add isl_aff_mod_val

[platform/upstream/isl.git] / isl_equalities.c

diff --git a/isl_equalities.c b/isl_equalities.c
index fa8ee58..9589032 100644 (file)
--- a/isl_equalities.c
+++ b/isl_equalities.c
@@ -1,10 +1,13 @@
 /*
  * Copyright 2008-2009 Katholieke Universiteit Leuven
+ * Copyright 2010      INRIA Saclay
  *
- * Use of this software is governed by the GNU LGPLv2.1 license
+ * 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
+ * and INRIA Saclay - Ile-de-France, Parc Club Orsay Universite,
+ * ZAC des vignes, 4 rue Jacques Monod, 91893 Orsay, France
  */
 
 #include <isl_mat_private.h>
@@ -374,6 +377,59 @@ error:
 
 /* Given a set of equalities
  *
+ *             B(y) + A x = 0                                          (*)
+ *
+ * compute and return an affine transformation T,
+ *
+ *             y = T y'
+ *
+ * that bijectively maps the integer vectors y' to integer
+ * vectors y that satisfy the modulo constraints for some value of x.
+ *
+ * Let [H 0] be the Hermite Normal Form of A, i.e.,
+ *
+ *             A = [H 0] Q
+ *
+ * Then y is a solution of (*) iff
+ *
+ *             H^-1 B(y) (= - [I 0] Q x)
+ *
+ * is an integer vector.  Let d be the common denominator of H^-1.
+ * We impose
+ *
+ *             d H^-1 B(y) = 0 mod d
+ *
+ * and compute the solution using isl_mat_parameter_compression.
+ */
+__isl_give isl_mat *isl_mat_parameter_compression_ext(__isl_take isl_mat *B,
+       __isl_take isl_mat *A)
+{
+       isl_ctx *ctx;
+       isl_vec *d;
+       int n_row, n_col;
+
+       if (!A)
+               return isl_mat_free(B);
+
+       ctx = isl_mat_get_ctx(A);
+       n_row = A->n_row;
+       n_col = A->n_col;
+       A = isl_mat_left_hermite(A, 0, NULL, NULL);
+       A = isl_mat_drop_cols(A, n_row, n_col - n_row);
+       A = isl_mat_lin_to_aff(A);
+       A = isl_mat_right_inverse(A);
+       d = isl_vec_alloc(ctx, n_row);
+       if (A)
+               d = isl_vec_set(d, A->row[0][0]);
+       A = isl_mat_drop_rows(A, 0, 1);
+       A = isl_mat_drop_cols(A, 0, 1);
+       B = isl_mat_product(A, B);
+
+       return isl_mat_parameter_compression(B, d);
+}
+
+/* Given a set of equalities
+ *
  *             M x - c = 0
  *
  * this function computes a unimodular transformation from a lower-dimensional
@@ -413,8 +469,8 @@ error:
  *
  *             x2' = Q2 x
  */
-struct isl_mat *isl_mat_variable_compression(struct isl_mat *B,
-       struct isl_mat **T2)
+__isl_give isl_mat *isl_mat_variable_compression(__isl_take isl_mat *B,
+       __isl_give isl_mat **T2)
 {
        int i;
        struct isl_mat *H = NULL, *C = NULL, *H1, *U = NULL, *U1, *U2, *TC;
@@ -575,7 +631,7 @@ int isl_basic_set_dim_residue_class(struct isl_basic_set *bset,
        if (!bset || !modulo || !residue)
                return -1;
 
-       if (isl_basic_set_fast_dim_is_fixed(bset, pos, residue)) {
+       if (isl_basic_set_plain_dim_is_fixed(bset, pos, residue)) {
                isl_int_set_si(*modulo, 0);
                return 0;
        }
@@ -670,20 +726,15 @@ int isl_set_dim_residue_class(struct isl_set *set,
        isl_int_init(r);
 
        for (i = 1; i < set->n; ++i) {
-               if (isl_basic_set_dim_residue_class(set->p[0], pos, &m, &r) < 0)
+               if (isl_basic_set_dim_residue_class(set->p[i], pos, &m, &r) < 0)
                        goto error;
                isl_int_gcd(*modulo, *modulo, m);
+               isl_int_sub(m, *residue, r);
+               isl_int_gcd(*modulo, *modulo, m);
                if (!isl_int_is_zero(*modulo))
                        isl_int_fdiv_r(*residue, *residue, *modulo);
                if (isl_int_is_one(*modulo))
                        break;
-               if (!isl_int_is_zero(*modulo))
-                       isl_int_fdiv_r(r, r, *modulo);
-               if (isl_int_ne(*residue, r)) {
-                       isl_int_set_si(*modulo, 1);
-                       isl_int_set_si(*residue, 0);
-                       break;
-               }
        }
 
        isl_int_clear(m);