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