656 //------------------------------fold_compares----------------------------
 657 // See if a pair of CmpIs can be converted into a CmpU.  In some cases
 658 // the direction of this if is determined by the preceding if so it
 659 // can be eliminate entirely.  Given an if testing (CmpI n c) check
 660 // for an immediately control dependent if that is testing (CmpI n c2)
 661 // and has one projection leading to this if and the other projection
 662 // leading to a region that merges one of this ifs control
 663 // projections.
 664 //
 665 //                   If
 666 //                  / |
 667 //                 /  |
 668 //                /   |
 669 //              If    |
 670 //              /\    |
 671 //             /  \   |
 672 //            /    \  |
 673 //           /    Region
 674 //
 675 Node* IfNode::fold_compares(PhaseGVN* phase) {
 676   if (!phase->C->eliminate_boxing() || Opcode() != Op_If) return NULL;
 677 
 678   Node* this_cmp = in(1)->in(1);
 679   if (this_cmp != NULL && this_cmp->Opcode() == Op_CmpI &&
 680       this_cmp->in(2)->is_Con() && this_cmp->in(2) != phase->C->top()) {
 681     Node* ctrl = in(0);
 682     BoolNode* this_bool = in(1)->as_Bool();
 683     Node* n = this_cmp->in(1);
 684     int hi = this_cmp->in(2)->get_int();
 685     if (ctrl != NULL && ctrl->is_Proj() && ctrl->outcnt() == 1 &&
 686         ctrl->in(0)->is_If() &&
 687         ctrl->in(0)->outcnt() == 2 &&
 688         ctrl->in(0)->in(1)->is_Bool() &&
 689         ctrl->in(0)->in(1)->in(1)->Opcode() == Op_CmpI &&
 690         ctrl->in(0)->in(1)->in(1)->in(2)->is_Con() &&
 691         ctrl->in(0)->in(1)->in(1)->in(2) != phase->C->top() &&
 692         ctrl->in(0)->in(1)->in(1)->in(1) == n) {
 693       IfNode* dom_iff = ctrl->in(0)->as_If();
 694       Node* otherproj = dom_iff->proj_out(!ctrl->as_Proj()->_con);
 695       if (otherproj->outcnt() == 1 && otherproj->unique_out()->is_Region() &&
 696           this_bool->_test._test != BoolTest::ne && this_bool->_test._test != BoolTest::eq) {

 656 //------------------------------fold_compares----------------------------
 657 // See if a pair of CmpIs can be converted into a CmpU.  In some cases
 658 // the direction of this if is determined by the preceding if so it
 659 // can be eliminate entirely.  Given an if testing (CmpI n c) check
 660 // for an immediately control dependent if that is testing (CmpI n c2)
 661 // and has one projection leading to this if and the other projection
 662 // leading to a region that merges one of this ifs control
 663 // projections.
 664 //
 665 //                   If
 666 //                  / |
 667 //                 /  |
 668 //                /   |
 669 //              If    |
 670 //              /\    |
 671 //             /  \   |
 672 //            /    \  |
 673 //           /    Region
 674 //
 675 Node* IfNode::fold_compares(PhaseGVN* phase) {
 676   if (Opcode() != Op_If) return NULL;
 677 
 678   Node* this_cmp = in(1)->in(1);
 679   if (this_cmp != NULL && this_cmp->Opcode() == Op_CmpI &&
 680       this_cmp->in(2)->is_Con() && this_cmp->in(2) != phase->C->top()) {
 681     Node* ctrl = in(0);
 682     BoolNode* this_bool = in(1)->as_Bool();
 683     Node* n = this_cmp->in(1);
 684     int hi = this_cmp->in(2)->get_int();
 685     if (ctrl != NULL && ctrl->is_Proj() && ctrl->outcnt() == 1 &&
 686         ctrl->in(0)->is_If() &&
 687         ctrl->in(0)->outcnt() == 2 &&
 688         ctrl->in(0)->in(1)->is_Bool() &&
 689         ctrl->in(0)->in(1)->in(1)->Opcode() == Op_CmpI &&
 690         ctrl->in(0)->in(1)->in(1)->in(2)->is_Con() &&
 691         ctrl->in(0)->in(1)->in(1)->in(2) != phase->C->top() &&
 692         ctrl->in(0)->in(1)->in(1)->in(1) == n) {
 693       IfNode* dom_iff = ctrl->in(0)->as_If();
 694       Node* otherproj = dom_iff->proj_out(!ctrl->as_Proj()->_con);
 695       if (otherproj->outcnt() == 1 && otherproj->unique_out()->is_Region() &&
 696           this_bool->_test._test != BoolTest::ne && this_bool->_test._test != BoolTest::eq) {