1686 // is removed in PhaseIdealLoop::Dominators().
1687 assert(!r->is_Loop() || r->req() <= 3, "Loop node should have 3 or less inputs");
1688 bool is_loop = (r->is_Loop() && r->req() == 3);
1689 // Then, check if there is a data loop when phi references itself directly
1690 // or through other data nodes.
1691 if (is_loop && !uin->eqv_uncast(in(LoopNode::EntryControl)) ||
1692 !is_loop && is_unsafe_data_reference(uin)) {
1693 // Break this data loop to avoid creation of a dead loop.
1694 if (can_reshape) {
1695 return top;
1696 } else {
1697 // We can't return top if we are in Parse phase - cut inputs only
1698 // let Identity to handle the case.
1699 replace_edge(uin, top);
1700 return NULL;
1701 }
1702 }
1703 }
1704
1705 if (uncasted) {
1706 // Wait until after parsing for the type information to propagate from the casts
1707 assert(can_reshape, "Invalid during parsing");
1708 const Type* phi_type = bottom_type();
1709 assert(phi_type->isa_int() || phi_type->isa_ptr(), "bad phi type");
1710 int opcode;
1711 if (phi_type->isa_int()) {
1712 opcode = Op_CastII;
1713 } else {
1714 const Type* uin_type = phase->type(uin);
1715 if (phi_type->join(TypePtr::NOTNULL) == uin_type->join(TypePtr::NOTNULL)) {
1716 opcode = Op_CastPP;
1717 } else {
1718 opcode = Op_CheckCastPP;
1719 }
1720 }
1721 // Add a cast to carry the control dependency of the Phi that is
1722 // going away
1723 Node* cast = ConstraintCastNode::make_cast(opcode, r, uin, phi_type, true);
1724 cast = phase->transform(cast);
1725 // set all inputs to the new cast so the Phi is removed by Identity
1726 PhaseIterGVN* igvn = phase->is_IterGVN();
1727 for (uint i = 1; i < req(); i++) {
1728 set_req_X(i, cast, igvn);
1729 }
1730 uin = cast;
1731 }
1732
1733 // One unique input.
1734 debug_only(Node* ident = Identity(phase));
1735 // The unique input must eventually be detected by the Identity call.
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1686 // is removed in PhaseIdealLoop::Dominators().
1687 assert(!r->is_Loop() || r->req() <= 3, "Loop node should have 3 or less inputs");
1688 bool is_loop = (r->is_Loop() && r->req() == 3);
1689 // Then, check if there is a data loop when phi references itself directly
1690 // or through other data nodes.
1691 if (is_loop && !uin->eqv_uncast(in(LoopNode::EntryControl)) ||
1692 !is_loop && is_unsafe_data_reference(uin)) {
1693 // Break this data loop to avoid creation of a dead loop.
1694 if (can_reshape) {
1695 return top;
1696 } else {
1697 // We can't return top if we are in Parse phase - cut inputs only
1698 // let Identity to handle the case.
1699 replace_edge(uin, top);
1700 return NULL;
1701 }
1702 }
1703 }
1704
1705 if (uncasted) {
1706 // Add a cast node between the phi to be removed and its unique input.
1707 // Wait until after parsing for the type information to propagate from the casts.
1708 assert(can_reshape, "Invalid during parsing");
1709 const Type* phi_type = bottom_type();
1710 assert(phi_type->isa_int() || phi_type->isa_ptr(), "bad phi type");
1711 int opcode;
1712 // Determine the type of cast to be added.
1713 if (phi_type->isa_int()) {
1714 opcode = Op_CastII;
1715 } else {
1716 const Type* uin_type = phase->type(uin);
1717 if ((phi_type->join(TypePtr::NOTNULL) == uin_type->join(TypePtr::NOTNULL)) ||
1718 (phi_type->isa_klassptr() && uin_type->isa_klassptr())) {
1719 opcode = Op_CastPP;
1720 } else {
1721 opcode = Op_CheckCastPP;
1722 }
1723 }
1724 // Add a cast to carry the control dependency of the Phi that is
1725 // going away
1726 Node* cast = ConstraintCastNode::make_cast(opcode, r, uin, phi_type, true);
1727 cast = phase->transform(cast);
1728 // set all inputs to the new cast so the Phi is removed by Identity
1729 PhaseIterGVN* igvn = phase->is_IterGVN();
1730 for (uint i = 1; i < req(); i++) {
1731 set_req_X(i, cast, igvn);
1732 }
1733 uin = cast;
1734 }
1735
1736 // One unique input.
1737 debug_only(Node* ident = Identity(phase));
1738 // The unique input must eventually be detected by the Identity call.
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