Merge branch 'maint'
[isl.git] / isl_tab.h
blobe37b7e2df5aab5ca2bb7d454d335bcab8b24406d
1 /*
2 * Copyright 2008-2009 Katholieke Universiteit Leuven
4 * Use of this software is governed by the MIT license
6 * Written by Sven Verdoolaege, K.U.Leuven, Departement
7 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
8 */
10 #ifndef ISL_TAB_H
11 #define ISL_TAB_H
13 #include <isl/lp.h>
14 #include <isl/map.h>
15 #include <isl/mat.h>
16 #include <isl/set.h>
18 struct isl_tab_var {
19 int index;
20 unsigned is_row : 1;
21 unsigned is_nonneg : 1;
22 unsigned is_zero : 1;
23 unsigned is_redundant : 1;
24 unsigned marked : 1;
25 unsigned frozen : 1;
26 unsigned negated : 1;
29 enum isl_tab_undo_type {
30 isl_tab_undo_bottom,
31 isl_tab_undo_empty,
32 isl_tab_undo_nonneg,
33 isl_tab_undo_redundant,
34 isl_tab_undo_freeze,
35 isl_tab_undo_zero,
36 isl_tab_undo_allocate,
37 isl_tab_undo_relax,
38 isl_tab_undo_unrestrict,
39 isl_tab_undo_bmap_ineq,
40 isl_tab_undo_bmap_eq,
41 isl_tab_undo_bmap_div,
42 isl_tab_undo_saved_basis,
43 isl_tab_undo_drop_sample,
44 isl_tab_undo_saved_samples,
45 isl_tab_undo_callback,
48 struct isl_tab_callback {
49 int (*run)(struct isl_tab_callback *cb);
52 union isl_tab_undo_val {
53 int var_index;
54 int *col_var;
55 int n;
56 struct isl_tab_callback *callback;
59 struct isl_tab_undo {
60 enum isl_tab_undo_type type;
61 union isl_tab_undo_val u;
62 struct isl_tab_undo *next;
65 /* The tableau maintains equality relations.
66 * Each column and each row is associated to a variable or a constraint.
67 * The "value" of an inequality constraint is the value of the corresponding
68 * slack variable.
69 * The "row_var" and "col_var" arrays map column and row indices
70 * to indices in the "var" and "con" arrays. The elements of these
71 * arrays maintain extra information about the variables and the constraints.
72 * Each row expresses the corresponding row variable as an affine expression
73 * of the column variables.
74 * The first two columns in the matrix contain the common denominator of
75 * the row and the numerator of the constant term.
76 * If "M" is set, then the third column represents the "big parameter".
77 * The third (M = 0) or fourth (M = 1) column
78 * in the matrix is called column 0 with respect to the col_var array.
79 * The sample value of the tableau is the value that assigns zero
80 * to all the column variables and the constant term of each affine
81 * expression to the corresponding row variable.
82 * The operations on the tableau maintain the property that the sample
83 * value satisfies the non-negativity constraints (usually on the slack
84 * variables).
86 * The big parameter represents an arbitrarily big (and divisible)
87 * positive number. If present, then the sign of a row is determined
88 * lexicographically, with the sign of the big parameter coefficient
89 * considered first. The big parameter is only used while
90 * solving PILP problems.
92 * The first n_dead column variables have their values fixed to zero.
93 * The corresponding tab_vars are flagged "is_zero".
94 * Some of the rows that have have zero coefficients in all but
95 * the dead columns are also flagged "is_zero".
97 * The first n_redundant rows correspond to inequality constraints
98 * that are always satisfied for any value satisfying the non-redundant
99 * rows. The corresponding tab_vars are flagged "is_redundant".
100 * A row variable that is flagged "is_zero" is also flagged "is_redundant"
101 * since the constraint has been reduced to 0 = 0 and is therefore always
102 * satisfied.
104 * There are "n_var" variables in total. The first "n_param" of these
105 * are called parameters and the last "n_div" of these are called divs.
106 * The basic tableau operations makes no distinction between different
107 * kinds of variables. These special variables are only used while
108 * solving PILP problems.
110 * Dead columns and redundant rows are detected on the fly.
111 * However, the basic operations do not ensure that all dead columns
112 * or all redundant rows are detected.
113 * isl_tab_detect_implicit_equalities and isl_tab_detect_redundant can be used
114 * to perform and exhaustive search for dead columns and redundant rows.
116 * The samples matrix contains "n_sample" integer points that have at some
117 * point been elements satisfying the tableau. The first "n_outside"
118 * of them no longer satisfy the tableau. They are kept because they
119 * can be reinstated during rollback when the constraint that cut them
120 * out is removed. These samples are only maintained for the context
121 * tableau while solving PILP problems.
123 * If "preserve" is set, then we want to keep all constraints in the
124 * tableau, even if they turn out to be redundant.
126 enum isl_tab_row_sign {
127 isl_tab_row_unknown = 0,
128 isl_tab_row_pos,
129 isl_tab_row_neg,
130 isl_tab_row_any,
132 struct isl_tab {
133 struct isl_mat *mat;
135 unsigned n_row;
136 unsigned n_col;
137 unsigned n_dead;
138 unsigned n_redundant;
140 unsigned n_var;
141 unsigned n_param;
142 unsigned n_div;
143 unsigned max_var;
144 unsigned n_con;
145 unsigned n_eq;
146 unsigned max_con;
147 struct isl_tab_var *var;
148 struct isl_tab_var *con;
149 int *row_var; /* v >= 0 -> var v; v < 0 -> con ~v */
150 int *col_var; /* v >= 0 -> var v; v < 0 -> con ~v */
151 enum isl_tab_row_sign *row_sign;
153 struct isl_tab_undo bottom;
154 struct isl_tab_undo *top;
156 struct isl_vec *dual;
157 struct isl_basic_map *bmap;
159 unsigned n_sample;
160 unsigned n_outside;
161 int *sample_index;
162 struct isl_mat *samples;
164 int n_zero;
165 int n_unbounded;
166 struct isl_mat *basis;
168 int (*conflict)(int con, void *user);
169 void *conflict_user;
171 unsigned strict_redundant : 1;
172 unsigned need_undo : 1;
173 unsigned preserve : 1;
174 unsigned rational : 1;
175 unsigned empty : 1;
176 unsigned in_undo : 1;
177 unsigned M : 1;
178 unsigned cone : 1;
181 struct isl_tab *isl_tab_alloc(struct isl_ctx *ctx,
182 unsigned n_row, unsigned n_var, unsigned M);
183 void isl_tab_free(struct isl_tab *tab);
185 isl_ctx *isl_tab_get_ctx(struct isl_tab *tab);
187 __isl_give struct isl_tab *isl_tab_from_basic_map(
188 __isl_keep isl_basic_map *bmap, int track);
189 __isl_give struct isl_tab *isl_tab_from_basic_set(
190 __isl_keep isl_basic_set *bset, int track);
191 struct isl_tab *isl_tab_from_recession_cone(struct isl_basic_set *bset,
192 int parametric);
193 int isl_tab_cone_is_bounded(struct isl_tab *tab);
194 struct isl_basic_map *isl_basic_map_update_from_tab(struct isl_basic_map *bmap,
195 struct isl_tab *tab);
196 struct isl_basic_set *isl_basic_set_update_from_tab(struct isl_basic_set *bset,
197 struct isl_tab *tab);
198 int isl_tab_detect_implicit_equalities(struct isl_tab *tab) WARN_UNUSED;
199 __isl_give isl_basic_map *isl_tab_make_equalities_explicit(struct isl_tab *tab,
200 __isl_take isl_basic_map *bmap);
201 int isl_tab_detect_redundant(struct isl_tab *tab) WARN_UNUSED;
202 #define ISL_TAB_SAVE_DUAL (1 << 0)
203 enum isl_lp_result isl_tab_min(struct isl_tab *tab,
204 isl_int *f, isl_int denom, isl_int *opt, isl_int *opt_denom,
205 unsigned flags) WARN_UNUSED;
207 struct isl_tab *isl_tab_extend(struct isl_tab *tab, unsigned n_new) WARN_UNUSED;
208 int isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq) WARN_UNUSED;
209 int isl_tab_add_eq(struct isl_tab *tab, isl_int *eq) WARN_UNUSED;
210 int isl_tab_add_valid_eq(struct isl_tab *tab, isl_int *eq) WARN_UNUSED;
212 int isl_tab_freeze_constraint(struct isl_tab *tab, int con) WARN_UNUSED;
214 int isl_tab_track_bmap(struct isl_tab *tab, __isl_take isl_basic_map *bmap) WARN_UNUSED;
215 int isl_tab_track_bset(struct isl_tab *tab, __isl_take isl_basic_set *bset) WARN_UNUSED;
216 __isl_keep isl_basic_set *isl_tab_peek_bset(struct isl_tab *tab);
218 int isl_tab_is_equality(struct isl_tab *tab, int con);
219 int isl_tab_is_redundant(struct isl_tab *tab, int con);
221 int isl_tab_sample_is_integer(struct isl_tab *tab);
222 struct isl_vec *isl_tab_get_sample_value(struct isl_tab *tab);
224 enum isl_ineq_type {
225 isl_ineq_error = -1,
226 isl_ineq_redundant,
227 isl_ineq_separate,
228 isl_ineq_cut,
229 isl_ineq_adj_eq,
230 isl_ineq_adj_ineq,
233 enum isl_ineq_type isl_tab_ineq_type(struct isl_tab *tab, isl_int *ineq);
235 struct isl_tab_undo *isl_tab_snap(struct isl_tab *tab);
236 int isl_tab_rollback(struct isl_tab *tab, struct isl_tab_undo *snap) WARN_UNUSED;
238 struct isl_tab *isl_tab_relax(struct isl_tab *tab, int con) WARN_UNUSED;
239 int isl_tab_select_facet(struct isl_tab *tab, int con) WARN_UNUSED;
240 int isl_tab_unrestrict(struct isl_tab *tab, int con) WARN_UNUSED;
242 void isl_tab_dump(__isl_keep struct isl_tab *tab);
244 struct isl_map *isl_tab_basic_map_partial_lexopt(
245 struct isl_basic_map *bmap, struct isl_basic_set *dom,
246 struct isl_set **empty, int max);
247 __isl_give isl_pw_multi_aff *isl_basic_map_partial_lexopt_pw_multi_aff(
248 __isl_take isl_basic_map *bmap, __isl_take isl_basic_set *dom,
249 __isl_give isl_set **empty, int max);
251 /* An isl_region represents a sequence of consecutive variables.
252 * pos is the location (starting at 0) of the first variable in the sequence.
254 struct isl_region {
255 int pos;
256 int len;
259 __isl_give isl_vec *isl_tab_basic_set_non_trivial_lexmin(
260 __isl_take isl_basic_set *bset, int n_op, int n_region,
261 struct isl_region *region,
262 int (*conflict)(int con, void *user), void *user);
263 __isl_give isl_vec *isl_tab_basic_set_non_neg_lexmin(
264 __isl_take isl_basic_set *bset);
266 /* private */
268 struct isl_tab_var *isl_tab_var_from_row(struct isl_tab *tab, int i);
269 int isl_tab_mark_redundant(struct isl_tab *tab, int row) WARN_UNUSED;
270 int isl_tab_mark_empty(struct isl_tab *tab) WARN_UNUSED;
271 struct isl_tab *isl_tab_dup(struct isl_tab *tab);
272 struct isl_tab *isl_tab_product(struct isl_tab *tab1, struct isl_tab *tab2);
273 int isl_tab_extend_cons(struct isl_tab *tab, unsigned n_new) WARN_UNUSED;
274 int isl_tab_allocate_con(struct isl_tab *tab) WARN_UNUSED;
275 int isl_tab_extend_vars(struct isl_tab *tab, unsigned n_new) WARN_UNUSED;
276 int isl_tab_allocate_var(struct isl_tab *tab) WARN_UNUSED;
277 int isl_tab_pivot(struct isl_tab *tab, int row, int col) WARN_UNUSED;
278 int isl_tab_add_row(struct isl_tab *tab, isl_int *line) WARN_UNUSED;
279 int isl_tab_row_is_redundant(struct isl_tab *tab, int row);
280 int isl_tab_min_at_most_neg_one(struct isl_tab *tab, struct isl_tab_var *var);
281 int isl_tab_sign_of_max(struct isl_tab *tab, int con);
282 int isl_tab_kill_col(struct isl_tab *tab, int col) WARN_UNUSED;
284 int isl_tab_push(struct isl_tab *tab, enum isl_tab_undo_type type) WARN_UNUSED;
285 int isl_tab_push_var(struct isl_tab *tab,
286 enum isl_tab_undo_type type, struct isl_tab_var *var) WARN_UNUSED;
287 int isl_tab_push_basis(struct isl_tab *tab) WARN_UNUSED;
289 struct isl_tab *isl_tab_init_samples(struct isl_tab *tab) WARN_UNUSED;
290 int isl_tab_add_sample(struct isl_tab *tab,
291 __isl_take isl_vec *sample) WARN_UNUSED;
292 struct isl_tab *isl_tab_drop_sample(struct isl_tab *tab, int s);
293 int isl_tab_save_samples(struct isl_tab *tab) WARN_UNUSED;
295 struct isl_tab *isl_tab_detect_equalities(struct isl_tab *tab,
296 struct isl_tab *tab_cone) WARN_UNUSED;
298 int isl_tab_push_callback(struct isl_tab *tab,
299 struct isl_tab_callback *callback) WARN_UNUSED;
301 int isl_tab_add_div(struct isl_tab *tab, __isl_keep isl_vec *div,
302 int (*add_ineq)(void *user, isl_int *), void *user);
304 #endif