add isl_basic_set_transform_dims

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/isl_map_private.h b/isl_map_private.h
index bcc924f..03fd911 100644 (file)
--- a/isl_map_private.h
+++ b/isl_map_private.h
@@ -269,6 +269,10 @@ struct isl_basic_set *isl_basic_set_preimage(struct isl_basic_set *bset,
        struct isl_mat *mat);
 struct isl_set *isl_set_preimage(struct isl_set *set, struct isl_mat *mat);
 
+__isl_give isl_basic_set *isl_basic_set_transform_dims(
+       __isl_take isl_basic_set *bset, enum isl_dim_type type, unsigned first,
+       __isl_take isl_mat *trans);
+
 isl_int *isl_set_wrap_facet(__isl_keep isl_set *set,
        isl_int *facet, isl_int *ridge);
 

diff --git a/isl_mat.c b/isl_mat.c
index 0f053a5..7a00734 100644 (file)
--- a/isl_mat.c
+++ b/isl_mat.c
@@ -1125,6 +1125,73 @@ error:
        return NULL;
 }
 
+/* Replace the variables x starting at pos in the rows q
+ * by x' with x = M x' with M the matrix mat.
+ * That is, replace the corresponding coefficients c by c M.
+ */
+static int transform(isl_ctx *ctx, isl_int **q, unsigned n,
+       unsigned pos, __isl_take isl_mat *mat)
+{
+       int i;
+       isl_mat *t;
+
+       t = isl_mat_sub_alloc6(ctx, q, 0, n, pos, mat->n_row);
+       t = isl_mat_product(t, mat);
+       if (!t)
+               return -1;
+       for (i = 0; i < n; ++i)
+               isl_seq_swp_or_cpy(q[i] + pos, t->row[i], t->n_col);
+       isl_mat_free(t);
+       return 0;
+}
+
+/* Replace the variables x of type "type" starting at "first" in "bset"
+ * by x' with x = M x' with M the matrix trans.
+ * That is, replace the corresponding coefficients c by c M.
+ *
+ * The transformation matrix should be a square matrix.
+ */
+__isl_give isl_basic_set *isl_basic_set_transform_dims(
+       __isl_take isl_basic_set *bset, enum isl_dim_type type, unsigned first,
+       __isl_take isl_mat *trans)
+{
+       isl_ctx *ctx;
+       unsigned pos;
+
+       bset = isl_basic_set_cow(bset);
+       if (!bset || !trans)
+               goto error;
+
+       ctx = isl_basic_set_get_ctx(bset);
+       if (trans->n_row != trans->n_col)
+               isl_die(trans->ctx, isl_error_invalid,
+                       "expecting square transformation matrix", goto error);
+       if (first + trans->n_row > isl_basic_set_dim(bset, type))
+               isl_die(trans->ctx, isl_error_invalid,
+                       "oversized transformation matrix", goto error);
+
+       pos = isl_basic_set_offset(bset, type) + first;
+
+       if (transform(ctx, bset->eq, bset->n_eq, pos, isl_mat_copy(trans)) < 0)
+               goto error;
+       if (transform(ctx, bset->ineq, bset->n_ineq, pos,
+                     isl_mat_copy(trans)) < 0)
+               goto error;
+       if (transform(ctx, bset->div, bset->n_div, 1 + pos,
+                     isl_mat_copy(trans)) < 0)
+               goto error;
+
+       ISL_F_CLR(bset, ISL_BASIC_SET_NORMALIZED);
+       ISL_F_CLR(bset, ISL_BASIC_SET_NORMALIZED_DIVS);
+
+       isl_mat_free(trans);
+       return bset;
+error:
+       isl_mat_free(trans);
+       isl_basic_set_free(bset);
+       return NULL;
+}
+
 void isl_mat_dump(struct isl_mat *mat, FILE *out, int indent)
 {
        int i, j;