isl_basic_set_solve_ilp: handle obviously empty sets

diff --git a/isl_ilp.c b/isl_ilp.c
index 15110c1..0d57d6e 100644 (file)
--- a/isl_ilp.c
+++ b/isl_ilp.c
@@ -298,6 +298,9 @@ enum isl_lp_result isl_basic_set_solve_ilp(struct isl_basic_set *bset, int max,
 
        isl_assert(bset->ctx, isl_basic_set_n_param(bset) == 0, goto error);
 
+       if (isl_basic_set_fast_is_empty(bset))
+               return isl_lp_empty;
+
        if (bset->n_eq)
                return solve_ilp_with_eq(bset, max, f, opt, sol_p);