1 /*
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   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).
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  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
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  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 MinMaxNode;
 134 class MoveNode;
 135 class MulNode;
 136 class MultiNode;
 137 class MultiBranchNode;
 138 class NarrowMemProjNode;
 139 class NegNode;
 140 class NegVNode;
 141 class NeverBranchNode;
 142 class Opaque1Node;
 143 class OpaqueLoopInitNode;
 144 class OpaqueLoopStrideNode;
 145 class OpaqueMultiversioningNode;
 146 class OpaqueNotNullNode;
 147 class OpaqueInitializedAssertionPredicateNode;
 148 class OpaqueTemplateAssertionPredicateNode;
 149 class OuterStripMinedLoopNode;
 150 class OuterStripMinedLoopEndNode;
 151 class Node;
 152 class Node_Array;
 153 class Node_List;
 154 class Node_Stack;
 155 class OopMap;
 156 class ParmNode;
 157 class ParsePredicateNode;
 158 class PCTableNode;
 159 class PhaseCCP;
 160 class PhaseGVN;
 161 class PhaseIdealLoop;
 162 class PhaseIterGVN;
 163 class PhaseRegAlloc;
 164 class PhaseTransform;
 165 class PhaseValues;
 166 class PhiNode;
 167 class Pipeline;
 168 class PopulateIndexNode;
 169 class ProjNode;
 170 class RangeCheckNode;
 171 class ReductionNode;
 172 class RegMask;
 173 class RegionNode;
 174 class RootNode;
 175 class SafePointNode;
 176 class SafePointScalarObjectNode;
 177 class SafePointScalarMergeNode;
 178 class SaturatingVectorNode;
 179 class StartNode;
 180 class State;
 181 class StoreNode;
 182 class SubNode;
 183 class SubTypeCheckNode;
 184 class Type;
 185 class TypeNode;
 186 class UnlockNode;
 187 class VectorNode;
 188 class LoadVectorNode;
 189 class LoadVectorMaskedNode;
 190 class StoreVectorMaskedNode;
 191 class LoadVectorGatherNode;
 192 class LoadVectorGatherMaskedNode;
 193 class StoreVectorNode;
 194 class StoreVectorScatterNode;
 195 class StoreVectorScatterMaskedNode;
 196 class VerifyVectorAlignmentNode;
 197 class VectorMaskCmpNode;
 198 class VectorUnboxNode;
 199 class VectorSet;
 200 class VectorReinterpretNode;
 201 class ShiftVNode;
 202 class MulVLNode;
 203 class ExpandVNode;
 204 class CompressVNode;
 205 class CompressMNode;
 206 class C2_MacroAssembler;
 207 
 208 
 209 #ifndef OPTO_DU_ITERATOR_ASSERT
 210 #ifdef ASSERT
 211 #define OPTO_DU_ITERATOR_ASSERT 1
 212 #else
 213 #define OPTO_DU_ITERATOR_ASSERT 0
 214 #endif
 215 #endif //OPTO_DU_ITERATOR_ASSERT
 216 
 217 #if OPTO_DU_ITERATOR_ASSERT
 218 class DUIterator;
 219 class DUIterator_Fast;
 220 class DUIterator_Last;
 221 #else
 222 typedef uint   DUIterator;
 223 typedef Node** DUIterator_Fast;
 224 typedef Node** DUIterator_Last;
 225 #endif
 226 
 227 typedef ResizeableHashTable<Node*, Node*, AnyObj::RESOURCE_AREA, mtCompiler> OrigToNewHashtable;
 228 
 229 // Node Sentinel
 230 #define NodeSentinel (Node*)-1
 231 
 232 // Unknown count frequency
 233 #define COUNT_UNKNOWN (-1.0f)
 234 
 235 //------------------------------Node-------------------------------------------
 236 // Nodes define actions in the program.  They create values, which have types.
 237 // They are both vertices in a directed graph and program primitives.  Nodes
 238 // are labeled; the label is the "opcode", the primitive function in the lambda
 239 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 240 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 241 // the Node's function.  These inputs also define a Type equation for the Node.
 242 // Solving these Type equations amounts to doing dataflow analysis.
 243 // Control and data are uniformly represented in the graph.  Finally, Nodes
 244 // have a unique dense integer index which is used to index into side arrays
 245 // whenever I have phase-specific information.
 246 
 247 class Node {
 248 
 249   // Lots of restrictions on cloning Nodes
 250   NONCOPYABLE(Node);
 251 
 252 public:
 253   friend class Compile;
 254   #if OPTO_DU_ITERATOR_ASSERT
 255   friend class DUIterator_Common;
 256   friend class DUIterator;
 257   friend class DUIterator_Fast;
 258   friend class DUIterator_Last;
 259   #endif
 260 
 261   // Because Nodes come and go, I define an Arena of Node structures to pull
 262   // from.  This should allow fast access to node creation & deletion.  This
 263   // field is a local cache of a value defined in some "program fragment" for
 264   // which these Nodes are just a part of.
 265 
 266   inline void* operator new(size_t x) throw() {
 267     Compile* C = Compile::current();
 268     Node* n = (Node*)C->node_arena()->AmallocWords(x);
 269     return (void*)n;
 270   }
 271 
 272   // Delete is a NOP
 273   void operator delete( void *ptr ) {}
 274   // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 275   void destruct(PhaseValues* phase);
 276 
 277   // Create a new Node.  Required is the number is of inputs required for
 278   // semantic correctness.
 279   Node( uint required );
 280 
 281   // Create a new Node with given input edges.
 282   // This version requires use of the "edge-count" new.
 283   // E.g.  new (C,3) FooNode( C, nullptr, left, right );
 284   Node( Node *n0 );
 285   Node( Node *n0, Node *n1 );
 286   Node( Node *n0, Node *n1, Node *n2 );
 287   Node( Node *n0, Node *n1, Node *n2, Node *n3 );
 288   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
 289   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
 290   Node( Node *n0, Node *n1, Node *n2, Node *n3,
 291             Node *n4, Node *n5, Node *n6 );
 292 
 293   // Clone an inherited Node given only the base Node type.
 294   Node* clone() const;
 295 
 296   // Clone a Node, immediately supplying one or two new edges.
 297   // The first and second arguments, if non-null, replace in(1) and in(2),
 298   // respectively.
 299   Node* clone_with_data_edge(Node* in1, Node* in2 = nullptr) const {
 300     Node* nn = clone();
 301     if (in1 != nullptr)  nn->set_req(1, in1);
 302     if (in2 != nullptr)  nn->set_req(2, in2);
 303     return nn;
 304   }
 305 
 306 private:
 307   // Shared setup for the above constructors.
 308   // Handles all interactions with Compile::current.
 309   // Puts initial values in all Node fields except _idx.
 310   // Returns the initial value for _idx, which cannot
 311   // be initialized by assignment.
 312   inline int Init(int req);
 313 
 314 //----------------- input edge handling
 315 protected:
 316   friend class PhaseCFG;        // Access to address of _in array elements
 317   Node **_in;                   // Array of use-def references to Nodes
 318   Node **_out;                  // Array of def-use references to Nodes
 319 
 320   // Input edges are split into two categories.  Required edges are required
 321   // for semantic correctness; order is important and nulls are allowed.
 322   // Precedence edges are used to help determine execution order and are
 323   // added, e.g., for scheduling purposes.  They are unordered and not
 324   // duplicated; they have no embedded nulls.  Edges from 0 to _cnt-1
 325   // are required, from _cnt to _max-1 are precedence edges.
 326   node_idx_t _cnt;              // Total number of required Node inputs.
 327 
 328   node_idx_t _max;              // Actual length of input array.
 329 
 330   // Output edges are an unordered list of def-use edges which exactly
 331   // correspond to required input edges which point from other nodes
 332   // to this one.  Thus the count of the output edges is the number of
 333   // users of this node.
 334   node_idx_t _outcnt;           // Total number of Node outputs.
 335 
 336   node_idx_t _outmax;           // Actual length of output array.
 337 
 338   // Grow the actual input array to the next larger power-of-2 bigger than len.
 339   void grow( uint len );
 340   // Grow the output array to the next larger power-of-2 bigger than len.
 341   void out_grow( uint len );
 342   // Resize input or output array to grow it to the next larger power-of-2
 343   // bigger than len.
 344   void resize_array(Node**& array, node_idx_t& max_size, uint len, bool needs_clearing);
 345 
 346 public:
 347   // Each Node is assigned a unique small/dense number. This number is used
 348   // to index into auxiliary arrays of data and bit vectors.
 349   // The value of _idx can be changed using the set_idx() method.
 350   //
 351   // The PhaseRenumberLive phase renumbers nodes based on liveness information.
 352   // Therefore, it updates the value of the _idx field. The parse-time _idx is
 353   // preserved in _parse_idx.
 354   node_idx_t _idx;
 355   DEBUG_ONLY(const node_idx_t _parse_idx;)
 356   // IGV node identifier. Two nodes, possibly in different compilation phases,
 357   // have the same IGV identifier if (and only if) they are the very same node
 358   // (same memory address) or one is "derived" from the other (by e.g.
 359   // renumbering or matching). This identifier makes it possible to follow the
 360   // entire lifetime of a node in IGV even if its C2 identifier (_idx) changes.
 361   NOT_PRODUCT(node_idx_t _igv_idx;)
 362 
 363   // Get the (read-only) number of input edges
 364   uint req() const { return _cnt; }
 365   uint len() const { return _max; }
 366   // Get the (read-only) number of output edges
 367   uint outcnt() const { return _outcnt; }
 368 
 369 #if OPTO_DU_ITERATOR_ASSERT
 370   // Iterate over the out-edges of this node.  Deletions are illegal.
 371   inline DUIterator outs() const;
 372   // Use this when the out array might have changed to suppress asserts.
 373   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 374   // Does the node have an out at this position?  (Used for iteration.)
 375   inline bool has_out(DUIterator& i) const;
 376   inline Node*    out(DUIterator& i) const;
 377   // Iterate over the out-edges of this node.  All changes are illegal.
 378   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 379   inline Node*    fast_out(DUIterator_Fast& i) const;
 380   // Iterate over the out-edges of this node, deleting one at a time.
 381   inline DUIterator_Last last_outs(DUIterator_Last& min) const;
 382   inline Node*    last_out(DUIterator_Last& i) const;
 383   // The inline bodies of all these methods are after the iterator definitions.
 384 #else
 385   // Iterate over the out-edges of this node.  Deletions are illegal.
 386   // This iteration uses integral indexes, to decouple from array reallocations.
 387   DUIterator outs() const  { return 0; }
 388   // Use this when the out array might have changed to suppress asserts.
 389   DUIterator refresh_out_pos(DUIterator i) const { return i; }
 390 
 391   // Reference to the i'th output Node.  Error if out of bounds.
 392   Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
 393   // Does the node have an out at this position?  (Used for iteration.)
 394   bool has_out(DUIterator i) const { return i < _outcnt; }
 395 
 396   // Iterate over the out-edges of this node.  All changes are illegal.
 397   // This iteration uses a pointer internal to the out array.
 398   DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
 399     Node** out = _out;
 400     // Assign a limit pointer to the reference argument:
 401     max = out + (ptrdiff_t)_outcnt;
 402     // Return the base pointer:
 403     return out;
 404   }
 405   Node*    fast_out(DUIterator_Fast i) const  { return *i; }
 406   // Iterate over the out-edges of this node, deleting one at a time.
 407   // This iteration uses a pointer internal to the out array.
 408   DUIterator_Last last_outs(DUIterator_Last& min) const {
 409     Node** out = _out;
 410     // Assign a limit pointer to the reference argument:
 411     min = out;
 412     // Return the pointer to the start of the iteration:
 413     return out + (ptrdiff_t)_outcnt - 1;
 414   }
 415   Node*    last_out(DUIterator_Last i) const  { return *i; }
 416 #endif
 417 
 418   // Reference to the i'th input Node.  Error if out of bounds.
 419   Node* in(uint i) const { assert(i < _max, "oob: i=%d, _max=%d", i, _max); return _in[i]; }
 420   // Reference to the i'th input Node.  null if out of bounds.
 421   Node* lookup(uint i) const { return ((i < _max) ? _in[i] : nullptr); }
 422   // Reference to the i'th output Node.  Error if out of bounds.
 423   // Use this accessor sparingly.  We are going trying to use iterators instead.
 424   Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
 425   // Return the unique out edge.
 426   Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
 427 
 428   // In some cases, a node n is only used by a single use, but the use may use
 429   // n once or multiple times:
 430   //   use = ConvF2I(this)
 431   //   use = AddI(this, this)
 432   Node* unique_multiple_edges_out_or_null() const;
 433 
 434   // Delete out edge at position 'i' by moving last out edge to position 'i'
 435   void  raw_del_out(uint i) {
 436     assert(i < _outcnt,"oob");
 437     assert(_outcnt > 0,"oob");
 438     #if OPTO_DU_ITERATOR_ASSERT
 439     // Record that a change happened here.
 440     DEBUG_ONLY(_last_del = _out[i]; ++_del_tick);
 441     #endif
 442     _out[i] = _out[--_outcnt];
 443     // Smash the old edge so it can't be used accidentally.
 444     DEBUG_ONLY(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 445   }
 446 
 447 #ifdef ASSERT
 448   bool is_dead() const;
 449   static bool is_not_dead(const Node* n);
 450   bool is_reachable_from_root() const;
 451 #endif
 452   // Check whether node has become unreachable
 453   bool is_unreachable(PhaseIterGVN &igvn) const;
 454 
 455   // Set a required input edge, also updates corresponding output edge
 456   void add_req( Node *n ); // Append a NEW required input
 457   void add_req( Node *n0, Node *n1 ) {
 458     add_req(n0); add_req(n1); }
 459   void add_req( Node *n0, Node *n1, Node *n2 ) {
 460     add_req(n0); add_req(n1); add_req(n2); }
 461   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 462   void del_req( uint idx ); // Delete required edge & compact
 463   void del_req_ordered( uint idx ); // Delete required edge & compact with preserved order
 464   void ins_req( uint i, Node *n ); // Insert a NEW required input
 465   void set_req( uint i, Node *n ) {
 466     assert( is_not_dead(n), "can not use dead node");
 467     assert( i < _cnt, "oob: i=%d, _cnt=%d", i, _cnt);
 468     assert( !VerifyHashTableKeys || _hash_lock == 0,
 469             "remove node from hash table before modifying it");
 470     Node** p = &_in[i];    // cache this._in, across the del_out call
 471     if (*p != nullptr)  (*p)->del_out((Node *)this);
 472     (*p) = n;
 473     if (n != nullptr)      n->add_out((Node *)this);
 474     Compile::current()->record_modified_node(this);
 475   }
 476   // Light version of set_req() to init inputs after node creation.
 477   void init_req( uint i, Node *n ) {
 478     assert( (i == 0 && this == n) ||
 479             is_not_dead(n), "can not use dead node");
 480     assert( i < _cnt, "oob");
 481     assert( !VerifyHashTableKeys || _hash_lock == 0,
 482             "remove node from hash table before modifying it");
 483     assert( _in[i] == nullptr, "sanity");
 484     _in[i] = n;
 485     if (n != nullptr)      n->add_out((Node *)this);
 486     Compile::current()->record_modified_node(this);
 487   }
 488   // Find first occurrence of n among my edges:
 489   int find_edge(Node* n);
 490   int find_prec_edge(Node* n) {
 491     for (uint i = req(); i < len(); i++) {
 492       if (_in[i] == n) return i;
 493       if (_in[i] == nullptr) {
 494         DEBUG_ONLY( while ((++i) < len()) assert(_in[i] == nullptr, "Gap in prec edges!"); )
 495         break;
 496       }
 497     }
 498     return -1;
 499   }
 500   int replace_edge(Node* old, Node* neww, PhaseGVN* gvn = nullptr);
 501   int replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn);
 502   // null out all inputs to eliminate incoming Def-Use edges.
 503   void disconnect_inputs(Compile* C);
 504 
 505   // Quickly, return true if and only if I am Compile::current()->top().
 506   bool is_top() const {
 507     assert((this == (Node*) Compile::current()->top()) == (_out == nullptr), "");
 508     return (_out == nullptr);
 509   }
 510   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 511   void setup_is_top();
 512 
 513   // Strip away casting.  (It is depth-limited.)
 514   Node* uncast(bool keep_deps = false) const;
 515   // Return whether two Nodes are equivalent, after stripping casting.
 516   bool eqv_uncast(const Node* n, bool keep_deps = false) const {
 517     return (this->uncast(keep_deps) == n->uncast(keep_deps));
 518   }
 519 
 520   // Find out of current node that matches opcode.
 521   Node* find_out_with(int opcode);
 522   // Return true if the current node has an out that matches opcode.
 523   bool has_out_with(int opcode);
 524   // Return true if the current node has an out that matches any of the opcodes.
 525   bool has_out_with(int opcode1, int opcode2, int opcode3, int opcode4);
 526 
 527 private:
 528   static Node* uncast_helper(const Node* n, bool keep_deps);
 529 
 530   // Add an output edge to the end of the list
 531   void add_out( Node *n ) {
 532     if (is_top())  return;
 533     if( _outcnt == _outmax ) out_grow(_outcnt);
 534     _out[_outcnt++] = n;
 535   }
 536   // Delete an output edge
 537   void del_out( Node *n ) {
 538     if (is_top())  return;
 539     Node** outp = &_out[_outcnt];
 540     // Find and remove n
 541     do {
 542       assert(outp > _out, "Missing Def-Use edge");
 543     } while (*--outp != n);
 544     *outp = _out[--_outcnt];
 545     // Smash the old edge so it can't be used accidentally.
 546     DEBUG_ONLY(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 547     // Record that a change happened here.
 548     #if OPTO_DU_ITERATOR_ASSERT
 549     DEBUG_ONLY(_last_del = n; ++_del_tick);
 550     #endif
 551   }
 552   // Close gap after removing edge.
 553   void close_prec_gap_at(uint gap) {
 554     assert(_cnt <= gap && gap < _max, "no valid prec edge");
 555     uint i = gap;
 556     Node *last = nullptr;
 557     for (; i < _max-1; ++i) {
 558       Node *next = _in[i+1];
 559       if (next == nullptr) break;
 560       last = next;
 561     }
 562     _in[gap] = last;  // Move last slot to empty one.
 563     _in[i] = nullptr; // null out last slot.
 564   }
 565 
 566 public:
 567   // Globally replace this node by a given new node, updating all uses.
 568   void replace_by(Node* new_node);
 569   // Globally replace this node by a given new node, updating all uses
 570   // and cutting input edges of old node.
 571   void subsume_by(Node* new_node, Compile* c) {
 572     replace_by(new_node);
 573     disconnect_inputs(c);
 574   }
 575   void set_req_X(uint i, Node *n, PhaseIterGVN *igvn);
 576   void set_req_X(uint i, Node *n, PhaseGVN *gvn);
 577   // Find the one non-null required input.  RegionNode only
 578   Node *nonnull_req() const;
 579   // Add or remove precedence edges
 580   void add_prec( Node *n );
 581   void rm_prec( uint i );
 582 
 583   // Note: prec(i) will not necessarily point to n if edge already exists.
 584   void set_prec( uint i, Node *n ) {
 585     assert(i < _max, "oob: i=%d, _max=%d", i, _max);
 586     assert(is_not_dead(n), "can not use dead node");
 587     assert(i >= _cnt, "not a precedence edge");
 588     // Avoid spec violation: duplicated prec edge.
 589     if (_in[i] == n) return;
 590     if (n == nullptr || find_prec_edge(n) != -1) {
 591       rm_prec(i);
 592       return;
 593     }
 594     if (_in[i] != nullptr) _in[i]->del_out((Node *)this);
 595     _in[i] = n;
 596     n->add_out((Node *)this);
 597     Compile::current()->record_modified_node(this);
 598   }
 599 
 600   // Set this node's index, used by cisc_version to replace current node
 601   void set_idx(uint new_idx) {
 602     _idx = new_idx;
 603   }
 604   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 605   void swap_edges(uint i1, uint i2) {
 606     DEBUG_ONLY(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 607     // Def-Use info is unchanged
 608     Node* n1 = in(i1);
 609     Node* n2 = in(i2);
 610     _in[i1] = n2;
 611     _in[i2] = n1;
 612     // If this node is in the hash table, make sure it doesn't need a rehash.
 613     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 614     // Flip swapped edges flag.
 615     if (has_swapped_edges()) {
 616       remove_flag(Node::Flag_has_swapped_edges);
 617     } else {
 618       add_flag(Node::Flag_has_swapped_edges);
 619     }
 620   }
 621 
 622   // Iterators over input Nodes for a Node X are written as:
 623   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 624   // NOTE: Required edges can contain embedded null pointers.
 625 
 626 //----------------- Other Node Properties
 627 
 628   // Generate class IDs for (some) ideal nodes so that it is possible to determine
 629   // the type of a node using a non-virtual method call (the method is_<Node>() below).
 630   //
 631   // A class ID of an ideal node is a set of bits. In a class ID, a single bit determines
 632   // the type of the node the ID represents; another subset of an ID's bits are reserved
 633   // for the superclasses of the node represented by the ID.
 634   //
 635   // By design, if A is a supertype of B, A.is_B() returns true and B.is_A()
 636   // returns false. A.is_A() returns true.
 637   //
 638   // If two classes, A and B, have the same superclass, a different bit of A's class id
 639   // is reserved for A's type than for B's type. That bit is specified by the third
 640   // parameter in the macro DEFINE_CLASS_ID.
 641   //
 642   // By convention, classes with deeper hierarchy are declared first. Moreover,
 643   // classes with the same hierarchy depth are sorted by usage frequency.
 644   //
 645   // The query method masks the bits to cut off bits of subclasses and then compares
 646   // the result with the class id (see the macro DEFINE_CLASS_QUERY below).
 647   //
 648   //  Class_MachCall=30, ClassMask_MachCall=31
 649   // 12               8               4               0
 650   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 651   //                                  |   |   |   |
 652   //                                  |   |   |   Bit_Mach=2
 653   //                                  |   |   Bit_MachReturn=4
 654   //                                  |   Bit_MachSafePoint=8
 655   //                                  Bit_MachCall=16
 656   //
 657   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 658   // 12               8               4               0
 659   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 660   //                              |   |   |
 661   //                              |   |   Bit_Region=8
 662   //                              |   Bit_Loop=16
 663   //                              Bit_CountedLoop=32
 664 
 665   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 666   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 667   Class_##cl = Class_##supcl + Bit_##cl , \
 668   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 669 
 670   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 671   // so that its values fit into 32 bits.
 672   enum NodeClasses {
 673     Bit_Node   = 0x00000000,
 674     Class_Node = 0x00000000,
 675     ClassMask_Node = 0xFFFFFFFF,
 676 
 677     DEFINE_CLASS_ID(Multi, Node, 0)
 678       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 679         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 680           DEFINE_CLASS_ID(CallJava,         Call, 0)
 681             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 682             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 683           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 684             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 685               DEFINE_CLASS_ID(CallLeafNoFP,     CallLeaf, 0)
 686               DEFINE_CLASS_ID(CallLeafPure,     CallLeaf, 1)
 687           DEFINE_CLASS_ID(Allocate,         Call, 2)
 688             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 689           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 690             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 691             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 692           DEFINE_CLASS_ID(ArrayCopy,        Call, 4)
 693       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 694         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 695           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 696           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 697         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 698           DEFINE_CLASS_ID(BaseCountedLoopEnd,     If, 0)
 699             DEFINE_CLASS_ID(CountedLoopEnd,       BaseCountedLoopEnd, 0)
 700             DEFINE_CLASS_ID(LongCountedLoopEnd,   BaseCountedLoopEnd, 1)
 701           DEFINE_CLASS_ID(RangeCheck,             If, 1)
 702           DEFINE_CLASS_ID(OuterStripMinedLoopEnd, If, 2)
 703           DEFINE_CLASS_ID(ParsePredicate,         If, 3)
 704         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 705       DEFINE_CLASS_ID(Start,       Multi, 2)
 706       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 707         DEFINE_CLASS_ID(Initialize,       MemBar, 0)
 708         DEFINE_CLASS_ID(MemBarStoreStore, MemBar, 1)
 709 
 710     DEFINE_CLASS_ID(Mach,  Node, 1)
 711       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 712         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 713           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 714             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 715               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 716               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 717             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 718               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 719       DEFINE_CLASS_ID(MachBranch, Mach, 1)
 720         DEFINE_CLASS_ID(MachIf,         MachBranch, 0)
 721         DEFINE_CLASS_ID(MachGoto,       MachBranch, 1)
 722         DEFINE_CLASS_ID(MachNullCheck,  MachBranch, 2)
 723       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 2)
 724       DEFINE_CLASS_ID(MachTemp,         Mach, 3)
 725       DEFINE_CLASS_ID(MachConstantBase, Mach, 4)
 726       DEFINE_CLASS_ID(MachConstant,     Mach, 5)
 727         DEFINE_CLASS_ID(MachJump,       MachConstant, 0)
 728       DEFINE_CLASS_ID(MachMerge,        Mach, 6)
 729       DEFINE_CLASS_ID(MachMemBar,       Mach, 7)
 730 
 731     DEFINE_CLASS_ID(Type,  Node, 2)
 732       DEFINE_CLASS_ID(Phi,   Type, 0)
 733       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 734         DEFINE_CLASS_ID(CastII, ConstraintCast, 0)
 735         DEFINE_CLASS_ID(CheckCastPP, ConstraintCast, 1)
 736         DEFINE_CLASS_ID(CastLL, ConstraintCast, 2)
 737         DEFINE_CLASS_ID(CastFF, ConstraintCast, 3)
 738         DEFINE_CLASS_ID(CastDD, ConstraintCast, 4)
 739         DEFINE_CLASS_ID(CastVV, ConstraintCast, 5)
 740         DEFINE_CLASS_ID(CastPP, ConstraintCast, 6)
 741         DEFINE_CLASS_ID(CastHH, ConstraintCast, 7)
 742       DEFINE_CLASS_ID(CMove, Type, 3)
 743       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 744       DEFINE_CLASS_ID(DecodeNarrowPtr, Type, 5)
 745         DEFINE_CLASS_ID(DecodeN, DecodeNarrowPtr, 0)
 746         DEFINE_CLASS_ID(DecodeNKlass, DecodeNarrowPtr, 1)
 747       DEFINE_CLASS_ID(EncodeNarrowPtr, Type, 6)
 748         DEFINE_CLASS_ID(EncodeP, EncodeNarrowPtr, 0)
 749         DEFINE_CLASS_ID(EncodePKlass, EncodeNarrowPtr, 1)
 750       DEFINE_CLASS_ID(Vector, Type, 7)
 751         DEFINE_CLASS_ID(VectorMaskCmp, Vector, 0)
 752         DEFINE_CLASS_ID(VectorUnbox, Vector, 1)
 753         DEFINE_CLASS_ID(VectorReinterpret, Vector, 2)
 754         DEFINE_CLASS_ID(ShiftV, Vector, 3)
 755         DEFINE_CLASS_ID(CompressV, Vector, 4)
 756         DEFINE_CLASS_ID(ExpandV, Vector, 5)
 757         DEFINE_CLASS_ID(CompressM, Vector, 6)
 758         DEFINE_CLASS_ID(Reduction, Vector, 7)
 759         DEFINE_CLASS_ID(NegV, Vector, 8)
 760         DEFINE_CLASS_ID(SaturatingVector, Vector, 9)
 761         DEFINE_CLASS_ID(MulVL, Vector, 10)
 762       DEFINE_CLASS_ID(Con, Type, 8)
 763           DEFINE_CLASS_ID(ConI, Con, 0)
 764       DEFINE_CLASS_ID(SafePointScalarMerge, Type, 9)
 765       DEFINE_CLASS_ID(Convert, Type, 10)
 766 
 767 
 768     DEFINE_CLASS_ID(Proj,  Node, 3)
 769       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 770       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 771       DEFINE_CLASS_ID(IfProj,    Proj, 2)
 772         DEFINE_CLASS_ID(IfTrue,    IfProj, 0)
 773         DEFINE_CLASS_ID(IfFalse,   IfProj, 1)
 774       DEFINE_CLASS_ID(Parm,      Proj, 4)
 775       DEFINE_CLASS_ID(MachProj,  Proj, 5)
 776       DEFINE_CLASS_ID(NarrowMemProj, Proj, 6)
 777 
 778     DEFINE_CLASS_ID(Mem, Node, 4)
 779       DEFINE_CLASS_ID(Load, Mem, 0)
 780         DEFINE_CLASS_ID(LoadVector,  Load, 0)
 781           DEFINE_CLASS_ID(LoadVectorGather, LoadVector, 0)
 782           DEFINE_CLASS_ID(LoadVectorGatherMasked, LoadVector, 1)
 783           DEFINE_CLASS_ID(LoadVectorMasked, LoadVector, 2)
 784       DEFINE_CLASS_ID(Store, Mem, 1)
 785         DEFINE_CLASS_ID(StoreVector, Store, 0)
 786           DEFINE_CLASS_ID(StoreVectorScatter, StoreVector, 0)
 787           DEFINE_CLASS_ID(StoreVectorScatterMasked, StoreVector, 1)
 788           DEFINE_CLASS_ID(StoreVectorMasked, StoreVector, 2)
 789       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 790         DEFINE_CLASS_ID(LoadStoreConditional, LoadStore, 0)
 791           DEFINE_CLASS_ID(CompareAndSwap, LoadStoreConditional, 0)
 792         DEFINE_CLASS_ID(CompareAndExchangeNode, LoadStore, 1)
 793 
 794     DEFINE_CLASS_ID(Region, Node, 5)
 795       DEFINE_CLASS_ID(Loop, Region, 0)
 796         DEFINE_CLASS_ID(Root,                Loop, 0)
 797         DEFINE_CLASS_ID(BaseCountedLoop,     Loop, 1)
 798           DEFINE_CLASS_ID(CountedLoop,       BaseCountedLoop, 0)
 799           DEFINE_CLASS_ID(LongCountedLoop,   BaseCountedLoop, 1)
 800         DEFINE_CLASS_ID(OuterStripMinedLoop, Loop, 2)
 801 
 802     DEFINE_CLASS_ID(Sub,   Node, 6)
 803       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 804         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
 805         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
 806         DEFINE_CLASS_ID(SubTypeCheck,Cmp, 2)
 807 
 808     DEFINE_CLASS_ID(MergeMem, Node, 7)
 809     DEFINE_CLASS_ID(Bool,     Node, 8)
 810     DEFINE_CLASS_ID(AddP,     Node, 9)
 811     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 812     DEFINE_CLASS_ID(Add,      Node, 11)
 813       DEFINE_CLASS_ID(MinMax,      Add, 0)
 814     DEFINE_CLASS_ID(Mul,      Node, 12)
 815     DEFINE_CLASS_ID(ClearArray, Node, 14)
 816     DEFINE_CLASS_ID(Halt,     Node, 15)
 817     DEFINE_CLASS_ID(Opaque1,  Node, 16)
 818       DEFINE_CLASS_ID(OpaqueLoopInit, Opaque1, 0)
 819       DEFINE_CLASS_ID(OpaqueLoopStride, Opaque1, 1)
 820       DEFINE_CLASS_ID(OpaqueMultiversioning, Opaque1, 2)
 821     DEFINE_CLASS_ID(OpaqueNotNull,  Node, 17)
 822     DEFINE_CLASS_ID(OpaqueInitializedAssertionPredicate,  Node, 18)
 823     DEFINE_CLASS_ID(OpaqueTemplateAssertionPredicate,  Node, 19)
 824     DEFINE_CLASS_ID(Move,     Node, 20)
 825     DEFINE_CLASS_ID(LShift,   Node, 21)
 826     DEFINE_CLASS_ID(Neg,      Node, 22)
 827 
 828     _max_classes  = ClassMask_Neg
 829   };
 830   #undef DEFINE_CLASS_ID
 831 
 832   // Flags are sorted by usage frequency.
 833   enum NodeFlags : uint64_t {
 834     Flag_is_Copy                     = 1ULL << 0, // should be first bit to avoid shift
 835     Flag_rematerialize               = 1ULL << 1,
 836     Flag_needs_anti_dependence_check = 1ULL << 2,
 837     Flag_is_macro                    = 1ULL << 3,
 838     Flag_is_Con                      = 1ULL << 4,
 839     Flag_is_cisc_alternate           = 1ULL << 5,
 840     Flag_is_dead_loop_safe           = 1ULL << 6,
 841     Flag_may_be_short_branch         = 1ULL << 7,
 842     Flag_avoid_back_to_back_before   = 1ULL << 8,
 843     Flag_avoid_back_to_back_after    = 1ULL << 9,
 844     Flag_has_call                    = 1ULL << 10,
 845     Flag_has_swapped_edges           = 1ULL << 11,
 846     Flag_is_scheduled                = 1ULL << 12,
 847     Flag_is_expensive                = 1ULL << 13,
 848     Flag_is_predicated_vector        = 1ULL << 14, // Marked on a vector node that has an additional
 849                                                    // mask input controlling the lane operations.
 850     Flag_for_post_loop_opts_igvn     = 1ULL << 15,
 851     Flag_for_merge_stores_igvn       = 1ULL << 16,
 852     Flag_is_removed_by_peephole      = 1ULL << 17,
 853     Flag_is_predicated_using_blend   = 1ULL << 18,
 854     _last_flag                       = Flag_is_predicated_using_blend
 855   };
 856 
 857   class PD;
 858 
 859 private:
 860   juint _class_id;
 861   juint _flags;
 862 
 863 #ifdef ASSERT
 864   static juint max_flags();
 865 #endif
 866 
 867 protected:
 868   // These methods should be called from constructors only.
 869   void init_class_id(juint c) {
 870     _class_id = c; // cast out const
 871   }
 872   void init_flags(uint fl) {
 873     assert(fl <= max_flags(), "invalid node flag");
 874     _flags |= fl;
 875   }
 876   void clear_flag(uint fl) {
 877     assert(fl <= max_flags(), "invalid node flag");
 878     _flags &= ~fl;
 879   }
 880 
 881 public:
 882   juint class_id() const { return _class_id; }
 883 
 884   juint flags() const { return _flags; }
 885 
 886   void add_flag(juint fl) { init_flags(fl); }
 887 
 888   void remove_flag(juint fl) { clear_flag(fl); }
 889 
 890   // Return a dense integer opcode number
 891   virtual int Opcode() const;
 892 
 893   // Virtual inherited Node size
 894   virtual uint size_of() const;
 895 
 896   // Other interesting Node properties
 897   #define DEFINE_CLASS_QUERY(type)                           \
 898   bool is_##type() const {                                   \
 899     return ((_class_id & ClassMask_##type) == Class_##type); \
 900   }                                                          \
 901   type##Node *as_##type() const {                            \
 902     assert(is_##type(), "invalid node class: %s", Name());   \
 903     return (type##Node*)this;                                \
 904   }                                                          \
 905   type##Node* isa_##type() const {                           \
 906     return (is_##type()) ? as_##type() : nullptr;            \
 907   }
 908 
 909   DEFINE_CLASS_QUERY(AbstractLock)
 910   DEFINE_CLASS_QUERY(Add)
 911   DEFINE_CLASS_QUERY(AddP)
 912   DEFINE_CLASS_QUERY(Allocate)
 913   DEFINE_CLASS_QUERY(AllocateArray)
 914   DEFINE_CLASS_QUERY(ArrayCopy)
 915   DEFINE_CLASS_QUERY(BaseCountedLoop)
 916   DEFINE_CLASS_QUERY(BaseCountedLoopEnd)
 917   DEFINE_CLASS_QUERY(Bool)
 918   DEFINE_CLASS_QUERY(BoxLock)
 919   DEFINE_CLASS_QUERY(Call)
 920   DEFINE_CLASS_QUERY(CallDynamicJava)
 921   DEFINE_CLASS_QUERY(CallJava)
 922   DEFINE_CLASS_QUERY(CallLeaf)
 923   DEFINE_CLASS_QUERY(CallLeafNoFP)
 924   DEFINE_CLASS_QUERY(CallLeafPure)
 925   DEFINE_CLASS_QUERY(CallRuntime)
 926   DEFINE_CLASS_QUERY(CallStaticJava)
 927   DEFINE_CLASS_QUERY(Catch)
 928   DEFINE_CLASS_QUERY(CatchProj)
 929   DEFINE_CLASS_QUERY(CheckCastPP)
 930   DEFINE_CLASS_QUERY(CastII)
 931   DEFINE_CLASS_QUERY(CastLL)
 932   DEFINE_CLASS_QUERY(CastFF)
 933   DEFINE_CLASS_QUERY(ConI)
 934   DEFINE_CLASS_QUERY(CastPP)
 935   DEFINE_CLASS_QUERY(ConstraintCast)
 936   DEFINE_CLASS_QUERY(ClearArray)
 937   DEFINE_CLASS_QUERY(CMove)
 938   DEFINE_CLASS_QUERY(Cmp)
 939   DEFINE_CLASS_QUERY(Convert)
 940   DEFINE_CLASS_QUERY(CountedLoop)
 941   DEFINE_CLASS_QUERY(CountedLoopEnd)
 942   DEFINE_CLASS_QUERY(DecodeNarrowPtr)
 943   DEFINE_CLASS_QUERY(DecodeN)
 944   DEFINE_CLASS_QUERY(DecodeNKlass)
 945   DEFINE_CLASS_QUERY(EncodeNarrowPtr)
 946   DEFINE_CLASS_QUERY(EncodeP)
 947   DEFINE_CLASS_QUERY(EncodePKlass)
 948   DEFINE_CLASS_QUERY(FastLock)
 949   DEFINE_CLASS_QUERY(FastUnlock)
 950   DEFINE_CLASS_QUERY(Halt)
 951   DEFINE_CLASS_QUERY(If)
 952   DEFINE_CLASS_QUERY(RangeCheck)
 953   DEFINE_CLASS_QUERY(IfProj)
 954   DEFINE_CLASS_QUERY(IfFalse)
 955   DEFINE_CLASS_QUERY(IfTrue)
 956   DEFINE_CLASS_QUERY(Initialize)
 957   DEFINE_CLASS_QUERY(Jump)
 958   DEFINE_CLASS_QUERY(JumpProj)
 959   DEFINE_CLASS_QUERY(LongCountedLoop)
 960   DEFINE_CLASS_QUERY(LongCountedLoopEnd)
 961   DEFINE_CLASS_QUERY(Load)
 962   DEFINE_CLASS_QUERY(LoadStore)
 963   DEFINE_CLASS_QUERY(LoadStoreConditional)
 964   DEFINE_CLASS_QUERY(Lock)
 965   DEFINE_CLASS_QUERY(Loop)
 966   DEFINE_CLASS_QUERY(LShift)
 967   DEFINE_CLASS_QUERY(Mach)
 968   DEFINE_CLASS_QUERY(MachBranch)
 969   DEFINE_CLASS_QUERY(MachCall)
 970   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 971   DEFINE_CLASS_QUERY(MachCallJava)
 972   DEFINE_CLASS_QUERY(MachCallLeaf)
 973   DEFINE_CLASS_QUERY(MachCallRuntime)
 974   DEFINE_CLASS_QUERY(MachCallStaticJava)
 975   DEFINE_CLASS_QUERY(MachConstantBase)
 976   DEFINE_CLASS_QUERY(MachConstant)
 977   DEFINE_CLASS_QUERY(MachGoto)
 978   DEFINE_CLASS_QUERY(MachIf)
 979   DEFINE_CLASS_QUERY(MachJump)
 980   DEFINE_CLASS_QUERY(MachNullCheck)
 981   DEFINE_CLASS_QUERY(MachProj)
 982   DEFINE_CLASS_QUERY(MachReturn)
 983   DEFINE_CLASS_QUERY(MachSafePoint)
 984   DEFINE_CLASS_QUERY(MachSpillCopy)
 985   DEFINE_CLASS_QUERY(MachTemp)
 986   DEFINE_CLASS_QUERY(MachMemBar)
 987   DEFINE_CLASS_QUERY(MachMerge)
 988   DEFINE_CLASS_QUERY(Mem)
 989   DEFINE_CLASS_QUERY(MemBar)
 990   DEFINE_CLASS_QUERY(MemBarStoreStore)
 991   DEFINE_CLASS_QUERY(MergeMem)
 992   DEFINE_CLASS_QUERY(MinMax)
 993   DEFINE_CLASS_QUERY(Move)
 994   DEFINE_CLASS_QUERY(Mul)
 995   DEFINE_CLASS_QUERY(Multi)
 996   DEFINE_CLASS_QUERY(MultiBranch)
 997   DEFINE_CLASS_QUERY(MulVL)
 998   DEFINE_CLASS_QUERY(NarrowMemProj)
 999   DEFINE_CLASS_QUERY(Neg)
1000   DEFINE_CLASS_QUERY(NegV)
1001   DEFINE_CLASS_QUERY(NeverBranch)
1002   DEFINE_CLASS_QUERY(Opaque1)
1003   DEFINE_CLASS_QUERY(OpaqueNotNull)
1004   DEFINE_CLASS_QUERY(OpaqueInitializedAssertionPredicate)
1005   DEFINE_CLASS_QUERY(OpaqueTemplateAssertionPredicate)
1006   DEFINE_CLASS_QUERY(OpaqueLoopInit)
1007   DEFINE_CLASS_QUERY(OpaqueLoopStride)
1008   DEFINE_CLASS_QUERY(OpaqueMultiversioning)
1009   DEFINE_CLASS_QUERY(OuterStripMinedLoop)
1010   DEFINE_CLASS_QUERY(OuterStripMinedLoopEnd)
1011   DEFINE_CLASS_QUERY(Parm)
1012   DEFINE_CLASS_QUERY(ParsePredicate)
1013   DEFINE_CLASS_QUERY(PCTable)
1014   DEFINE_CLASS_QUERY(Phi)
1015   DEFINE_CLASS_QUERY(Proj)
1016   DEFINE_CLASS_QUERY(Reduction)
1017   DEFINE_CLASS_QUERY(Region)
1018   DEFINE_CLASS_QUERY(Root)
1019   DEFINE_CLASS_QUERY(SafePoint)
1020   DEFINE_CLASS_QUERY(SafePointScalarObject)
1021   DEFINE_CLASS_QUERY(SafePointScalarMerge)
1022   DEFINE_CLASS_QUERY(Start)
1023   DEFINE_CLASS_QUERY(Store)
1024   DEFINE_CLASS_QUERY(Sub)
1025   DEFINE_CLASS_QUERY(SubTypeCheck)
1026   DEFINE_CLASS_QUERY(Type)
1027   DEFINE_CLASS_QUERY(Vector)
1028   DEFINE_CLASS_QUERY(VectorMaskCmp)
1029   DEFINE_CLASS_QUERY(VectorUnbox)
1030   DEFINE_CLASS_QUERY(VectorReinterpret)
1031   DEFINE_CLASS_QUERY(CompressV)
1032   DEFINE_CLASS_QUERY(ExpandV)
1033   DEFINE_CLASS_QUERY(CompressM)
1034   DEFINE_CLASS_QUERY(LoadVector)
1035   DEFINE_CLASS_QUERY(LoadVectorGather)
1036   DEFINE_CLASS_QUERY(LoadVectorMasked)
1037   DEFINE_CLASS_QUERY(LoadVectorGatherMasked)
1038   DEFINE_CLASS_QUERY(StoreVector)
1039   DEFINE_CLASS_QUERY(StoreVectorScatter)
1040   DEFINE_CLASS_QUERY(StoreVectorMasked)
1041   DEFINE_CLASS_QUERY(StoreVectorScatterMasked)
1042   DEFINE_CLASS_QUERY(SaturatingVector)
1043   DEFINE_CLASS_QUERY(ShiftV)
1044   DEFINE_CLASS_QUERY(Unlock)
1045 
1046   #undef DEFINE_CLASS_QUERY
1047 
1048   // duplicate of is_MachSpillCopy()
1049   bool is_SpillCopy () const {
1050     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
1051   }
1052 
1053   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
1054   // The data node which is safe to leave in dead loop during IGVN optimization.
1055   bool is_dead_loop_safe() const;
1056 
1057   // is_Copy() returns copied edge index (0 or 1)
1058   uint is_Copy() const { return (_flags & Flag_is_Copy); }
1059 
1060   virtual bool is_CFG() const { return false; }
1061 
1062   // If this node is control-dependent on a test, can it be
1063   // rerouted to a dominating equivalent test?  This is usually
1064   // true of non-CFG nodes, but can be false for operations which
1065   // depend for their correct sequencing on more than one test.
1066   // (In that case, hoisting to a dominating test may silently
1067   // skip some other important test.)
1068   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
1069 
1070   // When building basic blocks, I need to have a notion of block beginning
1071   // Nodes, next block selector Nodes (block enders), and next block
1072   // projections.  These calls need to work on their machine equivalents.  The
1073   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
1074   bool is_block_start() const {
1075     if ( is_Region() )
1076       return this == (const Node*)in(0);
1077     else
1078       return is_Start();
1079   }
1080 
1081   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
1082   // Goto and Return.  This call also returns the block ending Node.
1083   virtual const Node *is_block_proj() const;
1084 
1085   // The node is a "macro" node which needs to be expanded before matching
1086   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
1087   // The node is expensive: the best control is set during loop opts
1088   bool is_expensive() const { return (_flags & Flag_is_expensive) != 0 && in(0) != nullptr; }
1089   // The node's original edge position is swapped.
1090   bool has_swapped_edges() const { return (_flags & Flag_has_swapped_edges) != 0; }
1091 
1092   bool is_predicated_vector() const { return (_flags & Flag_is_predicated_vector) != 0; }
1093 
1094   bool is_predicated_using_blend() const { return (_flags & Flag_is_predicated_using_blend) != 0; }
1095 
1096   // Used in lcm to mark nodes that have scheduled
1097   bool is_scheduled() const { return (_flags & Flag_is_scheduled) != 0; }
1098 
1099   bool for_post_loop_opts_igvn() const { return (_flags & Flag_for_post_loop_opts_igvn) != 0; }
1100   bool for_merge_stores_igvn() const { return (_flags & Flag_for_merge_stores_igvn) != 0; }
1101 
1102   // Is 'n' possibly a loop entry (i.e. a Parse Predicate projection)?
1103   static bool may_be_loop_entry(Node* n) {
1104     return n != nullptr && n->is_IfProj() && n->in(0)->is_ParsePredicate();
1105   }
1106 
1107 //----------------- Optimization
1108 
1109   // Get the worst-case Type output for this Node.
1110   virtual const class Type *bottom_type() const;
1111 
1112   // If we find a better type for a node, try to record it permanently.
1113   // Return true if this node actually changed.
1114   // Be sure to do the hash_delete game in the "rehash" variant.
1115   void raise_bottom_type(const Type* new_type);
1116 
1117   // Get the address type with which this node uses and/or defs memory,
1118   // or null if none.  The address type is conservatively wide.
1119   // Returns non-null for calls, membars, loads, stores, etc.
1120   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
1121   virtual const class TypePtr *adr_type() const { return nullptr; }
1122 
1123   // Return an existing node which computes the same function as this node.
1124   // The optimistic combined algorithm requires this to return a Node which
1125   // is a small number of steps away (e.g., one of my inputs).
1126   virtual Node* Identity(PhaseGVN* phase);
1127 
1128   // Return the set of values this Node can take on at runtime.
1129   virtual const Type* Value(PhaseGVN* phase) const;
1130 
1131   // Return a node which is more "ideal" than the current node.
1132   // The invariants on this call are subtle.  If in doubt, read the
1133   // treatise in node.cpp above the default implementation AND TEST WITH
1134   // -XX:VerifyIterativeGVN=1
1135   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1136 
1137   // Some nodes have specific Ideal subgraph transformations only if they are
1138   // unique users of specific nodes. Such nodes should be put on IGVN worklist
1139   // for the transformations to happen.
1140   bool has_special_unique_user() const;
1141 
1142   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1143   Node* find_exact_control(Node* ctrl);
1144 
1145   // Results of the dominance analysis.
1146   enum class DomResult {
1147     NotDominate,         // 'this' node does not dominate 'sub'.
1148     Dominate,            // 'this' node dominates or is equal to 'sub'.
1149     EncounteredDeadCode  // Result is undefined due to encountering dead code.
1150   };
1151   // Check if 'this' node dominates or equal to 'sub'.
1152   DomResult dominates(Node* sub, Node_List &nlist);
1153 
1154   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
1155 public:
1156 
1157   // See if there is valid pipeline info
1158   static  const Pipeline *pipeline_class();
1159   virtual const Pipeline *pipeline() const;
1160 
1161   // Compute the latency from the def to this instruction of the ith input node
1162   uint latency(uint i);
1163 
1164   // Hash & compare functions, for pessimistic value numbering
1165 
1166   // If the hash function returns the special sentinel value NO_HASH,
1167   // the node is guaranteed never to compare equal to any other node.
1168   // If we accidentally generate a hash with value NO_HASH the node
1169   // won't go into the table and we'll lose a little optimization.
1170   static const uint NO_HASH = 0;
1171   virtual uint hash() const;
1172   virtual bool cmp( const Node &n ) const;
1173 
1174   // Operation appears to be iteratively computed (such as an induction variable)
1175   // It is possible for this operation to return false for a loop-varying
1176   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1177   bool is_iteratively_computed();
1178 
1179   // Determine if a node is a counted loop induction variable.
1180   // NOTE: The method is defined in "loopnode.cpp".
1181   bool is_cloop_ind_var() const;
1182 
1183   // Return a node with opcode "opc" and same inputs as "this" if one can
1184   // be found; Otherwise return null;
1185   Node* find_similar(int opc);
1186   bool has_same_inputs_as(const Node* other) const;
1187 
1188   // Return the unique control out if only one. Null if none or more than one.
1189   Node* unique_ctrl_out_or_null() const;
1190   // Return the unique control out. Asserts if none or more than one control out.
1191   Node* unique_ctrl_out() const;
1192 
1193   // Set control or add control as precedence edge
1194   void ensure_control_or_add_prec(Node* c);
1195   void add_prec_from(Node* n);
1196 
1197   // Visit boundary uses of the node and apply a callback function for each.
1198   // Recursively traverse uses, stopping and applying the callback when
1199   // reaching a boundary node, defined by is_boundary. Note: the function
1200   // definition appears after the complete type definition of Node_List.
1201   template <typename Callback, typename Check>
1202   void visit_uses(Callback callback, Check is_boundary) const;
1203 
1204   // Returns a clone of the current node that's pinned (if the current node is not) for nodes found in array accesses
1205   // (Load and range check CastII nodes).
1206   // This is used when an array access is made dependent on 2 or more range checks (range check smearing or Loop Predication).
1207   virtual Node* pin_array_access_node() const {
1208     return nullptr;
1209   }
1210 
1211   //----------------- Code Generation
1212 
1213   // Ideal register class for Matching.  Zero means unmatched instruction
1214   // (these are cloned instead of converted to machine nodes).
1215   virtual uint ideal_reg() const;
1216 
1217   static const uint NotAMachineReg;   // must be > max. machine register
1218 
1219   // Do we Match on this edge index or not?  Generally false for Control
1220   // and true for everything else.  Weird for calls & returns.
1221   virtual uint match_edge(uint idx) const;
1222 
1223   // Register class output is returned in
1224   virtual const RegMask &out_RegMask() const;
1225   // Register class input is expected in
1226   virtual const RegMask &in_RegMask(uint) const;
1227   // Should we clone rather than spill this instruction?
1228   bool rematerialize() const;
1229 
1230   // Return JVM State Object if this Node carries debug info, or null otherwise
1231   virtual JVMState* jvms() const;
1232 
1233   // Print as assembly
1234   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
1235   // Emit bytes using C2_MacroAssembler
1236   virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const;
1237   // Size of instruction in bytes
1238   virtual uint size(PhaseRegAlloc *ra_) const;
1239 
1240   // Convenience function to extract an integer constant from a node.
1241   // If it is not an integer constant (either Con, CastII, or Mach),
1242   // return value_if_unknown.
1243   jint find_int_con(jint value_if_unknown) const {
1244     const TypeInt* t = find_int_type();
1245     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1246   }
1247   // Return the constant, knowing it is an integer constant already
1248   jint get_int() const {
1249     const TypeInt* t = find_int_type();
1250     guarantee(t != nullptr, "must be con");
1251     return t->get_con();
1252   }
1253   // Here's where the work is done.  Can produce non-constant int types too.
1254   const TypeInt* find_int_type() const;
1255   const TypeInteger* find_integer_type(BasicType bt) const;
1256 
1257   // Same thing for long (and intptr_t, via type.hpp):
1258   jlong get_long() const {
1259     const TypeLong* t = find_long_type();
1260     guarantee(t != nullptr, "must be con");
1261     return t->get_con();
1262   }
1263   jlong find_long_con(jint value_if_unknown) const {
1264     const TypeLong* t = find_long_type();
1265     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1266   }
1267   const TypeLong* find_long_type() const;
1268 
1269   jlong get_integer_as_long(BasicType bt) const {
1270     const TypeInteger* t = find_integer_type(bt);
1271     guarantee(t != nullptr && t->is_con(), "must be con");
1272     return t->get_con_as_long(bt);
1273   }
1274   jlong find_integer_as_long(BasicType bt, jlong value_if_unknown) const {
1275     const TypeInteger* t = find_integer_type(bt);
1276     if (t == nullptr || !t->is_con())  return value_if_unknown;
1277     return t->get_con_as_long(bt);
1278   }
1279   const TypePtr* get_ptr_type() const;
1280 
1281   // These guys are called by code generated by ADLC:
1282   intptr_t get_ptr() const;
1283   intptr_t get_narrowcon() const;
1284   jdouble getd() const;
1285   jfloat getf() const;
1286   jshort geth() const;
1287 
1288   // Nodes which are pinned into basic blocks
1289   virtual bool pinned() const { return false; }
1290 
1291   // Nodes which use memory without consuming it, hence need antidependences
1292   // More specifically, needs_anti_dependence_check returns true iff the node
1293   // (a) does a load, and (b) does not perform a store (except perhaps to a
1294   // stack slot or some other unaliased location).
1295   bool needs_anti_dependence_check() const;
1296 
1297   // Return which operand this instruction may cisc-spill. In other words,
1298   // return operand position that can convert from reg to memory access
1299   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
1300   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
1301 
1302   // Whether this is a memory-writing machine node.
1303   bool is_memory_writer() const { return is_Mach() && bottom_type()->has_memory(); }
1304 
1305   // Whether this is a memory phi node
1306   bool is_memory_phi() const { return is_Phi() && bottom_type() == Type::MEMORY; }
1307 
1308   bool is_div_or_mod(BasicType bt) const;
1309 
1310   bool is_data_proj_of_pure_function(const Node* maybe_pure_function) const;
1311 
1312 //----------------- Printing, etc
1313 #ifndef PRODUCT
1314  public:
1315   Node* find(int idx, bool only_ctrl = false); // Search the graph for the given idx.
1316   Node* find_ctrl(int idx); // Search control ancestors for the given idx.
1317   void dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st, const frame* fr = nullptr) const;
1318   void dump_bfs(const int max_distance, Node* target, const char* options) const; // directly to tty
1319   void dump_bfs(const int max_distance) const; // dump_bfs(max_distance, nullptr, nullptr)
1320   void dump_bfs(const int max_distance, Node* target, const char* options, void* sp, void* fp, void* pc) const;
1321   class DumpConfig {
1322    public:
1323     // overridden to implement coloring of node idx
1324     virtual void pre_dump(outputStream *st, const Node* n) = 0;
1325     virtual void post_dump(outputStream *st) = 0;
1326   };
1327   void dump_idx(bool align = false, outputStream* st = tty, DumpConfig* dc = nullptr) const;
1328   void dump_name(outputStream* st = tty, DumpConfig* dc = nullptr) const;
1329   void dump() const; // print node with newline
1330   void dump(const char* suffix, bool mark = false, outputStream* st = tty, DumpConfig* dc = nullptr) const; // Print this node.
1331   void dump(int depth) const;        // Print this node, recursively to depth d
1332   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
1333   void dump_comp() const;            // Print this node in compact representation.
1334   // Print this node in compact representation.
1335   void dump_comp(const char* suffix, outputStream *st = tty) const;
1336  private:
1337   virtual void dump_req(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print required-edge info
1338   virtual void dump_prec(outputStream* st = tty, DumpConfig* dc = nullptr) const;   // Print precedence-edge info
1339   virtual void dump_out(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print the output edge info
1340  public:
1341   virtual void dump_spec(outputStream *st) const {};      // Print per-node info
1342   // Print compact per-node info
1343   virtual void dump_compact_spec(outputStream *st) const { dump_spec(st); }
1344 
1345   static void verify(int verify_depth, VectorSet& visited, Node_List& worklist);
1346 
1347   // This call defines a class-unique string used to identify class instances
1348   virtual const char *Name() const;
1349 
1350   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1351   static bool in_dump() { return Compile::current()->_in_dump_cnt > 0; } // check if we are in a dump call
1352 #endif
1353 #ifdef ASSERT
1354   void verify_construction();
1355   bool verify_jvms(const JVMState* jvms) const;
1356 
1357   Node* _debug_orig;                   // Original version of this, if any.
1358   Node*  debug_orig() const            { return _debug_orig; }
1359   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1360   void   dump_orig(outputStream *st, bool print_key = true) const;
1361 
1362   uint64_t _debug_idx;                 // Unique value assigned to every node.
1363   uint64_t debug_idx() const           { return _debug_idx; }
1364   void set_debug_idx(uint64_t debug_idx) { _debug_idx = debug_idx; }
1365 
1366   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1367   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1368   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1369 
1370   static void init_NodeProperty();
1371 
1372   #if OPTO_DU_ITERATOR_ASSERT
1373   const Node* _last_del;               // The last deleted node.
1374   uint        _del_tick;               // Bumped when a deletion happens..
1375   #endif
1376 #endif
1377 };
1378 
1379 inline bool not_a_node(const Node* n) {
1380   if (n == nullptr)                return true;
1381   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
1382   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
1383   return false;
1384 }
1385 
1386 //-----------------------------------------------------------------------------
1387 // Iterators over DU info, and associated Node functions.
1388 
1389 #if OPTO_DU_ITERATOR_ASSERT
1390 
1391 // Common code for assertion checking on DU iterators.
1392 class DUIterator_Common {
1393 #ifdef ASSERT
1394  protected:
1395   bool         _vdui;               // cached value of VerifyDUIterators
1396   const Node*  _node;               // the node containing the _out array
1397   uint         _outcnt;             // cached node->_outcnt
1398   uint         _del_tick;           // cached node->_del_tick
1399   Node*        _last;               // last value produced by the iterator
1400 
1401   void sample(const Node* node);    // used by c'tor to set up for verifies
1402   void verify(const Node* node, bool at_end_ok = false);
1403   void verify_resync();
1404   void reset(const DUIterator_Common& that);
1405 
1406 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1407   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1408 #else
1409   #define I_VDUI_ONLY(i,x) { }
1410 #endif //ASSERT
1411 };
1412 
1413 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1414 
1415 // Default DU iterator.  Allows appends onto the out array.
1416 // Allows deletion from the out array only at the current point.
1417 // Usage:
1418 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1419 //    Node* y = x->out(i);
1420 //    ...
1421 //  }
1422 // Compiles in product mode to a unsigned integer index, which indexes
1423 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1424 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1425 // before continuing the loop.  You must delete only the last-produced
1426 // edge.  You must delete only a single copy of the last-produced edge,
1427 // or else you must delete all copies at once (the first time the edge
1428 // is produced by the iterator).
1429 class DUIterator : public DUIterator_Common {
1430   friend class Node;
1431 
1432   // This is the index which provides the product-mode behavior.
1433   // Whatever the product-mode version of the system does to the
1434   // DUI index is done to this index.  All other fields in
1435   // this class are used only for assertion checking.
1436   uint         _idx;
1437 
1438   #ifdef ASSERT
1439   uint         _refresh_tick;    // Records the refresh activity.
1440 
1441   void sample(const Node* node); // Initialize _refresh_tick etc.
1442   void verify(const Node* node, bool at_end_ok = false);
1443   void verify_increment();       // Verify an increment operation.
1444   void verify_resync();          // Verify that we can back up over a deletion.
1445   void verify_finish();          // Verify that the loop terminated properly.
1446   void refresh();                // Resample verification info.
1447   void reset(const DUIterator& that);  // Resample after assignment.
1448   #endif
1449 
1450   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1451     { _idx = 0;                         DEBUG_ONLY(sample(node)); }
1452 
1453  public:
1454   // initialize to garbage; clear _vdui to disable asserts
1455   DUIterator()
1456     { /*initialize to garbage*/         DEBUG_ONLY(_vdui = false); }
1457 
1458   DUIterator(const DUIterator& that)
1459     { _idx = that._idx;                 DEBUG_ONLY(_vdui = false; reset(that)); }
1460 
1461   void operator++(int dummy_to_specify_postfix_op)
1462     { _idx++;                           VDUI_ONLY(verify_increment()); }
1463 
1464   void operator--()
1465     { VDUI_ONLY(verify_resync());       --_idx; }
1466 
1467   ~DUIterator()
1468     { VDUI_ONLY(verify_finish()); }
1469 
1470   void operator=(const DUIterator& that)
1471     { _idx = that._idx;                 DEBUG_ONLY(reset(that)); }
1472 };
1473 
1474 DUIterator Node::outs() const
1475   { return DUIterator(this, 0); }
1476 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1477   { I_VDUI_ONLY(i, i.refresh());        return i; }
1478 bool Node::has_out(DUIterator& i) const
1479   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1480 Node*    Node::out(DUIterator& i) const
1481   { I_VDUI_ONLY(i, i.verify(this));     return DEBUG_ONLY(i._last=) _out[i._idx]; }
1482 
1483 
1484 // Faster DU iterator.  Disallows insertions into the out array.
1485 // Allows deletion from the out array only at the current point.
1486 // Usage:
1487 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1488 //    Node* y = x->fast_out(i);
1489 //    ...
1490 //  }
1491 // Compiles in product mode to raw Node** pointer arithmetic, with
1492 // no reloading of pointers from the original node x.  If you delete,
1493 // you must perform "--i; --imax" just before continuing the loop.
1494 // If you delete multiple copies of the same edge, you must decrement
1495 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1496 class DUIterator_Fast : public DUIterator_Common {
1497   friend class Node;
1498   friend class DUIterator_Last;
1499 
1500   // This is the pointer which provides the product-mode behavior.
1501   // Whatever the product-mode version of the system does to the
1502   // DUI pointer is done to this pointer.  All other fields in
1503   // this class are used only for assertion checking.
1504   Node**       _outp;
1505 
1506   #ifdef ASSERT
1507   void verify(const Node* node, bool at_end_ok = false);
1508   void verify_limit();
1509   void verify_resync();
1510   void verify_relimit(uint n);
1511   void reset(const DUIterator_Fast& that);
1512   #endif
1513 
1514   // Note:  offset must be signed, since -1 is sometimes passed
1515   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1516     { _outp = node->_out + offset;      DEBUG_ONLY(sample(node)); }
1517 
1518  public:
1519   // initialize to garbage; clear _vdui to disable asserts
1520   DUIterator_Fast()
1521     { /*initialize to garbage*/         DEBUG_ONLY(_vdui = false); }
1522 
1523   DUIterator_Fast(const DUIterator_Fast& that)
1524     { _outp = that._outp;               DEBUG_ONLY(_vdui = false; reset(that)); }
1525 
1526   void operator++(int dummy_to_specify_postfix_op)
1527     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1528 
1529   void operator--()
1530     { VDUI_ONLY(verify_resync());       --_outp; }
1531 
1532   void operator-=(uint n)   // applied to the limit only
1533     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1534 
1535   bool operator<(DUIterator_Fast& limit) {
1536     I_VDUI_ONLY(*this, this->verify(_node, true));
1537     I_VDUI_ONLY(limit, limit.verify_limit());
1538     return _outp < limit._outp;
1539   }
1540 
1541   void operator=(const DUIterator_Fast& that)
1542     { _outp = that._outp;               DEBUG_ONLY(reset(that)); }
1543 };
1544 
1545 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1546   // Assign a limit pointer to the reference argument:
1547   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1548   // Return the base pointer:
1549   return DUIterator_Fast(this, 0);
1550 }
1551 Node* Node::fast_out(DUIterator_Fast& i) const {
1552   I_VDUI_ONLY(i, i.verify(this));
1553   return DEBUG_ONLY(i._last=) *i._outp;
1554 }
1555 
1556 
1557 // Faster DU iterator.  Requires each successive edge to be removed.
1558 // Does not allow insertion of any edges.
1559 // Usage:
1560 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1561 //    Node* y = x->last_out(i);
1562 //    ...
1563 //  }
1564 // Compiles in product mode to raw Node** pointer arithmetic, with
1565 // no reloading of pointers from the original node x.
1566 class DUIterator_Last : private DUIterator_Fast {
1567   friend class Node;
1568 
1569   #ifdef ASSERT
1570   void verify(const Node* node, bool at_end_ok = false);
1571   void verify_limit();
1572   void verify_step(uint num_edges);
1573   #endif
1574 
1575   // Note:  offset must be signed, since -1 is sometimes passed
1576   DUIterator_Last(const Node* node, ptrdiff_t offset)
1577     : DUIterator_Fast(node, offset) { }
1578 
1579   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1580   void operator<(int)                              {} // do not use
1581 
1582  public:
1583   DUIterator_Last() { }
1584   // initialize to garbage
1585 
1586   DUIterator_Last(const DUIterator_Last& that) = default;
1587 
1588   void operator--()
1589     { _outp--;              VDUI_ONLY(verify_step(1));  }
1590 
1591   void operator-=(uint n)
1592     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1593 
1594   bool operator>=(DUIterator_Last& limit) {
1595     I_VDUI_ONLY(*this, this->verify(_node, true));
1596     I_VDUI_ONLY(limit, limit.verify_limit());
1597     return _outp >= limit._outp;
1598   }
1599 
1600   DUIterator_Last& operator=(const DUIterator_Last& that) = default;
1601 };
1602 
1603 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1604   // Assign a limit pointer to the reference argument:
1605   imin = DUIterator_Last(this, 0);
1606   // Return the initial pointer:
1607   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1608 }
1609 Node* Node::last_out(DUIterator_Last& i) const {
1610   I_VDUI_ONLY(i, i.verify(this));
1611   return DEBUG_ONLY(i._last=) *i._outp;
1612 }
1613 
1614 #endif //OPTO_DU_ITERATOR_ASSERT
1615 
1616 #undef I_VDUI_ONLY
1617 #undef VDUI_ONLY
1618 
1619 // An Iterator that truly follows the iterator pattern.  Doesn't
1620 // support deletion but could be made to.
1621 //
1622 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1623 //     Node* m = i.get();
1624 //
1625 class SimpleDUIterator : public StackObj {
1626  private:
1627   Node* node;
1628   DUIterator_Fast imax;
1629   DUIterator_Fast i;
1630  public:
1631   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1632   bool has_next() { return i < imax; }
1633   void next() { i++; }
1634   Node* get() { return node->fast_out(i); }
1635 };
1636 
1637 
1638 //-----------------------------------------------------------------------------
1639 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1640 // Abstractly provides an infinite array of Node*'s, initialized to null.
1641 // Note that the constructor just zeros things, and since I use Arena
1642 // allocation I do not need a destructor to reclaim storage.
1643 class Node_Array : public AnyObj {
1644 protected:
1645   Arena* _a;                    // Arena to allocate in
1646   uint   _max;
1647   Node** _nodes;
1648   ReallocMark _nesting;         // Safety checks for arena reallocation
1649 
1650   // Grow array to required capacity
1651   void maybe_grow(uint i) {
1652     _nesting.check(_a); // Check if a potential reallocation in the arena is safe
1653     if (i >= _max) {
1654       grow(i);
1655     }
1656   }
1657   void grow(uint i);
1658 
1659 public:
1660   Node_Array(Arena* a, uint max = OptoNodeListSize) : _a(a), _max(max) {
1661     _nodes = NEW_ARENA_ARRAY(a, Node*, max);
1662     clear();
1663   }
1664   Node_Array() : Node_Array(Thread::current()->resource_area()) {}
1665 
1666   NONCOPYABLE(Node_Array);
1667   Node_Array& operator=(Node_Array&&) = delete;
1668   // Allow move constructor for && (eg. capture return of function)
1669   Node_Array(Node_Array&&) = default;
1670 
1671   Node *operator[] ( uint i ) const // Lookup, or null for not mapped
1672   { return (i<_max) ? _nodes[i] : (Node*)nullptr; }
1673   Node* at(uint i) const { assert(i<_max,"oob"); return _nodes[i]; }
1674   Node** adr() { return _nodes; }
1675   // Extend the mapping: index i maps to Node *n.
1676   void map( uint i, Node *n ) { maybe_grow(i); _nodes[i] = n; }
1677   void insert( uint i, Node *n );
1678   void remove( uint i );        // Remove, preserving order
1679   // Clear all entries in _nodes to null but keep storage
1680   void clear() {
1681     Copy::zero_to_bytes(_nodes, _max * sizeof(Node*));
1682   }
1683 
1684   uint max() const { return _max; }
1685   void dump() const;
1686 };
1687 
1688 class Node_List : public Node_Array {
1689   uint _cnt;
1690 public:
1691   Node_List(uint max = OptoNodeListSize) : Node_Array(Thread::current()->resource_area(), max), _cnt(0) {}
1692   Node_List(Arena *a, uint max = OptoNodeListSize) : Node_Array(a, max), _cnt(0) {}
1693 
1694   NONCOPYABLE(Node_List);
1695   Node_List& operator=(Node_List&&) = delete;
1696   // Allow move constructor for && (eg. capture return of function)
1697   Node_List(Node_List&&) = default;
1698 
1699   bool contains(const Node* n) const {
1700     for (uint e = 0; e < size(); e++) {
1701       if (at(e) == n) return true;
1702     }
1703     return false;
1704   }
1705   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1706   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1707   void push( Node *b ) { map(_cnt++,b); }
1708   void yank( Node *n );         // Find and remove
1709   Node *pop() { return _nodes[--_cnt]; }
1710   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1711   void copy(const Node_List& from) {
1712     if (from._max > _max) {
1713       grow(from._max);
1714     }
1715     _cnt = from._cnt;
1716     Copy::conjoint_words_to_higher((HeapWord*)&from._nodes[0], (HeapWord*)&_nodes[0], from._max * sizeof(Node*));
1717   }
1718 
1719   uint size() const { return _cnt; }
1720   void dump() const;
1721   void dump_simple() const;
1722 };
1723 
1724 // Definition must appear after complete type definition of Node_List
1725 template <typename Callback, typename Check>
1726 void Node::visit_uses(Callback callback, Check is_boundary) const {
1727   ResourceMark rm;
1728   VectorSet visited;
1729   Node_List worklist;
1730 
1731   // The initial worklist consists of the direct uses
1732   for (DUIterator_Fast kmax, k = fast_outs(kmax); k < kmax; k++) {
1733     Node* out = fast_out(k);
1734     if (!visited.test_set(out->_idx)) { worklist.push(out); }
1735   }
1736 
1737   while (worklist.size() > 0) {
1738     Node* use = worklist.pop();
1739     // Apply callback on boundary nodes
1740     if (is_boundary(use)) {
1741       callback(use);
1742     } else {
1743       // Not a boundary node, continue search
1744       for (DUIterator_Fast kmax, k = use->fast_outs(kmax); k < kmax; k++) {
1745         Node* out = use->fast_out(k);
1746         if (!visited.test_set(out->_idx)) { worklist.push(out); }
1747       }
1748     }
1749   }
1750 }
1751 
1752 
1753 //------------------------------Unique_Node_List-------------------------------
1754 class Unique_Node_List : public Node_List {
1755   VectorSet _in_worklist;
1756   uint _clock_index;            // Index in list where to pop from next
1757 public:
1758   Unique_Node_List() : Node_List(), _clock_index(0) {}
1759   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1760 
1761   NONCOPYABLE(Unique_Node_List);
1762   Unique_Node_List& operator=(Unique_Node_List&&) = delete;
1763   // Allow move constructor for && (eg. capture return of function)
1764   Unique_Node_List(Unique_Node_List&&) = default;
1765 
1766   void remove( Node *n );
1767   bool member(const Node* n) const { return _in_worklist.test(n->_idx) != 0; }
1768   VectorSet& member_set(){ return _in_worklist; }
1769 
1770   void push(Node* b) {
1771     if( !_in_worklist.test_set(b->_idx) )
1772       Node_List::push(b);
1773   }
1774   void push_non_cfg_inputs_of(const Node* node) {
1775     for (uint i = 1; i < node->req(); i++) {
1776       Node* input = node->in(i);
1777       if (input != nullptr && !input->is_CFG()) {
1778         push(input);
1779       }
1780     }
1781   }
1782 
1783   void push_outputs_of(const Node* node) {
1784     for (DUIterator_Fast imax, i = node->fast_outs(imax); i < imax; i++) {
1785       Node* output = node->fast_out(i);
1786       push(output);
1787     }
1788   }
1789 
1790   Node *pop() {
1791     if( _clock_index >= size() ) _clock_index = 0;
1792     Node *b = at(_clock_index);
1793     map( _clock_index, Node_List::pop());
1794     if (size() != 0) _clock_index++; // Always start from 0
1795     _in_worklist.remove(b->_idx);
1796     return b;
1797   }
1798   Node *remove(uint i) {
1799     Node *b = Node_List::at(i);
1800     _in_worklist.remove(b->_idx);
1801     map(i,Node_List::pop());
1802     return b;
1803   }
1804   void yank(Node *n) {
1805     _in_worklist.remove(n->_idx);
1806     Node_List::yank(n);
1807   }
1808   void  clear() {
1809     _in_worklist.clear();        // Discards storage but grows automatically
1810     Node_List::clear();
1811     _clock_index = 0;
1812   }
1813   void ensure_empty() {
1814     assert(size() == 0, "must be empty");
1815     clear(); // just in case
1816   }
1817 
1818   // Used after parsing to remove useless nodes before Iterative GVN
1819   void remove_useless_nodes(VectorSet& useful);
1820 
1821   // If the idx of the Nodes change, we must recompute the VectorSet
1822   void recompute_idx_set() {
1823     _in_worklist.clear();
1824     for (uint i = 0; i < size(); i++) {
1825       Node* n = at(i);
1826       _in_worklist.set(n->_idx);
1827     }
1828   }
1829 
1830 #ifdef ASSERT
1831   bool is_subset_of(Unique_Node_List& other) {
1832     for (uint i = 0; i < size(); i++) {
1833       Node* n = at(i);
1834       if (!other.member(n)) {
1835         return false;
1836       }
1837     }
1838     return true;
1839   }
1840 #endif
1841 
1842   bool contains(const Node* n) const {
1843     fatal("use faster member() instead");
1844     return false;
1845   }
1846 
1847 #ifndef PRODUCT
1848   void print_set() const { _in_worklist.print(); }
1849 #endif
1850 };
1851 
1852 // Unique_Mixed_Node_List
1853 // unique: nodes are added only once
1854 // mixed: allow new and old nodes
1855 class Unique_Mixed_Node_List : public ResourceObj {
1856 public:
1857   Unique_Mixed_Node_List() : _visited_set(cmpkey, hashkey) {}
1858 
1859   void add(Node* node) {
1860     if (not_a_node(node)) {
1861       return; // Gracefully handle null, -1, 0xabababab, etc.
1862     }
1863     if (_visited_set[node] == nullptr) {
1864       _visited_set.Insert(node, node);
1865       _worklist.push(node);
1866     }
1867   }
1868 
1869   Node* operator[] (uint i) const {
1870     return _worklist[i];
1871   }
1872 
1873   size_t size() {
1874     return _worklist.size();
1875   }
1876 
1877 private:
1878   Dict _visited_set;
1879   Node_List _worklist;
1880 };
1881 
1882 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1883 inline void Compile::record_for_igvn(Node* n) {
1884   _igvn_worklist->push(n);
1885 }
1886 
1887 // Inline definition of Compile::remove_for_igvn must be deferred to this point.
1888 inline void Compile::remove_for_igvn(Node* n) {
1889   _igvn_worklist->remove(n);
1890 }
1891 
1892 //------------------------------Node_Stack-------------------------------------
1893 class Node_Stack {
1894 protected:
1895   struct INode {
1896     Node *node; // Processed node
1897     uint  indx; // Index of next node's child
1898   };
1899   INode *_inode_top; // tos, stack grows up
1900   INode *_inode_max; // End of _inodes == _inodes + _max
1901   INode *_inodes;    // Array storage for the stack
1902   Arena *_a;         // Arena to allocate in
1903   ReallocMark _nesting; // Safety checks for arena reallocation
1904 
1905   void maybe_grow() {
1906     _nesting.check(_a); // Check if a potential reallocation in the arena is safe
1907     if (_inode_top >= _inode_max) {
1908       grow();
1909     }
1910   }
1911   void grow();
1912 
1913 public:
1914   Node_Stack(int size) {
1915     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1916     _a = Thread::current()->resource_area();
1917     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1918     _inode_max = _inodes + max;
1919     _inode_top = _inodes - 1; // stack is empty
1920   }
1921 
1922   Node_Stack(Arena *a, int size) : _a(a) {
1923     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1924     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1925     _inode_max = _inodes + max;
1926     _inode_top = _inodes - 1; // stack is empty
1927   }
1928 
1929   void pop() {
1930     assert(_inode_top >= _inodes, "node stack underflow");
1931     --_inode_top;
1932   }
1933   void push(Node *n, uint i) {
1934     ++_inode_top;
1935     maybe_grow();
1936     INode *top = _inode_top; // optimization
1937     top->node = n;
1938     top->indx = i;
1939   }
1940   Node *node() const {
1941     return _inode_top->node;
1942   }
1943   Node* node_at(uint i) const {
1944     assert(_inodes + i <= _inode_top, "in range");
1945     return _inodes[i].node;
1946   }
1947   uint index() const {
1948     return _inode_top->indx;
1949   }
1950   uint index_at(uint i) const {
1951     assert(_inodes + i <= _inode_top, "in range");
1952     return _inodes[i].indx;
1953   }
1954   void set_node(Node *n) {
1955     _inode_top->node = n;
1956   }
1957   void set_index(uint i) {
1958     _inode_top->indx = i;
1959   }
1960   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1961   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1962   bool is_nonempty() const { return (_inode_top >= _inodes); }
1963   bool is_empty() const { return (_inode_top < _inodes); }
1964   void clear() { _inode_top = _inodes - 1; } // retain storage
1965 
1966   // Node_Stack is used to map nodes.
1967   Node* find(uint idx) const;
1968 
1969   NONCOPYABLE(Node_Stack);
1970 };
1971 
1972 
1973 //-----------------------------Node_Notes--------------------------------------
1974 // Debugging or profiling annotations loosely and sparsely associated
1975 // with some nodes.  See Compile::node_notes_at for the accessor.
1976 class Node_Notes {
1977   JVMState* _jvms;
1978 
1979 public:
1980   Node_Notes(JVMState* jvms = nullptr) {
1981     _jvms = jvms;
1982   }
1983 
1984   JVMState* jvms()            { return _jvms; }
1985   void  set_jvms(JVMState* x) {        _jvms = x; }
1986 
1987   // True if there is nothing here.
1988   bool is_clear() {
1989     return (_jvms == nullptr);
1990   }
1991 
1992   // Make there be nothing here.
1993   void clear() {
1994     _jvms = nullptr;
1995   }
1996 
1997   // Make a new, clean node notes.
1998   static Node_Notes* make(Compile* C) {
1999     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
2000     nn->clear();
2001     return nn;
2002   }
2003 
2004   Node_Notes* clone(Compile* C) {
2005     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
2006     (*nn) = (*this);
2007     return nn;
2008   }
2009 
2010   // Absorb any information from source.
2011   bool update_from(Node_Notes* source) {
2012     bool changed = false;
2013     if (source != nullptr) {
2014       if (source->jvms() != nullptr) {
2015         set_jvms(source->jvms());
2016         changed = true;
2017       }
2018     }
2019     return changed;
2020   }
2021 };
2022 
2023 // Inlined accessors for Compile::node_nodes that require the preceding class:
2024 inline Node_Notes*
2025 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
2026                            int idx, bool can_grow) {
2027   assert(idx >= 0, "oob");
2028   int block_idx = (idx >> _log2_node_notes_block_size);
2029   int grow_by = (block_idx - (arr == nullptr? 0: arr->length()));
2030   if (grow_by >= 0) {
2031     if (!can_grow) return nullptr;
2032     grow_node_notes(arr, grow_by + 1);
2033   }
2034   if (arr == nullptr) return nullptr;
2035   // (Every element of arr is a sub-array of length _node_notes_block_size.)
2036   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
2037 }
2038 
2039 inline Node_Notes* Compile::node_notes_at(int idx) {
2040   return locate_node_notes(_node_note_array, idx, false);
2041 }
2042 
2043 inline bool
2044 Compile::set_node_notes_at(int idx, Node_Notes* value) {
2045   if (value == nullptr || value->is_clear())
2046     return false;  // nothing to write => write nothing
2047   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
2048   assert(loc != nullptr, "");
2049   return loc->update_from(value);
2050 }
2051 
2052 
2053 //------------------------------TypeNode---------------------------------------
2054 // Node with a Type constant.
2055 class TypeNode : public Node {
2056 protected:
2057   virtual uint hash() const;    // Check the type
2058   virtual bool cmp( const Node &n ) const;
2059   virtual uint size_of() const; // Size is bigger
2060   const Type* const _type;
2061 public:
2062   void set_type(const Type* t) {
2063     assert(t != nullptr, "sanity");
2064     DEBUG_ONLY(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
2065     *(const Type**)&_type = t;   // cast away const-ness
2066     // If this node is in the hash table, make sure it doesn't need a rehash.
2067     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
2068   }
2069   const Type* type() const { assert(_type != nullptr, "sanity"); return _type; };
2070   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
2071     init_class_id(Class_Type);
2072   }
2073   virtual const Type* Value(PhaseGVN* phase) const;
2074   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
2075   virtual const Type *bottom_type() const;
2076   virtual       uint  ideal_reg() const;
2077 
2078   void make_path_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, Node* ctrl_use, uint j, const char* phase_str);
2079 #ifndef PRODUCT
2080   virtual void dump_spec(outputStream *st) const;
2081   virtual void dump_compact_spec(outputStream *st) const;
2082 #endif
2083   void make_paths_from_here_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, const char* phase_str);
2084   void create_halt_path(PhaseIterGVN* igvn, Node* c, PhaseIdealLoop* loop, const char* phase_str) const;
2085 };
2086 
2087 #include "opto/opcodes.hpp"
2088 
2089 #define Op_IL(op) \
2090   inline int Op_ ## op(BasicType bt) { \
2091   assert(bt == T_INT || bt == T_LONG, "only for int or longs"); \
2092   if (bt == T_INT) { \
2093     return Op_## op ## I; \
2094   } \
2095   return Op_## op ## L; \
2096 }
2097 
2098 Op_IL(Add)
2099 Op_IL(And)
2100 Op_IL(Sub)
2101 Op_IL(Mul)
2102 Op_IL(URShift)
2103 Op_IL(LShift)
2104 Op_IL(RShift)
2105 Op_IL(Xor)
2106 Op_IL(Cmp)
2107 Op_IL(Div)
2108 Op_IL(Mod)
2109 Op_IL(UDiv)
2110 Op_IL(UMod)
2111 
2112 inline int Op_ConIL(BasicType bt) {
2113   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2114   if (bt == T_INT) {
2115     return Op_ConI;
2116   }
2117   return Op_ConL;
2118 }
2119 
2120 inline int Op_Cmp_unsigned(BasicType bt) {
2121   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2122   if (bt == T_INT) {
2123     return Op_CmpU;
2124   }
2125   return Op_CmpUL;
2126 }
2127 
2128 inline int Op_Cast(BasicType bt) {
2129   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2130   if (bt == T_INT) {
2131     return Op_CastII;
2132   }
2133   return Op_CastLL;
2134 }
2135 
2136 inline int Op_DivIL(BasicType bt, bool is_unsigned) {
2137   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2138   if (bt == T_INT) {
2139     if (is_unsigned) {
2140       return Op_UDivI;
2141     } else {
2142       return Op_DivI;
2143     }
2144   }
2145   if (is_unsigned) {
2146     return Op_UDivL;
2147   } else {
2148     return Op_DivL;
2149   }
2150 }
2151 
2152 inline int Op_DivModIL(BasicType bt, bool is_unsigned) {
2153   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2154   if (bt == T_INT) {
2155     if (is_unsigned) {
2156       return Op_UDivModI;
2157     } else {
2158       return Op_DivModI;
2159     }
2160   }
2161   if (is_unsigned) {
2162     return Op_UDivModL;
2163   } else {
2164     return Op_DivModL;
2165   }
2166 }
2167 
2168 // Interface to define actions that should be taken when running DataNodeBFS. Each use can extend this class to specify
2169 // a customized BFS.
2170 class BFSActions : public StackObj {
2171  public:
2172   // Should a node's inputs further be visited in the BFS traversal? By default, we visit all data inputs. Override this
2173   // method to provide a custom filter.
2174   virtual bool should_visit(Node* node) const {
2175     // By default, visit all inputs.
2176     return true;
2177   };
2178 
2179   // Is the visited node a target node that we are looking for in the BFS traversal? We do not visit its inputs further
2180   // but the BFS will continue to visit all unvisited nodes in the queue.
2181   virtual bool is_target_node(Node* node) const = 0;
2182 
2183   // Defines an action that should be taken when we visit a target node in the BFS traversal.
2184   // To give more freedom, we pass the direct child node to the target node such that
2185   // child->in(i) == target node. This allows to also directly replace the target node instead
2186   // of only updating its inputs.
2187   virtual void target_node_action(Node* child, uint i) = 0;
2188 };
2189 
2190 // Class to perform a BFS traversal on the data nodes from a given start node. The provided BFSActions guide which
2191 // data node's inputs should be further visited, which data nodes are target nodes and what to do with the target nodes.
2192 class DataNodeBFS : public StackObj {
2193   BFSActions& _bfs_actions;
2194 
2195  public:
2196   explicit DataNodeBFS(BFSActions& bfs_action) : _bfs_actions(bfs_action) {}
2197 
2198   // Run the BFS starting from 'start_node' and apply the actions provided to this class.
2199   void run(Node* start_node) {
2200     ResourceMark rm;
2201     Unique_Node_List _nodes_to_visit;
2202     _nodes_to_visit.push(start_node);
2203     for (uint i = 0; i < _nodes_to_visit.size(); i++) {
2204       Node* next = _nodes_to_visit[i];
2205       for (uint j = 1; j < next->req(); j++) {
2206         Node* input = next->in(j);
2207         if (_bfs_actions.is_target_node(input)) {
2208           assert(_bfs_actions.should_visit(input), "must also pass node filter");
2209           _bfs_actions.target_node_action(next, j);
2210         } else if (_bfs_actions.should_visit(input)) {
2211           _nodes_to_visit.push(input);
2212         }
2213       }
2214     }
2215   }
2216 };
2217 
2218 #endif // SHARE_OPTO_NODE_HPP