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