1 /*
   2  * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2024, Alibaba Group Holding Limited. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #ifndef SHARE_OPTO_NODE_HPP
  27 #define SHARE_OPTO_NODE_HPP
  28 
  29 #include "libadt/vectset.hpp"
  30 #include "opto/compile.hpp"
  31 #include "opto/type.hpp"
  32 #include "utilities/copy.hpp"
  33 
  34 // Portions of code courtesy of Clifford Click
  35 
  36 // Optimization - Graph Style
  37 
  38 
  39 class AbstractLockNode;
  40 class AddNode;
  41 class AddPNode;
  42 class AliasInfo;
  43 class AllocateArrayNode;
  44 class AllocateNode;
  45 class ArrayCopyNode;
  46 class BaseCountedLoopNode;
  47 class BaseCountedLoopEndNode;
  48 class BlackholeNode;
  49 class Block;
  50 class BoolNode;
  51 class BoxLockNode;
  52 class CMoveNode;
  53 class CallDynamicJavaNode;
  54 class CallJavaNode;
  55 class CallLeafNode;
  56 class CallLeafNoFPNode;
  57 class CallNode;
  58 class CallRuntimeNode;
  59 class CallStaticJavaNode;
  60 class CastFFNode;
  61 class CastDDNode;
  62 class CastVVNode;
  63 class CastIINode;
  64 class CastLLNode;
  65 class CastPPNode;
  66 class CatchNode;
  67 class CatchProjNode;
  68 class CheckCastPPNode;
  69 class ClearArrayNode;
  70 class CmpNode;
  71 class CodeBuffer;
  72 class ConstraintCastNode;
  73 class ConNode;
  74 class ConINode;
  75 class ConvertNode;
  76 class CompareAndSwapNode;
  77 class CompareAndExchangeNode;
  78 class CountedLoopNode;
  79 class CountedLoopEndNode;
  80 class DecodeNarrowPtrNode;
  81 class DecodeNNode;
  82 class DecodeNKlassNode;
  83 class EncodeNarrowPtrNode;
  84 class EncodePNode;
  85 class EncodePKlassNode;
  86 class FastLockNode;
  87 class FastUnlockNode;
  88 class HaltNode;
  89 class IfNode;
  90 class IfProjNode;
  91 class IfFalseNode;
  92 class IfTrueNode;
  93 class InitializeNode;
  94 class JVMState;
  95 class JumpNode;
  96 class JumpProjNode;
  97 class LoadNode;
  98 class LoadStoreNode;
  99 class LoadStoreConditionalNode;
 100 class LockNode;
 101 class LongCountedLoopNode;
 102 class LongCountedLoopEndNode;
 103 class LoopNode;
 104 class LShiftNode;
 105 class MachBranchNode;
 106 class MachCallDynamicJavaNode;
 107 class MachCallJavaNode;
 108 class MachCallLeafNode;
 109 class MachCallNode;
 110 class MachCallRuntimeNode;
 111 class MachCallStaticJavaNode;
 112 class MachConstantBaseNode;
 113 class MachConstantNode;
 114 class MachGotoNode;
 115 class MachIfNode;
 116 class MachJumpNode;
 117 class MachNode;
 118 class MachNullCheckNode;
 119 class MachProjNode;
 120 class MachReturnNode;
 121 class MachSafePointNode;
 122 class MachSpillCopyNode;
 123 class MachTempNode;
 124 class MachMergeNode;
 125 class MachMemBarNode;
 126 class Matcher;
 127 class MemBarNode;
 128 class MemBarStoreStoreNode;
 129 class MemNode;
 130 class MergeMemNode;
 131 class MoveNode;
 132 class MulNode;
 133 class MultiNode;
 134 class MultiBranchNode;
 135 class NegNode;
 136 class NegVNode;
 137 class NeverBranchNode;
 138 class Opaque1Node;
 139 class OpaqueLoopInitNode;
 140 class OpaqueLoopStrideNode;
 141 class Opaque4Node;
 142 class OpaqueInitializedAssertionPredicateNode;
 143 class OuterStripMinedLoopNode;
 144 class OuterStripMinedLoopEndNode;
 145 class Node;
 146 class Node_Array;
 147 class Node_List;
 148 class Node_Stack;
 149 class OopMap;
 150 class ParmNode;
 151 class ParsePredicateNode;
 152 class PCTableNode;
 153 class PhaseCCP;
 154 class PhaseGVN;
 155 class PhaseIterGVN;
 156 class PhaseRegAlloc;
 157 class PhaseTransform;
 158 class PhaseValues;
 159 class PhiNode;
 160 class Pipeline;
 161 class PopulateIndexNode;
 162 class ProjNode;
 163 class RangeCheckNode;
 164 class ReductionNode;
 165 class RegMask;
 166 class RegionNode;
 167 class RootNode;
 168 class SafePointNode;
 169 class SafePointScalarObjectNode;
 170 class SafePointScalarMergeNode;
 171 class StartNode;
 172 class State;
 173 class StoreNode;
 174 class SubNode;
 175 class SubTypeCheckNode;
 176 class Type;
 177 class TypeNode;
 178 class UnlockNode;
 179 class VectorNode;
 180 class LoadVectorNode;
 181 class LoadVectorMaskedNode;
 182 class StoreVectorMaskedNode;
 183 class LoadVectorGatherNode;
 184 class LoadVectorGatherMaskedNode;
 185 class StoreVectorNode;
 186 class StoreVectorScatterNode;
 187 class StoreVectorScatterMaskedNode;
 188 class VerifyVectorAlignmentNode;
 189 class VectorMaskCmpNode;
 190 class VectorUnboxNode;
 191 class VectorSet;
 192 class VectorReinterpretNode;
 193 class ShiftVNode;
 194 class ExpandVNode;
 195 class CompressVNode;
 196 class CompressMNode;
 197 class C2_MacroAssembler;
 198 
 199 
 200 #ifndef OPTO_DU_ITERATOR_ASSERT
 201 #ifdef ASSERT
 202 #define OPTO_DU_ITERATOR_ASSERT 1
 203 #else
 204 #define OPTO_DU_ITERATOR_ASSERT 0
 205 #endif
 206 #endif //OPTO_DU_ITERATOR_ASSERT
 207 
 208 #if OPTO_DU_ITERATOR_ASSERT
 209 class DUIterator;
 210 class DUIterator_Fast;
 211 class DUIterator_Last;
 212 #else
 213 typedef uint   DUIterator;
 214 typedef Node** DUIterator_Fast;
 215 typedef Node** DUIterator_Last;
 216 #endif
 217 
 218 typedef ResizeableResourceHashtable<Node*, Node*, AnyObj::RESOURCE_AREA, mtCompiler> OrigToNewHashtable;
 219 
 220 // Node Sentinel
 221 #define NodeSentinel (Node*)-1
 222 
 223 // Unknown count frequency
 224 #define COUNT_UNKNOWN (-1.0f)
 225 
 226 //------------------------------Node-------------------------------------------
 227 // Nodes define actions in the program.  They create values, which have types.
 228 // They are both vertices in a directed graph and program primitives.  Nodes
 229 // are labeled; the label is the "opcode", the primitive function in the lambda
 230 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 231 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 232 // the Node's function.  These inputs also define a Type equation for the Node.
 233 // Solving these Type equations amounts to doing dataflow analysis.
 234 // Control and data are uniformly represented in the graph.  Finally, Nodes
 235 // have a unique dense integer index which is used to index into side arrays
 236 // whenever I have phase-specific information.
 237 
 238 class Node {
 239   friend class VMStructs;
 240 
 241   // Lots of restrictions on cloning Nodes
 242   NONCOPYABLE(Node);
 243 
 244 public:
 245   friend class Compile;
 246   #if OPTO_DU_ITERATOR_ASSERT
 247   friend class DUIterator_Common;
 248   friend class DUIterator;
 249   friend class DUIterator_Fast;
 250   friend class DUIterator_Last;
 251   #endif
 252 
 253   // Because Nodes come and go, I define an Arena of Node structures to pull
 254   // from.  This should allow fast access to node creation & deletion.  This
 255   // field is a local cache of a value defined in some "program fragment" for
 256   // which these Nodes are just a part of.
 257 
 258   inline void* operator new(size_t x) throw() {
 259     Compile* C = Compile::current();
 260     Node* n = (Node*)C->node_arena()->AmallocWords(x);
 261     return (void*)n;
 262   }
 263 
 264   // Delete is a NOP
 265   void operator delete( void *ptr ) {}
 266   // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 267   void destruct(PhaseValues* phase);
 268 
 269   // Create a new Node.  Required is the number is of inputs required for
 270   // semantic correctness.
 271   Node( uint required );
 272 
 273   // Create a new Node with given input edges.
 274   // This version requires use of the "edge-count" new.
 275   // E.g.  new (C,3) FooNode( C, nullptr, left, right );
 276   Node( Node *n0 );
 277   Node( Node *n0, Node *n1 );
 278   Node( Node *n0, Node *n1, Node *n2 );
 279   Node( Node *n0, Node *n1, Node *n2, Node *n3 );
 280   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
 281   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
 282   Node( Node *n0, Node *n1, Node *n2, Node *n3,
 283             Node *n4, Node *n5, Node *n6 );
 284 
 285   // Clone an inherited Node given only the base Node type.
 286   Node* clone() const;
 287 
 288   // Clone a Node, immediately supplying one or two new edges.
 289   // The first and second arguments, if non-null, replace in(1) and in(2),
 290   // respectively.
 291   Node* clone_with_data_edge(Node* in1, Node* in2 = nullptr) const {
 292     Node* nn = clone();
 293     if (in1 != nullptr)  nn->set_req(1, in1);
 294     if (in2 != nullptr)  nn->set_req(2, in2);
 295     return nn;
 296   }
 297 
 298 private:
 299   // Shared setup for the above constructors.
 300   // Handles all interactions with Compile::current.
 301   // Puts initial values in all Node fields except _idx.
 302   // Returns the initial value for _idx, which cannot
 303   // be initialized by assignment.
 304   inline int Init(int req);
 305 
 306 //----------------- input edge handling
 307 protected:
 308   friend class PhaseCFG;        // Access to address of _in array elements
 309   Node **_in;                   // Array of use-def references to Nodes
 310   Node **_out;                  // Array of def-use references to Nodes
 311 
 312   // Input edges are split into two categories.  Required edges are required
 313   // for semantic correctness; order is important and nulls are allowed.
 314   // Precedence edges are used to help determine execution order and are
 315   // added, e.g., for scheduling purposes.  They are unordered and not
 316   // duplicated; they have no embedded nulls.  Edges from 0 to _cnt-1
 317   // are required, from _cnt to _max-1 are precedence edges.
 318   node_idx_t _cnt;              // Total number of required Node inputs.
 319 
 320   node_idx_t _max;              // Actual length of input array.
 321 
 322   // Output edges are an unordered list of def-use edges which exactly
 323   // correspond to required input edges which point from other nodes
 324   // to this one.  Thus the count of the output edges is the number of
 325   // users of this node.
 326   node_idx_t _outcnt;           // Total number of Node outputs.
 327 
 328   node_idx_t _outmax;           // Actual length of output array.
 329 
 330   // Grow the actual input array to the next larger power-of-2 bigger than len.
 331   void grow( uint len );
 332   // Grow the output array to the next larger power-of-2 bigger than len.
 333   void out_grow( uint len );
 334 
 335  public:
 336   // Each Node is assigned a unique small/dense number.  This number is used
 337   // to index into auxiliary arrays of data and bit vectors.
 338   // The field _idx is declared constant to defend against inadvertent assignments,
 339   // since it is used by clients as a naked field. However, the field's value can be
 340   // changed using the set_idx() method.
 341   //
 342   // The PhaseRenumberLive phase renumbers nodes based on liveness information.
 343   // Therefore, it updates the value of the _idx field. The parse-time _idx is
 344   // preserved in _parse_idx.
 345   const node_idx_t _idx;
 346   DEBUG_ONLY(const node_idx_t _parse_idx;)
 347   // IGV node identifier. Two nodes, possibly in different compilation phases,
 348   // have the same IGV identifier if (and only if) they are the very same node
 349   // (same memory address) or one is "derived" from the other (by e.g.
 350   // renumbering or matching). This identifier makes it possible to follow the
 351   // entire lifetime of a node in IGV even if its C2 identifier (_idx) changes.
 352   NOT_PRODUCT(node_idx_t _igv_idx;)
 353 
 354   // Get the (read-only) number of input edges
 355   uint req() const { return _cnt; }
 356   uint len() const { return _max; }
 357   // Get the (read-only) number of output edges
 358   uint outcnt() const { return _outcnt; }
 359 
 360 #if OPTO_DU_ITERATOR_ASSERT
 361   // Iterate over the out-edges of this node.  Deletions are illegal.
 362   inline DUIterator outs() const;
 363   // Use this when the out array might have changed to suppress asserts.
 364   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 365   // Does the node have an out at this position?  (Used for iteration.)
 366   inline bool has_out(DUIterator& i) const;
 367   inline Node*    out(DUIterator& i) const;
 368   // Iterate over the out-edges of this node.  All changes are illegal.
 369   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 370   inline Node*    fast_out(DUIterator_Fast& i) const;
 371   // Iterate over the out-edges of this node, deleting one at a time.
 372   inline DUIterator_Last last_outs(DUIterator_Last& min) const;
 373   inline Node*    last_out(DUIterator_Last& i) const;
 374   // The inline bodies of all these methods are after the iterator definitions.
 375 #else
 376   // Iterate over the out-edges of this node.  Deletions are illegal.
 377   // This iteration uses integral indexes, to decouple from array reallocations.
 378   DUIterator outs() const  { return 0; }
 379   // Use this when the out array might have changed to suppress asserts.
 380   DUIterator refresh_out_pos(DUIterator i) const { return i; }
 381 
 382   // Reference to the i'th output Node.  Error if out of bounds.
 383   Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
 384   // Does the node have an out at this position?  (Used for iteration.)
 385   bool has_out(DUIterator i) const { return i < _outcnt; }
 386 
 387   // Iterate over the out-edges of this node.  All changes are illegal.
 388   // This iteration uses a pointer internal to the out array.
 389   DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
 390     Node** out = _out;
 391     // Assign a limit pointer to the reference argument:
 392     max = out + (ptrdiff_t)_outcnt;
 393     // Return the base pointer:
 394     return out;
 395   }
 396   Node*    fast_out(DUIterator_Fast i) const  { return *i; }
 397   // Iterate over the out-edges of this node, deleting one at a time.
 398   // This iteration uses a pointer internal to the out array.
 399   DUIterator_Last last_outs(DUIterator_Last& min) const {
 400     Node** out = _out;
 401     // Assign a limit pointer to the reference argument:
 402     min = out;
 403     // Return the pointer to the start of the iteration:
 404     return out + (ptrdiff_t)_outcnt - 1;
 405   }
 406   Node*    last_out(DUIterator_Last i) const  { return *i; }
 407 #endif
 408 
 409   // Reference to the i'th input Node.  Error if out of bounds.
 410   Node* in(uint i) const { assert(i < _max, "oob: i=%d, _max=%d", i, _max); return _in[i]; }
 411   // Reference to the i'th input Node.  null if out of bounds.
 412   Node* lookup(uint i) const { return ((i < _max) ? _in[i] : nullptr); }
 413   // Reference to the i'th output Node.  Error if out of bounds.
 414   // Use this accessor sparingly.  We are going trying to use iterators instead.
 415   Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
 416   // Return the unique out edge.
 417   Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
 418   // Delete out edge at position 'i' by moving last out edge to position 'i'
 419   void  raw_del_out(uint i) {
 420     assert(i < _outcnt,"oob");
 421     assert(_outcnt > 0,"oob");
 422     #if OPTO_DU_ITERATOR_ASSERT
 423     // Record that a change happened here.
 424     debug_only(_last_del = _out[i]; ++_del_tick);
 425     #endif
 426     _out[i] = _out[--_outcnt];
 427     // Smash the old edge so it can't be used accidentally.
 428     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 429   }
 430 
 431 #ifdef ASSERT
 432   bool is_dead() const;
 433   static bool is_not_dead(const Node* n);
 434   bool is_reachable_from_root() const;
 435 #endif
 436   // Check whether node has become unreachable
 437   bool is_unreachable(PhaseIterGVN &igvn) const;
 438 
 439   // Set a required input edge, also updates corresponding output edge
 440   void add_req( Node *n ); // Append a NEW required input
 441   void add_req( Node *n0, Node *n1 ) {
 442     add_req(n0); add_req(n1); }
 443   void add_req( Node *n0, Node *n1, Node *n2 ) {
 444     add_req(n0); add_req(n1); add_req(n2); }
 445   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 446   void del_req( uint idx ); // Delete required edge & compact
 447   void del_req_ordered( uint idx ); // Delete required edge & compact with preserved order
 448   void ins_req( uint i, Node *n ); // Insert a NEW required input
 449   void set_req( uint i, Node *n ) {
 450     assert( is_not_dead(n), "can not use dead node");
 451     assert( i < _cnt, "oob: i=%d, _cnt=%d", i, _cnt);
 452     assert( !VerifyHashTableKeys || _hash_lock == 0,
 453             "remove node from hash table before modifying it");
 454     Node** p = &_in[i];    // cache this._in, across the del_out call
 455     if (*p != nullptr)  (*p)->del_out((Node *)this);
 456     (*p) = n;
 457     if (n != nullptr)      n->add_out((Node *)this);
 458     Compile::current()->record_modified_node(this);
 459   }
 460   // Light version of set_req() to init inputs after node creation.
 461   void init_req( uint i, Node *n ) {
 462     assert( (i == 0 && this == n) ||
 463             is_not_dead(n), "can not use dead node");
 464     assert( i < _cnt, "oob");
 465     assert( !VerifyHashTableKeys || _hash_lock == 0,
 466             "remove node from hash table before modifying it");
 467     assert( _in[i] == nullptr, "sanity");
 468     _in[i] = n;
 469     if (n != nullptr)      n->add_out((Node *)this);
 470     Compile::current()->record_modified_node(this);
 471   }
 472   // Find first occurrence of n among my edges:
 473   int find_edge(Node* n);
 474   int find_prec_edge(Node* n) {
 475     for (uint i = req(); i < len(); i++) {
 476       if (_in[i] == n) return i;
 477       if (_in[i] == nullptr) {
 478         DEBUG_ONLY( while ((++i) < len()) assert(_in[i] == nullptr, "Gap in prec edges!"); )
 479         break;
 480       }
 481     }
 482     return -1;
 483   }
 484   int replace_edge(Node* old, Node* neww, PhaseGVN* gvn = nullptr);
 485   int replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn);
 486   // null out all inputs to eliminate incoming Def-Use edges.
 487   void disconnect_inputs(Compile* C);
 488 
 489   // Quickly, return true if and only if I am Compile::current()->top().
 490   bool is_top() const {
 491     assert((this == (Node*) Compile::current()->top()) == (_out == nullptr), "");
 492     return (_out == nullptr);
 493   }
 494   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 495   void setup_is_top();
 496 
 497   // Strip away casting.  (It is depth-limited.)
 498   Node* uncast(bool keep_deps = false) const;
 499   // Return whether two Nodes are equivalent, after stripping casting.
 500   bool eqv_uncast(const Node* n, bool keep_deps = false) const {
 501     return (this->uncast(keep_deps) == n->uncast(keep_deps));
 502   }
 503 
 504   // Find out of current node that matches opcode.
 505   Node* find_out_with(int opcode);
 506   // Return true if the current node has an out that matches opcode.
 507   bool has_out_with(int opcode);
 508   // Return true if the current node has an out that matches any of the opcodes.
 509   bool has_out_with(int opcode1, int opcode2, int opcode3, int opcode4);
 510 
 511 private:
 512   static Node* uncast_helper(const Node* n, bool keep_deps);
 513 
 514   // Add an output edge to the end of the list
 515   void add_out( Node *n ) {
 516     if (is_top())  return;
 517     if( _outcnt == _outmax ) out_grow(_outcnt);
 518     _out[_outcnt++] = n;
 519   }
 520   // Delete an output edge
 521   void del_out( Node *n ) {
 522     if (is_top())  return;
 523     Node** outp = &_out[_outcnt];
 524     // Find and remove n
 525     do {
 526       assert(outp > _out, "Missing Def-Use edge");
 527     } while (*--outp != n);
 528     *outp = _out[--_outcnt];
 529     // Smash the old edge so it can't be used accidentally.
 530     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 531     // Record that a change happened here.
 532     #if OPTO_DU_ITERATOR_ASSERT
 533     debug_only(_last_del = n; ++_del_tick);
 534     #endif
 535   }
 536   // Close gap after removing edge.
 537   void close_prec_gap_at(uint gap) {
 538     assert(_cnt <= gap && gap < _max, "no valid prec edge");
 539     uint i = gap;
 540     Node *last = nullptr;
 541     for (; i < _max-1; ++i) {
 542       Node *next = _in[i+1];
 543       if (next == nullptr) break;
 544       last = next;
 545     }
 546     _in[gap] = last;  // Move last slot to empty one.
 547     _in[i] = nullptr; // null out last slot.
 548   }
 549 
 550 public:
 551   // Globally replace this node by a given new node, updating all uses.
 552   void replace_by(Node* new_node);
 553   // Globally replace this node by a given new node, updating all uses
 554   // and cutting input edges of old node.
 555   void subsume_by(Node* new_node, Compile* c) {
 556     replace_by(new_node);
 557     disconnect_inputs(c);
 558   }
 559   void set_req_X(uint i, Node *n, PhaseIterGVN *igvn);
 560   void set_req_X(uint i, Node *n, PhaseGVN *gvn);
 561   // Find the one non-null required input.  RegionNode only
 562   Node *nonnull_req() const;
 563   // Add or remove precedence edges
 564   void add_prec( Node *n );
 565   void rm_prec( uint i );
 566 
 567   // Note: prec(i) will not necessarily point to n if edge already exists.
 568   void set_prec( uint i, Node *n ) {
 569     assert(i < _max, "oob: i=%d, _max=%d", i, _max);
 570     assert(is_not_dead(n), "can not use dead node");
 571     assert(i >= _cnt, "not a precedence edge");
 572     // Avoid spec violation: duplicated prec edge.
 573     if (_in[i] == n) return;
 574     if (n == nullptr || find_prec_edge(n) != -1) {
 575       rm_prec(i);
 576       return;
 577     }
 578     if (_in[i] != nullptr) _in[i]->del_out((Node *)this);
 579     _in[i] = n;
 580     n->add_out((Node *)this);
 581     Compile::current()->record_modified_node(this);
 582   }
 583 
 584   // Set this node's index, used by cisc_version to replace current node
 585   void set_idx(uint new_idx) {
 586     const node_idx_t* ref = &_idx;
 587     *(node_idx_t*)ref = new_idx;
 588   }
 589   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 590   void swap_edges(uint i1, uint i2) {
 591     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 592     // Def-Use info is unchanged
 593     Node* n1 = in(i1);
 594     Node* n2 = in(i2);
 595     _in[i1] = n2;
 596     _in[i2] = n1;
 597     // If this node is in the hash table, make sure it doesn't need a rehash.
 598     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 599     // Flip swapped edges flag.
 600     if (has_swapped_edges()) {
 601       remove_flag(Node::Flag_has_swapped_edges);
 602     } else {
 603       add_flag(Node::Flag_has_swapped_edges);
 604     }
 605   }
 606 
 607   // Iterators over input Nodes for a Node X are written as:
 608   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 609   // NOTE: Required edges can contain embedded null pointers.
 610 
 611 //----------------- Other Node Properties
 612 
 613   // Generate class IDs for (some) ideal nodes so that it is possible to determine
 614   // the type of a node using a non-virtual method call (the method is_<Node>() below).
 615   //
 616   // A class ID of an ideal node is a set of bits. In a class ID, a single bit determines
 617   // the type of the node the ID represents; another subset of an ID's bits are reserved
 618   // for the superclasses of the node represented by the ID.
 619   //
 620   // By design, if A is a supertype of B, A.is_B() returns true and B.is_A()
 621   // returns false. A.is_A() returns true.
 622   //
 623   // If two classes, A and B, have the same superclass, a different bit of A's class id
 624   // is reserved for A's type than for B's type. That bit is specified by the third
 625   // parameter in the macro DEFINE_CLASS_ID.
 626   //
 627   // By convention, classes with deeper hierarchy are declared first. Moreover,
 628   // classes with the same hierarchy depth are sorted by usage frequency.
 629   //
 630   // The query method masks the bits to cut off bits of subclasses and then compares
 631   // the result with the class id (see the macro DEFINE_CLASS_QUERY below).
 632   //
 633   //  Class_MachCall=30, ClassMask_MachCall=31
 634   // 12               8               4               0
 635   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 636   //                                  |   |   |   |
 637   //                                  |   |   |   Bit_Mach=2
 638   //                                  |   |   Bit_MachReturn=4
 639   //                                  |   Bit_MachSafePoint=8
 640   //                                  Bit_MachCall=16
 641   //
 642   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 643   // 12               8               4               0
 644   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 645   //                              |   |   |
 646   //                              |   |   Bit_Region=8
 647   //                              |   Bit_Loop=16
 648   //                              Bit_CountedLoop=32
 649 
 650   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 651   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 652   Class_##cl = Class_##supcl + Bit_##cl , \
 653   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 654 
 655   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 656   // so that its values fit into 32 bits.
 657   enum NodeClasses {
 658     Bit_Node   = 0x00000000,
 659     Class_Node = 0x00000000,
 660     ClassMask_Node = 0xFFFFFFFF,
 661 
 662     DEFINE_CLASS_ID(Multi, Node, 0)
 663       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 664         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 665           DEFINE_CLASS_ID(CallJava,         Call, 0)
 666             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 667             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 668           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 669             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 670               DEFINE_CLASS_ID(CallLeafNoFP,     CallLeaf, 0)
 671           DEFINE_CLASS_ID(Allocate,         Call, 2)
 672             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 673           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 674             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 675             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 676           DEFINE_CLASS_ID(ArrayCopy,        Call, 4)
 677       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 678         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 679           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 680           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 681         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 682           DEFINE_CLASS_ID(BaseCountedLoopEnd,     If, 0)
 683             DEFINE_CLASS_ID(CountedLoopEnd,       BaseCountedLoopEnd, 0)
 684             DEFINE_CLASS_ID(LongCountedLoopEnd,   BaseCountedLoopEnd, 1)
 685           DEFINE_CLASS_ID(RangeCheck,             If, 1)
 686           DEFINE_CLASS_ID(OuterStripMinedLoopEnd, If, 2)
 687           DEFINE_CLASS_ID(ParsePredicate,         If, 3)
 688         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 689       DEFINE_CLASS_ID(Start,       Multi, 2)
 690       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 691         DEFINE_CLASS_ID(Initialize,       MemBar, 0)
 692         DEFINE_CLASS_ID(MemBarStoreStore, MemBar, 1)
 693 
 694     DEFINE_CLASS_ID(Mach,  Node, 1)
 695       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 696         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 697           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 698             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 699               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 700               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 701             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 702               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 703       DEFINE_CLASS_ID(MachBranch, Mach, 1)
 704         DEFINE_CLASS_ID(MachIf,         MachBranch, 0)
 705         DEFINE_CLASS_ID(MachGoto,       MachBranch, 1)
 706         DEFINE_CLASS_ID(MachNullCheck,  MachBranch, 2)
 707       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 2)
 708       DEFINE_CLASS_ID(MachTemp,         Mach, 3)
 709       DEFINE_CLASS_ID(MachConstantBase, Mach, 4)
 710       DEFINE_CLASS_ID(MachConstant,     Mach, 5)
 711         DEFINE_CLASS_ID(MachJump,       MachConstant, 0)
 712       DEFINE_CLASS_ID(MachMerge,        Mach, 6)
 713       DEFINE_CLASS_ID(MachMemBar,       Mach, 7)
 714 
 715     DEFINE_CLASS_ID(Type,  Node, 2)
 716       DEFINE_CLASS_ID(Phi,   Type, 0)
 717       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 718         DEFINE_CLASS_ID(CastII, ConstraintCast, 0)
 719         DEFINE_CLASS_ID(CheckCastPP, ConstraintCast, 1)
 720         DEFINE_CLASS_ID(CastLL, ConstraintCast, 2)
 721         DEFINE_CLASS_ID(CastFF, ConstraintCast, 3)
 722         DEFINE_CLASS_ID(CastDD, ConstraintCast, 4)
 723         DEFINE_CLASS_ID(CastVV, ConstraintCast, 5)
 724         DEFINE_CLASS_ID(CastPP, ConstraintCast, 6)
 725       DEFINE_CLASS_ID(CMove, Type, 3)
 726       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 727       DEFINE_CLASS_ID(DecodeNarrowPtr, Type, 5)
 728         DEFINE_CLASS_ID(DecodeN, DecodeNarrowPtr, 0)
 729         DEFINE_CLASS_ID(DecodeNKlass, DecodeNarrowPtr, 1)
 730       DEFINE_CLASS_ID(EncodeNarrowPtr, Type, 6)
 731         DEFINE_CLASS_ID(EncodeP, EncodeNarrowPtr, 0)
 732         DEFINE_CLASS_ID(EncodePKlass, EncodeNarrowPtr, 1)
 733       DEFINE_CLASS_ID(Vector, Type, 7)
 734         DEFINE_CLASS_ID(VectorMaskCmp, Vector, 0)
 735         DEFINE_CLASS_ID(VectorUnbox, Vector, 1)
 736         DEFINE_CLASS_ID(VectorReinterpret, Vector, 2)
 737         DEFINE_CLASS_ID(ShiftV, Vector, 3)
 738         DEFINE_CLASS_ID(CompressV, Vector, 4)
 739         DEFINE_CLASS_ID(ExpandV, Vector, 5)
 740         DEFINE_CLASS_ID(CompressM, Vector, 6)
 741         DEFINE_CLASS_ID(Reduction, Vector, 7)
 742         DEFINE_CLASS_ID(NegV, Vector, 8)
 743       DEFINE_CLASS_ID(Con, Type, 8)
 744           DEFINE_CLASS_ID(ConI, Con, 0)
 745       DEFINE_CLASS_ID(SafePointScalarMerge, Type, 9)
 746       DEFINE_CLASS_ID(Convert, Type, 10)
 747 
 748 
 749     DEFINE_CLASS_ID(Proj,  Node, 3)
 750       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 751       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 752       DEFINE_CLASS_ID(IfProj,    Proj, 2)
 753         DEFINE_CLASS_ID(IfTrue,    IfProj, 0)
 754         DEFINE_CLASS_ID(IfFalse,   IfProj, 1)
 755       DEFINE_CLASS_ID(Parm,      Proj, 4)
 756       DEFINE_CLASS_ID(MachProj,  Proj, 5)
 757 
 758     DEFINE_CLASS_ID(Mem, Node, 4)
 759       DEFINE_CLASS_ID(Load, Mem, 0)
 760         DEFINE_CLASS_ID(LoadVector,  Load, 0)
 761           DEFINE_CLASS_ID(LoadVectorGather, LoadVector, 0)
 762           DEFINE_CLASS_ID(LoadVectorGatherMasked, LoadVector, 1)
 763           DEFINE_CLASS_ID(LoadVectorMasked, LoadVector, 2)
 764       DEFINE_CLASS_ID(Store, Mem, 1)
 765         DEFINE_CLASS_ID(StoreVector, Store, 0)
 766           DEFINE_CLASS_ID(StoreVectorScatter, StoreVector, 0)
 767           DEFINE_CLASS_ID(StoreVectorScatterMasked, StoreVector, 1)
 768           DEFINE_CLASS_ID(StoreVectorMasked, StoreVector, 2)
 769       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 770         DEFINE_CLASS_ID(LoadStoreConditional, LoadStore, 0)
 771           DEFINE_CLASS_ID(CompareAndSwap, LoadStoreConditional, 0)
 772         DEFINE_CLASS_ID(CompareAndExchangeNode, LoadStore, 1)
 773 
 774     DEFINE_CLASS_ID(Region, Node, 5)
 775       DEFINE_CLASS_ID(Loop, Region, 0)
 776         DEFINE_CLASS_ID(Root,                Loop, 0)
 777         DEFINE_CLASS_ID(BaseCountedLoop,     Loop, 1)
 778           DEFINE_CLASS_ID(CountedLoop,       BaseCountedLoop, 0)
 779           DEFINE_CLASS_ID(LongCountedLoop,   BaseCountedLoop, 1)
 780         DEFINE_CLASS_ID(OuterStripMinedLoop, Loop, 2)
 781 
 782     DEFINE_CLASS_ID(Sub,   Node, 6)
 783       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 784         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
 785         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
 786         DEFINE_CLASS_ID(SubTypeCheck,Cmp, 2)
 787 
 788     DEFINE_CLASS_ID(MergeMem, Node, 7)
 789     DEFINE_CLASS_ID(Bool,     Node, 8)
 790     DEFINE_CLASS_ID(AddP,     Node, 9)
 791     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 792     DEFINE_CLASS_ID(Add,      Node, 11)
 793     DEFINE_CLASS_ID(Mul,      Node, 12)
 794     DEFINE_CLASS_ID(ClearArray, Node, 14)
 795     DEFINE_CLASS_ID(Halt,     Node, 15)
 796     DEFINE_CLASS_ID(Opaque1,  Node, 16)
 797       DEFINE_CLASS_ID(OpaqueLoopInit, Opaque1, 0)
 798       DEFINE_CLASS_ID(OpaqueLoopStride, Opaque1, 1)
 799     DEFINE_CLASS_ID(Opaque4,  Node, 17)
 800     DEFINE_CLASS_ID(OpaqueInitializedAssertionPredicate,  Node, 18)
 801     DEFINE_CLASS_ID(Move,     Node, 19)
 802     DEFINE_CLASS_ID(LShift,   Node, 20)
 803     DEFINE_CLASS_ID(Neg,      Node, 21)
 804 
 805     _max_classes  = ClassMask_Neg
 806   };
 807   #undef DEFINE_CLASS_ID
 808 
 809   // Flags are sorted by usage frequency.
 810   enum NodeFlags {
 811     Flag_is_Copy                     = 1 << 0, // should be first bit to avoid shift
 812     Flag_rematerialize               = 1 << 1,
 813     Flag_needs_anti_dependence_check = 1 << 2,
 814     Flag_is_macro                    = 1 << 3,
 815     Flag_is_Con                      = 1 << 4,
 816     Flag_is_cisc_alternate           = 1 << 5,
 817     Flag_is_dead_loop_safe           = 1 << 6,
 818     Flag_may_be_short_branch         = 1 << 7,
 819     Flag_avoid_back_to_back_before   = 1 << 8,
 820     Flag_avoid_back_to_back_after    = 1 << 9,
 821     Flag_has_call                    = 1 << 10,
 822     Flag_has_swapped_edges           = 1 << 11,
 823     Flag_is_scheduled                = 1 << 12,
 824     Flag_is_expensive                = 1 << 13,
 825     Flag_is_predicated_vector        = 1 << 14,
 826     Flag_for_post_loop_opts_igvn     = 1 << 15,
 827     Flag_is_removed_by_peephole      = 1 << 16,
 828     Flag_is_predicated_using_blend   = 1 << 17,
 829     _last_flag                       = Flag_is_predicated_using_blend
 830   };
 831 
 832   class PD;
 833 
 834 private:
 835   juint _class_id;
 836   juint _flags;
 837 
 838 #ifdef ASSERT
 839   static juint max_flags();
 840 #endif
 841 
 842 protected:
 843   // These methods should be called from constructors only.
 844   void init_class_id(juint c) {
 845     _class_id = c; // cast out const
 846   }
 847   void init_flags(uint fl) {
 848     assert(fl <= max_flags(), "invalid node flag");
 849     _flags |= fl;
 850   }
 851   void clear_flag(uint fl) {
 852     assert(fl <= max_flags(), "invalid node flag");
 853     _flags &= ~fl;
 854   }
 855 
 856 public:
 857   juint class_id() const { return _class_id; }
 858 
 859   juint flags() const { return _flags; }
 860 
 861   void add_flag(juint fl) { init_flags(fl); }
 862 
 863   void remove_flag(juint fl) { clear_flag(fl); }
 864 
 865   // Return a dense integer opcode number
 866   virtual int Opcode() const;
 867 
 868   // Virtual inherited Node size
 869   virtual uint size_of() const;
 870 
 871   // Other interesting Node properties
 872   #define DEFINE_CLASS_QUERY(type)                           \
 873   bool is_##type() const {                                   \
 874     return ((_class_id & ClassMask_##type) == Class_##type); \
 875   }                                                          \
 876   type##Node *as_##type() const {                            \
 877     assert(is_##type(), "invalid node class: %s", Name());   \
 878     return (type##Node*)this;                                \
 879   }                                                          \
 880   type##Node* isa_##type() const {                           \
 881     return (is_##type()) ? as_##type() : nullptr;            \
 882   }
 883 
 884   DEFINE_CLASS_QUERY(AbstractLock)
 885   DEFINE_CLASS_QUERY(Add)
 886   DEFINE_CLASS_QUERY(AddP)
 887   DEFINE_CLASS_QUERY(Allocate)
 888   DEFINE_CLASS_QUERY(AllocateArray)
 889   DEFINE_CLASS_QUERY(ArrayCopy)
 890   DEFINE_CLASS_QUERY(BaseCountedLoop)
 891   DEFINE_CLASS_QUERY(BaseCountedLoopEnd)
 892   DEFINE_CLASS_QUERY(Bool)
 893   DEFINE_CLASS_QUERY(BoxLock)
 894   DEFINE_CLASS_QUERY(Call)
 895   DEFINE_CLASS_QUERY(CallDynamicJava)
 896   DEFINE_CLASS_QUERY(CallJava)
 897   DEFINE_CLASS_QUERY(CallLeaf)
 898   DEFINE_CLASS_QUERY(CallLeafNoFP)
 899   DEFINE_CLASS_QUERY(CallRuntime)
 900   DEFINE_CLASS_QUERY(CallStaticJava)
 901   DEFINE_CLASS_QUERY(Catch)
 902   DEFINE_CLASS_QUERY(CatchProj)
 903   DEFINE_CLASS_QUERY(CheckCastPP)
 904   DEFINE_CLASS_QUERY(CastII)
 905   DEFINE_CLASS_QUERY(CastLL)
 906   DEFINE_CLASS_QUERY(ConI)
 907   DEFINE_CLASS_QUERY(CastPP)
 908   DEFINE_CLASS_QUERY(ConstraintCast)
 909   DEFINE_CLASS_QUERY(ClearArray)
 910   DEFINE_CLASS_QUERY(CMove)
 911   DEFINE_CLASS_QUERY(Cmp)
 912   DEFINE_CLASS_QUERY(Convert)
 913   DEFINE_CLASS_QUERY(CountedLoop)
 914   DEFINE_CLASS_QUERY(CountedLoopEnd)
 915   DEFINE_CLASS_QUERY(DecodeNarrowPtr)
 916   DEFINE_CLASS_QUERY(DecodeN)
 917   DEFINE_CLASS_QUERY(DecodeNKlass)
 918   DEFINE_CLASS_QUERY(EncodeNarrowPtr)
 919   DEFINE_CLASS_QUERY(EncodeP)
 920   DEFINE_CLASS_QUERY(EncodePKlass)
 921   DEFINE_CLASS_QUERY(FastLock)
 922   DEFINE_CLASS_QUERY(FastUnlock)
 923   DEFINE_CLASS_QUERY(Halt)
 924   DEFINE_CLASS_QUERY(If)
 925   DEFINE_CLASS_QUERY(RangeCheck)
 926   DEFINE_CLASS_QUERY(IfProj)
 927   DEFINE_CLASS_QUERY(IfFalse)
 928   DEFINE_CLASS_QUERY(IfTrue)
 929   DEFINE_CLASS_QUERY(Initialize)
 930   DEFINE_CLASS_QUERY(Jump)
 931   DEFINE_CLASS_QUERY(JumpProj)
 932   DEFINE_CLASS_QUERY(LongCountedLoop)
 933   DEFINE_CLASS_QUERY(LongCountedLoopEnd)
 934   DEFINE_CLASS_QUERY(Load)
 935   DEFINE_CLASS_QUERY(LoadStore)
 936   DEFINE_CLASS_QUERY(LoadStoreConditional)
 937   DEFINE_CLASS_QUERY(Lock)
 938   DEFINE_CLASS_QUERY(Loop)
 939   DEFINE_CLASS_QUERY(LShift)
 940   DEFINE_CLASS_QUERY(Mach)
 941   DEFINE_CLASS_QUERY(MachBranch)
 942   DEFINE_CLASS_QUERY(MachCall)
 943   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 944   DEFINE_CLASS_QUERY(MachCallJava)
 945   DEFINE_CLASS_QUERY(MachCallLeaf)
 946   DEFINE_CLASS_QUERY(MachCallRuntime)
 947   DEFINE_CLASS_QUERY(MachCallStaticJava)
 948   DEFINE_CLASS_QUERY(MachConstantBase)
 949   DEFINE_CLASS_QUERY(MachConstant)
 950   DEFINE_CLASS_QUERY(MachGoto)
 951   DEFINE_CLASS_QUERY(MachIf)
 952   DEFINE_CLASS_QUERY(MachJump)
 953   DEFINE_CLASS_QUERY(MachNullCheck)
 954   DEFINE_CLASS_QUERY(MachProj)
 955   DEFINE_CLASS_QUERY(MachReturn)
 956   DEFINE_CLASS_QUERY(MachSafePoint)
 957   DEFINE_CLASS_QUERY(MachSpillCopy)
 958   DEFINE_CLASS_QUERY(MachTemp)
 959   DEFINE_CLASS_QUERY(MachMemBar)
 960   DEFINE_CLASS_QUERY(MachMerge)
 961   DEFINE_CLASS_QUERY(Mem)
 962   DEFINE_CLASS_QUERY(MemBar)
 963   DEFINE_CLASS_QUERY(MemBarStoreStore)
 964   DEFINE_CLASS_QUERY(MergeMem)
 965   DEFINE_CLASS_QUERY(Move)
 966   DEFINE_CLASS_QUERY(Mul)
 967   DEFINE_CLASS_QUERY(Multi)
 968   DEFINE_CLASS_QUERY(MultiBranch)
 969   DEFINE_CLASS_QUERY(Neg)
 970   DEFINE_CLASS_QUERY(NegV)
 971   DEFINE_CLASS_QUERY(NeverBranch)
 972   DEFINE_CLASS_QUERY(Opaque1)
 973   DEFINE_CLASS_QUERY(Opaque4)
 974   DEFINE_CLASS_QUERY(OpaqueInitializedAssertionPredicate)
 975   DEFINE_CLASS_QUERY(OpaqueLoopInit)
 976   DEFINE_CLASS_QUERY(OpaqueLoopStride)
 977   DEFINE_CLASS_QUERY(OuterStripMinedLoop)
 978   DEFINE_CLASS_QUERY(OuterStripMinedLoopEnd)
 979   DEFINE_CLASS_QUERY(Parm)
 980   DEFINE_CLASS_QUERY(ParsePredicate)
 981   DEFINE_CLASS_QUERY(PCTable)
 982   DEFINE_CLASS_QUERY(Phi)
 983   DEFINE_CLASS_QUERY(Proj)
 984   DEFINE_CLASS_QUERY(Reduction)
 985   DEFINE_CLASS_QUERY(Region)
 986   DEFINE_CLASS_QUERY(Root)
 987   DEFINE_CLASS_QUERY(SafePoint)
 988   DEFINE_CLASS_QUERY(SafePointScalarObject)
 989   DEFINE_CLASS_QUERY(SafePointScalarMerge)
 990   DEFINE_CLASS_QUERY(Start)
 991   DEFINE_CLASS_QUERY(Store)
 992   DEFINE_CLASS_QUERY(Sub)
 993   DEFINE_CLASS_QUERY(SubTypeCheck)
 994   DEFINE_CLASS_QUERY(Type)
 995   DEFINE_CLASS_QUERY(Vector)
 996   DEFINE_CLASS_QUERY(VectorMaskCmp)
 997   DEFINE_CLASS_QUERY(VectorUnbox)
 998   DEFINE_CLASS_QUERY(VectorReinterpret)
 999   DEFINE_CLASS_QUERY(CompressV)
1000   DEFINE_CLASS_QUERY(ExpandV)
1001   DEFINE_CLASS_QUERY(CompressM)
1002   DEFINE_CLASS_QUERY(LoadVector)
1003   DEFINE_CLASS_QUERY(LoadVectorGather)
1004   DEFINE_CLASS_QUERY(LoadVectorMasked)
1005   DEFINE_CLASS_QUERY(LoadVectorGatherMasked)
1006   DEFINE_CLASS_QUERY(StoreVector)
1007   DEFINE_CLASS_QUERY(StoreVectorScatter)
1008   DEFINE_CLASS_QUERY(StoreVectorMasked)
1009   DEFINE_CLASS_QUERY(StoreVectorScatterMasked)
1010   DEFINE_CLASS_QUERY(ShiftV)
1011   DEFINE_CLASS_QUERY(Unlock)
1012 
1013   #undef DEFINE_CLASS_QUERY
1014 
1015   // duplicate of is_MachSpillCopy()
1016   bool is_SpillCopy () const {
1017     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
1018   }
1019 
1020   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
1021   // The data node which is safe to leave in dead loop during IGVN optimization.
1022   bool is_dead_loop_safe() const;
1023 
1024   // is_Copy() returns copied edge index (0 or 1)
1025   uint is_Copy() const { return (_flags & Flag_is_Copy); }
1026 
1027   virtual bool is_CFG() const { return false; }
1028 
1029   // If this node is control-dependent on a test, can it be
1030   // rerouted to a dominating equivalent test?  This is usually
1031   // true of non-CFG nodes, but can be false for operations which
1032   // depend for their correct sequencing on more than one test.
1033   // (In that case, hoisting to a dominating test may silently
1034   // skip some other important test.)
1035   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
1036 
1037   // When building basic blocks, I need to have a notion of block beginning
1038   // Nodes, next block selector Nodes (block enders), and next block
1039   // projections.  These calls need to work on their machine equivalents.  The
1040   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
1041   bool is_block_start() const {
1042     if ( is_Region() )
1043       return this == (const Node*)in(0);
1044     else
1045       return is_Start();
1046   }
1047 
1048   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
1049   // Goto and Return.  This call also returns the block ending Node.
1050   virtual const Node *is_block_proj() const;
1051 
1052   // The node is a "macro" node which needs to be expanded before matching
1053   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
1054   // The node is expensive: the best control is set during loop opts
1055   bool is_expensive() const { return (_flags & Flag_is_expensive) != 0 && in(0) != nullptr; }
1056   // The node's original edge position is swapped.
1057   bool has_swapped_edges() const { return (_flags & Flag_has_swapped_edges) != 0; }
1058 
1059   bool is_predicated_vector() const { return (_flags & Flag_is_predicated_vector) != 0; }
1060 
1061   bool is_predicated_using_blend() const { return (_flags & Flag_is_predicated_using_blend) != 0; }
1062 
1063   // Used in lcm to mark nodes that have scheduled
1064   bool is_scheduled() const { return (_flags & Flag_is_scheduled) != 0; }
1065 
1066   bool for_post_loop_opts_igvn() const { return (_flags & Flag_for_post_loop_opts_igvn) != 0; }
1067 
1068   // Is 'n' possibly a loop entry (i.e. a Parse Predicate projection)?
1069   static bool may_be_loop_entry(Node* n) {
1070     return n != nullptr && n->is_IfProj() && n->in(0)->is_ParsePredicate();
1071   }
1072 
1073 //----------------- Optimization
1074 
1075   // Get the worst-case Type output for this Node.
1076   virtual const class Type *bottom_type() const;
1077 
1078   // If we find a better type for a node, try to record it permanently.
1079   // Return true if this node actually changed.
1080   // Be sure to do the hash_delete game in the "rehash" variant.
1081   void raise_bottom_type(const Type* new_type);
1082 
1083   // Get the address type with which this node uses and/or defs memory,
1084   // or null if none.  The address type is conservatively wide.
1085   // Returns non-null for calls, membars, loads, stores, etc.
1086   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
1087   virtual const class TypePtr *adr_type() const { return nullptr; }
1088 
1089   // Return an existing node which computes the same function as this node.
1090   // The optimistic combined algorithm requires this to return a Node which
1091   // is a small number of steps away (e.g., one of my inputs).
1092   virtual Node* Identity(PhaseGVN* phase);
1093 
1094   // Return the set of values this Node can take on at runtime.
1095   virtual const Type* Value(PhaseGVN* phase) const;
1096 
1097   // Return a node which is more "ideal" than the current node.
1098   // The invariants on this call are subtle.  If in doubt, read the
1099   // treatise in node.cpp above the default implementation AND TEST WITH
1100   // -XX:VerifyIterativeGVN=1
1101   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1102 
1103   // Some nodes have specific Ideal subgraph transformations only if they are
1104   // unique users of specific nodes. Such nodes should be put on IGVN worklist
1105   // for the transformations to happen.
1106   bool has_special_unique_user() const;
1107 
1108   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1109   Node* find_exact_control(Node* ctrl);
1110 
1111   // Results of the dominance analysis.
1112   enum class DomResult {
1113     NotDominate,         // 'this' node does not dominate 'sub'.
1114     Dominate,            // 'this' node dominates or is equal to 'sub'.
1115     EncounteredDeadCode  // Result is undefined due to encountering dead code.
1116   };
1117   // Check if 'this' node dominates or equal to 'sub'.
1118   DomResult dominates(Node* sub, Node_List &nlist);
1119 
1120 protected:
1121   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
1122 public:
1123 
1124   // See if there is valid pipeline info
1125   static  const Pipeline *pipeline_class();
1126   virtual const Pipeline *pipeline() const;
1127 
1128   // Compute the latency from the def to this instruction of the ith input node
1129   uint latency(uint i);
1130 
1131   // Hash & compare functions, for pessimistic value numbering
1132 
1133   // If the hash function returns the special sentinel value NO_HASH,
1134   // the node is guaranteed never to compare equal to any other node.
1135   // If we accidentally generate a hash with value NO_HASH the node
1136   // won't go into the table and we'll lose a little optimization.
1137   static const uint NO_HASH = 0;
1138   virtual uint hash() const;
1139   virtual bool cmp( const Node &n ) const;
1140 
1141   // Operation appears to be iteratively computed (such as an induction variable)
1142   // It is possible for this operation to return false for a loop-varying
1143   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1144   bool is_iteratively_computed();
1145 
1146   // Determine if a node is a counted loop induction variable.
1147   // NOTE: The method is defined in "loopnode.cpp".
1148   bool is_cloop_ind_var() const;
1149 
1150   // Return a node with opcode "opc" and same inputs as "this" if one can
1151   // be found; Otherwise return null;
1152   Node* find_similar(int opc);
1153 
1154   // Return the unique control out if only one. Null if none or more than one.
1155   Node* unique_ctrl_out_or_null() const;
1156   // Return the unique control out. Asserts if none or more than one control out.
1157   Node* unique_ctrl_out() const;
1158 
1159   // Set control or add control as precedence edge
1160   void ensure_control_or_add_prec(Node* c);
1161 
1162   // Visit boundary uses of the node and apply a callback function for each.
1163   // Recursively traverse uses, stopping and applying the callback when
1164   // reaching a boundary node, defined by is_boundary. Note: the function
1165   // definition appears after the complete type definition of Node_List.
1166   template <typename Callback, typename Check>
1167   void visit_uses(Callback callback, Check is_boundary) const;
1168 
1169   // Returns a clone of the current node that's pinned (if the current node is not) for nodes found in array accesses
1170   // (Load and range check CastII nodes).
1171   // This is used when an array access is made dependent on 2 or more range checks (range check smearing or Loop Predication).
1172   virtual Node* pin_array_access_node() const {
1173     return nullptr;
1174   }
1175 
1176   //----------------- Code Generation
1177 
1178   // Ideal register class for Matching.  Zero means unmatched instruction
1179   // (these are cloned instead of converted to machine nodes).
1180   virtual uint ideal_reg() const;
1181 
1182   static const uint NotAMachineReg;   // must be > max. machine register
1183 
1184   // Do we Match on this edge index or not?  Generally false for Control
1185   // and true for everything else.  Weird for calls & returns.
1186   virtual uint match_edge(uint idx) const;
1187 
1188   // Register class output is returned in
1189   virtual const RegMask &out_RegMask() const;
1190   // Register class input is expected in
1191   virtual const RegMask &in_RegMask(uint) const;
1192   // Should we clone rather than spill this instruction?
1193   bool rematerialize() const;
1194 
1195   // Return JVM State Object if this Node carries debug info, or null otherwise
1196   virtual JVMState* jvms() const;
1197 
1198   // Print as assembly
1199   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
1200   // Emit bytes using C2_MacroAssembler
1201   virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const;
1202   // Size of instruction in bytes
1203   virtual uint size(PhaseRegAlloc *ra_) const;
1204 
1205   // Convenience function to extract an integer constant from a node.
1206   // If it is not an integer constant (either Con, CastII, or Mach),
1207   // return value_if_unknown.
1208   jint find_int_con(jint value_if_unknown) const {
1209     const TypeInt* t = find_int_type();
1210     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1211   }
1212   // Return the constant, knowing it is an integer constant already
1213   jint get_int() const {
1214     const TypeInt* t = find_int_type();
1215     guarantee(t != nullptr, "must be con");
1216     return t->get_con();
1217   }
1218   // Here's where the work is done.  Can produce non-constant int types too.
1219   const TypeInt* find_int_type() const;
1220   const TypeInteger* find_integer_type(BasicType bt) const;
1221 
1222   // Same thing for long (and intptr_t, via type.hpp):
1223   jlong get_long() const {
1224     const TypeLong* t = find_long_type();
1225     guarantee(t != nullptr, "must be con");
1226     return t->get_con();
1227   }
1228   jlong find_long_con(jint value_if_unknown) const {
1229     const TypeLong* t = find_long_type();
1230     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1231   }
1232   const TypeLong* find_long_type() const;
1233 
1234   jlong get_integer_as_long(BasicType bt) const {
1235     const TypeInteger* t = find_integer_type(bt);
1236     guarantee(t != nullptr && t->is_con(), "must be con");
1237     return t->get_con_as_long(bt);
1238   }
1239   jlong find_integer_as_long(BasicType bt, jlong value_if_unknown) const {
1240     const TypeInteger* t = find_integer_type(bt);
1241     if (t == nullptr || !t->is_con())  return value_if_unknown;
1242     return t->get_con_as_long(bt);
1243   }
1244   const TypePtr* get_ptr_type() const;
1245 
1246   // These guys are called by code generated by ADLC:
1247   intptr_t get_ptr() const;
1248   intptr_t get_narrowcon() const;
1249   jdouble getd() const;
1250   jfloat getf() const;
1251 
1252   // Nodes which are pinned into basic blocks
1253   virtual bool pinned() const { return false; }
1254 
1255   // Nodes which use memory without consuming it, hence need antidependences
1256   // More specifically, needs_anti_dependence_check returns true iff the node
1257   // (a) does a load, and (b) does not perform a store (except perhaps to a
1258   // stack slot or some other unaliased location).
1259   bool needs_anti_dependence_check() const;
1260 
1261   // Return which operand this instruction may cisc-spill. In other words,
1262   // return operand position that can convert from reg to memory access
1263   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
1264   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
1265 
1266   // Whether this is a memory-writing machine node.
1267   bool is_memory_writer() const { return is_Mach() && bottom_type()->has_memory(); }
1268 
1269   // Whether this is a memory phi node
1270   bool is_memory_phi() const { return is_Phi() && bottom_type() == Type::MEMORY; }
1271 
1272 //----------------- Printing, etc
1273 #ifndef PRODUCT
1274  public:
1275   Node* find(int idx, bool only_ctrl = false); // Search the graph for the given idx.
1276   Node* find_ctrl(int idx); // Search control ancestors for the given idx.
1277   void dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st) const;
1278   void dump_bfs(const int max_distance, Node* target, const char* options) const; // directly to tty
1279   void dump_bfs(const int max_distance) const; // dump_bfs(max_distance, nullptr, nullptr)
1280   class DumpConfig {
1281    public:
1282     // overridden to implement coloring of node idx
1283     virtual void pre_dump(outputStream *st, const Node* n) = 0;
1284     virtual void post_dump(outputStream *st) = 0;
1285   };
1286   void dump_idx(bool align = false, outputStream* st = tty, DumpConfig* dc = nullptr) const;
1287   void dump_name(outputStream* st = tty, DumpConfig* dc = nullptr) const;
1288   void dump() const; // print node with newline
1289   void dump(const char* suffix, bool mark = false, outputStream* st = tty, DumpConfig* dc = nullptr) const; // Print this node.
1290   void dump(int depth) const;        // Print this node, recursively to depth d
1291   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
1292   void dump_comp() const;            // Print this node in compact representation.
1293   // Print this node in compact representation.
1294   void dump_comp(const char* suffix, outputStream *st = tty) const;
1295  private:
1296   virtual void dump_req(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print required-edge info
1297   virtual void dump_prec(outputStream* st = tty, DumpConfig* dc = nullptr) const;   // Print precedence-edge info
1298   virtual void dump_out(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print the output edge info
1299  public:
1300   virtual void dump_spec(outputStream *st) const {};      // Print per-node info
1301   // Print compact per-node info
1302   virtual void dump_compact_spec(outputStream *st) const { dump_spec(st); }
1303 
1304   static void verify(int verify_depth, VectorSet& visited, Node_List& worklist);
1305 
1306   // This call defines a class-unique string used to identify class instances
1307   virtual const char *Name() const;
1308 
1309   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1310   static bool in_dump() { return Compile::current()->_in_dump_cnt > 0; } // check if we are in a dump call
1311 #endif
1312 #ifdef ASSERT
1313   void verify_construction();
1314   bool verify_jvms(const JVMState* jvms) const;
1315 
1316   Node* _debug_orig;                   // Original version of this, if any.
1317   Node*  debug_orig() const            { return _debug_orig; }
1318   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1319   void   dump_orig(outputStream *st, bool print_key = true) const;
1320 
1321   uint64_t _debug_idx;                 // Unique value assigned to every node.
1322   uint64_t debug_idx() const           { return _debug_idx; }
1323   void set_debug_idx(uint64_t debug_idx) { _debug_idx = debug_idx; }
1324 
1325   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1326   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1327   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1328 
1329   static void init_NodeProperty();
1330 
1331   #if OPTO_DU_ITERATOR_ASSERT
1332   const Node* _last_del;               // The last deleted node.
1333   uint        _del_tick;               // Bumped when a deletion happens..
1334   #endif
1335 #endif
1336 };
1337 
1338 inline bool not_a_node(const Node* n) {
1339   if (n == nullptr)                return true;
1340   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
1341   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
1342   return false;
1343 }
1344 
1345 //-----------------------------------------------------------------------------
1346 // Iterators over DU info, and associated Node functions.
1347 
1348 #if OPTO_DU_ITERATOR_ASSERT
1349 
1350 // Common code for assertion checking on DU iterators.
1351 class DUIterator_Common {
1352 #ifdef ASSERT
1353  protected:
1354   bool         _vdui;               // cached value of VerifyDUIterators
1355   const Node*  _node;               // the node containing the _out array
1356   uint         _outcnt;             // cached node->_outcnt
1357   uint         _del_tick;           // cached node->_del_tick
1358   Node*        _last;               // last value produced by the iterator
1359 
1360   void sample(const Node* node);    // used by c'tor to set up for verifies
1361   void verify(const Node* node, bool at_end_ok = false);
1362   void verify_resync();
1363   void reset(const DUIterator_Common& that);
1364 
1365 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1366   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1367 #else
1368   #define I_VDUI_ONLY(i,x) { }
1369 #endif //ASSERT
1370 };
1371 
1372 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1373 
1374 // Default DU iterator.  Allows appends onto the out array.
1375 // Allows deletion from the out array only at the current point.
1376 // Usage:
1377 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1378 //    Node* y = x->out(i);
1379 //    ...
1380 //  }
1381 // Compiles in product mode to a unsigned integer index, which indexes
1382 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1383 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1384 // before continuing the loop.  You must delete only the last-produced
1385 // edge.  You must delete only a single copy of the last-produced edge,
1386 // or else you must delete all copies at once (the first time the edge
1387 // is produced by the iterator).
1388 class DUIterator : public DUIterator_Common {
1389   friend class Node;
1390 
1391   // This is the index which provides the product-mode behavior.
1392   // Whatever the product-mode version of the system does to the
1393   // DUI index is done to this index.  All other fields in
1394   // this class are used only for assertion checking.
1395   uint         _idx;
1396 
1397   #ifdef ASSERT
1398   uint         _refresh_tick;    // Records the refresh activity.
1399 
1400   void sample(const Node* node); // Initialize _refresh_tick etc.
1401   void verify(const Node* node, bool at_end_ok = false);
1402   void verify_increment();       // Verify an increment operation.
1403   void verify_resync();          // Verify that we can back up over a deletion.
1404   void verify_finish();          // Verify that the loop terminated properly.
1405   void refresh();                // Resample verification info.
1406   void reset(const DUIterator& that);  // Resample after assignment.
1407   #endif
1408 
1409   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1410     { _idx = 0;                         debug_only(sample(node)); }
1411 
1412  public:
1413   // initialize to garbage; clear _vdui to disable asserts
1414   DUIterator()
1415     { /*initialize to garbage*/         debug_only(_vdui = false); }
1416 
1417   DUIterator(const DUIterator& that)
1418     { _idx = that._idx;                 debug_only(_vdui = false; reset(that)); }
1419 
1420   void operator++(int dummy_to_specify_postfix_op)
1421     { _idx++;                           VDUI_ONLY(verify_increment()); }
1422 
1423   void operator--()
1424     { VDUI_ONLY(verify_resync());       --_idx; }
1425 
1426   ~DUIterator()
1427     { VDUI_ONLY(verify_finish()); }
1428 
1429   void operator=(const DUIterator& that)
1430     { _idx = that._idx;                 debug_only(reset(that)); }
1431 };
1432 
1433 DUIterator Node::outs() const
1434   { return DUIterator(this, 0); }
1435 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1436   { I_VDUI_ONLY(i, i.refresh());        return i; }
1437 bool Node::has_out(DUIterator& i) const
1438   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1439 Node*    Node::out(DUIterator& i) const
1440   { I_VDUI_ONLY(i, i.verify(this));     return debug_only(i._last=) _out[i._idx]; }
1441 
1442 
1443 // Faster DU iterator.  Disallows insertions into the out array.
1444 // Allows deletion from the out array only at the current point.
1445 // Usage:
1446 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1447 //    Node* y = x->fast_out(i);
1448 //    ...
1449 //  }
1450 // Compiles in product mode to raw Node** pointer arithmetic, with
1451 // no reloading of pointers from the original node x.  If you delete,
1452 // you must perform "--i; --imax" just before continuing the loop.
1453 // If you delete multiple copies of the same edge, you must decrement
1454 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1455 class DUIterator_Fast : public DUIterator_Common {
1456   friend class Node;
1457   friend class DUIterator_Last;
1458 
1459   // This is the pointer which provides the product-mode behavior.
1460   // Whatever the product-mode version of the system does to the
1461   // DUI pointer is done to this pointer.  All other fields in
1462   // this class are used only for assertion checking.
1463   Node**       _outp;
1464 
1465   #ifdef ASSERT
1466   void verify(const Node* node, bool at_end_ok = false);
1467   void verify_limit();
1468   void verify_resync();
1469   void verify_relimit(uint n);
1470   void reset(const DUIterator_Fast& that);
1471   #endif
1472 
1473   // Note:  offset must be signed, since -1 is sometimes passed
1474   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1475     { _outp = node->_out + offset;      debug_only(sample(node)); }
1476 
1477  public:
1478   // initialize to garbage; clear _vdui to disable asserts
1479   DUIterator_Fast()
1480     { /*initialize to garbage*/         debug_only(_vdui = false); }
1481 
1482   DUIterator_Fast(const DUIterator_Fast& that)
1483     { _outp = that._outp;               debug_only(_vdui = false; reset(that)); }
1484 
1485   void operator++(int dummy_to_specify_postfix_op)
1486     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1487 
1488   void operator--()
1489     { VDUI_ONLY(verify_resync());       --_outp; }
1490 
1491   void operator-=(uint n)   // applied to the limit only
1492     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1493 
1494   bool operator<(DUIterator_Fast& limit) {
1495     I_VDUI_ONLY(*this, this->verify(_node, true));
1496     I_VDUI_ONLY(limit, limit.verify_limit());
1497     return _outp < limit._outp;
1498   }
1499 
1500   void operator=(const DUIterator_Fast& that)
1501     { _outp = that._outp;               debug_only(reset(that)); }
1502 };
1503 
1504 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1505   // Assign a limit pointer to the reference argument:
1506   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1507   // Return the base pointer:
1508   return DUIterator_Fast(this, 0);
1509 }
1510 Node* Node::fast_out(DUIterator_Fast& i) const {
1511   I_VDUI_ONLY(i, i.verify(this));
1512   return debug_only(i._last=) *i._outp;
1513 }
1514 
1515 
1516 // Faster DU iterator.  Requires each successive edge to be removed.
1517 // Does not allow insertion of any edges.
1518 // Usage:
1519 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1520 //    Node* y = x->last_out(i);
1521 //    ...
1522 //  }
1523 // Compiles in product mode to raw Node** pointer arithmetic, with
1524 // no reloading of pointers from the original node x.
1525 class DUIterator_Last : private DUIterator_Fast {
1526   friend class Node;
1527 
1528   #ifdef ASSERT
1529   void verify(const Node* node, bool at_end_ok = false);
1530   void verify_limit();
1531   void verify_step(uint num_edges);
1532   #endif
1533 
1534   // Note:  offset must be signed, since -1 is sometimes passed
1535   DUIterator_Last(const Node* node, ptrdiff_t offset)
1536     : DUIterator_Fast(node, offset) { }
1537 
1538   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1539   void operator<(int)                              {} // do not use
1540 
1541  public:
1542   DUIterator_Last() { }
1543   // initialize to garbage
1544 
1545   DUIterator_Last(const DUIterator_Last& that) = default;
1546 
1547   void operator--()
1548     { _outp--;              VDUI_ONLY(verify_step(1));  }
1549 
1550   void operator-=(uint n)
1551     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1552 
1553   bool operator>=(DUIterator_Last& limit) {
1554     I_VDUI_ONLY(*this, this->verify(_node, true));
1555     I_VDUI_ONLY(limit, limit.verify_limit());
1556     return _outp >= limit._outp;
1557   }
1558 
1559   DUIterator_Last& operator=(const DUIterator_Last& that) = default;
1560 };
1561 
1562 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1563   // Assign a limit pointer to the reference argument:
1564   imin = DUIterator_Last(this, 0);
1565   // Return the initial pointer:
1566   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1567 }
1568 Node* Node::last_out(DUIterator_Last& i) const {
1569   I_VDUI_ONLY(i, i.verify(this));
1570   return debug_only(i._last=) *i._outp;
1571 }
1572 
1573 #endif //OPTO_DU_ITERATOR_ASSERT
1574 
1575 #undef I_VDUI_ONLY
1576 #undef VDUI_ONLY
1577 
1578 // An Iterator that truly follows the iterator pattern.  Doesn't
1579 // support deletion but could be made to.
1580 //
1581 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1582 //     Node* m = i.get();
1583 //
1584 class SimpleDUIterator : public StackObj {
1585  private:
1586   Node* node;
1587   DUIterator_Fast imax;
1588   DUIterator_Fast i;
1589  public:
1590   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1591   bool has_next() { return i < imax; }
1592   void next() { i++; }
1593   Node* get() { return node->fast_out(i); }
1594 };
1595 
1596 
1597 //-----------------------------------------------------------------------------
1598 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1599 // Abstractly provides an infinite array of Node*'s, initialized to null.
1600 // Note that the constructor just zeros things, and since I use Arena
1601 // allocation I do not need a destructor to reclaim storage.
1602 class Node_Array : public AnyObj {
1603   friend class VMStructs;
1604 protected:
1605   Arena* _a;                    // Arena to allocate in
1606   uint   _max;
1607   Node** _nodes;
1608   ReallocMark _nesting;         // Safety checks for arena reallocation
1609 
1610   void   grow( uint i );        // Grow array node to fit
1611 public:
1612   Node_Array(Arena* a, uint max = OptoNodeListSize) : _a(a), _max(max) {
1613     _nodes = NEW_ARENA_ARRAY(a, Node*, max);
1614     clear();
1615   }
1616   Node_Array() : Node_Array(Thread::current()->resource_area()) {}
1617 
1618   NONCOPYABLE(Node_Array);
1619   Node_Array& operator=(Node_Array&&) = delete;
1620   // Allow move constructor for && (eg. capture return of function)
1621   Node_Array(Node_Array&&) = default;
1622 
1623   Node *operator[] ( uint i ) const // Lookup, or null for not mapped
1624   { return (i<_max) ? _nodes[i] : (Node*)nullptr; }
1625   Node* at(uint i) const { assert(i<_max,"oob"); return _nodes[i]; }
1626   Node** adr() { return _nodes; }
1627   // Extend the mapping: index i maps to Node *n.
1628   void map( uint i, Node *n ) { grow(i); _nodes[i] = n; }
1629   void insert( uint i, Node *n );
1630   void remove( uint i );        // Remove, preserving order
1631   // Clear all entries in _nodes to null but keep storage
1632   void clear() {
1633     Copy::zero_to_bytes(_nodes, _max * sizeof(Node*));
1634   }
1635 
1636   uint max() const { return _max; }
1637   void dump() const;
1638 };
1639 
1640 class Node_List : public Node_Array {
1641   friend class VMStructs;
1642   uint _cnt;
1643 public:
1644   Node_List(uint max = OptoNodeListSize) : Node_Array(Thread::current()->resource_area(), max), _cnt(0) {}
1645   Node_List(Arena *a, uint max = OptoNodeListSize) : Node_Array(a, max), _cnt(0) {}
1646 
1647   NONCOPYABLE(Node_List);
1648   Node_List& operator=(Node_List&&) = delete;
1649   // Allow move constructor for && (eg. capture return of function)
1650   Node_List(Node_List&&) = default;
1651 
1652   bool contains(const Node* n) const {
1653     for (uint e = 0; e < size(); e++) {
1654       if (at(e) == n) return true;
1655     }
1656     return false;
1657   }
1658   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1659   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1660   void push( Node *b ) { map(_cnt++,b); }
1661   void yank( Node *n );         // Find and remove
1662   Node *pop() { return _nodes[--_cnt]; }
1663   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1664   void copy(const Node_List& from) {
1665     if (from._max > _max) {
1666       grow(from._max);
1667     }
1668     _cnt = from._cnt;
1669     Copy::conjoint_words_to_higher((HeapWord*)&from._nodes[0], (HeapWord*)&_nodes[0], from._max * sizeof(Node*));
1670   }
1671 
1672   uint size() const { return _cnt; }
1673   void dump() const;
1674   void dump_simple() const;
1675 };
1676 
1677 // Definition must appear after complete type definition of Node_List
1678 template <typename Callback, typename Check>
1679 void Node::visit_uses(Callback callback, Check is_boundary) const {
1680   ResourceMark rm;
1681   VectorSet visited;
1682   Node_List worklist;
1683 
1684   // The initial worklist consists of the direct uses
1685   for (DUIterator_Fast kmax, k = fast_outs(kmax); k < kmax; k++) {
1686     Node* out = fast_out(k);
1687     if (!visited.test_set(out->_idx)) { worklist.push(out); }
1688   }
1689 
1690   while (worklist.size() > 0) {
1691     Node* use = worklist.pop();
1692     // Apply callback on boundary nodes
1693     if (is_boundary(use)) {
1694       callback(use);
1695     } else {
1696       // Not a boundary node, continue search
1697       for (DUIterator_Fast kmax, k = use->fast_outs(kmax); k < kmax; k++) {
1698         Node* out = use->fast_out(k);
1699         if (!visited.test_set(out->_idx)) { worklist.push(out); }
1700       }
1701     }
1702   }
1703 }
1704 
1705 
1706 //------------------------------Unique_Node_List-------------------------------
1707 class Unique_Node_List : public Node_List {
1708   friend class VMStructs;
1709   VectorSet _in_worklist;
1710   uint _clock_index;            // Index in list where to pop from next
1711 public:
1712   Unique_Node_List() : Node_List(), _clock_index(0) {}
1713   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1714 
1715   NONCOPYABLE(Unique_Node_List);
1716   Unique_Node_List& operator=(Unique_Node_List&&) = delete;
1717   // Allow move constructor for && (eg. capture return of function)
1718   Unique_Node_List(Unique_Node_List&&) = default;
1719 
1720   void remove( Node *n );
1721   bool member( Node *n ) { return _in_worklist.test(n->_idx) != 0; }
1722   VectorSet& member_set(){ return _in_worklist; }
1723 
1724   void push(Node* b) {
1725     if( !_in_worklist.test_set(b->_idx) )
1726       Node_List::push(b);
1727   }
1728   void push_non_cfg_inputs_of(const Node* node) {
1729     for (uint i = 1; i < node->req(); i++) {
1730       Node* input = node->in(i);
1731       if (input != nullptr && !input->is_CFG()) {
1732         push(input);
1733       }
1734     }
1735   }
1736 
1737   void push_outputs_of(const Node* node) {
1738     for (DUIterator_Fast imax, i = node->fast_outs(imax); i < imax; i++) {
1739       Node* output = node->fast_out(i);
1740       push(output);
1741     }
1742   }
1743 
1744   Node *pop() {
1745     if( _clock_index >= size() ) _clock_index = 0;
1746     Node *b = at(_clock_index);
1747     map( _clock_index, Node_List::pop());
1748     if (size() != 0) _clock_index++; // Always start from 0
1749     _in_worklist.remove(b->_idx);
1750     return b;
1751   }
1752   Node *remove(uint i) {
1753     Node *b = Node_List::at(i);
1754     _in_worklist.remove(b->_idx);
1755     map(i,Node_List::pop());
1756     return b;
1757   }
1758   void yank(Node *n) {
1759     _in_worklist.remove(n->_idx);
1760     Node_List::yank(n);
1761   }
1762   void  clear() {
1763     _in_worklist.clear();        // Discards storage but grows automatically
1764     Node_List::clear();
1765     _clock_index = 0;
1766   }
1767   void ensure_empty() {
1768     assert(size() == 0, "must be empty");
1769     clear(); // just in case
1770   }
1771 
1772   // Used after parsing to remove useless nodes before Iterative GVN
1773   void remove_useless_nodes(VectorSet& useful);
1774 
1775   // If the idx of the Nodes change, we must recompute the VectorSet
1776   void recompute_idx_set() {
1777     _in_worklist.clear();
1778     for (uint i = 0; i < size(); i++) {
1779       Node* n = at(i);
1780       _in_worklist.set(n->_idx);
1781     }
1782   }
1783 
1784 #ifdef ASSERT
1785   bool is_subset_of(Unique_Node_List& other) {
1786     for (uint i = 0; i < size(); i++) {
1787       Node* n = at(i);
1788       if (!other.member(n)) {
1789         return false;
1790       }
1791     }
1792     return true;
1793   }
1794 #endif
1795 
1796   bool contains(const Node* n) const {
1797     fatal("use faster member() instead");
1798     return false;
1799   }
1800 
1801 #ifndef PRODUCT
1802   void print_set() const { _in_worklist.print(); }
1803 #endif
1804 };
1805 
1806 // Unique_Mixed_Node_List
1807 // unique: nodes are added only once
1808 // mixed: allow new and old nodes
1809 class Unique_Mixed_Node_List : public ResourceObj {
1810 public:
1811   Unique_Mixed_Node_List() : _visited_set(cmpkey, hashkey) {}
1812 
1813   void add(Node* node) {
1814     if (not_a_node(node)) {
1815       return; // Gracefully handle null, -1, 0xabababab, etc.
1816     }
1817     if (_visited_set[node] == nullptr) {
1818       _visited_set.Insert(node, node);
1819       _worklist.push(node);
1820     }
1821   }
1822 
1823   Node* operator[] (uint i) const {
1824     return _worklist[i];
1825   }
1826 
1827   size_t size() {
1828     return _worklist.size();
1829   }
1830 
1831 private:
1832   Dict _visited_set;
1833   Node_List _worklist;
1834 };
1835 
1836 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1837 inline void Compile::record_for_igvn(Node* n) {
1838   _igvn_worklist->push(n);
1839 }
1840 
1841 // Inline definition of Compile::remove_for_igvn must be deferred to this point.
1842 inline void Compile::remove_for_igvn(Node* n) {
1843   _igvn_worklist->remove(n);
1844 }
1845 
1846 //------------------------------Node_Stack-------------------------------------
1847 class Node_Stack {
1848   friend class VMStructs;
1849 protected:
1850   struct INode {
1851     Node *node; // Processed node
1852     uint  indx; // Index of next node's child
1853   };
1854   INode *_inode_top; // tos, stack grows up
1855   INode *_inode_max; // End of _inodes == _inodes + _max
1856   INode *_inodes;    // Array storage for the stack
1857   Arena *_a;         // Arena to allocate in
1858   ReallocMark _nesting; // Safety checks for arena reallocation
1859   void grow();
1860 public:
1861   Node_Stack(int size) {
1862     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1863     _a = Thread::current()->resource_area();
1864     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1865     _inode_max = _inodes + max;
1866     _inode_top = _inodes - 1; // stack is empty
1867   }
1868 
1869   Node_Stack(Arena *a, int size) : _a(a) {
1870     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1871     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1872     _inode_max = _inodes + max;
1873     _inode_top = _inodes - 1; // stack is empty
1874   }
1875 
1876   void pop() {
1877     assert(_inode_top >= _inodes, "node stack underflow");
1878     --_inode_top;
1879   }
1880   void push(Node *n, uint i) {
1881     ++_inode_top;
1882     grow();
1883     INode *top = _inode_top; // optimization
1884     top->node = n;
1885     top->indx = i;
1886   }
1887   Node *node() const {
1888     return _inode_top->node;
1889   }
1890   Node* node_at(uint i) const {
1891     assert(_inodes + i <= _inode_top, "in range");
1892     return _inodes[i].node;
1893   }
1894   uint index() const {
1895     return _inode_top->indx;
1896   }
1897   uint index_at(uint i) const {
1898     assert(_inodes + i <= _inode_top, "in range");
1899     return _inodes[i].indx;
1900   }
1901   void set_node(Node *n) {
1902     _inode_top->node = n;
1903   }
1904   void set_index(uint i) {
1905     _inode_top->indx = i;
1906   }
1907   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1908   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1909   bool is_nonempty() const { return (_inode_top >= _inodes); }
1910   bool is_empty() const { return (_inode_top < _inodes); }
1911   void clear() { _inode_top = _inodes - 1; } // retain storage
1912 
1913   // Node_Stack is used to map nodes.
1914   Node* find(uint idx) const;
1915 
1916   NONCOPYABLE(Node_Stack);
1917 };
1918 
1919 
1920 //-----------------------------Node_Notes--------------------------------------
1921 // Debugging or profiling annotations loosely and sparsely associated
1922 // with some nodes.  See Compile::node_notes_at for the accessor.
1923 class Node_Notes {
1924   friend class VMStructs;
1925   JVMState* _jvms;
1926 
1927 public:
1928   Node_Notes(JVMState* jvms = nullptr) {
1929     _jvms = jvms;
1930   }
1931 
1932   JVMState* jvms()            { return _jvms; }
1933   void  set_jvms(JVMState* x) {        _jvms = x; }
1934 
1935   // True if there is nothing here.
1936   bool is_clear() {
1937     return (_jvms == nullptr);
1938   }
1939 
1940   // Make there be nothing here.
1941   void clear() {
1942     _jvms = nullptr;
1943   }
1944 
1945   // Make a new, clean node notes.
1946   static Node_Notes* make(Compile* C) {
1947     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1948     nn->clear();
1949     return nn;
1950   }
1951 
1952   Node_Notes* clone(Compile* C) {
1953     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1954     (*nn) = (*this);
1955     return nn;
1956   }
1957 
1958   // Absorb any information from source.
1959   bool update_from(Node_Notes* source) {
1960     bool changed = false;
1961     if (source != nullptr) {
1962       if (source->jvms() != nullptr) {
1963         set_jvms(source->jvms());
1964         changed = true;
1965       }
1966     }
1967     return changed;
1968   }
1969 };
1970 
1971 // Inlined accessors for Compile::node_nodes that require the preceding class:
1972 inline Node_Notes*
1973 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
1974                            int idx, bool can_grow) {
1975   assert(idx >= 0, "oob");
1976   int block_idx = (idx >> _log2_node_notes_block_size);
1977   int grow_by = (block_idx - (arr == nullptr? 0: arr->length()));
1978   if (grow_by >= 0) {
1979     if (!can_grow) return nullptr;
1980     grow_node_notes(arr, grow_by + 1);
1981   }
1982   if (arr == nullptr) return nullptr;
1983   // (Every element of arr is a sub-array of length _node_notes_block_size.)
1984   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
1985 }
1986 
1987 inline bool
1988 Compile::set_node_notes_at(int idx, Node_Notes* value) {
1989   if (value == nullptr || value->is_clear())
1990     return false;  // nothing to write => write nothing
1991   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
1992   assert(loc != nullptr, "");
1993   return loc->update_from(value);
1994 }
1995 
1996 
1997 //------------------------------TypeNode---------------------------------------
1998 // Node with a Type constant.
1999 class TypeNode : public Node {
2000 protected:
2001   virtual uint hash() const;    // Check the type
2002   virtual bool cmp( const Node &n ) const;
2003   virtual uint size_of() const; // Size is bigger
2004   const Type* const _type;
2005 public:
2006   void set_type(const Type* t) {
2007     assert(t != nullptr, "sanity");
2008     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
2009     *(const Type**)&_type = t;   // cast away const-ness
2010     // If this node is in the hash table, make sure it doesn't need a rehash.
2011     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
2012   }
2013   const Type* type() const { assert(_type != nullptr, "sanity"); return _type; };
2014   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
2015     init_class_id(Class_Type);
2016   }
2017   virtual const Type* Value(PhaseGVN* phase) const;
2018   virtual const Type *bottom_type() const;
2019   virtual       uint  ideal_reg() const;
2020 #ifndef PRODUCT
2021   virtual void dump_spec(outputStream *st) const;
2022   virtual void dump_compact_spec(outputStream *st) const;
2023 #endif
2024 };
2025 
2026 #include "opto/opcodes.hpp"
2027 
2028 #define Op_IL(op) \
2029   inline int Op_ ## op(BasicType bt) { \
2030   assert(bt == T_INT || bt == T_LONG, "only for int or longs"); \
2031   if (bt == T_INT) { \
2032     return Op_## op ## I; \
2033   } \
2034   return Op_## op ## L; \
2035 }
2036 
2037 Op_IL(Add)
2038 Op_IL(Sub)
2039 Op_IL(Mul)
2040 Op_IL(URShift)
2041 Op_IL(LShift)
2042 Op_IL(Xor)
2043 Op_IL(Cmp)
2044 
2045 inline int Op_ConIL(BasicType bt) {
2046   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2047   if (bt == T_INT) {
2048     return Op_ConI;
2049   }
2050   return Op_ConL;
2051 }
2052 
2053 inline int Op_Cmp_unsigned(BasicType bt) {
2054   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2055   if (bt == T_INT) {
2056     return Op_CmpU;
2057   }
2058   return Op_CmpUL;
2059 }
2060 
2061 inline int Op_Cast(BasicType bt) {
2062   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2063   if (bt == T_INT) {
2064     return Op_CastII;
2065   }
2066   return Op_CastLL;
2067 }
2068 
2069 #endif // SHARE_OPTO_NODE_HPP