+/* Call this with -1 to start checking from 0. Returns -1 at the end. */
+int bitbag_next_bit(struct bitbag *bb, int after)
+{
+ uint32 bits, mask;
+ int i, ndx = after + 1;
+ int slot = ndx / BB_PER_SLOT_BITS;
+ ndx %= BB_PER_SLOT_BITS;
+
+ mask = (1u << (ndx % 32)) - 1;
+ for (i = ndx / 32; slot < bb->slot_cnt; slot++, i = mask = 0) {
+ if (!bb->bits[slot])
+ continue;
+ for ( ; i < BB_PER_SLOT_INTS; i++, mask = 0) {
+ if (!(bits = bb->bits[slot][i] & ~mask))
+ continue;
+ /* The xor magic figures out the lowest enabled bit in
+ * bits, and the switch quickly computes log2(bit). */
+ switch (bits ^ (bits & (bits-1))) {
+#define LOG2(n) case 1u << n: return slot*BB_PER_SLOT_BITS + i*32 + n
+ LOG2(0); LOG2(1); LOG2(2); LOG2(3);
+ LOG2(4); LOG2(5); LOG2(6); LOG2(7);
+ LOG2(8); LOG2(9); LOG2(10); LOG2(11);
+ LOG2(12); LOG2(13); LOG2(14); LOG2(15);
+ LOG2(16); LOG2(17); LOG2(18); LOG2(19);
+ LOG2(20); LOG2(21); LOG2(22); LOG2(23);
+ LOG2(24); LOG2(25); LOG2(26); LOG2(27);
+ LOG2(28); LOG2(29); LOG2(30); LOG2(31);
+ }
+ return -1; /* impossible... */
+ }
+ }
+
+ return -1;
+}
+
+void *expand_item_list(item_list *lp, size_t item_size,
+ const char *desc, int incr)
+{
+ /* First time through, 0 <= 0, so list is expanded. */
+ if (lp->malloced <= lp->count) {
+ void *new_ptr;
+ size_t new_size = lp->malloced;
+ if (incr < 0)
+ new_size += -incr; /* increase slowly */
+ else if (new_size < (size_t)incr)
+ new_size += incr;
+ else
+ new_size *= 2;
+ if (new_size < lp->malloced)
+ overflow_exit("expand_item_list");
+ /* Using _realloc_array() lets us pass the size, not a type. */
+ new_ptr = _realloc_array(lp->items, item_size, new_size);
+ if (verbose >= 4) {
+ rprintf(FINFO, "[%s] expand %s to %.0f bytes, did%s move\n",
+ who_am_i(), desc, (double)new_size * item_size,
+ new_ptr == lp->items ? " not" : "");