/* * Copyright 2008-2009 Katholieke Universiteit Leuven * * 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 */ #ifndef ISL_TAB_H #define ISL_TAB_H #include #include #include #include #include struct isl_tab_var { int index; unsigned is_row : 1; unsigned is_nonneg : 1; unsigned is_zero : 1; unsigned is_redundant : 1; unsigned marked : 1; unsigned frozen : 1; unsigned negated : 1; }; enum isl_tab_undo_type { isl_tab_undo_bottom, isl_tab_undo_empty, isl_tab_undo_nonneg, isl_tab_undo_redundant, isl_tab_undo_freeze, isl_tab_undo_zero, isl_tab_undo_allocate, isl_tab_undo_relax, isl_tab_undo_unrestrict, isl_tab_undo_bmap_ineq, isl_tab_undo_bmap_eq, isl_tab_undo_bmap_div, isl_tab_undo_saved_basis, isl_tab_undo_drop_sample, isl_tab_undo_saved_samples, isl_tab_undo_callback, }; struct isl_tab_callback { int (*run)(struct isl_tab_callback *cb); }; union isl_tab_undo_val { int var_index; int *col_var; int n; struct isl_tab_callback *callback; }; struct isl_tab_undo { enum isl_tab_undo_type type; union isl_tab_undo_val u; struct isl_tab_undo *next; }; /* The tableau maintains equality relations. * Each column and each row is associated to a variable or a constraint. * The "value" of an inequality constraint is the value of the corresponding * slack variable. * The "row_var" and "col_var" arrays map column and row indices * to indices in the "var" and "con" arrays. The elements of these * arrays maintain extra information about the variables and the constraints. * Each row expresses the corresponding row variable as an affine expression * of the column variables. * The first two columns in the matrix contain the common denominator of * the row and the numerator of the constant term. * If "M" is set, then the third column represents the "big parameter". * The third (M = 0) or fourth (M = 1) column * in the matrix is called column 0 with respect to the col_var array. * The sample value of the tableau is the value that assigns zero * to all the column variables and the constant term of each affine * expression to the corresponding row variable. * The operations on the tableau maintain the property that the sample * value satisfies the non-negativity constraints (usually on the slack * variables). * * The big parameter represents an arbitrarily big (and divisible) * positive number. If present, then the sign of a row is determined * lexicographically, with the sign of the big parameter coefficient * considered first. The big parameter is only used while * solving PILP problems. * * The first n_dead column variables have their values fixed to zero. * The corresponding tab_vars are flagged "is_zero". * Some of the rows that have have zero coefficients in all but * the dead columns are also flagged "is_zero". * * The first n_redundant rows correspond to inequality constraints * that are always satisfied for any value satisfying the non-redundant * rows. The corresponding tab_vars are flagged "is_redundant". * A row variable that is flagged "is_zero" is also flagged "is_redundant" * since the constraint has been reduced to 0 = 0 and is therefore always * satisfied. * * There are "n_var" variables in total. The first "n_param" of these * are called parameters and the last "n_div" of these are called divs. * The basic tableau operations makes no distinction between different * kinds of variables. These special variables are only used while * solving PILP problems. * * Dead columns and redundant rows are detected on the fly. * However, the basic operations do not ensure that all dead columns * or all redundant rows are detected. * isl_tab_detect_implicit_equalities and isl_tab_detect_redundant can be used * to perform and exhaustive search for dead columns and redundant rows. * * The samples matrix contains "n_sample" integer points that have at some * point been elements satisfying the tableau. The first "n_outside" * of them no longer satisfy the tableau. They are kept because they * can be reinstated during rollback when the constraint that cut them * out is removed. These samples are only maintained for the context * tableau while solving PILP problems. * * If "preserve" is set, then we want to keep all constraints in the * tableau, even if they turn out to be redundant. */ enum isl_tab_row_sign { isl_tab_row_unknown = 0, isl_tab_row_pos, isl_tab_row_neg, isl_tab_row_any, }; struct isl_tab { struct isl_mat *mat; unsigned n_row; unsigned n_col; unsigned n_dead; unsigned n_redundant; unsigned n_var; unsigned n_param; unsigned n_div; unsigned max_var; unsigned n_con; unsigned n_eq; unsigned max_con; struct isl_tab_var *var; struct isl_tab_var *con; int *row_var; /* v >= 0 -> var v; v < 0 -> con ~v */ int *col_var; /* v >= 0 -> var v; v < 0 -> con ~v */ enum isl_tab_row_sign *row_sign; struct isl_tab_undo bottom; struct isl_tab_undo *top; struct isl_vec *dual; struct isl_basic_map *bmap; unsigned n_sample; unsigned n_outside; int *sample_index; struct isl_mat *samples; int n_zero; int n_unbounded; struct isl_mat *basis; int (*conflict)(int con, void *user); void *conflict_user; unsigned strict_redundant : 1; unsigned need_undo : 1; unsigned preserve : 1; unsigned rational : 1; unsigned empty : 1; unsigned in_undo : 1; unsigned M : 1; unsigned cone : 1; }; struct isl_tab *isl_tab_alloc(struct isl_ctx *ctx, unsigned n_row, unsigned n_var, unsigned M); void isl_tab_free(struct isl_tab *tab); isl_ctx *isl_tab_get_ctx(struct isl_tab *tab); __isl_give struct isl_tab *isl_tab_from_basic_map( __isl_keep isl_basic_map *bmap, int track); __isl_give struct isl_tab *isl_tab_from_basic_set( __isl_keep isl_basic_set *bset, int track); struct isl_tab *isl_tab_from_recession_cone(struct isl_basic_set *bset, int parametric); int isl_tab_cone_is_bounded(struct isl_tab *tab); struct isl_basic_map *isl_basic_map_update_from_tab(struct isl_basic_map *bmap, struct isl_tab *tab); struct isl_basic_set *isl_basic_set_update_from_tab(struct isl_basic_set *bset, struct isl_tab *tab); int isl_tab_detect_implicit_equalities(struct isl_tab *tab) WARN_UNUSED; __isl_give isl_basic_map *isl_tab_make_equalities_explicit(struct isl_tab *tab, __isl_take isl_basic_map *bmap); int isl_tab_detect_redundant(struct isl_tab *tab) WARN_UNUSED; #define ISL_TAB_SAVE_DUAL (1 << 0) enum isl_lp_result isl_tab_min(struct isl_tab *tab, isl_int *f, isl_int denom, isl_int *opt, isl_int *opt_denom, unsigned flags) WARN_UNUSED; int isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq) WARN_UNUSED; int isl_tab_add_eq(struct isl_tab *tab, isl_int *eq) WARN_UNUSED; int isl_tab_add_valid_eq(struct isl_tab *tab, isl_int *eq) WARN_UNUSED; int isl_tab_freeze_constraint(struct isl_tab *tab, int con) WARN_UNUSED; int isl_tab_track_bmap(struct isl_tab *tab, __isl_take isl_basic_map *bmap) WARN_UNUSED; int isl_tab_track_bset(struct isl_tab *tab, __isl_take isl_basic_set *bset) WARN_UNUSED; __isl_keep isl_basic_set *isl_tab_peek_bset(struct isl_tab *tab); int isl_tab_is_equality(struct isl_tab *tab, int con); int isl_tab_is_redundant(struct isl_tab *tab, int con); int isl_tab_sample_is_integer(struct isl_tab *tab); struct isl_vec *isl_tab_get_sample_value(struct isl_tab *tab); enum isl_ineq_type { isl_ineq_error = -1, isl_ineq_redundant, isl_ineq_separate, isl_ineq_cut, isl_ineq_adj_eq, isl_ineq_adj_ineq, }; enum isl_ineq_type isl_tab_ineq_type(struct isl_tab *tab, isl_int *ineq); struct isl_tab_undo *isl_tab_snap(struct isl_tab *tab); int isl_tab_rollback(struct isl_tab *tab, struct isl_tab_undo *snap) WARN_UNUSED; struct isl_tab *isl_tab_relax(struct isl_tab *tab, int con) WARN_UNUSED; int isl_tab_select_facet(struct isl_tab *tab, int con) WARN_UNUSED; int isl_tab_unrestrict(struct isl_tab *tab, int con) WARN_UNUSED; void isl_tab_dump(__isl_keep struct isl_tab *tab); struct isl_map *isl_tab_basic_map_partial_lexopt( struct isl_basic_map *bmap, struct isl_basic_set *dom, struct isl_set **empty, int max); __isl_give isl_pw_multi_aff *isl_basic_map_partial_lexopt_pw_multi_aff( __isl_take isl_basic_map *bmap, __isl_take isl_basic_set *dom, __isl_give isl_set **empty, int max); /* An isl_region represents a sequence of consecutive variables. * pos is the location (starting at 0) of the first variable in the sequence. */ struct isl_region { int pos; int len; }; __isl_give isl_vec *isl_tab_basic_set_non_trivial_lexmin( __isl_take isl_basic_set *bset, int n_op, int n_region, struct isl_region *region, int (*conflict)(int con, void *user), void *user); __isl_give isl_vec *isl_tab_basic_set_non_neg_lexmin( __isl_take isl_basic_set *bset); /* private */ struct isl_tab_var *isl_tab_var_from_row(struct isl_tab *tab, int i); int isl_tab_mark_redundant(struct isl_tab *tab, int row) WARN_UNUSED; int isl_tab_mark_empty(struct isl_tab *tab) WARN_UNUSED; struct isl_tab *isl_tab_dup(struct isl_tab *tab); struct isl_tab *isl_tab_product(struct isl_tab *tab1, struct isl_tab *tab2); int isl_tab_extend_cons(struct isl_tab *tab, unsigned n_new) WARN_UNUSED; int isl_tab_allocate_con(struct isl_tab *tab) WARN_UNUSED; int isl_tab_extend_vars(struct isl_tab *tab, unsigned n_new) WARN_UNUSED; int isl_tab_allocate_var(struct isl_tab *tab) WARN_UNUSED; int isl_tab_pivot(struct isl_tab *tab, int row, int col) WARN_UNUSED; int isl_tab_add_row(struct isl_tab *tab, isl_int *line) WARN_UNUSED; int isl_tab_row_is_redundant(struct isl_tab *tab, int row); int isl_tab_min_at_most_neg_one(struct isl_tab *tab, struct isl_tab_var *var); int isl_tab_sign_of_max(struct isl_tab *tab, int con); int isl_tab_kill_col(struct isl_tab *tab, int col) WARN_UNUSED; int isl_tab_push(struct isl_tab *tab, enum isl_tab_undo_type type) WARN_UNUSED; int isl_tab_push_var(struct isl_tab *tab, enum isl_tab_undo_type type, struct isl_tab_var *var) WARN_UNUSED; int isl_tab_push_basis(struct isl_tab *tab) WARN_UNUSED; struct isl_tab *isl_tab_init_samples(struct isl_tab *tab) WARN_UNUSED; int isl_tab_add_sample(struct isl_tab *tab, __isl_take isl_vec *sample) WARN_UNUSED; struct isl_tab *isl_tab_drop_sample(struct isl_tab *tab, int s); int isl_tab_save_samples(struct isl_tab *tab) WARN_UNUSED; struct isl_tab *isl_tab_detect_equalities(struct isl_tab *tab, struct isl_tab *tab_cone) WARN_UNUSED; int isl_tab_push_callback(struct isl_tab *tab, struct isl_tab_callback *callback) WARN_UNUSED; int isl_tab_add_div(struct isl_tab *tab, __isl_keep isl_vec *div, int (*add_ineq)(void *user, isl_int *), void *user); #endif