1 /*
   2  * Copyright (c) 1997, 2013, 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_VM_OPTO_NODE_HPP
  26 #define SHARE_VM_OPTO_NODE_HPP
  27 
  28 #include "libadt/port.hpp"
  29 #include "libadt/vectset.hpp"
  30 #include "opto/compile.hpp"
  31 #include "opto/type.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 Block;
  45 class BoolNode;
  46 class BoxLockNode;
  47 class CMoveNode;
  48 class CallDynamicJavaNode;
  49 class CallJavaNode;
  50 class CallLeafNode;
  51 class CallNode;
  52 class CallRuntimeNode;
  53 class CallStaticJavaNode;
  54 class CatchNode;
  55 class CatchProjNode;
  56 class CheckCastPPNode;
  57 class CastIINode;
  58 class ClearArrayNode;
  59 class CmpNode;
  60 class CodeBuffer;
  61 class ConstraintCastNode;
  62 class ConNode;
  63 class CountedLoopNode;
  64 class CountedLoopEndNode;
  65 class DecodeNarrowPtrNode;
  66 class DecodeNNode;
  67 class DecodeNKlassNode;
  68 class EncodeNarrowPtrNode;
  69 class EncodePNode;
  70 class EncodePKlassNode;
  71 class FastLockNode;
  72 class FastUnlockNode;
  73 class IfNode;
  74 class IfFalseNode;
  75 class IfTrueNode;
  76 class InitializeNode;
  77 class JVMState;
  78 class JumpNode;
  79 class JumpProjNode;
  80 class LoadNode;
  81 class LoadStoreNode;
  82 class LockNode;
  83 class LoopNode;
  84 class MachBranchNode;
  85 class MachCallDynamicJavaNode;
  86 class MachCallJavaNode;
  87 class MachCallLeafNode;
  88 class MachCallNode;
  89 class MachCallRuntimeNode;
  90 class MachCallStaticJavaNode;
  91 class MachConstantBaseNode;
  92 class MachConstantNode;
  93 class MachGotoNode;
  94 class MachIfNode;
  95 class MachNode;
  96 class MachNullCheckNode;
  97 class MachProjNode;
  98 class MachReturnNode;
  99 class MachSafePointNode;
 100 class MachSpillCopyNode;
 101 class MachTempNode;
 102 class MachMergeNode;
 103 class Matcher;
 104 class MemBarNode;
 105 class MemBarStoreStoreNode;
 106 class MemNode;
 107 class MergeMemNode;
 108 class MulNode;
 109 class MultiNode;
 110 class MultiBranchNode;
 111 class NeverBranchNode;
 112 class Node;
 113 class Node_Array;
 114 class Node_List;
 115 class Node_Stack;
 116 class NullCheckNode;
 117 class OopMap;
 118 class ParmNode;
 119 class PCTableNode;
 120 class PhaseCCP;
 121 class PhaseGVN;
 122 class PhaseIterGVN;
 123 class PhaseRegAlloc;
 124 class PhaseTransform;
 125 class PhaseValues;
 126 class PhiNode;
 127 class Pipeline;
 128 class ProjNode;
 129 class RegMask;
 130 class RegionNode;
 131 class RootNode;
 132 class SafePointNode;
 133 class SafePointScalarObjectNode;
 134 class StartNode;
 135 class State;
 136 class StoreNode;
 137 class SubNode;
 138 class Type;
 139 class TypeNode;
 140 class UnlockNode;
 141 class VectorNode;
 142 class LoadVectorNode;
 143 class StoreVectorNode;
 144 class VectorSet;
 145 typedef void (*NFunc)(Node&,void*);
 146 extern "C" {
 147   typedef int (*C_sort_func_t)(const void *, const void *);
 148 }
 149 
 150 // The type of all node counts and indexes.
 151 // It must hold at least 16 bits, but must also be fast to load and store.
 152 // This type, if less than 32 bits, could limit the number of possible nodes.
 153 // (To make this type platform-specific, move to globalDefinitions_xxx.hpp.)
 154 typedef unsigned int node_idx_t;
 155 
 156 
 157 #ifndef OPTO_DU_ITERATOR_ASSERT
 158 #ifdef ASSERT
 159 #define OPTO_DU_ITERATOR_ASSERT 1
 160 #else
 161 #define OPTO_DU_ITERATOR_ASSERT 0
 162 #endif
 163 #endif //OPTO_DU_ITERATOR_ASSERT
 164 
 165 #if OPTO_DU_ITERATOR_ASSERT
 166 class DUIterator;
 167 class DUIterator_Fast;
 168 class DUIterator_Last;
 169 #else
 170 typedef uint   DUIterator;
 171 typedef Node** DUIterator_Fast;
 172 typedef Node** DUIterator_Last;
 173 #endif
 174 
 175 // Node Sentinel
 176 #define NodeSentinel (Node*)-1
 177 
 178 // Unknown count frequency
 179 #define COUNT_UNKNOWN (-1.0f)
 180 
 181 //------------------------------Node-------------------------------------------
 182 // Nodes define actions in the program.  They create values, which have types.
 183 // They are both vertices in a directed graph and program primitives.  Nodes
 184 // are labeled; the label is the "opcode", the primitive function in the lambda
 185 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 186 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 187 // the Node's function.  These inputs also define a Type equation for the Node.
 188 // Solving these Type equations amounts to doing dataflow analysis.
 189 // Control and data are uniformly represented in the graph.  Finally, Nodes
 190 // have a unique dense integer index which is used to index into side arrays
 191 // whenever I have phase-specific information.
 192 
 193 class Node {
 194   friend class VMStructs;
 195 
 196   // Lots of restrictions on cloning Nodes
 197   Node(const Node&);            // not defined; linker error to use these
 198   Node &operator=(const Node &rhs);
 199 
 200 public:
 201   friend class Compile;
 202   #if OPTO_DU_ITERATOR_ASSERT
 203   friend class DUIterator_Common;
 204   friend class DUIterator;
 205   friend class DUIterator_Fast;
 206   friend class DUIterator_Last;
 207   #endif
 208 
 209   // Because Nodes come and go, I define an Arena of Node structures to pull
 210   // from.  This should allow fast access to node creation & deletion.  This
 211   // field is a local cache of a value defined in some "program fragment" for
 212   // which these Nodes are just a part of.
 213 
 214   // New Operator that takes a Compile pointer, this will eventually
 215   // be the "new" New operator.
 216   inline void* operator new( size_t x, Compile* C) throw() {
 217     Node* n = (Node*)C->node_arena()->Amalloc_D(x);
 218 #ifdef ASSERT
 219     n->_in = (Node**)n; // magic cookie for assertion check
 220 #endif
 221     n->_out = (Node**)C;
 222     return (void*)n;
 223   }
 224 
 225   // Delete is a NOP
 226   void operator delete( void *ptr ) {}
 227   // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 228   void destruct();
 229 
 230   // Create a new Node.  Required is the number is of inputs required for
 231   // semantic correctness.
 232   Node( uint required );
 233 
 234   // Create a new Node with given input edges.
 235   // This version requires use of the "edge-count" new.
 236   // E.g.  new (C,3) FooNode( C, NULL, left, right );
 237   Node( Node *n0 );
 238   Node( Node *n0, Node *n1 );
 239   Node( Node *n0, Node *n1, Node *n2 );
 240   Node( Node *n0, Node *n1, Node *n2, Node *n3 );
 241   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
 242   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
 243   Node( Node *n0, Node *n1, Node *n2, Node *n3,
 244             Node *n4, Node *n5, Node *n6 );
 245 
 246   // Clone an inherited Node given only the base Node type.
 247   Node* clone() const;
 248 
 249   // Clone a Node, immediately supplying one or two new edges.
 250   // The first and second arguments, if non-null, replace in(1) and in(2),
 251   // respectively.
 252   Node* clone_with_data_edge(Node* in1, Node* in2 = NULL) const {
 253     Node* nn = clone();
 254     if (in1 != NULL)  nn->set_req(1, in1);
 255     if (in2 != NULL)  nn->set_req(2, in2);
 256     return nn;
 257   }
 258 
 259 private:
 260   // Shared setup for the above constructors.
 261   // Handles all interactions with Compile::current.
 262   // Puts initial values in all Node fields except _idx.
 263   // Returns the initial value for _idx, which cannot
 264   // be initialized by assignment.
 265   inline int Init(int req, Compile* C);
 266 
 267 //----------------- input edge handling
 268 protected:
 269   friend class PhaseCFG;        // Access to address of _in array elements
 270   Node **_in;                   // Array of use-def references to Nodes
 271   Node **_out;                  // Array of def-use references to Nodes
 272 
 273   // Input edges are split into two categories.  Required edges are required
 274   // for semantic correctness; order is important and NULLs are allowed.
 275   // Precedence edges are used to help determine execution order and are
 276   // added, e.g., for scheduling purposes.  They are unordered and not
 277   // duplicated; they have no embedded NULLs.  Edges from 0 to _cnt-1
 278   // are required, from _cnt to _max-1 are precedence edges.
 279   node_idx_t _cnt;              // Total number of required Node inputs.
 280 
 281   node_idx_t _max;              // Actual length of input array.
 282 
 283   // Output edges are an unordered list of def-use edges which exactly
 284   // correspond to required input edges which point from other nodes
 285   // to this one.  Thus the count of the output edges is the number of
 286   // users of this node.
 287   node_idx_t _outcnt;           // Total number of Node outputs.
 288 
 289   node_idx_t _outmax;           // Actual length of output array.
 290 
 291   // Grow the actual input array to the next larger power-of-2 bigger than len.
 292   void grow( uint len );
 293   // Grow the output array to the next larger power-of-2 bigger than len.
 294   void out_grow( uint len );
 295 
 296  public:
 297   // Each Node is assigned a unique small/dense number.  This number is used
 298   // to index into auxiliary arrays of data and bit vectors.
 299   // The field _idx is declared constant to defend against inadvertent assignments,
 300   // since it is used by clients as a naked field. However, the field's value can be
 301   // changed using the set_idx() method.
 302   //
 303   // The PhaseRenumberLive phase renumbers nodes based on liveness information.
 304   // Therefore, it updates the value of the _idx field. The parse-time _idx is
 305   // preserved in _parse_idx.
 306   const node_idx_t _idx;
 307   DEBUG_ONLY(const node_idx_t _parse_idx;)
 308 
 309   // Get the (read-only) number of input edges
 310   uint req() const { return _cnt; }
 311   uint len() const { return _max; }
 312   // Get the (read-only) number of output edges
 313   uint outcnt() const { return _outcnt; }
 314 
 315 #if OPTO_DU_ITERATOR_ASSERT
 316   // Iterate over the out-edges of this node.  Deletions are illegal.
 317   inline DUIterator outs() const;
 318   // Use this when the out array might have changed to suppress asserts.
 319   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 320   // Does the node have an out at this position?  (Used for iteration.)
 321   inline bool has_out(DUIterator& i) const;
 322   inline Node*    out(DUIterator& i) const;
 323   // Iterate over the out-edges of this node.  All changes are illegal.
 324   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 325   inline Node*    fast_out(DUIterator_Fast& i) const;
 326   // Iterate over the out-edges of this node, deleting one at a time.
 327   inline DUIterator_Last last_outs(DUIterator_Last& min) const;
 328   inline Node*    last_out(DUIterator_Last& i) const;
 329   // The inline bodies of all these methods are after the iterator definitions.
 330 #else
 331   // Iterate over the out-edges of this node.  Deletions are illegal.
 332   // This iteration uses integral indexes, to decouple from array reallocations.
 333   DUIterator outs() const  { return 0; }
 334   // Use this when the out array might have changed to suppress asserts.
 335   DUIterator refresh_out_pos(DUIterator i) const { return i; }
 336 
 337   // Reference to the i'th output Node.  Error if out of bounds.
 338   Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
 339   // Does the node have an out at this position?  (Used for iteration.)
 340   bool has_out(DUIterator i) const { return i < _outcnt; }
 341 
 342   // Iterate over the out-edges of this node.  All changes are illegal.
 343   // This iteration uses a pointer internal to the out array.
 344   DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
 345     Node** out = _out;
 346     // Assign a limit pointer to the reference argument:
 347     max = out + (ptrdiff_t)_outcnt;
 348     // Return the base pointer:
 349     return out;
 350   }
 351   Node*    fast_out(DUIterator_Fast i) const  { return *i; }
 352   // Iterate over the out-edges of this node, deleting one at a time.
 353   // This iteration uses a pointer internal to the out array.
 354   DUIterator_Last last_outs(DUIterator_Last& min) const {
 355     Node** out = _out;
 356     // Assign a limit pointer to the reference argument:
 357     min = out;
 358     // Return the pointer to the start of the iteration:
 359     return out + (ptrdiff_t)_outcnt - 1;
 360   }
 361   Node*    last_out(DUIterator_Last i) const  { return *i; }
 362 #endif
 363 
 364   // Reference to the i'th input Node.  Error if out of bounds.
 365   Node* in(uint i) const { assert(i < _max, err_msg_res("oob: i=%d, _max=%d", i, _max)); return _in[i]; }
 366   // Reference to the i'th input Node.  NULL if out of bounds.
 367   Node* lookup(uint i) const { return ((i < _max) ? _in[i] : NULL); }
 368   // Reference to the i'th output Node.  Error if out of bounds.
 369   // Use this accessor sparingly.  We are going trying to use iterators instead.
 370   Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
 371   // Return the unique out edge.
 372   Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
 373   // Delete out edge at position 'i' by moving last out edge to position 'i'
 374   void  raw_del_out(uint i) {
 375     assert(i < _outcnt,"oob");
 376     assert(_outcnt > 0,"oob");
 377     #if OPTO_DU_ITERATOR_ASSERT
 378     // Record that a change happened here.
 379     debug_only(_last_del = _out[i]; ++_del_tick);
 380     #endif
 381     _out[i] = _out[--_outcnt];
 382     // Smash the old edge so it can't be used accidentally.
 383     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 384   }
 385 
 386 #ifdef ASSERT
 387   bool is_dead() const;
 388 #define is_not_dead(n) ((n) == NULL || !VerifyIterativeGVN || !((n)->is_dead()))
 389 #endif
 390   // Check whether node has become unreachable
 391   bool is_unreachable(PhaseIterGVN &igvn) const;
 392 
 393   // Set a required input edge, also updates corresponding output edge
 394   void add_req( Node *n ); // Append a NEW required input
 395   void add_req( Node *n0, Node *n1 ) {
 396     add_req(n0); add_req(n1); }
 397   void add_req( Node *n0, Node *n1, Node *n2 ) {
 398     add_req(n0); add_req(n1); add_req(n2); }
 399   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 400   void del_req( uint idx ); // Delete required edge & compact
 401   void del_req_ordered( uint idx ); // Delete required edge & compact with preserved order
 402   void ins_req( uint i, Node *n ); // Insert a NEW required input
 403   void set_req( uint i, Node *n ) {
 404     assert( is_not_dead(n), "can not use dead node");
 405     assert( i < _cnt, err_msg_res("oob: i=%d, _cnt=%d", i, _cnt));
 406     assert( !VerifyHashTableKeys || _hash_lock == 0,
 407             "remove node from hash table before modifying it");
 408     Node** p = &_in[i];    // cache this._in, across the del_out call
 409     if (*p != NULL)  (*p)->del_out((Node *)this);
 410     (*p) = n;
 411     if (n != NULL)      n->add_out((Node *)this);
 412   }
 413   // Light version of set_req() to init inputs after node creation.
 414   void init_req( uint i, Node *n ) {
 415     assert( i == 0 && this == n ||
 416             is_not_dead(n), "can not use dead node");
 417     assert( i < _cnt, "oob");
 418     assert( !VerifyHashTableKeys || _hash_lock == 0,
 419             "remove node from hash table before modifying it");
 420     assert( _in[i] == NULL, "sanity");
 421     _in[i] = n;
 422     if (n != NULL)      n->add_out((Node *)this);
 423   }
 424   // Find first occurrence of n among my edges:
 425   int find_edge(Node* n);
 426   int replace_edge(Node* old, Node* neww);
 427   int replace_edges_in_range(Node* old, Node* neww, int start, int end);
 428   // NULL out all inputs to eliminate incoming Def-Use edges.
 429   // Return the number of edges between 'n' and 'this'
 430   int  disconnect_inputs(Node *n, Compile *c);
 431 
 432   // Quickly, return true if and only if I am Compile::current()->top().
 433   bool is_top() const {
 434     assert((this == (Node*) Compile::current()->top()) == (_out == NULL), "");
 435     return (_out == NULL);
 436   }
 437   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 438   void setup_is_top();
 439 
 440   // Strip away casting.  (It is depth-limited.)
 441   Node* uncast() const;
 442   // Return whether two Nodes are equivalent, after stripping casting.
 443   bool eqv_uncast(const Node* n) const {
 444     return (this->uncast() == n->uncast());
 445   }
 446 
 447 private:
 448   static Node* uncast_helper(const Node* n);
 449 
 450   // Add an output edge to the end of the list
 451   void add_out( Node *n ) {
 452     if (is_top())  return;
 453     if( _outcnt == _outmax ) out_grow(_outcnt);
 454     _out[_outcnt++] = n;
 455   }
 456   // Delete an output edge
 457   void del_out( Node *n ) {
 458     if (is_top())  return;
 459     Node** outp = &_out[_outcnt];
 460     // Find and remove n
 461     do {
 462       assert(outp > _out, "Missing Def-Use edge");
 463     } while (*--outp != n);
 464     *outp = _out[--_outcnt];
 465     // Smash the old edge so it can't be used accidentally.
 466     debug_only(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 467     // Record that a change happened here.
 468     #if OPTO_DU_ITERATOR_ASSERT
 469     debug_only(_last_del = n; ++_del_tick);
 470     #endif
 471   }
 472 
 473 public:
 474   // Globally replace this node by a given new node, updating all uses.
 475   void replace_by(Node* new_node);
 476   // Globally replace this node by a given new node, updating all uses
 477   // and cutting input edges of old node.
 478   void subsume_by(Node* new_node, Compile* c) {
 479     replace_by(new_node);
 480     disconnect_inputs(NULL, c);
 481   }
 482   void set_req_X( uint i, Node *n, PhaseIterGVN *igvn );
 483   // Find the one non-null required input.  RegionNode only
 484   Node *nonnull_req() const;
 485   // Add or remove precedence edges
 486   void add_prec( Node *n );
 487   void rm_prec( uint i );
 488   void set_prec( uint i, Node *n ) {
 489     assert( is_not_dead(n), "can not use dead node");
 490     assert( i >= _cnt, "not a precedence edge");
 491     if (_in[i] != NULL) _in[i]->del_out((Node *)this);
 492     _in[i] = n;
 493     if (n != NULL) n->add_out((Node *)this);
 494   }
 495   // Set this node's index, used by cisc_version to replace current node
 496   void set_idx(uint new_idx) {
 497     const node_idx_t* ref = &_idx;
 498     *(node_idx_t*)ref = new_idx;
 499   }
 500   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 501   void swap_edges(uint i1, uint i2) {
 502     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 503     // Def-Use info is unchanged
 504     Node* n1 = in(i1);
 505     Node* n2 = in(i2);
 506     _in[i1] = n2;
 507     _in[i2] = n1;
 508     // If this node is in the hash table, make sure it doesn't need a rehash.
 509     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 510   }
 511 
 512   // Iterators over input Nodes for a Node X are written as:
 513   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 514   // NOTE: Required edges can contain embedded NULL pointers.
 515 
 516 //----------------- Other Node Properties
 517 
 518   // Generate class id for some ideal nodes to avoid virtual query
 519   // methods is_<Node>().
 520   // Class id is the set of bits corresponded to the node class and all its
 521   // super classes so that queries for super classes are also valid.
 522   // Subclasses of the same super class have different assigned bit
 523   // (the third parameter in the macro DEFINE_CLASS_ID).
 524   // Classes with deeper hierarchy are declared first.
 525   // Classes with the same hierarchy depth are sorted by usage frequency.
 526   //
 527   // The query method masks the bits to cut off bits of subclasses
 528   // and then compare the result with the class id
 529   // (see the macro DEFINE_CLASS_QUERY below).
 530   //
 531   //  Class_MachCall=30, ClassMask_MachCall=31
 532   // 12               8               4               0
 533   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 534   //                                  |   |   |   |
 535   //                                  |   |   |   Bit_Mach=2
 536   //                                  |   |   Bit_MachReturn=4
 537   //                                  |   Bit_MachSafePoint=8
 538   //                                  Bit_MachCall=16
 539   //
 540   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 541   // 12               8               4               0
 542   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 543   //                              |   |   |
 544   //                              |   |   Bit_Region=8
 545   //                              |   Bit_Loop=16
 546   //                              Bit_CountedLoop=32
 547 
 548   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 549   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 550   Class_##cl = Class_##supcl + Bit_##cl , \
 551   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 552 
 553   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 554   // so that it's values fits into 16 bits.
 555   enum NodeClasses {
 556     Bit_Node   = 0x0000,
 557     Class_Node = 0x0000,
 558     ClassMask_Node = 0xFFFF,
 559 
 560     DEFINE_CLASS_ID(Multi, Node, 0)
 561       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 562         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 563           DEFINE_CLASS_ID(CallJava,         Call, 0)
 564             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 565             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 566           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 567             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 568           DEFINE_CLASS_ID(Allocate,         Call, 2)
 569             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 570           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 571             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 572             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 573       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 574         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 575           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 576           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 577         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 578           DEFINE_CLASS_ID(CountedLoopEnd, If, 0)
 579         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 580       DEFINE_CLASS_ID(Start,       Multi, 2)
 581       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 582         DEFINE_CLASS_ID(Initialize,       MemBar, 0)
 583         DEFINE_CLASS_ID(MemBarStoreStore, MemBar, 1)
 584 
 585     DEFINE_CLASS_ID(Mach,  Node, 1)
 586       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 587         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 588           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 589             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 590               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 591               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 592             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 593               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 594       DEFINE_CLASS_ID(MachBranch, Mach, 1)
 595         DEFINE_CLASS_ID(MachIf,         MachBranch, 0)
 596         DEFINE_CLASS_ID(MachGoto,       MachBranch, 1)
 597         DEFINE_CLASS_ID(MachNullCheck,  MachBranch, 2)
 598       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 2)
 599       DEFINE_CLASS_ID(MachTemp,         Mach, 3)
 600       DEFINE_CLASS_ID(MachConstantBase, Mach, 4)
 601       DEFINE_CLASS_ID(MachConstant,     Mach, 5)
 602       DEFINE_CLASS_ID(MachMerge,        Mach, 6)
 603 
 604     DEFINE_CLASS_ID(Type,  Node, 2)
 605       DEFINE_CLASS_ID(Phi,   Type, 0)
 606       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 607         DEFINE_CLASS_ID(CastII, ConstraintCast, 0)
 608       DEFINE_CLASS_ID(CheckCastPP, Type, 2)
 609       DEFINE_CLASS_ID(CMove, Type, 3)
 610       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 611       DEFINE_CLASS_ID(DecodeNarrowPtr, Type, 5)
 612         DEFINE_CLASS_ID(DecodeN, DecodeNarrowPtr, 0)
 613         DEFINE_CLASS_ID(DecodeNKlass, DecodeNarrowPtr, 1)
 614       DEFINE_CLASS_ID(EncodeNarrowPtr, Type, 6)
 615         DEFINE_CLASS_ID(EncodeP, EncodeNarrowPtr, 0)
 616         DEFINE_CLASS_ID(EncodePKlass, EncodeNarrowPtr, 1)
 617 
 618     DEFINE_CLASS_ID(Proj,  Node, 3)
 619       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 620       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 621       DEFINE_CLASS_ID(IfTrue,    Proj, 2)
 622       DEFINE_CLASS_ID(IfFalse,   Proj, 3)
 623       DEFINE_CLASS_ID(Parm,      Proj, 4)
 624       DEFINE_CLASS_ID(MachProj,  Proj, 5)
 625 
 626     DEFINE_CLASS_ID(Mem,   Node, 4)
 627       DEFINE_CLASS_ID(Load,  Mem, 0)
 628         DEFINE_CLASS_ID(LoadVector,  Load, 0)
 629       DEFINE_CLASS_ID(Store, Mem, 1)
 630         DEFINE_CLASS_ID(StoreVector, Store, 0)
 631       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 632 
 633     DEFINE_CLASS_ID(Region, Node, 5)
 634       DEFINE_CLASS_ID(Loop, Region, 0)
 635         DEFINE_CLASS_ID(Root,        Loop, 0)
 636         DEFINE_CLASS_ID(CountedLoop, Loop, 1)
 637 
 638     DEFINE_CLASS_ID(Sub,   Node, 6)
 639       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 640         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
 641         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
 642 
 643     DEFINE_CLASS_ID(MergeMem, Node, 7)
 644     DEFINE_CLASS_ID(Bool,     Node, 8)
 645     DEFINE_CLASS_ID(AddP,     Node, 9)
 646     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 647     DEFINE_CLASS_ID(Add,      Node, 11)
 648     DEFINE_CLASS_ID(Mul,      Node, 12)
 649     DEFINE_CLASS_ID(Vector,   Node, 13)
 650     DEFINE_CLASS_ID(ClearArray, Node, 14)
 651 
 652     _max_classes  = ClassMask_ClearArray
 653   };
 654   #undef DEFINE_CLASS_ID
 655 
 656   // Flags are sorted by usage frequency.
 657   enum NodeFlags {
 658     Flag_is_Copy                     = 0x01, // should be first bit to avoid shift
 659     Flag_rematerialize               = Flag_is_Copy << 1,
 660     Flag_needs_anti_dependence_check = Flag_rematerialize << 1,
 661     Flag_is_macro                    = Flag_needs_anti_dependence_check << 1,
 662     Flag_is_Con                      = Flag_is_macro << 1,
 663     Flag_is_cisc_alternate           = Flag_is_Con << 1,
 664     Flag_is_dead_loop_safe           = Flag_is_cisc_alternate << 1,
 665     Flag_may_be_short_branch         = Flag_is_dead_loop_safe << 1,
 666     Flag_avoid_back_to_back_before   = Flag_may_be_short_branch << 1,
 667     Flag_avoid_back_to_back_after    = Flag_avoid_back_to_back_before << 1,
 668     Flag_has_call                    = Flag_avoid_back_to_back_after << 1,
 669     Flag_is_expensive                = Flag_has_call << 1,
 670     _max_flags = (Flag_is_expensive << 1) - 1 // allow flags combination
 671   };
 672 
 673 private:
 674   jushort _class_id;
 675   jushort _flags;
 676 
 677 protected:
 678   // These methods should be called from constructors only.
 679   void init_class_id(jushort c) {
 680     assert(c <= _max_classes, "invalid node class");
 681     _class_id = c; // cast out const
 682   }
 683   void init_flags(jushort fl) {
 684     assert(fl <= _max_flags, "invalid node flag");
 685     _flags |= fl;
 686   }
 687   void clear_flag(jushort fl) {
 688     assert(fl <= _max_flags, "invalid node flag");
 689     _flags &= ~fl;
 690   }
 691 
 692 public:
 693   const jushort class_id() const { return _class_id; }
 694 
 695   const jushort flags() const { return _flags; }
 696 
 697   // Return a dense integer opcode number
 698   virtual int Opcode() const;
 699 
 700   // Virtual inherited Node size
 701   virtual uint size_of() const;
 702 
 703   // Other interesting Node properties
 704   #define DEFINE_CLASS_QUERY(type)                           \
 705   bool is_##type() const {                                   \
 706     return ((_class_id & ClassMask_##type) == Class_##type); \
 707   }                                                          \
 708   type##Node *as_##type() const {                            \
 709     assert(is_##type(), "invalid node class");               \
 710     return (type##Node*)this;                                \
 711   }                                                          \
 712   type##Node* isa_##type() const {                           \
 713     return (is_##type()) ? as_##type() : NULL;               \
 714   }
 715 
 716   DEFINE_CLASS_QUERY(AbstractLock)
 717   DEFINE_CLASS_QUERY(Add)
 718   DEFINE_CLASS_QUERY(AddP)
 719   DEFINE_CLASS_QUERY(Allocate)
 720   DEFINE_CLASS_QUERY(AllocateArray)
 721   DEFINE_CLASS_QUERY(Bool)
 722   DEFINE_CLASS_QUERY(BoxLock)
 723   DEFINE_CLASS_QUERY(Call)
 724   DEFINE_CLASS_QUERY(CallDynamicJava)
 725   DEFINE_CLASS_QUERY(CallJava)
 726   DEFINE_CLASS_QUERY(CallLeaf)
 727   DEFINE_CLASS_QUERY(CallRuntime)
 728   DEFINE_CLASS_QUERY(CallStaticJava)
 729   DEFINE_CLASS_QUERY(Catch)
 730   DEFINE_CLASS_QUERY(CatchProj)
 731   DEFINE_CLASS_QUERY(CheckCastPP)
 732   DEFINE_CLASS_QUERY(CastII)
 733   DEFINE_CLASS_QUERY(ConstraintCast)
 734   DEFINE_CLASS_QUERY(ClearArray)
 735   DEFINE_CLASS_QUERY(CMove)
 736   DEFINE_CLASS_QUERY(Cmp)
 737   DEFINE_CLASS_QUERY(CountedLoop)
 738   DEFINE_CLASS_QUERY(CountedLoopEnd)
 739   DEFINE_CLASS_QUERY(DecodeNarrowPtr)
 740   DEFINE_CLASS_QUERY(DecodeN)
 741   DEFINE_CLASS_QUERY(DecodeNKlass)
 742   DEFINE_CLASS_QUERY(EncodeNarrowPtr)
 743   DEFINE_CLASS_QUERY(EncodeP)
 744   DEFINE_CLASS_QUERY(EncodePKlass)
 745   DEFINE_CLASS_QUERY(FastLock)
 746   DEFINE_CLASS_QUERY(FastUnlock)
 747   DEFINE_CLASS_QUERY(If)
 748   DEFINE_CLASS_QUERY(IfFalse)
 749   DEFINE_CLASS_QUERY(IfTrue)
 750   DEFINE_CLASS_QUERY(Initialize)
 751   DEFINE_CLASS_QUERY(Jump)
 752   DEFINE_CLASS_QUERY(JumpProj)
 753   DEFINE_CLASS_QUERY(Load)
 754   DEFINE_CLASS_QUERY(LoadStore)
 755   DEFINE_CLASS_QUERY(Lock)
 756   DEFINE_CLASS_QUERY(Loop)
 757   DEFINE_CLASS_QUERY(Mach)
 758   DEFINE_CLASS_QUERY(MachBranch)
 759   DEFINE_CLASS_QUERY(MachCall)
 760   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 761   DEFINE_CLASS_QUERY(MachCallJava)
 762   DEFINE_CLASS_QUERY(MachCallLeaf)
 763   DEFINE_CLASS_QUERY(MachCallRuntime)
 764   DEFINE_CLASS_QUERY(MachCallStaticJava)
 765   DEFINE_CLASS_QUERY(MachConstantBase)
 766   DEFINE_CLASS_QUERY(MachConstant)
 767   DEFINE_CLASS_QUERY(MachGoto)
 768   DEFINE_CLASS_QUERY(MachIf)
 769   DEFINE_CLASS_QUERY(MachNullCheck)
 770   DEFINE_CLASS_QUERY(MachProj)
 771   DEFINE_CLASS_QUERY(MachReturn)
 772   DEFINE_CLASS_QUERY(MachSafePoint)
 773   DEFINE_CLASS_QUERY(MachSpillCopy)
 774   DEFINE_CLASS_QUERY(MachTemp)
 775   DEFINE_CLASS_QUERY(MachMerge)
 776   DEFINE_CLASS_QUERY(Mem)
 777   DEFINE_CLASS_QUERY(MemBar)
 778   DEFINE_CLASS_QUERY(MemBarStoreStore)
 779   DEFINE_CLASS_QUERY(MergeMem)
 780   DEFINE_CLASS_QUERY(Mul)
 781   DEFINE_CLASS_QUERY(Multi)
 782   DEFINE_CLASS_QUERY(MultiBranch)
 783   DEFINE_CLASS_QUERY(Parm)
 784   DEFINE_CLASS_QUERY(PCTable)
 785   DEFINE_CLASS_QUERY(Phi)
 786   DEFINE_CLASS_QUERY(Proj)
 787   DEFINE_CLASS_QUERY(Region)
 788   DEFINE_CLASS_QUERY(Root)
 789   DEFINE_CLASS_QUERY(SafePoint)
 790   DEFINE_CLASS_QUERY(SafePointScalarObject)
 791   DEFINE_CLASS_QUERY(Start)
 792   DEFINE_CLASS_QUERY(Store)
 793   DEFINE_CLASS_QUERY(Sub)
 794   DEFINE_CLASS_QUERY(Type)
 795   DEFINE_CLASS_QUERY(Vector)
 796   DEFINE_CLASS_QUERY(LoadVector)
 797   DEFINE_CLASS_QUERY(StoreVector)
 798   DEFINE_CLASS_QUERY(Unlock)
 799 
 800   #undef DEFINE_CLASS_QUERY
 801 
 802   // duplicate of is_MachSpillCopy()
 803   bool is_SpillCopy () const {
 804     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
 805   }
 806 
 807   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
 808   // The data node which is safe to leave in dead loop during IGVN optimization.
 809   bool is_dead_loop_safe() const {
 810     return is_Phi() || (is_Proj() && in(0) == NULL) ||
 811            ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0 &&
 812             (!is_Proj() || !in(0)->is_Allocate()));
 813   }
 814 
 815   // is_Copy() returns copied edge index (0 or 1)
 816   uint is_Copy() const { return (_flags & Flag_is_Copy); }
 817 
 818   virtual bool is_CFG() const { return false; }
 819 
 820   // If this node is control-dependent on a test, can it be
 821   // rerouted to a dominating equivalent test?  This is usually
 822   // true of non-CFG nodes, but can be false for operations which
 823   // depend for their correct sequencing on more than one test.
 824   // (In that case, hoisting to a dominating test may silently
 825   // skip some other important test.)
 826   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
 827 
 828   // When building basic blocks, I need to have a notion of block beginning
 829   // Nodes, next block selector Nodes (block enders), and next block
 830   // projections.  These calls need to work on their machine equivalents.  The
 831   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
 832   bool is_block_start() const {
 833     if ( is_Region() )
 834       return this == (const Node*)in(0);
 835     else
 836       return is_Start();
 837   }
 838 
 839   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
 840   // Goto and Return.  This call also returns the block ending Node.
 841   virtual const Node *is_block_proj() const;
 842 
 843   // The node is a "macro" node which needs to be expanded before matching
 844   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
 845   // The node is expensive: the best control is set during loop opts
 846   bool is_expensive() const { return (_flags & Flag_is_expensive) != 0 && in(0) != NULL; }
 847 
 848 //----------------- Optimization
 849 
 850   // Get the worst-case Type output for this Node.
 851   virtual const class Type *bottom_type() const;
 852 
 853   // If we find a better type for a node, try to record it permanently.
 854   // Return true if this node actually changed.
 855   // Be sure to do the hash_delete game in the "rehash" variant.
 856   void raise_bottom_type(const Type* new_type);
 857 
 858   // Get the address type with which this node uses and/or defs memory,
 859   // or NULL if none.  The address type is conservatively wide.
 860   // Returns non-null for calls, membars, loads, stores, etc.
 861   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
 862   virtual const class TypePtr *adr_type() const { return NULL; }
 863 
 864   // Return an existing node which computes the same function as this node.
 865   // The optimistic combined algorithm requires this to return a Node which
 866   // is a small number of steps away (e.g., one of my inputs).
 867   virtual Node *Identity( PhaseTransform *phase );
 868 
 869   // Return the set of values this Node can take on at runtime.
 870   virtual const Type *Value( PhaseTransform *phase ) const;
 871 
 872   // Return a node which is more "ideal" than the current node.
 873   // The invariants on this call are subtle.  If in doubt, read the
 874   // treatise in node.cpp above the default implemention AND TEST WITH
 875   // +VerifyIterativeGVN!
 876   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 877 
 878   // Some nodes have specific Ideal subgraph transformations only if they are
 879   // unique users of specific nodes. Such nodes should be put on IGVN worklist
 880   // for the transformations to happen.
 881   bool has_special_unique_user() const;
 882 
 883   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
 884   Node* find_exact_control(Node* ctrl);
 885 
 886   // Check if 'this' node dominates or equal to 'sub'.
 887   bool dominates(Node* sub, Node_List &nlist);
 888 
 889 protected:
 890   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
 891 public:
 892 
 893   // Idealize graph, using DU info.  Done after constant propagation
 894   virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
 895 
 896   // See if there is valid pipeline info
 897   static  const Pipeline *pipeline_class();
 898   virtual const Pipeline *pipeline() const;
 899 
 900   // Compute the latency from the def to this instruction of the ith input node
 901   uint latency(uint i);
 902 
 903   // Hash & compare functions, for pessimistic value numbering
 904 
 905   // If the hash function returns the special sentinel value NO_HASH,
 906   // the node is guaranteed never to compare equal to any other node.
 907   // If we accidentally generate a hash with value NO_HASH the node
 908   // won't go into the table and we'll lose a little optimization.
 909   enum { NO_HASH = 0 };
 910   virtual uint hash() const;
 911   virtual uint cmp( const Node &n ) const;
 912 
 913   // Operation appears to be iteratively computed (such as an induction variable)
 914   // It is possible for this operation to return false for a loop-varying
 915   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
 916   bool is_iteratively_computed();
 917 
 918   // Determine if a node is Counted loop induction variable.
 919   // The method is defined in loopnode.cpp.
 920   const Node* is_loop_iv() const;
 921 
 922   // Return a node with opcode "opc" and same inputs as "this" if one can
 923   // be found; Otherwise return NULL;
 924   Node* find_similar(int opc);
 925 
 926   // Return the unique control out if only one. Null if none or more than one.
 927   Node* unique_ctrl_out();
 928 
 929 //----------------- Code Generation
 930 
 931   // Ideal register class for Matching.  Zero means unmatched instruction
 932   // (these are cloned instead of converted to machine nodes).
 933   virtual uint ideal_reg() const;
 934 
 935   static const uint NotAMachineReg;   // must be > max. machine register
 936 
 937   // Do we Match on this edge index or not?  Generally false for Control
 938   // and true for everything else.  Weird for calls & returns.
 939   virtual uint match_edge(uint idx) const;
 940 
 941   // Register class output is returned in
 942   virtual const RegMask &out_RegMask() const;
 943   // Register class input is expected in
 944   virtual const RegMask &in_RegMask(uint) const;
 945   // Should we clone rather than spill this instruction?
 946   bool rematerialize() const;
 947 
 948   // Return JVM State Object if this Node carries debug info, or NULL otherwise
 949   virtual JVMState* jvms() const;
 950 
 951   // Print as assembly
 952   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
 953   // Emit bytes starting at parameter 'ptr'
 954   // Bump 'ptr' by the number of output bytes
 955   virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const;
 956   // Size of instruction in bytes
 957   virtual uint size(PhaseRegAlloc *ra_) const;
 958 
 959   // Convenience function to extract an integer constant from a node.
 960   // If it is not an integer constant (either Con, CastII, or Mach),
 961   // return value_if_unknown.
 962   jint find_int_con(jint value_if_unknown) const {
 963     const TypeInt* t = find_int_type();
 964     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
 965   }
 966   // Return the constant, knowing it is an integer constant already
 967   jint get_int() const {
 968     const TypeInt* t = find_int_type();
 969     guarantee(t != NULL, "must be con");
 970     return t->get_con();
 971   }
 972   // Here's where the work is done.  Can produce non-constant int types too.
 973   const TypeInt* find_int_type() const;
 974 
 975   // Same thing for long (and intptr_t, via type.hpp):
 976   jlong get_long() const {
 977     const TypeLong* t = find_long_type();
 978     guarantee(t != NULL, "must be con");
 979     return t->get_con();
 980   }
 981   jlong find_long_con(jint value_if_unknown) const {
 982     const TypeLong* t = find_long_type();
 983     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
 984   }
 985   const TypeLong* find_long_type() const;
 986 
 987   const TypePtr* get_ptr_type() const;
 988 
 989   // These guys are called by code generated by ADLC:
 990   intptr_t get_ptr() const;
 991   intptr_t get_narrowcon() const;
 992   jdouble getd() const;
 993   jfloat getf() const;
 994 
 995   // Nodes which are pinned into basic blocks
 996   virtual bool pinned() const { return false; }
 997 
 998   // Nodes which use memory without consuming it, hence need antidependences
 999   // More specifically, needs_anti_dependence_check returns true iff the node
1000   // (a) does a load, and (b) does not perform a store (except perhaps to a
1001   // stack slot or some other unaliased location).
1002   bool needs_anti_dependence_check() const;
1003 
1004   // Return which operand this instruction may cisc-spill. In other words,
1005   // return operand position that can convert from reg to memory access
1006   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
1007   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
1008 
1009 //----------------- Graph walking
1010 public:
1011   // Walk and apply member functions recursively.
1012   // Supplied (this) pointer is root.
1013   void walk(NFunc pre, NFunc post, void *env);
1014   static void nop(Node &, void*); // Dummy empty function
1015   static void packregion( Node &n, void* );
1016 private:
1017   void walk_(NFunc pre, NFunc post, void *env, VectorSet &visited);
1018 
1019 //----------------- Printing, etc
1020 public:
1021 #ifndef PRODUCT
1022   Node* find(int idx) const;         // Search the graph for the given idx.
1023   Node* find_ctrl(int idx) const;    // Search control ancestors for the given idx.
1024   void dump() const { dump("\n"); }  // Print this node.
1025   void dump(const char* suffix, outputStream *st = tty) const;// Print this node.
1026   void dump(int depth) const;        // Print this node, recursively to depth d
1027   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
1028   virtual void dump_req(outputStream *st = tty) const;     // Print required-edge info
1029   virtual void dump_prec(outputStream *st = tty) const;    // Print precedence-edge info
1030   virtual void dump_out(outputStream *st = tty) const;     // Print the output edge info
1031   virtual void dump_spec(outputStream *st) const {}; // Print per-node info
1032   void verify_edges(Unique_Node_List &visited); // Verify bi-directional edges
1033   void verify() const;               // Check Def-Use info for my subgraph
1034   static void verify_recur(const Node *n, int verify_depth, VectorSet &old_space, VectorSet &new_space);
1035 
1036   // This call defines a class-unique string used to identify class instances
1037   virtual const char *Name() const;
1038 
1039   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1040   // RegMask Print Functions
1041   void dump_in_regmask(int idx) { in_RegMask(idx).dump(); }
1042   void dump_out_regmask() { out_RegMask().dump(); }
1043   static bool in_dump() { return Compile::current()->_in_dump_cnt > 0; }
1044   void fast_dump() const {
1045     tty->print("%4d: %-17s", _idx, Name());
1046     for (uint i = 0; i < len(); i++)
1047       if (in(i))
1048         tty->print(" %4d", in(i)->_idx);
1049       else
1050         tty->print(" NULL");
1051     tty->print("\n");
1052   }
1053 #endif
1054 #ifdef ASSERT
1055   void verify_construction();
1056   bool verify_jvms(const JVMState* jvms) const;
1057   int  _debug_idx;                     // Unique value assigned to every node.
1058   int   debug_idx() const              { return _debug_idx; }
1059   void  set_debug_idx( int debug_idx ) { _debug_idx = debug_idx; }
1060 
1061   Node* _debug_orig;                   // Original version of this, if any.
1062   Node*  debug_orig() const            { return _debug_orig; }
1063   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1064 
1065   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1066   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1067   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1068 
1069   static void init_NodeProperty();
1070 
1071   #if OPTO_DU_ITERATOR_ASSERT
1072   const Node* _last_del;               // The last deleted node.
1073   uint        _del_tick;               // Bumped when a deletion happens..
1074   #endif
1075 #endif
1076 };
1077 
1078 //-----------------------------------------------------------------------------
1079 // Iterators over DU info, and associated Node functions.
1080 
1081 #if OPTO_DU_ITERATOR_ASSERT
1082 
1083 // Common code for assertion checking on DU iterators.
1084 class DUIterator_Common VALUE_OBJ_CLASS_SPEC {
1085 #ifdef ASSERT
1086  protected:
1087   bool         _vdui;               // cached value of VerifyDUIterators
1088   const Node*  _node;               // the node containing the _out array
1089   uint         _outcnt;             // cached node->_outcnt
1090   uint         _del_tick;           // cached node->_del_tick
1091   Node*        _last;               // last value produced by the iterator
1092 
1093   void sample(const Node* node);    // used by c'tor to set up for verifies
1094   void verify(const Node* node, bool at_end_ok = false);
1095   void verify_resync();
1096   void reset(const DUIterator_Common& that);
1097 
1098 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1099   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1100 #else
1101   #define I_VDUI_ONLY(i,x) { }
1102 #endif //ASSERT
1103 };
1104 
1105 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1106 
1107 // Default DU iterator.  Allows appends onto the out array.
1108 // Allows deletion from the out array only at the current point.
1109 // Usage:
1110 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1111 //    Node* y = x->out(i);
1112 //    ...
1113 //  }
1114 // Compiles in product mode to a unsigned integer index, which indexes
1115 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1116 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1117 // before continuing the loop.  You must delete only the last-produced
1118 // edge.  You must delete only a single copy of the last-produced edge,
1119 // or else you must delete all copies at once (the first time the edge
1120 // is produced by the iterator).
1121 class DUIterator : public DUIterator_Common {
1122   friend class Node;
1123 
1124   // This is the index which provides the product-mode behavior.
1125   // Whatever the product-mode version of the system does to the
1126   // DUI index is done to this index.  All other fields in
1127   // this class are used only for assertion checking.
1128   uint         _idx;
1129 
1130   #ifdef ASSERT
1131   uint         _refresh_tick;    // Records the refresh activity.
1132 
1133   void sample(const Node* node); // Initialize _refresh_tick etc.
1134   void verify(const Node* node, bool at_end_ok = false);
1135   void verify_increment();       // Verify an increment operation.
1136   void verify_resync();          // Verify that we can back up over a deletion.
1137   void verify_finish();          // Verify that the loop terminated properly.
1138   void refresh();                // Resample verification info.
1139   void reset(const DUIterator& that);  // Resample after assignment.
1140   #endif
1141 
1142   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1143     { _idx = 0;                         debug_only(sample(node)); }
1144 
1145  public:
1146   // initialize to garbage; clear _vdui to disable asserts
1147   DUIterator()
1148     { /*initialize to garbage*/         debug_only(_vdui = false); }
1149 
1150   void operator++(int dummy_to_specify_postfix_op)
1151     { _idx++;                           VDUI_ONLY(verify_increment()); }
1152 
1153   void operator--()
1154     { VDUI_ONLY(verify_resync());       --_idx; }
1155 
1156   ~DUIterator()
1157     { VDUI_ONLY(verify_finish()); }
1158 
1159   void operator=(const DUIterator& that)
1160     { _idx = that._idx;                 debug_only(reset(that)); }
1161 };
1162 
1163 DUIterator Node::outs() const
1164   { return DUIterator(this, 0); }
1165 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1166   { I_VDUI_ONLY(i, i.refresh());        return i; }
1167 bool Node::has_out(DUIterator& i) const
1168   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1169 Node*    Node::out(DUIterator& i) const
1170   { I_VDUI_ONLY(i, i.verify(this));     return debug_only(i._last=) _out[i._idx]; }
1171 
1172 
1173 // Faster DU iterator.  Disallows insertions into the out array.
1174 // Allows deletion from the out array only at the current point.
1175 // Usage:
1176 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1177 //    Node* y = x->fast_out(i);
1178 //    ...
1179 //  }
1180 // Compiles in product mode to raw Node** pointer arithmetic, with
1181 // no reloading of pointers from the original node x.  If you delete,
1182 // you must perform "--i; --imax" just before continuing the loop.
1183 // If you delete multiple copies of the same edge, you must decrement
1184 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1185 class DUIterator_Fast : public DUIterator_Common {
1186   friend class Node;
1187   friend class DUIterator_Last;
1188 
1189   // This is the pointer which provides the product-mode behavior.
1190   // Whatever the product-mode version of the system does to the
1191   // DUI pointer is done to this pointer.  All other fields in
1192   // this class are used only for assertion checking.
1193   Node**       _outp;
1194 
1195   #ifdef ASSERT
1196   void verify(const Node* node, bool at_end_ok = false);
1197   void verify_limit();
1198   void verify_resync();
1199   void verify_relimit(uint n);
1200   void reset(const DUIterator_Fast& that);
1201   #endif
1202 
1203   // Note:  offset must be signed, since -1 is sometimes passed
1204   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1205     { _outp = node->_out + offset;      debug_only(sample(node)); }
1206 
1207  public:
1208   // initialize to garbage; clear _vdui to disable asserts
1209   DUIterator_Fast()
1210     { /*initialize to garbage*/         debug_only(_vdui = false); }
1211 
1212   void operator++(int dummy_to_specify_postfix_op)
1213     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1214 
1215   void operator--()
1216     { VDUI_ONLY(verify_resync());       --_outp; }
1217 
1218   void operator-=(uint n)   // applied to the limit only
1219     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1220 
1221   bool operator<(DUIterator_Fast& limit) {
1222     I_VDUI_ONLY(*this, this->verify(_node, true));
1223     I_VDUI_ONLY(limit, limit.verify_limit());
1224     return _outp < limit._outp;
1225   }
1226 
1227   void operator=(const DUIterator_Fast& that)
1228     { _outp = that._outp;               debug_only(reset(that)); }
1229 };
1230 
1231 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1232   // Assign a limit pointer to the reference argument:
1233   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1234   // Return the base pointer:
1235   return DUIterator_Fast(this, 0);
1236 }
1237 Node* Node::fast_out(DUIterator_Fast& i) const {
1238   I_VDUI_ONLY(i, i.verify(this));
1239   return debug_only(i._last=) *i._outp;
1240 }
1241 
1242 
1243 // Faster DU iterator.  Requires each successive edge to be removed.
1244 // Does not allow insertion of any edges.
1245 // Usage:
1246 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1247 //    Node* y = x->last_out(i);
1248 //    ...
1249 //  }
1250 // Compiles in product mode to raw Node** pointer arithmetic, with
1251 // no reloading of pointers from the original node x.
1252 class DUIterator_Last : private DUIterator_Fast {
1253   friend class Node;
1254 
1255   #ifdef ASSERT
1256   void verify(const Node* node, bool at_end_ok = false);
1257   void verify_limit();
1258   void verify_step(uint num_edges);
1259   #endif
1260 
1261   // Note:  offset must be signed, since -1 is sometimes passed
1262   DUIterator_Last(const Node* node, ptrdiff_t offset)
1263     : DUIterator_Fast(node, offset) { }
1264 
1265   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1266   void operator<(int)                              {} // do not use
1267 
1268  public:
1269   DUIterator_Last() { }
1270   // initialize to garbage
1271 
1272   void operator--()
1273     { _outp--;              VDUI_ONLY(verify_step(1));  }
1274 
1275   void operator-=(uint n)
1276     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1277 
1278   bool operator>=(DUIterator_Last& limit) {
1279     I_VDUI_ONLY(*this, this->verify(_node, true));
1280     I_VDUI_ONLY(limit, limit.verify_limit());
1281     return _outp >= limit._outp;
1282   }
1283 
1284   void operator=(const DUIterator_Last& that)
1285     { DUIterator_Fast::operator=(that); }
1286 };
1287 
1288 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1289   // Assign a limit pointer to the reference argument:
1290   imin = DUIterator_Last(this, 0);
1291   // Return the initial pointer:
1292   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1293 }
1294 Node* Node::last_out(DUIterator_Last& i) const {
1295   I_VDUI_ONLY(i, i.verify(this));
1296   return debug_only(i._last=) *i._outp;
1297 }
1298 
1299 #endif //OPTO_DU_ITERATOR_ASSERT
1300 
1301 #undef I_VDUI_ONLY
1302 #undef VDUI_ONLY
1303 
1304 // An Iterator that truly follows the iterator pattern.  Doesn't
1305 // support deletion but could be made to.
1306 //
1307 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1308 //     Node* m = i.get();
1309 //
1310 class SimpleDUIterator : public StackObj {
1311  private:
1312   Node* node;
1313   DUIterator_Fast i;
1314   DUIterator_Fast imax;
1315  public:
1316   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1317   bool has_next() { return i < imax; }
1318   void next() { i++; }
1319   Node* get() { return node->fast_out(i); }
1320 };
1321 
1322 
1323 //-----------------------------------------------------------------------------
1324 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1325 // Abstractly provides an infinite array of Node*'s, initialized to NULL.
1326 // Note that the constructor just zeros things, and since I use Arena
1327 // allocation I do not need a destructor to reclaim storage.
1328 class Node_Array : public ResourceObj {
1329   friend class VMStructs;
1330 protected:
1331   Arena *_a;                    // Arena to allocate in
1332   uint   _max;
1333   Node **_nodes;
1334   void   grow( uint i );        // Grow array node to fit
1335 public:
1336   Node_Array(Arena *a) : _a(a), _max(OptoNodeListSize) {
1337     _nodes = NEW_ARENA_ARRAY( a, Node *, OptoNodeListSize );
1338     for( int i = 0; i < OptoNodeListSize; i++ ) {
1339       _nodes[i] = NULL;
1340     }
1341   }
1342 
1343   Node_Array(Node_Array *na) : _a(na->_a), _max(na->_max), _nodes(na->_nodes) {}
1344   Node *operator[] ( uint i ) const // Lookup, or NULL for not mapped
1345   { return (i<_max) ? _nodes[i] : (Node*)NULL; }
1346   Node *at( uint i ) const { assert(i<_max,"oob"); return _nodes[i]; }
1347   Node **adr() { return _nodes; }
1348   // Extend the mapping: index i maps to Node *n.
1349   void map( uint i, Node *n ) { if( i>=_max ) grow(i); _nodes[i] = n; }
1350   void insert( uint i, Node *n );
1351   void remove( uint i );        // Remove, preserving order
1352   void sort( C_sort_func_t func);
1353   void reset( Arena *new_a );   // Zap mapping to empty; reclaim storage
1354   void clear();                 // Set all entries to NULL, keep storage
1355   uint Size() const { return _max; }
1356   void dump() const;
1357 };
1358 
1359 class Node_List : public Node_Array {
1360   friend class VMStructs;
1361   uint _cnt;
1362 public:
1363   Node_List() : Node_Array(Thread::current()->resource_area()), _cnt(0) {}
1364   Node_List(Arena *a) : Node_Array(a), _cnt(0) {}
1365   bool contains(const Node* n) const {
1366     for (uint e = 0; e < size(); e++) {
1367       if (at(e) == n) return true;
1368     }
1369     return false;
1370   }
1371   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1372   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1373   void push( Node *b ) { map(_cnt++,b); }
1374   void yank( Node *n );         // Find and remove
1375   Node *pop() { return _nodes[--_cnt]; }
1376   Node *rpop() { Node *b = _nodes[0]; _nodes[0]=_nodes[--_cnt]; return b;}
1377   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1378   uint size() const { return _cnt; }
1379   void dump() const;
1380   void dump_simple() const;
1381 };
1382 
1383 //------------------------------Unique_Node_List-------------------------------
1384 class Unique_Node_List : public Node_List {
1385   friend class VMStructs;
1386   VectorSet _in_worklist;
1387   uint _clock_index;            // Index in list where to pop from next
1388 public:
1389   Unique_Node_List() : Node_List(), _in_worklist(Thread::current()->resource_area()), _clock_index(0) {}
1390   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1391 
1392   void remove( Node *n );
1393   bool member( Node *n ) { return _in_worklist.test(n->_idx) != 0; }
1394   VectorSet &member_set(){ return _in_worklist; }
1395 
1396   void push( Node *b ) {
1397     if( !_in_worklist.test_set(b->_idx) )
1398       Node_List::push(b);
1399   }
1400   Node *pop() {
1401     if( _clock_index >= size() ) _clock_index = 0;
1402     Node *b = at(_clock_index);
1403     map( _clock_index, Node_List::pop());
1404     if (size() != 0) _clock_index++; // Always start from 0
1405     _in_worklist >>= b->_idx;
1406     return b;
1407   }
1408   Node *remove( uint i ) {
1409     Node *b = Node_List::at(i);
1410     _in_worklist >>= b->_idx;
1411     map(i,Node_List::pop());
1412     return b;
1413   }
1414   void yank( Node *n ) { _in_worklist >>= n->_idx; Node_List::yank(n); }
1415   void  clear() {
1416     _in_worklist.Clear();        // Discards storage but grows automatically
1417     Node_List::clear();
1418     _clock_index = 0;
1419   }
1420 
1421   // Used after parsing to remove useless nodes before Iterative GVN
1422   void remove_useless_nodes(VectorSet &useful);
1423 
1424 #ifndef PRODUCT
1425   void print_set() const { _in_worklist.print(); }
1426 #endif
1427 };
1428 
1429 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1430 inline void Compile::record_for_igvn(Node* n) {
1431   _for_igvn->push(n);
1432 }
1433 
1434 //------------------------------Node_Stack-------------------------------------
1435 class Node_Stack {
1436   friend class VMStructs;
1437 protected:
1438   struct INode {
1439     Node *node; // Processed node
1440     uint  indx; // Index of next node's child
1441   };
1442   INode *_inode_top; // tos, stack grows up
1443   INode *_inode_max; // End of _inodes == _inodes + _max
1444   INode *_inodes;    // Array storage for the stack
1445   Arena *_a;         // Arena to allocate in
1446   void grow();
1447 public:
1448   Node_Stack(int size) {
1449     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1450     _a = Thread::current()->resource_area();
1451     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1452     _inode_max = _inodes + max;
1453     _inode_top = _inodes - 1; // stack is empty
1454   }
1455 
1456   Node_Stack(Arena *a, int size) : _a(a) {
1457     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1458     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1459     _inode_max = _inodes + max;
1460     _inode_top = _inodes - 1; // stack is empty
1461   }
1462 
1463   void pop() {
1464     assert(_inode_top >= _inodes, "node stack underflow");
1465     --_inode_top;
1466   }
1467   void push(Node *n, uint i) {
1468     ++_inode_top;
1469     if (_inode_top >= _inode_max) grow();
1470     INode *top = _inode_top; // optimization
1471     top->node = n;
1472     top->indx = i;
1473   }
1474   Node *node() const {
1475     return _inode_top->node;
1476   }
1477   Node* node_at(uint i) const {
1478     assert(_inodes + i <= _inode_top, "in range");
1479     return _inodes[i].node;
1480   }
1481   uint index() const {
1482     return _inode_top->indx;
1483   }
1484   uint index_at(uint i) const {
1485     assert(_inodes + i <= _inode_top, "in range");
1486     return _inodes[i].indx;
1487   }
1488   void set_node(Node *n) {
1489     _inode_top->node = n;
1490   }
1491   void set_index(uint i) {
1492     _inode_top->indx = i;
1493   }
1494   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1495   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1496   bool is_nonempty() const { return (_inode_top >= _inodes); }
1497   bool is_empty() const { return (_inode_top < _inodes); }
1498   void clear() { _inode_top = _inodes - 1; } // retain storage
1499 
1500   // Node_Stack is used to map nodes.
1501   Node* find(uint idx) const;
1502 };
1503 
1504 
1505 //-----------------------------Node_Notes--------------------------------------
1506 // Debugging or profiling annotations loosely and sparsely associated
1507 // with some nodes.  See Compile::node_notes_at for the accessor.
1508 class Node_Notes VALUE_OBJ_CLASS_SPEC {
1509   friend class VMStructs;
1510   JVMState* _jvms;
1511 
1512 public:
1513   Node_Notes(JVMState* jvms = NULL) {
1514     _jvms = jvms;
1515   }
1516 
1517   JVMState* jvms()            { return _jvms; }
1518   void  set_jvms(JVMState* x) {        _jvms = x; }
1519 
1520   // True if there is nothing here.
1521   bool is_clear() {
1522     return (_jvms == NULL);
1523   }
1524 
1525   // Make there be nothing here.
1526   void clear() {
1527     _jvms = NULL;
1528   }
1529 
1530   // Make a new, clean node notes.
1531   static Node_Notes* make(Compile* C) {
1532     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1533     nn->clear();
1534     return nn;
1535   }
1536 
1537   Node_Notes* clone(Compile* C) {
1538     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1539     (*nn) = (*this);
1540     return nn;
1541   }
1542 
1543   // Absorb any information from source.
1544   bool update_from(Node_Notes* source) {
1545     bool changed = false;
1546     if (source != NULL) {
1547       if (source->jvms() != NULL) {
1548         set_jvms(source->jvms());
1549         changed = true;
1550       }
1551     }
1552     return changed;
1553   }
1554 };
1555 
1556 // Inlined accessors for Compile::node_nodes that require the preceding class:
1557 inline Node_Notes*
1558 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
1559                            int idx, bool can_grow) {
1560   assert(idx >= 0, "oob");
1561   int block_idx = (idx >> _log2_node_notes_block_size);
1562   int grow_by = (block_idx - (arr == NULL? 0: arr->length()));
1563   if (grow_by >= 0) {
1564     if (!can_grow)  return NULL;
1565     grow_node_notes(arr, grow_by + 1);
1566   }
1567   // (Every element of arr is a sub-array of length _node_notes_block_size.)
1568   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
1569 }
1570 
1571 inline bool
1572 Compile::set_node_notes_at(int idx, Node_Notes* value) {
1573   if (value == NULL || value->is_clear())
1574     return false;  // nothing to write => write nothing
1575   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
1576   assert(loc != NULL, "");
1577   return loc->update_from(value);
1578 }
1579 
1580 
1581 //------------------------------TypeNode---------------------------------------
1582 // Node with a Type constant.
1583 class TypeNode : public Node {
1584 protected:
1585   virtual uint hash() const;    // Check the type
1586   virtual uint cmp( const Node &n ) const;
1587   virtual uint size_of() const; // Size is bigger
1588   const Type* const _type;
1589 public:
1590   void set_type(const Type* t) {
1591     assert(t != NULL, "sanity");
1592     debug_only(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
1593     *(const Type**)&_type = t;   // cast away const-ness
1594     // If this node is in the hash table, make sure it doesn't need a rehash.
1595     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
1596   }
1597   const Type* type() const { assert(_type != NULL, "sanity"); return _type; };
1598   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
1599     init_class_id(Class_Type);
1600   }
1601   virtual const Type *Value( PhaseTransform *phase ) const;
1602   virtual const Type *bottom_type() const;
1603   virtual       uint  ideal_reg() const;
1604 #ifndef PRODUCT
1605   virtual void dump_spec(outputStream *st) const;
1606 #endif
1607 };
1608 
1609 #endif // SHARE_VM_OPTO_NODE_HPP