1605 
1606 //------------------------------print_statistics-------------------------------
1607 #ifndef PRODUCT
1608 void PhasePeephole::print_statistics() {
1609   tty->print_cr("Peephole: peephole rules applied: %d",  _total_peepholes);
1610 }
1611 #endif
1612 
1613 
1614 //=============================================================================
1615 //------------------------------set_req_X--------------------------------------
1616 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) {
1617   assert( is_not_dead(n), "can not use dead node");
1618   assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" );
1619   Node *old = in(i);
1620   set_req(i, n);
1621 
1622   // old goes dead?
1623   if( old ) {
1624     switch (old->outcnt()) {
1625     case 0:      // Kill all his inputs, and recursively kill other dead nodes.


1626       if (!old->is_top())
1627         igvn->remove_dead_node( old );
1628       break;
1629     case 1:
1630       if( old->is_Store() || old->has_special_unique_user() )
1631         igvn->add_users_to_worklist( old );
1632       break;
1633     case 2:
1634       if( old->is_Store() )
1635         igvn->add_users_to_worklist( old );
1636       if( old->Opcode() == Op_Region )
1637         igvn->_worklist.push(old);
1638       break;
1639     case 3:
1640       if( old->Opcode() == Op_Region ) {
1641         igvn->_worklist.push(old);
1642         igvn->add_users_to_worklist( old );
1643       }
1644       break;
1645     default:
1646       break;
1647     }

1605 
1606 //------------------------------print_statistics-------------------------------
1607 #ifndef PRODUCT
1608 void PhasePeephole::print_statistics() {
1609   tty->print_cr("Peephole: peephole rules applied: %d",  _total_peepholes);
1610 }
1611 #endif
1612 
1613 
1614 //=============================================================================
1615 //------------------------------set_req_X--------------------------------------
1616 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) {
1617   assert( is_not_dead(n), "can not use dead node");
1618   assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" );
1619   Node *old = in(i);
1620   set_req(i, n);
1621 
1622   // old goes dead?
1623   if( old ) {
1624     switch (old->outcnt()) {
1625     case 0:
1626       // Put into the worklist to kill later. We do not kill it now because the
1627       // recursive kill will delete the current node (this) if dead-loop exists
1628       if (!old->is_top())
1629         igvn->_worklist.push( old );
1630       break;
1631     case 1:
1632       if( old->is_Store() || old->has_special_unique_user() )
1633         igvn->add_users_to_worklist( old );
1634       break;
1635     case 2:
1636       if( old->is_Store() )
1637         igvn->add_users_to_worklist( old );
1638       if( old->Opcode() == Op_Region )
1639         igvn->_worklist.push(old);
1640       break;
1641     case 3:
1642       if( old->Opcode() == Op_Region ) {
1643         igvn->_worklist.push(old);
1644         igvn->add_users_to_worklist( old );
1645       }
1646       break;
1647     default:
1648       break;
1649     }