isl_output.c: print_disjunct: use names from space argument
[isl.git] / basis_reduction_tab.c
blobcd97548508a02e7243cb819b47343a3318523fa5
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 #include <assert.h>
11 #include <isl_map_private.h>
12 #include <isl_seq.h>
13 #include "isl_tab.h"
14 #include <isl_int.h>
15 #include <isl_config.h>
17 struct tab_lp {
18 struct isl_ctx *ctx;
19 struct isl_vec *row;
20 struct isl_tab *tab;
21 struct isl_tab_undo **stack;
22 isl_int *obj;
23 isl_int opt;
24 isl_int opt_denom;
25 isl_int tmp;
26 isl_int tmp2;
27 int neq;
28 unsigned dim;
29 /* number of constraints in initial product tableau */
30 int con_offset;
31 /* objective function has fixed or no integer value */
32 int is_fixed;
35 #ifdef USE_GMP_FOR_MP
36 #define GBR_type mpq_t
37 #define GBR_init(v) mpq_init(v)
38 #define GBR_clear(v) mpq_clear(v)
39 #define GBR_set(a,b) mpq_set(a,b)
40 #define GBR_set_ui(a,b) mpq_set_ui(a,b,1)
41 #define GBR_mul(a,b,c) mpq_mul(a,b,c)
42 #define GBR_lt(a,b) (mpq_cmp(a,b) < 0)
43 #define GBR_is_zero(a) (mpq_sgn(a) == 0)
44 #define GBR_numref(a) mpq_numref(a)
45 #define GBR_denref(a) mpq_denref(a)
46 #define GBR_floor(a,b) mpz_fdiv_q(a,GBR_numref(b),GBR_denref(b))
47 #define GBR_ceil(a,b) mpz_cdiv_q(a,GBR_numref(b),GBR_denref(b))
48 #endif /* USE_GMP_FOR_MP */
50 #ifdef USE_IMATH_FOR_MP
51 #include <imrat.h>
53 #define GBR_type mp_rat
54 #define GBR_init(v) v = mp_rat_alloc()
55 #define GBR_clear(v) mp_rat_free(v)
56 #define GBR_set(a,b) mp_rat_copy(b,a)
57 #define GBR_set_ui(a,b) mp_rat_set_uvalue(a,b,1)
58 #define GBR_mul(a,b,c) mp_rat_mul(b,c,a)
59 #define GBR_lt(a,b) (mp_rat_compare(a,b) < 0)
60 #define GBR_is_zero(a) (mp_rat_compare_zero(a) == 0)
61 #define GBR_numref(a) mp_rat_numer_ref(a)
62 #define GBR_denref(a) mp_rat_denom_ref(a)
63 #define GBR_floor(a,b) impz_fdiv_q(a,GBR_numref(b),GBR_denref(b))
64 #define GBR_ceil(a,b) impz_cdiv_q(a,GBR_numref(b),GBR_denref(b))
65 #endif /* USE_IMATH_FOR_MP */
67 static struct tab_lp *init_lp(struct isl_tab *tab);
68 static void set_lp_obj(struct tab_lp *lp, isl_int *row, int dim);
69 static int solve_lp(struct tab_lp *lp);
70 static void get_obj_val(struct tab_lp* lp, GBR_type *F);
71 static void delete_lp(struct tab_lp *lp);
72 static int add_lp_row(struct tab_lp *lp, isl_int *row, int dim);
73 static void get_alpha(struct tab_lp* lp, int row, GBR_type *alpha);
74 static int del_lp_row(struct tab_lp *lp) WARN_UNUSED;
75 static int cut_lp_to_hyperplane(struct tab_lp *lp, isl_int *row);
77 #define GBR_LP struct tab_lp
78 #define GBR_lp_init(P) init_lp(P)
79 #define GBR_lp_set_obj(lp, obj, dim) set_lp_obj(lp, obj, dim)
80 #define GBR_lp_solve(lp) solve_lp(lp)
81 #define GBR_lp_get_obj_val(lp, F) get_obj_val(lp, F)
82 #define GBR_lp_delete(lp) delete_lp(lp)
83 #define GBR_lp_next_row(lp) lp->neq
84 #define GBR_lp_add_row(lp, row, dim) add_lp_row(lp, row, dim)
85 #define GBR_lp_get_alpha(lp, row, alpha) get_alpha(lp, row, alpha)
86 #define GBR_lp_del_row(lp) del_lp_row(lp)
87 #define GBR_lp_is_fixed(lp) (lp)->is_fixed
88 #define GBR_lp_cut(lp, obj) cut_lp_to_hyperplane(lp, obj)
89 #include "basis_reduction_templ.c"
91 /* Set up a tableau for the Cartesian product of bset with itself.
92 * This could be optimized by first setting up a tableau for bset
93 * and then performing the Cartesian product on the tableau.
95 static struct isl_tab *gbr_tab(struct isl_tab *tab, struct isl_vec *row)
97 unsigned dim;
98 struct isl_tab *prod;
100 if (!tab || !row)
101 return NULL;
103 dim = tab->n_var;
104 prod = isl_tab_product(tab, tab);
105 if (isl_tab_extend_cons(prod, 3 * dim + 1) < 0) {
106 isl_tab_free(prod);
107 return NULL;
109 return prod;
112 static struct tab_lp *init_lp(struct isl_tab *tab)
114 struct tab_lp *lp = NULL;
116 if (!tab)
117 return NULL;
119 lp = isl_calloc_type(tab->mat->ctx, struct tab_lp);
120 if (!lp)
121 return NULL;
123 isl_int_init(lp->opt);
124 isl_int_init(lp->opt_denom);
125 isl_int_init(lp->tmp);
126 isl_int_init(lp->tmp2);
128 lp->dim = tab->n_var;
130 lp->ctx = tab->mat->ctx;
131 isl_ctx_ref(lp->ctx);
133 lp->stack = isl_alloc_array(lp->ctx, struct isl_tab_undo *, lp->dim);
135 lp->row = isl_vec_alloc(lp->ctx, 1 + 2 * lp->dim);
136 if (!lp->row)
137 goto error;
138 lp->tab = gbr_tab(tab, lp->row);
139 if (!lp->tab)
140 goto error;
141 lp->con_offset = lp->tab->n_con;
142 lp->obj = NULL;
143 lp->neq = 0;
145 return lp;
146 error:
147 delete_lp(lp);
148 return NULL;
151 static void set_lp_obj(struct tab_lp *lp, isl_int *row, int dim)
153 lp->obj = row;
156 static int solve_lp(struct tab_lp *lp)
158 enum isl_lp_result res;
159 unsigned flags = 0;
161 lp->is_fixed = 0;
163 isl_int_set_si(lp->row->el[0], 0);
164 isl_seq_cpy(lp->row->el + 1, lp->obj, lp->dim);
165 isl_seq_neg(lp->row->el + 1 + lp->dim, lp->obj, lp->dim);
166 if (lp->neq)
167 flags = ISL_TAB_SAVE_DUAL;
168 res = isl_tab_min(lp->tab, lp->row->el, lp->ctx->one,
169 &lp->opt, &lp->opt_denom, flags);
170 isl_int_mul_ui(lp->opt_denom, lp->opt_denom, 2);
171 if (isl_int_abs_lt(lp->opt, lp->opt_denom)) {
172 struct isl_vec *sample = isl_tab_get_sample_value(lp->tab);
173 if (!sample)
174 return -1;
175 isl_seq_inner_product(lp->obj, sample->el + 1, lp->dim, &lp->tmp);
176 isl_seq_inner_product(lp->obj, sample->el + 1 + lp->dim, lp->dim, &lp->tmp2);
177 isl_int_cdiv_q(lp->tmp, lp->tmp, sample->el[0]);
178 isl_int_fdiv_q(lp->tmp2, lp->tmp2, sample->el[0]);
179 if (isl_int_ge(lp->tmp, lp->tmp2))
180 lp->is_fixed = 1;
181 isl_vec_free(sample);
183 isl_int_divexact_ui(lp->opt_denom, lp->opt_denom, 2);
184 if (res < 0)
185 return -1;
186 if (res != isl_lp_ok)
187 isl_die(lp->ctx, isl_error_internal,
188 "unexpected missing (bounded) solution", return -1);
189 return 0;
192 /* The current objective function has a fixed (or no) integer value.
193 * Cut the tableau to the hyperplane that fixes this value in
194 * both halves of the tableau.
195 * Return 1 if the resulting tableau is empty.
197 static int cut_lp_to_hyperplane(struct tab_lp *lp, isl_int *row)
199 enum isl_lp_result res;
201 isl_int_set_si(lp->row->el[0], 0);
202 isl_seq_cpy(lp->row->el + 1, row, lp->dim);
203 isl_seq_clr(lp->row->el + 1 + lp->dim, lp->dim);
204 res = isl_tab_min(lp->tab, lp->row->el, lp->ctx->one,
205 &lp->tmp, NULL, 0);
206 if (res != isl_lp_ok)
207 return -1;
209 isl_int_neg(lp->row->el[0], lp->tmp);
210 if (isl_tab_add_eq(lp->tab, lp->row->el) < 0)
211 return -1;
213 isl_seq_cpy(lp->row->el + 1 + lp->dim, row, lp->dim);
214 isl_seq_clr(lp->row->el + 1, lp->dim);
215 if (isl_tab_add_eq(lp->tab, lp->row->el) < 0)
216 return -1;
218 lp->con_offset += 2;
220 return lp->tab->empty;
223 static void get_obj_val(struct tab_lp* lp, GBR_type *F)
225 isl_int_neg(GBR_numref(*F), lp->opt);
226 isl_int_set(GBR_denref(*F), lp->opt_denom);
229 static void delete_lp(struct tab_lp *lp)
231 if (!lp)
232 return;
234 isl_int_clear(lp->opt);
235 isl_int_clear(lp->opt_denom);
236 isl_int_clear(lp->tmp);
237 isl_int_clear(lp->tmp2);
238 isl_vec_free(lp->row);
239 free(lp->stack);
240 isl_tab_free(lp->tab);
241 isl_ctx_deref(lp->ctx);
242 free(lp);
245 static int add_lp_row(struct tab_lp *lp, isl_int *row, int dim)
247 lp->stack[lp->neq] = isl_tab_snap(lp->tab);
249 isl_int_set_si(lp->row->el[0], 0);
250 isl_seq_cpy(lp->row->el + 1, row, lp->dim);
251 isl_seq_neg(lp->row->el + 1 + lp->dim, row, lp->dim);
253 if (isl_tab_add_valid_eq(lp->tab, lp->row->el) < 0)
254 return -1;
256 return lp->neq++;
259 static void get_alpha(struct tab_lp* lp, int row, GBR_type *alpha)
261 row += lp->con_offset;
262 isl_int_neg(GBR_numref(*alpha), lp->tab->dual->el[1 + row]);
263 isl_int_set(GBR_denref(*alpha), lp->tab->dual->el[0]);
266 static int del_lp_row(struct tab_lp *lp)
268 lp->neq--;
269 return isl_tab_rollback(lp->tab, lp->stack[lp->neq]);