isl_tab_detect_implicit_equalities: also detect manifest equalities
[platform/upstream/isl.git] / isl_fold.c
index c6ef285..f04b4d4 100644 (file)
 
 #include <isl_polynomial_private.h>
 #include <isl_point_private.h>
-#include <isl_dim_private.h>
+#include <isl_dim.h>
 #include <isl_map_private.h>
+#include <isl_lp.h>
+#include <isl_seq.h>
+
+static __isl_give isl_qpolynomial_fold *qpolynomial_fold_alloc(
+       enum isl_fold type, __isl_take isl_dim *dim, int n)
+{
+       isl_qpolynomial_fold *fold;
+
+       if (!dim)
+               goto error;
+
+       isl_assert(dim->ctx, n >= 0, goto error);
+       fold = isl_calloc(dim->ctx, struct isl_qpolynomial_fold,
+                       sizeof(struct isl_qpolynomial_fold) +
+                       (n - 1) * sizeof(struct isl_qpolynomial *));
+       if (!fold)
+               goto error;
+
+       fold->ref = 1;
+       fold->size = n;
+       fold->n = 0;
+       fold->type = type;
+       fold->dim = dim;
+
+       return fold;
+error:
+       isl_dim_free(dim);
+       return NULL;
+}
 
 int isl_qpolynomial_fold_involves_dims(__isl_keep isl_qpolynomial_fold *fold,
        enum isl_dim_type type, unsigned first, unsigned n)
@@ -63,46 +92,260 @@ error:
        return NULL;
 }
 
-#undef PW
-#define PW isl_pw_qpolynomial_fold
-#undef EL
-#define EL isl_qpolynomial_fold
-#undef IS_ZERO
-#define IS_ZERO is_empty
-#undef FIELD
-#define FIELD fold
-#undef ADD
-#define ADD fold
+static int isl_qpolynomial_cst_sign(__isl_keep isl_qpolynomial *qp)
+{
+       struct isl_upoly_cst *cst;
 
-#include <isl_pw_templ.c>
+       cst = isl_upoly_as_cst(qp->upoly);
+       if (!cst)
+               return 0;
 
-static __isl_give isl_qpolynomial_fold *qpolynomial_fold_alloc(
-       enum isl_fold type, __isl_take isl_dim *dim, int n)
+       return isl_int_sgn(cst->n) < 0 ? -1 : 1;
+}
+
+static int isl_qpolynomial_aff_sign(__isl_keep isl_set *set,
+       __isl_keep isl_qpolynomial *qp)
 {
-       isl_qpolynomial_fold *fold;
+       enum isl_lp_result res;
+       isl_vec *aff;
+       isl_int opt;
+       int sgn = 0;
 
-       if (!dim)
+       aff = isl_qpolynomial_extract_affine(qp);
+       if (!aff)
+               return 0;
+
+       isl_int_init(opt);
+
+       res = isl_set_solve_lp(set, 0, aff->el + 1, aff->el[0],
+                               &opt, NULL, NULL);
+       if (res == isl_lp_error)
+               goto done;
+       if (res == isl_lp_empty ||
+           (res == isl_lp_ok && !isl_int_is_neg(opt))) {
+               sgn = 1;
+               goto done;
+       }
+
+       res = isl_set_solve_lp(set, 1, aff->el + 1, aff->el[0],
+                               &opt, NULL, NULL);
+       if (res == isl_lp_ok && !isl_int_is_pos(opt))
+               sgn = -1;
+
+done:
+       isl_int_clear(opt);
+       isl_vec_free(aff);
+       return sgn;
+}
+
+/* Determine, if possible, the sign of the quasipolynomial "qp" on
+ * the domain "set".
+ *
+ * If qp is a constant, then the problem is trivial.
+ * If qp is linear, then we check if the minimum of the corresponding
+ * affine constraint is non-negative or if the maximum is non-positive.
+ *
+ * Otherwise, we check if the outermost variable "v" has a lower bound "l"
+ * in "set".  If so, we write qp(v,v') as
+ *
+ *     q(v,v') * (v - l) + r(v')
+ *
+ * if q(v,v') and r(v') have the same known sign, then the original
+ * quasipolynomial has the same sign as well.
+ *
+ * Return
+ *     -1 if qp <= 0
+ *      1 if qp >= 0
+ *      0 if unknown
+ */
+static int isl_qpolynomial_sign(__isl_keep isl_set *set,
+       __isl_keep isl_qpolynomial *qp)
+{
+       int d;
+       int i;
+       int is;
+       struct isl_upoly_rec *rec;
+       isl_vec *v;
+       isl_int l;
+       enum isl_lp_result res;
+       int sgn = 0;
+
+       is = isl_qpolynomial_is_cst(qp, NULL, NULL);
+       if (is < 0)
+               return 0;
+       if (is)
+               return isl_qpolynomial_cst_sign(qp);
+
+       is = isl_qpolynomial_is_affine(qp);
+       if (is < 0)
+               return 0;
+       if (is)
+               return isl_qpolynomial_aff_sign(set, qp);
+
+       if (qp->div->n_row > 0)
+               return 0;
+
+       rec = isl_upoly_as_rec(qp->upoly);
+       if (!rec)
+               return 0;
+
+       d = isl_dim_total(qp->dim);
+       v = isl_vec_alloc(set->ctx, 2 + d);
+       if (!v)
+               return 0;
+
+       isl_seq_clr(v->el + 1, 1 + d);
+       isl_int_set_si(v->el[0], 1);
+       isl_int_set_si(v->el[2 + qp->upoly->var], 1);
+
+       isl_int_init(l);
+
+       res = isl_set_solve_lp(set, 0, v->el + 1, v->el[0], &l, NULL, NULL);
+       if (res == isl_lp_ok) {
+               isl_qpolynomial *min;
+               isl_qpolynomial *base;
+               isl_qpolynomial *r, *q;
+               isl_qpolynomial *t;
+
+               min = isl_qpolynomial_cst(isl_dim_copy(qp->dim), l);
+               base = isl_qpolynomial_pow(isl_dim_copy(qp->dim),
+                                               qp->upoly->var, 1);
+
+               r = isl_qpolynomial_alloc(isl_dim_copy(qp->dim), 0,
+                                         isl_upoly_copy(rec->p[rec->n - 1]));
+               q = isl_qpolynomial_copy(r);
+
+               for (i = rec->n - 2; i >= 0; --i) {
+                       r = isl_qpolynomial_mul(r, isl_qpolynomial_copy(min));
+                       t = isl_qpolynomial_alloc(isl_dim_copy(qp->dim), 0,
+                                                 isl_upoly_copy(rec->p[i]));
+                       r = isl_qpolynomial_add(r, t);
+                       if (i == 0)
+                               break;
+                       q = isl_qpolynomial_mul(q, isl_qpolynomial_copy(base));
+                       q = isl_qpolynomial_add(q, isl_qpolynomial_copy(r));
+               }
+
+               if (isl_qpolynomial_is_zero(q))
+                       sgn = isl_qpolynomial_sign(set, r);
+               else if (isl_qpolynomial_is_zero(r))
+                       sgn = isl_qpolynomial_sign(set, q);
+               else {
+                       int sgn_q, sgn_r;
+                       sgn_r = isl_qpolynomial_sign(set, r);
+                       sgn_q = isl_qpolynomial_sign(set, q);
+                       if (sgn_r == sgn_q)
+                               sgn = sgn_r;
+               }
+
+               isl_qpolynomial_free(min);
+               isl_qpolynomial_free(base);
+               isl_qpolynomial_free(q);
+               isl_qpolynomial_free(r);
+       }
+
+       isl_int_clear(l);
+
+       isl_vec_free(v);
+
+       return sgn;
+}
+
+__isl_give isl_qpolynomial_fold *isl_qpolynomial_fold_fold_on_domain(
+       __isl_keep isl_set *set,
+       __isl_take isl_qpolynomial_fold *fold1,
+       __isl_take isl_qpolynomial_fold *fold2)
+{
+       int i, j;
+       int n1;
+       struct isl_qpolynomial_fold *res = NULL;
+       int better;
+
+       if (!fold1 || !fold2)
                goto error;
 
-       isl_assert(dim->ctx, n >= 0, goto error);
-       fold = isl_alloc(dim->ctx, struct isl_qpolynomial_fold,
-                       sizeof(struct isl_qpolynomial_fold) +
-                       (n - 1) * sizeof(struct isl_qpolynomial *));
-       if (!fold)
+       isl_assert(fold1->dim->ctx, fold1->type == fold2->type, goto error);
+       isl_assert(fold1->dim->ctx, isl_dim_equal(fold1->dim, fold2->dim),
+                       goto error);
+
+       better = fold1->type == isl_fold_max ? -1 : 1;
+
+       if (isl_qpolynomial_fold_is_empty(fold1)) {
+               isl_qpolynomial_fold_free(fold1);
+               return fold2;
+       }
+
+       if (isl_qpolynomial_fold_is_empty(fold2)) {
+               isl_qpolynomial_fold_free(fold2);
+               return fold1;
+       }
+
+       res = qpolynomial_fold_alloc(fold1->type, isl_dim_copy(fold1->dim),
+                                       fold1->n + fold2->n);
+       if (!res)
                goto error;
 
-       fold->ref = 1;
-       fold->size = n;
-       fold->n = 0;
-       fold->type = type;
-       fold->dim = dim;
+       for (i = 0; i < fold1->n; ++i) {
+               res->qp[res->n] = isl_qpolynomial_copy(fold1->qp[i]);
+               if (!res->qp[res->n])
+                       goto error;
+               res->n++;
+       }
+       n1 = res->n;
 
-       return fold;
+       for (i = 0; i < fold2->n; ++i) {
+               for (j = n1 - 1; j >= 0; --j) {
+                       isl_qpolynomial *d;
+                       int sgn;
+                       d = isl_qpolynomial_sub(
+                               isl_qpolynomial_copy(res->qp[j]),
+                               isl_qpolynomial_copy(fold2->qp[i]));
+                       sgn = isl_qpolynomial_sign(set, d);
+                       isl_qpolynomial_free(d);
+                       if (sgn == 0)
+                               continue;
+                       if (sgn != better)
+                               break;
+                       isl_qpolynomial_free(res->qp[j]);
+                       if (j != n1 - 1)
+                               res->qp[j] = res->qp[n1 - 1];
+                       n1--;
+                       if (n1 != res->n - 1)
+                               res->qp[n1] = res->qp[res->n - 1];
+                       res->n--;
+               }
+               if (j >= 0)
+                       continue;
+               res->qp[res->n] = isl_qpolynomial_copy(fold2->qp[i]);
+               if (!res->qp[res->n])
+                       goto error;
+               res->n++;
+       }
+
+       isl_qpolynomial_fold_free(fold1);
+       isl_qpolynomial_fold_free(fold2);
+
+       return res;
 error:
-       isl_dim_free(dim);
+       isl_qpolynomial_fold_free(res);
+       isl_qpolynomial_fold_free(fold1);
+       isl_qpolynomial_fold_free(fold2);
        return NULL;
 }
 
+#undef PW
+#define PW isl_pw_qpolynomial_fold
+#undef EL
+#define EL isl_qpolynomial_fold
+#undef IS_ZERO
+#define IS_ZERO is_empty
+#undef FIELD
+#define FIELD fold
+#undef ADD
+#define ADD(d,e1,e2)   isl_qpolynomial_fold_fold_on_domain(d,e1,e2) 
+
+#include <isl_pw_templ.c>
+
 __isl_give isl_qpolynomial_fold *isl_qpolynomial_fold_empty(enum isl_fold type,
        __isl_take isl_dim *dim)
 {
@@ -154,6 +397,7 @@ __isl_give isl_qpolynomial_fold *isl_qpolynomial_fold_dup(
        if (!dup)
                return NULL;
        
+       dup->n = fold->n;
        for (i = 0; i < fold->n; ++i) {
                dup->qp[i] = isl_qpolynomial_copy(fold->qp[i]);
                if (!dup->qp[i])
@@ -336,3 +580,273 @@ error:
        isl_point_free(pnt);
        return NULL;
 }
+
+size_t isl_pw_qpolynomial_fold_size(__isl_keep isl_pw_qpolynomial_fold *pwf)
+{
+       int i;
+       size_t n = 0;
+
+       for (i = 0; i < pwf->n; ++i)
+               n += pwf->p[i].fold->n;
+
+       return n;
+}
+
+__isl_give isl_qpolynomial *isl_qpolynomial_fold_opt_on_domain(
+       __isl_take isl_qpolynomial_fold *fold, __isl_take isl_set *set, int max)
+{
+       int i;
+       isl_qpolynomial *opt;
+
+       if (!set || !fold)
+               goto error;
+
+       if (fold->n == 0) {
+               isl_dim *dim = isl_dim_copy(fold->dim);
+               isl_set_free(set);
+               isl_qpolynomial_fold_free(fold);
+               return isl_qpolynomial_zero(dim);
+       }
+
+       opt = isl_qpolynomial_opt_on_domain(isl_qpolynomial_copy(fold->qp[0]),
+                                               isl_set_copy(set), max);
+       for (i = 1; i < fold->n; ++i) {
+               isl_qpolynomial *opt_i;
+               opt_i = isl_qpolynomial_opt_on_domain(
+                               isl_qpolynomial_copy(fold->qp[i]),
+                               isl_set_copy(set), max);
+               if (max)
+                       opt = isl_qpolynomial_max_cst(opt, opt_i);
+               else
+                       opt = isl_qpolynomial_min_cst(opt, opt_i);
+       }
+
+       isl_set_free(set);
+       isl_qpolynomial_fold_free(fold);
+
+       return opt;
+error:
+       isl_set_free(set);
+       isl_qpolynomial_fold_free(fold);
+       return NULL;
+}
+
+/* Check whether for each quasi-polynomial in "fold2" there is
+ * a quasi-polynomial in "fold1" that dominates it on "set".
+ */
+static int qpolynomial_fold_covers_on_domain(__isl_keep isl_set *set,
+       __isl_keep isl_qpolynomial_fold *fold1,
+       __isl_keep isl_qpolynomial_fold *fold2)
+{
+       int i, j;
+       int covers;
+
+       if (!set || !fold1 || !fold2)
+               return -1;
+
+       covers = fold1->type == isl_fold_max ? 1 : -1;
+
+       for (i = 0; i < fold2->n; ++i) {
+               for (j = 0; j < fold1->n; ++j) {
+                       isl_qpolynomial *d;
+                       int sgn;
+
+                       d = isl_qpolynomial_sub(
+                               isl_qpolynomial_copy(fold1->qp[j]),
+                               isl_qpolynomial_copy(fold2->qp[i]));
+                       sgn = isl_qpolynomial_sign(set, d);
+                       isl_qpolynomial_free(d);
+                       if (sgn == covers)
+                               break;
+               }
+               if (j >= fold1->n)
+                       return 0;
+       }
+
+       return 1;
+}
+
+/* Check whether "pwf1" dominated "pwf2", i.e., the domain of "pwf1" contains
+ * that of "pwf2" and on each cell, the corresponding fold from pwf1 dominates
+ * that of pwf2.
+ */
+int isl_pw_qpolynomial_fold_covers(__isl_keep isl_pw_qpolynomial_fold *pwf1,
+       __isl_keep isl_pw_qpolynomial_fold *pwf2)
+{
+       int i, j;
+       isl_set *dom1, *dom2;
+       int is_subset;
+
+       if (!pwf1 || !pwf2)
+               return -1;
+
+       if (pwf2->n == 0)
+               return 1;
+       if (pwf1->n == 0)
+               return 0;
+
+       dom1 = isl_pw_qpolynomial_fold_domain(isl_pw_qpolynomial_fold_copy(pwf1));
+       dom2 = isl_pw_qpolynomial_fold_domain(isl_pw_qpolynomial_fold_copy(pwf2));
+       is_subset = isl_set_is_subset(dom2, dom1);
+       isl_set_free(dom1);
+       isl_set_free(dom2);
+
+       if (is_subset < 0 || !is_subset)
+               return is_subset;
+
+       for (i = 0; i < pwf2->n; ++i) {
+               for (j = 0; j < pwf1->n; ++j) {
+                       int is_empty;
+                       isl_set *common;
+                       int covers;
+
+                       common = isl_set_intersect(isl_set_copy(pwf1->p[j].set),
+                                                  isl_set_copy(pwf2->p[i].set));
+                       is_empty = isl_set_is_empty(common);
+                       if (is_empty < 0 || is_empty) {
+                               isl_set_free(common);
+                               if (is_empty < 0)
+                                       return -1;
+                               continue;
+                       }
+                       covers = qpolynomial_fold_covers_on_domain(common,
+                                       pwf1->p[j].fold, pwf2->p[i].fold);
+                       isl_set_free(common);
+                       if (covers < 0 || !covers)
+                               return covers;
+               }
+       }
+
+       return 1;
+}
+
+__isl_give isl_qpolynomial_fold *isl_qpolynomial_fold_morph(
+       __isl_take isl_qpolynomial_fold *fold, __isl_take isl_morph *morph)
+{
+       int i;
+       isl_ctx *ctx;
+
+       if (!fold || !morph)
+               goto error;
+
+       ctx = fold->dim->ctx;
+       isl_assert(ctx, isl_dim_equal(fold->dim, morph->dom->dim), goto error);
+
+       fold = isl_qpolynomial_fold_cow(fold);
+       if (!fold)
+               goto error;
+
+       isl_dim_free(fold->dim);
+       fold->dim = isl_dim_copy(morph->ran->dim);
+       if (!fold->dim)
+               goto error;
+
+       for (i = 0; i < fold->n; ++i) {
+               fold->qp[i] = isl_qpolynomial_morph(fold->qp[i],
+                                               isl_morph_copy(morph));
+               if (!fold->qp[i])
+                       goto error;
+       }
+
+       isl_morph_free(morph);
+
+       return fold;
+error:
+       isl_qpolynomial_fold_free(fold);
+       isl_morph_free(morph);
+       return NULL;
+}
+
+enum isl_fold isl_qpolynomial_fold_get_type(__isl_keep isl_qpolynomial_fold *fold)
+{
+       if (!fold)
+               return isl_fold_list;
+       return fold->type;
+}
+
+__isl_give isl_qpolynomial_fold *isl_qpolynomial_fold_lift(
+       __isl_take isl_qpolynomial_fold *fold, __isl_take isl_dim *dim)
+{
+       int i;
+       isl_ctx *ctx;
+
+       if (!fold || !dim)
+               goto error;
+
+       if (isl_dim_equal(fold->dim, dim)) {
+               isl_dim_free(dim);
+               return fold;
+       }
+
+       fold = isl_qpolynomial_fold_cow(fold);
+       if (!fold)
+               goto error;
+
+       isl_dim_free(fold->dim);
+       fold->dim = isl_dim_copy(dim);
+       if (!fold->dim)
+               goto error;
+
+       for (i = 0; i < fold->n; ++i) {
+               fold->qp[i] = isl_qpolynomial_lift(fold->qp[i],
+                                               isl_dim_copy(dim));
+               if (!fold->qp[i])
+                       goto error;
+       }
+
+       isl_dim_free(dim);
+
+       return fold;
+error:
+       isl_qpolynomial_fold_free(fold);
+       isl_dim_free(dim);
+       return NULL;
+}
+
+int isl_qpolynomial_fold_foreach_qpolynomial(
+       __isl_keep isl_qpolynomial_fold *fold,
+       int (*fn)(__isl_take isl_qpolynomial *qp, void *user), void *user)
+{
+       int i;
+
+       if (!fold)
+               return -1;
+
+       for (i = 0; i < fold->n; ++i)
+               if (fn(isl_qpolynomial_copy(fold->qp[i]), user) < 0)
+                       return -1;
+
+       return 0;
+}
+
+__isl_give isl_qpolynomial_fold *isl_qpolynomial_fold_move_dims(
+       __isl_take isl_qpolynomial_fold *fold,
+       enum isl_dim_type dst_type, unsigned dst_pos,
+       enum isl_dim_type src_type, unsigned src_pos, unsigned n)
+{
+       int i;
+
+       if (n == 0)
+               return fold;
+
+       fold = isl_qpolynomial_fold_cow(fold);
+       if (!fold)
+               return NULL;
+
+       fold->dim = isl_dim_move(fold->dim, dst_type, dst_pos,
+                                               src_type, src_pos, n);
+       if (!fold->dim)
+               goto error;
+
+       for (i = 0; i < fold->n; ++i) {
+               fold->qp[i] = isl_qpolynomial_move_dims(fold->qp[i],
+                               dst_type, dst_pos, src_type, src_pos, n);
+               if (!fold->qp[i])
+                       goto error;
+       }
+
+       return fold;
+error:
+       isl_qpolynomial_fold_free(fold);
+       return NULL;
+}