BlockBegin* LoopFinder::insert_caching_block(LoopList* loops, BlockBegin* from, BlockBegin* to) {
if (from->next() && from->next()->as_CachingChange() != NULL &&
from->end()->default_sux() == to) {
// we already have a caching change block
// check that the precision flags are the same
#ifdef ASSERT
CachingChange* cc = from->next()->as_CachingChange();
assert(cc->pred_block()->is_set(BlockBegin::single_precision_flag) == from->is_set(BlockBegin::single_precision_flag), "consistency check");
assert(cc->sux_block()->is_set(BlockBegin::single_precision_flag) == to->is_set(BlockBegin::single_precision_flag), "consistency check");
#endif
return NULL;
} else {
// insert a caching change block, making it close to any single successor
int bci = -1;
BlockLoopInfo* bli = get_block_info(to);
if (bli->nof_preds() == 1) {
bci = to->bci();
} else {
bci = from->end()->bci();
}
BlockBegin* cc = new_block(to->scope(), bci);
BlockEnd* e = new Goto(to, false);
cc->set_end(e);
cc->set_next(new CachingChange(from, to), bci)->set_next(e, bci);
if (PrintLoops && Verbose) {
tty->print_cr("Added caching block B%d (dest B%d)", cc->block_id(), to->block_id());
}
BlockEnd* from_end = from->end();
from_end->substitute_sux(to, cc);
cc->join(from_end->state());
assert(cc->state() != NULL, "illegal operation");
ValueStack* end_state = cc->state()->copy();
cc->end()->set_state(end_state);
to->join(end_state);
assert(cc->end()->state() != NULL, "should have state");
loops->update_loops(from, to, cc);
return cc;
}
}
