1 /*
   2  * Copyright (c) 1997, 2022, 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 "gc/shared/barrierSet.hpp"
  27 #include "gc/shared/c2/barrierSetC2.hpp"
  28 #include "libadt/vectset.hpp"
  29 #include "memory/allocation.inline.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "opto/ad.hpp"
  32 #include "opto/callGenerator.hpp"
  33 #include "opto/castnode.hpp"
  34 #include "opto/cfgnode.hpp"
  35 #include "opto/connode.hpp"
  36 #include "opto/loopnode.hpp"
  37 #include "opto/machnode.hpp"
  38 #include "opto/matcher.hpp"
  39 #include "opto/node.hpp"
  40 #include "opto/opcodes.hpp"
  41 #include "opto/regmask.hpp"
  42 #include "opto/rootnode.hpp"
  43 #include "opto/type.hpp"
  44 #include "utilities/copy.hpp"
  45 #include "utilities/macros.hpp"
  46 #include "utilities/powerOfTwo.hpp"
  47 #include "utilities/stringUtils.hpp"
  48 
  49 class RegMask;
  50 // #include "phase.hpp"
  51 class PhaseTransform;
  52 class PhaseGVN;
  53 
  54 // Arena we are currently building Nodes in
  55 const uint Node::NotAMachineReg = 0xffff0000;
  56 
  57 #ifndef PRODUCT
  58 extern int nodes_created;
  59 #endif
  60 #ifdef __clang__
  61 #pragma clang diagnostic push
  62 #pragma GCC diagnostic ignored "-Wuninitialized"
  63 #endif
  64 
  65 #ifdef ASSERT
  66 
  67 //-------------------------- construct_node------------------------------------
  68 // Set a breakpoint here to identify where a particular node index is built.
  69 void Node::verify_construction() {
  70   _debug_orig = NULL;
  71   int old_debug_idx = Compile::debug_idx();
  72   int new_debug_idx = old_debug_idx + 1;
  73   if (new_debug_idx > 0) {
  74     // Arrange that the lowest five decimal digits of _debug_idx
  75     // will repeat those of _idx. In case this is somehow pathological,
  76     // we continue to assign negative numbers (!) consecutively.
  77     const int mod = 100000;
  78     int bump = (int)(_idx - new_debug_idx) % mod;
  79     if (bump < 0) {
  80       bump += mod;
  81     }
  82     assert(bump >= 0 && bump < mod, "");
  83     new_debug_idx += bump;
  84   }
  85   Compile::set_debug_idx(new_debug_idx);
  86   set_debug_idx(new_debug_idx);
  87   Compile* C = Compile::current();
  88   assert(C->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
  89   if (!C->phase_optimize_finished()) {
  90     // Only check assert during parsing and optimization phase. Skip it while generating code.
  91     assert(C->live_nodes() <= C->max_node_limit(), "Live Node limit exceeded limit");
  92   }
  93   if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
  94     tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
  95     BREAKPOINT;
  96   }
  97 #if OPTO_DU_ITERATOR_ASSERT
  98   _last_del = NULL;
  99   _del_tick = 0;
 100 #endif
 101   _hash_lock = 0;
 102 }
 103 
 104 
 105 // #ifdef ASSERT ...
 106 
 107 #if OPTO_DU_ITERATOR_ASSERT
 108 void DUIterator_Common::sample(const Node* node) {
 109   _vdui     = VerifyDUIterators;
 110   _node     = node;
 111   _outcnt   = node->_outcnt;
 112   _del_tick = node->_del_tick;
 113   _last     = NULL;
 114 }
 115 
 116 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
 117   assert(_node     == node, "consistent iterator source");
 118   assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
 119 }
 120 
 121 void DUIterator_Common::verify_resync() {
 122   // Ensure that the loop body has just deleted the last guy produced.
 123   const Node* node = _node;
 124   // Ensure that at least one copy of the last-seen edge was deleted.
 125   // Note:  It is OK to delete multiple copies of the last-seen edge.
 126   // Unfortunately, we have no way to verify that all the deletions delete
 127   // that same edge.  On this point we must use the Honor System.
 128   assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
 129   assert(node->_last_del == _last, "must have deleted the edge just produced");
 130   // We liked this deletion, so accept the resulting outcnt and tick.
 131   _outcnt   = node->_outcnt;
 132   _del_tick = node->_del_tick;
 133 }
 134 
 135 void DUIterator_Common::reset(const DUIterator_Common& that) {
 136   if (this == &that)  return;  // ignore assignment to self
 137   if (!_vdui) {
 138     // We need to initialize everything, overwriting garbage values.
 139     _last = that._last;
 140     _vdui = that._vdui;
 141   }
 142   // Note:  It is legal (though odd) for an iterator over some node x
 143   // to be reassigned to iterate over another node y.  Some doubly-nested
 144   // progress loops depend on being able to do this.
 145   const Node* node = that._node;
 146   // Re-initialize everything, except _last.
 147   _node     = node;
 148   _outcnt   = node->_outcnt;
 149   _del_tick = node->_del_tick;
 150 }
 151 
 152 void DUIterator::sample(const Node* node) {
 153   DUIterator_Common::sample(node);      // Initialize the assertion data.
 154   _refresh_tick = 0;                    // No refreshes have happened, as yet.
 155 }
 156 
 157 void DUIterator::verify(const Node* node, bool at_end_ok) {
 158   DUIterator_Common::verify(node, at_end_ok);
 159   assert(_idx      <  node->_outcnt + (uint)at_end_ok, "idx in range");
 160 }
 161 
 162 void DUIterator::verify_increment() {
 163   if (_refresh_tick & 1) {
 164     // We have refreshed the index during this loop.
 165     // Fix up _idx to meet asserts.
 166     if (_idx > _outcnt)  _idx = _outcnt;
 167   }
 168   verify(_node, true);
 169 }
 170 
 171 void DUIterator::verify_resync() {
 172   // Note:  We do not assert on _outcnt, because insertions are OK here.
 173   DUIterator_Common::verify_resync();
 174   // Make sure we are still in sync, possibly with no more out-edges:
 175   verify(_node, true);
 176 }
 177 
 178 void DUIterator::reset(const DUIterator& that) {
 179   if (this == &that)  return;  // self assignment is always a no-op
 180   assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
 181   assert(that._idx          == 0, "assign only the result of Node::outs()");
 182   assert(_idx               == that._idx, "already assigned _idx");
 183   if (!_vdui) {
 184     // We need to initialize everything, overwriting garbage values.
 185     sample(that._node);
 186   } else {
 187     DUIterator_Common::reset(that);
 188     if (_refresh_tick & 1) {
 189       _refresh_tick++;                  // Clear the "was refreshed" flag.
 190     }
 191     assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
 192   }
 193 }
 194 
 195 void DUIterator::refresh() {
 196   DUIterator_Common::sample(_node);     // Re-fetch assertion data.
 197   _refresh_tick |= 1;                   // Set the "was refreshed" flag.
 198 }
 199 
 200 void DUIterator::verify_finish() {
 201   // If the loop has killed the node, do not require it to re-run.
 202   if (_node->_outcnt == 0)  _refresh_tick &= ~1;
 203   // If this assert triggers, it means that a loop used refresh_out_pos
 204   // to re-synch an iteration index, but the loop did not correctly
 205   // re-run itself, using a "while (progress)" construct.
 206   // This iterator enforces the rule that you must keep trying the loop
 207   // until it "runs clean" without any need for refreshing.
 208   assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
 209 }
 210 
 211 
 212 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
 213   DUIterator_Common::verify(node, at_end_ok);
 214   Node** out    = node->_out;
 215   uint   cnt    = node->_outcnt;
 216   assert(cnt == _outcnt, "no insertions allowed");
 217   assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
 218   // This last check is carefully designed to work for NO_OUT_ARRAY.
 219 }
 220 
 221 void DUIterator_Fast::verify_limit() {
 222   const Node* node = _node;
 223   verify(node, true);
 224   assert(_outp == node->_out + node->_outcnt, "limit still correct");
 225 }
 226 
 227 void DUIterator_Fast::verify_resync() {
 228   const Node* node = _node;
 229   if (_outp == node->_out + _outcnt) {
 230     // Note that the limit imax, not the pointer i, gets updated with the
 231     // exact count of deletions.  (For the pointer it's always "--i".)
 232     assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
 233     // This is a limit pointer, with a name like "imax".
 234     // Fudge the _last field so that the common assert will be happy.
 235     _last = (Node*) node->_last_del;
 236     DUIterator_Common::verify_resync();
 237   } else {
 238     assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
 239     // A normal internal pointer.
 240     DUIterator_Common::verify_resync();
 241     // Make sure we are still in sync, possibly with no more out-edges:
 242     verify(node, true);
 243   }
 244 }
 245 
 246 void DUIterator_Fast::verify_relimit(uint n) {
 247   const Node* node = _node;
 248   assert((int)n > 0, "use imax -= n only with a positive count");
 249   // This must be a limit pointer, with a name like "imax".
 250   assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
 251   // The reported number of deletions must match what the node saw.
 252   assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
 253   // Fudge the _last field so that the common assert will be happy.
 254   _last = (Node*) node->_last_del;
 255   DUIterator_Common::verify_resync();
 256 }
 257 
 258 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
 259   assert(_outp              == that._outp, "already assigned _outp");
 260   DUIterator_Common::reset(that);
 261 }
 262 
 263 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
 264   // at_end_ok means the _outp is allowed to underflow by 1
 265   _outp += at_end_ok;
 266   DUIterator_Fast::verify(node, at_end_ok);  // check _del_tick, etc.
 267   _outp -= at_end_ok;
 268   assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
 269 }
 270 
 271 void DUIterator_Last::verify_limit() {
 272   // Do not require the limit address to be resynched.
 273   //verify(node, true);
 274   assert(_outp == _node->_out, "limit still correct");
 275 }
 276 
 277 void DUIterator_Last::verify_step(uint num_edges) {
 278   assert((int)num_edges > 0, "need non-zero edge count for loop progress");
 279   _outcnt   -= num_edges;
 280   _del_tick += num_edges;
 281   // Make sure we are still in sync, possibly with no more out-edges:
 282   const Node* node = _node;
 283   verify(node, true);
 284   assert(node->_last_del == _last, "must have deleted the edge just produced");
 285 }
 286 
 287 #endif //OPTO_DU_ITERATOR_ASSERT
 288 
 289 
 290 #endif //ASSERT
 291 
 292 
 293 // This constant used to initialize _out may be any non-null value.
 294 // The value NULL is reserved for the top node only.
 295 #define NO_OUT_ARRAY ((Node**)-1)
 296 
 297 // Out-of-line code from node constructors.
 298 // Executed only when extra debug info. is being passed around.
 299 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
 300   C->set_node_notes_at(idx, nn);
 301 }
 302 
 303 // Shared initialization code.
 304 inline int Node::Init(int req) {
 305   Compile* C = Compile::current();
 306   int idx = C->next_unique();
 307   NOT_PRODUCT(_igv_idx = C->next_igv_idx());
 308 
 309   // Allocate memory for the necessary number of edges.
 310   if (req > 0) {
 311     // Allocate space for _in array to have double alignment.
 312     _in = (Node **) ((char *) (C->node_arena()->AmallocWords(req * sizeof(void*))));
 313   }
 314   // If there are default notes floating around, capture them:
 315   Node_Notes* nn = C->default_node_notes();
 316   if (nn != NULL)  init_node_notes(C, idx, nn);
 317 
 318   // Note:  At this point, C is dead,
 319   // and we begin to initialize the new Node.
 320 
 321   _cnt = _max = req;
 322   _outcnt = _outmax = 0;
 323   _class_id = Class_Node;
 324   _flags = 0;
 325   _out = NO_OUT_ARRAY;
 326   return idx;
 327 }
 328 
 329 //------------------------------Node-------------------------------------------
 330 // Create a Node, with a given number of required edges.
 331 Node::Node(uint req)
 332   : _idx(Init(req))
 333 #ifdef ASSERT
 334   , _parse_idx(_idx)
 335 #endif
 336 {
 337   assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
 338   debug_only( verify_construction() );
 339   NOT_PRODUCT(nodes_created++);
 340   if (req == 0) {
 341     _in = NULL;
 342   } else {
 343     Node** to = _in;
 344     for(uint i = 0; i < req; i++) {
 345       to[i] = NULL;
 346     }
 347   }
 348 }
 349 
 350 //------------------------------Node-------------------------------------------
 351 Node::Node(Node *n0)
 352   : _idx(Init(1))
 353 #ifdef ASSERT
 354   , _parse_idx(_idx)
 355 #endif
 356 {
 357   debug_only( verify_construction() );
 358   NOT_PRODUCT(nodes_created++);
 359   assert( is_not_dead(n0), "can not use dead node");
 360   _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
 361 }
 362 
 363 //------------------------------Node-------------------------------------------
 364 Node::Node(Node *n0, Node *n1)
 365   : _idx(Init(2))
 366 #ifdef ASSERT
 367   , _parse_idx(_idx)
 368 #endif
 369 {
 370   debug_only( verify_construction() );
 371   NOT_PRODUCT(nodes_created++);
 372   assert( is_not_dead(n0), "can not use dead node");
 373   assert( is_not_dead(n1), "can not use dead node");
 374   _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
 375   _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
 376 }
 377 
 378 //------------------------------Node-------------------------------------------
 379 Node::Node(Node *n0, Node *n1, Node *n2)
 380   : _idx(Init(3))
 381 #ifdef ASSERT
 382   , _parse_idx(_idx)
 383 #endif
 384 {
 385   debug_only( verify_construction() );
 386   NOT_PRODUCT(nodes_created++);
 387   assert( is_not_dead(n0), "can not use dead node");
 388   assert( is_not_dead(n1), "can not use dead node");
 389   assert( is_not_dead(n2), "can not use dead node");
 390   _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
 391   _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
 392   _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
 393 }
 394 
 395 //------------------------------Node-------------------------------------------
 396 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
 397   : _idx(Init(4))
 398 #ifdef ASSERT
 399   , _parse_idx(_idx)
 400 #endif
 401 {
 402   debug_only( verify_construction() );
 403   NOT_PRODUCT(nodes_created++);
 404   assert( is_not_dead(n0), "can not use dead node");
 405   assert( is_not_dead(n1), "can not use dead node");
 406   assert( is_not_dead(n2), "can not use dead node");
 407   assert( is_not_dead(n3), "can not use dead node");
 408   _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
 409   _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
 410   _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
 411   _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
 412 }
 413 
 414 //------------------------------Node-------------------------------------------
 415 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
 416   : _idx(Init(5))
 417 #ifdef ASSERT
 418   , _parse_idx(_idx)
 419 #endif
 420 {
 421   debug_only( verify_construction() );
 422   NOT_PRODUCT(nodes_created++);
 423   assert( is_not_dead(n0), "can not use dead node");
 424   assert( is_not_dead(n1), "can not use dead node");
 425   assert( is_not_dead(n2), "can not use dead node");
 426   assert( is_not_dead(n3), "can not use dead node");
 427   assert( is_not_dead(n4), "can not use dead node");
 428   _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
 429   _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
 430   _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
 431   _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
 432   _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
 433 }
 434 
 435 //------------------------------Node-------------------------------------------
 436 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
 437                      Node *n4, Node *n5)
 438   : _idx(Init(6))
 439 #ifdef ASSERT
 440   , _parse_idx(_idx)
 441 #endif
 442 {
 443   debug_only( verify_construction() );
 444   NOT_PRODUCT(nodes_created++);
 445   assert( is_not_dead(n0), "can not use dead node");
 446   assert( is_not_dead(n1), "can not use dead node");
 447   assert( is_not_dead(n2), "can not use dead node");
 448   assert( is_not_dead(n3), "can not use dead node");
 449   assert( is_not_dead(n4), "can not use dead node");
 450   assert( is_not_dead(n5), "can not use dead node");
 451   _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
 452   _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
 453   _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
 454   _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
 455   _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
 456   _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
 457 }
 458 
 459 //------------------------------Node-------------------------------------------
 460 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
 461                      Node *n4, Node *n5, Node *n6)
 462   : _idx(Init(7))
 463 #ifdef ASSERT
 464   , _parse_idx(_idx)
 465 #endif
 466 {
 467   debug_only( verify_construction() );
 468   NOT_PRODUCT(nodes_created++);
 469   assert( is_not_dead(n0), "can not use dead node");
 470   assert( is_not_dead(n1), "can not use dead node");
 471   assert( is_not_dead(n2), "can not use dead node");
 472   assert( is_not_dead(n3), "can not use dead node");
 473   assert( is_not_dead(n4), "can not use dead node");
 474   assert( is_not_dead(n5), "can not use dead node");
 475   assert( is_not_dead(n6), "can not use dead node");
 476   _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
 477   _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
 478   _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
 479   _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
 480   _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
 481   _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
 482   _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
 483 }
 484 
 485 #ifdef __clang__
 486 #pragma clang diagnostic pop
 487 #endif
 488 
 489 
 490 //------------------------------clone------------------------------------------
 491 // Clone a Node.
 492 Node *Node::clone() const {
 493   Compile* C = Compile::current();
 494   uint s = size_of();           // Size of inherited Node
 495   Node *n = (Node*)C->node_arena()->AmallocWords(size_of() + _max*sizeof(Node*));
 496   Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
 497   // Set the new input pointer array
 498   n->_in = (Node**)(((char*)n)+s);
 499   // Cannot share the old output pointer array, so kill it
 500   n->_out = NO_OUT_ARRAY;
 501   // And reset the counters to 0
 502   n->_outcnt = 0;
 503   n->_outmax = 0;
 504   // Unlock this guy, since he is not in any hash table.
 505   debug_only(n->_hash_lock = 0);
 506   // Walk the old node's input list to duplicate its edges
 507   uint i;
 508   for( i = 0; i < len(); i++ ) {
 509     Node *x = in(i);
 510     n->_in[i] = x;
 511     if (x != NULL) x->add_out(n);
 512   }
 513   if (is_macro()) {
 514     C->add_macro_node(n);
 515   }
 516   if (is_expensive()) {
 517     C->add_expensive_node(n);
 518   }
 519   if (for_post_loop_opts_igvn()) {
 520     // Don't add cloned node to Compile::_for_post_loop_opts_igvn list automatically.
 521     // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
 522     n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
 523   }
 524   if (n->is_reduction()) {
 525     // Do not copy reduction information. This must be explicitly set by the calling code.
 526     n->remove_flag(Node::Flag_is_reduction);
 527   }
 528   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 529   bs->register_potential_barrier_node(n);
 530 
 531   n->set_idx(C->next_unique()); // Get new unique index as well
 532   NOT_PRODUCT(n->_igv_idx = C->next_igv_idx());
 533   debug_only( n->verify_construction() );
 534   NOT_PRODUCT(nodes_created++);
 535   // Do not patch over the debug_idx of a clone, because it makes it
 536   // impossible to break on the clone's moment of creation.
 537   //debug_only( n->set_debug_idx( debug_idx() ) );
 538 
 539   C->copy_node_notes_to(n, (Node*) this);
 540 
 541   // MachNode clone
 542   uint nopnds;
 543   if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
 544     MachNode *mach  = n->as_Mach();
 545     MachNode *mthis = this->as_Mach();
 546     // Get address of _opnd_array.
 547     // It should be the same offset since it is the clone of this node.
 548     MachOper **from = mthis->_opnds;
 549     MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
 550                     pointer_delta((const void*)from,
 551                                   (const void*)(&mthis->_opnds), 1));
 552     mach->_opnds = to;
 553     for ( uint i = 0; i < nopnds; ++i ) {
 554       to[i] = from[i]->clone();
 555     }
 556   }
 557   if (n->is_Call()) {
 558     // CallGenerator is linked to the original node.
 559     CallGenerator* cg = n->as_Call()->generator();
 560     if (cg != NULL) {
 561       CallGenerator* cloned_cg = cg->with_call_node(n->as_Call());
 562       n->as_Call()->set_generator(cloned_cg);
 563 
 564       C->print_inlining_assert_ready();
 565       C->print_inlining_move_to(cg);
 566       C->print_inlining_update(cloned_cg);
 567     }
 568   }
 569   if (n->is_SafePoint()) {
 570     // Scalar replacement and macro expansion might modify the JVMState.
 571     // Clone it to make sure it's not shared between SafePointNodes.
 572     n->as_SafePoint()->clone_jvms(C);
 573     n->as_SafePoint()->clone_replaced_nodes();
 574   }
 575   if (n->is_InlineTypeBase()) {
 576     C->add_inline_type(n);
 577   }
 578   Compile::current()->record_modified_node(n);
 579   return n;                     // Return the clone
 580 }
 581 
 582 //---------------------------setup_is_top--------------------------------------
 583 // Call this when changing the top node, to reassert the invariants
 584 // required by Node::is_top.  See Compile::set_cached_top_node.
 585 void Node::setup_is_top() {
 586   if (this == (Node*)Compile::current()->top()) {
 587     // This node has just become top.  Kill its out array.
 588     _outcnt = _outmax = 0;
 589     _out = NULL;                           // marker value for top
 590     assert(is_top(), "must be top");
 591   } else {
 592     if (_out == NULL)  _out = NO_OUT_ARRAY;
 593     assert(!is_top(), "must not be top");
 594   }
 595 }
 596 
 597 //------------------------------~Node------------------------------------------
 598 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 599 void Node::destruct(PhaseValues* phase) {
 600   Compile* compile = (phase != NULL) ? phase->C : Compile::current();
 601   if (phase != NULL && phase->is_IterGVN()) {
 602     phase->is_IterGVN()->_worklist.remove(this);
 603   }
 604   // If this is the most recently created node, reclaim its index. Otherwise,
 605   // record the node as dead to keep liveness information accurate.
 606   if ((uint)_idx+1 == compile->unique()) {
 607     compile->set_unique(compile->unique()-1);
 608   } else {
 609     compile->record_dead_node(_idx);
 610   }
 611   // Clear debug info:
 612   Node_Notes* nn = compile->node_notes_at(_idx);
 613   if (nn != NULL)  nn->clear();
 614   // Walk the input array, freeing the corresponding output edges
 615   _cnt = _max;  // forget req/prec distinction
 616   uint i;
 617   for( i = 0; i < _max; i++ ) {
 618     set_req(i, NULL);
 619     //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
 620   }
 621   assert(outcnt() == 0, "deleting a node must not leave a dangling use");
 622   // See if the input array was allocated just prior to the object
 623   int edge_size = _max*sizeof(void*);
 624   int out_edge_size = _outmax*sizeof(void*);
 625   char *edge_end = ((char*)_in) + edge_size;
 626   char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
 627   int node_size = size_of();
 628 
 629   // Free the output edge array
 630   if (out_edge_size > 0) {
 631     compile->node_arena()->Afree(out_array, out_edge_size);
 632   }
 633 
 634   // Free the input edge array and the node itself
 635   if( edge_end == (char*)this ) {
 636     // It was; free the input array and object all in one hit
 637 #ifndef ASSERT
 638     compile->node_arena()->Afree(_in,edge_size+node_size);
 639 #endif
 640   } else {
 641     // Free just the input array
 642     compile->node_arena()->Afree(_in,edge_size);
 643 
 644     // Free just the object
 645 #ifndef ASSERT
 646     compile->node_arena()->Afree(this,node_size);
 647 #endif
 648   }
 649   if (is_macro()) {
 650     compile->remove_macro_node(this);
 651   }
 652   if (is_expensive()) {
 653     compile->remove_expensive_node(this);
 654   }
 655   if (Opcode() == Op_Opaque4) {
 656     compile->remove_skeleton_predicate_opaq(this);
 657   }
 658   if (for_post_loop_opts_igvn()) {
 659     compile->remove_from_post_loop_opts_igvn(this);
 660   }
 661   if (is_InlineTypeBase()) {
 662     compile->remove_inline_type(this);
 663   }
 664 
 665   if (is_SafePoint()) {
 666     as_SafePoint()->delete_replaced_nodes();
 667 
 668     if (is_CallStaticJava()) {
 669       compile->remove_unstable_if_trap(as_CallStaticJava(), false);
 670     }
 671   }
 672   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 673   bs->unregister_potential_barrier_node(this);
 674 #ifdef ASSERT
 675   // We will not actually delete the storage, but we'll make the node unusable.
 676   *(address*)this = badAddress;  // smash the C++ vtbl, probably
 677   _in = _out = (Node**) badAddress;
 678   _max = _cnt = _outmax = _outcnt = 0;
 679   compile->remove_modified_node(this);
 680 #endif
 681 }
 682 
 683 //------------------------------grow-------------------------------------------
 684 // Grow the input array, making space for more edges
 685 void Node::grow(uint len) {
 686   Arena* arena = Compile::current()->node_arena();
 687   uint new_max = _max;
 688   if( new_max == 0 ) {
 689     _max = 4;
 690     _in = (Node**)arena->Amalloc(4*sizeof(Node*));
 691     Node** to = _in;
 692     to[0] = NULL;
 693     to[1] = NULL;
 694     to[2] = NULL;
 695     to[3] = NULL;
 696     return;
 697   }
 698   new_max = next_power_of_2(len);
 699   // Trimming to limit allows a uint8 to handle up to 255 edges.
 700   // Previously I was using only powers-of-2 which peaked at 128 edges.
 701   //if( new_max >= limit ) new_max = limit-1;
 702   _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
 703   Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
 704   _max = new_max;               // Record new max length
 705   // This assertion makes sure that Node::_max is wide enough to
 706   // represent the numerical value of new_max.
 707   assert(_max == new_max && _max > len, "int width of _max is too small");
 708 }
 709 
 710 //-----------------------------out_grow----------------------------------------
 711 // Grow the input array, making space for more edges
 712 void Node::out_grow( uint len ) {
 713   assert(!is_top(), "cannot grow a top node's out array");
 714   Arena* arena = Compile::current()->node_arena();
 715   uint new_max = _outmax;
 716   if( new_max == 0 ) {
 717     _outmax = 4;
 718     _out = (Node **)arena->Amalloc(4*sizeof(Node*));
 719     return;
 720   }
 721   new_max = next_power_of_2(len);
 722   // Trimming to limit allows a uint8 to handle up to 255 edges.
 723   // Previously I was using only powers-of-2 which peaked at 128 edges.
 724   //if( new_max >= limit ) new_max = limit-1;
 725   assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
 726   _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
 727   //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
 728   _outmax = new_max;               // Record new max length
 729   // This assertion makes sure that Node::_max is wide enough to
 730   // represent the numerical value of new_max.
 731   assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
 732 }
 733 
 734 #ifdef ASSERT
 735 //------------------------------is_dead----------------------------------------
 736 bool Node::is_dead() const {
 737   // Mach and pinch point nodes may look like dead.
 738   if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
 739     return false;
 740   for( uint i = 0; i < _max; i++ )
 741     if( _in[i] != NULL )
 742       return false;
 743   dump();
 744   return true;
 745 }
 746 
 747 bool Node::is_reachable_from_root() const {
 748   ResourceMark rm;
 749   Unique_Node_List wq;
 750   wq.push((Node*)this);
 751   RootNode* root = Compile::current()->root();
 752   for (uint i = 0; i < wq.size(); i++) {
 753     Node* m = wq.at(i);
 754     if (m == root) {
 755       return true;
 756     }
 757     for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
 758       Node* u = m->fast_out(j);
 759       wq.push(u);
 760     }
 761   }
 762   return false;
 763 }
 764 #endif
 765 
 766 //------------------------------is_unreachable---------------------------------
 767 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
 768   assert(!is_Mach(), "doesn't work with MachNodes");
 769   return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != NULL && in(0)->is_top());
 770 }
 771 
 772 //------------------------------add_req----------------------------------------
 773 // Add a new required input at the end
 774 void Node::add_req( Node *n ) {
 775   assert( is_not_dead(n), "can not use dead node");
 776 
 777   // Look to see if I can move precedence down one without reallocating
 778   if( (_cnt >= _max) || (in(_max-1) != NULL) )
 779     grow( _max+1 );
 780 
 781   // Find a precedence edge to move
 782   if( in(_cnt) != NULL ) {       // Next precedence edge is busy?
 783     uint i;
 784     for( i=_cnt; i<_max; i++ )
 785       if( in(i) == NULL )       // Find the NULL at end of prec edge list
 786         break;                  // There must be one, since we grew the array
 787     _in[i] = in(_cnt);          // Move prec over, making space for req edge
 788   }
 789   _in[_cnt++] = n;            // Stuff over old prec edge
 790   if (n != NULL) n->add_out((Node *)this);
 791   Compile::current()->record_modified_node(this);
 792 }
 793 
 794 //---------------------------add_req_batch-------------------------------------
 795 // Add a new required input at the end
 796 void Node::add_req_batch( Node *n, uint m ) {
 797   assert( is_not_dead(n), "can not use dead node");
 798   // check various edge cases
 799   if ((int)m <= 1) {
 800     assert((int)m >= 0, "oob");
 801     if (m != 0)  add_req(n);
 802     return;
 803   }
 804 
 805   // Look to see if I can move precedence down one without reallocating
 806   if( (_cnt+m) > _max || _in[_max-m] )
 807     grow( _max+m );
 808 
 809   // Find a precedence edge to move
 810   if( _in[_cnt] != NULL ) {     // Next precedence edge is busy?
 811     uint i;
 812     for( i=_cnt; i<_max; i++ )
 813       if( _in[i] == NULL )      // Find the NULL at end of prec edge list
 814         break;                  // There must be one, since we grew the array
 815     // Slide all the precs over by m positions (assume #prec << m).
 816     Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
 817   }
 818 
 819   // Stuff over the old prec edges
 820   for(uint i=0; i<m; i++ ) {
 821     _in[_cnt++] = n;
 822   }
 823 
 824   // Insert multiple out edges on the node.
 825   if (n != NULL && !n->is_top()) {
 826     for(uint i=0; i<m; i++ ) {
 827       n->add_out((Node *)this);
 828     }
 829   }
 830   Compile::current()->record_modified_node(this);
 831 }
 832 
 833 //------------------------------del_req----------------------------------------
 834 // Delete the required edge and compact the edge array
 835 void Node::del_req( uint idx ) {
 836   assert( idx < _cnt, "oob");
 837   assert( !VerifyHashTableKeys || _hash_lock == 0,
 838           "remove node from hash table before modifying it");
 839   // First remove corresponding def-use edge
 840   Node *n = in(idx);
 841   if (n != NULL) n->del_out((Node *)this);
 842   _in[idx] = in(--_cnt); // Compact the array
 843   // Avoid spec violation: Gap in prec edges.
 844   close_prec_gap_at(_cnt);
 845   Compile::current()->record_modified_node(this);
 846 }
 847 
 848 //------------------------------del_req_ordered--------------------------------
 849 // Delete the required edge and compact the edge array with preserved order
 850 void Node::del_req_ordered( uint idx ) {
 851   assert( idx < _cnt, "oob");
 852   assert( !VerifyHashTableKeys || _hash_lock == 0,
 853           "remove node from hash table before modifying it");
 854   // First remove corresponding def-use edge
 855   Node *n = in(idx);
 856   if (n != NULL) n->del_out((Node *)this);
 857   if (idx < --_cnt) {    // Not last edge ?
 858     Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
 859   }
 860   // Avoid spec violation: Gap in prec edges.
 861   close_prec_gap_at(_cnt);
 862   Compile::current()->record_modified_node(this);
 863 }
 864 
 865 //------------------------------ins_req----------------------------------------
 866 // Insert a new required input at the end
 867 void Node::ins_req( uint idx, Node *n ) {
 868   assert( is_not_dead(n), "can not use dead node");
 869   add_req(NULL);                // Make space
 870   assert( idx < _max, "Must have allocated enough space");
 871   // Slide over
 872   if(_cnt-idx-1 > 0) {
 873     Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
 874   }
 875   _in[idx] = n;                            // Stuff over old required edge
 876   if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
 877   Compile::current()->record_modified_node(this);
 878 }
 879 
 880 //-----------------------------find_edge---------------------------------------
 881 int Node::find_edge(Node* n) {
 882   for (uint i = 0; i < len(); i++) {
 883     if (_in[i] == n)  return i;
 884   }
 885   return -1;
 886 }
 887 
 888 //----------------------------replace_edge-------------------------------------
 889 int Node::replace_edge(Node* old, Node* neww, PhaseGVN* gvn) {
 890   if (old == neww)  return 0;  // nothing to do
 891   uint nrep = 0;
 892   for (uint i = 0; i < len(); i++) {
 893     if (in(i) == old) {
 894       if (i < req()) {
 895         if (gvn != NULL) {
 896           set_req_X(i, neww, gvn);
 897         } else {
 898           set_req(i, neww);
 899         }
 900       } else {
 901         assert(gvn == NULL || gvn->is_IterGVN() == NULL, "no support for igvn here");
 902         assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
 903         set_prec(i, neww);
 904       }
 905       nrep++;
 906     }
 907   }
 908   return nrep;
 909 }
 910 
 911 /**
 912  * Replace input edges in the range pointing to 'old' node.
 913  */
 914 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn) {
 915   if (old == neww)  return 0;  // nothing to do
 916   uint nrep = 0;
 917   for (int i = start; i < end; i++) {
 918     if (in(i) == old) {
 919       set_req_X(i, neww, gvn);
 920       nrep++;
 921     }
 922   }
 923   return nrep;
 924 }
 925 
 926 //-------------------------disconnect_inputs-----------------------------------
 927 // NULL out all inputs to eliminate incoming Def-Use edges.
 928 void Node::disconnect_inputs(Compile* C) {
 929   // the layout of Node::_in
 930   // r: a required input, null is allowed
 931   // p: a precedence, null values are all at the end
 932   // -----------------------------------
 933   // |r|...|r|p|...|p|null|...|null|
 934   //         |                     |
 935   //         req()                 len()
 936   // -----------------------------------
 937   for (uint i = 0; i < req(); ++i) {
 938     if (in(i) != nullptr) {
 939       set_req(i, nullptr);
 940     }
 941   }
 942 
 943   // Remove precedence edges if any exist
 944   // Note: Safepoints may have precedence edges, even during parsing
 945   for (uint i = len(); i > req(); ) {
 946     rm_prec(--i);  // no-op if _in[i] is nullptr
 947   }
 948 
 949 #ifdef ASSERT
 950   // sanity check
 951   for (uint i = 0; i < len(); ++i) {
 952     assert(_in[i] == nullptr, "disconnect_inputs() failed!");
 953   }
 954 #endif
 955 
 956   // Node::destruct requires all out edges be deleted first
 957   // debug_only(destruct();)   // no reuse benefit expected
 958   C->record_dead_node(_idx);
 959 }
 960 
 961 //-----------------------------uncast---------------------------------------
 962 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
 963 // Strip away casting.  (It is depth-limited.)
 964 // Optionally, keep casts with dependencies.
 965 Node* Node::uncast(bool keep_deps) const {
 966   // Should be inline:
 967   //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
 968   if (is_ConstraintCast()) {
 969     return uncast_helper(this, keep_deps);
 970   } else {
 971     return (Node*) this;
 972   }
 973 }
 974 
 975 // Find out of current node that matches opcode.
 976 Node* Node::find_out_with(int opcode) {
 977   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 978     Node* use = fast_out(i);
 979     if (use->Opcode() == opcode) {
 980       return use;
 981     }
 982   }
 983   return NULL;
 984 }
 985 
 986 // Return true if the current node has an out that matches opcode.
 987 bool Node::has_out_with(int opcode) {
 988   return (find_out_with(opcode) != NULL);
 989 }
 990 
 991 // Return true if the current node has an out that matches any of the opcodes.
 992 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
 993   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 994       int opcode = fast_out(i)->Opcode();
 995       if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
 996         return true;
 997       }
 998   }
 999   return false;
1000 }
1001 
1002 
1003 //---------------------------uncast_helper-------------------------------------
1004 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
1005 #ifdef ASSERT
1006   uint depth_count = 0;
1007   const Node* orig_p = p;
1008 #endif
1009 
1010   while (true) {
1011 #ifdef ASSERT
1012     if (depth_count >= K) {
1013       orig_p->dump(4);
1014       if (p != orig_p)
1015         p->dump(1);
1016     }
1017     assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
1018 #endif
1019     if (p == NULL || p->req() != 2) {
1020       break;
1021     } else if (p->is_ConstraintCast()) {
1022       if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
1023         break; // stop at casts with dependencies
1024       }
1025       p = p->in(1);
1026     } else {
1027       break;
1028     }
1029   }
1030   return (Node*) p;
1031 }
1032 
1033 //------------------------------add_prec---------------------------------------
1034 // Add a new precedence input.  Precedence inputs are unordered, with
1035 // duplicates removed and NULLs packed down at the end.
1036 void Node::add_prec( Node *n ) {
1037   assert( is_not_dead(n), "can not use dead node");
1038 
1039   // Check for NULL at end
1040   if( _cnt >= _max || in(_max-1) )
1041     grow( _max+1 );
1042 
1043   // Find a precedence edge to move
1044   uint i = _cnt;
1045   while( in(i) != NULL ) {
1046     if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1047     i++;
1048   }
1049   _in[i] = n;                                // Stuff prec edge over NULL
1050   if ( n != NULL) n->add_out((Node *)this);  // Add mirror edge
1051 
1052 #ifdef ASSERT
1053   while ((++i)<_max) { assert(_in[i] == NULL, "spec violation: Gap in prec edges (node %d)", _idx); }
1054 #endif
1055   Compile::current()->record_modified_node(this);
1056 }
1057 
1058 //------------------------------rm_prec----------------------------------------
1059 // Remove a precedence input.  Precedence inputs are unordered, with
1060 // duplicates removed and NULLs packed down at the end.
1061 void Node::rm_prec( uint j ) {
1062   assert(j < _max, "oob: i=%d, _max=%d", j, _max);
1063   assert(j >= _cnt, "not a precedence edge");
1064   if (_in[j] == NULL) return;   // Avoid spec violation: Gap in prec edges.
1065   _in[j]->del_out((Node *)this);
1066   close_prec_gap_at(j);
1067   Compile::current()->record_modified_node(this);
1068 }
1069 
1070 //------------------------------size_of----------------------------------------
1071 uint Node::size_of() const { return sizeof(*this); }
1072 
1073 //------------------------------ideal_reg--------------------------------------
1074 uint Node::ideal_reg() const { return 0; }
1075 
1076 //------------------------------jvms-------------------------------------------
1077 JVMState* Node::jvms() const { return NULL; }
1078 
1079 #ifdef ASSERT
1080 //------------------------------jvms-------------------------------------------
1081 bool Node::verify_jvms(const JVMState* using_jvms) const {
1082   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1083     if (jvms == using_jvms)  return true;
1084   }
1085   return false;
1086 }
1087 
1088 //------------------------------init_NodeProperty------------------------------
1089 void Node::init_NodeProperty() {
1090   assert(_max_classes <= max_juint, "too many NodeProperty classes");
1091   assert(max_flags() <= max_juint, "too many NodeProperty flags");
1092 }
1093 
1094 //-----------------------------max_flags---------------------------------------
1095 juint Node::max_flags() {
1096   return (PD::_last_flag << 1) - 1; // allow flags combination
1097 }
1098 #endif
1099 
1100 //------------------------------format-----------------------------------------
1101 // Print as assembly
1102 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1103 //------------------------------emit-------------------------------------------
1104 // Emit bytes starting at parameter 'ptr'.
1105 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1106 //------------------------------size-------------------------------------------
1107 // Size of instruction in bytes
1108 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1109 
1110 //------------------------------CFG Construction-------------------------------
1111 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1112 // Goto and Return.
1113 const Node *Node::is_block_proj() const { return 0; }
1114 
1115 // Minimum guaranteed type
1116 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1117 
1118 
1119 //------------------------------raise_bottom_type------------------------------
1120 // Get the worst-case Type output for this Node.
1121 void Node::raise_bottom_type(const Type* new_type) {
1122   if (is_Type()) {
1123     TypeNode *n = this->as_Type();
1124     if (VerifyAliases) {
1125       assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1126     }
1127     n->set_type(new_type);
1128   } else if (is_Load()) {
1129     LoadNode *n = this->as_Load();
1130     if (VerifyAliases) {
1131       assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1132     }
1133     n->set_type(new_type);
1134   }
1135 }
1136 
1137 //------------------------------Identity---------------------------------------
1138 // Return a node that the given node is equivalent to.
1139 Node* Node::Identity(PhaseGVN* phase) {
1140   return this;                  // Default to no identities
1141 }
1142 
1143 //------------------------------Value------------------------------------------
1144 // Compute a new Type for a node using the Type of the inputs.
1145 const Type* Node::Value(PhaseGVN* phase) const {
1146   return bottom_type();         // Default to worst-case Type
1147 }
1148 
1149 //------------------------------Ideal------------------------------------------
1150 //
1151 // 'Idealize' the graph rooted at this Node.
1152 //
1153 // In order to be efficient and flexible there are some subtle invariants
1154 // these Ideal calls need to hold.  Running with '+VerifyIterativeGVN' checks
1155 // these invariants, although its too slow to have on by default.  If you are
1156 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1157 //
1158 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1159 // pointer.  If ANY change is made, it must return the root of the reshaped
1160 // graph - even if the root is the same Node.  Example: swapping the inputs
1161 // to an AddINode gives the same answer and same root, but you still have to
1162 // return the 'this' pointer instead of NULL.
1163 //
1164 // You cannot return an OLD Node, except for the 'this' pointer.  Use the
1165 // Identity call to return an old Node; basically if Identity can find
1166 // another Node have the Ideal call make no change and return NULL.
1167 // Example: AddINode::Ideal must check for add of zero; in this case it
1168 // returns NULL instead of doing any graph reshaping.
1169 //
1170 // You cannot modify any old Nodes except for the 'this' pointer.  Due to
1171 // sharing there may be other users of the old Nodes relying on their current
1172 // semantics.  Modifying them will break the other users.
1173 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1174 // "X+3" unchanged in case it is shared.
1175 //
1176 // If you modify the 'this' pointer's inputs, you should use
1177 // 'set_req'.  If you are making a new Node (either as the new root or
1178 // some new internal piece) you may use 'init_req' to set the initial
1179 // value.  You can make a new Node with either 'new' or 'clone'.  In
1180 // either case, def-use info is correctly maintained.
1181 //
1182 // Example: reshape "(X+3)+4" into "X+7":
1183 //    set_req(1, in(1)->in(1));
1184 //    set_req(2, phase->intcon(7));
1185 //    return this;
1186 // Example: reshape "X*4" into "X<<2"
1187 //    return new LShiftINode(in(1), phase->intcon(2));
1188 //
1189 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1190 // for the returned root node.  Example: reshape "X*31" with "(X<<5)-X".
1191 //    Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1192 //    return new AddINode(shift, in(1));
1193 //
1194 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1195 // These forms are faster than 'phase->transform(new ConNode())' and Do
1196 // The Right Thing with def-use info.
1197 //
1198 // You cannot bury the 'this' Node inside of a graph reshape.  If the reshaped
1199 // graph uses the 'this' Node it must be the root.  If you want a Node with
1200 // the same Opcode as the 'this' pointer use 'clone'.
1201 //
1202 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1203   return NULL;                  // Default to being Ideal already
1204 }
1205 
1206 // Some nodes have specific Ideal subgraph transformations only if they are
1207 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1208 // for the transformations to happen.
1209 bool Node::has_special_unique_user() const {
1210   assert(outcnt() == 1, "match only for unique out");
1211   Node* n = unique_out();
1212   int op  = Opcode();
1213   if (this->is_Store()) {
1214     // Condition for back-to-back stores folding.
1215     return n->Opcode() == op && n->in(MemNode::Memory) == this;
1216   } else if (this->is_Load() || this->is_DecodeN() || this->is_Phi()) {
1217     // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1218     return n->Opcode() == Op_MemBarAcquire;
1219   } else if (op == Op_AddL) {
1220     // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1221     return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1222   } else if (op == Op_SubI || op == Op_SubL) {
1223     // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1224     return n->Opcode() == op && n->in(2) == this;
1225   } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1226     // See IfProjNode::Identity()
1227     return true;
1228   } else if ((is_IfFalse() || is_IfTrue()) && n->is_If()) {
1229     // See IfNode::fold_compares
1230     return true;
1231   } else {
1232     return false;
1233   }
1234 };
1235 
1236 //--------------------------find_exact_control---------------------------------
1237 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1238 Node* Node::find_exact_control(Node* ctrl) {
1239   if (ctrl == NULL && this->is_Region())
1240     ctrl = this->as_Region()->is_copy();
1241 
1242   if (ctrl != NULL && ctrl->is_CatchProj()) {
1243     if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1244       ctrl = ctrl->in(0);
1245     if (ctrl != NULL && !ctrl->is_top())
1246       ctrl = ctrl->in(0);
1247   }
1248 
1249   if (ctrl != NULL && ctrl->is_Proj())
1250     ctrl = ctrl->in(0);
1251 
1252   return ctrl;
1253 }
1254 
1255 //--------------------------dominates------------------------------------------
1256 // Helper function for MemNode::all_controls_dominate().
1257 // Check if 'this' control node dominates or equal to 'sub' control node.
1258 // We already know that if any path back to Root or Start reaches 'this',
1259 // then all paths so, so this is a simple search for one example,
1260 // not an exhaustive search for a counterexample.
1261 bool Node::dominates(Node* sub, Node_List &nlist) {
1262   assert(this->is_CFG(), "expecting control");
1263   assert(sub != NULL && sub->is_CFG(), "expecting control");
1264 
1265   // detect dead cycle without regions
1266   int iterations_without_region_limit = DominatorSearchLimit;
1267 
1268   Node* orig_sub = sub;
1269   Node* dom      = this;
1270   bool  met_dom  = false;
1271   nlist.clear();
1272 
1273   // Walk 'sub' backward up the chain to 'dom', watching for regions.
1274   // After seeing 'dom', continue up to Root or Start.
1275   // If we hit a region (backward split point), it may be a loop head.
1276   // Keep going through one of the region's inputs.  If we reach the
1277   // same region again, go through a different input.  Eventually we
1278   // will either exit through the loop head, or give up.
1279   // (If we get confused, break out and return a conservative 'false'.)
1280   while (sub != NULL) {
1281     if (sub->is_top())  break; // Conservative answer for dead code.
1282     if (sub == dom) {
1283       if (nlist.size() == 0) {
1284         // No Region nodes except loops were visited before and the EntryControl
1285         // path was taken for loops: it did not walk in a cycle.
1286         return true;
1287       } else if (met_dom) {
1288         break;          // already met before: walk in a cycle
1289       } else {
1290         // Region nodes were visited. Continue walk up to Start or Root
1291         // to make sure that it did not walk in a cycle.
1292         met_dom = true; // first time meet
1293         iterations_without_region_limit = DominatorSearchLimit; // Reset
1294      }
1295     }
1296     if (sub->is_Start() || sub->is_Root()) {
1297       // Success if we met 'dom' along a path to Start or Root.
1298       // We assume there are no alternative paths that avoid 'dom'.
1299       // (This assumption is up to the caller to ensure!)
1300       return met_dom;
1301     }
1302     Node* up = sub->in(0);
1303     // Normalize simple pass-through regions and projections:
1304     up = sub->find_exact_control(up);
1305     // If sub == up, we found a self-loop.  Try to push past it.
1306     if (sub == up && sub->is_Loop()) {
1307       // Take loop entry path on the way up to 'dom'.
1308       up = sub->in(1); // in(LoopNode::EntryControl);
1309     } else if (sub == up && sub->is_Region() && sub->req() == 2) {
1310       // Take in(1) path on the way up to 'dom' for regions with only one input
1311       up = sub->in(1);
1312     } else if (sub == up && sub->is_Region() && sub->req() == 3) {
1313       // Try both paths for Regions with 2 input paths (it may be a loop head).
1314       // It could give conservative 'false' answer without information
1315       // which region's input is the entry path.
1316       iterations_without_region_limit = DominatorSearchLimit; // Reset
1317 
1318       bool region_was_visited_before = false;
1319       // Was this Region node visited before?
1320       // If so, we have reached it because we accidentally took a
1321       // loop-back edge from 'sub' back into the body of the loop,
1322       // and worked our way up again to the loop header 'sub'.
1323       // So, take the first unexplored path on the way up to 'dom'.
1324       for (int j = nlist.size() - 1; j >= 0; j--) {
1325         intptr_t ni = (intptr_t)nlist.at(j);
1326         Node* visited = (Node*)(ni & ~1);
1327         bool  visited_twice_already = ((ni & 1) != 0);
1328         if (visited == sub) {
1329           if (visited_twice_already) {
1330             // Visited 2 paths, but still stuck in loop body.  Give up.
1331             return false;
1332           }
1333           // The Region node was visited before only once.
1334           // (We will repush with the low bit set, below.)
1335           nlist.remove(j);
1336           // We will find a new edge and re-insert.
1337           region_was_visited_before = true;
1338           break;
1339         }
1340       }
1341 
1342       // Find an incoming edge which has not been seen yet; walk through it.
1343       assert(up == sub, "");
1344       uint skip = region_was_visited_before ? 1 : 0;
1345       for (uint i = 1; i < sub->req(); i++) {
1346         Node* in = sub->in(i);
1347         if (in != NULL && !in->is_top() && in != sub) {
1348           if (skip == 0) {
1349             up = in;
1350             break;
1351           }
1352           --skip;               // skip this nontrivial input
1353         }
1354       }
1355 
1356       // Set 0 bit to indicate that both paths were taken.
1357       nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1358     }
1359 
1360     if (up == sub) {
1361       break;    // some kind of tight cycle
1362     }
1363     if (up == orig_sub && met_dom) {
1364       // returned back after visiting 'dom'
1365       break;    // some kind of cycle
1366     }
1367     if (--iterations_without_region_limit < 0) {
1368       break;    // dead cycle
1369     }
1370     sub = up;
1371   }
1372 
1373   // Did not meet Root or Start node in pred. chain.
1374   // Conservative answer for dead code.
1375   return false;
1376 }
1377 
1378 //------------------------------remove_dead_region-----------------------------
1379 // This control node is dead.  Follow the subgraph below it making everything
1380 // using it dead as well.  This will happen normally via the usual IterGVN
1381 // worklist but this call is more efficient.  Do not update use-def info
1382 // inside the dead region, just at the borders.
1383 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1384   // Con's are a popular node to re-hit in the hash table again.
1385   if( dead->is_Con() ) return;
1386 
1387   ResourceMark rm;
1388   Node_List nstack;
1389 
1390   Node *top = igvn->C->top();
1391   nstack.push(dead);
1392   bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1393 
1394   while (nstack.size() > 0) {
1395     dead = nstack.pop();
1396     if (dead->Opcode() == Op_SafePoint) {
1397       dead->as_SafePoint()->disconnect_from_root(igvn);
1398     }
1399     if (dead->outcnt() > 0) {
1400       // Keep dead node on stack until all uses are processed.
1401       nstack.push(dead);
1402       // For all Users of the Dead...    ;-)
1403       for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1404         Node* use = dead->last_out(k);
1405         igvn->hash_delete(use);       // Yank from hash table prior to mod
1406         if (use->in(0) == dead) {     // Found another dead node
1407           assert (!use->is_Con(), "Control for Con node should be Root node.");
1408           use->set_req(0, top);       // Cut dead edge to prevent processing
1409           nstack.push(use);           // the dead node again.
1410         } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1411                    use->is_Loop() && !use->is_Root() &&       // Don't kill Root (RootNode extends LoopNode)
1412                    use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1413           use->set_req(LoopNode::EntryControl, top);          // Cut dead edge to prevent processing
1414           use->set_req(0, top);       // Cut self edge
1415           nstack.push(use);
1416         } else {                      // Else found a not-dead user
1417           // Dead if all inputs are top or null
1418           bool dead_use = !use->is_Root(); // Keep empty graph alive
1419           for (uint j = 1; j < use->req(); j++) {
1420             Node* in = use->in(j);
1421             if (in == dead) {         // Turn all dead inputs into TOP
1422               use->set_req(j, top);
1423             } else if (in != NULL && !in->is_top()) {
1424               dead_use = false;
1425             }
1426           }
1427           if (dead_use) {
1428             if (use->is_Region()) {
1429               use->set_req(0, top);   // Cut self edge
1430             }
1431             nstack.push(use);
1432           } else {
1433             igvn->_worklist.push(use);
1434           }
1435         }
1436         // Refresh the iterator, since any number of kills might have happened.
1437         k = dead->last_outs(kmin);
1438       }
1439     } else { // (dead->outcnt() == 0)
1440       // Done with outputs.
1441       igvn->hash_delete(dead);
1442       igvn->_worklist.remove(dead);
1443       igvn->set_type(dead, Type::TOP);
1444       // Kill all inputs to the dead guy
1445       for (uint i=0; i < dead->req(); i++) {
1446         Node *n = dead->in(i);      // Get input to dead guy
1447         if (n != NULL && !n->is_top()) { // Input is valid?
1448           dead->set_req(i, top);    // Smash input away
1449           if (n->outcnt() == 0) {   // Input also goes dead?
1450             if (!n->is_Con())
1451               nstack.push(n);       // Clear it out as well
1452           } else if (n->outcnt() == 1 &&
1453                      n->has_special_unique_user()) {
1454             igvn->add_users_to_worklist( n );
1455           } else if (n->outcnt() <= 2 && n->is_Store()) {
1456             // Push store's uses on worklist to enable folding optimization for
1457             // store/store and store/load to the same address.
1458             // The restriction (outcnt() <= 2) is the same as in set_req_X()
1459             // and remove_globally_dead_node().
1460             igvn->add_users_to_worklist( n );
1461           } else {
1462             BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1463           }
1464         }
1465       }
1466       igvn->C->remove_useless_node(dead);
1467     } // (dead->outcnt() == 0)
1468   }   // while (nstack.size() > 0) for outputs
1469   return;
1470 }
1471 
1472 //------------------------------remove_dead_region-----------------------------
1473 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1474   Node *n = in(0);
1475   if( !n ) return false;
1476   // Lost control into this guy?  I.e., it became unreachable?
1477   // Aggressively kill all unreachable code.
1478   if (can_reshape && n->is_top()) {
1479     kill_dead_code(this, phase->is_IterGVN());
1480     return false; // Node is dead.
1481   }
1482 
1483   if( n->is_Region() && n->as_Region()->is_copy() ) {
1484     Node *m = n->nonnull_req();
1485     set_req(0, m);
1486     return true;
1487   }
1488   return false;
1489 }
1490 
1491 //------------------------------hash-------------------------------------------
1492 // Hash function over Nodes.
1493 uint Node::hash() const {
1494   uint sum = 0;
1495   for( uint i=0; i<_cnt; i++ )  // Add in all inputs
1496     sum = (sum<<1)-(uintptr_t)in(i);        // Ignore embedded NULLs
1497   return (sum>>2) + _cnt + Opcode();
1498 }
1499 
1500 //------------------------------cmp--------------------------------------------
1501 // Compare special parts of simple Nodes
1502 bool Node::cmp( const Node &n ) const {
1503   return true;                  // Must be same
1504 }
1505 
1506 //------------------------------rematerialize-----------------------------------
1507 // Should we clone rather than spill this instruction?
1508 bool Node::rematerialize() const {
1509   if ( is_Mach() )
1510     return this->as_Mach()->rematerialize();
1511   else
1512     return (_flags & Flag_rematerialize) != 0;
1513 }
1514 
1515 //------------------------------needs_anti_dependence_check---------------------
1516 // Nodes which use memory without consuming it, hence need antidependences.
1517 bool Node::needs_anti_dependence_check() const {
1518   if (req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0) {
1519     return false;
1520   }
1521   return in(1)->bottom_type()->has_memory();
1522 }
1523 
1524 // Get an integer constant from a ConNode (or CastIINode).
1525 // Return a default value if there is no apparent constant here.
1526 const TypeInt* Node::find_int_type() const {
1527   if (this->is_Type()) {
1528     return this->as_Type()->type()->isa_int();
1529   } else if (this->is_Con()) {
1530     assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1531     return this->bottom_type()->isa_int();
1532   }
1533   return NULL;
1534 }
1535 
1536 const TypeInteger* Node::find_integer_type(BasicType bt) const {
1537   if (this->is_Type()) {
1538     return this->as_Type()->type()->isa_integer(bt);
1539   } else if (this->is_Con()) {
1540     assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1541     return this->bottom_type()->isa_integer(bt);
1542   }
1543   return NULL;
1544 }
1545 
1546 // Get a pointer constant from a ConstNode.
1547 // Returns the constant if it is a pointer ConstNode
1548 intptr_t Node::get_ptr() const {
1549   assert( Opcode() == Op_ConP, "" );
1550   return ((ConPNode*)this)->type()->is_ptr()->get_con();
1551 }
1552 
1553 // Get a narrow oop constant from a ConNNode.
1554 intptr_t Node::get_narrowcon() const {
1555   assert( Opcode() == Op_ConN, "" );
1556   return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1557 }
1558 
1559 // Get a long constant from a ConNode.
1560 // Return a default value if there is no apparent constant here.
1561 const TypeLong* Node::find_long_type() const {
1562   if (this->is_Type()) {
1563     return this->as_Type()->type()->isa_long();
1564   } else if (this->is_Con()) {
1565     assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1566     return this->bottom_type()->isa_long();
1567   }
1568   return NULL;
1569 }
1570 
1571 
1572 /**
1573  * Return a ptr type for nodes which should have it.
1574  */
1575 const TypePtr* Node::get_ptr_type() const {
1576   const TypePtr* tp = this->bottom_type()->make_ptr();
1577 #ifdef ASSERT
1578   if (tp == NULL) {
1579     this->dump(1);
1580     assert((tp != NULL), "unexpected node type");
1581   }
1582 #endif
1583   return tp;
1584 }
1585 
1586 // Get a double constant from a ConstNode.
1587 // Returns the constant if it is a double ConstNode
1588 jdouble Node::getd() const {
1589   assert( Opcode() == Op_ConD, "" );
1590   return ((ConDNode*)this)->type()->is_double_constant()->getd();
1591 }
1592 
1593 // Get a float constant from a ConstNode.
1594 // Returns the constant if it is a float ConstNode
1595 jfloat Node::getf() const {
1596   assert( Opcode() == Op_ConF, "" );
1597   return ((ConFNode*)this)->type()->is_float_constant()->getf();
1598 }
1599 
1600 #ifndef PRODUCT
1601 
1602 // Call this from debugger:
1603 Node* old_root() {
1604   Matcher* matcher = Compile::current()->matcher();
1605   if (matcher != nullptr) {
1606     Node* new_root = Compile::current()->root();
1607     Node* old_root = matcher->find_old_node(new_root);
1608     if (old_root != nullptr) {
1609       return old_root;
1610     }
1611   }
1612   tty->print("old_root: not found.\n");
1613   return nullptr;
1614 }
1615 
1616 // BFS traverse all reachable nodes from start, call callback on them
1617 template <typename Callback>
1618 void visit_nodes(Node* start, Callback callback, bool traverse_output, bool only_ctrl) {
1619   Unique_Mixed_Node_List worklist;
1620   worklist.add(start);
1621   for (uint i = 0; i < worklist.size(); i++) {
1622     Node* n = worklist[i];
1623     callback(n);
1624     for (uint i = 0; i < n->len(); i++) {
1625       if (!only_ctrl || n->is_Region() || (n->Opcode() == Op_Root) || (i == TypeFunc::Control)) {
1626         // If only_ctrl is set: Add regions, the root node, or control inputs only
1627         worklist.add(n->in(i));
1628       }
1629     }
1630     if (traverse_output && !only_ctrl) {
1631       for (uint i = 0; i < n->outcnt(); i++) {
1632         worklist.add(n->raw_out(i));
1633       }
1634     }
1635   }
1636 }
1637 
1638 // BFS traverse from start, return node with idx
1639 Node* find_node_by_idx(Node* start, uint idx, bool traverse_output, bool only_ctrl) {
1640   ResourceMark rm;
1641   Node* result = nullptr;
1642   auto callback = [&] (Node* n) {
1643     if (n->_idx == idx) {
1644       if (result != nullptr) {
1645         tty->print("find_node_by_idx: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1646           (uintptr_t)result, (uintptr_t)n, idx);
1647       }
1648       result = n;
1649     }
1650   };
1651   visit_nodes(start, callback, traverse_output, only_ctrl);
1652   return result;
1653 }
1654 
1655 int node_idx_cmp(const Node** n1, const Node** n2) {
1656   return (*n1)->_idx - (*n2)->_idx;
1657 }
1658 
1659 void find_nodes_by_name(Node* start, const char* name) {
1660   ResourceMark rm;
1661   GrowableArray<const Node*> ns;
1662   auto callback = [&] (const Node* n) {
1663     if (StringUtils::is_star_match(name, n->Name())) {
1664       ns.push(n);
1665     }
1666   };
1667   visit_nodes(start, callback, true, false);
1668   ns.sort(node_idx_cmp);
1669   for (int i = 0; i < ns.length(); i++) {
1670     ns.at(i)->dump();
1671   }
1672 }
1673 
1674 void find_nodes_by_dump(Node* start, const char* pattern) {
1675   ResourceMark rm;
1676   GrowableArray<const Node*> ns;
1677   auto callback = [&] (const Node* n) {
1678     stringStream stream;
1679     n->dump("", false, &stream);
1680     if (StringUtils::is_star_match(pattern, stream.base())) {
1681       ns.push(n);
1682     }
1683   };
1684   visit_nodes(start, callback, true, false);
1685   ns.sort(node_idx_cmp);
1686   for (int i = 0; i < ns.length(); i++) {
1687     ns.at(i)->dump();
1688   }
1689 }
1690 
1691 // call from debugger: find node with name pattern in new/current graph
1692 // name can contain "*" in match pattern to match any characters
1693 // the matching is case insensitive
1694 void find_nodes_by_name(const char* name) {
1695   Node* root = Compile::current()->root();
1696   find_nodes_by_name(root, name);
1697 }
1698 
1699 // call from debugger: find node with name pattern in old graph
1700 // name can contain "*" in match pattern to match any characters
1701 // the matching is case insensitive
1702 void find_old_nodes_by_name(const char* name) {
1703   Node* root = old_root();
1704   find_nodes_by_name(root, name);
1705 }
1706 
1707 // call from debugger: find node with dump pattern in new/current graph
1708 // can contain "*" in match pattern to match any characters
1709 // the matching is case insensitive
1710 void find_nodes_by_dump(const char* pattern) {
1711   Node* root = Compile::current()->root();
1712   find_nodes_by_dump(root, pattern);
1713 }
1714 
1715 // call from debugger: find node with name pattern in old graph
1716 // can contain "*" in match pattern to match any characters
1717 // the matching is case insensitive
1718 void find_old_nodes_by_dump(const char* pattern) {
1719   Node* root = old_root();
1720   find_nodes_by_dump(root, pattern);
1721 }
1722 
1723 // Call this from debugger, search in same graph as n:
1724 Node* find_node(Node* n, const int idx) {
1725   return n->find(idx);
1726 }
1727 
1728 // Call this from debugger, search in new nodes:
1729 Node* find_node(const int idx) {
1730   return Compile::current()->root()->find(idx);
1731 }
1732 
1733 // Call this from debugger, search in old nodes:
1734 Node* find_old_node(const int idx) {
1735   Node* root = old_root();
1736   return (root == nullptr) ? nullptr : root->find(idx);
1737 }
1738 
1739 // Call this from debugger, search in same graph as n:
1740 Node* find_ctrl(Node* n, const int idx) {
1741   return n->find_ctrl(idx);
1742 }
1743 
1744 // Call this from debugger, search in new nodes:
1745 Node* find_ctrl(const int idx) {
1746   return Compile::current()->root()->find_ctrl(idx);
1747 }
1748 
1749 // Call this from debugger, search in old nodes:
1750 Node* find_old_ctrl(const int idx) {
1751   Node* root = old_root();
1752   return (root == nullptr) ? nullptr : root->find_ctrl(idx);
1753 }
1754 
1755 //------------------------------find_ctrl--------------------------------------
1756 // Find an ancestor to this node in the control history with given _idx
1757 Node* Node::find_ctrl(int idx) {
1758   return find(idx, true);
1759 }
1760 
1761 //------------------------------find-------------------------------------------
1762 // Tries to find the node with the index |idx| starting from this node. If idx is negative,
1763 // the search also includes forward (out) edges. Returns NULL if not found.
1764 // If only_ctrl is set, the search will only be done on control nodes. Returns NULL if
1765 // not found or if the node to be found is not a control node (search will not find it).
1766 Node* Node::find(const int idx, bool only_ctrl) {
1767   ResourceMark rm;
1768   return find_node_by_idx(this, abs(idx), (idx < 0), only_ctrl);
1769 }
1770 
1771 class PrintBFS {
1772 public:
1773   PrintBFS(const Node* start, const int max_distance, const Node* target, const char* options)
1774   : _start(start), _max_distance(max_distance), _target(target), _options(options),
1775     _dcc(this), _info_uid(cmpkey, hashkey) {}
1776 
1777   void run();
1778 private:
1779   // pipeline steps
1780   bool configure();
1781   void collect();
1782   void select();
1783   void select_all();
1784   void select_all_paths();
1785   void select_shortest_path();
1786   void sort();
1787   void print();
1788 
1789   // inputs
1790   const Node* _start;
1791   const int _max_distance;
1792   const Node* _target;
1793   const char* _options;
1794 
1795   // options
1796   bool _traverse_inputs = false;
1797   bool _traverse_outputs = false;
1798   struct Filter {
1799     bool _control = false;
1800     bool _memory = false;
1801     bool _data = false;
1802     bool _mixed = false;
1803     bool _other = false;
1804     bool is_empty() const {
1805       return !(_control || _memory || _data || _mixed || _other);
1806     }
1807     void set_all() {
1808       _control = true;
1809       _memory = true;
1810       _data = true;
1811       _mixed = true;
1812       _other = true;
1813     }
1814     // Check if the filter accepts the node. Go by the type categories, but also all CFG nodes
1815     // are considered to have control.
1816     bool accepts(const Node* n) {
1817       const Type* t = n->bottom_type();
1818       return ( _data    &&  t->has_category(Type::Category::Data)                    ) ||
1819              ( _memory  &&  t->has_category(Type::Category::Memory)                  ) ||
1820              ( _mixed   &&  t->has_category(Type::Category::Mixed)                   ) ||
1821              ( _control && (t->has_category(Type::Category::Control) || n->is_CFG()) ) ||
1822              ( _other   &&  t->has_category(Type::Category::Other)                   );
1823     }
1824   };
1825   Filter _filter_visit;
1826   Filter _filter_boundary;
1827   bool _sort_idx = false;
1828   bool _all_paths = false;
1829   bool _use_color = false;
1830   bool _print_blocks = false;
1831   bool _print_old = false;
1832   bool _dump_only = false;
1833   static void print_options_help(bool print_examples);
1834   bool parse_options();
1835 
1836 public:
1837   class DumpConfigColored : public Node::DumpConfig {
1838   public:
1839     DumpConfigColored(PrintBFS* bfs) : _bfs(bfs) {};
1840     virtual void pre_dump(outputStream* st, const Node* n);
1841     virtual void post_dump(outputStream* st);
1842   private:
1843     PrintBFS* _bfs;
1844   };
1845 private:
1846   DumpConfigColored _dcc;
1847 
1848   // node info
1849   static Node* old_node(const Node* n); // mach node -> prior IR node
1850   static void print_node_idx(const Node* n); // to tty
1851   static void print_block_id(const Block* b); // to tty
1852   static void print_node_block(const Node* n); // to tty: _pre_order, head idx, _idom, _dom_depth
1853 
1854   // traversal data structures
1855   GrowableArray<const Node*> _worklist; // BFS queue
1856   void maybe_traverse(const Node* src, const Node* dst);
1857 
1858   // node info annotation
1859   class Info {
1860   public:
1861     Info() : Info(nullptr, 0) {};
1862     Info(const Node* node, int distance)
1863       : _node(node), _distance_from_start(distance) {};
1864     const Node* node() const { return _node; };
1865     int distance() const { return _distance_from_start; };
1866     int distance_from_target() const { return _distance_from_target; }
1867     void set_distance_from_target(int d) { _distance_from_target = d; }
1868     GrowableArray<const Node*> edge_bwd; // pointing toward _start
1869     bool is_marked() const { return _mark; } // marked to keep during select
1870     void set_mark() { _mark = true; }
1871   private:
1872     const Node* _node;
1873     int _distance_from_start; // distance from _start
1874     int _distance_from_target = 0; // distance from _target if _all_paths
1875     bool _mark = false;
1876   };
1877   Dict _info_uid;            // Node -> uid
1878   GrowableArray<Info> _info; // uid  -> info
1879 
1880   Info* find_info(const Node* n) {
1881     size_t uid = (size_t)_info_uid[n];
1882     if (uid == 0) {
1883       return nullptr;
1884     }
1885     return &_info.at((int)uid);
1886   }
1887 
1888   void make_info(const Node* node, const int distance) {
1889     assert(find_info(node) == nullptr, "node does not yet have info");
1890     size_t uid = _info.length() + 1;
1891     _info_uid.Insert((void*)node, (void*)uid);
1892     _info.at_put_grow((int)uid, Info(node, distance));
1893     assert(find_info(node)->node() == node, "stored correct node");
1894   };
1895 
1896   // filled by sort, printed by print
1897   GrowableArray<const Node*> _print_list;
1898 
1899   // print header + node table
1900   void print_header() const;
1901   void print_node(const Node* n);
1902 };
1903 
1904 void PrintBFS::run() {
1905   if (!configure()) {
1906     return;
1907   }
1908   collect();
1909   select();
1910   sort();
1911   print();
1912 }
1913 
1914 // set up configuration for BFS and print
1915 bool PrintBFS::configure() {
1916   if (_max_distance < 0) {
1917     tty->print("dump_bfs: max_distance must be non-negative!\n");
1918     return false;
1919   }
1920   return parse_options();
1921 }
1922 
1923 // BFS traverse according to configuration, fill worklist and info
1924 void PrintBFS::collect() {
1925   maybe_traverse(_start, _start);
1926   int pos = 0;
1927   while (pos < _worklist.length()) {
1928     const Node* n = _worklist.at(pos++); // next node to traverse
1929     Info* info = find_info(n);
1930     if (!_filter_visit.accepts(n) && n != _start) {
1931       continue; // we hit boundary, do not traverse further
1932     }
1933     if (n != _start && n->is_Root()) {
1934       continue; // traversing through root node would lead to unrelated nodes
1935     }
1936     if (_traverse_inputs && _max_distance > info->distance()) {
1937       for (uint i = 0; i < n->req(); i++) {
1938         maybe_traverse(n, n->in(i));
1939       }
1940     }
1941     if (_traverse_outputs && _max_distance > info->distance()) {
1942       for (uint i = 0; i < n->outcnt(); i++) {
1943         maybe_traverse(n, n->raw_out(i));
1944       }
1945     }
1946   }
1947 }
1948 
1949 // go through work list, mark those that we want to print
1950 void PrintBFS::select() {
1951   if (_target == nullptr ) {
1952     select_all();
1953   } else {
1954     if (find_info(_target) == nullptr) {
1955       tty->print("Could not find target in BFS.\n");
1956       return;
1957     }
1958     if (_all_paths) {
1959       select_all_paths();
1960     } else {
1961       select_shortest_path();
1962     }
1963   }
1964 }
1965 
1966 // take all nodes from BFS
1967 void PrintBFS::select_all() {
1968   for (int i = 0; i < _worklist.length(); i++) {
1969     const Node* n = _worklist.at(i);
1970     Info* info = find_info(n);
1971     info->set_mark();
1972   }
1973 }
1974 
1975 // traverse backward from target, along edges found in BFS
1976 void PrintBFS::select_all_paths() {
1977   int pos = 0;
1978   GrowableArray<const Node*> backtrace;
1979   // start from target
1980   backtrace.push(_target);
1981   find_info(_target)->set_mark();
1982   // traverse backward
1983   while (pos < backtrace.length()) {
1984     const Node* n = backtrace.at(pos++);
1985     Info* info = find_info(n);
1986     for (int i = 0; i < info->edge_bwd.length(); i++) {
1987       // all backward edges
1988       const Node* back = info->edge_bwd.at(i);
1989       Info* back_info = find_info(back);
1990       if (!back_info->is_marked()) {
1991         // not yet found this on way back.
1992         back_info->set_distance_from_target(info->distance_from_target() + 1);
1993         if (back_info->distance_from_target() + back_info->distance() <= _max_distance) {
1994           // total distance is small enough
1995           back_info->set_mark();
1996           backtrace.push(back);
1997         }
1998       }
1999     }
2000   }
2001 }
2002 
2003 void PrintBFS::select_shortest_path() {
2004   const Node* current = _target;
2005   while (true) {
2006     Info* info = find_info(current);
2007     info->set_mark();
2008     if (current == _start) {
2009       break;
2010     }
2011     // first edge -> leads us one step closer to _start
2012     current = info->edge_bwd.at(0);
2013   }
2014 }
2015 
2016 // go through worklist in desired order, put the marked ones in print list
2017 void PrintBFS::sort() {
2018   if (_traverse_inputs && !_traverse_outputs) {
2019     // reverse order
2020     for (int i = _worklist.length() - 1; i >= 0; i--) {
2021       const Node* n = _worklist.at(i);
2022       Info* info = find_info(n);
2023       if (info->is_marked()) {
2024         _print_list.push(n);
2025       }
2026     }
2027   } else {
2028     // same order as worklist
2029     for (int i = 0; i < _worklist.length(); i++) {
2030       const Node* n = _worklist.at(i);
2031       Info* info = find_info(n);
2032       if (info->is_marked()) {
2033         _print_list.push(n);
2034       }
2035     }
2036   }
2037   if (_sort_idx) {
2038     _print_list.sort(node_idx_cmp);
2039   }
2040 }
2041 
2042 // go through printlist and print
2043 void PrintBFS::print() {
2044   if (_print_list.length() > 0 ) {
2045     print_header();
2046     for (int i = 0; i < _print_list.length(); i++) {
2047       const Node* n = _print_list.at(i);
2048       print_node(n);
2049     }
2050   } else {
2051     tty->print("No nodes to print.\n");
2052   }
2053 }
2054 
2055 void PrintBFS::print_options_help(bool print_examples) {
2056   tty->print("Usage: node->dump_bfs(int max_distance, Node* target, char* options)\n");
2057   tty->print("\n");
2058   tty->print("Use cases:\n");
2059   tty->print("  BFS traversal: no target required\n");
2060   tty->print("  shortest path: set target\n");
2061   tty->print("  all paths: set target and put 'A' in options\n");
2062   tty->print("  detect loop: subcase of all paths, have start==target\n");
2063   tty->print("\n");
2064   tty->print("Arguments:\n");
2065   tty->print("  this/start: staring point of BFS\n");
2066   tty->print("  target:\n");
2067   tty->print("    if nullptr: simple BFS\n");
2068   tty->print("    else: shortest path or all paths between this/start and target\n");
2069   tty->print("  options:\n");
2070   tty->print("    if nullptr: same as \"cdmox@B\"\n");
2071   tty->print("    else: use combination of following characters\n");
2072   tty->print("      h: display this help info\n");
2073   tty->print("      H: display this help info, with examples\n");
2074   tty->print("      +: traverse in-edges (on if neither + nor -)\n");
2075   tty->print("      -: traverse out-edges\n");
2076   tty->print("      c: visit control nodes\n");
2077   tty->print("      d: visit data nodes\n");
2078   tty->print("      m: visit memory nodes\n");
2079   tty->print("      o: visit other nodes\n");
2080   tty->print("      x: visit mixed nodes\n");
2081   tty->print("      C: boundary control nodes\n");
2082   tty->print("      D: boundary data nodes\n");
2083   tty->print("      M: boundary memory nodes\n");
2084   tty->print("      O: boundary other nodes\n");
2085   tty->print("      X: boundary mixed nodes\n");
2086   tty->print("      #: display node category in color (not supported in all terminals)\n");
2087   tty->print("      S: sort displayed nodes by node idx\n");
2088   tty->print("      A: all paths (not just shortest path to target)\n");
2089   tty->print("      @: print old nodes - before matching (if available)\n");
2090   tty->print("      B: print scheduling blocks (if available)\n");
2091   tty->print("      $: dump only, no header, no other columns\n");
2092   tty->print("\n");
2093   tty->print("recursively follow edges to nodes with permitted visit types,\n");
2094   tty->print("on the boundary additionally display nodes allowed in boundary types\n");
2095   tty->print("Note: the categories can be overlapping. For example a mixed node\n");
2096   tty->print("      can contain control and memory output. Some from the other\n");
2097   tty->print("      category are also control (Halt, Return, etc).\n");
2098   tty->print("\n");
2099   tty->print("output columns:\n");
2100   tty->print("  dist:  BFS distance to this/start\n");
2101   tty->print("  apd:   all paths distance (d_start + d_target)\n");
2102   tty->print("  block: block identifier, based on _pre_order\n");
2103   tty->print("  head:  first node in block\n");
2104   tty->print("  idom:  head node of idom block\n");
2105   tty->print("  depth: depth of block (_dom_depth)\n");
2106   tty->print("  old:   old IR node - before matching\n");
2107   tty->print("  dump:  node->dump()\n");
2108   tty->print("\n");
2109   tty->print("Note: if none of the \"cmdxo\" characters are in the options string\n");
2110   tty->print("      then we set all of them.\n");
2111   tty->print("      This allows for short strings like \"#\" for colored input traversal\n");
2112   tty->print("      or \"-#\" for colored output traversal.\n");
2113   if (print_examples) {
2114     tty->print("\n");
2115     tty->print("Examples:\n");
2116     tty->print("  if->dump_bfs(10, 0, \"+cxo\")\n");
2117     tty->print("    starting at some if node, traverse inputs recursively\n");
2118     tty->print("    only along control (mixed and other can also be control)\n");
2119     tty->print("  phi->dump_bfs(5, 0, \"-dxo\")\n");
2120     tty->print("    starting at phi node, traverse outputs recursively\n");
2121     tty->print("    only along data (mixed and other can also have data flow)\n");
2122     tty->print("  find_node(385)->dump_bfs(3, 0, \"cdmox+#@B\")\n");
2123     tty->print("    find inputs of node 385, up to 3 nodes up (+)\n");
2124     tty->print("    traverse all nodes (cdmox), use colors (#)\n");
2125     tty->print("    display old nodes and blocks, if they exist\n");
2126     tty->print("    useful call to start with\n");
2127     tty->print("  find_node(102)->dump_bfs(10, 0, \"dCDMOX-\")\n");
2128     tty->print("    find non-data dependencies of a data node\n");
2129     tty->print("    follow data node outputs until we find another category\n");
2130     tty->print("    node as the boundary\n");
2131     tty->print("  x->dump_bfs(10, y, 0)\n");
2132     tty->print("    find shortest path from x to y, along any edge or node\n");
2133     tty->print("    will not find a path if it is longer than 10\n");
2134     tty->print("    useful to find how x and y are related\n");
2135     tty->print("  find_node(741)->dump_bfs(20, find_node(746), \"c+\")\n");
2136     tty->print("    find shortest control path between two nodes\n");
2137     tty->print("  find_node(741)->dump_bfs(8, find_node(746), \"cdmox+A\")\n");
2138     tty->print("    find all paths (A) between two nodes of length at most 8\n");
2139     tty->print("  find_node(741)->dump_bfs(7, find_node(741), \"c+A\")\n");
2140     tty->print("    find all control loops for this node\n");
2141   }
2142 }
2143 
2144 bool PrintBFS::parse_options() {
2145   if (_options == nullptr) {
2146     _options = "cdmox@B"; // default options
2147   }
2148   size_t len = strlen(_options);
2149   for (size_t i = 0; i < len; i++) {
2150     switch (_options[i]) {
2151       case '+':
2152         _traverse_inputs = true;
2153         break;
2154       case '-':
2155         _traverse_outputs = true;
2156         break;
2157       case 'c':
2158         _filter_visit._control = true;
2159         break;
2160       case 'm':
2161         _filter_visit._memory = true;
2162         break;
2163       case 'd':
2164         _filter_visit._data = true;
2165         break;
2166       case 'x':
2167         _filter_visit._mixed = true;
2168         break;
2169       case 'o':
2170         _filter_visit._other = true;
2171         break;
2172       case 'C':
2173         _filter_boundary._control = true;
2174         break;
2175       case 'M':
2176         _filter_boundary._memory = true;
2177         break;
2178       case 'D':
2179         _filter_boundary._data = true;
2180         break;
2181       case 'X':
2182         _filter_boundary._mixed = true;
2183         break;
2184       case 'O':
2185         _filter_boundary._other = true;
2186         break;
2187       case 'S':
2188         _sort_idx = true;
2189         break;
2190       case 'A':
2191         _all_paths = true;
2192         break;
2193       case '#':
2194         _use_color = true;
2195         break;
2196       case 'B':
2197         _print_blocks = true;
2198         break;
2199       case '@':
2200         _print_old = true;
2201         break;
2202       case '$':
2203         _dump_only = true;
2204         break;
2205       case 'h':
2206         print_options_help(false);
2207         return false;
2208        case 'H':
2209         print_options_help(true);
2210         return false;
2211       default:
2212         tty->print_cr("dump_bfs: Unrecognized option \'%c\'", _options[i]);
2213         tty->print_cr("for help, run: find_node(0)->dump_bfs(0,0,\"H\")");
2214         return false;
2215     }
2216   }
2217   if (!_traverse_inputs && !_traverse_outputs) {
2218     _traverse_inputs = true;
2219   }
2220   if (_filter_visit.is_empty()) {
2221     _filter_visit.set_all();
2222   }
2223   Compile* C = Compile::current();
2224   _print_old &= (C->matcher() != nullptr); // only show old if there are new
2225   _print_blocks &= (C->cfg() != nullptr); // only show blocks if available
2226   return true;
2227 }
2228 
2229 void PrintBFS::DumpConfigColored::pre_dump(outputStream* st, const Node* n) {
2230   if (!_bfs->_use_color) {
2231     return;
2232   }
2233   Info* info = _bfs->find_info(n);
2234   if (info == nullptr || !info->is_marked()) {
2235     return;
2236   }
2237 
2238   const Type* t = n->bottom_type();
2239   switch (t->category()) {
2240     case Type::Category::Data:
2241       st->print("\u001b[34m");
2242       break;
2243     case Type::Category::Memory:
2244       st->print("\u001b[32m");
2245       break;
2246     case Type::Category::Mixed:
2247       st->print("\u001b[35m");
2248       break;
2249     case Type::Category::Control:
2250       st->print("\u001b[31m");
2251       break;
2252     case Type::Category::Other:
2253       st->print("\u001b[33m");
2254       break;
2255     case Type::Category::Undef:
2256       n->dump();
2257       assert(false, "category undef ??");
2258       break;
2259     default:
2260       n->dump();
2261       assert(false, "not covered");
2262       break;
2263   }
2264 }
2265 
2266 void PrintBFS::DumpConfigColored::post_dump(outputStream* st) {
2267   if (!_bfs->_use_color) {
2268     return;
2269   }
2270   st->print("\u001b[0m"); // white
2271 }
2272 
2273 Node* PrintBFS::old_node(const Node* n) {
2274   Compile* C = Compile::current();
2275   if (C->matcher() == nullptr || !C->node_arena()->contains(n)) {
2276     return (Node*)nullptr;
2277   } else {
2278     return C->matcher()->find_old_node(n);
2279   }
2280 }
2281 
2282 void PrintBFS::print_node_idx(const Node* n) {
2283   Compile* C = Compile::current();
2284   char buf[30];
2285   if (n == nullptr) {
2286     sprintf(buf,"_");           // null
2287   } else if (C->node_arena()->contains(n)) {
2288     sprintf(buf, "%d", n->_idx);  // new node
2289   } else {
2290     sprintf(buf, "o%d", n->_idx); // old node
2291   }
2292   tty->print("%6s", buf);
2293 }
2294 
2295 void PrintBFS::print_block_id(const Block* b) {
2296   Compile* C = Compile::current();
2297   char buf[30];
2298   sprintf(buf, "B%d", b->_pre_order);
2299   tty->print("%7s", buf);
2300 }
2301 
2302 void PrintBFS::print_node_block(const Node* n) {
2303   Compile* C = Compile::current();
2304   Block* b = C->node_arena()->contains(n)
2305              ? C->cfg()->get_block_for_node(n)
2306              : nullptr; // guard against old nodes
2307   if (b == nullptr) {
2308     tty->print("      _"); // Block
2309     tty->print("     _");  // head
2310     tty->print("     _");  // idom
2311     tty->print("      _"); // depth
2312   } else {
2313     print_block_id(b);
2314     print_node_idx(b->head());
2315     if (b->_idom) {
2316       print_node_idx(b->_idom->head());
2317     } else {
2318       tty->print("     _"); // idom
2319     }
2320     tty->print("%6d ", b->_dom_depth);
2321   }
2322 }
2323 
2324 // filter, and add to worklist, add info, note traversal edges
2325 void PrintBFS::maybe_traverse(const Node* src, const Node* dst) {
2326   if (dst != nullptr &&
2327      (_filter_visit.accepts(dst) ||
2328       _filter_boundary.accepts(dst) ||
2329       dst == _start)) { // correct category or start?
2330     if (find_info(dst) == nullptr) {
2331       // never visited - set up info
2332       _worklist.push(dst);
2333       int d = 0;
2334       if (dst != _start) {
2335         d = find_info(src)->distance() + 1;
2336       }
2337       make_info(dst, d);
2338     }
2339     if (src != dst) {
2340       // traversal edges useful during select
2341       find_info(dst)->edge_bwd.push(src);
2342     }
2343   }
2344 }
2345 
2346 void PrintBFS::print_header() const {
2347   if (_dump_only) {
2348     return; // no header in dump only mode
2349   }
2350   tty->print("dist");                         // distance
2351   if (_all_paths) {
2352     tty->print(" apd");                       // all paths distance
2353   }
2354   if (_print_blocks) {
2355     tty->print(" [block  head  idom depth]"); // block
2356   }
2357   if (_print_old) {
2358     tty->print("   old");                     // old node
2359   }
2360   tty->print(" dump\n");                      // node dump
2361   tty->print("---------------------------------------------\n");
2362 }
2363 
2364 void PrintBFS::print_node(const Node* n) {
2365   if (_dump_only) {
2366     n->dump("\n", false, tty, &_dcc);
2367     return;
2368   }
2369   tty->print("%4d", find_info(n)->distance());// distance
2370   if (_all_paths) {
2371     Info* info = find_info(n);
2372     int apd = info->distance() + info->distance_from_target();
2373     tty->print("%4d", apd);                   // all paths distance
2374   }
2375   if (_print_blocks) {
2376     print_node_block(n);                      // block
2377   }
2378   if (_print_old) {
2379     print_node_idx(old_node(n));              // old node
2380   }
2381   tty->print(" ");
2382   n->dump("\n", false, tty, &_dcc);           // node dump
2383 }
2384 
2385 //------------------------------dump_bfs--------------------------------------
2386 // Call this from debugger
2387 // Useful for BFS traversal, shortest path, all path, loop detection, etc
2388 // Designed to be more readable, and provide additional info
2389 // To find all options, run:
2390 //   find_node(0)->dump_bfs(0,0,"H")
2391 void Node::dump_bfs(const int max_distance, Node* target, const char* options) const {
2392   PrintBFS bfs(this, max_distance, target, options);
2393   bfs.run();
2394 }
2395 
2396 // Call this from debugger, with default arguments
2397 void Node::dump_bfs(const int max_distance) const {
2398   dump_bfs(max_distance, nullptr, nullptr);
2399 }
2400 
2401 // log10 rounded down
2402 uint log10(const uint i) {
2403   uint v = 10;
2404   uint e = 0;
2405   while(v <= i) {
2406     v *= 10;
2407     e++;
2408   }
2409   return e;
2410 }
2411 
2412 // -----------------------------dump_idx---------------------------------------
2413 void Node::dump_idx(bool align, outputStream* st, DumpConfig* dc) const {
2414   if (dc != nullptr) {
2415     dc->pre_dump(st, this);
2416   }
2417   Compile* C = Compile::current();
2418   bool is_new = C->node_arena()->contains(this);
2419   if (align) { // print prefix empty spaces$
2420     // +1 for leading digit, +1 for "o"
2421     uint max_width = log10(C->unique()) + 2;
2422     // +1 for leading digit, maybe +1 for "o"
2423     uint width = log10(_idx) + 1 + (is_new ? 0 : 1);
2424     while (max_width > width) {
2425       st->print(" ");
2426       width++;
2427     }
2428   }
2429   if (!is_new) {
2430     st->print("o");
2431   }
2432   st->print("%d", _idx);
2433   if (dc != nullptr) {
2434     dc->post_dump(st);
2435   }
2436 }
2437 
2438 // -----------------------------dump_name--------------------------------------
2439 void Node::dump_name(outputStream* st, DumpConfig* dc) const {
2440   if (dc != nullptr) {
2441     dc->pre_dump(st, this);
2442   }
2443   st->print("%s", Name());
2444   if (dc != nullptr) {
2445     dc->post_dump(st);
2446   }
2447 }
2448 
2449 // -----------------------------Name-------------------------------------------
2450 extern const char *NodeClassNames[];
2451 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
2452 
2453 static bool is_disconnected(const Node* n) {
2454   for (uint i = 0; i < n->req(); i++) {
2455     if (n->in(i) != NULL)  return false;
2456   }
2457   return true;
2458 }
2459 
2460 #ifdef ASSERT
2461 void Node::dump_orig(outputStream *st, bool print_key) const {
2462   Compile* C = Compile::current();
2463   Node* orig = _debug_orig;
2464   if (not_a_node(orig)) orig = NULL;
2465   if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
2466   if (orig == NULL) return;
2467   if (print_key) {
2468     st->print(" !orig=");
2469   }
2470   Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
2471   if (not_a_node(fast)) fast = NULL;
2472   while (orig != NULL) {
2473     bool discon = is_disconnected(orig);  // if discon, print [123] else 123
2474     if (discon) st->print("[");
2475     if (!Compile::current()->node_arena()->contains(orig))
2476       st->print("o");
2477     st->print("%d", orig->_idx);
2478     if (discon) st->print("]");
2479     orig = orig->debug_orig();
2480     if (not_a_node(orig)) orig = NULL;
2481     if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
2482     if (orig != NULL) st->print(",");
2483     if (fast != NULL) {
2484       // Step fast twice for each single step of orig:
2485       fast = fast->debug_orig();
2486       if (not_a_node(fast)) fast = NULL;
2487       if (fast != NULL && fast != orig) {
2488         fast = fast->debug_orig();
2489         if (not_a_node(fast)) fast = NULL;
2490       }
2491       if (fast == orig) {
2492         st->print("...");
2493         break;
2494       }
2495     }
2496   }
2497 }
2498 
2499 void Node::set_debug_orig(Node* orig) {
2500   _debug_orig = orig;
2501   if (BreakAtNode == 0)  return;
2502   if (not_a_node(orig))  orig = NULL;
2503   int trip = 10;
2504   while (orig != NULL) {
2505     if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
2506       tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
2507                     this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
2508       BREAKPOINT;
2509     }
2510     orig = orig->debug_orig();
2511     if (not_a_node(orig))  orig = NULL;
2512     if (trip-- <= 0)  break;
2513   }
2514 }
2515 #endif //ASSERT
2516 
2517 //------------------------------dump------------------------------------------
2518 // Dump a Node
2519 void Node::dump(const char* suffix, bool mark, outputStream* st, DumpConfig* dc) const {
2520   Compile* C = Compile::current();
2521   bool is_new = C->node_arena()->contains(this);
2522   C->_in_dump_cnt++;
2523 
2524   // idx mark name ===
2525   dump_idx(true, st, dc);
2526   st->print(mark ? " >" : "  ");
2527   dump_name(st, dc);
2528   st->print("  === ");
2529 
2530   // Dump the required and precedence inputs
2531   dump_req(st, dc);
2532   dump_prec(st, dc);
2533   // Dump the outputs
2534   dump_out(st, dc);
2535 
2536   if (is_disconnected(this)) {
2537 #ifdef ASSERT
2538     st->print("  [%d]",debug_idx());
2539     dump_orig(st);
2540 #endif
2541     st->cr();
2542     C->_in_dump_cnt--;
2543     return;                     // don't process dead nodes
2544   }
2545 
2546   if (C->clone_map().value(_idx) != 0) {
2547     C->clone_map().dump(_idx);
2548   }
2549   // Dump node-specific info
2550   dump_spec(st);
2551 #ifdef ASSERT
2552   // Dump the non-reset _debug_idx
2553   if (Verbose && WizardMode) {
2554     st->print("  [%d]",debug_idx());
2555   }
2556 #endif
2557 
2558   const Type *t = bottom_type();
2559 
2560   if (t != NULL && (t->isa_instptr() || t->isa_instklassptr())) {
2561     const TypeInstPtr  *toop = t->isa_instptr();
2562     const TypeInstKlassPtr *tkls = t->isa_instklassptr();
2563     ciKlass*           klass = toop ? toop->instance_klass() : (tkls ? tkls->instance_klass() : NULL );
2564     if (klass && klass->is_loaded() && ((toop && toop->is_interface()) || (tkls && tkls->is_interface()))) {
2565       st->print("  Interface:");
2566     } else if (toop) {
2567       st->print("  Oop:");
2568     } else if (tkls) {
2569       st->print("  Klass:");
2570     }
2571     t->dump_on(st);
2572   } else if (t == Type::MEMORY) {
2573     st->print("  Memory:");
2574     MemNode::dump_adr_type(this, adr_type(), st);
2575   } else if (Verbose || WizardMode) {
2576     st->print("  Type:");
2577     if (t) {
2578       t->dump_on(st);
2579     } else {
2580       st->print("no type");
2581     }
2582   } else if (t->isa_vect() && this->is_MachSpillCopy()) {
2583     // Dump MachSpillcopy vector type.
2584     t->dump_on(st);
2585   }
2586   if (is_new) {
2587     DEBUG_ONLY(dump_orig(st));
2588     Node_Notes* nn = C->node_notes_at(_idx);
2589     if (nn != NULL && !nn->is_clear()) {
2590       if (nn->jvms() != NULL) {
2591         st->print(" !jvms:");
2592         nn->jvms()->dump_spec(st);
2593       }
2594     }
2595   }
2596   if (suffix) st->print("%s", suffix);
2597   C->_in_dump_cnt--;
2598 }
2599 
2600 // call from debugger: dump node to tty with newline
2601 void Node::dump() const {
2602   dump("\n");
2603 }
2604 
2605 //------------------------------dump_req--------------------------------------
2606 void Node::dump_req(outputStream* st, DumpConfig* dc) const {
2607   // Dump the required input edges
2608   for (uint i = 0; i < req(); i++) {    // For all required inputs
2609     Node* d = in(i);
2610     if (d == NULL) {
2611       st->print("_ ");
2612     } else if (not_a_node(d)) {
2613       st->print("not_a_node ");  // uninitialized, sentinel, garbage, etc.
2614     } else {
2615       d->dump_idx(false, st, dc);
2616       st->print(" ");
2617     }
2618   }
2619 }
2620 
2621 
2622 //------------------------------dump_prec-------------------------------------
2623 void Node::dump_prec(outputStream* st, DumpConfig* dc) const {
2624   // Dump the precedence edges
2625   int any_prec = 0;
2626   for (uint i = req(); i < len(); i++) {       // For all precedence inputs
2627     Node* p = in(i);
2628     if (p != NULL) {
2629       if (!any_prec++) st->print(" |");
2630       if (not_a_node(p)) { st->print("not_a_node "); continue; }
2631       p->dump_idx(false, st, dc);
2632       st->print(" ");
2633     }
2634   }
2635 }
2636 
2637 //------------------------------dump_out--------------------------------------
2638 void Node::dump_out(outputStream* st, DumpConfig* dc) const {
2639   // Delimit the output edges
2640   st->print(" [[ ");
2641   // Dump the output edges
2642   for (uint i = 0; i < _outcnt; i++) {    // For all outputs
2643     Node* u = _out[i];
2644     if (u == NULL) {
2645       st->print("_ ");
2646     } else if (not_a_node(u)) {
2647       st->print("not_a_node ");
2648     } else {
2649       u->dump_idx(false, st, dc);
2650       st->print(" ");
2651     }
2652   }
2653   st->print("]] ");
2654 }
2655 
2656 //------------------------------dump-------------------------------------------
2657 // call from debugger: dump Node's inputs (or outputs if d negative)
2658 void Node::dump(int d) const {
2659   dump_bfs(abs(d), nullptr, (d > 0) ? "+$" : "-$");
2660 }
2661 
2662 //------------------------------dump_ctrl--------------------------------------
2663 // call from debugger: dump Node's control inputs (or outputs if d negative)
2664 void Node::dump_ctrl(int d) const {
2665   dump_bfs(abs(d), nullptr, (d > 0) ? "+$c" : "-$c");
2666 }
2667 
2668 //-----------------------------dump_compact------------------------------------
2669 void Node::dump_comp() const {
2670   this->dump_comp("\n");
2671 }
2672 
2673 //-----------------------------dump_compact------------------------------------
2674 // Dump a Node in compact representation, i.e., just print its name and index.
2675 // Nodes can specify additional specifics to print in compact representation by
2676 // implementing dump_compact_spec.
2677 void Node::dump_comp(const char* suffix, outputStream *st) const {
2678   Compile* C = Compile::current();
2679   C->_in_dump_cnt++;
2680   st->print("%s(%d)", Name(), _idx);
2681   this->dump_compact_spec(st);
2682   if (suffix) {
2683     st->print("%s", suffix);
2684   }
2685   C->_in_dump_cnt--;
2686 }
2687 
2688 // VERIFICATION CODE
2689 // For each input edge to a node (ie - for each Use-Def edge), verify that
2690 // there is a corresponding Def-Use edge.
2691 //------------------------------verify_edges-----------------------------------
2692 void Node::verify_edges(Unique_Node_List &visited) {
2693   uint i, j, idx;
2694   int  cnt;
2695   Node *n;
2696 
2697   // Recursive termination test
2698   if (visited.member(this))  return;
2699   visited.push(this);
2700 
2701   // Walk over all input edges, checking for correspondence
2702   for( i = 0; i < len(); i++ ) {
2703     n = in(i);
2704     if (n != NULL && !n->is_top()) {
2705       // Count instances of (Node *)this
2706       cnt = 0;
2707       for (idx = 0; idx < n->_outcnt; idx++ ) {
2708         if (n->_out[idx] == (Node *)this)  cnt++;
2709       }
2710       assert( cnt > 0,"Failed to find Def-Use edge." );
2711       // Check for duplicate edges
2712       // walk the input array downcounting the input edges to n
2713       for( j = 0; j < len(); j++ ) {
2714         if( in(j) == n ) cnt--;
2715       }
2716       assert( cnt == 0,"Mismatched edge count.");
2717     } else if (n == NULL) {
2718       assert(i >= req() || i == 0 || is_Region() || is_Phi() || is_ArrayCopy() ||
2719              (is_Allocate() && i >= AllocateNode::InlineTypeNode) ||
2720              (is_Unlock() && i == req()-1)
2721               || (is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
2722              "only region, phi, arraycopy, allocate or unlock nodes have null data edges");
2723     } else {
2724       assert(n->is_top(), "sanity");
2725       // Nothing to check.
2726     }
2727   }
2728   // Recursive walk over all input edges
2729   for( i = 0; i < len(); i++ ) {
2730     n = in(i);
2731     if( n != NULL )
2732       in(i)->verify_edges(visited);
2733   }
2734 }
2735 
2736 // Verify all nodes if verify_depth is negative
2737 void Node::verify(int verify_depth, VectorSet& visited, Node_List& worklist) {
2738   assert(verify_depth != 0, "depth should not be 0");
2739   Compile* C = Compile::current();
2740   uint last_index_on_current_depth = worklist.size() - 1;
2741   verify_depth--; // Visiting the first node on depth 1
2742   // Only add nodes to worklist if verify_depth is negative (visit all nodes) or greater than 0
2743   bool add_to_worklist = verify_depth != 0;
2744 
2745   for (uint list_index = 0; list_index < worklist.size(); list_index++) {
2746     Node* n = worklist[list_index];
2747 
2748     if (n->is_Con() && n->bottom_type() == Type::TOP) {
2749       if (C->cached_top_node() == NULL) {
2750         C->set_cached_top_node((Node*)n);
2751       }
2752       assert(C->cached_top_node() == n, "TOP node must be unique");
2753     }
2754 
2755     uint in_len = n->len();
2756     for (uint i = 0; i < in_len; i++) {
2757       Node* x = n->_in[i];
2758       if (!x || x->is_top()) {
2759         continue;
2760       }
2761 
2762       // Verify my input has a def-use edge to me
2763       // Count use-def edges from n to x
2764       int cnt = 1;
2765       for (uint j = 0; j < i; j++) {
2766         if (n->_in[j] == x) {
2767           cnt++;
2768           break;
2769         }
2770       }
2771       if (cnt == 2) {
2772         // x is already checked as n's previous input, skip its duplicated def-use count checking
2773         continue;
2774       }
2775       for (uint j = i + 1; j < in_len; j++) {
2776         if (n->_in[j] == x) {
2777           cnt++;
2778         }
2779       }
2780 
2781       // Count def-use edges from x to n
2782       uint max = x->_outcnt;
2783       for (uint k = 0; k < max; k++) {
2784         if (x->_out[k] == n) {
2785           cnt--;
2786         }
2787       }
2788       assert(cnt == 0, "mismatched def-use edge counts");
2789 
2790       if (add_to_worklist && !visited.test_set(x->_idx)) {
2791         worklist.push(x);
2792       }
2793     }
2794 
2795     if (verify_depth > 0 && list_index == last_index_on_current_depth) {
2796       // All nodes on this depth were processed and its inputs are on the worklist. Decrement verify_depth and
2797       // store the current last list index which is the last node in the list with the new depth. All nodes
2798       // added afterwards will have a new depth again. Stop adding new nodes if depth limit is reached (=0).
2799       verify_depth--;
2800       if (verify_depth == 0) {
2801         add_to_worklist = false;
2802       }
2803       last_index_on_current_depth = worklist.size() - 1;
2804     }
2805   }
2806 }
2807 #endif // not PRODUCT
2808 
2809 //------------------------------Registers--------------------------------------
2810 // Do we Match on this edge index or not?  Generally false for Control
2811 // and true for everything else.  Weird for calls & returns.
2812 uint Node::match_edge(uint idx) const {
2813   return idx;                   // True for other than index 0 (control)
2814 }
2815 
2816 // Register classes are defined for specific machines
2817 const RegMask &Node::out_RegMask() const {
2818   ShouldNotCallThis();
2819   return RegMask::Empty;
2820 }
2821 
2822 const RegMask &Node::in_RegMask(uint) const {
2823   ShouldNotCallThis();
2824   return RegMask::Empty;
2825 }
2826 
2827 void Node_Array::grow(uint i) {
2828   assert(_max > 0, "invariant");
2829   uint old = _max;
2830   _max = next_power_of_2(i);
2831   _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2832   Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2833 }
2834 
2835 void Node_Array::insert(uint i, Node* n) {
2836   if (_nodes[_max - 1]) {
2837     grow(_max);
2838   }
2839   Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i + 1], ((_max - i - 1) * sizeof(Node*)));
2840   _nodes[i] = n;
2841 }
2842 
2843 void Node_Array::remove(uint i) {
2844   Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i + 1], (HeapWord*)&_nodes[i], ((_max - i - 1) * sizeof(Node*)));
2845   _nodes[_max - 1] = NULL;
2846 }
2847 
2848 void Node_Array::dump() const {
2849 #ifndef PRODUCT
2850   for (uint i = 0; i < _max; i++) {
2851     Node* nn = _nodes[i];
2852     if (nn != NULL) {
2853       tty->print("%5d--> ",i); nn->dump();
2854     }
2855   }
2856 #endif
2857 }
2858 
2859 //--------------------------is_iteratively_computed------------------------------
2860 // Operation appears to be iteratively computed (such as an induction variable)
2861 // It is possible for this operation to return false for a loop-varying
2862 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2863 bool Node::is_iteratively_computed() {
2864   if (ideal_reg()) { // does operation have a result register?
2865     for (uint i = 1; i < req(); i++) {
2866       Node* n = in(i);
2867       if (n != NULL && n->is_Phi()) {
2868         for (uint j = 1; j < n->req(); j++) {
2869           if (n->in(j) == this) {
2870             return true;
2871           }
2872         }
2873       }
2874     }
2875   }
2876   return false;
2877 }
2878 
2879 //--------------------------find_similar------------------------------
2880 // Return a node with opcode "opc" and same inputs as "this" if one can
2881 // be found; Otherwise return NULL;
2882 Node* Node::find_similar(int opc) {
2883   if (req() >= 2) {
2884     Node* def = in(1);
2885     if (def && def->outcnt() >= 2) {
2886       for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2887         Node* use = def->fast_out(i);
2888         if (use != this &&
2889             use->Opcode() == opc &&
2890             use->req() == req()) {
2891           uint j;
2892           for (j = 0; j < use->req(); j++) {
2893             if (use->in(j) != in(j)) {
2894               break;
2895             }
2896           }
2897           if (j == use->req()) {
2898             return use;
2899           }
2900         }
2901       }
2902     }
2903   }
2904   return NULL;
2905 }
2906 
2907 
2908 //--------------------------unique_ctrl_out_or_null-------------------------
2909 // Return the unique control out if only one. Null if none or more than one.
2910 Node* Node::unique_ctrl_out_or_null() const {
2911   Node* found = NULL;
2912   for (uint i = 0; i < outcnt(); i++) {
2913     Node* use = raw_out(i);
2914     if (use->is_CFG() && use != this) {
2915       if (found != NULL) {
2916         return NULL;
2917       }
2918       found = use;
2919     }
2920   }
2921   return found;
2922 }
2923 
2924 //--------------------------unique_ctrl_out------------------------------
2925 // Return the unique control out. Asserts if none or more than one control out.
2926 Node* Node::unique_ctrl_out() const {
2927   Node* ctrl = unique_ctrl_out_or_null();
2928   assert(ctrl != NULL, "control out is assumed to be unique");
2929   return ctrl;
2930 }
2931 
2932 void Node::ensure_control_or_add_prec(Node* c) {
2933   if (in(0) == NULL) {
2934     set_req(0, c);
2935   } else if (in(0) != c) {
2936     add_prec(c);
2937   }
2938 }
2939 
2940 bool Node::is_dead_loop_safe() const {
2941   if (is_Phi()) {
2942     return true;
2943   }
2944   if (is_Proj() && in(0) == NULL)  {
2945     return true;
2946   }
2947   if ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0) {
2948     if (!is_Proj()) {
2949       return true;
2950     }
2951     if (in(0)->is_Allocate()) {
2952       return false;
2953     }
2954     // MemNode::can_see_stored_value() peeks through the boxing call
2955     if (in(0)->is_CallStaticJava() && in(0)->as_CallStaticJava()->is_boxing_method()) {
2956       return false;
2957     }
2958     return true;
2959   }
2960   return false;
2961 }
2962 
2963 //=============================================================================
2964 //------------------------------yank-------------------------------------------
2965 // Find and remove
2966 void Node_List::yank( Node *n ) {
2967   uint i;
2968   for (i = 0; i < _cnt; i++) {
2969     if (_nodes[i] == n) {
2970       break;
2971     }
2972   }
2973 
2974   if (i < _cnt) {
2975     _nodes[i] = _nodes[--_cnt];
2976   }
2977 }
2978 
2979 //------------------------------dump-------------------------------------------
2980 void Node_List::dump() const {
2981 #ifndef PRODUCT
2982   for (uint i = 0; i < _cnt; i++) {
2983     if (_nodes[i]) {
2984       tty->print("%5d--> ", i);
2985       _nodes[i]->dump();
2986     }
2987   }
2988 #endif
2989 }
2990 
2991 void Node_List::dump_simple() const {
2992 #ifndef PRODUCT
2993   for (uint i = 0; i < _cnt; i++) {
2994     if( _nodes[i] ) {
2995       tty->print(" %d", _nodes[i]->_idx);
2996     } else {
2997       tty->print(" NULL");
2998     }
2999   }
3000 #endif
3001 }
3002 
3003 //=============================================================================
3004 //------------------------------remove-----------------------------------------
3005 void Unique_Node_List::remove(Node* n) {
3006   if (_in_worklist.test(n->_idx)) {
3007     for (uint i = 0; i < size(); i++) {
3008       if (_nodes[i] == n) {
3009         map(i, Node_List::pop());
3010         _in_worklist.remove(n->_idx);
3011         return;
3012       }
3013     }
3014     ShouldNotReachHere();
3015   }
3016 }
3017 
3018 //-----------------------remove_useless_nodes----------------------------------
3019 // Remove useless nodes from worklist
3020 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
3021   for (uint i = 0; i < size(); ++i) {
3022     Node *n = at(i);
3023     assert( n != NULL, "Did not expect null entries in worklist");
3024     if (!useful.test(n->_idx)) {
3025       _in_worklist.remove(n->_idx);
3026       map(i, Node_List::pop());
3027       --i;  // Visit popped node
3028       // If it was last entry, loop terminates since size() was also reduced
3029     }
3030   }
3031 }
3032 
3033 //=============================================================================
3034 void Node_Stack::grow() {
3035   size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
3036   size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
3037   size_t max = old_max << 1;             // max * 2
3038   _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
3039   _inode_max = _inodes + max;
3040   _inode_top = _inodes + old_top;        // restore _top
3041 }
3042 
3043 // Node_Stack is used to map nodes.
3044 Node* Node_Stack::find(uint idx) const {
3045   uint sz = size();
3046   for (uint i = 0; i < sz; i++) {
3047     if (idx == index_at(i)) {
3048       return node_at(i);
3049     }
3050   }
3051   return NULL;
3052 }
3053 
3054 //=============================================================================
3055 uint TypeNode::size_of() const { return sizeof(*this); }
3056 #ifndef PRODUCT
3057 void TypeNode::dump_spec(outputStream *st) const {
3058   if (!Verbose && !WizardMode) {
3059     // standard dump does this in Verbose and WizardMode
3060     st->print(" #"); _type->dump_on(st);
3061   }
3062 }
3063 
3064 void TypeNode::dump_compact_spec(outputStream *st) const {
3065   st->print("#");
3066   _type->dump_on(st);
3067 }
3068 #endif
3069 uint TypeNode::hash() const {
3070   return Node::hash() + _type->hash();
3071 }
3072 bool TypeNode::cmp(const Node& n) const {
3073   return !Type::cmp(_type, ((TypeNode&)n)._type);
3074 }
3075 const Type* TypeNode::bottom_type() const { return _type; }
3076 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
3077 
3078 //------------------------------ideal_reg--------------------------------------
3079 uint TypeNode::ideal_reg() const {
3080   return _type->ideal_reg();
3081 }