Use %lu and a cast to output bb->index.
@@ -4182,7 +4182,7 @@ static void combine (MIR_context_t ctx) {
for (bb_t bb = DLIST_HEAD (bb_t, curr_cfg->bbs); bb != NULL; bb = DLIST_NEXT (bb_t, bb)) {
do {
#if MIR_GEN_DEBUG
- if (debug_file != NULL) fprintf (debug_file, "Processing bb%d\n", bb->index);
+ if (debug_file != NULL) fprintf (debug_file, "Processing bb%lu\n", (unsigned long) bb->index);
#endif
block_change_p = FALSE;
curr_bb_hreg_ref_age++;
