1 /* 2 * Copyright (c) 2016, 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 "precompiled.hpp" 26 #include "memory/resourceArea.hpp" 27 #include "opto/cfgnode.hpp" 28 #include "opto/phaseX.hpp" 29 #include "opto/replacednodes.hpp" 30 31 void ReplacedNodes::allocate_if_necessary() { 32 if (_replaced_nodes == NULL) { 33 _replaced_nodes = new GrowableArray<ReplacedNode>(); 34 } 35 } 36 37 bool ReplacedNodes::is_empty() const { 38 return _replaced_nodes == NULL || _replaced_nodes->length() == 0; 39 } 40 41 bool ReplacedNodes::has_node(const ReplacedNode& r) const { 42 return _replaced_nodes->find(r) != -1; 43 } 44 45 bool ReplacedNodes::has_target_node(Node* n) const { 46 for (int i = 0; i < _replaced_nodes->length(); i++) { 47 if (_replaced_nodes->at(i).improved() == n) { 48 return true; 49 } 50 } 51 return false; 52 } 53 54 // Record replaced node if not seen before 55 void ReplacedNodes::record(Node* initial, Node* improved) { 56 allocate_if_necessary(); 57 ReplacedNode r(initial, improved); 58 if (!has_node(r)) { 59 _replaced_nodes->push(r); 60 } 61 } 62 63 // Copy replaced nodes from one map to another. idx is used to 64 // identify nodes that are too new to be of interest in the target 65 // node list. 66 void ReplacedNodes::transfer_from(const ReplacedNodes& other, uint idx) { 67 if (other.is_empty()) { 68 return; 69 } 70 allocate_if_necessary(); 71 for (int i = 0; i < other._replaced_nodes->length(); i++) { 72 ReplacedNode replaced = other._replaced_nodes->at(i); 73 // Only transfer the nodes that can actually be useful 74 if (!has_node(replaced) && (replaced.initial()->_idx < idx || has_target_node(replaced.initial()))) { 75 _replaced_nodes->push(replaced); 76 } 77 } 78 } 79 80 void ReplacedNodes::clone() { 81 if (_replaced_nodes != NULL) { 82 GrowableArray<ReplacedNode>* replaced_nodes_clone = new GrowableArray<ReplacedNode>(); 83 replaced_nodes_clone->appendAll(_replaced_nodes); 84 _replaced_nodes = replaced_nodes_clone; 85 } 86 } 87 88 void ReplacedNodes::reset() { 89 if (_replaced_nodes != NULL) { 90 _replaced_nodes->clear(); 91 } 92 } 93 94 // Perfom node replacement (used when returning to caller) 95 void ReplacedNodes::apply(Node* n) { 96 if (is_empty()) { 97 return; 98 } 99 for (int i = 0; i < _replaced_nodes->length(); i++) { 100 ReplacedNode replaced = _replaced_nodes->at(i); 101 n->replace_edge(replaced.initial(), replaced.improved()); 102 } 103 } 104 105 static void enqueue_use(Node* n, Node* use, Unique_Node_List& work) { 106 if (use->is_Phi()) { 107 Node* r = use->in(0); 108 assert(r->is_Region(), "Phi should have Region"); 109 for (uint i = 1; i < use->req(); i++) { 110 if (use->in(i) == n) { 111 work.push(r->in(i)); 112 } 113 } 114 } else { 115 work.push(use); 116 } 117 } 118 119 // Perfom node replacement following late inlining 120 void ReplacedNodes::apply(Compile* C, Node* ctl) { 121 // ctl is the control on exit of the method that was late inlined 122 if (is_empty()) { 123 return; 124 } 125 for (int i = 0; i < _replaced_nodes->length(); i++) { 126 ReplacedNode replaced = _replaced_nodes->at(i); 127 Node* initial = replaced.initial(); 128 Node* improved = replaced.improved(); 129 assert (ctl != NULL && !ctl->is_top(), "replaced node should have actual control"); 130 131 ResourceMark rm; 132 Unique_Node_List work; 133 // Go over all the uses of the node that is considered for replacement... 134 for (DUIterator j = initial->outs(); initial->has_out(j); j++) { 135 Node* use = initial->out(j); 136 137 if (use == improved || use->outcnt() == 0) { 138 continue; 139 } 140 work.clear(); 141 enqueue_use(initial, use, work); 142 bool replace = true; 143 // Check that this use is dominated by ctl. Go ahead with the 144 // replacement if it is. 145 while (work.size() != 0 && replace) { 146 Node* n = work.pop(); 147 if (use->outcnt() == 0) { 148 continue; 149 } 150 if (n->is_CFG() || (n->in(0) != NULL && !n->in(0)->is_top())) { 151 int depth = 0; 152 Node *m = n; 153 if (!n->is_CFG()) { 154 n = n->in(0); 155 } 156 assert(n->is_CFG(), "should be CFG now"); 157 while(n != ctl) { 158 n = IfNode::up_one_dom(n); 159 depth++; 160 // limit search depth 161 if (depth >= 100 || n == NULL) { 162 replace = false; 163 break; 164 } 165 } 166 } else { 167 for (DUIterator k = n->outs(); n->has_out(k); k++) { 168 enqueue_use(n, n->out(k), work); 169 } 170 } 171 } 172 if (replace) { 173 bool is_in_table = C->initial_gvn()->hash_delete(use); 174 int replaced = use->replace_edge(initial, improved); 175 if (is_in_table) { 176 C->initial_gvn()->hash_find_insert(use); 177 } 178 C->record_for_igvn(use); 179 180 assert(replaced > 0, "inconsistent"); 181 --j; 182 } 183 } 184 } 185 } 186 187 void ReplacedNodes::dump(outputStream *st) const { 188 if (!is_empty()) { 189 st->print("replaced nodes: "); 190 for (int i = 0; i < _replaced_nodes->length(); i++) { 191 st->print("%d->%d", _replaced_nodes->at(i).initial()->_idx, _replaced_nodes->at(i).improved()->_idx); 192 if (i < _replaced_nodes->length()-1) { 193 st->print(","); 194 } 195 } 196 } 197 } 198 199 // Merge 2 list of replaced node at a point where control flow paths merge 200 void ReplacedNodes::merge_with(const ReplacedNodes& other) { 201 if (is_empty()) { 202 return; 203 } 204 if (other.is_empty()) { 205 reset(); 206 return; 207 } 208 int shift = 0; 209 int len = _replaced_nodes->length(); 210 for (int i = 0; i < len; i++) { 211 if (!other.has_node(_replaced_nodes->at(i))) { 212 shift++; 213 } else if (shift > 0) { 214 _replaced_nodes->at_put(i-shift, _replaced_nodes->at(i)); 215 } 216 } 217 if (shift > 0) { 218 _replaced_nodes->trunc_to(len - shift); 219 } 220 }