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 FlatArrayCheckNode;
  91 class HaltNode;
  92 class IfNode;
  93 class IfProjNode;
  94 class IfFalseNode;
  95 class IfTrueNode;
  96 class InitializeNode;
  97 class JVMState;
  98 class JumpNode;
  99 class JumpProjNode;
 100 class LoadNode;
 101 class LoadStoreNode;
 102 class LoadStoreConditionalNode;
 103 class LockNode;
 104 class LongCountedLoopNode;
 105 class LongCountedLoopEndNode;
 106 class LoopNode;
 107 class LShiftNode;
 108 class MachBranchNode;
 109 class MachCallDynamicJavaNode;
 110 class MachCallJavaNode;
 111 class MachCallLeafNode;
 112 class MachCallNode;
 113 class MachCallRuntimeNode;
 114 class MachCallStaticJavaNode;
 115 class MachConstantBaseNode;
 116 class MachConstantNode;
 117 class MachGotoNode;
 118 class MachIfNode;
 119 class MachJumpNode;
 120 class MachNode;
 121 class MachNullCheckNode;
 122 class MachProjNode;
 123 class MachPrologNode;
 124 class MachReturnNode;
 125 class MachSafePointNode;
 126 class MachSpillCopyNode;
 127 class MachTempNode;
 128 class MachMergeNode;
 129 class MachMemBarNode;
 130 class MachVEPNode;
 131 class Matcher;
 132 class MemBarNode;
 133 class MemBarStoreStoreNode;
 134 class MemNode;
 135 class MergeMemNode;
 136 class MinMaxNode;
 137 class MoveNode;
 138 class MulNode;
 139 class MultiNode;
 140 class MultiBranchNode;
 141 class NarrowMemProjNode;
 142 class NegNode;
 143 class NegVNode;
 144 class NeverBranchNode;
 145 class Opaque1Node;
 146 class OpaqueLoopInitNode;
 147 class OpaqueLoopStrideNode;
 148 class OpaqueMultiversioningNode;
 149 class OpaqueNotNullNode;
 150 class OpaqueInitializedAssertionPredicateNode;
 151 class OpaqueTemplateAssertionPredicateNode;
 152 class OuterStripMinedLoopNode;
 153 class OuterStripMinedLoopEndNode;
 154 class Node;
 155 class Node_Array;
 156 class Node_List;
 157 class Node_Stack;
 158 class OopMap;
 159 class ParmNode;
 160 class ParsePredicateNode;
 161 class PCTableNode;
 162 class PhaseCCP;
 163 class PhaseGVN;
 164 class PhaseIdealLoop;
 165 class PhaseIterGVN;
 166 class PhaseRegAlloc;
 167 class PhaseTransform;
 168 class PhaseValues;
 169 class PhiNode;
 170 class Pipeline;
 171 class PopulateIndexNode;
 172 class ProjNode;
 173 class RangeCheckNode;
 174 class ReductionNode;
 175 class RegMask;
 176 class RegionNode;
 177 class RootNode;
 178 class SafePointNode;
 179 class SafePointScalarObjectNode;
 180 class SafePointScalarMergeNode;
 181 class SaturatingVectorNode;
 182 class StartNode;
 183 class State;
 184 class StoreNode;
 185 class SubNode;
 186 class SubTypeCheckNode;
 187 class Type;
 188 class TypeNode;
 189 class UnlockNode;
 190 class InlineTypeNode;
 191 class LoadFlatNode;
 192 class StoreFlatNode;
 193 class VectorNode;
 194 class LoadVectorNode;
 195 class LoadVectorMaskedNode;
 196 class StoreVectorMaskedNode;
 197 class LoadVectorGatherNode;
 198 class LoadVectorGatherMaskedNode;
 199 class StoreVectorNode;
 200 class StoreVectorScatterNode;
 201 class StoreVectorScatterMaskedNode;
 202 class VerifyVectorAlignmentNode;
 203 class VectorMaskCmpNode;
 204 class VectorUnboxNode;
 205 class VectorSet;
 206 class VectorReinterpretNode;
 207 class ShiftVNode;
 208 class MulVLNode;
 209 class ExpandVNode;
 210 class CompressVNode;
 211 class CompressMNode;
 212 class C2_MacroAssembler;
 213 
 214 
 215 #ifndef OPTO_DU_ITERATOR_ASSERT
 216 #ifdef ASSERT
 217 #define OPTO_DU_ITERATOR_ASSERT 1
 218 #else
 219 #define OPTO_DU_ITERATOR_ASSERT 0
 220 #endif
 221 #endif //OPTO_DU_ITERATOR_ASSERT
 222 
 223 #if OPTO_DU_ITERATOR_ASSERT
 224 class DUIterator;
 225 class DUIterator_Fast;
 226 class DUIterator_Last;
 227 #else
 228 typedef uint   DUIterator;
 229 typedef Node** DUIterator_Fast;
 230 typedef Node** DUIterator_Last;
 231 #endif
 232 
 233 typedef ResizeableHashTable<Node*, Node*, AnyObj::RESOURCE_AREA, mtCompiler> OrigToNewHashtable;
 234 
 235 // Node Sentinel
 236 #define NodeSentinel (Node*)-1
 237 
 238 // Unknown count frequency
 239 #define COUNT_UNKNOWN (-1.0f)
 240 
 241 //------------------------------Node-------------------------------------------
 242 // Nodes define actions in the program.  They create values, which have types.
 243 // They are both vertices in a directed graph and program primitives.  Nodes
 244 // are labeled; the label is the "opcode", the primitive function in the lambda
 245 // calculus sense that gives meaning to the Node.  Node inputs are ordered (so
 246 // that "a-b" is different from "b-a").  The inputs to a Node are the inputs to
 247 // the Node's function.  These inputs also define a Type equation for the Node.
 248 // Solving these Type equations amounts to doing dataflow analysis.
 249 // Control and data are uniformly represented in the graph.  Finally, Nodes
 250 // have a unique dense integer index which is used to index into side arrays
 251 // whenever I have phase-specific information.
 252 
 253 class Node {
 254 
 255   // Lots of restrictions on cloning Nodes
 256   NONCOPYABLE(Node);
 257 
 258 public:
 259   friend class Compile;
 260   #if OPTO_DU_ITERATOR_ASSERT
 261   friend class DUIterator_Common;
 262   friend class DUIterator;
 263   friend class DUIterator_Fast;
 264   friend class DUIterator_Last;
 265   #endif
 266 
 267   // Because Nodes come and go, I define an Arena of Node structures to pull
 268   // from.  This should allow fast access to node creation & deletion.  This
 269   // field is a local cache of a value defined in some "program fragment" for
 270   // which these Nodes are just a part of.
 271 
 272   inline void* operator new(size_t x) throw() {
 273     Compile* C = Compile::current();
 274     Node* n = (Node*)C->node_arena()->AmallocWords(x);
 275     return (void*)n;
 276   }
 277 
 278   // Delete is a NOP
 279   void operator delete( void *ptr ) {}
 280   // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
 281   void destruct(PhaseValues* phase);
 282 
 283   // Create a new Node.  Required is the number is of inputs required for
 284   // semantic correctness.
 285   Node( uint required );
 286 
 287   // Create a new Node with given input edges.
 288   // This version requires use of the "edge-count" new.
 289   // E.g.  new (C,3) FooNode( C, nullptr, left, right );
 290   Node( Node *n0 );
 291   Node( Node *n0, Node *n1 );
 292   Node( Node *n0, Node *n1, Node *n2 );
 293   Node( Node *n0, Node *n1, Node *n2, Node *n3 );
 294   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4 );
 295   Node( Node *n0, Node *n1, Node *n2, Node *n3, Node *n4, Node *n5 );
 296   Node( Node *n0, Node *n1, Node *n2, Node *n3,
 297             Node *n4, Node *n5, Node *n6 );
 298 
 299   // Clone an inherited Node given only the base Node type.
 300   Node* clone() const;
 301 
 302   // Clone a Node, immediately supplying one or two new edges.
 303   // The first and second arguments, if non-null, replace in(1) and in(2),
 304   // respectively.
 305   Node* clone_with_data_edge(Node* in1, Node* in2 = nullptr) const {
 306     Node* nn = clone();
 307     if (in1 != nullptr)  nn->set_req(1, in1);
 308     if (in2 != nullptr)  nn->set_req(2, in2);
 309     return nn;
 310   }
 311 
 312 private:
 313   // Shared setup for the above constructors.
 314   // Handles all interactions with Compile::current.
 315   // Puts initial values in all Node fields except _idx.
 316   // Returns the initial value for _idx, which cannot
 317   // be initialized by assignment.
 318   inline int Init(int req);
 319 
 320 //----------------- input edge handling
 321 protected:
 322   friend class PhaseCFG;        // Access to address of _in array elements
 323   Node **_in;                   // Array of use-def references to Nodes
 324   Node **_out;                  // Array of def-use references to Nodes
 325 
 326   // Input edges are split into two categories.  Required edges are required
 327   // for semantic correctness; order is important and nulls are allowed.
 328   // Precedence edges are used to help determine execution order and are
 329   // added, e.g., for scheduling purposes.  They are unordered and not
 330   // duplicated; they have no embedded nulls.  Edges from 0 to _cnt-1
 331   // are required, from _cnt to _max-1 are precedence edges.
 332   node_idx_t _cnt;              // Total number of required Node inputs.
 333 
 334   node_idx_t _max;              // Actual length of input array.
 335 
 336   // Output edges are an unordered list of def-use edges which exactly
 337   // correspond to required input edges which point from other nodes
 338   // to this one.  Thus the count of the output edges is the number of
 339   // users of this node.
 340   node_idx_t _outcnt;           // Total number of Node outputs.
 341 
 342   node_idx_t _outmax;           // Actual length of output array.
 343 
 344   // Grow the actual input array to the next larger power-of-2 bigger than len.
 345   void grow( uint len );
 346   // Grow the output array to the next larger power-of-2 bigger than len.
 347   void out_grow( uint len );
 348   // Resize input or output array to grow it to the next larger power-of-2
 349   // bigger than len.
 350   void resize_array(Node**& array, node_idx_t& max_size, uint len, bool needs_clearing);
 351 
 352 public:
 353   // Each Node is assigned a unique small/dense number. This number is used
 354   // to index into auxiliary arrays of data and bit vectors.
 355   // The value of _idx can be changed using the set_idx() method.
 356   //
 357   // The PhaseRenumberLive phase renumbers nodes based on liveness information.
 358   // Therefore, it updates the value of the _idx field. The parse-time _idx is
 359   // preserved in _parse_idx.
 360   node_idx_t _idx;
 361   DEBUG_ONLY(const node_idx_t _parse_idx;)
 362   // IGV node identifier. Two nodes, possibly in different compilation phases,
 363   // have the same IGV identifier if (and only if) they are the very same node
 364   // (same memory address) or one is "derived" from the other (by e.g.
 365   // renumbering or matching). This identifier makes it possible to follow the
 366   // entire lifetime of a node in IGV even if its C2 identifier (_idx) changes.
 367   NOT_PRODUCT(node_idx_t _igv_idx;)
 368 
 369   // Get the (read-only) number of input edges
 370   uint req() const { return _cnt; }
 371   uint len() const { return _max; }
 372   // Get the (read-only) number of output edges
 373   uint outcnt() const { return _outcnt; }
 374 
 375 #if OPTO_DU_ITERATOR_ASSERT
 376   // Iterate over the out-edges of this node.  Deletions are illegal.
 377   inline DUIterator outs() const;
 378   // Use this when the out array might have changed to suppress asserts.
 379   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 380   // Does the node have an out at this position?  (Used for iteration.)
 381   inline bool has_out(DUIterator& i) const;
 382   inline Node*    out(DUIterator& i) const;
 383   // Iterate over the out-edges of this node.  All changes are illegal.
 384   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 385   inline Node*    fast_out(DUIterator_Fast& i) const;
 386   // Iterate over the out-edges of this node, deleting one at a time.
 387   inline DUIterator_Last last_outs(DUIterator_Last& min) const;
 388   inline Node*    last_out(DUIterator_Last& i) const;
 389   // The inline bodies of all these methods are after the iterator definitions.
 390 #else
 391   // Iterate over the out-edges of this node.  Deletions are illegal.
 392   // This iteration uses integral indexes, to decouple from array reallocations.
 393   DUIterator outs() const  { return 0; }
 394   // Use this when the out array might have changed to suppress asserts.
 395   DUIterator refresh_out_pos(DUIterator i) const { return i; }
 396 
 397   // Reference to the i'th output Node.  Error if out of bounds.
 398   Node*    out(DUIterator i) const { assert(i < _outcnt, "oob"); return _out[i]; }
 399   // Does the node have an out at this position?  (Used for iteration.)
 400   bool has_out(DUIterator i) const { return i < _outcnt; }
 401 
 402   // Iterate over the out-edges of this node.  All changes are illegal.
 403   // This iteration uses a pointer internal to the out array.
 404   DUIterator_Fast fast_outs(DUIterator_Fast& max) const {
 405     Node** out = _out;
 406     // Assign a limit pointer to the reference argument:
 407     max = out + (ptrdiff_t)_outcnt;
 408     // Return the base pointer:
 409     return out;
 410   }
 411   Node*    fast_out(DUIterator_Fast i) const  { return *i; }
 412   // Iterate over the out-edges of this node, deleting one at a time.
 413   // This iteration uses a pointer internal to the out array.
 414   DUIterator_Last last_outs(DUIterator_Last& min) const {
 415     Node** out = _out;
 416     // Assign a limit pointer to the reference argument:
 417     min = out;
 418     // Return the pointer to the start of the iteration:
 419     return out + (ptrdiff_t)_outcnt - 1;
 420   }
 421   Node*    last_out(DUIterator_Last i) const  { return *i; }
 422 #endif
 423 
 424   // Reference to the i'th input Node.  Error if out of bounds.
 425   Node* in(uint i) const { assert(i < _max, "oob: i=%d, _max=%d", i, _max); return _in[i]; }
 426   // Reference to the i'th input Node.  null if out of bounds.
 427   Node* lookup(uint i) const { return ((i < _max) ? _in[i] : nullptr); }
 428   // Reference to the i'th output Node.  Error if out of bounds.
 429   // Use this accessor sparingly.  We are going trying to use iterators instead.
 430   Node* raw_out(uint i) const { assert(i < _outcnt,"oob"); return _out[i]; }
 431   // Return the unique out edge.
 432   Node* unique_out() const { assert(_outcnt==1,"not unique"); return _out[0]; }
 433 
 434   // In some cases, a node n is only used by a single use, but the use may use
 435   // n once or multiple times:
 436   //   use = ConvF2I(this)
 437   //   use = AddI(this, this)
 438   Node* unique_multiple_edges_out_or_null() const;
 439 
 440   // Delete out edge at position 'i' by moving last out edge to position 'i'
 441   void  raw_del_out(uint i) {
 442     assert(i < _outcnt,"oob");
 443     assert(_outcnt > 0,"oob");
 444     #if OPTO_DU_ITERATOR_ASSERT
 445     // Record that a change happened here.
 446     DEBUG_ONLY(_last_del = _out[i]; ++_del_tick);
 447     #endif
 448     _out[i] = _out[--_outcnt];
 449     // Smash the old edge so it can't be used accidentally.
 450     DEBUG_ONLY(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 451   }
 452 
 453 #ifdef ASSERT
 454   bool is_dead() const;
 455   static bool is_not_dead(const Node* n);
 456   bool is_reachable_from_root() const;
 457 #endif
 458   // Check whether node has become unreachable
 459   bool is_unreachable(PhaseIterGVN &igvn) const;
 460 
 461   // Set a required input edge, also updates corresponding output edge
 462   void add_req( Node *n ); // Append a NEW required input
 463   void add_req( Node *n0, Node *n1 ) {
 464     add_req(n0); add_req(n1); }
 465   void add_req( Node *n0, Node *n1, Node *n2 ) {
 466     add_req(n0); add_req(n1); add_req(n2); }
 467   void add_req_batch( Node* n, uint m ); // Append m NEW required inputs (all n).
 468   void del_req( uint idx ); // Delete required edge & compact
 469   void del_req_ordered( uint idx ); // Delete required edge & compact with preserved order
 470   void ins_req( uint i, Node *n ); // Insert a NEW required input
 471   void set_req( uint i, Node *n ) {
 472     assert( is_not_dead(n), "can not use dead node");
 473     assert( i < _cnt, "oob: i=%d, _cnt=%d", i, _cnt);
 474     assert( !VerifyHashTableKeys || _hash_lock == 0,
 475             "remove node from hash table before modifying it");
 476     Node** p = &_in[i];    // cache this._in, across the del_out call
 477     if (*p != nullptr)  (*p)->del_out((Node *)this);
 478     (*p) = n;
 479     if (n != nullptr)      n->add_out((Node *)this);
 480     Compile::current()->record_modified_node(this);
 481   }
 482   // Light version of set_req() to init inputs after node creation.
 483   void init_req( uint i, Node *n ) {
 484     assert( (i == 0 && this == n) ||
 485             is_not_dead(n), "can not use dead node");
 486     assert( i < _cnt, "oob");
 487     assert( !VerifyHashTableKeys || _hash_lock == 0,
 488             "remove node from hash table before modifying it");
 489     assert( _in[i] == nullptr, "sanity");
 490     _in[i] = n;
 491     if (n != nullptr)      n->add_out((Node *)this);
 492     Compile::current()->record_modified_node(this);
 493   }
 494   // Find first occurrence of n among my edges:
 495   int find_edge(Node* n);
 496   int find_prec_edge(Node* n) {
 497     for (uint i = req(); i < len(); i++) {
 498       if (_in[i] == n) return i;
 499       if (_in[i] == nullptr) {
 500         DEBUG_ONLY( while ((++i) < len()) assert(_in[i] == nullptr, "Gap in prec edges!"); )
 501         break;
 502       }
 503     }
 504     return -1;
 505   }
 506   int replace_edge(Node* old, Node* neww, PhaseGVN* gvn = nullptr);
 507   int replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn);
 508   // null out all inputs to eliminate incoming Def-Use edges.
 509   void disconnect_inputs(Compile* C);
 510 
 511   // Quickly, return true if and only if I am Compile::current()->top().
 512   bool is_top() const {
 513     assert((this == (Node*) Compile::current()->top()) == (_out == nullptr), "");
 514     return (_out == nullptr);
 515   }
 516   // Reaffirm invariants for is_top.  (Only from Compile::set_cached_top_node.)
 517   void setup_is_top();
 518 
 519   // Strip away casting.  (It is depth-limited.)
 520   Node* uncast(bool keep_deps = false) const;
 521   // Return whether two Nodes are equivalent, after stripping casting.
 522   bool eqv_uncast(const Node* n, bool keep_deps = false) const {
 523     return (this->uncast(keep_deps) == n->uncast(keep_deps));
 524   }
 525 
 526   // Find out of current node that matches opcode.
 527   Node* find_out_with(int opcode);
 528   // Return true if the current node has an out that matches opcode.
 529   bool has_out_with(int opcode);
 530   // Return true if the current node has an out that matches any of the opcodes.
 531   bool has_out_with(int opcode1, int opcode2, int opcode3, int opcode4);
 532 
 533 private:
 534   static Node* uncast_helper(const Node* n, bool keep_deps);
 535 
 536   // Add an output edge to the end of the list
 537   void add_out( Node *n ) {
 538     if (is_top())  return;
 539     if( _outcnt == _outmax ) out_grow(_outcnt);
 540     _out[_outcnt++] = n;
 541   }
 542   // Delete an output edge
 543   void del_out( Node *n ) {
 544     if (is_top())  return;
 545     Node** outp = &_out[_outcnt];
 546     // Find and remove n
 547     do {
 548       assert(outp > _out, "Missing Def-Use edge");
 549     } while (*--outp != n);
 550     *outp = _out[--_outcnt];
 551     // Smash the old edge so it can't be used accidentally.
 552     DEBUG_ONLY(_out[_outcnt] = (Node *)(uintptr_t)0xdeadbeef);
 553     // Record that a change happened here.
 554     #if OPTO_DU_ITERATOR_ASSERT
 555     DEBUG_ONLY(_last_del = n; ++_del_tick);
 556     #endif
 557   }
 558   // Close gap after removing edge.
 559   void close_prec_gap_at(uint gap) {
 560     assert(_cnt <= gap && gap < _max, "no valid prec edge");
 561     uint i = gap;
 562     Node *last = nullptr;
 563     for (; i < _max-1; ++i) {
 564       Node *next = _in[i+1];
 565       if (next == nullptr) break;
 566       last = next;
 567     }
 568     _in[gap] = last;  // Move last slot to empty one.
 569     _in[i] = nullptr; // null out last slot.
 570   }
 571 
 572 public:
 573   // Globally replace this node by a given new node, updating all uses.
 574   void replace_by(Node* new_node);
 575   // Globally replace this node by a given new node, updating all uses
 576   // and cutting input edges of old node.
 577   void subsume_by(Node* new_node, Compile* c) {
 578     replace_by(new_node);
 579     disconnect_inputs(c);
 580   }
 581   void set_req_X(uint i, Node *n, PhaseIterGVN *igvn);
 582   void set_req_X(uint i, Node *n, PhaseGVN *gvn);
 583   // Find the one non-null required input.  RegionNode only
 584   Node *nonnull_req() const;
 585   // Add or remove precedence edges
 586   void add_prec( Node *n );
 587   void rm_prec( uint i );
 588 
 589   // Note: prec(i) will not necessarily point to n if edge already exists.
 590   void set_prec( uint i, Node *n ) {
 591     assert(i < _max, "oob: i=%d, _max=%d", i, _max);
 592     assert(is_not_dead(n), "can not use dead node");
 593     assert(i >= _cnt, "not a precedence edge");
 594     // Avoid spec violation: duplicated prec edge.
 595     if (_in[i] == n) return;
 596     if (n == nullptr || find_prec_edge(n) != -1) {
 597       rm_prec(i);
 598       return;
 599     }
 600     if (_in[i] != nullptr) _in[i]->del_out((Node *)this);
 601     _in[i] = n;
 602     n->add_out((Node *)this);
 603     Compile::current()->record_modified_node(this);
 604   }
 605 
 606   // Set this node's index, used by cisc_version to replace current node
 607   void set_idx(uint new_idx) {
 608     _idx = new_idx;
 609   }
 610   // Swap input edge order.  (Edge indexes i1 and i2 are usually 1 and 2.)
 611   void swap_edges(uint i1, uint i2) {
 612     DEBUG_ONLY(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
 613     // Def-Use info is unchanged
 614     Node* n1 = in(i1);
 615     Node* n2 = in(i2);
 616     _in[i1] = n2;
 617     _in[i2] = n1;
 618     // If this node is in the hash table, make sure it doesn't need a rehash.
 619     assert(check_hash == NO_HASH || check_hash == hash(), "edge swap must preserve hash code");
 620     // Flip swapped edges flag.
 621     if (has_swapped_edges()) {
 622       remove_flag(Node::Flag_has_swapped_edges);
 623     } else {
 624       add_flag(Node::Flag_has_swapped_edges);
 625     }
 626   }
 627 
 628   // Iterators over input Nodes for a Node X are written as:
 629   // for( i = 0; i < X.req(); i++ ) ... X[i] ...
 630   // NOTE: Required edges can contain embedded null pointers.
 631 
 632 //----------------- Other Node Properties
 633 
 634   // Generate class IDs for (some) ideal nodes so that it is possible to determine
 635   // the type of a node using a non-virtual method call (the method is_<Node>() below).
 636   //
 637   // A class ID of an ideal node is a set of bits. In a class ID, a single bit determines
 638   // the type of the node the ID represents; another subset of an ID's bits are reserved
 639   // for the superclasses of the node represented by the ID.
 640   //
 641   // By design, if A is a supertype of B, A.is_B() returns true and B.is_A()
 642   // returns false. A.is_A() returns true.
 643   //
 644   // If two classes, A and B, have the same superclass, a different bit of A's class id
 645   // is reserved for A's type than for B's type. That bit is specified by the third
 646   // parameter in the macro DEFINE_CLASS_ID.
 647   //
 648   // By convention, classes with deeper hierarchy are declared first. Moreover,
 649   // classes with the same hierarchy depth are sorted by usage frequency.
 650   //
 651   // The query method masks the bits to cut off bits of subclasses and then compares
 652   // the result with the class id (see the macro DEFINE_CLASS_QUERY below).
 653   //
 654   //  Class_MachCall=30, ClassMask_MachCall=31
 655   // 12               8               4               0
 656   //  0   0   0   0   0   0   0   0   1   1   1   1   0
 657   //                                  |   |   |   |
 658   //                                  |   |   |   Bit_Mach=2
 659   //                                  |   |   Bit_MachReturn=4
 660   //                                  |   Bit_MachSafePoint=8
 661   //                                  Bit_MachCall=16
 662   //
 663   //  Class_CountedLoop=56, ClassMask_CountedLoop=63
 664   // 12               8               4               0
 665   //  0   0   0   0   0   0   0   1   1   1   0   0   0
 666   //                              |   |   |
 667   //                              |   |   Bit_Region=8
 668   //                              |   Bit_Loop=16
 669   //                              Bit_CountedLoop=32
 670 
 671   #define DEFINE_CLASS_ID(cl, supcl, subn) \
 672   Bit_##cl = (Class_##supcl == 0) ? 1 << subn : (Bit_##supcl) << (1 + subn) , \
 673   Class_##cl = Class_##supcl + Bit_##cl , \
 674   ClassMask_##cl = ((Bit_##cl << 1) - 1) ,
 675 
 676   // This enum is used only for C2 ideal and mach nodes with is_<node>() methods
 677   // so that its values fit into 32 bits.
 678   enum NodeClasses {
 679     Bit_Node   = 0x00000000,
 680     Class_Node = 0x00000000,
 681     ClassMask_Node = 0xFFFFFFFF,
 682 
 683     DEFINE_CLASS_ID(Multi, Node, 0)
 684       DEFINE_CLASS_ID(SafePoint, Multi, 0)
 685         DEFINE_CLASS_ID(Call,      SafePoint, 0)
 686           DEFINE_CLASS_ID(CallJava,         Call, 0)
 687             DEFINE_CLASS_ID(CallStaticJava,   CallJava, 0)
 688             DEFINE_CLASS_ID(CallDynamicJava,  CallJava, 1)
 689           DEFINE_CLASS_ID(CallRuntime,      Call, 1)
 690             DEFINE_CLASS_ID(CallLeaf,         CallRuntime, 0)
 691               DEFINE_CLASS_ID(CallLeafNoFP,     CallLeaf, 0)
 692               DEFINE_CLASS_ID(CallLeafPure,     CallLeaf, 1)
 693           DEFINE_CLASS_ID(Allocate,         Call, 2)
 694             DEFINE_CLASS_ID(AllocateArray,    Allocate, 0)
 695           DEFINE_CLASS_ID(AbstractLock,     Call, 3)
 696             DEFINE_CLASS_ID(Lock,             AbstractLock, 0)
 697             DEFINE_CLASS_ID(Unlock,           AbstractLock, 1)
 698           DEFINE_CLASS_ID(ArrayCopy,        Call, 4)
 699         DEFINE_CLASS_ID(LoadFlat,  SafePoint, 1)
 700         DEFINE_CLASS_ID(StoreFlat, SafePoint, 2)
 701       DEFINE_CLASS_ID(MultiBranch, Multi, 1)
 702         DEFINE_CLASS_ID(PCTable,     MultiBranch, 0)
 703           DEFINE_CLASS_ID(Catch,       PCTable, 0)
 704           DEFINE_CLASS_ID(Jump,        PCTable, 1)
 705         DEFINE_CLASS_ID(If,          MultiBranch, 1)
 706           DEFINE_CLASS_ID(BaseCountedLoopEnd,     If, 0)
 707             DEFINE_CLASS_ID(CountedLoopEnd,       BaseCountedLoopEnd, 0)
 708             DEFINE_CLASS_ID(LongCountedLoopEnd,   BaseCountedLoopEnd, 1)
 709           DEFINE_CLASS_ID(RangeCheck,             If, 1)
 710           DEFINE_CLASS_ID(OuterStripMinedLoopEnd, If, 2)
 711           DEFINE_CLASS_ID(ParsePredicate,         If, 3)
 712         DEFINE_CLASS_ID(NeverBranch, MultiBranch, 2)
 713       DEFINE_CLASS_ID(Start,       Multi, 2)
 714       DEFINE_CLASS_ID(MemBar,      Multi, 3)
 715         DEFINE_CLASS_ID(Initialize,       MemBar, 0)
 716         DEFINE_CLASS_ID(MemBarStoreStore, MemBar, 1)
 717         DEFINE_CLASS_ID(Blackhole,        MemBar, 2)
 718 
 719     DEFINE_CLASS_ID(Mach,  Node, 1)
 720       DEFINE_CLASS_ID(MachReturn, Mach, 0)
 721         DEFINE_CLASS_ID(MachSafePoint, MachReturn, 0)
 722           DEFINE_CLASS_ID(MachCall, MachSafePoint, 0)
 723             DEFINE_CLASS_ID(MachCallJava,         MachCall, 0)
 724               DEFINE_CLASS_ID(MachCallStaticJava,   MachCallJava, 0)
 725               DEFINE_CLASS_ID(MachCallDynamicJava,  MachCallJava, 1)
 726             DEFINE_CLASS_ID(MachCallRuntime,      MachCall, 1)
 727               DEFINE_CLASS_ID(MachCallLeaf,         MachCallRuntime, 0)
 728       DEFINE_CLASS_ID(MachBranch, Mach, 1)
 729         DEFINE_CLASS_ID(MachIf,         MachBranch, 0)
 730         DEFINE_CLASS_ID(MachGoto,       MachBranch, 1)
 731         DEFINE_CLASS_ID(MachNullCheck,  MachBranch, 2)
 732       DEFINE_CLASS_ID(MachSpillCopy,    Mach, 2)
 733       DEFINE_CLASS_ID(MachTemp,         Mach, 3)
 734       DEFINE_CLASS_ID(MachConstantBase, Mach, 4)
 735       DEFINE_CLASS_ID(MachConstant,     Mach, 5)
 736         DEFINE_CLASS_ID(MachJump,       MachConstant, 0)
 737       DEFINE_CLASS_ID(MachMerge,        Mach, 6)
 738       DEFINE_CLASS_ID(MachMemBar,       Mach, 7)
 739       DEFINE_CLASS_ID(MachProlog,       Mach, 8)
 740       DEFINE_CLASS_ID(MachVEP,          Mach, 9)
 741 
 742     DEFINE_CLASS_ID(Type,  Node, 2)
 743       DEFINE_CLASS_ID(Phi,   Type, 0)
 744       DEFINE_CLASS_ID(ConstraintCast, Type, 1)
 745         DEFINE_CLASS_ID(CastII, ConstraintCast, 0)
 746         DEFINE_CLASS_ID(CheckCastPP, ConstraintCast, 1)
 747         DEFINE_CLASS_ID(CastLL, ConstraintCast, 2)
 748         DEFINE_CLASS_ID(CastFF, ConstraintCast, 3)
 749         DEFINE_CLASS_ID(CastDD, ConstraintCast, 4)
 750         DEFINE_CLASS_ID(CastVV, ConstraintCast, 5)
 751         DEFINE_CLASS_ID(CastPP, ConstraintCast, 6)
 752         DEFINE_CLASS_ID(CastHH, ConstraintCast, 7)
 753       DEFINE_CLASS_ID(CMove, Type, 3)
 754       DEFINE_CLASS_ID(SafePointScalarObject, Type, 4)
 755       DEFINE_CLASS_ID(DecodeNarrowPtr, Type, 5)
 756         DEFINE_CLASS_ID(DecodeN, DecodeNarrowPtr, 0)
 757         DEFINE_CLASS_ID(DecodeNKlass, DecodeNarrowPtr, 1)
 758       DEFINE_CLASS_ID(EncodeNarrowPtr, Type, 6)
 759         DEFINE_CLASS_ID(EncodeP, EncodeNarrowPtr, 0)
 760         DEFINE_CLASS_ID(EncodePKlass, EncodeNarrowPtr, 1)
 761       DEFINE_CLASS_ID(Vector, Type, 7)
 762         DEFINE_CLASS_ID(VectorMaskCmp, Vector, 0)
 763         DEFINE_CLASS_ID(VectorUnbox, Vector, 1)
 764         DEFINE_CLASS_ID(VectorReinterpret, Vector, 2)
 765         DEFINE_CLASS_ID(ShiftV, Vector, 3)
 766         DEFINE_CLASS_ID(CompressV, Vector, 4)
 767         DEFINE_CLASS_ID(ExpandV, Vector, 5)
 768         DEFINE_CLASS_ID(CompressM, Vector, 6)
 769         DEFINE_CLASS_ID(Reduction, Vector, 7)
 770         DEFINE_CLASS_ID(NegV, Vector, 8)
 771         DEFINE_CLASS_ID(SaturatingVector, Vector, 9)
 772         DEFINE_CLASS_ID(MulVL, Vector, 10)
 773       DEFINE_CLASS_ID(InlineType, Type, 8)
 774       DEFINE_CLASS_ID(Con, Type, 9)
 775           DEFINE_CLASS_ID(ConI, Con, 0)
 776       DEFINE_CLASS_ID(SafePointScalarMerge, Type, 10)
 777       DEFINE_CLASS_ID(Convert, Type, 11)
 778 
 779 
 780     DEFINE_CLASS_ID(Proj,  Node, 3)
 781       DEFINE_CLASS_ID(CatchProj, Proj, 0)
 782       DEFINE_CLASS_ID(JumpProj,  Proj, 1)
 783       DEFINE_CLASS_ID(IfProj,    Proj, 2)
 784         DEFINE_CLASS_ID(IfTrue,    IfProj, 0)
 785         DEFINE_CLASS_ID(IfFalse,   IfProj, 1)
 786       DEFINE_CLASS_ID(Parm,      Proj, 4)
 787       DEFINE_CLASS_ID(MachProj,  Proj, 5)
 788       DEFINE_CLASS_ID(NarrowMemProj, Proj, 6)
 789 
 790     DEFINE_CLASS_ID(Mem, Node, 4)
 791       DEFINE_CLASS_ID(Load, Mem, 0)
 792         DEFINE_CLASS_ID(LoadVector,  Load, 0)
 793           DEFINE_CLASS_ID(LoadVectorGather, LoadVector, 0)
 794           DEFINE_CLASS_ID(LoadVectorGatherMasked, LoadVector, 1)
 795           DEFINE_CLASS_ID(LoadVectorMasked, LoadVector, 2)
 796       DEFINE_CLASS_ID(Store, Mem, 1)
 797         DEFINE_CLASS_ID(StoreVector, Store, 0)
 798           DEFINE_CLASS_ID(StoreVectorScatter, StoreVector, 0)
 799           DEFINE_CLASS_ID(StoreVectorScatterMasked, StoreVector, 1)
 800           DEFINE_CLASS_ID(StoreVectorMasked, StoreVector, 2)
 801       DEFINE_CLASS_ID(LoadStore, Mem, 2)
 802         DEFINE_CLASS_ID(LoadStoreConditional, LoadStore, 0)
 803           DEFINE_CLASS_ID(CompareAndSwap, LoadStoreConditional, 0)
 804         DEFINE_CLASS_ID(CompareAndExchangeNode, LoadStore, 1)
 805 
 806     DEFINE_CLASS_ID(Region, Node, 5)
 807       DEFINE_CLASS_ID(Loop, Region, 0)
 808         DEFINE_CLASS_ID(Root,                Loop, 0)
 809         DEFINE_CLASS_ID(BaseCountedLoop,     Loop, 1)
 810           DEFINE_CLASS_ID(CountedLoop,       BaseCountedLoop, 0)
 811           DEFINE_CLASS_ID(LongCountedLoop,   BaseCountedLoop, 1)
 812         DEFINE_CLASS_ID(OuterStripMinedLoop, Loop, 2)
 813 
 814     DEFINE_CLASS_ID(Sub,   Node, 6)
 815       DEFINE_CLASS_ID(Cmp,   Sub, 0)
 816         DEFINE_CLASS_ID(FastLock,       Cmp, 0)
 817         DEFINE_CLASS_ID(FastUnlock,     Cmp, 1)
 818         DEFINE_CLASS_ID(SubTypeCheck,   Cmp, 2)
 819         DEFINE_CLASS_ID(FlatArrayCheck, Cmp, 3)
 820 
 821     DEFINE_CLASS_ID(MergeMem, Node, 7)
 822     DEFINE_CLASS_ID(Bool,     Node, 8)
 823     DEFINE_CLASS_ID(AddP,     Node, 9)
 824     DEFINE_CLASS_ID(BoxLock,  Node, 10)
 825     DEFINE_CLASS_ID(Add,      Node, 11)
 826       DEFINE_CLASS_ID(MinMax,      Add, 0)
 827     DEFINE_CLASS_ID(Mul,      Node, 12)
 828     DEFINE_CLASS_ID(ClearArray, Node, 14)
 829     DEFINE_CLASS_ID(Halt,     Node, 15)
 830     DEFINE_CLASS_ID(Opaque1,  Node, 16)
 831       DEFINE_CLASS_ID(OpaqueLoopInit, Opaque1, 0)
 832       DEFINE_CLASS_ID(OpaqueLoopStride, Opaque1, 1)
 833       DEFINE_CLASS_ID(OpaqueMultiversioning, Opaque1, 2)
 834     DEFINE_CLASS_ID(OpaqueNotNull,  Node, 17)
 835     DEFINE_CLASS_ID(OpaqueInitializedAssertionPredicate,  Node, 18)
 836     DEFINE_CLASS_ID(OpaqueTemplateAssertionPredicate,  Node, 19)
 837     DEFINE_CLASS_ID(Move,     Node, 20)
 838     DEFINE_CLASS_ID(LShift,   Node, 21)
 839     DEFINE_CLASS_ID(Neg,      Node, 22)
 840 
 841     _max_classes  = ClassMask_Neg
 842   };
 843   #undef DEFINE_CLASS_ID
 844 
 845   // Flags are sorted by usage frequency.
 846   enum NodeFlags : uint64_t {
 847     Flag_is_Copy                     = 1ULL << 0, // should be first bit to avoid shift
 848     Flag_rematerialize               = 1ULL << 1,
 849     Flag_needs_anti_dependence_check = 1ULL << 2,
 850     Flag_is_macro                    = 1ULL << 3,
 851     Flag_is_Con                      = 1ULL << 4,
 852     Flag_is_cisc_alternate           = 1ULL << 5,
 853     Flag_is_dead_loop_safe           = 1ULL << 6,
 854     Flag_may_be_short_branch         = 1ULL << 7,
 855     Flag_avoid_back_to_back_before   = 1ULL << 8,
 856     Flag_avoid_back_to_back_after    = 1ULL << 9,
 857     Flag_has_call                    = 1ULL << 10,
 858     Flag_has_swapped_edges           = 1ULL << 11,
 859     Flag_is_scheduled                = 1ULL << 12,
 860     Flag_is_expensive                = 1ULL << 13,
 861     Flag_is_predicated_vector        = 1ULL << 14,
 862     Flag_for_post_loop_opts_igvn     = 1ULL << 15,
 863     Flag_for_merge_stores_igvn       = 1ULL << 16,
 864     Flag_is_removed_by_peephole      = 1ULL << 17,
 865     Flag_is_predicated_using_blend   = 1ULL << 18,
 866     _last_flag                       = Flag_is_predicated_using_blend
 867   };
 868 
 869   class PD;
 870 
 871 private:
 872   juint _class_id;
 873   juint _flags;
 874 
 875 #ifdef ASSERT
 876   static juint max_flags();
 877 #endif
 878 
 879 protected:
 880   // These methods should be called from constructors only.
 881   void init_class_id(juint c) {
 882     _class_id = c; // cast out const
 883   }
 884   void init_flags(uint fl) {
 885     assert(fl <= max_flags(), "invalid node flag");
 886     _flags |= fl;
 887   }
 888   void clear_flag(uint fl) {
 889     assert(fl <= max_flags(), "invalid node flag");
 890     _flags &= ~fl;
 891   }
 892 
 893 public:
 894   juint class_id() const { return _class_id; }
 895 
 896   juint flags() const { return _flags; }
 897 
 898   void add_flag(juint fl) { init_flags(fl); }
 899 
 900   void remove_flag(juint fl) { clear_flag(fl); }
 901 
 902   // Return a dense integer opcode number
 903   virtual int Opcode() const;
 904 
 905   // Virtual inherited Node size
 906   virtual uint size_of() const;
 907 
 908   // Other interesting Node properties
 909   #define DEFINE_CLASS_QUERY(type)                           \
 910   bool is_##type() const {                                   \
 911     return ((_class_id & ClassMask_##type) == Class_##type); \
 912   }                                                          \
 913   type##Node *as_##type() const {                            \
 914     assert(is_##type(), "invalid node class: %s", Name());   \
 915     return (type##Node*)this;                                \
 916   }                                                          \
 917   type##Node* isa_##type() const {                           \
 918     return (is_##type()) ? as_##type() : nullptr;            \
 919   }
 920 
 921   DEFINE_CLASS_QUERY(AbstractLock)
 922   DEFINE_CLASS_QUERY(Add)
 923   DEFINE_CLASS_QUERY(AddP)
 924   DEFINE_CLASS_QUERY(Allocate)
 925   DEFINE_CLASS_QUERY(AllocateArray)
 926   DEFINE_CLASS_QUERY(ArrayCopy)
 927   DEFINE_CLASS_QUERY(BaseCountedLoop)
 928   DEFINE_CLASS_QUERY(BaseCountedLoopEnd)
 929   DEFINE_CLASS_QUERY(Blackhole)
 930   DEFINE_CLASS_QUERY(Bool)
 931   DEFINE_CLASS_QUERY(BoxLock)
 932   DEFINE_CLASS_QUERY(Call)
 933   DEFINE_CLASS_QUERY(CallDynamicJava)
 934   DEFINE_CLASS_QUERY(CallJava)
 935   DEFINE_CLASS_QUERY(CallLeaf)
 936   DEFINE_CLASS_QUERY(CallLeafNoFP)
 937   DEFINE_CLASS_QUERY(CallLeafPure)
 938   DEFINE_CLASS_QUERY(CallRuntime)
 939   DEFINE_CLASS_QUERY(CallStaticJava)
 940   DEFINE_CLASS_QUERY(Catch)
 941   DEFINE_CLASS_QUERY(CatchProj)
 942   DEFINE_CLASS_QUERY(CheckCastPP)
 943   DEFINE_CLASS_QUERY(CastII)
 944   DEFINE_CLASS_QUERY(CastLL)
 945   DEFINE_CLASS_QUERY(CastFF)
 946   DEFINE_CLASS_QUERY(ConI)
 947   DEFINE_CLASS_QUERY(CastPP)
 948   DEFINE_CLASS_QUERY(ConstraintCast)
 949   DEFINE_CLASS_QUERY(ClearArray)
 950   DEFINE_CLASS_QUERY(CMove)
 951   DEFINE_CLASS_QUERY(Cmp)
 952   DEFINE_CLASS_QUERY(Convert)
 953   DEFINE_CLASS_QUERY(CountedLoop)
 954   DEFINE_CLASS_QUERY(CountedLoopEnd)
 955   DEFINE_CLASS_QUERY(DecodeNarrowPtr)
 956   DEFINE_CLASS_QUERY(DecodeN)
 957   DEFINE_CLASS_QUERY(DecodeNKlass)
 958   DEFINE_CLASS_QUERY(EncodeNarrowPtr)
 959   DEFINE_CLASS_QUERY(EncodeP)
 960   DEFINE_CLASS_QUERY(EncodePKlass)
 961   DEFINE_CLASS_QUERY(FastLock)
 962   DEFINE_CLASS_QUERY(FastUnlock)
 963   DEFINE_CLASS_QUERY(FlatArrayCheck)
 964   DEFINE_CLASS_QUERY(Halt)
 965   DEFINE_CLASS_QUERY(If)
 966   DEFINE_CLASS_QUERY(RangeCheck)
 967   DEFINE_CLASS_QUERY(IfProj)
 968   DEFINE_CLASS_QUERY(IfFalse)
 969   DEFINE_CLASS_QUERY(IfTrue)
 970   DEFINE_CLASS_QUERY(Initialize)
 971   DEFINE_CLASS_QUERY(Jump)
 972   DEFINE_CLASS_QUERY(JumpProj)
 973   DEFINE_CLASS_QUERY(LongCountedLoop)
 974   DEFINE_CLASS_QUERY(LongCountedLoopEnd)
 975   DEFINE_CLASS_QUERY(Load)
 976   DEFINE_CLASS_QUERY(LoadStore)
 977   DEFINE_CLASS_QUERY(LoadStoreConditional)
 978   DEFINE_CLASS_QUERY(Lock)
 979   DEFINE_CLASS_QUERY(Loop)
 980   DEFINE_CLASS_QUERY(LShift)
 981   DEFINE_CLASS_QUERY(Mach)
 982   DEFINE_CLASS_QUERY(MachBranch)
 983   DEFINE_CLASS_QUERY(MachCall)
 984   DEFINE_CLASS_QUERY(MachCallDynamicJava)
 985   DEFINE_CLASS_QUERY(MachCallJava)
 986   DEFINE_CLASS_QUERY(MachCallLeaf)
 987   DEFINE_CLASS_QUERY(MachCallRuntime)
 988   DEFINE_CLASS_QUERY(MachCallStaticJava)
 989   DEFINE_CLASS_QUERY(MachConstantBase)
 990   DEFINE_CLASS_QUERY(MachConstant)
 991   DEFINE_CLASS_QUERY(MachGoto)
 992   DEFINE_CLASS_QUERY(MachIf)
 993   DEFINE_CLASS_QUERY(MachJump)
 994   DEFINE_CLASS_QUERY(MachNullCheck)
 995   DEFINE_CLASS_QUERY(MachProj)
 996   DEFINE_CLASS_QUERY(MachProlog)
 997   DEFINE_CLASS_QUERY(MachReturn)
 998   DEFINE_CLASS_QUERY(MachSafePoint)
 999   DEFINE_CLASS_QUERY(MachSpillCopy)
1000   DEFINE_CLASS_QUERY(MachTemp)
1001   DEFINE_CLASS_QUERY(MachMemBar)
1002   DEFINE_CLASS_QUERY(MachMerge)
1003   DEFINE_CLASS_QUERY(MachVEP)
1004   DEFINE_CLASS_QUERY(Mem)
1005   DEFINE_CLASS_QUERY(MemBar)
1006   DEFINE_CLASS_QUERY(MemBarStoreStore)
1007   DEFINE_CLASS_QUERY(MergeMem)
1008   DEFINE_CLASS_QUERY(MinMax)
1009   DEFINE_CLASS_QUERY(Move)
1010   DEFINE_CLASS_QUERY(Mul)
1011   DEFINE_CLASS_QUERY(Multi)
1012   DEFINE_CLASS_QUERY(MultiBranch)
1013   DEFINE_CLASS_QUERY(MulVL)
1014   DEFINE_CLASS_QUERY(NarrowMemProj)
1015   DEFINE_CLASS_QUERY(Neg)
1016   DEFINE_CLASS_QUERY(NegV)
1017   DEFINE_CLASS_QUERY(NeverBranch)
1018   DEFINE_CLASS_QUERY(Opaque1)
1019   DEFINE_CLASS_QUERY(OpaqueNotNull)
1020   DEFINE_CLASS_QUERY(OpaqueInitializedAssertionPredicate)
1021   DEFINE_CLASS_QUERY(OpaqueTemplateAssertionPredicate)
1022   DEFINE_CLASS_QUERY(OpaqueLoopInit)
1023   DEFINE_CLASS_QUERY(OpaqueLoopStride)
1024   DEFINE_CLASS_QUERY(OpaqueMultiversioning)
1025   DEFINE_CLASS_QUERY(OuterStripMinedLoop)
1026   DEFINE_CLASS_QUERY(OuterStripMinedLoopEnd)
1027   DEFINE_CLASS_QUERY(Parm)
1028   DEFINE_CLASS_QUERY(ParsePredicate)
1029   DEFINE_CLASS_QUERY(PCTable)
1030   DEFINE_CLASS_QUERY(Phi)
1031   DEFINE_CLASS_QUERY(Proj)
1032   DEFINE_CLASS_QUERY(Reduction)
1033   DEFINE_CLASS_QUERY(Region)
1034   DEFINE_CLASS_QUERY(Root)
1035   DEFINE_CLASS_QUERY(SafePoint)
1036   DEFINE_CLASS_QUERY(SafePointScalarObject)
1037   DEFINE_CLASS_QUERY(SafePointScalarMerge)
1038   DEFINE_CLASS_QUERY(Start)
1039   DEFINE_CLASS_QUERY(Store)
1040   DEFINE_CLASS_QUERY(Sub)
1041   DEFINE_CLASS_QUERY(SubTypeCheck)
1042   DEFINE_CLASS_QUERY(Type)
1043   DEFINE_CLASS_QUERY(InlineType)
1044   DEFINE_CLASS_QUERY(LoadFlat)
1045   DEFINE_CLASS_QUERY(StoreFlat)
1046   DEFINE_CLASS_QUERY(Vector)
1047   DEFINE_CLASS_QUERY(VectorMaskCmp)
1048   DEFINE_CLASS_QUERY(VectorUnbox)
1049   DEFINE_CLASS_QUERY(VectorReinterpret)
1050   DEFINE_CLASS_QUERY(CompressV)
1051   DEFINE_CLASS_QUERY(ExpandV)
1052   DEFINE_CLASS_QUERY(CompressM)
1053   DEFINE_CLASS_QUERY(LoadVector)
1054   DEFINE_CLASS_QUERY(LoadVectorGather)
1055   DEFINE_CLASS_QUERY(LoadVectorMasked)
1056   DEFINE_CLASS_QUERY(LoadVectorGatherMasked)
1057   DEFINE_CLASS_QUERY(StoreVector)
1058   DEFINE_CLASS_QUERY(StoreVectorScatter)
1059   DEFINE_CLASS_QUERY(StoreVectorMasked)
1060   DEFINE_CLASS_QUERY(StoreVectorScatterMasked)
1061   DEFINE_CLASS_QUERY(SaturatingVector)
1062   DEFINE_CLASS_QUERY(ShiftV)
1063   DEFINE_CLASS_QUERY(Unlock)
1064 
1065   #undef DEFINE_CLASS_QUERY
1066 
1067   // duplicate of is_MachSpillCopy()
1068   bool is_SpillCopy () const {
1069     return ((_class_id & ClassMask_MachSpillCopy) == Class_MachSpillCopy);
1070   }
1071 
1072   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
1073   // The data node which is safe to leave in dead loop during IGVN optimization.
1074   bool is_dead_loop_safe() const;
1075 
1076   // is_Copy() returns copied edge index (0 or 1)
1077   uint is_Copy() const { return (_flags & Flag_is_Copy); }
1078 
1079   virtual bool is_CFG() const { return false; }
1080 
1081   // If this node is control-dependent on a test, can it be
1082   // rerouted to a dominating equivalent test?  This is usually
1083   // true of non-CFG nodes, but can be false for operations which
1084   // depend for their correct sequencing on more than one test.
1085   // (In that case, hoisting to a dominating test may silently
1086   // skip some other important test.)
1087   virtual bool depends_only_on_test() const { assert(!is_CFG(), ""); return true; };
1088 
1089   // When building basic blocks, I need to have a notion of block beginning
1090   // Nodes, next block selector Nodes (block enders), and next block
1091   // projections.  These calls need to work on their machine equivalents.  The
1092   // Ideal beginning Nodes are RootNode, RegionNode and StartNode.
1093   bool is_block_start() const {
1094     if ( is_Region() )
1095       return this == (const Node*)in(0);
1096     else
1097       return is_Start();
1098   }
1099 
1100   // The Ideal control projection Nodes are IfTrue/IfFalse, JumpProjNode, Root,
1101   // Goto and Return.  This call also returns the block ending Node.
1102   virtual const Node *is_block_proj() const;
1103 
1104   // The node is a "macro" node which needs to be expanded before matching
1105   bool is_macro() const { return (_flags & Flag_is_macro) != 0; }
1106   // The node is expensive: the best control is set during loop opts
1107   bool is_expensive() const { return (_flags & Flag_is_expensive) != 0 && in(0) != nullptr; }
1108   // The node's original edge position is swapped.
1109   bool has_swapped_edges() const { return (_flags & Flag_has_swapped_edges) != 0; }
1110 
1111   bool is_predicated_vector() const { return (_flags & Flag_is_predicated_vector) != 0; }
1112 
1113   bool is_predicated_using_blend() const { return (_flags & Flag_is_predicated_using_blend) != 0; }
1114 
1115   // Used in lcm to mark nodes that have scheduled
1116   bool is_scheduled() const { return (_flags & Flag_is_scheduled) != 0; }
1117 
1118   bool for_post_loop_opts_igvn() const { return (_flags & Flag_for_post_loop_opts_igvn) != 0; }
1119   bool for_merge_stores_igvn() const { return (_flags & Flag_for_merge_stores_igvn) != 0; }
1120 
1121   // Is 'n' possibly a loop entry (i.e. a Parse Predicate projection)?
1122   static bool may_be_loop_entry(Node* n) {
1123     return n != nullptr && n->is_IfProj() && n->in(0)->is_ParsePredicate();
1124   }
1125 
1126 //----------------- Optimization
1127 
1128   // Get the worst-case Type output for this Node.
1129   virtual const class Type *bottom_type() const;
1130 
1131   // If we find a better type for a node, try to record it permanently.
1132   // Return true if this node actually changed.
1133   // Be sure to do the hash_delete game in the "rehash" variant.
1134   void raise_bottom_type(const Type* new_type);
1135 
1136   // Get the address type with which this node uses and/or defs memory,
1137   // or null if none.  The address type is conservatively wide.
1138   // Returns non-null for calls, membars, loads, stores, etc.
1139   // Returns TypePtr::BOTTOM if the node touches memory "broadly".
1140   virtual const class TypePtr *adr_type() const { return nullptr; }
1141 
1142   // Return an existing node which computes the same function as this node.
1143   // The optimistic combined algorithm requires this to return a Node which
1144   // is a small number of steps away (e.g., one of my inputs).
1145   virtual Node* Identity(PhaseGVN* phase);
1146 
1147   // Return the set of values this Node can take on at runtime.
1148   virtual const Type* Value(PhaseGVN* phase) const;
1149 
1150   // Return a node which is more "ideal" than the current node.
1151   // The invariants on this call are subtle.  If in doubt, read the
1152   // treatise in node.cpp above the default implementation AND TEST WITH
1153   // -XX:VerifyIterativeGVN=1
1154   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
1155 
1156   // Some nodes have specific Ideal subgraph transformations only if they are
1157   // unique users of specific nodes. Such nodes should be put on IGVN worklist
1158   // for the transformations to happen.
1159   bool has_special_unique_user() const;
1160 
1161   // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1162   Node* find_exact_control(Node* ctrl);
1163 
1164   // Results of the dominance analysis.
1165   enum class DomResult {
1166     NotDominate,         // 'this' node does not dominate 'sub'.
1167     Dominate,            // 'this' node dominates or is equal to 'sub'.
1168     EncounteredDeadCode  // Result is undefined due to encountering dead code.
1169   };
1170   // Check if 'this' node dominates or equal to 'sub'.
1171   DomResult dominates(Node* sub, Node_List &nlist);
1172 
1173   bool remove_dead_region(PhaseGVN *phase, bool can_reshape);
1174 public:
1175 
1176   // See if there is valid pipeline info
1177   static  const Pipeline *pipeline_class();
1178   virtual const Pipeline *pipeline() const;
1179 
1180   // Compute the latency from the def to this instruction of the ith input node
1181   uint latency(uint i);
1182 
1183   // Hash & compare functions, for pessimistic value numbering
1184 
1185   // If the hash function returns the special sentinel value NO_HASH,
1186   // the node is guaranteed never to compare equal to any other node.
1187   // If we accidentally generate a hash with value NO_HASH the node
1188   // won't go into the table and we'll lose a little optimization.
1189   static const uint NO_HASH = 0;
1190   virtual uint hash() const;
1191   virtual bool cmp( const Node &n ) const;
1192 
1193   // Operation appears to be iteratively computed (such as an induction variable)
1194   // It is possible for this operation to return false for a loop-varying
1195   // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1196   bool is_iteratively_computed();
1197 
1198   // Determine if a node is a counted loop induction variable.
1199   // NOTE: The method is defined in "loopnode.cpp".
1200   bool is_cloop_ind_var() const;
1201 
1202   // Return a node with opcode "opc" and same inputs as "this" if one can
1203   // be found; Otherwise return null;
1204   Node* find_similar(int opc);
1205   bool has_same_inputs_as(const Node* other) const;
1206 
1207   // Return the unique control out if only one. Null if none or more than one.
1208   Node* unique_ctrl_out_or_null() const;
1209   // Return the unique control out. Asserts if none or more than one control out.
1210   Node* unique_ctrl_out() const;
1211 
1212   // Set control or add control as precedence edge
1213   void ensure_control_or_add_prec(Node* c);
1214   void add_prec_from(Node* n);
1215 
1216   // Visit boundary uses of the node and apply a callback function for each.
1217   // Recursively traverse uses, stopping and applying the callback when
1218   // reaching a boundary node, defined by is_boundary. Note: the function
1219   // definition appears after the complete type definition of Node_List.
1220   template <typename Callback, typename Check>
1221   void visit_uses(Callback callback, Check is_boundary) const;
1222 
1223   // Returns a clone of the current node that's pinned (if the current node is not) for nodes found in array accesses
1224   // (Load and range check CastII nodes).
1225   // This is used when an array access is made dependent on 2 or more range checks (range check smearing or Loop Predication).
1226   virtual Node* pin_array_access_node() const {
1227     return nullptr;
1228   }
1229 
1230   //----------------- Code Generation
1231 
1232   // Ideal register class for Matching.  Zero means unmatched instruction
1233   // (these are cloned instead of converted to machine nodes).
1234   virtual uint ideal_reg() const;
1235 
1236   static const uint NotAMachineReg;   // must be > max. machine register
1237 
1238   // Do we Match on this edge index or not?  Generally false for Control
1239   // and true for everything else.  Weird for calls & returns.
1240   virtual uint match_edge(uint idx) const;
1241 
1242   // Register class output is returned in
1243   virtual const RegMask &out_RegMask() const;
1244   // Register class input is expected in
1245   virtual const RegMask &in_RegMask(uint) const;
1246   // Should we clone rather than spill this instruction?
1247   bool rematerialize() const;
1248 
1249   // Return JVM State Object if this Node carries debug info, or null otherwise
1250   virtual JVMState* jvms() const;
1251 
1252   // Print as assembly
1253   virtual void format( PhaseRegAlloc *, outputStream* st = tty ) const;
1254   // Emit bytes using C2_MacroAssembler
1255   virtual void emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const;
1256   // Size of instruction in bytes
1257   virtual uint size(PhaseRegAlloc *ra_) const;
1258 
1259   // Convenience function to extract an integer constant from a node.
1260   // If it is not an integer constant (either Con, CastII, or Mach),
1261   // return value_if_unknown.
1262   jint find_int_con(jint value_if_unknown) const {
1263     const TypeInt* t = find_int_type();
1264     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1265   }
1266   // Return the constant, knowing it is an integer constant already
1267   jint get_int() const {
1268     const TypeInt* t = find_int_type();
1269     guarantee(t != nullptr, "must be con");
1270     return t->get_con();
1271   }
1272   // Here's where the work is done.  Can produce non-constant int types too.
1273   const TypeInt* find_int_type() const;
1274   const TypeInteger* find_integer_type(BasicType bt) const;
1275 
1276   // Same thing for long (and intptr_t, via type.hpp):
1277   jlong get_long() const {
1278     const TypeLong* t = find_long_type();
1279     guarantee(t != nullptr, "must be con");
1280     return t->get_con();
1281   }
1282   jlong find_long_con(jint value_if_unknown) const {
1283     const TypeLong* t = find_long_type();
1284     return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
1285   }
1286   const TypeLong* find_long_type() const;
1287 
1288   jlong get_integer_as_long(BasicType bt) const {
1289     const TypeInteger* t = find_integer_type(bt);
1290     guarantee(t != nullptr && t->is_con(), "must be con");
1291     return t->get_con_as_long(bt);
1292   }
1293   jlong find_integer_as_long(BasicType bt, jlong value_if_unknown) const {
1294     const TypeInteger* t = find_integer_type(bt);
1295     if (t == nullptr || !t->is_con())  return value_if_unknown;
1296     return t->get_con_as_long(bt);
1297   }
1298   const TypePtr* get_ptr_type() const;
1299 
1300   // These guys are called by code generated by ADLC:
1301   intptr_t get_ptr() const;
1302   intptr_t get_narrowcon() const;
1303   jdouble getd() const;
1304   jfloat getf() const;
1305   jshort geth() const;
1306 
1307   // Nodes which are pinned into basic blocks
1308   virtual bool pinned() const { return false; }
1309 
1310   // Nodes which use memory without consuming it, hence need antidependences
1311   // More specifically, needs_anti_dependence_check returns true iff the node
1312   // (a) does a load, and (b) does not perform a store (except perhaps to a
1313   // stack slot or some other unaliased location).
1314   bool needs_anti_dependence_check() const;
1315 
1316   // Return which operand this instruction may cisc-spill. In other words,
1317   // return operand position that can convert from reg to memory access
1318   virtual int cisc_operand() const { return AdlcVMDeps::Not_cisc_spillable; }
1319   bool is_cisc_alternate() const { return (_flags & Flag_is_cisc_alternate) != 0; }
1320 
1321   // Whether this is a memory-writing machine node.
1322   bool is_memory_writer() const { return is_Mach() && bottom_type()->has_memory(); }
1323 
1324   // Whether this is a memory phi node
1325   bool is_memory_phi() const { return is_Phi() && bottom_type() == Type::MEMORY; }
1326 
1327   bool is_div_or_mod(BasicType bt) const;
1328 
1329   bool is_data_proj_of_pure_function(const Node* maybe_pure_function) const;
1330 
1331 //----------------- Printing, etc
1332 #ifndef PRODUCT
1333  public:
1334   Node* find(int idx, bool only_ctrl = false); // Search the graph for the given idx.
1335   Node* find_ctrl(int idx); // Search control ancestors for the given idx.
1336   void dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st, const frame* fr = nullptr) const;
1337   void dump_bfs(const int max_distance, Node* target, const char* options) const; // directly to tty
1338   void dump_bfs(const int max_distance) const; // dump_bfs(max_distance, nullptr, nullptr)
1339   void dump_bfs(const int max_distance, Node* target, const char* options, void* sp, void* fp, void* pc) const;
1340   class DumpConfig {
1341    public:
1342     // overridden to implement coloring of node idx
1343     virtual void pre_dump(outputStream *st, const Node* n) = 0;
1344     virtual void post_dump(outputStream *st) = 0;
1345   };
1346   void dump_idx(bool align = false, outputStream* st = tty, DumpConfig* dc = nullptr) const;
1347   void dump_name(outputStream* st = tty, DumpConfig* dc = nullptr) const;
1348   void dump() const; // print node with newline
1349   void dump(const char* suffix, bool mark = false, outputStream* st = tty, DumpConfig* dc = nullptr) const; // Print this node.
1350   void dump(int depth) const;        // Print this node, recursively to depth d
1351   void dump_ctrl(int depth) const;   // Print control nodes, to depth d
1352   void dump_comp() const;            // Print this node in compact representation.
1353   // Print this node in compact representation.
1354   void dump_comp(const char* suffix, outputStream *st = tty) const;
1355  private:
1356   virtual void dump_req(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print required-edge info
1357   virtual void dump_prec(outputStream* st = tty, DumpConfig* dc = nullptr) const;   // Print precedence-edge info
1358   virtual void dump_out(outputStream* st = tty, DumpConfig* dc = nullptr) const;    // Print the output edge info
1359  public:
1360   virtual void dump_spec(outputStream *st) const {};      // Print per-node info
1361   // Print compact per-node info
1362   virtual void dump_compact_spec(outputStream *st) const { dump_spec(st); }
1363 
1364   static void verify(int verify_depth, VectorSet& visited, Node_List& worklist);
1365 
1366   // This call defines a class-unique string used to identify class instances
1367   virtual const char *Name() const;
1368 
1369   void dump_format(PhaseRegAlloc *ra) const; // debug access to MachNode::format(...)
1370   static bool in_dump() { return Compile::current()->_in_dump_cnt > 0; } // check if we are in a dump call
1371 #endif
1372 #ifdef ASSERT
1373   void verify_construction();
1374   bool verify_jvms(const JVMState* jvms) const;
1375 
1376   Node* _debug_orig;                   // Original version of this, if any.
1377   Node*  debug_orig() const            { return _debug_orig; }
1378   void   set_debug_orig(Node* orig);   // _debug_orig = orig
1379   void   dump_orig(outputStream *st, bool print_key = true) const;
1380 
1381   uint64_t _debug_idx;                 // Unique value assigned to every node.
1382   uint64_t debug_idx() const           { return _debug_idx; }
1383   void set_debug_idx(uint64_t debug_idx) { _debug_idx = debug_idx; }
1384 
1385   int        _hash_lock;               // Barrier to modifications of nodes in the hash table
1386   void  enter_hash_lock() { ++_hash_lock; assert(_hash_lock < 99, "in too many hash tables?"); }
1387   void   exit_hash_lock() { --_hash_lock; assert(_hash_lock >= 0, "mispaired hash locks"); }
1388 
1389   static void init_NodeProperty();
1390 
1391   #if OPTO_DU_ITERATOR_ASSERT
1392   const Node* _last_del;               // The last deleted node.
1393   uint        _del_tick;               // Bumped when a deletion happens..
1394   #endif
1395 #endif
1396 };
1397 
1398 inline bool not_a_node(const Node* n) {
1399   if (n == nullptr)                return true;
1400   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
1401   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
1402   return false;
1403 }
1404 
1405 //-----------------------------------------------------------------------------
1406 // Iterators over DU info, and associated Node functions.
1407 
1408 #if OPTO_DU_ITERATOR_ASSERT
1409 
1410 // Common code for assertion checking on DU iterators.
1411 class DUIterator_Common {
1412 #ifdef ASSERT
1413  protected:
1414   bool         _vdui;               // cached value of VerifyDUIterators
1415   const Node*  _node;               // the node containing the _out array
1416   uint         _outcnt;             // cached node->_outcnt
1417   uint         _del_tick;           // cached node->_del_tick
1418   Node*        _last;               // last value produced by the iterator
1419 
1420   void sample(const Node* node);    // used by c'tor to set up for verifies
1421   void verify(const Node* node, bool at_end_ok = false);
1422   void verify_resync();
1423   void reset(const DUIterator_Common& that);
1424 
1425 // The VDUI_ONLY macro protects code conditionalized on VerifyDUIterators
1426   #define I_VDUI_ONLY(i,x) { if ((i)._vdui) { x; } }
1427 #else
1428   #define I_VDUI_ONLY(i,x) { }
1429 #endif //ASSERT
1430 };
1431 
1432 #define VDUI_ONLY(x)     I_VDUI_ONLY(*this, x)
1433 
1434 // Default DU iterator.  Allows appends onto the out array.
1435 // Allows deletion from the out array only at the current point.
1436 // Usage:
1437 //  for (DUIterator i = x->outs(); x->has_out(i); i++) {
1438 //    Node* y = x->out(i);
1439 //    ...
1440 //  }
1441 // Compiles in product mode to a unsigned integer index, which indexes
1442 // onto a repeatedly reloaded base pointer of x->_out.  The loop predicate
1443 // also reloads x->_outcnt.  If you delete, you must perform "--i" just
1444 // before continuing the loop.  You must delete only the last-produced
1445 // edge.  You must delete only a single copy of the last-produced edge,
1446 // or else you must delete all copies at once (the first time the edge
1447 // is produced by the iterator).
1448 class DUIterator : public DUIterator_Common {
1449   friend class Node;
1450 
1451   // This is the index which provides the product-mode behavior.
1452   // Whatever the product-mode version of the system does to the
1453   // DUI index is done to this index.  All other fields in
1454   // this class are used only for assertion checking.
1455   uint         _idx;
1456 
1457   #ifdef ASSERT
1458   uint         _refresh_tick;    // Records the refresh activity.
1459 
1460   void sample(const Node* node); // Initialize _refresh_tick etc.
1461   void verify(const Node* node, bool at_end_ok = false);
1462   void verify_increment();       // Verify an increment operation.
1463   void verify_resync();          // Verify that we can back up over a deletion.
1464   void verify_finish();          // Verify that the loop terminated properly.
1465   void refresh();                // Resample verification info.
1466   void reset(const DUIterator& that);  // Resample after assignment.
1467   #endif
1468 
1469   DUIterator(const Node* node, int dummy_to_avoid_conversion)
1470     { _idx = 0;                         DEBUG_ONLY(sample(node)); }
1471 
1472  public:
1473   // initialize to garbage; clear _vdui to disable asserts
1474   DUIterator()
1475     { /*initialize to garbage*/         DEBUG_ONLY(_vdui = false); }
1476 
1477   DUIterator(const DUIterator& that)
1478     { _idx = that._idx;                 DEBUG_ONLY(_vdui = false; reset(that)); }
1479 
1480   void operator++(int dummy_to_specify_postfix_op)
1481     { _idx++;                           VDUI_ONLY(verify_increment()); }
1482 
1483   void operator--()
1484     { VDUI_ONLY(verify_resync());       --_idx; }
1485 
1486   ~DUIterator()
1487     { VDUI_ONLY(verify_finish()); }
1488 
1489   void operator=(const DUIterator& that)
1490     { _idx = that._idx;                 DEBUG_ONLY(reset(that)); }
1491 };
1492 
1493 DUIterator Node::outs() const
1494   { return DUIterator(this, 0); }
1495 DUIterator& Node::refresh_out_pos(DUIterator& i) const
1496   { I_VDUI_ONLY(i, i.refresh());        return i; }
1497 bool Node::has_out(DUIterator& i) const
1498   { I_VDUI_ONLY(i, i.verify(this,true));return i._idx < _outcnt; }
1499 Node*    Node::out(DUIterator& i) const
1500   { I_VDUI_ONLY(i, i.verify(this));     return DEBUG_ONLY(i._last=) _out[i._idx]; }
1501 
1502 
1503 // Faster DU iterator.  Disallows insertions into the out array.
1504 // Allows deletion from the out array only at the current point.
1505 // Usage:
1506 //  for (DUIterator_Fast imax, i = x->fast_outs(imax); i < imax; i++) {
1507 //    Node* y = x->fast_out(i);
1508 //    ...
1509 //  }
1510 // Compiles in product mode to raw Node** pointer arithmetic, with
1511 // no reloading of pointers from the original node x.  If you delete,
1512 // you must perform "--i; --imax" just before continuing the loop.
1513 // If you delete multiple copies of the same edge, you must decrement
1514 // imax, but not i, multiple times:  "--i, imax -= num_edges".
1515 class DUIterator_Fast : public DUIterator_Common {
1516   friend class Node;
1517   friend class DUIterator_Last;
1518 
1519   // This is the pointer which provides the product-mode behavior.
1520   // Whatever the product-mode version of the system does to the
1521   // DUI pointer is done to this pointer.  All other fields in
1522   // this class are used only for assertion checking.
1523   Node**       _outp;
1524 
1525   #ifdef ASSERT
1526   void verify(const Node* node, bool at_end_ok = false);
1527   void verify_limit();
1528   void verify_resync();
1529   void verify_relimit(uint n);
1530   void reset(const DUIterator_Fast& that);
1531   #endif
1532 
1533   // Note:  offset must be signed, since -1 is sometimes passed
1534   DUIterator_Fast(const Node* node, ptrdiff_t offset)
1535     { _outp = node->_out + offset;      DEBUG_ONLY(sample(node)); }
1536 
1537  public:
1538   // initialize to garbage; clear _vdui to disable asserts
1539   DUIterator_Fast()
1540     { /*initialize to garbage*/         DEBUG_ONLY(_vdui = false); }
1541 
1542   DUIterator_Fast(const DUIterator_Fast& that)
1543     { _outp = that._outp;               DEBUG_ONLY(_vdui = false; reset(that)); }
1544 
1545   void operator++(int dummy_to_specify_postfix_op)
1546     { _outp++;                          VDUI_ONLY(verify(_node, true)); }
1547 
1548   void operator--()
1549     { VDUI_ONLY(verify_resync());       --_outp; }
1550 
1551   void operator-=(uint n)   // applied to the limit only
1552     { _outp -= n;           VDUI_ONLY(verify_relimit(n));  }
1553 
1554   bool operator<(DUIterator_Fast& limit) {
1555     I_VDUI_ONLY(*this, this->verify(_node, true));
1556     I_VDUI_ONLY(limit, limit.verify_limit());
1557     return _outp < limit._outp;
1558   }
1559 
1560   void operator=(const DUIterator_Fast& that)
1561     { _outp = that._outp;               DEBUG_ONLY(reset(that)); }
1562 };
1563 
1564 DUIterator_Fast Node::fast_outs(DUIterator_Fast& imax) const {
1565   // Assign a limit pointer to the reference argument:
1566   imax = DUIterator_Fast(this, (ptrdiff_t)_outcnt);
1567   // Return the base pointer:
1568   return DUIterator_Fast(this, 0);
1569 }
1570 Node* Node::fast_out(DUIterator_Fast& i) const {
1571   I_VDUI_ONLY(i, i.verify(this));
1572   return DEBUG_ONLY(i._last=) *i._outp;
1573 }
1574 
1575 
1576 // Faster DU iterator.  Requires each successive edge to be removed.
1577 // Does not allow insertion of any edges.
1578 // Usage:
1579 //  for (DUIterator_Last imin, i = x->last_outs(imin); i >= imin; i -= num_edges) {
1580 //    Node* y = x->last_out(i);
1581 //    ...
1582 //  }
1583 // Compiles in product mode to raw Node** pointer arithmetic, with
1584 // no reloading of pointers from the original node x.
1585 class DUIterator_Last : private DUIterator_Fast {
1586   friend class Node;
1587 
1588   #ifdef ASSERT
1589   void verify(const Node* node, bool at_end_ok = false);
1590   void verify_limit();
1591   void verify_step(uint num_edges);
1592   #endif
1593 
1594   // Note:  offset must be signed, since -1 is sometimes passed
1595   DUIterator_Last(const Node* node, ptrdiff_t offset)
1596     : DUIterator_Fast(node, offset) { }
1597 
1598   void operator++(int dummy_to_specify_postfix_op) {} // do not use
1599   void operator<(int)                              {} // do not use
1600 
1601  public:
1602   DUIterator_Last() { }
1603   // initialize to garbage
1604 
1605   DUIterator_Last(const DUIterator_Last& that) = default;
1606 
1607   void operator--()
1608     { _outp--;              VDUI_ONLY(verify_step(1));  }
1609 
1610   void operator-=(uint n)
1611     { _outp -= n;           VDUI_ONLY(verify_step(n));  }
1612 
1613   bool operator>=(DUIterator_Last& limit) {
1614     I_VDUI_ONLY(*this, this->verify(_node, true));
1615     I_VDUI_ONLY(limit, limit.verify_limit());
1616     return _outp >= limit._outp;
1617   }
1618 
1619   DUIterator_Last& operator=(const DUIterator_Last& that) = default;
1620 };
1621 
1622 DUIterator_Last Node::last_outs(DUIterator_Last& imin) const {
1623   // Assign a limit pointer to the reference argument:
1624   imin = DUIterator_Last(this, 0);
1625   // Return the initial pointer:
1626   return DUIterator_Last(this, (ptrdiff_t)_outcnt - 1);
1627 }
1628 Node* Node::last_out(DUIterator_Last& i) const {
1629   I_VDUI_ONLY(i, i.verify(this));
1630   return DEBUG_ONLY(i._last=) *i._outp;
1631 }
1632 
1633 #endif //OPTO_DU_ITERATOR_ASSERT
1634 
1635 #undef I_VDUI_ONLY
1636 #undef VDUI_ONLY
1637 
1638 // An Iterator that truly follows the iterator pattern.  Doesn't
1639 // support deletion but could be made to.
1640 //
1641 //   for (SimpleDUIterator i(n); i.has_next(); i.next()) {
1642 //     Node* m = i.get();
1643 //
1644 class SimpleDUIterator : public StackObj {
1645  private:
1646   Node* node;
1647   DUIterator_Fast imax;
1648   DUIterator_Fast i;
1649  public:
1650   SimpleDUIterator(Node* n): node(n), i(n->fast_outs(imax)) {}
1651   bool has_next() { return i < imax; }
1652   void next() { i++; }
1653   Node* get() { return node->fast_out(i); }
1654 };
1655 
1656 
1657 //-----------------------------------------------------------------------------
1658 // Map dense integer indices to Nodes.  Uses classic doubling-array trick.
1659 // Abstractly provides an infinite array of Node*'s, initialized to null.
1660 // Note that the constructor just zeros things, and since I use Arena
1661 // allocation I do not need a destructor to reclaim storage.
1662 class Node_Array : public AnyObj {
1663 protected:
1664   Arena* _a;                    // Arena to allocate in
1665   uint   _max;
1666   Node** _nodes;
1667   ReallocMark _nesting;         // Safety checks for arena reallocation
1668 
1669   // Grow array to required capacity
1670   void maybe_grow(uint i) {
1671     _nesting.check(_a); // Check if a potential reallocation in the arena is safe
1672     if (i >= _max) {
1673       grow(i);
1674     }
1675   }
1676   void grow(uint i);
1677 
1678 public:
1679   Node_Array(Arena* a, uint max = OptoNodeListSize) : _a(a), _max(max) {
1680     _nodes = NEW_ARENA_ARRAY(a, Node*, max);
1681     clear();
1682   }
1683   Node_Array() : Node_Array(Thread::current()->resource_area()) {}
1684 
1685   NONCOPYABLE(Node_Array);
1686   Node_Array& operator=(Node_Array&&) = delete;
1687   // Allow move constructor for && (eg. capture return of function)
1688   Node_Array(Node_Array&&) = default;
1689 
1690   Node *operator[] ( uint i ) const // Lookup, or null for not mapped
1691   { return (i<_max) ? _nodes[i] : (Node*)nullptr; }
1692   Node* at(uint i) const { assert(i<_max,"oob"); return _nodes[i]; }
1693   Node** adr() { return _nodes; }
1694   // Extend the mapping: index i maps to Node *n.
1695   void map( uint i, Node *n ) { maybe_grow(i); _nodes[i] = n; }
1696   void insert( uint i, Node *n );
1697   void remove( uint i );        // Remove, preserving order
1698   // Clear all entries in _nodes to null but keep storage
1699   void clear() {
1700     Copy::zero_to_bytes(_nodes, _max * sizeof(Node*));
1701   }
1702 
1703   uint max() const { return _max; }
1704   void dump() const;
1705 };
1706 
1707 class Node_List : public Node_Array {
1708   uint _cnt;
1709 public:
1710   Node_List(uint max = OptoNodeListSize) : Node_Array(Thread::current()->resource_area(), max), _cnt(0) {}
1711   Node_List(Arena *a, uint max = OptoNodeListSize) : Node_Array(a, max), _cnt(0) {}
1712 
1713   NONCOPYABLE(Node_List);
1714   Node_List& operator=(Node_List&&) = delete;
1715   // Allow move constructor for && (eg. capture return of function)
1716   Node_List(Node_List&&) = default;
1717 
1718   bool contains(const Node* n) const {
1719     for (uint e = 0; e < size(); e++) {
1720       if (at(e) == n) return true;
1721     }
1722     return false;
1723   }
1724   void insert( uint i, Node *n ) { Node_Array::insert(i,n); _cnt++; }
1725   void remove( uint i ) { Node_Array::remove(i); _cnt--; }
1726   void push( Node *b ) { map(_cnt++,b); }
1727   void yank( Node *n );         // Find and remove
1728   Node *pop() { return _nodes[--_cnt]; }
1729   void clear() { _cnt = 0; Node_Array::clear(); } // retain storage
1730   void copy(const Node_List& from) {
1731     if (from._max > _max) {
1732       grow(from._max);
1733     }
1734     _cnt = from._cnt;
1735     Copy::conjoint_words_to_higher((HeapWord*)&from._nodes[0], (HeapWord*)&_nodes[0], from._max * sizeof(Node*));
1736   }
1737 
1738   uint size() const { return _cnt; }
1739   void dump() const;
1740   void dump_simple() const;
1741 };
1742 
1743 // Definition must appear after complete type definition of Node_List
1744 template <typename Callback, typename Check>
1745 void Node::visit_uses(Callback callback, Check is_boundary) const {
1746   ResourceMark rm;
1747   VectorSet visited;
1748   Node_List worklist;
1749 
1750   // The initial worklist consists of the direct uses
1751   for (DUIterator_Fast kmax, k = fast_outs(kmax); k < kmax; k++) {
1752     Node* out = fast_out(k);
1753     if (!visited.test_set(out->_idx)) { worklist.push(out); }
1754   }
1755 
1756   while (worklist.size() > 0) {
1757     Node* use = worklist.pop();
1758     // Apply callback on boundary nodes
1759     if (is_boundary(use)) {
1760       callback(use);
1761     } else {
1762       // Not a boundary node, continue search
1763       for (DUIterator_Fast kmax, k = use->fast_outs(kmax); k < kmax; k++) {
1764         Node* out = use->fast_out(k);
1765         if (!visited.test_set(out->_idx)) { worklist.push(out); }
1766       }
1767     }
1768   }
1769 }
1770 
1771 
1772 //------------------------------Unique_Node_List-------------------------------
1773 class Unique_Node_List : public Node_List {
1774   VectorSet _in_worklist;
1775   uint _clock_index;            // Index in list where to pop from next
1776 public:
1777   Unique_Node_List() : Node_List(), _clock_index(0) {}
1778   Unique_Node_List(Arena *a) : Node_List(a), _in_worklist(a), _clock_index(0) {}
1779 
1780   NONCOPYABLE(Unique_Node_List);
1781   Unique_Node_List& operator=(Unique_Node_List&&) = delete;
1782   // Allow move constructor for && (eg. capture return of function)
1783   Unique_Node_List(Unique_Node_List&&) = default;
1784 
1785   void remove( Node *n );
1786   bool member(const Node* n) const { return _in_worklist.test(n->_idx) != 0; }
1787   VectorSet& member_set(){ return _in_worklist; }
1788 
1789   void push(Node* b) {
1790     if( !_in_worklist.test_set(b->_idx) )
1791       Node_List::push(b);
1792   }
1793   void push_non_cfg_inputs_of(const Node* node) {
1794     for (uint i = 1; i < node->req(); i++) {
1795       Node* input = node->in(i);
1796       if (input != nullptr && !input->is_CFG()) {
1797         push(input);
1798       }
1799     }
1800   }
1801 
1802   void push_outputs_of(const Node* node) {
1803     for (DUIterator_Fast imax, i = node->fast_outs(imax); i < imax; i++) {
1804       Node* output = node->fast_out(i);
1805       push(output);
1806     }
1807   }
1808 
1809   Node *pop() {
1810     if( _clock_index >= size() ) _clock_index = 0;
1811     Node *b = at(_clock_index);
1812     map( _clock_index, Node_List::pop());
1813     if (size() != 0) _clock_index++; // Always start from 0
1814     _in_worklist.remove(b->_idx);
1815     return b;
1816   }
1817   Node *remove(uint i) {
1818     Node *b = Node_List::at(i);
1819     _in_worklist.remove(b->_idx);
1820     map(i,Node_List::pop());
1821     return b;
1822   }
1823   void yank(Node *n) {
1824     _in_worklist.remove(n->_idx);
1825     Node_List::yank(n);
1826   }
1827   void  clear() {
1828     _in_worklist.clear();        // Discards storage but grows automatically
1829     Node_List::clear();
1830     _clock_index = 0;
1831   }
1832   void ensure_empty() {
1833     assert(size() == 0, "must be empty");
1834     clear(); // just in case
1835   }
1836 
1837   // Used after parsing to remove useless nodes before Iterative GVN
1838   void remove_useless_nodes(VectorSet& useful);
1839 
1840   // If the idx of the Nodes change, we must recompute the VectorSet
1841   void recompute_idx_set() {
1842     _in_worklist.clear();
1843     for (uint i = 0; i < size(); i++) {
1844       Node* n = at(i);
1845       _in_worklist.set(n->_idx);
1846     }
1847   }
1848 
1849 #ifdef ASSERT
1850   bool is_subset_of(Unique_Node_List& other) {
1851     for (uint i = 0; i < size(); i++) {
1852       Node* n = at(i);
1853       if (!other.member(n)) {
1854         return false;
1855       }
1856     }
1857     return true;
1858   }
1859 #endif
1860 
1861   bool contains(const Node* n) const {
1862     fatal("use faster member() instead");
1863     return false;
1864   }
1865 
1866 #ifndef PRODUCT
1867   void print_set() const { _in_worklist.print(); }
1868 #endif
1869 };
1870 
1871 // Unique_Mixed_Node_List
1872 // unique: nodes are added only once
1873 // mixed: allow new and old nodes
1874 class Unique_Mixed_Node_List : public ResourceObj {
1875 public:
1876   Unique_Mixed_Node_List() : _visited_set(cmpkey, hashkey) {}
1877 
1878   void add(Node* node) {
1879     if (not_a_node(node)) {
1880       return; // Gracefully handle null, -1, 0xabababab, etc.
1881     }
1882     if (_visited_set[node] == nullptr) {
1883       _visited_set.Insert(node, node);
1884       _worklist.push(node);
1885     }
1886   }
1887 
1888   Node* operator[] (uint i) const {
1889     return _worklist[i];
1890   }
1891 
1892   size_t size() {
1893     return _worklist.size();
1894   }
1895 
1896 private:
1897   Dict _visited_set;
1898   Node_List _worklist;
1899 };
1900 
1901 // Inline definition of Compile::record_for_igvn must be deferred to this point.
1902 inline void Compile::record_for_igvn(Node* n) {
1903   _igvn_worklist->push(n);
1904 }
1905 
1906 // Inline definition of Compile::remove_for_igvn must be deferred to this point.
1907 inline void Compile::remove_for_igvn(Node* n) {
1908   _igvn_worklist->remove(n);
1909 }
1910 
1911 //------------------------------Node_Stack-------------------------------------
1912 class Node_Stack {
1913 protected:
1914   struct INode {
1915     Node *node; // Processed node
1916     uint  indx; // Index of next node's child
1917   };
1918   INode *_inode_top; // tos, stack grows up
1919   INode *_inode_max; // End of _inodes == _inodes + _max
1920   INode *_inodes;    // Array storage for the stack
1921   Arena *_a;         // Arena to allocate in
1922   ReallocMark _nesting; // Safety checks for arena reallocation
1923 
1924   void maybe_grow() {
1925     _nesting.check(_a); // Check if a potential reallocation in the arena is safe
1926     if (_inode_top >= _inode_max) {
1927       grow();
1928     }
1929   }
1930   void grow();
1931 
1932 public:
1933   Node_Stack(int size) {
1934     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1935     _a = Thread::current()->resource_area();
1936     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1937     _inode_max = _inodes + max;
1938     _inode_top = _inodes - 1; // stack is empty
1939   }
1940 
1941   Node_Stack(Arena *a, int size) : _a(a) {
1942     size_t max = (size > OptoNodeListSize) ? size : OptoNodeListSize;
1943     _inodes = NEW_ARENA_ARRAY( _a, INode, max );
1944     _inode_max = _inodes + max;
1945     _inode_top = _inodes - 1; // stack is empty
1946   }
1947 
1948   void pop() {
1949     assert(_inode_top >= _inodes, "node stack underflow");
1950     --_inode_top;
1951   }
1952   void push(Node *n, uint i) {
1953     ++_inode_top;
1954     maybe_grow();
1955     INode *top = _inode_top; // optimization
1956     top->node = n;
1957     top->indx = i;
1958   }
1959   Node *node() const {
1960     return _inode_top->node;
1961   }
1962   Node* node_at(uint i) const {
1963     assert(_inodes + i <= _inode_top, "in range");
1964     return _inodes[i].node;
1965   }
1966   uint index() const {
1967     return _inode_top->indx;
1968   }
1969   uint index_at(uint i) const {
1970     assert(_inodes + i <= _inode_top, "in range");
1971     return _inodes[i].indx;
1972   }
1973   void set_node(Node *n) {
1974     _inode_top->node = n;
1975   }
1976   void set_index(uint i) {
1977     _inode_top->indx = i;
1978   }
1979   uint size_max() const { return (uint)pointer_delta(_inode_max, _inodes,  sizeof(INode)); } // Max size
1980   uint size() const { return (uint)pointer_delta((_inode_top+1), _inodes,  sizeof(INode)); } // Current size
1981   bool is_nonempty() const { return (_inode_top >= _inodes); }
1982   bool is_empty() const { return (_inode_top < _inodes); }
1983   void clear() { _inode_top = _inodes - 1; } // retain storage
1984 
1985   // Node_Stack is used to map nodes.
1986   Node* find(uint idx) const;
1987 
1988   NONCOPYABLE(Node_Stack);
1989 };
1990 
1991 
1992 //-----------------------------Node_Notes--------------------------------------
1993 // Debugging or profiling annotations loosely and sparsely associated
1994 // with some nodes.  See Compile::node_notes_at for the accessor.
1995 class Node_Notes {
1996   JVMState* _jvms;
1997 
1998 public:
1999   Node_Notes(JVMState* jvms = nullptr) {
2000     _jvms = jvms;
2001   }
2002 
2003   JVMState* jvms()            { return _jvms; }
2004   void  set_jvms(JVMState* x) {        _jvms = x; }
2005 
2006   // True if there is nothing here.
2007   bool is_clear() {
2008     return (_jvms == nullptr);
2009   }
2010 
2011   // Make there be nothing here.
2012   void clear() {
2013     _jvms = nullptr;
2014   }
2015 
2016   // Make a new, clean node notes.
2017   static Node_Notes* make(Compile* C) {
2018     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
2019     nn->clear();
2020     return nn;
2021   }
2022 
2023   Node_Notes* clone(Compile* C) {
2024     Node_Notes* nn = NEW_ARENA_ARRAY(C->comp_arena(), Node_Notes, 1);
2025     (*nn) = (*this);
2026     return nn;
2027   }
2028 
2029   // Absorb any information from source.
2030   bool update_from(Node_Notes* source) {
2031     bool changed = false;
2032     if (source != nullptr) {
2033       if (source->jvms() != nullptr) {
2034         set_jvms(source->jvms());
2035         changed = true;
2036       }
2037     }
2038     return changed;
2039   }
2040 };
2041 
2042 // Inlined accessors for Compile::node_nodes that require the preceding class:
2043 inline Node_Notes*
2044 Compile::locate_node_notes(GrowableArray<Node_Notes*>* arr,
2045                            int idx, bool can_grow) {
2046   assert(idx >= 0, "oob");
2047   int block_idx = (idx >> _log2_node_notes_block_size);
2048   int grow_by = (block_idx - (arr == nullptr? 0: arr->length()));
2049   if (grow_by >= 0) {
2050     if (!can_grow) return nullptr;
2051     grow_node_notes(arr, grow_by + 1);
2052   }
2053   if (arr == nullptr) return nullptr;
2054   // (Every element of arr is a sub-array of length _node_notes_block_size.)
2055   return arr->at(block_idx) + (idx & (_node_notes_block_size-1));
2056 }
2057 
2058 inline Node_Notes* Compile::node_notes_at(int idx) {
2059   return locate_node_notes(_node_note_array, idx, false);
2060 }
2061 
2062 inline bool
2063 Compile::set_node_notes_at(int idx, Node_Notes* value) {
2064   if (value == nullptr || value->is_clear())
2065     return false;  // nothing to write => write nothing
2066   Node_Notes* loc = locate_node_notes(_node_note_array, idx, true);
2067   assert(loc != nullptr, "");
2068   return loc->update_from(value);
2069 }
2070 
2071 
2072 //------------------------------TypeNode---------------------------------------
2073 // Node with a Type constant.
2074 class TypeNode : public Node {
2075 protected:
2076   virtual uint hash() const;    // Check the type
2077   virtual bool cmp( const Node &n ) const;
2078   virtual uint size_of() const; // Size is bigger
2079   const Type* const _type;
2080 public:
2081   void set_type(const Type* t) {
2082     assert(t != nullptr, "sanity");
2083     DEBUG_ONLY(uint check_hash = (VerifyHashTableKeys && _hash_lock) ? hash() : NO_HASH);
2084     *(const Type**)&_type = t;   // cast away const-ness
2085     // If this node is in the hash table, make sure it doesn't need a rehash.
2086     assert(check_hash == NO_HASH || check_hash == hash(), "type change must preserve hash code");
2087   }
2088   const Type* type() const { assert(_type != nullptr, "sanity"); return _type; };
2089   TypeNode( const Type *t, uint required ) : Node(required), _type(t) {
2090     init_class_id(Class_Type);
2091   }
2092   virtual const Type* Value(PhaseGVN* phase) const;
2093   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
2094   virtual const Type *bottom_type() const;
2095   virtual       uint  ideal_reg() const;
2096 
2097   void make_path_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, Node* ctrl_use, uint j, const char* phase_str);
2098 #ifndef PRODUCT
2099   virtual void dump_spec(outputStream *st) const;
2100   virtual void dump_compact_spec(outputStream *st) const;
2101 #endif
2102   void make_paths_from_here_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, const char* phase_str);
2103   void create_halt_path(PhaseIterGVN* igvn, Node* c, PhaseIdealLoop* loop, const char* phase_str) const;
2104 };
2105 
2106 #include "opto/opcodes.hpp"
2107 
2108 #define Op_IL(op) \
2109   inline int Op_ ## op(BasicType bt) { \
2110   assert(bt == T_INT || bt == T_LONG, "only for int or longs"); \
2111   if (bt == T_INT) { \
2112     return Op_## op ## I; \
2113   } \
2114   return Op_## op ## L; \
2115 }
2116 
2117 Op_IL(Add)
2118 Op_IL(And)
2119 Op_IL(Sub)
2120 Op_IL(Mul)
2121 Op_IL(URShift)
2122 Op_IL(LShift)
2123 Op_IL(RShift)
2124 Op_IL(Xor)
2125 Op_IL(Cmp)
2126 Op_IL(Div)
2127 Op_IL(Mod)
2128 Op_IL(UDiv)
2129 Op_IL(UMod)
2130 
2131 inline int Op_ConIL(BasicType bt) {
2132   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2133   if (bt == T_INT) {
2134     return Op_ConI;
2135   }
2136   return Op_ConL;
2137 }
2138 
2139 inline int Op_Cmp_unsigned(BasicType bt) {
2140   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2141   if (bt == T_INT) {
2142     return Op_CmpU;
2143   }
2144   return Op_CmpUL;
2145 }
2146 
2147 inline int Op_Cast(BasicType bt) {
2148   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2149   if (bt == T_INT) {
2150     return Op_CastII;
2151   }
2152   return Op_CastLL;
2153 }
2154 
2155 inline int Op_DivIL(BasicType bt, bool is_unsigned) {
2156   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2157   if (bt == T_INT) {
2158     if (is_unsigned) {
2159       return Op_UDivI;
2160     } else {
2161       return Op_DivI;
2162     }
2163   }
2164   if (is_unsigned) {
2165     return Op_UDivL;
2166   } else {
2167     return Op_DivL;
2168   }
2169 }
2170 
2171 inline int Op_DivModIL(BasicType bt, bool is_unsigned) {
2172   assert(bt == T_INT || bt == T_LONG, "only for int or longs");
2173   if (bt == T_INT) {
2174     if (is_unsigned) {
2175       return Op_UDivModI;
2176     } else {
2177       return Op_DivModI;
2178     }
2179   }
2180   if (is_unsigned) {
2181     return Op_UDivModL;
2182   } else {
2183     return Op_DivModL;
2184   }
2185 }
2186 
2187 // Interface to define actions that should be taken when running DataNodeBFS. Each use can extend this class to specify
2188 // a customized BFS.
2189 class BFSActions : public StackObj {
2190  public:
2191   // Should a node's inputs further be visited in the BFS traversal? By default, we visit all data inputs. Override this
2192   // method to provide a custom filter.
2193   virtual bool should_visit(Node* node) const {
2194     // By default, visit all inputs.
2195     return true;
2196   };
2197 
2198   // Is the visited node a target node that we are looking for in the BFS traversal? We do not visit its inputs further
2199   // but the BFS will continue to visit all unvisited nodes in the queue.
2200   virtual bool is_target_node(Node* node) const = 0;
2201 
2202   // Defines an action that should be taken when we visit a target node in the BFS traversal.
2203   // To give more freedom, we pass the direct child node to the target node such that
2204   // child->in(i) == target node. This allows to also directly replace the target node instead
2205   // of only updating its inputs.
2206   virtual void target_node_action(Node* child, uint i) = 0;
2207 };
2208 
2209 // Class to perform a BFS traversal on the data nodes from a given start node. The provided BFSActions guide which
2210 // data node's inputs should be further visited, which data nodes are target nodes and what to do with the target nodes.
2211 class DataNodeBFS : public StackObj {
2212   BFSActions& _bfs_actions;
2213 
2214  public:
2215   explicit DataNodeBFS(BFSActions& bfs_action) : _bfs_actions(bfs_action) {}
2216 
2217   // Run the BFS starting from 'start_node' and apply the actions provided to this class.
2218   void run(Node* start_node) {
2219     ResourceMark rm;
2220     Unique_Node_List _nodes_to_visit;
2221     _nodes_to_visit.push(start_node);
2222     for (uint i = 0; i < _nodes_to_visit.size(); i++) {
2223       Node* next = _nodes_to_visit[i];
2224       for (uint j = 1; j < next->req(); j++) {
2225         Node* input = next->in(j);
2226         if (_bfs_actions.is_target_node(input)) {
2227           assert(_bfs_actions.should_visit(input), "must also pass node filter");
2228           _bfs_actions.target_node_action(next, j);
2229         } else if (_bfs_actions.should_visit(input)) {
2230           _nodes_to_visit.push(input);
2231         }
2232       }
2233     }
2234   }
2235 };
2236 
2237 #endif // SHARE_OPTO_NODE_HPP