X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=isl_ilp.c;h=e6bc62429a7159c63559fb3c471b41221afe04c2;hb=ca90b151a05f17ccc1c3215ff24dc5d7b9198ff4;hp=67e734f37d4254358333bbd3f54b3a10db22d755;hpb=6437c208a0d25a16fbadd23676d66468caa9e8b2;p=platform%2Fupstream%2Fisl.git

diff --git a/isl_ilp.c b/isl_ilp.c
index 67e734f..e6bc624 100644
--- a/isl_ilp.c
+++ b/isl_ilp.c
@@ -1,8 +1,21 @@
-#include "isl_ilp.h"
-#include "isl_map_private.h"
+/*
+ * 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
+ */
+
+#include <isl_ctx_private.h>
+#include <isl_map_private.h>
+#include <isl/ilp.h>
 #include "isl_sample.h"
-#include "isl_seq.h"
+#include <isl/seq.h>
 #include "isl_equalities.h"
+#include <isl_aff_private.h>
+#include <isl_local_space_private.h>
+#include <isl_mat_private.h>
 
 /* Given a basic set "bset", construct a basic set U such that for
  * each element x in U, the whole unit box positioned at x is inside
@@ -29,7 +42,7 @@ static struct isl_basic_set *unit_box_base_points(struct isl_basic_set *bset)
 	}
 
 	total = isl_basic_set_total_dim(bset);
-	unit_box = isl_basic_set_alloc_dim(isl_basic_set_get_dim(bset),
+	unit_box = isl_basic_set_alloc_space(isl_basic_set_get_space(bset),
 					0, 0, bset->n_ineq);
 
 	for (i = 0; i < bset->n_ineq; ++i) {
@@ -110,16 +123,10 @@ error:
 	return NULL;
 }
 
-/* Find an integer point in "bset" that minimizes f (if any).
- * If sol_p is not NULL then the integer point is returned in *sol_p.
- * The optimal value of f is returned in *opt.
- *
- * The algorithm maintains a currently best solution and an interval [l, u]
- * of values of f for which integer solutions could potentially still be found.
- * The initial value of the best solution so far is any solution.
- * The initial value of l is minimal value of f over the rationals
- * (rounded up to the nearest integer).
- * The initial value of u is the value of f at the current solution minus 1.
+/* Find an integer point in "bset" that minimizes f (in any) such that
+ * the value of f lies inside the interval [l, u].
+ * Return this integer point if it can be found.
+ * Otherwise, return sol.
  *
  * We perform a number of steps until l > u.
  * In each step, we look for an integer point with value in either
@@ -132,14 +139,72 @@ error:
  * If no point can be found, we update l to the upper bound of the interval
  * we checked (u or l+floor(u-l-1/2)) plus 1.
  */
+static struct isl_vec *solve_ilp_search(struct isl_basic_set *bset,
+	isl_int *f, isl_int *opt, struct isl_vec *sol, isl_int l, isl_int u)
+{
+	isl_int tmp;
+	int divide = 1;
+
+	isl_int_init(tmp);
+
+	while (isl_int_le(l, u)) {
+		struct isl_basic_set *slice;
+		struct isl_vec *sample;
+
+		if (!divide)
+			isl_int_set(tmp, u);
+		else {
+			isl_int_sub(tmp, u, l);
+			isl_int_fdiv_q_ui(tmp, tmp, 2);
+			isl_int_add(tmp, tmp, l);
+		}
+		slice = add_bounds(isl_basic_set_copy(bset), f, l, tmp);
+		sample = isl_basic_set_sample_vec(slice);
+		if (!sample) {
+			isl_vec_free(sol);
+			sol = NULL;
+			break;
+		}
+		if (sample->size > 0) {
+			isl_vec_free(sol);
+			sol = sample;
+			isl_seq_inner_product(f, sol->el, sol->size, opt);
+			isl_int_sub_ui(u, *opt, 1);
+			divide = 1;
+		} else {
+			isl_vec_free(sample);
+			if (!divide)
+				break;
+			isl_int_add_ui(l, tmp, 1);
+			divide = 0;
+		}
+	}
+
+	isl_int_clear(tmp);
+
+	return sol;
+}
+
+/* Find an integer point in "bset" that minimizes f (if any).
+ * If sol_p is not NULL then the integer point is returned in *sol_p.
+ * The optimal value of f is returned in *opt.
+ *
+ * The algorithm maintains a currently best solution and an interval [l, u]
+ * of values of f for which integer solutions could potentially still be found.
+ * The initial value of the best solution so far is any solution.
+ * The initial value of l is minimal value of f over the rationals
+ * (rounded up to the nearest integer).
+ * The initial value of u is the value of f at the initial solution minus 1.
+ *
+ * We then call solve_ilp_search to perform a binary search on the interval.
+ */
 static enum isl_lp_result solve_ilp(struct isl_basic_set *bset,
 				      isl_int *f, isl_int *opt,
 				      struct isl_vec **sol_p)
 {
 	enum isl_lp_result res;
-	isl_int l, u, tmp;
+	isl_int l, u;
 	struct isl_vec *sol;
-	int divide = 1;
 
 	res = isl_basic_set_solve_lp(bset, 0, f, bset->ctx->one,
 					opt, NULL, &sol);
@@ -168,50 +233,18 @@ static enum isl_lp_result solve_ilp(struct isl_basic_set *bset,
 
 	isl_int_init(l);
 	isl_int_init(u);
-	isl_int_init(tmp);
 
 	isl_int_set(l, *opt);
 
 	isl_seq_inner_product(f, sol->el, sol->size, opt);
 	isl_int_sub_ui(u, *opt, 1);
 
-	while (isl_int_le(l, u)) {
-		struct isl_basic_set *slice;
-		struct isl_vec *sample;
-
-		if (!divide)
-			isl_int_set(tmp, u);
-		else {
-			isl_int_sub(tmp, u, l);
-			isl_int_fdiv_q_ui(tmp, tmp, 2);
-			isl_int_add(tmp, tmp, l);
-		}
-		slice = add_bounds(isl_basic_set_copy(bset), f, l, tmp);
-		sample = isl_basic_set_sample_vec(slice);
-		if (!sample) {
-			isl_vec_free(sol);
-			sol = NULL;
-			res = isl_lp_error;
-			break;
-		}
-		if (sample->size > 0) {
-			isl_vec_free(sol);
-			sol = sample;
-			isl_seq_inner_product(f, sol->el, sol->size, opt);
-			isl_int_sub_ui(u, *opt, 1);
-			divide = 1;
-		} else {
-			isl_vec_free(sample);
-			if (!divide)
-				break;
-			isl_int_add_ui(l, tmp, 1);
-			divide = 0;
-		}
-	}
+	sol = solve_ilp_search(bset, f, opt, sol, l, u);
+	if (!sol)
+		res = isl_lp_error;
 
 	isl_int_clear(l);
 	isl_int_clear(u);
-	isl_int_clear(tmp);
 
 	if (sol_p)
 		*sol_p = sol;
@@ -230,6 +263,7 @@ static enum isl_lp_result solve_ilp_with_eq(struct isl_basic_set *bset, int max,
 	struct isl_mat *T = NULL;
 	struct isl_vec *v;
 
+	bset = isl_basic_set_copy(bset);
 	dim = isl_basic_set_total_dim(bset);
 	v = isl_vec_alloc(bset->ctx, 1 + dim);
 	if (!v)
@@ -241,12 +275,13 @@ static enum isl_lp_result solve_ilp_with_eq(struct isl_basic_set *bset, int max,
 		goto error;
 	res = isl_basic_set_solve_ilp(bset, max, v->el, opt, sol_p);
 	isl_vec_free(v);
-	if (res == isl_lp_ok && *sol_p) {
+	if (res == isl_lp_ok && sol_p) {
 		*sol_p = isl_mat_vec_product(T, *sol_p);
 		if (!*sol_p)
 			res = isl_lp_error;
 	} else
 		isl_mat_free(T);
+	isl_basic_set_free(bset);
 	return res;
 error:
 	isl_mat_free(T);
@@ -276,6 +311,9 @@ enum isl_lp_result isl_basic_set_solve_ilp(struct isl_basic_set *bset, int max,
 
 	isl_assert(bset->ctx, isl_basic_set_n_param(bset) == 0, goto error);
 
+	if (isl_basic_set_plain_is_empty(bset))
+		return isl_lp_empty;
+
 	if (bset->n_eq)
 		return solve_ilp_with_eq(bset, max, f, opt, sol_p);
 
@@ -296,3 +334,182 @@ error:
 	isl_basic_set_free(bset);
 	return isl_lp_error;
 }
+
+static enum isl_lp_result basic_set_opt(__isl_keep isl_basic_set *bset, int max,
+	__isl_keep isl_aff *obj, isl_int *opt)
+{
+	enum isl_lp_result res;
+
+	if (!obj)
+		return isl_lp_error;
+	bset = isl_basic_set_copy(bset);
+	bset = isl_basic_set_underlying_set(bset);
+	res = isl_basic_set_solve_ilp(bset, max, obj->v->el + 1, opt, NULL);
+	isl_basic_set_free(bset);
+	return res;
+}
+
+static __isl_give isl_mat *extract_divs(__isl_keep isl_basic_set *bset)
+{
+	int i;
+	isl_ctx *ctx = isl_basic_set_get_ctx(bset);
+	isl_mat *div;
+
+	div = isl_mat_alloc(ctx, bset->n_div,
+			    1 + 1 + isl_basic_set_total_dim(bset));
+	if (!div)
+		return NULL;
+
+	for (i = 0; i < bset->n_div; ++i)
+		isl_seq_cpy(div->row[i], bset->div[i], div->n_col);
+
+	return div;
+}
+
+enum isl_lp_result isl_basic_set_opt(__isl_keep isl_basic_set *bset, int max,
+	__isl_keep isl_aff *obj, isl_int *opt)
+{
+	int *exp1 = NULL;
+	int *exp2 = NULL;
+	isl_ctx *ctx;
+	isl_mat *bset_div = NULL;
+	isl_mat *div = NULL;
+	enum isl_lp_result res;
+
+	if (!bset || !obj)
+		return isl_lp_error;
+
+	ctx = isl_aff_get_ctx(obj);
+	if (!isl_space_is_equal(bset->dim, obj->ls->dim))
+		isl_die(ctx, isl_error_invalid,
+			"spaces don't match", return isl_lp_error);
+	if (!isl_int_is_one(obj->v->el[0]))
+		isl_die(ctx, isl_error_unsupported,
+			"expecting integer affine expression",
+			return isl_lp_error);
+
+	if (bset->n_div == 0 && obj->ls->div->n_row == 0)
+		return basic_set_opt(bset, max, obj, opt);
+
+	bset = isl_basic_set_copy(bset);
+	obj = isl_aff_copy(obj);
+
+	bset_div = extract_divs(bset);
+	exp1 = isl_alloc_array(ctx, int, bset_div->n_row);
+	exp2 = isl_alloc_array(ctx, int, obj->ls->div->n_row);
+	if (!bset_div || !exp1 || !exp2)
+		goto error;
+
+	div = isl_merge_divs(bset_div, obj->ls->div, exp1, exp2);
+
+	bset = isl_basic_set_expand_divs(bset, isl_mat_copy(div), exp1);
+	obj = isl_aff_expand_divs(obj, isl_mat_copy(div), exp2);
+
+	res = basic_set_opt(bset, max, obj, opt);
+
+	isl_mat_free(bset_div);
+	isl_mat_free(div);
+	free(exp1);
+	free(exp2);
+	isl_basic_set_free(bset);
+	isl_aff_free(obj);
+
+	return res;
+error:
+	isl_mat_free(div);
+	isl_mat_free(bset_div);
+	free(exp1);
+	free(exp2);
+	isl_basic_set_free(bset);
+	isl_aff_free(obj);
+	return isl_lp_error;
+}
+
+/* Compute the minimum (maximum if max is set) of the integer affine
+ * expression obj over the points in set and put the result in *opt.
+ *
+ * The parameters are assumed to have been aligned.
+ */
+static enum isl_lp_result isl_set_opt_aligned(__isl_keep isl_set *set, int max,
+	__isl_keep isl_aff *obj, isl_int *opt)
+{
+	int i;
+	enum isl_lp_result res;
+	int empty = 1;
+	isl_int opt_i;
+
+	if (!set || !obj)
+		return isl_lp_error;
+	if (set->n == 0)
+		return isl_lp_empty;
+
+	res = isl_basic_set_opt(set->p[0], max, obj, opt);
+	if (res == isl_lp_error || res == isl_lp_unbounded)
+		return res;
+	if (set->n == 1)
+		return res;
+	if (res == isl_lp_ok)
+		empty = 0;
+
+	isl_int_init(opt_i);
+	for (i = 1; i < set->n; ++i) {
+		res = isl_basic_set_opt(set->p[i], max, obj, &opt_i);
+		if (res == isl_lp_error || res == isl_lp_unbounded) {
+			isl_int_clear(opt_i);
+			return res;
+		}
+		if (res == isl_lp_ok)
+			empty = 0;
+		if (isl_int_gt(opt_i, *opt))
+			isl_int_set(*opt, opt_i);
+	}
+	isl_int_clear(opt_i);
+
+	return empty ? isl_lp_empty : isl_lp_ok;
+}
+
+/* Compute the minimum (maximum if max is set) of the integer affine
+ * expression obj over the points in set and put the result in *opt.
+ */
+enum isl_lp_result isl_set_opt(__isl_keep isl_set *set, int max,
+	__isl_keep isl_aff *obj, isl_int *opt)
+{
+	enum isl_lp_result res;
+
+	if (!set || !obj)
+		return isl_lp_error;
+
+	if (isl_space_match(set->dim, isl_dim_param,
+			    obj->ls->dim, isl_dim_param))
+		return isl_set_opt_aligned(set, max, obj, opt);
+
+	set = isl_set_copy(set);
+	obj = isl_aff_copy(obj);
+	set = isl_set_align_params(set, isl_aff_get_domain_space(obj));
+	obj = isl_aff_align_params(obj, isl_set_get_space(set));
+
+	res = isl_set_opt_aligned(set, max, obj, opt);
+
+	isl_set_free(set);
+	isl_aff_free(obj);
+
+	return res;
+}
+
+enum isl_lp_result isl_basic_set_max(__isl_keep isl_basic_set *bset,
+	__isl_keep isl_aff *obj, isl_int *opt)
+{
+	return isl_basic_set_opt(bset, 1, obj, opt);
+}
+
+enum isl_lp_result isl_set_max(__isl_keep isl_set *set,
+	__isl_keep isl_aff *obj, isl_int *opt)
+{
+	return isl_set_opt(set, 1, obj, opt);
+}
+
+enum isl_lp_result isl_set_min(__isl_keep isl_set *set,
+	__isl_keep isl_aff *obj, isl_int *opt)
+{
+	return isl_set_opt(set, 0, obj, opt);
+}