add isl_multi_aff_zero

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

diff --git a/doc/user.pod b/doc/user.pod
index 219c7ec..21eea0b 100644 (file)
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -3209,13 +3209,17 @@ following function.
                __isl_take isl_space *space,
                __isl_take isl_aff_list *list);
 
-An empty piecewise multiple quasi affine expression (one with no cells) or
+An empty piecewise multiple quasi affine expression (one with no cells),
+the zero piecewise multiple quasi affine expression (with value zero
+for each output dimension) or
 a piecewise multiple quasi affine expression with a single cell can
 be created using the following functions.
 
        #include <isl/aff.h>
        __isl_give isl_pw_multi_aff *isl_pw_multi_aff_empty(
                __isl_take isl_space *space);
+       __isl_give isl_multi_aff *isl_multi_aff_zero(
+               __isl_take isl_space *space);
        __isl_give isl_pw_multi_aff *isl_pw_multi_aff_alloc(
                __isl_take isl_set *set,
                __isl_take isl_multi_aff *maff);

diff --git a/include/isl/aff.h b/include/isl/aff.h
index 226c854..7f142dc 100644 (file)
--- a/include/isl/aff.h
+++ b/include/isl/aff.h
@@ -239,6 +239,8 @@ __isl_give isl_set *isl_pw_aff_list_ge_set(__isl_take isl_pw_aff_list *list1,
 __isl_give isl_set *isl_pw_aff_list_gt_set(__isl_take isl_pw_aff_list *list1,
        __isl_take isl_pw_aff_list *list2);
 
+__isl_give isl_multi_aff *isl_multi_aff_zero(__isl_take isl_space *space);
+
 isl_ctx *isl_multi_aff_get_ctx(__isl_keep isl_multi_aff *maff);
 __isl_give isl_space *isl_multi_aff_get_space(__isl_keep isl_multi_aff *maff);
 __isl_give isl_multi_aff *isl_multi_aff_set_tuple_id(

diff --git a/isl_aff.c b/isl_aff.c
index becf73b..8ddd78c 100644 (file)
--- a/isl_aff.c
+++ b/isl_aff.c
@@ -2080,6 +2080,40 @@ __isl_give isl_pw_aff *isl_pw_aff_list_max(__isl_take isl_pw_aff_list *list)
 
 #include <isl_multi_templ.c>
 
+/* Construct an isl_multi_aff in the given space with value zero in
+ * each of the output dimensions.
+ */
+__isl_give isl_multi_aff *isl_multi_aff_zero(__isl_take isl_space *space)
+{
+       int n;
+       isl_multi_aff *ma;
+
+       if (!space)
+               return NULL;
+
+       n = isl_space_dim(space , isl_dim_out);
+       ma = isl_multi_aff_alloc(isl_space_copy(space));
+
+       if (!n)
+               isl_space_free(space);
+       else {
+               int i;
+               isl_local_space *ls;
+               isl_aff *aff;
+
+               space = isl_space_domain(space);
+               ls = isl_local_space_from_space(space);
+               aff = isl_aff_zero_on_domain(ls);
+
+               for (i = 0; i < n; ++i)
+                       ma = isl_multi_aff_set_aff(ma, i, isl_aff_copy(aff));
+
+               isl_aff_free(aff);
+       }
+
+       return ma;
+}
+
 __isl_give isl_multi_aff *isl_multi_aff_add(__isl_take isl_multi_aff *maff1,
        __isl_take isl_multi_aff *maff2)
 {