isl_bound: plug memory leak

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

diff --git a/isl_equalities.c b/isl_equalities.c
index 1702620..0e1faa5 100644 (file)
--- a/isl_equalities.c
+++ b/isl_equalities.c
@@ -1,3 +1,12 @@
+/*
+ * Copyright 2008-2009 Katholieke Universiteit Leuven
+ *
+ * Use of this software is governed by the GNU LGPLv2.1 license
+ *
+ * Written by Sven Verdoolaege, K.U.Leuven, Departement
+ * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
+ */
+
 #include "isl_mat.h"
 #include "isl_seq.h"
 #include "isl_map_private.h"
@@ -240,7 +249,7 @@ error:
  * then we divide this row of A by the common factor, unless gcd(A_i) = 0.
  * In the later case, we simply drop the row (in both A and d).
  *
- * If there are no rows left in A, the G is the identity matrix. Otherwise,
+ * If there are no rows left in A, then G is the identity matrix. Otherwise,
  * for each row i, we now determine the lattice of integer vectors
  * that satisfies this row.  Let U_i be the unimodular extension of the
  * row A_i.  This unimodular extension exists because gcd(A_i) = 1.
@@ -363,12 +372,12 @@ error:
  *
  *             M x - c = 0
  *
- * this function computes unimodular transformation from a lower-dimensional
+ * this function computes a unimodular transformation from a lower-dimensional
  * space to the original space that bijectively maps the integer points x'
  * in the lower-dimensional space to the integer points x in the original
  * space that satisfy the equalities.
  *
- * The input is given as a matrix B = [ -c M ] and the out is a
+ * The input is given as a matrix B = [ -c M ] and the output is a
  * matrix that maps [1 x'] to [1 x].
  * If T2 is not NULL, then *T2 is set to a matrix mapping [1 x] to [1 x'].
  *
@@ -391,7 +400,7 @@ error:
  *
  * If any of the c' is non-integer, then the original set has no
  * integer solutions (since the x' are a unimodular transformation
- * of the x).
+ * of the x) and a zero-column matrix is returned.
  * Otherwise, the transformation is given by
  *
  *             x = U1 H1^{-1} c + U2 x2'
@@ -619,3 +628,67 @@ error:
        isl_mat_free(U);
        return -1;
 }
+
+/* Check if dimension dim belongs to a residue class
+ *             i_dim \equiv r mod m
+ * with m != 1 and if so return m in *modulo and r in *residue.
+ * As a special case, when i_dim has a fixed value v, then
+ * *modulo is set to 0 and *residue to v.
+ *
+ * If i_dim does not belong to such a residue class, then *modulo
+ * is set to 1 and *residue is set to 0.
+ */
+int isl_set_dim_residue_class(struct isl_set *set,
+       int pos, isl_int *modulo, isl_int *residue)
+{
+       isl_int m;
+       isl_int r;
+       int i;
+
+       if (!set || !modulo || !residue)
+               return -1;
+
+       if (set->n == 0) {
+               isl_int_set_si(*modulo, 0);
+               isl_int_set_si(*residue, 0);
+               return 0;
+       }
+
+       if (isl_basic_set_dim_residue_class(set->p[0], pos, modulo, residue)<0)
+               return -1;
+
+       if (set->n == 1)
+               return 0;
+
+       if (isl_int_is_one(*modulo))
+               return 0;
+
+       isl_int_init(m);
+       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)
+                       goto error;
+               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);
+       isl_int_clear(r);
+
+       return 0;
+error:
+       isl_int_clear(m);
+       isl_int_clear(r);
+       return -1;
+}