+}
+
+static jit_bool_t
+_block_update_set(jit_state_t *_jit,
+ jit_block_t *block, jit_block_t *target)
+{
+ jit_regset_t regmask;
+
+ jit_regset_ior(®mask, &block->reglive, &target->reglive);
+ jit_regset_and(®mask, ®mask, &block->regmask);
+ if (jit_regset_set_p(®mask)) {
+ jit_regset_ior(&block->reglive, &block->reglive, ®mask);
+ jit_regset_and(®mask, &block->reglive, &block->regmask);
+ jit_regset_com(®mask, ®mask);
+ jit_regset_and(&block->regmask, &block->regmask, ®mask);
+ block->again = 1;
+ return (1);
+ }
+ return (0);
+}
+
+static void
+_propagate_backward(jit_state_t *_jit, jit_block_t *block)
+{
+ jit_block_t *prev;
+ jit_word_t offset;
+
+ for (offset = block->label->v.w - 1;
+ offset >= 0; --offset) {
+ prev = _jitc->blocks.ptr + offset;
+ if (!block_update_set(prev, block) ||
+ !(prev->label->flag & jit_flag_head))
+ break;
+ }
+}
+
+static jit_bool_t
+_check_block_again(jit_state_t *_jit)
+{
+ jit_int32_t todo;
+ jit_word_t offset;
+ jit_node_t *node, *label;
+ jit_block_t *block, *target;
+
+ todo = 0;
+ for (offset = 0; offset < _jitc->blocks.offset; offset++) {
+ block = _jitc->blocks.ptr + offset;
+ if (block->again) {
+ todo = 1;
+ break;
+ }
+ }
+ /* If no block changed state */
+ if (!todo)
+ return (0);