1 /* 2 * Copyright (c) 2014, 2019, 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 #ifndef SHARE_OPTO_REPLACEDNODES_HPP 26 #define SHARE_OPTO_REPLACEDNODES_HPP 27 28 #include "opto/connode.hpp" 29 30 // During parsing, when a node is "improved", 31 // GraphKit::replace_in_map() is called to update the current map so 32 // that the improved node is used from that point 33 // on. GraphKit::replace_in_map() doesn't operate on the callers maps 34 // and so some optimization opportunities may be lost. The 35 // ReplacedNodes class addresses that problem. 36 // 37 // A ReplacedNodes object is a list of pair of nodes. Every 38 // SafePointNode carries a ReplacedNodes object. Every time 39 // GraphKit::replace_in_map() is called, a new pair of nodes is pushed 40 // on the list of replaced nodes. When control flow paths merge, their 41 // replaced nodes are also merged. When parsing exits a method to 42 // return to a caller, the replaced nodes on the exit path are used to 43 // update the caller's map. 44 class ReplacedNodes { 45 private: 46 class ReplacedNode { 47 private: 48 Node* _initial; 49 Node* _improved; 50 public: ReplacedNode()51 ReplacedNode() : _initial(NULL), _improved(NULL) {} ReplacedNode(Node * initial,Node * improved)52 ReplacedNode(Node* initial, Node* improved) : _initial(initial), _improved(improved) {} initial() const53 Node* initial() const { return _initial; } improved() const54 Node* improved() const { return _improved; } 55 operator ==(const ReplacedNode & other)56 bool operator==(const ReplacedNode& other) { 57 return _initial == other._initial && _improved == other._improved; 58 } 59 }; 60 GrowableArray<ReplacedNode>* _replaced_nodes; 61 62 void allocate_if_necessary(); 63 bool has_node(const ReplacedNode& r) const; 64 bool has_target_node(Node* n) const; 65 66 public: ReplacedNodes()67 ReplacedNodes() 68 : _replaced_nodes(NULL) {} 69 70 void clone(); 71 void record(Node* initial, Node* improved); 72 void transfer_from(const ReplacedNodes& other, uint idx); 73 void reset(); 74 void apply(Node* n, uint idx); 75 void merge_with(const ReplacedNodes& other); 76 bool is_empty() const; 77 void dump(outputStream *st) const; 78 void apply(Compile* C, Node* ctl); 79 }; 80 81 #endif // SHARE_OPTO_REPLACEDNODES_HPP 82