add isl_constraint_involves_dims

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

diff --git a/doc/user.pod b/doc/user.pod
index 95adf2b..d8f1be4 100644 (file)
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -1077,6 +1077,9 @@ the following functions.
        void isl_constraint_get_coefficient(
                __isl_keep isl_constraint *constraint,
                enum isl_dim_type type, int pos, isl_int *v);
+       int isl_constraint_involves_dims(
+               __isl_keep isl_constraint *constraint,
+               enum isl_dim_type type, unsigned first, unsigned n);
 
 The explicit representations of the existentially quantified
 variables can be inspected using the following functions.

diff --git a/include/isl/constraint.h b/include/isl/constraint.h
index 9230e39..974c37f 100644 (file)
--- a/include/isl/constraint.h
+++ b/include/isl/constraint.h
@@ -77,6 +77,9 @@ __isl_give isl_dim *isl_constraint_get_dim(
 int isl_constraint_dim(struct isl_constraint *constraint,
        enum isl_dim_type type);
 
+int isl_constraint_involves_dims(__isl_keep isl_constraint *constraint,
+       enum isl_dim_type type, unsigned first, unsigned n);
+
 const char *isl_constraint_get_dim_name(__isl_keep isl_constraint *constraint,
        enum isl_dim_type type, unsigned pos);
 void isl_constraint_get_constant(__isl_keep isl_constraint *constraint,

diff --git a/isl_constraint.c b/isl_constraint.c
index bcf39ee..446fb95 100644 (file)
--- a/isl_constraint.c
+++ b/isl_constraint.c
@@ -326,6 +326,24 @@ int isl_constraint_dim(struct isl_constraint *constraint,
        return n(constraint, type);
 }
 
+int isl_constraint_involves_dims(__isl_keep isl_constraint *constraint,
+       enum isl_dim_type type, unsigned first, unsigned n)
+{
+       if (!constraint)
+               return -1;
+
+       if (first + n > isl_basic_set_dim(constraint->bmap, type))
+               isl_die(constraint->ctx, isl_error_invalid,
+                       "index out of bounds", return -1);
+
+       first += isl_basic_map_offset(constraint->bmap, type);
+
+       if (isl_seq_first_non_zero(constraint->line[0] + first, n) >= 0)
+               return 1;
+
+       return 0;
+}
+
 const char *isl_constraint_get_dim_name(__isl_keep isl_constraint *constraint,
        enum isl_dim_type type, unsigned pos)
 {