1 /*
   2  * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2024, 2025, Alibaba Group Holding Limited. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #ifndef SHARE_OPTO_NODE_HPP
  27 #define SHARE_OPTO_NODE_HPP
  28 
  29 #include "libadt/vectset.hpp"
  30 #include "opto/compile.hpp"
  31 #include "opto/type.hpp"
  32 #include "utilities/copy.hpp"
  33 
  34 // Portions of code courtesy of Clifford Click
  35 
  36 // Optimization - Graph Style
  37 
  38 
  39 class AbstractLockNode;
  40 class AddNode;
  41 class AddPNode;
  42 class AliasInfo;
  43 class AllocateArrayNode;
  44 class AllocateNode;
  45 class ArrayCopyNode;
  46 class BaseCountedLoopNode;
  47 class BaseCountedLoopEndNode;
  48 class BlackholeNode;
  49 class Block;
  50 class BoolNode;
  51 class BoxLockNode;
  52 class CMoveNode;
  53 class CallDynamicJavaNode;
  54 class CallJavaNode;
  55 class CallLeafNode;
  56 class CallLeafNoFPNode;
  57 class CallLeafPureNode;
  58 class CallNode;
  59 class CallRuntimeNode;
  60 class CallStaticJavaNode;
  61 class CastFFNode;
  62 class CastHHNode;
  63 class CastDDNode;
  64 class CastVVNode;
  65 class CastIINode;
  66 class CastLLNode;
  67 class CastPPNode;
  68 class CatchNode;
  69 class CatchProjNode;
  70 class CheckCastPPNode;
  71 class ClearArrayNode;
  72 class CmpNode;
  73 class CodeBuffer;
  74 class ConstraintCastNode;
  75 class ConNode;
  76 class ConINode;
  77 class ConvertNode;
  78 class CompareAndSwapNode;
  79 class CompareAndExchangeNode;
  80 class CountedLoopNode;
  81 class CountedLoopEndNode;
  82 class DecodeNarrowPtrNode;
  83 class DecodeNNode;
  84 class DecodeNKlassNode;
  85 class EncodeNarrowPtrNode;
  86 class EncodePNode;
  87 class EncodePKlassNode;
  88 class FastLockNode;
  89 class FastUnlockNode;
  90 class HaltNode;
  91 class IfNode;
  92 class IfProjNode;
  93 class IfFalseNode;
  94 class IfTrueNode;
  95 class InitializeNode;
  96 class JVMState;
  97 class JumpNode;
  98 class JumpProjNode;
  99 class LoadNode;
 100 class LoadStoreNode;
 101 class LoadStoreConditionalNode;
 102 class LockNode;
 103 class LongCountedLoopNode;
 104 class LongCountedLoopEndNode;
 105 class LoopNode;
 106 class LShiftNode;
 107 class MachBranchNode;
 108 class MachCallDynamicJavaNode;
 109 class MachCallJavaNode;
 110 class MachCallLeafNode;
 111 class MachCallNode;
 112 class MachCallRuntimeNode;
 113 class MachCallStaticJavaNode;
 114 class MachConstantBaseNode;
 115 class MachConstantNode;
 116 class MachGotoNode;
 117 class MachIfNode;
 118 class MachJumpNode;
 119 class MachNode;
 120 class MachNullCheckNode;
 121 class MachProjNode;
 122 class MachReturnNode;
 123 class MachSafePointNode;
 124 class MachSpillCopyNode;
 125 class MachTempNode;
 126 class MachMergeNode;
 127 class MachMemBarNode;
 128 class Matcher;
 129 class MemBarNode;
 130 class MemBarStoreStoreNode;
 131 class MemNode;
 132 class MergeMemNode;
 133 class MoveNode;
 134 class MulNode;
 135 class MultiNode;
 136 class MultiBranchNode;
 137 class NarrowMemProjNode;
 138 class NegNode;
 139 class NegVNode;
 140 class NeverBranchNode;
 141 class Opaque1Node;
 142 class OpaqueLoopInitNode;
 143 class OpaqueLoopStrideNode;
 144 class OpaqueMultiversioningNode;
 145 class OpaqueNotNullNode;
 146 class OpaqueInitializedAssertionPredicateNode;
 147 class OpaqueTemplateAssertionPredicateNode;
 148 class OuterStripMinedLoopNode;
 149 class OuterStripMinedLoopEndNode;
 150 class Node;
 151 class Node_Array;
 152 class Node_List;
 153 class Node_Stack;
 154 class OopMap;
 155 class ParmNode;
 156 class ParsePredicateNode;
 157 class PCTableNode;
 158 class PhaseCCP;
 159 class PhaseGVN;
 160 class PhaseIdealLoop;
 161 class PhaseIterGVN;
 162 class PhaseRegAlloc;
 163 class PhaseTransform;
 164 class PhaseValues;
 165 class PhiNode;
 166 class Pipeline;
 167 class PopulateIndexNode;
 168 class ProjNode;
 169 class RangeCheckNode;
 170 class ReductionNode;
 171 class RegMask;
 172 class RegionNode;
 173 class RootNode;
 174 class SafePointNode;
 175 class SafePointScalarObjectNode;
 176 class SafePointScalarMergeNode;
 177 class SaturatingVectorNode;
 178 class StartNode;
 179 class State;
 180 class StoreNode;
 181 class SubNode;
 182 class SubTypeCheckNode;
 183 class Type;
 184 class TypeNode;
 185 class UnlockNode;
 186 class VectorNode;
 187 class LoadVectorNode;
 188 class LoadVectorMaskedNode;
 189 class StoreVectorMaskedNode;
 190 class LoadVectorGatherNode;
 191 class LoadVectorGatherMaskedNode;
 192 class StoreVectorNode;
 193 class StoreVectorScatterNode;
 194 class StoreVectorScatterMaskedNode;
 195 class VerifyVectorAlignmentNode;
 196 class VectorMaskCmpNode;
 197 class VectorUnboxNode;
 198 class VectorSet;
 199 class VectorReinterpretNode;
 200 class ShiftVNode;
 201 class MulVLNode;
 202 class ExpandVNode;
 203 class CompressVNode;
 204 class CompressMNode;
 205 class C2_MacroAssembler;
 206 
 207 
 208 #ifndef OPTO_DU_ITERATOR_ASSERT
 209 #ifdef ASSERT
 210 #define OPTO_DU_ITERATOR_ASSERT 1
 211 #else
 212 #define OPTO_DU_ITERATOR_ASSERT 0
 213 #endif
 214 #endif //OPTO_DU_ITERATOR_ASSERT
 215 
 216 #if OPTO_DU_ITERATOR_ASSERT
 217 class DUIterator;
 218 class DUIterator_Fast;
 219 class DUIterator_Last;
 220 #else
 221 typedef uint   DUIterator;
 222 typedef Node** DUIterator_Fast;
 223 typedef Node** DUIterator_Last;
 224 #endif
 225 
 226 typedef ResizeableHashTable<Node*, Node*, AnyObj::RESOURCE_AREA, mtCompiler> OrigToNewHashtable;
 227 
 228 // Node Sentinel
 229 #define NodeSentinel (Node*)-1
 230 
 231 // Unknown count frequency
 232 #define COUNT_UNKNOWN (-1.0f)
 233 
 234 //------------------------------Node-------------------------------------------
 235 // Nodes define actions in the program.  They create values, which have types.
 236 // They are both vertices in a directed graph and program primitives.  Nodes
 237 // are labeled; the label is the "opcode", the primitive function in the lambda
 238 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 239 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 240 // the Node's function.  These inputs also define a Type equation for the Node.
 241 // Solving these Type equations amounts to doing dataflow analysis.
 242 // Control and data are uniformly represented in the graph.  Finally, Nodes
 243 // have a unique dense integer index which is used to index into side arrays
 244 // whenever I have phase-specific information.
 245 
 246 class Node {
 247 
 248   // Lots of restrictions on cloning Nodes
 249   NONCOPYABLE(Node);
 250 
 251 public:
 252   friend class Compile;
 253   #if OPTO_DU_ITERATOR_ASSERT
 254   friend class DUIterator_Common;
 255   friend class DUIterator;
 256   friend class DUIterator_Fast;
 257   friend class DUIterator_Last;
 258   #endif
 259 
 260   // Because Nodes come and go, I define an Arena of Node structures to pull
 261   // from.  This should allow fast access to node creation & deletion.  This
 262   // field is a local cache of a value defined in some "program fragment" for
 263   // which these Nodes are just a part of.
 264 
 265   inline void* operator new(size_t x) throw() {
 266     Compile* C = Compile::current();
 267     Node* n = (Node*)C->node_arena()->AmallocWords(x);
 268     return (void*)n;
 269   }
 270 
 271   // Delete is a NOP
 272   void operator delete( void *ptr ) {}
 273   // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 274   void destruct(PhaseValues* phase);
 275 
 276   // Create a new Node.  Required is the number is of inputs required for
 277   // semantic correctness.
 278   Node( uint required );
 279 
 280   // Create a new Node with given input edges.
 281   // This version requires use of the "edge-count" new.
 282   // E.g.  new (C,3) FooNode( C, nullptr, left, right );
 283   Node( Node *n0 );
 284   Node( Node *n0, Node *n1 );
 285   Node( Node *n0, Node *n1, Node *n2 );
 286   Node( Node *n0, Node *n1, Node *n2, Node *n3 );
 287   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
 288   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
 289   Node( Node *n0, Node *n1, Node *n2, Node *n3,
 290             Node *n4, Node *n5, Node *n6 );
 291 
 292   // Clone an inherited Node given only the base Node type.
 293   Node* clone() const;
 294 
 295   // Clone a Node, immediately supplying one or two new edges.
 296   // The first and second arguments, if non-null, replace in(1) and in(2),
 297   // respectively.
 298   Node* clone_with_data_edge(Node* in1, Node* in2 = nullptr) const {
 299     Node* nn = clone();
 300     if (in1 != nullptr)  nn->set_req(1, in1);
 301     if (in2 != nullptr)  nn->set_req(2, in2);
 302     return nn;
 303   }
 304 
 305 private:
 306   // Shared setup for the above constructors.
 307   // Handles all interactions with Compile::current.
 308   // Puts initial values in all Node fields except _idx.
 309   // Returns the initial value for _idx, which cannot
 310   // be initialized by assignment.
 311   inline int Init(int req);
 312 
 313 //----------------- input edge handling
 314 protected:
 315   friend class PhaseCFG;        // Access to address of _in array elements
 316   Node **_in;                   // Array of use-def references to Nodes
 317   Node **_out;                  // Array of def-use references to Nodes
 318 
 319   // Input edges are split into two categories.  Required edges are required
 320   // for semantic correctness; order is important and nulls are allowed.
 321   // Precedence edges are used to help determine execution order and are
 322   // added, e.g., for scheduling purposes.  They are unordered and not
 323   // duplicated; they have no embedded nulls.  Edges from 0 to _cnt-1
 324   // are required, from _cnt to _max-1 are precedence edges.
 325   node_idx_t _cnt;              // Total number of required Node inputs.
 326 
 327   node_idx_t _max;              // Actual length of input array.
 328 
 329   // Output edges are an unordered list of def-use edges which exactly
 330   // correspond to required input edges which point from other nodes
 331   // to this one.  Thus the count of the output edges is the number of
 332   // users of this node.
 333   node_idx_t _outcnt;           // Total number of Node outputs.
 334 
 335   node_idx_t _outmax;           // Actual length of output array.
 336 
 337   // Grow the actual input array to the next larger power-of-2 bigger than len.
 338   void grow( uint len );
 339   // Grow the output array to the next larger power-of-2 bigger than len.
 340   void out_grow( uint len );
 341   // Resize input or output array to grow it to the next larger power-of-2
 342   // bigger than len.
 343   void resize_array(Node**& array, node_idx_t& max_size, uint len, bool needs_clearing);
 344 
 345 public:
 346   // Each Node is assigned a unique small/dense number. This number is used
 347   // to index into auxiliary arrays of data and bit vectors.
 348   // The value of _idx can be changed using the set_idx() method.
 349   //
 350   // The PhaseRenumberLive phase renumbers nodes based on liveness information.
 351   // Therefore, it updates the value of the _idx field. The parse-time _idx is
 352   // preserved in _parse_idx.
 353   node_idx_t _idx;
 354   DEBUG_ONLY(const node_idx_t _parse_idx;)
 355   // IGV node identifier. Two nodes, possibly in different compilation phases,
 356   // have the same IGV identifier if (and only if) they are the very same node
 357   // (same memory address) or one is "derived" from the other (by e.g.
 358   // renumbering or matching). This identifier makes it possible to follow the
 359   // entire lifetime of a node in IGV even if its C2 identifier (_idx) changes.
 360   NOT_PRODUCT(node_idx_t _igv_idx;)
 361 
 362   // Get the (read-only) number of input edges
 363   uint req() const { return _cnt; }
 364   uint len() const { return _max; }
 365   // Get the (read-only) number of output edges
 366   uint outcnt() const { return _outcnt; }
 367 
 368 #if OPTO_DU_ITERATOR_ASSERT
 369   // Iterate over the out-edges of this node.  Deletions are illegal.
 370   inline DUIterator outs() const;
 371   // Use this when the out array might have changed to suppress asserts.
 372   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 373   // Does the node have an out at this position?  (Used for iteration.)
 374   inline bool has_out(DUIterator& i) const;
 375   inline Node*    out(DUIterator& i) const;
 376   // Iterate over the out-edges of this node.  All changes are illegal.
 377   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 378   inline Node*    fast_out(DUIterator_Fast& i) const;
 379   // Iterate over the out-edges of this node, deleting one at a time.
 380   inline DUIterator_Last last_outs(DUIterator_Last& min) const;
 381   inline Node*    last_out(DUIterator_Last& i) const;
 382   // The inline bodies of all these methods are after the iterator definitions.
 383 #else
 384   // Iterate over the out-edges of this node.  Deletions are illegal.
 385   // This iteration uses integral indexes, to decouple from array reallocations.
 386   DUIterator outs() const  { return 0; }
 387   // Use this when the out array might have changed to suppress asserts.
 388   DUIterator refresh_out_pos(DUIterator i) const { return i; }
 389 
 390   // Reference to the i'th output Node.  Error if out of bounds.
 391   Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
 392   // Does the node have an out at this position?  (Used for iteration.)
 393   bool has_out(DUIterator i) const { return i < _outcnt; }
 394 
 395   // Iterate over the out-edges of this node.  All changes are illegal.
 396   // This iteration uses a pointer internal to the out array.
 397   DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
 398     Node** out = _out;
 399     // Assign a limit pointer to the reference argument:
 400     max = out + (ptrdiff_t)_outcnt;
 401     // Return the base pointer:
 402     return out;
 403   }
 404   Node*    fast_out(DUIterator_Fast i) const  { return *i; }
 405   // Iterate over the out-edges of this node, deleting one at a time.
 406   // This iteration uses a pointer internal to the out array.
 407   DUIterator_Last last_outs(DUIterator_Last& min) const {
 408     Node** out = _out;
 409     // Assign a limit pointer to the reference argument:
 410     min = out;
 411     // Return the pointer to the start of the iteration:
 412     return out + (ptrdiff_t)_outcnt - 1;
 413   }
 414   Node*    last_out(DUIterator_Last i) const  { return *i; }
 415 #endif
 416 
 417   // Reference to the i'th input Node.  Error if out of bounds.
 418   Node* in(uint i) const { assert(i < _max, "oob: i=%d, _max=%d", i, _max); return _in[i]; }
 419   // Reference to the i'th input Node.  null if out of bounds.
 420   Node* lookup(uint i) const { return ((i < _max) ? _in[i] : nullptr); }
 421   // Reference to the i'th output Node.  Error if out of bounds.
 422   // Use this accessor sparingly.  We are going trying to use iterators instead.
 423   Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
 424   // Return the unique out edge.
 425   Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
 426 
 427   // In some cases, a node n is only used by a single use, but the use may use
 428   // n once or multiple times:
 429   //   use = ConvF2I(this)
 430   //   use = AddI(this, this)
 431   Node* unique_multiple_edges_out_or_null() const;
 432 
 433   // Delete out edge at position 'i' by moving last out edge to position 'i'
 434   void  raw_del_out(uint i) {
 435     assert(i < _outcnt,"oob");
 436     assert(_outcnt > 0,"oob");
 437     #if OPTO_DU_ITERATOR_ASSERT
 438     // Record that a change happened here.
 439     DEBUG_ONLY(_last_del = _out[i]; ++_del_tick);
 440     #endif
 441     _out[i] = _out[--_outcnt];
 442     // Smash the old edge so it can't be used accidentally.
 443     DEBUG_ONLY(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 444   }
 445 
 446 #ifdef ASSERT
 447   bool is_dead() const;
 448   static bool is_not_dead(const Node* n);
 449   bool is_reachable_from_root() const;
 450 #endif
 451   // Check whether node has become unreachable
 452   bool is_unreachable(PhaseIterGVN &igvn) const;
 453 
 454   // Set a required input edge, also updates corresponding output edge
 455   void add_req( Node *n ); // Append a NEW required input
 456   void add_req( Node *n0, Node *n1 ) {
 457     add_req(n0); add_req(n1); }
 458   void add_req( Node *n0, Node *n1, Node *n2 ) {
 459     add_req(n0); add_req(n1); add_req(n2); }
 460   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 461   void del_req( uint idx ); // Delete required edge & compact
 462   void del_req_ordered( uint idx ); // Delete required edge & compact with preserved order
 463   void ins_req( uint i, Node *n ); // Insert a NEW required input
 464   void set_req( uint i, Node *n ) {
 465     assert( is_not_dead(n), "can not use dead node");
 466     assert( i < _cnt, "oob: i=%d, _cnt=%d", i, _cnt);
 467     assert( !VerifyHashTableKeys || _hash_lock == 0,
 468             "remove node from hash table before modifying it");
 469     Node** p = &_in[i];    // cache this._in, across the del_out call
 470     if (*p != nullptr)  (*p)->del_out((Node *)this);
 471     (*p) = n;
 472     if (n != nullptr)      n->add_out((Node *)this);
 473     Compile::current()->record_modified_node(this);
 474   }
 475   // Light version of set_req() to init inputs after node creation.
 476   void init_req( uint i, Node *n ) {
 477     assert( (i == 0 && this == n) ||
 478             is_not_dead(n), "can not use dead node");
 479     assert( i < _cnt, "oob");
 480     assert( !VerifyHashTableKeys || _hash_lock == 0,
 481             "remove node from hash table before modifying it");
 482     assert( _in[i] == nullptr, "sanity");
 483     _in[i] = n;
 484     if (n != nullptr)      n->add_out((Node *)this);
 485     Compile::current()->record_modified_node(this);
 486   }
 487   // Find first occurrence of n among my edges:
 488   int find_edge(Node* n);
 489   int find_prec_edge(Node* n) {
 490     for (uint i = req(); i < len(); i++) {
 491       if (_in[i] == n) return i;
 492       if (_in[i] == nullptr) {
 493         DEBUG_ONLY( while ((++i) < len()) assert(_in[i] == nullptr, "Gap in prec edges!"); )
 494         break;
 495       }
 496     }
 497     return -1;
 498   }
 499   int replace_edge(Node* old, Node* neww, PhaseGVN* gvn = nullptr);
 500   int replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn);
 501   // null out all inputs to eliminate incoming Def-Use edges.
 502   void disconnect_inputs(Compile* C);
 503 
 504   // Quickly, return true if and only if I am Compile::current()->top().
 505   bool is_top() const {
 506     assert((this == (Node*) Compile::current()->top()) == (_out == nullptr), "");
 507     return (_out == nullptr);
 508   }
 509   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 510   void setup_is_top();
 511 
 512   // Strip away casting.  (It is depth-limited.)
 513   Node* uncast(bool keep_deps = false) const;
 514   // Return whether two Nodes are equivalent, after stripping casting.
 515   bool eqv_uncast(const Node* n, bool keep_deps = false) const {
 516     return (this->uncast(keep_deps) == n->uncast(keep_deps));
 517   }
 518 
 519   // Find out of current node that matches opcode.
 520   Node* find_out_with(int opcode);
 521   // Return true if the current node has an out that matches opcode.
 522   bool has_out_with(int opcode);
 523   // Return true if the current node has an out that matches any of the opcodes.
 524   bool has_out_with(int opcode1, int opcode2, int opcode3, int opcode4);
 525 
 526 private:
 527   static Node* uncast_helper(const Node* n, bool keep_deps);
 528 
 529   // Add an output edge to the end of the list
 530   void add_out( Node *n ) {
 531     if (is_top())  return;
 532     if( _outcnt == _outmax ) out_grow(_outcnt);
 533     _out[_outcnt++] = n;
 534   }
 535   // Delete an output edge
 536   void del_out( Node *n ) {
 537     if (is_top())  return;
 538     Node** outp = &_out[_outcnt];
 539     // Find and remove n
 540     do {
 541       assert(outp > _out, "Missing Def-Use edge");
 542     } while (*--outp != n);
 543     *outp = _out[--_outcnt];
 544     // Smash the old edge so it can't be used accidentally.
 545     DEBUG_ONLY(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 546     // Record that a change happened here.
 547     #if OPTO_DU_ITERATOR_ASSERT
 548     DEBUG_ONLY(_last_del = n; ++_del_tick);
 549     #endif
 550   }
 551   // Close gap after removing edge.
 552   void close_prec_gap_at(uint gap) {
 553     assert(_cnt <= gap && gap < _max, "no valid prec edge");
 554     uint i = gap;
 555     Node *last = nullptr;
 556     for (; i < _max-1; ++i) {
 557       Node *next = _in[i+1];
 558       if (next == nullptr) break;
 559       last = next;
 560     }
 561     _in[gap] = last;  // Move last slot to empty one.
 562     _in[i] = nullptr; // null out last slot.
 563   }
 564 
 565 public:
 566   // Globally replace this node by a given new node, updating all uses.
 567   void replace_by(Node* new_node);
 568   // Globally replace this node by a given new node, updating all uses
 569   // and cutting input edges of old node.
 570   void subsume_by(Node* new_node, Compile* c) {
 571     replace_by(new_node);
 572     disconnect_inputs(c);
 573   }
 574   void set_req_X(uint i, Node *n, PhaseIterGVN *igvn);
 575   void set_req_X(uint i, Node *n, PhaseGVN *gvn);
 576   // Find the one non-null required input.  RegionNode only
 577   Node *nonnull_req() const;
 578   // Add or remove precedence edges
 579   void add_prec( Node *n );
 580   void rm_prec( uint i );
 581 
 582   // Note: prec(i) will not necessarily point to n if edge already exists.
 583   void set_prec( uint i, Node *n ) {
 584     assert(i < _max, "oob: i=%d, _max=%d", i, _max);
 585     assert(is_not_dead(n), "can not use dead node");
 586     assert(i >= _cnt, "not a precedence edge");
 587     // Avoid spec violation: duplicated prec edge.
 588     if (_in[i] == n) return;
 589     if (n == nullptr || find_prec_edge(n) != -1) {
 590       rm_prec(i);
 591       return;
 592     }
 593     if (_in[i] != nullptr) _in[i]->del_out((Node *)this);
 594     _in[i] = n;
 595     n->add_out((Node *)this);
 596     Compile::current()->record_modified_node(this);
 597   }
 598 
 599   // Set this node's index, used by cisc_version to replace current node
 600   void set_idx(uint new_idx) {
 601     _idx = new_idx;
 602   }
 603   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 604   void swap_edges(uint i1, uint i2) {
 605     DEBUG_ONLY(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 606     // Def-Use info is unchanged
 607     Node* n1 = in(i1);
 608     Node* n2 = in(i2);
 609     _in[i1] = n2;
 610     _in[i2] = n1;
 611     // If this node is in the hash table, make sure it doesn't need a rehash.
 612     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 613     // Flip swapped edges flag.
 614     if (has_swapped_edges()) {
 615       remove_flag(Node::Flag_has_swapped_edges);
 616     } else {
 617       add_flag(Node::Flag_has_swapped_edges);
 618     }
 619   }
 620 
 621   // Iterators over input Nodes for a Node X are written as:
 622   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 623   // NOTE: Required edges can contain embedded null pointers.
 624 
 625 //----------------- Other Node Properties
 626 
 627   // Generate class IDs for (some) ideal nodes so that it is possible to determine
 628   // the type of a node using a non-virtual method call (the method is_<Node>() below).
 629   //
 630   // A class ID of an ideal node is a set of bits. In a class ID, a single bit determines
 631   // the type of the node the ID represents; another subset of an ID's bits are reserved
 632   // for the superclasses of the node represented by the ID.
 633   //
 634   // By design, if A is a supertype of B, A.is_B() returns true and B.is_A()
 635   // returns false. A.is_A() returns true.
 636   //
 637   // If two classes, A and B, have the same superclass, a different bit of A's class id
 638   // is reserved for A's type than for B's type. That bit is specified by the third
 639   // parameter in the macro DEFINE_CLASS_ID.
 640   //
 641   // By convention, classes with deeper hierarchy are declared first. Moreover,
 642   // classes with the same hierarchy depth are sorted by usage frequency.
 643   //
 644   // The query method masks the bits to cut off bits of subclasses and then compares
 645   // the result with the class id (see the macro DEFINE_CLASS_QUERY below).
 646   //
 647   //  Class_MachCall=30, ClassMask_MachCall=31
 648   // 12               8               4               0
 649   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 650   //                                  |   |   |   |
 651   //                                  |   |   |   Bit_Mach=2
 652   //                                  |   |   Bit_MachReturn=4
 653   //                                  |   Bit_MachSafePoint=8
 654   //                                  Bit_MachCall=16
 655   //
 656   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 657   // 12               8               4               0
 658   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 659   //                              |   |   |
 660   //                              |   |   Bit_Region=8
 661   //                              |   Bit_Loop=16
 662   //                              Bit_CountedLoop=32
 663 
 664   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 665   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 666   Class_##cl = Class_##supcl + Bit_##cl , \
 667   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 668 
 669   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 670   // so that its values fit into 32 bits.
 671   enum NodeClasses {
 672     Bit_Node   = 0x00000000,
 673     Class_Node = 0x00000000,
 674     ClassMask_Node = 0xFFFFFFFF,
 675 
 676     DEFINE_CLASS_ID(Multi, Node, 0)
 677       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 678         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 679           DEFINE_CLASS_ID(CallJava,         Call, 0)
 680             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 681             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 682           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 683             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 684               DEFINE_CLASS_ID(CallLeafNoFP,     CallLeaf, 0)
 685               DEFINE_CLASS_ID(CallLeafPure,     CallLeaf, 1)
 686           DEFINE_CLASS_ID(Allocate,         Call, 2)
 687             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 688           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 689             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 690             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 691           DEFINE_CLASS_ID(ArrayCopy,        Call, 4)
 692       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 693         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 694           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 695           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 696         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 697           DEFINE_CLASS_ID(BaseCountedLoopEnd,     If, 0)
 698             DEFINE_CLASS_ID(CountedLoopEnd,       BaseCountedLoopEnd, 0)
 699             DEFINE_CLASS_ID(LongCountedLoopEnd,   BaseCountedLoopEnd, 1)
 700           DEFINE_CLASS_ID(RangeCheck,             If, 1)
 701           DEFINE_CLASS_ID(OuterStripMinedLoopEnd, If, 2)
 702           DEFINE_CLASS_ID(ParsePredicate,         If, 3)
 703         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 704       DEFINE_CLASS_ID(Start,       Multi, 2)
 705       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 706         DEFINE_CLASS_ID(Initialize,       MemBar, 0)
 707         DEFINE_CLASS_ID(MemBarStoreStore, MemBar, 1)
 708 
 709     DEFINE_CLASS_ID(Mach,  Node, 1)
 710       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 711         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 712           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 713             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 714               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 715               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 716             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 717               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 718       DEFINE_CLASS_ID(MachBranch, Mach, 1)
 719         DEFINE_CLASS_ID(MachIf,         MachBranch, 0)
 720         DEFINE_CLASS_ID(MachGoto,       MachBranch, 1)
 721         DEFINE_CLASS_ID(MachNullCheck,  MachBranch, 2)
 722       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 2)
 723       DEFINE_CLASS_ID(MachTemp,         Mach, 3)
 724       DEFINE_CLASS_ID(MachConstantBase, Mach, 4)
 725       DEFINE_CLASS_ID(MachConstant,     Mach, 5)
 726         DEFINE_CLASS_ID(MachJump,       MachConstant, 0)
 727       DEFINE_CLASS_ID(MachMerge,        Mach, 6)
 728       DEFINE_CLASS_ID(MachMemBar,       Mach, 7)
 729 
 730     DEFINE_CLASS_ID(Type,  Node, 2)
 731       DEFINE_CLASS_ID(Phi,   Type, 0)
 732       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 733         DEFINE_CLASS_ID(CastII, ConstraintCast, 0)
 734         DEFINE_CLASS_ID(CheckCastPP, ConstraintCast, 1)
 735         DEFINE_CLASS_ID(CastLL, ConstraintCast, 2)
 736         DEFINE_CLASS_ID(CastFF, ConstraintCast, 3)
 737         DEFINE_CLASS_ID(CastDD, ConstraintCast, 4)
 738         DEFINE_CLASS_ID(CastVV, ConstraintCast, 5)
 739         DEFINE_CLASS_ID(CastPP, ConstraintCast, 6)
 740         DEFINE_CLASS_ID(CastHH, ConstraintCast, 7)
 741       DEFINE_CLASS_ID(CMove, Type, 3)
 742       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 743       DEFINE_CLASS_ID(DecodeNarrowPtr, Type, 5)
 744         DEFINE_CLASS_ID(DecodeN, DecodeNarrowPtr, 0)
 745         DEFINE_CLASS_ID(DecodeNKlass, DecodeNarrowPtr, 1)
 746       DEFINE_CLASS_ID(EncodeNarrowPtr, Type, 6)
 747         DEFINE_CLASS_ID(EncodeP, EncodeNarrowPtr, 0)
 748         DEFINE_CLASS_ID(EncodePKlass, EncodeNarrowPtr, 1)
 749       DEFINE_CLASS_ID(Vector, Type, 7)
 750         DEFINE_CLASS_ID(VectorMaskCmp, Vector, 0)
 751         DEFINE_CLASS_ID(VectorUnbox, Vector, 1)
 752         DEFINE_CLASS_ID(VectorReinterpret, Vector, 2)
 753         DEFINE_CLASS_ID(ShiftV, Vector, 3)
 754         DEFINE_CLASS_ID(CompressV, Vector, 4)
 755         DEFINE_CLASS_ID(ExpandV, Vector, 5)
 756         DEFINE_CLASS_ID(CompressM, Vector, 6)
 757         DEFINE_CLASS_ID(Reduction, Vector, 7)
 758         DEFINE_CLASS_ID(NegV, Vector, 8)
 759         DEFINE_CLASS_ID(SaturatingVector, Vector, 9)
 760         DEFINE_CLASS_ID(MulVL, Vector, 10)
 761       DEFINE_CLASS_ID(Con, Type, 8)
 762           DEFINE_CLASS_ID(ConI, Con, 0)
 763       DEFINE_CLASS_ID(SafePointScalarMerge, Type, 9)
 764       DEFINE_CLASS_ID(Convert, Type, 10)
 765 
 766 
 767     DEFINE_CLASS_ID(Proj,  Node, 3)
 768       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 769       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 770       DEFINE_CLASS_ID(IfProj,    Proj, 2)
 771         DEFINE_CLASS_ID(IfTrue,    IfProj, 0)
 772         DEFINE_CLASS_ID(IfFalse,   IfProj, 1)
 773       DEFINE_CLASS_ID(Parm,      Proj, 4)
 774       DEFINE_CLASS_ID(MachProj,  Proj, 5)
 775       DEFINE_CLASS_ID(NarrowMemProj, Proj, 6)
 776 
 777     DEFINE_CLASS_ID(Mem, Node, 4)
 778       DEFINE_CLASS_ID(Load, Mem, 0)
 779         DEFINE_CLASS_ID(LoadVector,  Load, 0)
 780           DEFINE_CLASS_ID(LoadVectorGather, LoadVector, 0)
 781           DEFINE_CLASS_ID(LoadVectorGatherMasked, LoadVector, 1)
 782           DEFINE_CLASS_ID(LoadVectorMasked, LoadVector, 2)
 783       DEFINE_CLASS_ID(Store, Mem, 1)
 784         DEFINE_CLASS_ID(StoreVector, Store, 0)
 785           DEFINE_CLASS_ID(StoreVectorScatter, StoreVector, 0)
 786           DEFINE_CLASS_ID(StoreVectorScatterMasked, StoreVector, 1)
 787           DEFINE_CLASS_ID(StoreVectorMasked, StoreVector, 2)
 788       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 789         DEFINE_CLASS_ID(LoadStoreConditional, LoadStore, 0)
 790           DEFINE_CLASS_ID(CompareAndSwap, LoadStoreConditional, 0)
 791         DEFINE_CLASS_ID(CompareAndExchangeNode, LoadStore, 1)
 792 
 793     DEFINE_CLASS_ID(Region, Node, 5)
 794       DEFINE_CLASS_ID(Loop, Region, 0)
 795         DEFINE_CLASS_ID(Root,                Loop, 0)
 796         DEFINE_CLASS_ID(BaseCountedLoop,     Loop, 1)
 797           DEFINE_CLASS_ID(CountedLoop,       BaseCountedLoop, 0)
 798           DEFINE_CLASS_ID(LongCountedLoop,   BaseCountedLoop, 1)
 799         DEFINE_CLASS_ID(OuterStripMinedLoop, Loop, 2)
 800 
 801     DEFINE_CLASS_ID(Sub,   Node, 6)
 802       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 803         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
 804         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
 805         DEFINE_CLASS_ID(SubTypeCheck,Cmp, 2)
 806 
 807     DEFINE_CLASS_ID(MergeMem, Node, 7)
 808     DEFINE_CLASS_ID(Bool,     Node, 8)
 809     DEFINE_CLASS_ID(AddP,     Node, 9)
 810     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 811     DEFINE_CLASS_ID(Add,      Node, 11)
 812     DEFINE_CLASS_ID(Mul,      Node, 12)
 813     DEFINE_CLASS_ID(ClearArray, Node, 14)
 814     DEFINE_CLASS_ID(Halt,     Node, 15)
 815     DEFINE_CLASS_ID(Opaque1,  Node, 16)
 816       DEFINE_CLASS_ID(OpaqueLoopInit, Opaque1, 0)
 817       DEFINE_CLASS_ID(OpaqueLoopStride, Opaque1, 1)
 818       DEFINE_CLASS_ID(OpaqueMultiversioning, Opaque1, 2)
 819     DEFINE_CLASS_ID(OpaqueNotNull,  Node, 17)
 820     DEFINE_CLASS_ID(OpaqueInitializedAssertionPredicate,  Node, 18)
 821     DEFINE_CLASS_ID(OpaqueTemplateAssertionPredicate,  Node, 19)
 822     DEFINE_CLASS_ID(Move,     Node, 20)
 823     DEFINE_CLASS_ID(LShift,   Node, 21)
 824     DEFINE_CLASS_ID(Neg,      Node, 22)
 825 
 826     _max_classes  = ClassMask_Neg
 827   };
 828   #undef DEFINE_CLASS_ID
 829 
 830   // Flags are sorted by usage frequency.
 831   enum NodeFlags {
 832     Flag_is_Copy                     = 1 << 0, // should be first bit to avoid shift
 833     Flag_rematerialize               = 1 << 1,
 834     Flag_needs_anti_dependence_check = 1 << 2,
 835     Flag_is_macro                    = 1 << 3,
 836     Flag_is_Con                      = 1 << 4,
 837     Flag_is_cisc_alternate           = 1 << 5,
 838     Flag_is_dead_loop_safe           = 1 << 6,
 839     Flag_may_be_short_branch         = 1 << 7,
 840     Flag_avoid_back_to_back_before   = 1 << 8,
 841     Flag_avoid_back_to_back_after    = 1 << 9,
 842     Flag_has_call                    = 1 << 10,
 843     Flag_has_swapped_edges           = 1 << 11,
 844     Flag_is_scheduled                = 1 << 12,
 845     Flag_is_expensive                = 1 << 13,
 846     Flag_is_predicated_vector        = 1 << 14,
 847     Flag_for_post_loop_opts_igvn     = 1 << 15,
 848     Flag_for_merge_stores_igvn       = 1 << 16,
 849     Flag_is_removed_by_peephole      = 1 << 17,
 850     Flag_is_predicated_using_blend   = 1 << 18,
 851     _last_flag                       = Flag_is_predicated_using_blend
 852   };
 853 
 854   class PD;
 855 
 856 private:
 857   juint _class_id;
 858   juint _flags;
 859 
 860 #ifdef ASSERT
 861   static juint max_flags();
 862 #endif
 863 
 864 protected:
 865   // These methods should be called from constructors only.
 866   void init_class_id(juint c) {
 867     _class_id = c; // cast out const
 868   }
 869   void init_flags(uint fl) {
 870     assert(fl <= max_flags(), "invalid node flag");
 871     _flags |= fl;
 872   }
 873   void clear_flag(uint fl) {
 874     assert(fl <= max_flags(), "invalid node flag");
 875     _flags &= ~fl;
 876   }
 877 
 878 public:
 879   juint class_id() const { return _class_id; }
 880 
 881   juint flags() const { return _flags; }
 882 
 883   void add_flag(juint fl) { init_flags(fl); }
 884 
 885   void remove_flag(juint fl) { clear_flag(fl); }
 886 
 887   // Return a dense integer opcode number
 888   virtual int Opcode() const;
 889 
 890   // Virtual inherited Node size
 891   virtual uint size_of() const;
 892 
 893   // Other interesting Node properties
 894   #define DEFINE_CLASS_QUERY(type)                           \
 895   bool is_##type() const {                                   \
 896     return ((_class_id & ClassMask_##type) == Class_##type); \
 897   }                                                          \
 898   type##Node *as_##type() const {                            \
 899     assert(is_##type(), "invalid node class: %s", Name());   \
 900     return (type##Node*)this;                                \
 901   }                                                          \
 902   type##Node* isa_##type() const {                           \
 903     return (is_##type()) ? as_##type() : nullptr;            \
 904   }
 905 
 906   DEFINE_CLASS_QUERY(AbstractLock)
 907   DEFINE_CLASS_QUERY(Add)
 908   DEFINE_CLASS_QUERY(AddP)
 909   DEFINE_CLASS_QUERY(Allocate)
 910   DEFINE_CLASS_QUERY(AllocateArray)
 911   DEFINE_CLASS_QUERY(ArrayCopy)
 912   DEFINE_CLASS_QUERY(BaseCountedLoop)
 913   DEFINE_CLASS_QUERY(BaseCountedLoopEnd)
 914   DEFINE_CLASS_QUERY(Bool)
 915   DEFINE_CLASS_QUERY(BoxLock)
 916   DEFINE_CLASS_QUERY(Call)
 917   DEFINE_CLASS_QUERY(CallDynamicJava)
 918   DEFINE_CLASS_QUERY(CallJava)
 919   DEFINE_CLASS_QUERY(CallLeaf)
 920   DEFINE_CLASS_QUERY(CallLeafNoFP)
 921   DEFINE_CLASS_QUERY(CallLeafPure)
 922   DEFINE_CLASS_QUERY(CallRuntime)
 923   DEFINE_CLASS_QUERY(CallStaticJava)
 924   DEFINE_CLASS_QUERY(Catch)
 925   DEFINE_CLASS_QUERY(CatchProj)
 926   DEFINE_CLASS_QUERY(CheckCastPP)
 927   DEFINE_CLASS_QUERY(CastII)
 928   DEFINE_CLASS_QUERY(CastLL)
 929   DEFINE_CLASS_QUERY(CastFF)
 930   DEFINE_CLASS_QUERY(ConI)
 931   DEFINE_CLASS_QUERY(CastPP)
 932   DEFINE_CLASS_QUERY(ConstraintCast)
 933   DEFINE_CLASS_QUERY(ClearArray)
 934   DEFINE_CLASS_QUERY(CMove)
 935   DEFINE_CLASS_QUERY(Cmp)
 936   DEFINE_CLASS_QUERY(Convert)
 937   DEFINE_CLASS_QUERY(CountedLoop)
 938   DEFINE_CLASS_QUERY(CountedLoopEnd)
 939   DEFINE_CLASS_QUERY(DecodeNarrowPtr)
 940   DEFINE_CLASS_QUERY(DecodeN)
 941   DEFINE_CLASS_QUERY(DecodeNKlass)
 942   DEFINE_CLASS_QUERY(EncodeNarrowPtr)
 943   DEFINE_CLASS_QUERY(EncodeP)
 944   DEFINE_CLASS_QUERY(EncodePKlass)
 945   DEFINE_CLASS_QUERY(FastLock)
 946   DEFINE_CLASS_QUERY(FastUnlock)
 947   DEFINE_CLASS_QUERY(Halt)
 948   DEFINE_CLASS_QUERY(If)
 949   DEFINE_CLASS_QUERY(RangeCheck)
 950   DEFINE_CLASS_QUERY(IfProj)
 951   DEFINE_CLASS_QUERY(IfFalse)
 952   DEFINE_CLASS_QUERY(IfTrue)
 953   DEFINE_CLASS_QUERY(Initialize)
 954   DEFINE_CLASS_QUERY(Jump)
 955   DEFINE_CLASS_QUERY(JumpProj)
 956   DEFINE_CLASS_QUERY(LongCountedLoop)
 957   DEFINE_CLASS_QUERY(LongCountedLoopEnd)
 958   DEFINE_CLASS_QUERY(Load)
 959   DEFINE_CLASS_QUERY(LoadStore)
 960   DEFINE_CLASS_QUERY(LoadStoreConditional)
 961   DEFINE_CLASS_QUERY(Lock)
 962   DEFINE_CLASS_QUERY(Loop)
 963   DEFINE_CLASS_QUERY(LShift)
 964   DEFINE_CLASS_QUERY(Mach)
 965   DEFINE_CLASS_QUERY(MachBranch)
 966   DEFINE_CLASS_QUERY(MachCall)
 967   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 968   DEFINE_CLASS_QUERY(MachCallJava)
 969   DEFINE_CLASS_QUERY(MachCallLeaf)
 970   DEFINE_CLASS_QUERY(MachCallRuntime)
 971   DEFINE_CLASS_QUERY(MachCallStaticJava)
 972   DEFINE_CLASS_QUERY(MachConstantBase)
 973   DEFINE_CLASS_QUERY(MachConstant)
 974   DEFINE_CLASS_QUERY(MachGoto)
 975   DEFINE_CLASS_QUERY(MachIf)
 976   DEFINE_CLASS_QUERY(MachJump)
 977   DEFINE_CLASS_QUERY(MachNullCheck)
 978   DEFINE_CLASS_QUERY(MachProj)
 979   DEFINE_CLASS_QUERY(MachReturn)
 980   DEFINE_CLASS_QUERY(MachSafePoint)
 981   DEFINE_CLASS_QUERY(MachSpillCopy)
 982   DEFINE_CLASS_QUERY(MachTemp)
 983   DEFINE_CLASS_QUERY(MachMemBar)
 984   DEFINE_CLASS_QUERY(MachMerge)
 985   DEFINE_CLASS_QUERY(Mem)
 986   DEFINE_CLASS_QUERY(MemBar)
 987   DEFINE_CLASS_QUERY(MemBarStoreStore)
 988   DEFINE_CLASS_QUERY(MergeMem)
 989   DEFINE_CLASS_QUERY(Move)
 990   DEFINE_CLASS_QUERY(Mul)
 991   DEFINE_CLASS_QUERY(Multi)
 992   DEFINE_CLASS_QUERY(MultiBranch)
 993   DEFINE_CLASS_QUERY(MulVL)
 994   DEFINE_CLASS_QUERY(NarrowMemProj)
 995   DEFINE_CLASS_QUERY(Neg)
 996   DEFINE_CLASS_QUERY(NegV)
 997   DEFINE_CLASS_QUERY(NeverBranch)
 998   DEFINE_CLASS_QUERY(Opaque1)
 999   DEFINE_CLASS_QUERY(OpaqueNotNull)
1000   DEFINE_CLASS_QUERY(OpaqueInitializedAssertionPredicate)
1001   DEFINE_CLASS_QUERY(OpaqueTemplateAssertionPredicate)
1002   DEFINE_CLASS_QUERY(OpaqueLoopInit)
1003   DEFINE_CLASS_QUERY(OpaqueLoopStride)
1004   DEFINE_CLASS_QUERY(OpaqueMultiversioning)
1005   DEFINE_CLASS_QUERY(OuterStripMinedLoop)
1006   DEFINE_CLASS_QUERY(OuterStripMinedLoopEnd)
1007   DEFINE_CLASS_QUERY(Parm)
1008   DEFINE_CLASS_QUERY(ParsePredicate)
1009   DEFINE_CLASS_QUERY(PCTable)
1010   DEFINE_CLASS_QUERY(Phi)
1011   DEFINE_CLASS_QUERY(Proj)
1012   DEFINE_CLASS_QUERY(Reduction)
1013   DEFINE_CLASS_QUERY(Region)
1014   DEFINE_CLASS_QUERY(Root)
1015   DEFINE_CLASS_QUERY(SafePoint)
1016   DEFINE_CLASS_QUERY(SafePointScalarObject)
1017   DEFINE_CLASS_QUERY(SafePointScalarMerge)
1018   DEFINE_CLASS_QUERY(Start)
1019   DEFINE_CLASS_QUERY(Store)
1020   DEFINE_CLASS_QUERY(Sub)
1021   DEFINE_CLASS_QUERY(SubTypeCheck)
1022   DEFINE_CLASS_QUERY(Type)
1023   DEFINE_CLASS_QUERY(Vector)
1024   DEFINE_CLASS_QUERY(VectorMaskCmp)
1025   DEFINE_CLASS_QUERY(VectorUnbox)
1026   DEFINE_CLASS_QUERY(VectorReinterpret)
1027   DEFINE_CLASS_QUERY(CompressV)
1028   DEFINE_CLASS_QUERY(ExpandV)
1029   DEFINE_CLASS_QUERY(CompressM)
1030   DEFINE_CLASS_QUERY(LoadVector)
1031   DEFINE_CLASS_QUERY(LoadVectorGather)
1032   DEFINE_CLASS_QUERY(LoadVectorMasked)
1033   DEFINE_CLASS_QUERY(LoadVectorGatherMasked)
1034   DEFINE_CLASS_QUERY(StoreVector)
1035   DEFINE_CLASS_QUERY(StoreVectorScatter)
1036   DEFINE_CLASS_QUERY(StoreVectorMasked)
1037   DEFINE_CLASS_QUERY(StoreVectorScatterMasked)
1038   DEFINE_CLASS_QUERY(SaturatingVector)
1039   DEFINE_CLASS_QUERY(ShiftV)
1040   DEFINE_CLASS_QUERY(Unlock)
1041 
1042   #undef DEFINE_CLASS_QUERY
1043 
1044   // duplicate of is_MachSpillCopy()
1045   bool is_SpillCopy () const {
1046     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
1047   }
1048 
1049   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
1050   // The data node which is safe to leave in dead loop during IGVN optimization.
1051   bool is_dead_loop_safe() const;
1052 
1053   // is_Copy() returns copied edge index (0 or 1)
1054   uint is_Copy() const { return (_flags & Flag_is_Copy); }
1055 
1056   virtual bool is_CFG() const { return false; }
1057 
1058   // If this node is control-dependent on a test, can it be
1059   // rerouted to a dominating equivalent test?  This is usually
1060   // true of non-CFG nodes, but can be false for operations which
1061   // depend for their correct sequencing on more than one test.
1062   // (In that case, hoisting to a dominating test may silently
1063   // skip some other important test.)
1064   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
1065 
1066   // When building basic blocks, I need to have a notion of block beginning
1067   // Nodes, next block selector Nodes (block enders), and next block
1068   // projections.  These calls need to work on their machine equivalents.  The
1069   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
1070   bool is_block_start() const {
1071     if ( is_Region() )
1072       return this == (const Node*)in(0);
1073     else
1074       return is_Start();
1075   }
1076 
1077   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
1078   // Goto and Return.  This call also returns the block ending Node.
1079   virtual const Node *is_block_proj() const;
1080 
1081   // The node is a "macro" node which needs to be expanded before matching
1082   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
1083   // The node is expensive: the best control is set during loop opts
1084   bool is_expensive() const { return (_flags & Flag_is_expensive) != 0 && in(0) != nullptr; }
1085   // The node's original edge position is swapped.
1086   bool has_swapped_edges() const { return (_flags & Flag_has_swapped_edges) != 0; }
1087 
1088   bool is_predicated_vector() const { return (_flags & Flag_is_predicated_vector) != 0; }
1089 
1090   bool is_predicated_using_blend() const { return (_flags & Flag_is_predicated_using_blend) != 0; }
1091 
1092   // Used in lcm to mark nodes that have scheduled
1093   bool is_scheduled() const { return (_flags & Flag_is_scheduled) != 0; }
1094 
1095   bool for_post_loop_opts_igvn() const { return (_flags & Flag_for_post_loop_opts_igvn) != 0; }
1096   bool for_merge_stores_igvn() const { return (_flags & Flag_for_merge_stores_igvn) != 0; }
1097 
1098   // Is 'n' possibly a loop entry (i.e. a Parse Predicate projection)?
1099   static bool may_be_loop_entry(Node* n) {
1100     return n != nullptr && n->is_IfProj() && n->in(0)->is_ParsePredicate();
1101   }
1102 
1103 //----------------- Optimization
1104 
1105   // Get the worst-case Type output for this Node.
1106   virtual const class Type *bottom_type() const;
1107 
1108   // If we find a better type for a node, try to record it permanently.
1109   // Return true if this node actually changed.
1110   // Be sure to do the hash_delete game in the "rehash" variant.
1111   void raise_bottom_type(const Type* new_type);
1112 
1113   // Get the address type with which this node uses and/or defs memory,
1114   // or null if none.  The address type is conservatively wide.
1115   // Returns non-null for calls, membars, loads, stores, etc.
1116   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
1117   virtual const class TypePtr *adr_type() const { return nullptr; }
1118 
1119   // Return an existing node which computes the same function as this node.
1120   // The optimistic combined algorithm requires this to return a Node which
1121   // is a small number of steps away (e.g., one of my inputs).
1122   virtual Node* Identity(PhaseGVN* phase);
1123 
1124   // Return the set of values this Node can take on at runtime.
1125   virtual const Type* Value(PhaseGVN* phase) const;
1126 
1127   // Return a node which is more "ideal" than the current node.
1128   // The invariants on this call are subtle.  If in doubt, read the
1129   // treatise in node.cpp above the default implementation AND TEST WITH
1130   // -XX:VerifyIterativeGVN=1
1131   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1132 
1133   // Some nodes have specific Ideal subgraph transformations only if they are
1134   // unique users of specific nodes. Such nodes should be put on IGVN worklist
1135   // for the transformations to happen.
1136   bool has_special_unique_user() const;
1137 
1138   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1139   Node* find_exact_control(Node* ctrl);
1140 
1141   // Results of the dominance analysis.
1142   enum class DomResult {
1143     NotDominate,         // 'this' node does not dominate 'sub'.
1144     Dominate,            // 'this' node dominates or is equal to 'sub'.
1145     EncounteredDeadCode  // Result is undefined due to encountering dead code.
1146   };
1147   // Check if 'this' node dominates or equal to 'sub'.
1148   DomResult dominates(Node* sub, Node_List &nlist);
1149 
1150   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
1151 public:
1152 
1153   // See if there is valid pipeline info
1154   static  const Pipeline *pipeline_class();
1155   virtual const Pipeline *pipeline() const;
1156 
1157   // Compute the latency from the def to this instruction of the ith input node
1158   uint latency(uint i);
1159 
1160   // Hash & compare functions, for pessimistic value numbering
1161 
1162   // If the hash function returns the special sentinel value NO_HASH,
1163   // the node is guaranteed never to compare equal to any other node.
1164   // If we accidentally generate a hash with value NO_HASH the node
1165   // won't go into the table and we'll lose a little optimization.
1166   static const uint NO_HASH = 0;
1167   virtual uint hash() const;
1168   virtual bool cmp( const Node &n ) const;
1169 
1170   // Operation appears to be iteratively computed (such as an induction variable)
1171   // It is possible for this operation to return false for a loop-varying
1172   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1173   bool is_iteratively_computed();
1174 
1175   // Determine if a node is a counted loop induction variable.
1176   // NOTE: The method is defined in "loopnode.cpp".
1177   bool is_cloop_ind_var() const;
1178 
1179   // Return a node with opcode "opc" and same inputs as "this" if one can
1180   // be found; Otherwise return null;
1181   Node* find_similar(int opc);
1182 
1183   // Return the unique control out if only one. Null if none or more than one.
1184   Node* unique_ctrl_out_or_null() const;
1185   // Return the unique control out. Asserts if none or more than one control out.
1186   Node* unique_ctrl_out() const;
1187 
1188   // Set control or add control as precedence edge
1189   void ensure_control_or_add_prec(Node* c);
1190   void add_prec_from(Node* n);
1191 
1192   // Visit boundary uses of the node and apply a callback function for each.
1193   // Recursively traverse uses, stopping and applying the callback when
1194   // reaching a boundary node, defined by is_boundary. Note: the function
1195   // definition appears after the complete type definition of Node_List.
1196   template <typename Callback, typename Check>
1197   void visit_uses(Callback callback, Check is_boundary) const;
1198 
1199   // Returns a clone of the current node that's pinned (if the current node is not) for nodes found in array accesses
1200   // (Load and range check CastII nodes).
1201   // This is used when an array access is made dependent on 2 or more range checks (range check smearing or Loop Predication).
1202   virtual Node* pin_array_access_node() const {
1203     return nullptr;
1204   }
1205 
1206   //----------------- Code Generation
1207 
1208   // Ideal register class for Matching.  Zero means unmatched instruction
1209   // (these are cloned instead of converted to machine nodes).
1210   virtual uint ideal_reg() const;
1211 
1212   static const uint NotAMachineReg;   // must be > max. machine register
1213 
1214   // Do we Match on this edge index or not?  Generally false for Control
1215   // and true for everything else.  Weird for calls & returns.
1216   virtual uint match_edge(uint idx) const;
1217 
1218   // Register class output is returned in
1219   virtual const RegMask &out_RegMask() const;
1220   // Register class input is expected in
1221   virtual const RegMask &in_RegMask(uint) const;
1222   // Should we clone rather than spill this instruction?
1223   bool rematerialize() const;
1224 
1225   // Return JVM State Object if this Node carries debug info, or null otherwise
1226   virtual JVMState* jvms() const;
1227 
1228   // Print as assembly
1229   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
1230   // Emit bytes using C2_MacroAssembler
1231   virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const;
1232   // Size of instruction in bytes
1233   virtual uint size(PhaseRegAlloc *ra_) const;
1234 
1235   // Convenience function to extract an integer constant from a node.
1236   // If it is not an integer constant (either Con, CastII, or Mach),
1237   // return value_if_unknown.
1238   jint find_int_con(jint value_if_unknown) const {
1239     const TypeInt* t = find_int_type();
1240     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1241   }
1242   // Return the constant, knowing it is an integer constant already
1243   jint get_int() const {
1244     const TypeInt* t = find_int_type();
1245     guarantee(t != nullptr, "must be con");
1246     return t->get_con();
1247   }
1248   // Here's where the work is done.  Can produce non-constant int types too.
1249   const TypeInt* find_int_type() const;
1250   const TypeInteger* find_integer_type(BasicType bt) const;
1251 
1252   // Same thing for long (and intptr_t, via type.hpp):
1253   jlong get_long() const {
1254     const TypeLong* t = find_long_type();
1255     guarantee(t != nullptr, "must be con");
1256     return t->get_con();
1257   }
1258   jlong find_long_con(jint value_if_unknown) const {
1259     const TypeLong* t = find_long_type();
1260     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1261   }
1262   const TypeLong* find_long_type() const;
1263 
1264   jlong get_integer_as_long(BasicType bt) const {
1265     const TypeInteger* t = find_integer_type(bt);
1266     guarantee(t != nullptr && t->is_con(), "must be con");
1267     return t->get_con_as_long(bt);
1268   }
1269   jlong find_integer_as_long(BasicType bt, jlong value_if_unknown) const {
1270     const TypeInteger* t = find_integer_type(bt);
1271     if (t == nullptr || !t->is_con())  return value_if_unknown;
1272     return t->get_con_as_long(bt);
1273   }
1274   const TypePtr* get_ptr_type() const;
1275 
1276   // These guys are called by code generated by ADLC:
1277   intptr_t get_ptr() const;
1278   intptr_t get_narrowcon() const;
1279   jdouble getd() const;
1280   jfloat getf() const;
1281   jshort geth() const;
1282 
1283   // Nodes which are pinned into basic blocks
1284   virtual bool pinned() const { return false; }
1285 
1286   // Nodes which use memory without consuming it, hence need antidependences
1287   // More specifically, needs_anti_dependence_check returns true iff the node
1288   // (a) does a load, and (b) does not perform a store (except perhaps to a
1289   // stack slot or some other unaliased location).
1290   bool needs_anti_dependence_check() const;
1291 
1292   // Return which operand this instruction may cisc-spill. In other words,
1293   // return operand position that can convert from reg to memory access
1294   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
1295   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
1296 
1297   // Whether this is a memory-writing machine node.
1298   bool is_memory_writer() const { return is_Mach() && bottom_type()->has_memory(); }
1299 
1300   // Whether this is a memory phi node
1301   bool is_memory_phi() const { return is_Phi() && bottom_type() == Type::MEMORY; }
1302 
1303   bool is_div_or_mod(BasicType bt) const;
1304 
1305   bool is_data_proj_of_pure_function(const Node* maybe_pure_function) const;
1306 
1307 //----------------- Printing, etc
1308 #ifndef PRODUCT
1309  public:
1310   Node* find(int idx, bool only_ctrl = false); // Search the graph for the given idx.
1311   Node* find_ctrl(int idx); // Search control ancestors for the given idx.
1312   void dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st, const frame* fr = nullptr) const;
1313   void dump_bfs(const int max_distance, Node* target, const char* options) const; // directly to tty
1314   void dump_bfs(const int max_distance) const; // dump_bfs(max_distance, nullptr, nullptr)
1315   void dump_bfs(const int max_distance, Node* target, const char* options, void* sp, void* fp, void* pc) const;
1316   class DumpConfig {
1317    public:
1318     // overridden to implement coloring of node idx
1319     virtual void pre_dump(outputStream *st, const Node* n) = 0;
1320     virtual void post_dump(outputStream *st) = 0;
1321   };
1322   void dump_idx(bool align = false, outputStream* st = tty, DumpConfig* dc = nullptr) const;
1323   void dump_name(outputStream* st = tty, DumpConfig* dc = nullptr) const;
1324   void dump() const; // print node with newline
1325   void dump(const char* suffix, bool mark = false, outputStream* st = tty, DumpConfig* dc = nullptr) const; // Print this node.
1326   void dump(int depth) const;        // Print this node, recursively to depth d
1327   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
1328   void dump_comp() const;            // Print this node in compact representation.
1329   // Print this node in compact representation.
1330   void dump_comp(const char* suffix, outputStream *st = tty) const;
1331  private:
1332   virtual void dump_req(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print required-edge info
1333   virtual void dump_prec(outputStream* st = tty, DumpConfig* dc = nullptr) const;   // Print precedence-edge info
1334   virtual void dump_out(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print the output edge info
1335  public:
1336   virtual void dump_spec(outputStream *st) const {};      // Print per-node info
1337   // Print compact per-node info
1338   virtual void dump_compact_spec(outputStream *st) const { dump_spec(st); }
1339 
1340   static void verify(int verify_depth, VectorSet& visited, Node_List& worklist);
1341 
1342   // This call defines a class-unique string used to identify class instances
1343   virtual const char *Name() const;
1344 
1345   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1346   static bool in_dump() { return Compile::current()->_in_dump_cnt > 0; } // check if we are in a dump call
1347 #endif
1348 #ifdef ASSERT
1349   void verify_construction();
1350   bool verify_jvms(const JVMState* jvms) const;
1351 
1352   Node* _debug_orig;                   // Original version of this, if any.
1353   Node*  debug_orig() const            { return _debug_orig; }
1354   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1355   void   dump_orig(outputStream *st, bool print_key = true) const;
1356 
1357   uint64_t _debug_idx;                 // Unique value assigned to every node.
1358   uint64_t debug_idx() const           { return _debug_idx; }
1359   void set_debug_idx(uint64_t debug_idx) { _debug_idx = debug_idx; }
1360 
1361   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1362   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1363   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1364 
1365   static void init_NodeProperty();
1366 
1367   #if OPTO_DU_ITERATOR_ASSERT
1368   const Node* _last_del;               // The last deleted node.
1369   uint        _del_tick;               // Bumped when a deletion happens..
1370   #endif
1371 #endif
1372 };
1373 
1374 inline bool not_a_node(const Node* n) {
1375   if (n == nullptr)                return true;
1376   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
1377   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
1378   return false;
1379 }
1380 
1381 //-----------------------------------------------------------------------------
1382 // Iterators over DU info, and associated Node functions.
1383 
1384 #if OPTO_DU_ITERATOR_ASSERT
1385 
1386 // Common code for assertion checking on DU iterators.
1387 class DUIterator_Common {
1388 #ifdef ASSERT
1389  protected:
1390   bool         _vdui;               // cached value of VerifyDUIterators
1391   const Node*  _node;               // the node containing the _out array
1392   uint         _outcnt;             // cached node->_outcnt
1393   uint         _del_tick;           // cached node->_del_tick
1394   Node*        _last;               // last value produced by the iterator
1395 
1396   void sample(const Node* node);    // used by c'tor to set up for verifies
1397   void verify(const Node* node, bool at_end_ok = false);
1398   void verify_resync();
1399   void reset(const DUIterator_Common& that);
1400 
1401 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1402   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1403 #else
1404   #define I_VDUI_ONLY(i,x) { }
1405 #endif //ASSERT
1406 };
1407 
1408 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1409 
1410 // Default DU iterator.  Allows appends onto the out array.
1411 // Allows deletion from the out array only at the current point.
1412 // Usage:
1413 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1414 //    Node* y = x->out(i);
1415 //    ...
1416 //  }
1417 // Compiles in product mode to a unsigned integer index, which indexes
1418 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1419 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1420 // before continuing the loop.  You must delete only the last-produced
1421 // edge.  You must delete only a single copy of the last-produced edge,
1422 // or else you must delete all copies at once (the first time the edge
1423 // is produced by the iterator).
1424 class DUIterator : public DUIterator_Common {
1425   friend class Node;
1426 
1427   // This is the index which provides the product-mode behavior.
1428   // Whatever the product-mode version of the system does to the
1429   // DUI index is done to this index.  All other fields in
1430   // this class are used only for assertion checking.
1431   uint         _idx;
1432 
1433   #ifdef ASSERT
1434   uint         _refresh_tick;    // Records the refresh activity.
1435 
1436   void sample(const Node* node); // Initialize _refresh_tick etc.
1437   void verify(const Node* node, bool at_end_ok = false);
1438   void verify_increment();       // Verify an increment operation.
1439   void verify_resync();          // Verify that we can back up over a deletion.
1440   void verify_finish();          // Verify that the loop terminated properly.
1441   void refresh();                // Resample verification info.
1442   void reset(const DUIterator& that);  // Resample after assignment.
1443   #endif
1444 
1445   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1446     { _idx = 0;                         DEBUG_ONLY(sample(node)); }
1447 
1448  public:
1449   // initialize to garbage; clear _vdui to disable asserts
1450   DUIterator()
1451     { /*initialize to garbage*/         DEBUG_ONLY(_vdui = false); }
1452 
1453   DUIterator(const DUIterator& that)
1454     { _idx = that._idx;                 DEBUG_ONLY(_vdui = false; reset(that)); }
1455 
1456   void operator++(int dummy_to_specify_postfix_op)
1457     { _idx++;                           VDUI_ONLY(verify_increment()); }
1458 
1459   void operator--()
1460     { VDUI_ONLY(verify_resync());       --_idx; }
1461 
1462   ~DUIterator()
1463     { VDUI_ONLY(verify_finish()); }
1464 
1465   void operator=(const DUIterator& that)
1466     { _idx = that._idx;                 DEBUG_ONLY(reset(that)); }
1467 };
1468 
1469 DUIterator Node::outs() const
1470   { return DUIterator(this, 0); }
1471 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1472   { I_VDUI_ONLY(i, i.refresh());        return i; }
1473 bool Node::has_out(DUIterator& i) const
1474   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1475 Node*    Node::out(DUIterator& i) const
1476   { I_VDUI_ONLY(i, i.verify(this));     return DEBUG_ONLY(i._last=) _out[i._idx]; }
1477 
1478 
1479 // Faster DU iterator.  Disallows insertions into the out array.
1480 // Allows deletion from the out array only at the current point.
1481 // Usage:
1482 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1483 //    Node* y = x->fast_out(i);
1484 //    ...
1485 //  }
1486 // Compiles in product mode to raw Node** pointer arithmetic, with
1487 // no reloading of pointers from the original node x.  If you delete,
1488 // you must perform "--i; --imax" just before continuing the loop.
1489 // If you delete multiple copies of the same edge, you must decrement
1490 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1491 class DUIterator_Fast : public DUIterator_Common {
1492   friend class Node;
1493   friend class DUIterator_Last;
1494 
1495   // This is the pointer which provides the product-mode behavior.
1496   // Whatever the product-mode version of the system does to the
1497   // DUI pointer is done to this pointer.  All other fields in
1498   // this class are used only for assertion checking.
1499   Node**       _outp;
1500 
1501   #ifdef ASSERT
1502   void verify(const Node* node, bool at_end_ok = false);
1503   void verify_limit();
1504   void verify_resync();
1505   void verify_relimit(uint n);
1506   void reset(const DUIterator_Fast& that);
1507   #endif
1508 
1509   // Note:  offset must be signed, since -1 is sometimes passed
1510   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1511     { _outp = node->_out + offset;      DEBUG_ONLY(sample(node)); }
1512 
1513  public:
1514   // initialize to garbage; clear _vdui to disable asserts
1515   DUIterator_Fast()
1516     { /*initialize to garbage*/         DEBUG_ONLY(_vdui = false); }
1517 
1518   DUIterator_Fast(const DUIterator_Fast& that)
1519     { _outp = that._outp;               DEBUG_ONLY(_vdui = false; reset(that)); }
1520 
1521   void operator++(int dummy_to_specify_postfix_op)
1522     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1523 
1524   void operator--()
1525     { VDUI_ONLY(verify_resync());       --_outp; }
1526 
1527   void operator-=(uint n)   // applied to the limit only
1528     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1529 
1530   bool operator<(DUIterator_Fast& limit) {
1531     I_VDUI_ONLY(*this, this->verify(_node, true));
1532     I_VDUI_ONLY(limit, limit.verify_limit());
1533     return _outp < limit._outp;
1534   }
1535 
1536   void operator=(const DUIterator_Fast& that)
1537     { _outp = that._outp;               DEBUG_ONLY(reset(that)); }
1538 };
1539 
1540 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1541   // Assign a limit pointer to the reference argument:
1542   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1543   // Return the base pointer:
1544   return DUIterator_Fast(this, 0);
1545 }
1546 Node* Node::fast_out(DUIterator_Fast& i) const {
1547   I_VDUI_ONLY(i, i.verify(this));
1548   return DEBUG_ONLY(i._last=) *i._outp;
1549 }
1550 
1551 
1552 // Faster DU iterator.  Requires each successive edge to be removed.
1553 // Does not allow insertion of any edges.
1554 // Usage:
1555 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1556 //    Node* y = x->last_out(i);
1557 //    ...
1558 //  }
1559 // Compiles in product mode to raw Node** pointer arithmetic, with
1560 // no reloading of pointers from the original node x.
1561 class DUIterator_Last : private DUIterator_Fast {
1562   friend class Node;
1563 
1564   #ifdef ASSERT
1565   void verify(const Node* node, bool at_end_ok = false);
1566   void verify_limit();
1567   void verify_step(uint num_edges);
1568   #endif
1569 
1570   // Note:  offset must be signed, since -1 is sometimes passed
1571   DUIterator_Last(const Node* node, ptrdiff_t offset)
1572     : DUIterator_Fast(node, offset) { }
1573 
1574   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1575   void operator<(int)                              {} // do not use
1576 
1577  public:
1578   DUIterator_Last() { }
1579   // initialize to garbage
1580 
1581   DUIterator_Last(const DUIterator_Last& that) = default;
1582 
1583   void operator--()
1584     { _outp--;              VDUI_ONLY(verify_step(1));  }
1585 
1586   void operator-=(uint n)
1587     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1588 
1589   bool operator>=(DUIterator_Last& limit) {
1590     I_VDUI_ONLY(*this, this->verify(_node, true));
1591     I_VDUI_ONLY(limit, limit.verify_limit());
1592     return _outp >= limit._outp;
1593   }
1594 
1595   DUIterator_Last& operator=(const DUIterator_Last& that) = default;
1596 };
1597 
1598 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1599   // Assign a limit pointer to the reference argument:
1600   imin = DUIterator_Last(this, 0);
1601   // Return the initial pointer:
1602   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1603 }
1604 Node* Node::last_out(DUIterator_Last& i) const {
1605   I_VDUI_ONLY(i, i.verify(this));
1606   return DEBUG_ONLY(i._last=) *i._outp;
1607 }
1608 
1609 #endif //OPTO_DU_ITERATOR_ASSERT
1610 
1611 #undef I_VDUI_ONLY
1612 #undef VDUI_ONLY
1613 
1614 // An Iterator that truly follows the iterator pattern.  Doesn't
1615 // support deletion but could be made to.
1616 //
1617 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1618 //     Node* m = i.get();
1619 //
1620 class SimpleDUIterator : public StackObj {
1621  private:
1622   Node* node;
1623   DUIterator_Fast imax;
1624   DUIterator_Fast i;
1625  public:
1626   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1627   bool has_next() { return i < imax; }
1628   void next() { i++; }
1629   Node* get() { return node->fast_out(i); }
1630 };
1631 
1632 
1633 //-----------------------------------------------------------------------------
1634 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1635 // Abstractly provides an infinite array of Node*'s, initialized to null.
1636 // Note that the constructor just zeros things, and since I use Arena
1637 // allocation I do not need a destructor to reclaim storage.
1638 class Node_Array : public AnyObj {
1639 protected:
1640   Arena* _a;                    // Arena to allocate in
1641   uint   _max;
1642   Node** _nodes;
1643   ReallocMark _nesting;         // Safety checks for arena reallocation
1644 
1645   // Grow array to required capacity
1646   void maybe_grow(uint i) {
1647     _nesting.check(_a); // Check if a potential reallocation in the arena is safe
1648     if (i >= _max) {
1649       grow(i);
1650     }
1651   }
1652   void grow(uint i);
1653 
1654 public:
1655   Node_Array(Arena* a, uint max = OptoNodeListSize) : _a(a), _max(max) {
1656     _nodes = NEW_ARENA_ARRAY(a, Node*, max);
1657     clear();
1658   }
1659   Node_Array() : Node_Array(Thread::current()->resource_area()) {}
1660 
1661   NONCOPYABLE(Node_Array);
1662   Node_Array& operator=(Node_Array&&) = delete;
1663   // Allow move constructor for && (eg. capture return of function)
1664   Node_Array(Node_Array&&) = default;
1665 
1666   Node *operator[] ( uint i ) const // Lookup, or null for not mapped
1667   { return (i<_max) ? _nodes[i] : (Node*)nullptr; }
1668   Node* at(uint i) const { assert(i<_max,"oob"); return _nodes[i]; }
1669   Node** adr() { return _nodes; }
1670   // Extend the mapping: index i maps to Node *n.
1671   void map( uint i, Node *n ) { maybe_grow(i); _nodes[i] = n; }
1672   void insert( uint i, Node *n );
1673   void remove( uint i );        // Remove, preserving order
1674   // Clear all entries in _nodes to null but keep storage
1675   void clear() {
1676     Copy::zero_to_bytes(_nodes, _max * sizeof(Node*));
1677   }
1678 
1679   uint max() const { return _max; }
1680   void dump() const;
1681 };
1682 
1683 class Node_List : public Node_Array {
1684   uint _cnt;
1685 public:
1686   Node_List(uint max = OptoNodeListSize) : Node_Array(Thread::current()->resource_area(), max), _cnt(0) {}
1687   Node_List(Arena *a, uint max = OptoNodeListSize) : Node_Array(a, max), _cnt(0) {}
1688 
1689   NONCOPYABLE(Node_List);
1690   Node_List& operator=(Node_List&&) = delete;
1691   // Allow move constructor for && (eg. capture return of function)
1692   Node_List(Node_List&&) = default;
1693 
1694   bool contains(const Node* n) const {
1695     for (uint e = 0; e < size(); e++) {
1696       if (at(e) == n) return true;
1697     }
1698     return false;
1699   }
1700   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1701   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1702   void push( Node *b ) { map(_cnt++,b); }
1703   void yank( Node *n );         // Find and remove
1704   Node *pop() { return _nodes[--_cnt]; }
1705   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1706   void copy(const Node_List& from) {
1707     if (from._max > _max) {
1708       grow(from._max);
1709     }
1710     _cnt = from._cnt;
1711     Copy::conjoint_words_to_higher((HeapWord*)&from._nodes[0], (HeapWord*)&_nodes[0], from._max * sizeof(Node*));
1712   }
1713 
1714   uint size() const { return _cnt; }
1715   void dump() const;
1716   void dump_simple() const;
1717 };
1718 
1719 // Definition must appear after complete type definition of Node_List
1720 template <typename Callback, typename Check>
1721 void Node::visit_uses(Callback callback, Check is_boundary) const {
1722   ResourceMark rm;
1723   VectorSet visited;
1724   Node_List worklist;
1725 
1726   // The initial worklist consists of the direct uses
1727   for (DUIterator_Fast kmax, k = fast_outs(kmax); k < kmax; k++) {
1728     Node* out = fast_out(k);
1729     if (!visited.test_set(out->_idx)) { worklist.push(out); }
1730   }
1731 
1732   while (worklist.size() > 0) {
1733     Node* use = worklist.pop();
1734     // Apply callback on boundary nodes
1735     if (is_boundary(use)) {
1736       callback(use);
1737     } else {
1738       // Not a boundary node, continue search
1739       for (DUIterator_Fast kmax, k = use->fast_outs(kmax); k < kmax; k++) {
1740         Node* out = use->fast_out(k);
1741         if (!visited.test_set(out->_idx)) { worklist.push(out); }
1742       }
1743     }
1744   }
1745 }
1746 
1747 
1748 //------------------------------Unique_Node_List-------------------------------
1749 class Unique_Node_List : public Node_List {
1750   VectorSet _in_worklist;
1751   uint _clock_index;            // Index in list where to pop from next
1752 public:
1753   Unique_Node_List() : Node_List(), _clock_index(0) {}
1754   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1755 
1756   NONCOPYABLE(Unique_Node_List);
1757   Unique_Node_List& operator=(Unique_Node_List&&) = delete;
1758   // Allow move constructor for && (eg. capture return of function)
1759   Unique_Node_List(Unique_Node_List&&) = default;
1760 
1761   void remove( Node *n );
1762   bool member(const Node* n) const { return _in_worklist.test(n->_idx) != 0; }
1763   VectorSet& member_set(){ return _in_worklist; }
1764 
1765   void push(Node* b) {
1766     if( !_in_worklist.test_set(b->_idx) )
1767       Node_List::push(b);
1768   }
1769   void push_non_cfg_inputs_of(const Node* node) {
1770     for (uint i = 1; i < node->req(); i++) {
1771       Node* input = node->in(i);
1772       if (input != nullptr && !input->is_CFG()) {
1773         push(input);
1774       }
1775     }
1776   }
1777 
1778   void push_outputs_of(const Node* node) {
1779     for (DUIterator_Fast imax, i = node->fast_outs(imax); i < imax; i++) {
1780       Node* output = node->fast_out(i);
1781       push(output);
1782     }
1783   }
1784 
1785   Node *pop() {
1786     if( _clock_index >= size() ) _clock_index = 0;
1787     Node *b = at(_clock_index);
1788     map( _clock_index, Node_List::pop());
1789     if (size() != 0) _clock_index++; // Always start from 0
1790     _in_worklist.remove(b->_idx);
1791     return b;
1792   }
1793   Node *remove(uint i) {
1794     Node *b = Node_List::at(i);
1795     _in_worklist.remove(b->_idx);
1796     map(i,Node_List::pop());
1797     return b;
1798   }
1799   void yank(Node *n) {
1800     _in_worklist.remove(n->_idx);
1801     Node_List::yank(n);
1802   }
1803   void  clear() {
1804     _in_worklist.clear();        // Discards storage but grows automatically
1805     Node_List::clear();
1806     _clock_index = 0;
1807   }
1808   void ensure_empty() {
1809     assert(size() == 0, "must be empty");
1810     clear(); // just in case
1811   }
1812 
1813   // Used after parsing to remove useless nodes before Iterative GVN
1814   void remove_useless_nodes(VectorSet& useful);
1815 
1816   // If the idx of the Nodes change, we must recompute the VectorSet
1817   void recompute_idx_set() {
1818     _in_worklist.clear();
1819     for (uint i = 0; i < size(); i++) {
1820       Node* n = at(i);
1821       _in_worklist.set(n->_idx);
1822     }
1823   }
1824 
1825 #ifdef ASSERT
1826   bool is_subset_of(Unique_Node_List& other) {
1827     for (uint i = 0; i < size(); i++) {
1828       Node* n = at(i);
1829       if (!other.member(n)) {
1830         return false;
1831       }
1832     }
1833     return true;
1834   }
1835 #endif
1836 
1837   bool contains(const Node* n) const {
1838     fatal("use faster member() instead");
1839     return false;
1840   }
1841 
1842 #ifndef PRODUCT
1843   void print_set() const { _in_worklist.print(); }
1844 #endif
1845 };
1846 
1847 // Unique_Mixed_Node_List
1848 // unique: nodes are added only once
1849 // mixed: allow new and old nodes
1850 class Unique_Mixed_Node_List : public ResourceObj {
1851 public:
1852   Unique_Mixed_Node_List() : _visited_set(cmpkey, hashkey) {}
1853 
1854   void add(Node* node) {
1855     if (not_a_node(node)) {
1856       return; // Gracefully handle null, -1, 0xabababab, etc.
1857     }
1858     if (_visited_set[node] == nullptr) {
1859       _visited_set.Insert(node, node);
1860       _worklist.push(node);
1861     }
1862   }
1863 
1864   Node* operator[] (uint i) const {
1865     return _worklist[i];
1866   }
1867 
1868   size_t size() {
1869     return _worklist.size();
1870   }
1871 
1872 private:
1873   Dict _visited_set;
1874   Node_List _worklist;
1875 };
1876 
1877 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1878 inline void Compile::record_for_igvn(Node* n) {
1879   _igvn_worklist->push(n);
1880 }
1881 
1882 // Inline definition of Compile::remove_for_igvn must be deferred to this point.
1883 inline void Compile::remove_for_igvn(Node* n) {
1884   _igvn_worklist->remove(n);
1885 }
1886 
1887 //------------------------------Node_Stack-------------------------------------
1888 class Node_Stack {
1889 protected:
1890   struct INode {
1891     Node *node; // Processed node
1892     uint  indx; // Index of next node's child
1893   };
1894   INode *_inode_top; // tos, stack grows up
1895   INode *_inode_max; // End of _inodes == _inodes + _max
1896   INode *_inodes;    // Array storage for the stack
1897   Arena *_a;         // Arena to allocate in
1898   ReallocMark _nesting; // Safety checks for arena reallocation
1899 
1900   void maybe_grow() {
1901     _nesting.check(_a); // Check if a potential reallocation in the arena is safe
1902     if (_inode_top >= _inode_max) {
1903       grow();
1904     }
1905   }
1906   void grow();
1907 
1908 public:
1909   Node_Stack(int size) {
1910     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1911     _a = Thread::current()->resource_area();
1912     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1913     _inode_max = _inodes + max;
1914     _inode_top = _inodes - 1; // stack is empty
1915   }
1916 
1917   Node_Stack(Arena *a, int size) : _a(a) {
1918     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1919     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1920     _inode_max = _inodes + max;
1921     _inode_top = _inodes - 1; // stack is empty
1922   }
1923 
1924   void pop() {
1925     assert(_inode_top >= _inodes, "node stack underflow");
1926     --_inode_top;
1927   }
1928   void push(Node *n, uint i) {
1929     ++_inode_top;
1930     maybe_grow();
1931     INode *top = _inode_top; // optimization
1932     top->node = n;
1933     top->indx = i;
1934   }
1935   Node *node() const {
1936     return _inode_top->node;
1937   }
1938   Node* node_at(uint i) const {
1939     assert(_inodes + i <= _inode_top, "in range");
1940     return _inodes[i].node;
1941   }
1942   uint index() const {
1943     return _inode_top->indx;
1944   }
1945   uint index_at(uint i) const {
1946     assert(_inodes + i <= _inode_top, "in range");
1947     return _inodes[i].indx;
1948   }
1949   void set_node(Node *n) {
1950     _inode_top->node = n;
1951   }
1952   void set_index(uint i) {
1953     _inode_top->indx = i;
1954   }
1955   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1956   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1957   bool is_nonempty() const { return (_inode_top >= _inodes); }
1958   bool is_empty() const { return (_inode_top < _inodes); }
1959   void clear() { _inode_top = _inodes - 1; } // retain storage
1960 
1961   // Node_Stack is used to map nodes.
1962   Node* find(uint idx) const;
1963 
1964   NONCOPYABLE(Node_Stack);
1965 };
1966 
1967 
1968 //-----------------------------Node_Notes--------------------------------------
1969 // Debugging or profiling annotations loosely and sparsely associated
1970 // with some nodes.  See Compile::node_notes_at for the accessor.
1971 class Node_Notes {
1972   JVMState* _jvms;
1973 
1974 public:
1975   Node_Notes(JVMState* jvms = nullptr) {
1976     _jvms = jvms;
1977   }
1978 
1979   JVMState* jvms()            { return _jvms; }
1980   void  set_jvms(JVMState* x) {        _jvms = x; }
1981 
1982   // True if there is nothing here.
1983   bool is_clear() {
1984     return (_jvms == nullptr);
1985   }
1986 
1987   // Make there be nothing here.
1988   void clear() {
1989     _jvms = nullptr;
1990   }
1991 
1992   // Make a new, clean node notes.
1993   static Node_Notes* make(Compile* C) {
1994     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
1995     nn->clear();
1996     return nn;
1997   }
1998 
1999   Node_Notes* clone(Compile* C) {
2000     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
2001     (*nn) = (*this);
2002     return nn;
2003   }
2004 
2005   // Absorb any information from source.
2006   bool update_from(Node_Notes* source) {
2007     bool changed = false;
2008     if (source != nullptr) {
2009       if (source->jvms() != nullptr) {
2010         set_jvms(source->jvms());
2011         changed = true;
2012       }
2013     }
2014     return changed;
2015   }
2016 };
2017 
2018 // Inlined accessors for Compile::node_nodes that require the preceding class:
2019 inline Node_Notes*
2020 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
2021                            int idx, bool can_grow) {
2022   assert(idx >= 0, "oob");
2023   int block_idx = (idx >> _log2_node_notes_block_size);
2024   int grow_by = (block_idx - (arr == nullptr? 0: arr->length()));
2025   if (grow_by >= 0) {
2026     if (!can_grow) return nullptr;
2027     grow_node_notes(arr, grow_by + 1);
2028   }
2029   if (arr == nullptr) return nullptr;
2030   // (Every element of arr is a sub-array of length _node_notes_block_size.)
2031   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
2032 }
2033 
2034 inline Node_Notes* Compile::node_notes_at(int idx) {
2035   return locate_node_notes(_node_note_array, idx, false);
2036 }
2037 
2038 inline bool
2039 Compile::set_node_notes_at(int idx, Node_Notes* value) {
2040   if (value == nullptr || value->is_clear())
2041     return false;  // nothing to write => write nothing
2042   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
2043   assert(loc != nullptr, "");
2044   return loc->update_from(value);
2045 }
2046 
2047 
2048 //------------------------------TypeNode---------------------------------------
2049 // Node with a Type constant.
2050 class TypeNode : public Node {
2051 protected:
2052   virtual uint hash() const;    // Check the type
2053   virtual bool cmp( const Node &n ) const;
2054   virtual uint size_of() const; // Size is bigger
2055   const Type* const _type;
2056 public:
2057   void set_type(const Type* t) {
2058     assert(t != nullptr, "sanity");
2059     DEBUG_ONLY(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
2060     *(const Type**)&_type = t;   // cast away const-ness
2061     // If this node is in the hash table, make sure it doesn't need a rehash.
2062     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
2063   }
2064   const Type* type() const { assert(_type != nullptr, "sanity"); return _type; };
2065   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
2066     init_class_id(Class_Type);
2067   }
2068   virtual const Type* Value(PhaseGVN* phase) const;
2069   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
2070   virtual const Type *bottom_type() const;
2071   virtual       uint  ideal_reg() const;
2072 
2073   void make_path_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, Node* ctrl_use, uint j, const char* phase_str);
2074 #ifndef PRODUCT
2075   virtual void dump_spec(outputStream *st) const;
2076   virtual void dump_compact_spec(outputStream *st) const;
2077 #endif
2078   void make_paths_from_here_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, const char* phase_str);
2079   void create_halt_path(PhaseIterGVN* igvn, Node* c, PhaseIdealLoop* loop, const char* phase_str) const;
2080 };
2081 
2082 #include "opto/opcodes.hpp"
2083 
2084 #define Op_IL(op) \
2085   inline int Op_ ## op(BasicType bt) { \
2086   assert(bt == T_INT || bt == T_LONG, "only for int or longs"); \
2087   if (bt == T_INT) { \
2088     return Op_## op ## I; \
2089   } \
2090   return Op_## op ## L; \
2091 }
2092 
2093 Op_IL(Add)
2094 Op_IL(And)
2095 Op_IL(Sub)
2096 Op_IL(Mul)
2097 Op_IL(URShift)
2098 Op_IL(LShift)
2099 Op_IL(RShift)
2100 Op_IL(Xor)
2101 Op_IL(Cmp)
2102 Op_IL(Div)
2103 Op_IL(Mod)
2104 Op_IL(UDiv)
2105 Op_IL(UMod)
2106 
2107 inline int Op_ConIL(BasicType bt) {
2108   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2109   if (bt == T_INT) {
2110     return Op_ConI;
2111   }
2112   return Op_ConL;
2113 }
2114 
2115 inline int Op_Cmp_unsigned(BasicType bt) {
2116   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2117   if (bt == T_INT) {
2118     return Op_CmpU;
2119   }
2120   return Op_CmpUL;
2121 }
2122 
2123 inline int Op_Cast(BasicType bt) {
2124   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2125   if (bt == T_INT) {
2126     return Op_CastII;
2127   }
2128   return Op_CastLL;
2129 }
2130 
2131 inline int Op_DivIL(BasicType bt, bool is_unsigned) {
2132   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2133   if (bt == T_INT) {
2134     if (is_unsigned) {
2135       return Op_UDivI;
2136     } else {
2137       return Op_DivI;
2138     }
2139   }
2140   if (is_unsigned) {
2141     return Op_UDivL;
2142   } else {
2143     return Op_DivL;
2144   }
2145 }
2146 
2147 inline int Op_DivModIL(BasicType bt, bool is_unsigned) {
2148   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2149   if (bt == T_INT) {
2150     if (is_unsigned) {
2151       return Op_UDivModI;
2152     } else {
2153       return Op_DivModI;
2154     }
2155   }
2156   if (is_unsigned) {
2157     return Op_UDivModL;
2158   } else {
2159     return Op_DivModL;
2160   }
2161 }
2162 
2163 // Interface to define actions that should be taken when running DataNodeBFS. Each use can extend this class to specify
2164 // a customized BFS.
2165 class BFSActions : public StackObj {
2166  public:
2167   // Should a node's inputs further be visited in the BFS traversal? By default, we visit all data inputs. Override this
2168   // method to provide a custom filter.
2169   virtual bool should_visit(Node* node) const {
2170     // By default, visit all inputs.
2171     return true;
2172   };
2173 
2174   // Is the visited node a target node that we are looking for in the BFS traversal? We do not visit its inputs further
2175   // but the BFS will continue to visit all unvisited nodes in the queue.
2176   virtual bool is_target_node(Node* node) const = 0;
2177 
2178   // Defines an action that should be taken when we visit a target node in the BFS traversal.
2179   virtual void target_node_action(Node* target_node) = 0;
2180 };
2181 
2182 // Class to perform a BFS traversal on the data nodes from a given start node. The provided BFSActions guide which
2183 // data node's inputs should be further visited, which data nodes are target nodes and what to do with the target nodes.
2184 class DataNodeBFS : public StackObj {
2185   BFSActions& _bfs_actions;
2186 
2187  public:
2188   explicit DataNodeBFS(BFSActions& bfs_action) : _bfs_actions(bfs_action) {}
2189 
2190   // Run the BFS starting from 'start_node' and apply the actions provided to this class.
2191   void run(Node* start_node) {
2192     ResourceMark rm;
2193     Unique_Node_List _nodes_to_visit;
2194     _nodes_to_visit.push(start_node);
2195     for (uint i = 0; i < _nodes_to_visit.size(); i++) {
2196       Node* next = _nodes_to_visit[i];
2197       for (uint j = 1; j < next->req(); j++) {
2198         Node* input = next->in(j);
2199         if (_bfs_actions.is_target_node(input)) {
2200           assert(_bfs_actions.should_visit(input), "must also pass node filter");
2201           _bfs_actions.target_node_action(input);
2202         } else if (_bfs_actions.should_visit(input)) {
2203           _nodes_to_visit.push(input);
2204         }
2205       }
2206     }
2207   }
2208 };
2209 
2210 #endif // SHARE_OPTO_NODE_HPP