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