add isl_basic_map_sum

diff --git a/include/isl_map.h b/include/isl_map.h
index 2fa93ea..e874261 100644 (file)
--- a/include/isl_map.h
+++ b/include/isl_map.h
@@ -158,6 +158,9 @@ struct isl_basic_map *isl_basic_map_simplify(struct isl_basic_map *bmap);
 struct isl_basic_map *isl_basic_map_read_from_file(struct isl_ctx *ctx,
                FILE *input, unsigned nparam, unsigned input_format);
 
+struct isl_basic_map *isl_basic_map_sum(
+               struct isl_basic_map *bmap1, struct isl_basic_map *bmap2);
+
 struct isl_map *isl_basic_map_lexmax(
                struct isl_basic_map *bmap, struct isl_basic_set *dom,
                struct isl_set **empty);

diff --git a/isl_map.c b/isl_map.c
index 884f919..9d0c9d1 100644 (file)
--- a/isl_map.c
+++ b/isl_map.c
@@ -1761,6 +1761,65 @@ error:
        return NULL;
 }
 
+/* Given two basic maps A -> f(A) and B -> g(B), construct a basic map
+ * A \cap B -> f(A) + f(B)
+ */
+struct isl_basic_map *isl_basic_map_sum(
+               struct isl_basic_map *bmap1, struct isl_basic_map *bmap2)
+{
+       unsigned n_in, n_out, nparam, total, pos;
+       struct isl_basic_map *bmap = NULL;
+       struct isl_dim_map *dim_map1, *dim_map2;
+       int i;
+
+       if (!bmap1 || !bmap2)
+               goto error;
+
+       isl_assert(bmap1->ctx, isl_dim_equal(bmap1->dim, bmap2->dim),
+               goto error);
+
+       nparam = isl_basic_map_n_param(bmap1);
+       n_in = isl_basic_map_n_in(bmap1);
+       n_out = isl_basic_map_n_out(bmap1);
+
+       total = nparam + n_in + n_out + bmap1->n_div + bmap2->n_div + 2 * n_out;
+       dim_map1 = isl_dim_map_alloc(bmap1->ctx, total);
+       dim_map2 = isl_dim_map_alloc(bmap2->ctx, total);
+       isl_dim_map_dim(dim_map1, bmap1->dim, isl_dim_param, pos = 0);
+       isl_dim_map_dim(dim_map2, bmap2->dim, isl_dim_param, pos);
+       isl_dim_map_dim(dim_map1, bmap1->dim, isl_dim_in, pos += nparam);
+       isl_dim_map_dim(dim_map2, bmap2->dim, isl_dim_in, pos);
+       isl_dim_map_div(dim_map1, bmap1, pos += n_in + n_out);
+       isl_dim_map_div(dim_map2, bmap2, pos += bmap1->n_div);
+       isl_dim_map_dim(dim_map1, bmap1->dim, isl_dim_out, pos += bmap2->n_div);
+       isl_dim_map_dim(dim_map2, bmap2->dim, isl_dim_out, pos += n_out);
+
+       bmap = isl_basic_map_alloc_dim(isl_dim_copy(bmap1->dim),
+                       bmap1->n_div + bmap2->n_div + 2 * n_out,
+                       bmap1->n_eq + bmap2->n_eq + n_out,
+                       bmap1->n_ineq + bmap2->n_ineq);
+       for (i = 0; i < n_out; ++i) {
+               int j = isl_basic_map_alloc_equality(bmap);
+               if (j < 0)
+                       goto error;
+               isl_seq_clr(bmap->eq[j], 1+total);
+               isl_int_set_si(bmap->eq[j][1+nparam+n_in+i], -1);
+               isl_int_set_si(bmap->eq[j][1+pos+i], 1);
+               isl_int_set_si(bmap->eq[j][1+pos-n_out+i], 1);
+       }
+       bmap = add_constraints_dim_map(bmap, bmap1, dim_map1);
+       bmap = add_constraints_dim_map(bmap, bmap2, dim_map2);
+       bmap = add_divs(bmap, 2 * n_out);
+
+       bmap = isl_basic_map_simplify(bmap);
+       return isl_basic_map_finalize(bmap);
+error:
+       isl_basic_map_free(bmap);
+       isl_basic_map_free(bmap1);
+       isl_basic_map_free(bmap2);
+       return NULL;
+}
+
 static struct isl_basic_map *var_equal(struct isl_ctx *ctx,
                struct isl_basic_map *bmap, unsigned pos)
 {