+#include "isl_mat.h"
#include "isl_map_private.h"
#include "isl_tab.h"
tab->max_con = n_row;
tab->n_col = n_var;
tab->n_var = n_var;
+ tab->n_param = 0;
+ tab->n_div = 0;
tab->n_dead = 0;
tab->n_redundant = 0;
tab->need_undo = 0;
return NULL;
}
-static int extend_cons(struct isl_tab *tab, unsigned n_new)
+int isl_tab_extend_cons(struct isl_tab *tab, unsigned n_new)
{
if (tab->max_con < tab->n_con + n_new) {
struct isl_tab_var *con;
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);
free(tab);
}
+struct isl_tab *isl_tab_dup(struct isl_tab *tab)
+{
+ int i;
+ struct isl_tab *dup;
+
+ if (!tab)
+ return NULL;
+
+ dup = isl_calloc_type(tab->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);
+ 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);
+ 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);
+ if (!dup->col_var)
+ goto error;
+ for (i = 0; i < tab->n_var; ++i)
+ dup->col_var[i] = tab->col_var[i];
+ dup->row_var = isl_alloc_array(tab->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];
+ 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->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->need_undo = 0;
+ dup->in_undo = 0;
+ dup->bottom.type = isl_tab_undo_bottom;
+ dup->bottom.next = NULL;
+ dup->top = &dup->bottom;
+ return dup;
+error:
+ isl_tab_free(dup);
+ 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]);
}
for (i = tab->n_redundant; i < tab->n_row; ++i) {
if (!isl_int_is_neg(tab->mat->row[i][2 + 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;
for (i = tab->n_redundant; i < tab->n_row; ++i) {
if (!isl_int_is_pos(tab->mat->row[i][2 + 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;
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)
continue;
* - that is the sum of a non-negative sample value and a positive
* combination of zero or more non-negative variables.
*/
-static int is_redundant(struct isl_tab *tab, int row)
+int isl_tab_row_is_redundant(struct isl_tab *tab, int row)
{
int i;
- 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]))
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);
}
-static void push(struct isl_tab *tab,
- enum isl_tab_undo_type type, struct isl_tab_var *var)
+static void push_union(struct isl_tab *tab,
+ enum isl_tab_undo_type type, union isl_tab_undo_val u)
{
struct isl_tab_undo *undo;
return;
}
undo->type = type;
- undo->var = var;
+ undo->u = u;
undo->next = tab->top;
tab->top = undo;
}
+void 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];
+ push_union(tab, type, u);
+}
+
+void isl_tab_push(struct isl_tab *tab, enum isl_tab_undo_type type)
+{
+ union isl_tab_undo_val u = { 0 };
+ 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.
+ */
+void 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) {
+ free_undo(tab);
+ tab->top = NULL;
+ return;
+ }
+ for (i = 0; i < tab->n_col; ++i)
+ u.col_var[i] = tab->col_var[i];
+ push_union(tab, isl_tab_undo_saved_basis, u);
+}
+
/* Mark row with index "row" as being redundant.
* If we may need to undo the operation or if the row represents
* a variable of the original problem, the row is kept,
* 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) {
- if (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);
+ isl_tab_push_var(tab, isl_tab_undo_nonneg, var);
}
if (row != tab->n_redundant)
swap_rows(tab, row, tab->n_redundant);
- push(tab, isl_tab_undo_redundant, var);
+ isl_tab_push_var(tab, isl_tab_undo_redundant, var);
tab->n_redundant++;
return 0;
} 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 void mark_empty(struct isl_tab *tab)
+struct isl_tab *isl_tab_mark_empty(struct isl_tab *tab)
{
if (!tab->empty && tab->need_undo)
- push(tab, isl_tab_undo_empty, NULL);
+ isl_tab_push(tab, isl_tab_undo_empty);
tab->empty = 1;
+ return tab;
}
/* 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)
+void isl_tab_pivot(struct isl_tab *tab, int row, int col)
{
int i, j;
int sgn;
}
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]))
+ if (!isl_int_is_one(mat->row[i][0]))
isl_seq_normalize(mat->row[i], 2 + 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);
for (i = tab->n_redundant; i < tab->n_row; ++i) {
if (isl_int_is_zero(mat->row[i][2 + 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))
+ if (isl_tab_mark_redundant(tab, i))
--i;
}
}
/* If "var" represents a column variable, then pivot is up (sgn > 0)
* or down (sgn < 0) to a row. The variable is assumed not to be
* unbounded in the specified direction.
+ * 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)
{
if (var->is_row)
return;
- r = pivot_row(tab, NULL, sign, var->index);
- isl_assert(tab->mat->ctx, r >= 0, return);
- pivot(tab, r, var->index);
+ 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]))
+ break;
+ isl_assert(tab->mat->ctx, r < tab->n_row, return);
+ } else {
+ r = pivot_row(tab, NULL, sign, var->index);
+ isl_assert(tab->mat->ctx, r >= 0, return);
+ }
+
+ isl_tab_pivot(tab, r, var->index);
}
static void check_table(struct isl_tab *tab)
if (tab->empty)
return;
for (i = 0; i < tab->n_row; ++i) {
- if (!var_from_row(tab, i)->is_nonneg)
+ if (!isl_tab_var_from_row(tab, i)->is_nonneg)
continue;
assert(!isl_int_is_neg(tab->mat->row[i][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);
+ isl_tab_pivot(tab, row, col);
if (!var->is_row) /* manifestly unbounded */
return 1;
}
find_pivot(tab, var, var, 1, &row, &col);
if (row == -1)
break;
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
if (!var->is_row) /* manifestly unbounded */
return 1;
}
break;
if (row == var->index) /* manifestly unbounded */
return 1;
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
}
return !isl_int_is_neg(tab->mat->row[var->index][1]);
}
col = var->index;
row = pivot_row(tab, NULL, -1, col);
pivot_var = var_from_col(tab, col);
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
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);
+ isl_tab_pivot(tab, row, col);
else
restore_row(tab, var);
}
if (row == -1)
return isl_int_sgn(tab->mat->row[var->index][1]);
pivot_var = var_from_col(tab, col);
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
if (var->is_redundant)
return 0;
}
if (var->is_nonneg) {
/* pivot back to non-negative value */
if (!pivot_var->is_redundant && pivot_var->index == row)
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
else
restore_row(tab, var);
}
* the function is called and will be 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);
+ isl_tab_pivot(tab, row, col);
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);
+ isl_tab_pivot(tab, row, col);
else
restore_row(tab, var);
}
if (row == -1)
return 0;
pivot_var = var_from_col(tab, col);
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
if (var->is_redundant)
return 0;
} while (!isl_int_is_neg(tab->mat->row[var->index][1]) ||
if (var->is_nonneg) {
/* pivot back to non-negative value */
if (!pivot_var->is_redundant && pivot_var->index == row)
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
restore_row(tab, var);
}
return 1;
return isl_int_ge(r[1], r[0]);
if (row == var->index) /* manifestly unbounded */
return 1;
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
}
return 1;
}
* 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));
+ isl_tab_push_var(tab, isl_tab_undo_zero, var_from_col(tab, col));
if (col != tab->n_dead)
swap_cols(tab, col, tab->n_dead);
tab->n_dead++;
continue;
isl_assert(tab->mat->ctx,
isl_int_is_neg(mat->row[var->index][2 + j]), return);
- if (kill_col(tab, j))
+ if (isl_tab_kill_col(tab, j))
--j;
}
- mark_redundant(tab, var->index);
+ isl_tab_mark_redundant(tab, var->index);
}
/* 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;
tab->n_row++;
tab->n_con++;
- push(tab, isl_tab_undo_allocate, &tab->con[r]);
+ isl_tab_push_var(tab, isl_tab_undo_allocate, &tab->con[r]);
return r;
}
*
* with g the gcd of d_r and d_x and m the lcm of d_r and d_x.
*/
-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;
- r = allocate_con(tab);
+ r = isl_tab_allocate_con(tab);
if (r < 0)
return -1;
if (!tab)
return NULL;
- r = add_row(tab, ineq);
+ r = isl_tab_add_row(tab, ineq);
if (r < 0)
goto error;
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);
+ isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]);
+ if (isl_tab_row_is_redundant(tab, tab->con[r].index)) {
+ isl_tab_mark_redundant(tab, tab->con[r].index);
return tab;
}
sgn = restore_row(tab, &tab->con[r]);
if (sgn < 0)
- mark_empty(tab);
- else if (tab->con[r].is_row &&
- is_redundant(tab, tab->con[r].index))
- mark_redundant(tab, tab->con[r].index);
+ return isl_tab_mark_empty(tab);
+ if (tab->con[r].is_row && isl_tab_row_is_redundant(tab, tab->con[r].index))
+ isl_tab_mark_redundant(tab, tab->con[r].index);
return tab;
error:
isl_tab_free(tab);
/* 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)
+int to_col(struct isl_tab *tab, struct isl_tab_var *var)
{
int i;
int row, col;
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);
+ isl_tab_pivot(tab, row, col);
if (!var->is_row)
return;
}
break;
isl_assert(tab->mat->ctx, i < tab->n_col, return -1);
- pivot(tab, var->index, i);
+ isl_tab_pivot(tab, var->index, i);
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;
- for (i = tab->n_dead; i < tab->n_col; ++i) {
- if (isl_int_is_zero(tab->mat->row[r][2 + i]))
- continue;
- pivot(tab, r, i);
- kill_col(tab, i);
- break;
- }
+ i = isl_seq_first_non_zero(tab->mat->row[r] + 2 + tab->n_dead,
+ tab->n_col - tab->n_dead);
+ isl_assert(tab->mat->ctx, i >= 0, goto error);
+ i += tab->n_dead;
+ isl_tab_pivot(tab, r, i);
+ isl_tab_kill_col(tab, i);
tab->n_eq++;
return tab;
if (!tab)
return NULL;
- r = add_row(tab, eq);
+ r = isl_tab_add_row(tab, eq);
if (r < 0)
goto error;
if (to_col(tab, var) < 0)
goto error;
var->is_nonneg = 0;
- kill_col(tab, var->index);
+ isl_tab_kill_col(tab, var->index);
return tab;
error:
if (!tab)
return NULL;
tab->rational = ISL_F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL);
- if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY)) {
- mark_empty(tab);
- return tab;
- }
+ if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
+ return isl_tab_mark_empty(tab);
for (i = 0; i < bmap->n_eq; ++i) {
tab = add_eq(tab, bmap->eq[i]);
if (!tab)
for (i = 0; i < bmap->n_ineq; ++i) {
int r;
isl_int_swap(bmap->ineq[i][0], cst);
- r = add_row(tab, bmap->ineq[i]);
+ r = isl_tab_add_row(tab, bmap->ineq[i]);
isl_int_swap(bmap->ineq[i][0], cst);
if (r < 0)
goto error;
tab->con[r].is_nonneg = 1;
- push(tab, isl_tab_undo_nonneg, &tab->con[r]);
+ isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]);
}
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);
+ var = isl_tab_var_from_row(tab, i);
if (!var->is_nonneg)
continue;
if (sign_of_max(tab, var) != 0)
isl_int *row;
int sgn;
- if (extend_cons(tab, 1) < 0)
+ if (isl_tab_extend_cons(tab, 1) < 0)
goto error;
r = tab->n_con;
tab->n_row++;
tab->n_con++;
- push(tab, isl_tab_undo_allocate, &tab->con[r]);
+ isl_tab_push_var(tab, isl_tab_undo_allocate, &tab->con[r]);
sgn = sign_of_max(tab, &tab->con[r]);
if (sgn < 0)
- mark_empty(tab);
- else {
- tab->con[r].is_nonneg = 1;
- push(tab, isl_tab_undo_nonneg, &tab->con[r]);
- /* sgn == 0 */
- close_row(tab, &tab->con[r]);
- }
+ return isl_tab_mark_empty(tab);
+ tab->con[r].is_nonneg = 1;
+ isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]);
+ /* sgn == 0 */
+ close_row(tab, &tab->con[r]);
return tab;
error:
}
- push(tab, isl_tab_undo_relax, var);
+ isl_tab_push_var(tab, isl_tab_undo_relax, var);
return tab;
}
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;
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;
}
return isl_tab_detect_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))
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;
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)) &&
+ : !isl_tab_min_at_most_neg_one(tab, var)) &&
!var->is_redundant)
- mark_redundant(tab, var->index);
+ isl_tab_mark_redundant(tab, var->index);
for (i = tab->n_dead; i < tab->n_col; ++i) {
var = var_from_col(tab, i);
if (!var->marked)
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];
}
if (row == -1)
break;
- pivot(tab, row, col);
+ isl_tab_pivot(tab, row, col);
}
if (isl_tab_rollback(tab, snap) < 0)
return isl_lp_error;
}
}
-static void perform_undo(struct isl_tab *tab, struct isl_tab_undo *undo)
+static void 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) {
- case isl_tab_undo_empty:
- tab->empty = 0;
- break;
case isl_tab_undo_nonneg:
- undo->var->is_nonneg = 0;
+ var->is_nonneg = 0;
break;
case isl_tab_undo_redundant:
- undo->var->is_redundant = 0;
+ var->is_redundant = 0;
tab->n_redundant--;
break;
case isl_tab_undo_zero:
- undo->var->is_zero = 0;
+ var->is_zero = 0;
tab->n_dead--;
break;
case isl_tab_undo_allocate:
- if (!undo->var->is_row) {
- if (max_is_manifestly_unbounded(tab, undo->var))
- to_row(tab, undo->var, -1);
+ 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, undo->var, 1);
+ to_row(tab, var, 0);
}
- drop_row(tab, undo->var->index);
+ drop_row(tab, var->index);
+ break;
+ case isl_tab_undo_relax:
+ unrelax(tab, var);
+ break;
+ }
+}
+
+/* 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;
+
+ 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);
+ isl_tab_pivot(tab, row, extra[j]);
+ extra[j] = extra[--n_extra];
+ }
+
+ free(extra);
+ free(col_var);
+ return 0;
+error:
+ free(extra);
+ free(col_var);
+ return -1;
+}
+
+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_zero:
+ case isl_tab_undo_allocate:
case isl_tab_undo_relax:
- unrelax(tab, undo->var);
+ perform_undo_var(tab, undo);
break;
+ case isl_tab_undo_saved_basis:
+ if (restore_basis(tab, undo->u.col_var) < 0)
+ return -1;
+ break;
+ 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);
+ if (perform_undo(tab, undo) < 0) {
+ free_undo(tab);
+ tab->in_undo = 0;
+ return -1;
+ }
free(undo);
}
tab->in_undo = 0;
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 ||
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]))
+ : isl_tab_min_at_most_neg_one(tab, &tab->con[con]))
type = isl_ineq_cut;
else
type = isl_ineq_redundant;
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]" :
if (i)
fprintf(out, ", ");
fprintf(out, "r%d: %d%s", i, tab->row_var[i],
- var_from_row(tab, i)->is_nonneg ? " [>=0]" : "");
+ isl_tab_var_from_row(tab, i)->is_nonneg ? " [>=0]" : "");
}
fprintf(out, "]\n");
fprintf(out, "%*s[", indent, "");
projects / platform / upstream / isl.git / blobdiff