isl_tab_add_row(tab, ineq);
+ if (tab->cone) {
+ isl_int_swap(ineq[0], cst);
+ isl_int_clear(cst);
+ }
if (r < 0)
- goto error;
+ return -1;
tab->con[r].is_nonneg = 1;
- push(tab, isl_tab_undo_nonneg, &tab->con[r]);
- if (is_redundant(tab, tab->con[r].index)) {
- mark_redundant(tab, tab->con[r].index);
- return tab;
+ if (isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]) < 0)
+ return -1;
+ if (isl_tab_row_is_redundant(tab, tab->con[r].index)) {
+ if (isl_tab_mark_redundant(tab, tab->con[r].index) < 0)
+ return -1;
+ return 0;
}
sgn = restore_row(tab, &tab->con[r]);
+ if (sgn < -1)
+ return -1;
if (sgn < 0)
- return mark_empty(tab);
- if (tab->con[r].is_row && is_redundant(tab, tab->con[r].index))
- mark_redundant(tab, tab->con[r].index);
- return tab;
-error:
- isl_tab_free(tab);
- return NULL;
+ return isl_tab_mark_empty(tab);
+ if (tab->con[r].is_row && isl_tab_row_is_redundant(tab, tab->con[r].index))
+ if (isl_tab_mark_redundant(tab, tab->con[r].index) < 0)
+ return -1;
+ return 0;
}
/* Pivot a non-negative variable down until it reaches the value zero
* and then pivot the variable into a column position.
*/
+static int to_col(struct isl_tab *tab, struct isl_tab_var *var) WARN_UNUSED;
static int to_col(struct isl_tab *tab, struct isl_tab_var *var)
{
int i;
int row, col;
+ unsigned off = 2 + tab->M;
if (!var->is_row)
- return;
+ return 0;
while (isl_int_is_pos(tab->mat->row[var->index][1])) {
find_pivot(tab, var, NULL, -1, &row, &col);
isl_assert(tab->mat->ctx, row != -1, return -1);
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return -1;
if (!var->is_row)
- return;
+ return 0;
}
for (i = tab->n_dead; i < tab->n_col; ++i)
- if (!isl_int_is_zero(tab->mat->row[var->index][2 + i]))
+ if (!isl_int_is_zero(tab->mat->row[var->index][off + i]))
break;
isl_assert(tab->mat->ctx, i < tab->n_col, return -1);
- pivot(tab, var->index, i);
+ if (isl_tab_pivot(tab, var->index, i) < 0)
+ return -1;
return 0;
}
if (!tab)
return NULL;
- r = add_row(tab, eq);
+ r = isl_tab_add_row(tab, eq);
if (r < 0)
goto error;
r = tab->con[r].index;
- i = isl_seq_first_non_zero(tab->mat->row[r] + 2 + tab->n_dead,
+ i = isl_seq_first_non_zero(tab->mat->row[r] + 2 + tab->M + tab->n_dead,
tab->n_col - tab->n_dead);
isl_assert(tab->mat->ctx, i >= 0, goto error);
i += tab->n_dead;
- pivot(tab, r, i);
- kill_col(tab, i);
+ if (isl_tab_pivot(tab, r, i) < 0)
+ goto error;
+ if (isl_tab_kill_col(tab, i) < 0)
+ goto error;
tab->n_eq++;
return tab;
return NULL;
}
+static int row_is_manifestly_zero(struct isl_tab *tab, int row)
+{
+ unsigned off = 2 + tab->M;
+
+ if (!isl_int_is_zero(tab->mat->row[row][1]))
+ return 0;
+ if (tab->M && !isl_int_is_zero(tab->mat->row[row][2]))
+ return 0;
+ return isl_seq_first_non_zero(tab->mat->row[row] + off + tab->n_dead,
+ tab->n_col - tab->n_dead) == -1;
+}
+
/* Add an equality that is known to be valid for the given tableau.
*/
-struct isl_tab *isl_tab_add_valid_eq(struct isl_tab *tab, isl_int *eq)
+int isl_tab_add_valid_eq(struct isl_tab *tab, isl_int *eq)
{
struct isl_tab_var *var;
- int i;
int r;
if (!tab)
- return NULL;
- r = add_row(tab, eq);
+ return -1;
+ r = isl_tab_add_row(tab, eq);
if (r < 0)
- goto error;
+ return -1;
var = &tab->con[r];
r = var->index;
- if (isl_int_is_neg(tab->mat->row[r][1]))
+ if (row_is_manifestly_zero(tab, r)) {
+ var->is_zero = 1;
+ if (isl_tab_mark_redundant(tab, r) < 0)
+ return -1;
+ return 0;
+ }
+
+ if (isl_int_is_neg(tab->mat->row[r][1])) {
isl_seq_neg(tab->mat->row[r] + 1, tab->mat->row[r] + 1,
1 + tab->n_col);
+ var->negated = 1;
+ }
var->is_nonneg = 1;
if (to_col(tab, var) < 0)
- goto error;
+ return -1;
var->is_nonneg = 0;
- kill_col(tab, var->index);
+ if (isl_tab_kill_col(tab, var->index) < 0)
+ return -1;
- return tab;
+ return 0;
+}
+
+static int add_zero_row(struct isl_tab *tab)
+{
+ int r;
+ isl_int *row;
+
+ r = isl_tab_allocate_con(tab);
+ if (r < 0)
+ return -1;
+
+ row = tab->mat->row[tab->con[r].index];
+ isl_seq_clr(row + 1, 1 + tab->M + tab->n_col);
+ isl_int_set_si(row[0], 1);
+
+ return r;
+}
+
+/* Add equality "eq" and check if it conflicts with the
+ * previously added constraints or if it is obviously redundant.
+ */
+int isl_tab_add_eq(struct isl_tab *tab, isl_int *eq)
+{
+ struct isl_tab_undo *snap = NULL;
+ struct isl_tab_var *var;
+ int r;
+ int row;
+ int sgn;
+ isl_int cst;
+
+ if (!tab)
+ return -1;
+ isl_assert(tab->mat->ctx, !tab->M, return -1);
+
+ if (tab->need_undo)
+ snap = isl_tab_snap(tab);
+
+ if (tab->cone) {
+ isl_int_init(cst);
+ isl_int_swap(eq[0], cst);
+ }
+ r = isl_tab_add_row(tab, eq);
+ if (tab->cone) {
+ isl_int_swap(eq[0], cst);
+ isl_int_clear(cst);
+ }
+ if (r < 0)
+ return -1;
+
+ var = &tab->con[r];
+ row = var->index;
+ if (row_is_manifestly_zero(tab, row)) {
+ if (snap) {
+ if (isl_tab_rollback(tab, snap) < 0)
+ return -1;
+ } else
+ drop_row(tab, row);
+ return 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)
+ return -1;
+ isl_seq_neg(eq, eq, 1 + tab->n_var);
+ 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_bmap_ineq) < 0)
+ return -1;
+ if (!tab->bmap)
+ return -1;
+ if (add_zero_row(tab) < 0)
+ return -1;
+ }
+
+ sgn = isl_int_sgn(tab->mat->row[row][1]);
+
+ if (sgn > 0) {
+ isl_seq_neg(tab->mat->row[row] + 1, tab->mat->row[row] + 1,
+ 1 + tab->n_col);
+ var->negated = 1;
+ sgn = -1;
+ }
+
+ if (sgn < 0) {
+ sgn = sign_of_max(tab, var);
+ if (sgn < -1)
+ return -1;
+ if (sgn < 0) {
+ if (isl_tab_mark_empty(tab) < 0)
+ return -1;
+ return 0;
+ }
+ }
+
+ var->is_nonneg = 1;
+ if (to_col(tab, var) < 0)
+ return -1;
+ var->is_nonneg = 0;
+ if (isl_tab_kill_col(tab, var->index) < 0)
+ return -1;
+
+ return 0;
+}
+
+/* Construct and return an inequality that expresses an upper bound
+ * on the given div.
+ * In particular, if the div is given by
+ *
+ * d = floor(e/m)
+ *
+ * then the inequality expresses
+ *
+ * m d <= e
+ */
+static struct isl_vec *ineq_for_div(struct isl_basic_map *bmap, unsigned div)
+{
+ unsigned total;
+ unsigned div_pos;
+ struct isl_vec *ineq;
+
+ if (!bmap)
+ return NULL;
+
+ total = isl_basic_map_total_dim(bmap);
+ div_pos = 1 + total - bmap->n_div + div;
+
+ ineq = isl_vec_alloc(bmap->ctx, 1 + total);
+ if (!ineq)
+ return NULL;
+
+ isl_seq_cpy(ineq->el, bmap->div[div] + 1, 1 + total);
+ isl_int_neg(ineq->el[div_pos], bmap->div[div][0]);
+ return ineq;
+}
+
+/* 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
+ *
+ * If add_ineq is not NULL, then this function is used
+ * instead of isl_tab_add_ineq to effectively add the inequalities.
+ */
+static int add_div_constraints(struct isl_tab *tab, unsigned div,
+ int (*add_ineq)(void *user, isl_int *), void *user)
+{
+ unsigned total;
+ unsigned div_pos;
+ struct isl_vec *ineq;
+
+ total = isl_basic_map_total_dim(tab->bmap);
+ div_pos = 1 + total - tab->bmap->n_div + div;
+
+ ineq = ineq_for_div(tab->bmap, div);
+ if (!ineq)
+ goto error;
+
+ if (add_ineq) {
+ if (add_ineq(user, ineq->el) < 0)
+ goto error;
+ } else {
+ if (isl_tab_add_ineq(tab, ineq->el) < 0)
+ goto error;
+ }
+
+ isl_seq_neg(ineq->el, tab->bmap->div[div] + 1, 1 + total);
+ isl_int_set(ineq->el[div_pos], tab->bmap->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);
+
+ if (add_ineq) {
+ if (add_ineq(user, ineq->el) < 0)
+ goto error;
+ } else {
+ if (isl_tab_add_ineq(tab, ineq->el) < 0)
+ goto error;
+ }
+
+ isl_vec_free(ineq);
+
+ return 0;
error:
- isl_tab_free(tab);
- return NULL;
+ isl_vec_free(ineq);
+ return -1;
}
-struct isl_tab *isl_tab_from_basic_map(struct isl_basic_map *bmap)
+/* Check whether the div described by "div" is obviously non-negative.
+ * If we are using a big parameter, then we will encode the div
+ * as div' = M + div, which is always non-negative.
+ * Otherwise, we check whether div is a non-negative affine combination
+ * of non-negative variables.
+ */
+static int div_is_nonneg(struct isl_tab *tab, __isl_keep isl_vec *div)
+{
+ int i;
+
+ if (tab->M)
+ return 1;
+
+ if (isl_int_is_neg(div->el[1]))
+ return 0;
+
+ for (i = 0; i < tab->n_var; ++i) {
+ if (isl_int_is_neg(div->el[2 + i]))
+ return 0;
+ if (isl_int_is_zero(div->el[2 + i]))
+ continue;
+ if (!tab->var[i].is_nonneg)
+ return 0;
+ }
+
+ return 1;
+}
+
+/* Add an extra div, prescribed by "div" to the tableau and
+ * the associated bmap (which is assumed to be non-NULL).
+ *
+ * If add_ineq is not NULL, then this function is used instead
+ * of isl_tab_add_ineq to add the div constraints.
+ * This complication is needed because the code in isl_tab_pip
+ * wants to perform some extra processing when an inequality
+ * is added to the tableau.
+ */
+int isl_tab_add_div(struct isl_tab *tab, __isl_keep isl_vec *div,
+ int (*add_ineq)(void *user, isl_int *), void *user)
+{
+ int r;
+ int k;
+ int nonneg;
+
+ if (!tab || !div)
+ return -1;
+
+ isl_assert(tab->mat->ctx, tab->bmap, return -1);
+
+ nonneg = div_is_nonneg(tab, div);
+
+ 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);
+ if (r < 0)
+ return -1;
+
+ if (nonneg)
+ tab->var[r].is_nonneg = 1;
+
+ 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;
+ isl_seq_cpy(tab->bmap->div[k], div->el, div->size);
+ if (isl_tab_push(tab, isl_tab_undo_bmap_div) < 0)
+ return -1;
+
+ if (add_div_constraints(tab, k, add_ineq, user) < 0)
+ return -1;
+
+ return r;
+}
+
+/* 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;
return NULL;
tab = isl_tab_alloc(bmap->ctx,
isl_basic_map_total_dim(bmap) + bmap->n_ineq + 1,
- isl_basic_map_total_dim(bmap));
+ 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))
- return mark_empty(tab);
+ if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY)) {
+ if (isl_tab_mark_empty(tab) < 0)
+ goto error;
+ goto done;
+ }
for (i = 0; i < bmap->n_eq; ++i) {
tab = add_eq(tab, bmap->eq[i]);
if (!tab)
return tab;
}
for (i = 0; i < bmap->n_ineq; ++i) {
- tab = isl_tab_add_ineq(tab, bmap->ineq[i]);
- if (!tab || tab->empty)
- return tab;
+ if (isl_tab_add_ineq(tab, bmap->ineq[i]) < 0)
+ goto error;
+ if (tab->empty)
+ 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 "bmap".
+/* Construct a tableau corresponding to the recession cone of "bset".
*/
-struct isl_tab *isl_tab_from_recession_cone(struct isl_basic_map *bmap)
+struct isl_tab *isl_tab_from_recession_cone(__isl_keep isl_basic_set *bset,
+ int parametric)
{
isl_int cst;
int i;
struct isl_tab *tab;
+ unsigned offset = 0;
- if (!bmap)
+ if (!bset)
return NULL;
- tab = isl_tab_alloc(bmap->ctx, bmap->n_eq + bmap->n_ineq,
- isl_basic_map_total_dim(bmap));
+ if (parametric)
+ offset = isl_basic_set_dim(bset, isl_dim_param);
+ tab = isl_tab_alloc(bset->ctx, bset->n_eq + bset->n_ineq,
+ isl_basic_set_total_dim(bset) - offset, 0);
if (!tab)
return NULL;
- tab->rational = ISL_F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL);
+ tab->rational = ISL_F_ISSET(bset, ISL_BASIC_SET_RATIONAL);
+ tab->cone = 1;
isl_int_init(cst);
- for (i = 0; i < bmap->n_eq; ++i) {
- isl_int_swap(bmap->eq[i][0], cst);
- tab = add_eq(tab, bmap->eq[i]);
- isl_int_swap(bmap->eq[i][0], cst);
+ for (i = 0; i < bset->n_eq; ++i) {
+ isl_int_swap(bset->eq[i][offset], cst);
+ if (offset > 0) {
+ if (isl_tab_add_eq(tab, bset->eq[i] + offset) < 0)
+ goto error;
+ } else
+ tab = add_eq(tab, bset->eq[i]);
+ isl_int_swap(bset->eq[i][offset], cst);
if (!tab)
goto done;
}
- for (i = 0; i < bmap->n_ineq; ++i) {
+ for (i = 0; i < bset->n_ineq; ++i) {
int r;
- isl_int_swap(bmap->ineq[i][0], cst);
- r = add_row(tab, bmap->ineq[i]);
- isl_int_swap(bmap->ineq[i][0], cst);
+ isl_int_swap(bset->ineq[i][offset], cst);
+ r = isl_tab_add_row(tab, bset->ineq[i] + offset);
+ isl_int_swap(bset->ineq[i][offset], cst);
if (r < 0)
goto error;
tab->con[r].is_nonneg = 1;
- push(tab, isl_tab_undo_nonneg, &tab->con[r]);
+ if (isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]) < 0)
+ goto error;
}
done:
isl_int_clear(cst);
for (;;) {
for (i = tab->n_redundant; i < tab->n_row; ++i) {
struct isl_tab_var *var;
- var = var_from_row(tab, i);
+ int sgn;
+ var = isl_tab_var_from_row(tab, i);
if (!var->is_nonneg)
continue;
- if (sign_of_max(tab, var) != 0)
+ sgn = sign_of_max(tab, var);
+ if (sgn < -1)
+ return -1;
+ if (sgn != 0)
return 0;
- close_row(tab, var);
+ if (close_row(tab, var) < 0)
+ return -1;
break;
}
if (tab->n_dead == tab->n_col)
isl_int_divexact(m, vec->block.data[0], tab->mat->row[row][0]);
isl_int_mul(vec->block.data[1 + i], m, tab->mat->row[row][1]);
}
- isl_seq_normalize(vec->block.data, vec->size);
+ vec = isl_vec_normalize(vec);
isl_int_clear(m);
return vec;
else if (isl_tab_is_redundant(tab, n_eq + i))
isl_basic_map_drop_inequality(bmap, i);
}
+ if (bmap->n_eq != n_eq)
+ isl_basic_map_gauss(bmap, NULL);
if (!tab->rational &&
!bmap->sample && isl_tab_sample_is_integer(tab))
bmap->sample = extract_integer_sample(tab);
* the resulting tableau is empty.
* Otherwise, we know the value will be zero and we close the row.
*/
-static struct isl_tab *cut_to_hyperplane(struct isl_tab *tab,
- struct isl_tab_var *var)
+static int cut_to_hyperplane(struct isl_tab *tab, struct isl_tab_var *var)
{
unsigned r;
isl_int *row;
int sgn;
+ unsigned off = 2 + tab->M;
+
+ if (var->is_zero)
+ return 0;
+ isl_assert(tab->mat->ctx, !var->is_redundant, return -1);
+ isl_assert(tab->mat->ctx, var->is_nonneg, return -1);
- if (extend_cons(tab, 1) < 0)
- goto error;
+ if (isl_tab_extend_cons(tab, 1) < 0)
+ return -1;
r = tab->n_con;
tab->con[r].index = tab->n_row;
tab->con[r].is_zero = 0;
tab->con[r].is_redundant = 0;
tab->con[r].frozen = 0;
+ tab->con[r].negated = 0;
tab->row_var[tab->n_row] = ~r;
row = tab->mat->row[tab->n_row];
} else {
isl_int_set_si(row[0], 1);
isl_seq_clr(row + 1, 1 + tab->n_col);
- isl_int_set_si(row[2 + var->index], -1);
+ isl_int_set_si(row[off + var->index], -1);
}
tab->n_row++;
tab->n_con++;
- push(tab, isl_tab_undo_allocate, &tab->con[r]);
+ if (isl_tab_push_var(tab, isl_tab_undo_allocate, &tab->con[r]) < 0)
+ return -1;
sgn = sign_of_max(tab, &tab->con[r]);
- if (sgn < 0)
- return mark_empty(tab);
+ if (sgn < -1)
+ return -1;
+ if (sgn < 0) {
+ if (isl_tab_mark_empty(tab) < 0)
+ return -1;
+ return 0;
+ }
tab->con[r].is_nonneg = 1;
- push(tab, isl_tab_undo_nonneg, &tab->con[r]);
+ if (isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]) < 0)
+ return -1;
/* sgn == 0 */
- close_row(tab, &tab->con[r]);
+ if (close_row(tab, &tab->con[r]) < 0)
+ return -1;
- return tab;
-error:
- isl_tab_free(tab);
- return NULL;
+ return 0;
}
/* Given a tableau "tab" and an inequality constraint "con" of the tableau,
* If r is a column variable, then we need to modify each row that
* refers to r = r' - 1 by substituting this equality, effectively
* subtracting the coefficient of the column from the constant.
+ * We should only do this if the minimum is manifestly unbounded,
+ * however. Otherwise, we may end up with negative sample values
+ * for non-negative variables.
+ * So, if r is a column variable with a minimum that is not
+ * manifestly unbounded, then we need to move it to a row.
+ * However, the sample value of this row may be negative,
+ * even after the relaxation, so we need to restore it.
+ * We therefore prefer to pivot a column up to a row, if possible.
*/
struct isl_tab *isl_tab_relax(struct isl_tab *tab, int con)
{
struct isl_tab_var *var;
+ unsigned off = 2 + tab->M;
+
if (!tab)
return NULL;
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))
- to_row(tab, var, 1);
+ if (to_row(tab, var, 1) < 0)
+ goto error;
+ if (!var->is_row && !min_is_manifestly_unbounded(tab, var))
+ if (to_row(tab, var, -1) < 0)
+ goto error;
- if (var->is_row)
+ if (var->is_row) {
isl_int_add(tab->mat->row[var->index][1],
tab->mat->row[var->index][1], tab->mat->row[var->index][0]);
- else {
+ if (restore_row(tab, var) < 0)
+ goto error;
+ } else {
int i;
for (i = 0; i < tab->n_row; ++i) {
- if (isl_int_is_zero(tab->mat->row[i][2 + var->index]))
+ if (isl_int_is_zero(tab->mat->row[i][off + var->index]))
continue;
isl_int_sub(tab->mat->row[i][1], tab->mat->row[i][1],
- tab->mat->row[i][2 + var->index]);
+ tab->mat->row[i][off + var->index]);
}
}
- push(tab, isl_tab_undo_relax, var);
+ if (isl_tab_push_var(tab, isl_tab_undo_relax, var) < 0)
+ goto error;
return tab;
+error:
+ isl_tab_free(tab);
+ return NULL;
+}
+
+/* Remove the sign constraint from constraint "con".
+ *
+ * If the constraint variable was originally marked non-negative,
+ * then we make sure we mark it non-negative again during rollback.
+ */
+int isl_tab_unrestrict(struct isl_tab *tab, int con)
+{
+ struct isl_tab_var *var;
+
+ if (!tab)
+ return -1;
+
+ var = &tab->con[con];
+ if (!var->is_nonneg)
+ return 0;
+
+ var->is_nonneg = 0;
+ if (isl_tab_push_var(tab, isl_tab_undo_unrestrict, var) < 0)
+ return -1;
+
+ return 0;
}
-struct isl_tab *isl_tab_select_facet(struct isl_tab *tab, int con)
+int isl_tab_select_facet(struct isl_tab *tab, int con)
{
if (!tab)
- return NULL;
+ return -1;
return cut_to_hyperplane(tab, &tab->con[con]);
}
static int may_be_equality(struct isl_tab *tab, int row)
{
- return (tab->rational ? isl_int_is_zero(tab->mat->row[row][1])
- : isl_int_lt(tab->mat->row[row][1],
- tab->mat->row[row][0])) &&
- isl_seq_first_non_zero(tab->mat->row[row] + 2 + tab->n_dead,
- tab->n_col - tab->n_dead) != -1;
+ return tab->rational ? isl_int_is_zero(tab->mat->row[row][1])
+ : isl_int_lt(tab->mat->row[row][1],
+ tab->mat->row[row][0]);
}
/* Check for (near) equalities among the constraints.
* tableau is integer), then we restrict the value to being zero
* by adding an opposite non-negative variable.
*/
-struct isl_tab *isl_tab_detect_equalities(struct isl_tab *tab)
+int isl_tab_detect_implicit_equalities(struct isl_tab *tab)
{
int i;
unsigned n_marked;
if (!tab)
- return NULL;
+ return -1;
if (tab->empty)
- return tab;
+ return 0;
if (tab->n_dead == tab->n_col)
- return tab;
+ return 0;
n_marked = 0;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- struct isl_tab_var *var = var_from_row(tab, i);
+ struct isl_tab_var *var = isl_tab_var_from_row(tab, i);
var->marked = !var->frozen && var->is_nonneg &&
may_be_equality(tab, i);
if (var->marked)
}
while (n_marked) {
struct isl_tab_var *var;
+ int sgn;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- var = var_from_row(tab, i);
+ var = isl_tab_var_from_row(tab, i);
if (var->marked)
break;
}
}
var->marked = 0;
n_marked--;
- if (sign_of_max(tab, var) == 0)
- close_row(tab, var);
- else if (!tab->rational && !at_least_one(tab, var)) {
- tab = cut_to_hyperplane(tab, var);
- return isl_tab_detect_equalities(tab);
+ sgn = sign_of_max(tab, var);
+ if (sgn < 0)
+ return -1;
+ if (sgn == 0) {
+ if (close_row(tab, var) < 0)
+ return -1;
+ } else if (!tab->rational && !at_least_one(tab, var)) {
+ if (cut_to_hyperplane(tab, var) < 0)
+ return -1;
+ return isl_tab_detect_implicit_equalities(tab);
}
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- var = var_from_row(tab, i);
+ var = isl_tab_var_from_row(tab, i);
if (!var->marked)
continue;
if (may_be_equality(tab, i))
}
}
- return tab;
+ 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)
+ return -1;
+ if (tab->rational) {
+ int sgn = sign_of_min(tab, var);
+ if (sgn < -1)
+ return -1;
+ return sgn >= 0;
+ } else {
+ int irred = isl_tab_min_at_most_neg_one(tab, var);
+ if (irred < 0)
+ return -1;
+ return !irred;
+ }
}
/* Check for (near) redundant constraints.
* If not, we mark the row as being redundant (assuming it hasn't
* been detected as being obviously redundant in the mean time).
*/
-struct isl_tab *isl_tab_detect_redundant(struct isl_tab *tab)
+int isl_tab_detect_redundant(struct isl_tab *tab)
{
int i;
unsigned n_marked;
if (!tab)
- return NULL;
+ return -1;
if (tab->empty)
- return tab;
+ return 0;
if (tab->n_redundant == tab->n_row)
- return tab;
+ return 0;
n_marked = 0;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- struct isl_tab_var *var = var_from_row(tab, i);
+ struct isl_tab_var *var = isl_tab_var_from_row(tab, i);
var->marked = !var->frozen && var->is_nonneg;
if (var->marked)
n_marked++;
}
while (n_marked) {
struct isl_tab_var *var;
+ int red;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
- var = var_from_row(tab, i);
+ var = isl_tab_var_from_row(tab, i);
if (var->marked)
break;
}
}
var->marked = 0;
n_marked--;
- if ((tab->rational ? (sign_of_min(tab, var) >= 0)
- : !min_at_most_neg_one(tab, var)) &&
- !var->is_redundant)
- mark_redundant(tab, var->index);
+ red = con_is_redundant(tab, var);
+ if (red < 0)
+ return -1;
+ if (red && !var->is_redundant)
+ if (isl_tab_mark_redundant(tab, var->index) < 0)
+ return -1;
for (i = tab->n_dead; i < tab->n_col; ++i) {
var = var_from_col(tab, i);
if (!var->marked)
}
}
- return tab;
+ return 0;
}
int isl_tab_is_equality(struct isl_tab *tab, int con)
{
int row;
+ unsigned off;
if (!tab)
return -1;
row = tab->con[con].index;
+ off = 2 + tab->M;
return isl_int_is_zero(tab->mat->row[row][1]) &&
- isl_seq_first_non_zero(tab->mat->row[row] + 2 + tab->n_dead,
+ (!tab->M || isl_int_is_zero(tab->mat->row[row][2])) &&
+ isl_seq_first_non_zero(tab->mat->row[row] + off + tab->n_dead,
tab->n_col - tab->n_dead) == -1;
}
-/* Return the minimial value of the affine expression "f" with denominator
+/* Return the minimal value of the affine expression "f" with denominator
* "denom" in *opt, *opt_denom, assuming the tableau is not empty and
* the expression cannot attain arbitrarily small values.
* If opt_denom is NULL, then *opt is rounded up to the nearest integer.
* The return value reflects the nature of the result (empty, unbounded,
- * minmimal value returned in *opt).
+ * minimal value returned in *opt).
*/
enum isl_lp_result isl_tab_min(struct isl_tab *tab,
isl_int *f, isl_int denom, isl_int *opt, isl_int *opt_denom,
struct isl_tab_var *var;
struct isl_tab_undo *snap;
+ if (!tab)
+ return isl_lp_error;
+
if (tab->empty)
return isl_lp_empty;
snap = isl_tab_snap(tab);
- r = add_row(tab, f);
+ r = isl_tab_add_row(tab, f);
if (r < 0)
return isl_lp_error;
var = &tab->con[r];
- isl_int_mul(tab->mat->row[var->index][0],
- tab->mat->row[var->index][0], denom);
for (;;) {
int row, col;
find_pivot(tab, var, var, -1, &row, &col);
}
if (row == -1)
break;
- pivot(tab, row, col);
+ if (isl_tab_pivot(tab, row, col) < 0)
+ return isl_lp_error;
}
- if (isl_tab_rollback(tab, snap) < 0)
- return isl_lp_error;
+ isl_int_mul(tab->mat->row[var->index][0],
+ tab->mat->row[var->index][0], denom);
if (ISL_FL_ISSET(flags, ISL_TAB_SAVE_DUAL)) {
int i;
return isl_lp_error;
isl_int_set(tab->dual->el[0], tab->mat->row[var->index][0]);
for (i = 0; i < tab->n_con; ++i) {
- if (tab->con[i].is_row)
+ int pos;
+ if (tab->con[i].is_row) {
isl_int_set_si(tab->dual->el[1 + i], 0);
- else {
- int pos = 2 + tab->con[i].index;
+ continue;
+ }
+ pos = 2 + tab->M + tab->con[i].index;
+ if (tab->con[i].negated)
+ isl_int_neg(tab->dual->el[1 + i],
+ tab->mat->row[var->index][pos]);
+ else
isl_int_set(tab->dual->el[1 + i],
tab->mat->row[var->index][pos]);
- }
}
}
- if (res == isl_lp_ok) {
+ if (opt && res == isl_lp_ok) {
if (opt_denom) {
isl_int_set(*opt, tab->mat->row[var->index][1]);
isl_int_set(*opt_denom, tab->mat->row[var->index][0]);
isl_int_cdiv_q(*opt, tab->mat->row[var->index][1],
tab->mat->row[var->index][0]);
}
+ if (isl_tab_rollback(tab, snap) < 0)
+ return isl_lp_error;
return res;
}
int isl_tab_is_redundant(struct isl_tab *tab, int con)
{
- int row;
- unsigned n_col;
-
if (!tab)
return -1;
if (tab->con[con].is_zero)
/* Undo the operation performed by isl_tab_relax.
*/
-static void unrelax(struct isl_tab *tab, struct isl_tab_var *var)
+static int unrelax(struct isl_tab *tab, struct isl_tab_var *var) WARN_UNUSED;
+static int unrelax(struct isl_tab *tab, struct isl_tab_var *var)
{
+ unsigned off = 2 + tab->M;
+
if (!var->is_row && !max_is_manifestly_unbounded(tab, var))
- to_row(tab, var, 1);
+ if (to_row(tab, var, 1) < 0)
+ return -1;
- if (var->is_row)
+ if (var->is_row) {
isl_int_sub(tab->mat->row[var->index][1],
tab->mat->row[var->index][1], tab->mat->row[var->index][0]);
- else {
+ if (var->is_nonneg) {
+ int sgn = restore_row(tab, var);
+ isl_assert(tab->mat->ctx, sgn >= 0, return -1);
+ }
+ } else {
int i;
for (i = 0; i < tab->n_row; ++i) {
- if (isl_int_is_zero(tab->mat->row[i][2 + var->index]))
+ if (isl_int_is_zero(tab->mat->row[i][off + var->index]))
continue;
isl_int_add(tab->mat->row[i][1], tab->mat->row[i][1],
- tab->mat->row[i][2 + var->index]);
+ tab->mat->row[i][off + var->index]);
}
}
+
+ return 0;
+}
+
+/* Undo the operation performed by isl_tab_unrestrict.
+ *
+ * In particular, mark the variable as being non-negative and make
+ * sure the sample value respects this constraint.
+ */
+static int ununrestrict(struct isl_tab *tab, struct isl_tab_var *var)
+{
+ var->is_nonneg = 1;
+
+ if (var->is_row && restore_row(tab, var) < -1)
+ return -1;
+
+ return 0;
}
-static void perform_undo(struct isl_tab *tab, struct isl_tab_undo *undo)
+static int perform_undo_var(struct isl_tab *tab, struct isl_tab_undo *undo) WARN_UNUSED;
+static int perform_undo_var(struct isl_tab *tab, struct isl_tab_undo *undo)
{
- struct isl_tab_var *var = var_from_index(tab, undo->var_index);
- switch(undo->type) {
- case isl_tab_undo_empty:
- tab->empty = 0;
- break;
+ struct isl_tab_var *var = var_from_index(tab, undo->u.var_index);
+ switch (undo->type) {
case isl_tab_undo_nonneg:
var->is_nonneg = 0;
break;
case isl_tab_undo_redundant:
var->is_redundant = 0;
tab->n_redundant--;
+ restore_row(tab, isl_tab_var_from_row(tab, tab->n_redundant));
+ break;
+ case isl_tab_undo_freeze:
+ var->frozen = 0;
break;
case isl_tab_undo_zero:
var->is_zero = 0;
- tab->n_dead--;
+ if (!var->is_row)
+ tab->n_dead--;
break;
case isl_tab_undo_allocate:
+ if (undo->u.var_index >= 0) {
+ isl_assert(tab->mat->ctx, !var->is_row, return -1);
+ drop_col(tab, var->index);
+ break;
+ }
if (!var->is_row) {
- if (!max_is_manifestly_unbounded(tab, var))
- to_row(tab, var, 1);
- else if (!min_is_manifestly_unbounded(tab, var))
- to_row(tab, var, -1);
- else
- to_row(tab, var, 0);
+ if (!max_is_manifestly_unbounded(tab, var)) {
+ if (to_row(tab, var, 1) < 0)
+ return -1;
+ } else if (!min_is_manifestly_unbounded(tab, var)) {
+ if (to_row(tab, var, -1) < 0)
+ return -1;
+ } else
+ if (to_row(tab, var, 0) < 0)
+ return -1;
}
drop_row(tab, var->index);
break;
case isl_tab_undo_relax:
- unrelax(tab, var);
+ return unrelax(tab, var);
+ case isl_tab_undo_unrestrict:
+ return ununrestrict(tab, var);
+ default:
+ isl_die(tab->mat->ctx, isl_error_internal,
+ "perform_undo_var called on invalid undo record",
+ return -1);
+ }
+
+ return 0;
+}
+
+/* Restore the tableau to the state where the basic variables
+ * are those in "col_var".
+ * We first construct a list of variables that are currently in
+ * the basis, but shouldn't. Then we iterate over all variables
+ * that should be in the basis and for each one that is currently
+ * not in the basis, we exchange it with one of the elements of the
+ * list constructed before.
+ * We can always find an appropriate variable to pivot with because
+ * the current basis is mapped to the old basis by a non-singular
+ * matrix and so we can never end up with a zero row.
+ */
+static int restore_basis(struct isl_tab *tab, int *col_var)
+{
+ int i, j;
+ int n_extra = 0;
+ int *extra = NULL; /* current columns that contain bad stuff */
+ unsigned off = 2 + tab->M;
+
+ extra = isl_alloc_array(tab->mat->ctx, int, tab->n_col);
+ if (!extra)
+ goto error;
+ for (i = 0; i < tab->n_col; ++i) {
+ for (j = 0; j < tab->n_col; ++j)
+ if (tab->col_var[i] == col_var[j])
+ break;
+ if (j < tab->n_col)
+ continue;
+ extra[n_extra++] = i;
+ }
+ for (i = 0; i < tab->n_col && n_extra > 0; ++i) {
+ struct isl_tab_var *var;
+ int row;
+
+ for (j = 0; j < tab->n_col; ++j)
+ if (col_var[i] == tab->col_var[j])
+ break;
+ if (j < tab->n_col)
+ continue;
+ var = var_from_index(tab, col_var[i]);
+ row = var->index;
+ for (j = 0; j < n_extra; ++j)
+ if (!isl_int_is_zero(tab->mat->row[row][off+extra[j]]))
+ break;
+ isl_assert(tab->mat->ctx, j < n_extra, goto error);
+ if (isl_tab_pivot(tab, row, extra[j]) < 0)
+ goto error;
+ extra[j] = extra[--n_extra];
+ }
+
+ free(extra);
+ return 0;
+error:
+ free(extra);
+ return -1;
+}
+
+/* Remove all samples with index n or greater, i.e., those samples
+ * that were added since we saved this number of samples in
+ * isl_tab_save_samples.
+ */
+static void drop_samples_since(struct isl_tab *tab, int n)
+{
+ int i;
+
+ for (i = tab->n_sample - 1; i >= 0 && tab->n_sample > n; --i) {
+ if (tab->sample_index[i] < n)
+ continue;
+
+ if (i != tab->n_sample - 1) {
+ int t = tab->sample_index[tab->n_sample-1];
+ tab->sample_index[tab->n_sample-1] = tab->sample_index[i];
+ tab->sample_index[i] = t;
+ isl_mat_swap_rows(tab->samples, tab->n_sample-1, i);
+ }
+ tab->n_sample--;
+ }
+}
+
+static int perform_undo(struct isl_tab *tab, struct isl_tab_undo *undo) WARN_UNUSED;
+static int perform_undo(struct isl_tab *tab, struct isl_tab_undo *undo)
+{
+ switch (undo->type) {
+ case isl_tab_undo_empty:
+ tab->empty = 0;
+ break;
+ case isl_tab_undo_nonneg:
+ case isl_tab_undo_redundant:
+ case isl_tab_undo_freeze:
+ case isl_tab_undo_zero:
+ case isl_tab_undo_allocate:
+ case isl_tab_undo_relax:
+ case isl_tab_undo_unrestrict:
+ return perform_undo_var(tab, undo);
+ case isl_tab_undo_bmap_eq:
+ return isl_basic_map_free_equality(tab->bmap, 1);
+ case isl_tab_undo_bmap_ineq:
+ return isl_basic_map_free_inequality(tab->bmap, 1);
+ case isl_tab_undo_bmap_div:
+ if (isl_basic_map_free_div(tab->bmap, 1) < 0)
+ return -1;
+ if (tab->samples)
+ tab->samples->n_col--;
break;
+ case isl_tab_undo_saved_basis:
+ if (restore_basis(tab, undo->u.col_var) < 0)
+ return -1;
+ break;
+ case isl_tab_undo_drop_sample:
+ tab->n_outside--;
+ break;
+ case isl_tab_undo_saved_samples:
+ drop_samples_since(tab, undo->u.n);
+ break;
+ case isl_tab_undo_callback:
+ return undo->u.callback->run(undo->u.callback);
+ default:
+ isl_assert(tab->mat->ctx, 0, return -1);
}
+ return 0;
}
/* Return the tableau to the state it was in when the snapshot "snap"
next = undo->next;
if (undo == snap)
break;
- perform_undo(tab, undo);
- free(undo);
+ if (perform_undo(tab, undo) < 0) {
+ tab->top = undo;
+ free_undo(tab);
+ tab->in_undo = 0;
+ return -1;
+ }
+ free_undo_record(undo);
}
tab->in_undo = 0;
tab->top = undo;
* In particular, if the row has been reduced to the constant -1,
* then we know the inequality is adjacent (but opposite) to
* an equality in the tableau.
- * If the row has been reduced to r = -1 -r', with r' an inequality
- * of the tableau, then the inequality is adjacent (but opposite)
- * to the inequality r'.
+ * If the row has been reduced to r = c*(-1 -r'), with r' an inequality
+ * of the tableau and c a positive constant, then the inequality
+ * is adjacent (but opposite) to the inequality r'.
*/
static enum isl_ineq_type separation_type(struct isl_tab *tab, unsigned row)
{
int pos;
+ unsigned off = 2 + tab->M;
if (tab->rational)
return isl_ineq_separate;
if (!isl_int_is_one(tab->mat->row[row][0]))
return isl_ineq_separate;
- if (!isl_int_is_negone(tab->mat->row[row][1]))
- return isl_ineq_separate;
- pos = isl_seq_first_non_zero(tab->mat->row[row] + 2 + tab->n_dead,
+ pos = isl_seq_first_non_zero(tab->mat->row[row] + off + tab->n_dead,
tab->n_col - tab->n_dead);
- if (pos == -1)
- return isl_ineq_adj_eq;
+ if (pos == -1) {
+ if (isl_int_is_negone(tab->mat->row[row][1]))
+ return isl_ineq_adj_eq;
+ else
+ return isl_ineq_separate;
+ }
- if (!isl_int_is_negone(tab->mat->row[row][2 + tab->n_dead + pos]))
+ if (!isl_int_eq(tab->mat->row[row][1],
+ tab->mat->row[row][off + tab->n_dead + pos]))
return isl_ineq_separate;
pos = isl_seq_first_non_zero(
- tab->mat->row[row] + 2 + tab->n_dead + pos + 1,
+ tab->mat->row[row] + off + tab->n_dead + pos + 1,
tab->n_col - tab->n_dead - pos - 1);
return pos == -1 ? isl_ineq_adj_ineq : isl_ineq_separate;
if (!tab)
return isl_ineq_error;
- if (extend_cons(tab, 1) < 0)
+ if (isl_tab_extend_cons(tab, 1) < 0)
return isl_ineq_error;
snap = isl_tab_snap(tab);
- con = add_row(tab, ineq);
+ con = isl_tab_add_row(tab, ineq);
if (con < 0)
goto error;
row = tab->con[con].index;
- if (is_redundant(tab, row))
+ if (isl_tab_row_is_redundant(tab, row))
type = isl_ineq_redundant;
else if (isl_int_is_neg(tab->mat->row[row][1]) &&
(tab->rational ||
isl_int_abs_ge(tab->mat->row[row][1],
tab->mat->row[row][0]))) {
- if (at_least_zero(tab, &tab->con[con]))
+ int nonneg = at_least_zero(tab, &tab->con[con]);
+ if (nonneg < 0)
+ goto error;
+ if (nonneg)
type = isl_ineq_cut;
else
type = separation_type(tab, row);
- } else if (tab->rational ? (sign_of_min(tab, &tab->con[con]) < 0)
- : min_at_most_neg_one(tab, &tab->con[con]))
- type = isl_ineq_cut;
- else
- type = isl_ineq_redundant;
+ } else {
+ int red = con_is_redundant(tab, &tab->con[con]);
+ if (red < 0)
+ goto error;
+ if (!red)
+ type = isl_ineq_cut;
+ else
+ type = isl_ineq_redundant;
+ }
if (isl_tab_rollback(tab, snap))
return isl_ineq_error;
return type;
error:
- isl_tab_rollback(tab, snap);
return isl_ineq_error;
}
-void isl_tab_dump(struct isl_tab *tab, FILE *out, int indent)
+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;
+
+ 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, goto error);
+
+ tab->bmap = bmap;
+
+ return 0;
+error:
+ isl_basic_map_free(bmap);
+ return -1;
+}
+
+int isl_tab_track_bset(struct isl_tab *tab, __isl_take isl_basic_set *bset)
+{
+ return isl_tab_track_bmap(tab, (isl_basic_map *)bset);
+}
+
+__isl_keep isl_basic_set *isl_tab_peek_bset(struct isl_tab *tab)
+{
+ if (!tab)
+ return NULL;
+
+ return (isl_basic_set *)tab->bmap;
+}
+
+static void isl_tab_print_internal(__isl_keep struct isl_tab *tab,
+ FILE *out, int indent)
{
unsigned r, c;
int i;
fprintf(out, "%*s[", indent, "");
for (i = 0; i < tab->n_var; ++i) {
if (i)
- fprintf(out, ", ");
+ fprintf(out, (i == tab->n_param ||
+ i == tab->n_var - tab->n_div) ? "; "
+ : ", ");
fprintf(out, "%c%d%s", tab->var[i].is_row ? 'r' : 'c',
tab->var[i].index,
tab->var[i].is_zero ? " [=0]" :
fprintf(out, "]\n");
fprintf(out, "%*s[", indent, "");
for (i = 0; i < tab->n_row; ++i) {
+ const char *sign = "";
if (i)
fprintf(out, ", ");
- fprintf(out, "r%d: %d%s", i, tab->row_var[i],
- var_from_row(tab, i)->is_nonneg ? " [>=0]" : "");
+ if (tab->row_sign) {
+ if (tab->row_sign[i] == isl_tab_row_unknown)
+ sign = "?";
+ else if (tab->row_sign[i] == isl_tab_row_neg)
+ sign = "-";
+ else if (tab->row_sign[i] == isl_tab_row_pos)
+ sign = "+";
+ else
+ sign = "+-";
+ }
+ fprintf(out, "r%d: %d%s%s", i, tab->row_var[i],
+ isl_tab_var_from_row(tab, i)->is_nonneg ? " [>=0]" : "", sign);
}
fprintf(out, "]\n");
fprintf(out, "%*s[", indent, "");
r = tab->mat->n_row;
tab->mat->n_row = tab->n_row;
c = tab->mat->n_col;
- tab->mat->n_col = 2 + tab->n_col;
- isl_mat_dump(tab->mat, out, indent);
+ tab->mat->n_col = 2 + tab->M + tab->n_col;
+ isl_mat_print_internal(tab->mat, out, indent);
tab->mat->n_row = r;
tab->mat->n_col = c;
+ if (tab->bmap)
+ isl_basic_map_print_internal(tab->bmap, out, indent);
+}
+
+void isl_tab_dump(__isl_keep struct isl_tab *tab)
+{
+ isl_tab_print_internal(tab, stderr, 0);
}
projects / platform / upstream / isl.git / blobdiff