-extern void sbitmap_union_of_diff (sbitmap, sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_union_of_diff_cg (sbitmap, sbitmap, sbitmap, sbitmap);
-extern void sbitmap_difference (sbitmap, sbitmap, sbitmap);
-extern void sbitmap_not (sbitmap, sbitmap);
-extern void sbitmap_a_or_b_and_c (sbitmap, sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_a_or_b_and_c_cg (sbitmap, sbitmap, sbitmap, sbitmap);
-extern void sbitmap_a_and_b_or_c (sbitmap, sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_a_and_b_or_c_cg (sbitmap, sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_any_common_bits (sbitmap, sbitmap);
-extern void sbitmap_a_and_b (sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_a_and_b_cg (sbitmap, sbitmap, sbitmap);
-extern void sbitmap_a_or_b (sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_a_or_b_cg (sbitmap, sbitmap, sbitmap);
-extern void sbitmap_a_xor_b (sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_a_xor_b_cg (sbitmap, sbitmap, sbitmap);
-extern bool sbitmap_a_subset_b_p (sbitmap, sbitmap);
-
-extern int sbitmap_first_set_bit (sbitmap);
-extern int sbitmap_last_set_bit (sbitmap);
+extern void sbitmap_union_of_diff (sbitmap, const_sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_union_of_diff_cg (sbitmap, const_sbitmap, const_sbitmap, const_sbitmap);
+extern void sbitmap_difference (sbitmap, const_sbitmap, const_sbitmap);
+extern void sbitmap_not (sbitmap, const_sbitmap);
+extern void sbitmap_a_or_b_and_c (sbitmap, const_sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_a_or_b_and_c_cg (sbitmap, const_sbitmap, const_sbitmap, const_sbitmap);
+extern void sbitmap_a_and_b_or_c (sbitmap, const_sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_a_and_b_or_c_cg (sbitmap, const_sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_any_common_bits (const_sbitmap, const_sbitmap);
+extern void sbitmap_a_and_b (sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_a_and_b_cg (sbitmap, const_sbitmap, const_sbitmap);
+extern void sbitmap_a_or_b (sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_a_or_b_cg (sbitmap, const_sbitmap, const_sbitmap);
+extern void sbitmap_a_xor_b (sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_a_xor_b_cg (sbitmap, const_sbitmap, const_sbitmap);
+extern bool sbitmap_a_subset_b_p (const_sbitmap, const_sbitmap);
+
+extern int sbitmap_first_set_bit (const_sbitmap);
+extern int sbitmap_last_set_bit (const_sbitmap);