1 /* 2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "memory/allocation.inline.hpp" 26 #include "opto/callnode.hpp" 27 #include "opto/cfgnode.hpp" 28 #include "opto/phaseX.hpp" 29 #include "opto/regmask.hpp" 30 #include "opto/rootnode.hpp" 31 #include "opto/subnode.hpp" 32 #include "opto/type.hpp" 33 34 //------------------------------Ideal------------------------------------------ 35 // Remove dead inputs 36 Node *RootNode::Ideal(PhaseGVN *phase, bool can_reshape) { 37 bool modified = false; 38 for( uint i = 1; i < req(); i++ ) { // For all inputs 39 // Check for and remove dead inputs 40 if( phase->type(in(i)) == Type::TOP ) { 41 del_req(i--); // Delete TOP inputs 42 modified = true; 43 } 44 } 45 46 // I used to do tail-splitting in the Ideal graph here, but it does not 47 // work. The tail-splitting forces values live into the Return to be 48 // ready at a point which dominates the split returns. This forces Stores 49 // to be hoisted high. The "proper" fix would be to split Stores down 50 // each path, but this makes the split unprofitable. If we want to do this 51 // optimization, it needs to be done after allocation so we can count all 52 // the instructions needing to be cloned in the cost metric. 53 54 // There used to be a spoof here for caffeine marks which completely 55 // eliminated very simple self-recursion recursions, but it's not worth it. 56 // Deep inlining of self-calls gets nearly all of the same benefits. 57 // If we want to get the rest of the win later, we should pattern match 58 // simple recursive call trees to closed-form solutions. 59 60 return modified ? this : nullptr; 61 } 62 63 //============================================================================= 64 HaltNode::HaltNode(Node* ctrl, Node* frameptr, const char* halt_reason, bool reachable) 65 : Node(TypeFunc::Parms), _halt_reason(halt_reason), _reachable(reachable) { 66 init_class_id(Class_Halt); 67 Node* top = Compile::current()->top(); 68 init_req(TypeFunc::Control, ctrl ); 69 init_req(TypeFunc::I_O, top); 70 init_req(TypeFunc::Memory, top); 71 init_req(TypeFunc::FramePtr, frameptr ); 72 init_req(TypeFunc::ReturnAdr,top); 73 } 74 75 const Type *HaltNode::bottom_type() const { return Type::BOTTOM; } 76 uint HaltNode::size_of() const { return sizeof(*this); } 77 78 //------------------------------Ideal------------------------------------------ 79 Node *HaltNode::Ideal(PhaseGVN *phase, bool can_reshape) { 80 return remove_dead_region(phase, can_reshape) ? this : nullptr; 81 } 82 83 //------------------------------Value------------------------------------------ 84 const Type* HaltNode::Value(PhaseGVN* phase) const { 85 return ( phase->type(in(TypeFunc::Control)) == Type::TOP) 86 ? Type::TOP 87 : Type::BOTTOM; 88 } 89 90 const RegMask &HaltNode::out_RegMask() const { 91 return RegMask::Empty; 92 } --- EOF ---