1 /* 2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_OPTO_CHAITIN_HPP 26 #define SHARE_VM_OPTO_CHAITIN_HPP 27 28 #include "code/vmreg.hpp" 29 #include "libadt/port.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "opto/connode.hpp" 32 #include "opto/live.hpp" 33 #include "opto/matcher.hpp" 34 #include "opto/phase.hpp" 35 #include "opto/regalloc.hpp" 36 #include "opto/regmask.hpp" 37 38 class LoopTree; 39 class MachCallNode; 40 class MachSafePointNode; 41 class Matcher; 42 class PhaseCFG; 43 class PhaseLive; 44 class PhaseRegAlloc; 45 class PhaseChaitin; 46 47 #define OPTO_DEBUG_SPLIT_FREQ BLOCK_FREQUENCY(0.001) 48 #define OPTO_LRG_HIGH_FREQ BLOCK_FREQUENCY(0.25) 49 50 //------------------------------LRG-------------------------------------------- 51 // Live-RanGe structure. 52 class LRG : public ResourceObj { 53 friend class VMStructs; 54 public: 55 static const uint AllStack_size = 0xFFFFF; // This mask size is used to tell that the mask of this LRG supports stack positions 56 enum { SPILL_REG=29999 }; // Register number of a spilled LRG 57 58 double _cost; // 2 for loads/1 for stores times block freq 59 double _area; // Sum of all simultaneously live values 60 double score() const; // Compute score from cost and area 61 double _maxfreq; // Maximum frequency of any def or use 62 63 Node *_def; // Check for multi-def live ranges 64 #ifndef PRODUCT 65 GrowableArray<Node*>* _defs; 66 #endif 67 68 uint _risk_bias; // Index of LRG which we want to avoid color 69 uint _copy_bias; // Index of LRG which we want to share color 70 71 uint _next; // Index of next LRG in linked list 72 uint _prev; // Index of prev LRG in linked list 73 private: 74 uint _reg; // Chosen register; undefined if mask is plural 75 public: 76 // Return chosen register for this LRG. Error if the LRG is not bound to 77 // a single register. 78 OptoReg::Name reg() const { return OptoReg::Name(_reg); } 79 void set_reg( OptoReg::Name r ) { _reg = r; } 80 81 private: 82 uint _eff_degree; // Effective degree: Sum of neighbors _num_regs 83 public: 84 int degree() const { assert( _degree_valid , "" ); return _eff_degree; } 85 // Degree starts not valid and any change to the IFG neighbor 86 // set makes it not valid. 87 void set_degree( uint degree ) { 88 _eff_degree = degree; 89 debug_only(_degree_valid = 1;) 90 assert(!_mask.is_AllStack() || (_mask.is_AllStack() && lo_degree()), "_eff_degree can't be bigger than AllStack_size - _num_regs if the mask supports stack registers"); 91 } 92 // Made a change that hammered degree 93 void invalid_degree() { debug_only(_degree_valid=0;) } 94 // Incrementally modify degree. If it was correct, it should remain correct 95 void inc_degree( uint mod ) { 96 _eff_degree += mod; 97 assert(!_mask.is_AllStack() || (_mask.is_AllStack() && lo_degree()), "_eff_degree can't be bigger than AllStack_size - _num_regs if the mask supports stack registers"); 98 } 99 // Compute the degree between 2 live ranges 100 int compute_degree( LRG &l ) const; 101 bool mask_is_nonempty_and_up() const { 102 return mask().is_UP() && mask_size(); 103 } 104 bool is_float_or_vector() const { 105 return _is_float || _is_vector; 106 } 107 108 private: 109 RegMask _mask; // Allowed registers for this LRG 110 uint _mask_size; // cache of _mask.Size(); 111 public: 112 int compute_mask_size() const { return _mask.is_AllStack() ? AllStack_size : _mask.Size(); } 113 void set_mask_size( int size ) { 114 assert((size == (int)AllStack_size) || (size == (int)_mask.Size()), ""); 115 _mask_size = size; 116 #ifdef ASSERT 117 _msize_valid=1; 118 if (_is_vector) { 119 assert(!_fat_proj, "sanity"); 120 _mask.verify_sets(_num_regs); 121 } else if (_num_regs == 2 && !_fat_proj) { 122 _mask.verify_pairs(); 123 } 124 #endif 125 } 126 void compute_set_mask_size() { set_mask_size(compute_mask_size()); } 127 int mask_size() const { assert( _msize_valid, "mask size not valid" ); 128 return _mask_size; } 129 // Get the last mask size computed, even if it does not match the 130 // count of bits in the current mask. 131 int get_invalid_mask_size() const { return _mask_size; } 132 const RegMask &mask() const { return _mask; } 133 void set_mask( const RegMask &rm ) { _mask = rm; debug_only(_msize_valid=0;)} 134 void AND( const RegMask &rm ) { _mask.AND(rm); debug_only(_msize_valid=0;)} 135 void SUBTRACT( const RegMask &rm ) { _mask.SUBTRACT(rm); debug_only(_msize_valid=0;)} 136 void Clear() { _mask.Clear() ; debug_only(_msize_valid=1); _mask_size = 0; } 137 void Set_All() { _mask.Set_All(); debug_only(_msize_valid=1); _mask_size = RegMask::CHUNK_SIZE; } 138 139 void Insert( OptoReg::Name reg ) { _mask.Insert(reg); debug_only(_msize_valid=0;) } 140 void Remove( OptoReg::Name reg ) { _mask.Remove(reg); debug_only(_msize_valid=0;) } 141 void clear_to_pairs() { _mask.clear_to_pairs(); debug_only(_msize_valid=0;) } 142 void clear_to_sets() { _mask.clear_to_sets(_num_regs); debug_only(_msize_valid=0;) } 143 144 // Number of registers this live range uses when it colors 145 private: 146 uint8 _num_regs; // 2 for Longs and Doubles, 1 for all else 147 // except _num_regs is kill count for fat_proj 148 public: 149 int num_regs() const { return _num_regs; } 150 void set_num_regs( int reg ) { assert( _num_regs == reg || !_num_regs, "" ); _num_regs = reg; } 151 152 private: 153 // Number of physical registers this live range uses when it colors 154 // Architecture and register-set dependent 155 uint8 _reg_pressure; 156 public: 157 void set_reg_pressure(int i) { _reg_pressure = i; } 158 int reg_pressure() const { return _reg_pressure; } 159 160 // How much 'wiggle room' does this live range have? 161 // How many color choices can it make (scaled by _num_regs)? 162 int degrees_of_freedom() const { return mask_size() - _num_regs; } 163 // Bound LRGs have ZERO degrees of freedom. We also count 164 // must_spill as bound. 165 bool is_bound () const { return _is_bound; } 166 // Negative degrees-of-freedom; even with no neighbors this 167 // live range must spill. 168 bool not_free() const { return degrees_of_freedom() < 0; } 169 // Is this live range of "low-degree"? Trivially colorable? 170 bool lo_degree () const { return degree() <= degrees_of_freedom(); } 171 // Is this live range just barely "low-degree"? Trivially colorable? 172 bool just_lo_degree () const { return degree() == degrees_of_freedom(); } 173 174 uint _is_oop:1, // Live-range holds an oop 175 _is_float:1, // True if in float registers 176 _is_vector:1, // True if in vector registers 177 _was_spilled1:1, // True if prior spilling on def 178 _was_spilled2:1, // True if twice prior spilling on def 179 _is_bound:1, // live range starts life with no 180 // degrees of freedom. 181 _direct_conflict:1, // True if def and use registers in conflict 182 _must_spill:1, // live range has lost all degrees of freedom 183 // If _fat_proj is set, live range does NOT require aligned, adjacent 184 // registers and has NO interferences. 185 // If _fat_proj is clear, live range requires num_regs() to be a power of 186 // 2, and it requires registers to form an aligned, adjacent set. 187 _fat_proj:1, // 188 _was_lo:1, // Was lo-degree prior to coalesce 189 _msize_valid:1, // _mask_size cache valid 190 _degree_valid:1, // _degree cache valid 191 _has_copy:1, // Adjacent to some copy instruction 192 _at_risk:1; // Simplify says this guy is at risk to spill 193 194 195 // Alive if non-zero, dead if zero 196 bool alive() const { return _def != NULL; } 197 bool is_multidef() const { return _def == NodeSentinel; } 198 bool is_singledef() const { return _def != NodeSentinel; } 199 200 #ifndef PRODUCT 201 void dump( ) const; 202 #endif 203 }; 204 205 //------------------------------IFG-------------------------------------------- 206 // InterFerence Graph 207 // An undirected graph implementation. Created with a fixed number of 208 // vertices. Edges can be added & tested. Vertices can be removed, then 209 // added back later with all edges intact. Can add edges between one vertex 210 // and a list of other vertices. Can union vertices (and their edges) 211 // together. The IFG needs to be really really fast, and also fairly 212 // abstract! It needs abstraction so I can fiddle with the implementation to 213 // get even more speed. 214 class PhaseIFG : public Phase { 215 friend class VMStructs; 216 // Current implementation: a triangular adjacency list. 217 218 // Array of adjacency-lists, indexed by live-range number 219 IndexSet *_adjs; 220 221 // Assertion bit for proper use of Squaring 222 bool _is_square; 223 224 // Live range structure goes here 225 LRG *_lrgs; // Array of LRG structures 226 227 public: 228 // Largest live-range number 229 uint _maxlrg; 230 231 Arena *_arena; 232 233 // Keep track of inserted and deleted Nodes 234 VectorSet *_yanked; 235 236 PhaseIFG( Arena *arena ); 237 void init( uint maxlrg ); 238 239 // Add edge between a and b. Returns true if actually addded. 240 int add_edge( uint a, uint b ); 241 242 // Add edge between a and everything in the vector 243 void add_vector( uint a, IndexSet *vec ); 244 245 // Test for edge existance 246 int test_edge( uint a, uint b ) const; 247 248 // Square-up matrix for faster Union 249 void SquareUp(); 250 251 // Return number of LRG neighbors 252 uint neighbor_cnt( uint a ) const { return _adjs[a].count(); } 253 // Union edges of b into a on Squared-up matrix 254 void Union( uint a, uint b ); 255 // Test for edge in Squared-up matrix 256 int test_edge_sq( uint a, uint b ) const; 257 // Yank a Node and all connected edges from the IFG. Be prepared to 258 // re-insert the yanked Node in reverse order of yanking. Return a 259 // list of neighbors (edges) yanked. 260 IndexSet *remove_node( uint a ); 261 // Reinsert a yanked Node 262 void re_insert( uint a ); 263 // Return set of neighbors 264 IndexSet *neighbors( uint a ) const { return &_adjs[a]; } 265 266 #ifndef PRODUCT 267 // Dump the IFG 268 void dump() const; 269 void stats() const; 270 void verify( const PhaseChaitin * ) const; 271 #endif 272 273 //--------------- Live Range Accessors 274 LRG &lrgs(uint idx) const { assert(idx < _maxlrg, "oob"); return _lrgs[idx]; } 275 276 // Compute and set effective degree. Might be folded into SquareUp(). 277 void Compute_Effective_Degree(); 278 279 // Compute effective degree as the sum of neighbors' _sizes. 280 int effective_degree( uint lidx ) const; 281 }; 282 283 // The LiveRangeMap class is responsible for storing node to live range id mapping. 284 // Each node is mapped to a live range id (a virtual register). Nodes that are 285 // not considered for register allocation are given live range id 0. 286 class LiveRangeMap VALUE_OBJ_CLASS_SPEC { 287 288 private: 289 290 uint _max_lrg_id; 291 292 // Union-find map. Declared as a short for speed. 293 // Indexed by live-range number, it returns the compacted live-range number 294 LRG_List _uf_map; 295 296 // Map from Nodes to live ranges 297 LRG_List _names; 298 299 // Straight out of Tarjan's union-find algorithm 300 uint find_compress(const Node *node) { 301 uint lrg_id = find_compress(_names.at(node->_idx)); 302 _names.at_put(node->_idx, lrg_id); 303 return lrg_id; 304 } 305 306 uint find_compress(uint lrg); 307 308 public: 309 310 const LRG_List& names() { 311 return _names; 312 } 313 314 uint max_lrg_id() const { 315 return _max_lrg_id; 316 } 317 318 void set_max_lrg_id(uint max_lrg_id) { 319 _max_lrg_id = max_lrg_id; 320 } 321 322 uint size() const { 323 return _names.length(); 324 } 325 326 uint live_range_id(uint idx) const { 327 return _names.at(idx); 328 } 329 330 uint live_range_id(const Node *node) const { 331 return _names.at(node->_idx); 332 } 333 334 uint uf_live_range_id(uint lrg_id) const { 335 return _uf_map.at(lrg_id); 336 } 337 338 void map(uint idx, uint lrg_id) { 339 _names.at_put(idx, lrg_id); 340 } 341 342 void uf_map(uint dst_lrg_id, uint src_lrg_id) { 343 _uf_map.at_put(dst_lrg_id, src_lrg_id); 344 } 345 346 void extend(uint idx, uint lrg_id) { 347 _names.at_put_grow(idx, lrg_id); 348 } 349 350 void uf_extend(uint dst_lrg_id, uint src_lrg_id) { 351 _uf_map.at_put_grow(dst_lrg_id, src_lrg_id); 352 } 353 354 LiveRangeMap(Arena* arena, uint unique) 355 : _names(arena, unique, unique, 0) 356 , _uf_map(arena, unique, unique, 0) 357 , _max_lrg_id(0) {} 358 359 uint find_id( const Node *n ) { 360 uint retval = live_range_id(n); 361 assert(retval == find(n),"Invalid node to lidx mapping"); 362 return retval; 363 } 364 365 // Reset the Union-Find map to identity 366 void reset_uf_map(uint max_lrg_id); 367 368 // Make all Nodes map directly to their final live range; no need for 369 // the Union-Find mapping after this call. 370 void compress_uf_map_for_nodes(); 371 372 uint find(uint lidx) { 373 uint uf_lidx = _uf_map.at(lidx); 374 return (uf_lidx == lidx) ? uf_lidx : find_compress(lidx); 375 } 376 377 // Convert a Node into a Live Range Index - a lidx 378 uint find(const Node *node) { 379 uint lidx = live_range_id(node); 380 uint uf_lidx = _uf_map.at(lidx); 381 return (uf_lidx == lidx) ? uf_lidx : find_compress(node); 382 } 383 384 // Like Find above, but no path compress, so bad asymptotic behavior 385 uint find_const(uint lrg) const; 386 387 // Like Find above, but no path compress, so bad asymptotic behavior 388 uint find_const(const Node *node) const { 389 if(node->_idx >= (uint)_names.length()) { 390 return 0; // not mapped, usual for debug dump 391 } 392 return find_const(_names.at(node->_idx)); 393 } 394 }; 395 396 //------------------------------Chaitin---------------------------------------- 397 // Briggs-Chaitin style allocation, mostly. 398 class PhaseChaitin : public PhaseRegAlloc { 399 friend class VMStructs; 400 401 int _trip_cnt; 402 int _alternate; 403 404 LRG &lrgs(uint idx) const { return _ifg->lrgs(idx); } 405 PhaseLive *_live; // Liveness, used in the interference graph 406 PhaseIFG *_ifg; // Interference graph (for original chunk) 407 Node_List **_lrg_nodes; // Array of node; lists for lrgs which spill 408 VectorSet _spilled_once; // Nodes that have been spilled 409 VectorSet _spilled_twice; // Nodes that have been spilled twice 410 411 // Combine the Live Range Indices for these 2 Nodes into a single live 412 // range. Future requests for any Node in either live range will 413 // return the live range index for the combined live range. 414 void Union( const Node *src, const Node *dst ); 415 416 void new_lrg( const Node *x, uint lrg ); 417 418 // Compact live ranges, removing unused ones. Return new maxlrg. 419 void compact(); 420 421 uint _lo_degree; // Head of lo-degree LRGs list 422 uint _lo_stk_degree; // Head of lo-stk-degree LRGs list 423 uint _hi_degree; // Head of hi-degree LRGs list 424 uint _simplified; // Linked list head of simplified LRGs 425 426 // Helper functions for Split() 427 uint split_DEF( Node *def, Block *b, int loc, uint max, Node **Reachblock, Node **debug_defs, GrowableArray<uint> splits, int slidx ); 428 uint split_USE( Node *def, Block *b, Node *use, uint useidx, uint max, bool def_down, bool cisc_sp, GrowableArray<uint> splits, int slidx ); 429 430 //------------------------------clone_projs------------------------------------ 431 // After cloning some rematerialized instruction, clone any MachProj's that 432 // follow it. Example: Intel zero is XOR, kills flags. Sparc FP constants 433 // use G3 as an address temp. 434 int clone_projs(Block* b, uint idx, Node* orig, Node* copy, uint& max_lrg_id); 435 436 int clone_projs(Block* b, uint idx, Node* orig, Node* copy, LiveRangeMap& lrg_map) { 437 uint max_lrg_id = lrg_map.max_lrg_id(); 438 int found_projs = clone_projs(b, idx, orig, copy, max_lrg_id); 439 if (found_projs > 0) { 440 // max_lrg_id is updated during call above 441 lrg_map.set_max_lrg_id(max_lrg_id); 442 } 443 return found_projs; 444 } 445 446 Node *split_Rematerialize(Node *def, Block *b, uint insidx, uint &maxlrg, GrowableArray<uint> splits, 447 int slidx, uint *lrg2reach, Node **Reachblock, bool walkThru); 448 // True if lidx is used before any real register is def'd in the block 449 bool prompt_use( Block *b, uint lidx ); 450 Node *get_spillcopy_wide( Node *def, Node *use, uint uidx ); 451 // Insert the spill at chosen location. Skip over any intervening Proj's or 452 // Phis. Skip over a CatchNode and projs, inserting in the fall-through block 453 // instead. Update high-pressure indices. Create a new live range. 454 void insert_proj( Block *b, uint i, Node *spill, uint maxlrg ); 455 456 bool is_high_pressure( Block *b, LRG *lrg, uint insidx ); 457 458 uint _oldphi; // Node index which separates pre-allocation nodes 459 460 Block **_blks; // Array of blocks sorted by frequency for coalescing 461 462 float _high_frequency_lrg; // Frequency at which LRG will be spilled for debug info 463 464 #ifndef PRODUCT 465 bool _trace_spilling; 466 #endif 467 468 public: 469 PhaseChaitin( uint unique, PhaseCFG &cfg, Matcher &matcher ); 470 ~PhaseChaitin() {} 471 472 LiveRangeMap _lrg_map; 473 474 // Do all the real work of allocate 475 void Register_Allocate(); 476 477 float high_frequency_lrg() const { return _high_frequency_lrg; } 478 479 #ifndef PRODUCT 480 bool trace_spilling() const { return _trace_spilling; } 481 #endif 482 483 private: 484 // De-SSA the world. Assign registers to Nodes. Use the same register for 485 // all inputs to a PhiNode, effectively coalescing live ranges. Insert 486 // copies as needed. 487 void de_ssa(); 488 489 // Add edge between reg and everything in the vector. 490 // Same as _ifg->add_vector(reg,live) EXCEPT use the RegMask 491 // information to trim the set of interferences. Return the 492 // count of edges added. 493 void interfere_with_live(uint lid, IndexSet* liveout); 494 #ifdef ASSERT 495 // Count register pressure for asserts 496 uint count_int_pressure(IndexSet* liveout); 497 uint count_float_pressure(IndexSet* liveout); 498 #endif 499 500 // Build the interference graph using virtual registers only. 501 // Used for aggressive coalescing. 502 void build_ifg_virtual( ); 503 504 class Pressure { 505 public: 506 // keeps track of the register pressure at the current 507 // instruction (used when stepping backwards in the block) 508 uint _current_pressure; 509 510 // keeps track of the instruction index of the first low to high register pressure 511 // transition (starting from the top) in the block 512 // if high_pressure_index == 0 then the whole block is high pressure 513 // if high_pressure_index = b.end_idx() + 1 then the whole block is low pressure 514 uint _high_pressure_index; 515 516 // stores the highest pressure we find 517 uint _final_pressure; 518 519 // number of live ranges that constitute high register pressure 520 const uint _high_pressure_limit; 521 522 // lower the register pressure and look for a low to high pressure 523 // transition 524 void lower(LRG& lrg, uint& location) { 525 _current_pressure -= lrg.reg_pressure(); 526 if (_current_pressure == _high_pressure_limit) { 527 _high_pressure_index = location; 528 if (_current_pressure > _final_pressure) { 529 _final_pressure = _current_pressure + 1; 530 } 531 } 532 } 533 534 // raise the pressure and store the pressure if it's the biggest 535 // pressure so far 536 void raise(LRG &lrg) { 537 _current_pressure += lrg.reg_pressure(); 538 if (_current_pressure > _final_pressure) { 539 _final_pressure = _current_pressure; 540 } 541 } 542 543 Pressure(uint high_pressure_index, uint high_pressure_limit) 544 : _current_pressure(0) 545 , _high_pressure_index(high_pressure_index) 546 , _high_pressure_limit(high_pressure_limit) 547 , _final_pressure(0) {} 548 }; 549 550 void lower_pressure(Block* b, uint location, LRG& lrg, IndexSet* liveout, Pressure& int_pressure, Pressure& float_pressure); 551 void raise_pressure(Block* b, LRG& lrg, Pressure& int_pressure, Pressure& float_pressure); 552 void check_for_high_pressure_transition_at_fatproj(uint& block_reg_pressure, uint location, LRG& lrg, Pressure& pressure, const int op_regtype); 553 void add_input_to_liveout(Block* b, Node* n, IndexSet* liveout, double cost, Pressure& int_pressure, Pressure& float_pressure); 554 void compute_initial_block_pressure(Block* b, IndexSet* liveout, Pressure& int_pressure, Pressure& float_pressure, double cost); 555 bool remove_node_if_not_used(Block* b, uint location, Node* n, uint lid, IndexSet* liveout); 556 void assign_high_score_to_immediate_copies(Block* b, Node* n, LRG& lrg, uint next_inst, uint last_inst); 557 void remove_interference_from_copy(Block* b, uint location, uint lid_copy, IndexSet* liveout, double cost, Pressure& int_pressure, Pressure& float_pressure); 558 void remove_bound_register_from_interfering_live_ranges(LRG& lrg, IndexSet* liveout, uint& must_spill); 559 void check_for_high_pressure_block(Pressure& pressure); 560 void adjust_high_pressure_index(Block* b, uint& hrp_index, Pressure& pressure); 561 562 // Build the interference graph using physical registers when available. 563 // That is, if 2 live ranges are simultaneously alive but in their 564 // acceptable register sets do not overlap, then they do not interfere. 565 uint build_ifg_physical( ResourceArea *a ); 566 567 // Gather LiveRanGe information, including register masks and base pointer/ 568 // derived pointer relationships. 569 void gather_lrg_masks( bool mod_cisc_masks ); 570 571 // Force the bases of derived pointers to be alive at GC points. 572 bool stretch_base_pointer_live_ranges( ResourceArea *a ); 573 // Helper to stretch above; recursively discover the base Node for 574 // a given derived Node. Easy for AddP-related machine nodes, but 575 // needs to be recursive for derived Phis. 576 Node *find_base_for_derived( Node **derived_base_map, Node *derived, uint &maxlrg ); 577 578 // Set the was-lo-degree bit. Conservative coalescing should not change the 579 // colorability of the graph. If any live range was of low-degree before 580 // coalescing, it should Simplify. This call sets the was-lo-degree bit. 581 void set_was_low(); 582 583 // Split live-ranges that must spill due to register conflicts (as opposed 584 // to capacity spills). Typically these are things def'd in a register 585 // and used on the stack or vice-versa. 586 void pre_spill(); 587 588 // Init LRG caching of degree, numregs. Init lo_degree list. 589 void cache_lrg_info( ); 590 591 // Simplify the IFG by removing LRGs of low degree with no copies 592 void Pre_Simplify(); 593 594 // Simplify the IFG by removing LRGs of low degree 595 void Simplify(); 596 597 // Select colors by re-inserting edges into the IFG. 598 // Return TRUE if any spills occurred. 599 uint Select( ); 600 // Helper function for select which allows biased coloring 601 OptoReg::Name choose_color( LRG &lrg, int chunk ); 602 // Helper function which implements biasing heuristic 603 OptoReg::Name bias_color( LRG &lrg, int chunk ); 604 605 // Split uncolorable live ranges 606 // Return new number of live ranges 607 uint Split(uint maxlrg, ResourceArea* split_arena); 608 609 // Copy 'was_spilled'-edness from one Node to another. 610 void copy_was_spilled( Node *src, Node *dst ); 611 // Set the 'spilled_once' or 'spilled_twice' flag on a node. 612 void set_was_spilled( Node *n ); 613 614 // Convert ideal spill-nodes into machine loads & stores 615 // Set C->failing when fixup spills could not complete, node limit exceeded. 616 void fixup_spills(); 617 618 // Post-Allocation peephole copy removal 619 void post_allocate_copy_removal(); 620 Node *skip_copies( Node *c ); 621 // Replace the old node with the current live version of that value 622 // and yank the old value if it's dead. 623 int replace_and_yank_if_dead( Node *old, OptoReg::Name nreg, 624 Block *current_block, Node_List& value, Node_List& regnd ) { 625 Node* v = regnd[nreg]; 626 assert(v->outcnt() != 0, "no dead values"); 627 old->replace_by(v); 628 return yank_if_dead(old, current_block, &value, ®nd); 629 } 630 631 int yank_if_dead( Node *old, Block *current_block, Node_List *value, Node_List *regnd ) { 632 return yank_if_dead_recurse(old, old, current_block, value, regnd); 633 } 634 int yank_if_dead_recurse(Node *old, Node *orig_old, Block *current_block, 635 Node_List *value, Node_List *regnd); 636 int yank( Node *old, Block *current_block, Node_List *value, Node_List *regnd ); 637 int elide_copy( Node *n, int k, Block *current_block, Node_List &value, Node_List ®nd, bool can_change_regs ); 638 int use_prior_register( Node *copy, uint idx, Node *def, Block *current_block, Node_List &value, Node_List ®nd ); 639 bool may_be_copy_of_callee( Node *def ) const; 640 641 // If nreg already contains the same constant as val then eliminate it 642 bool eliminate_copy_of_constant(Node* val, Node* n, 643 Block *current_block, Node_List& value, Node_List ®nd, 644 OptoReg::Name nreg, OptoReg::Name nreg2); 645 // Extend the node to LRG mapping 646 void add_reference( const Node *node, const Node *old_node); 647 648 private: 649 650 static int _final_loads, _final_stores, _final_copies, _final_memoves; 651 static double _final_load_cost, _final_store_cost, _final_copy_cost, _final_memove_cost; 652 static int _conserv_coalesce, _conserv_coalesce_pair; 653 static int _conserv_coalesce_trie, _conserv_coalesce_quad; 654 static int _post_alloc; 655 static int _lost_opp_pp_coalesce, _lost_opp_cflow_coalesce; 656 static int _used_cisc_instructions, _unused_cisc_instructions; 657 static int _allocator_attempts, _allocator_successes; 658 659 #ifndef PRODUCT 660 static uint _high_pressure, _low_pressure; 661 662 void dump() const; 663 void dump( const Node *n ) const; 664 void dump( const Block * b ) const; 665 void dump_degree_lists() const; 666 void dump_simplified() const; 667 void dump_lrg( uint lidx, bool defs_only) const; 668 void dump_lrg( uint lidx) const { 669 // dump defs and uses by default 670 dump_lrg(lidx, false); 671 } 672 void dump_bb( uint pre_order ) const; 673 674 // Verify that base pointers and derived pointers are still sane 675 void verify_base_ptrs( ResourceArea *a ) const; 676 677 void verify( ResourceArea *a, bool verify_ifg = false ) const; 678 679 void dump_for_spill_split_recycle() const; 680 681 public: 682 void dump_frame() const; 683 char *dump_register( const Node *n, char *buf ) const; 684 private: 685 static void print_chaitin_statistics(); 686 #endif 687 friend class PhaseCoalesce; 688 friend class PhaseAggressiveCoalesce; 689 friend class PhaseConservativeCoalesce; 690 }; 691 692 #endif // SHARE_VM_OPTO_CHAITIN_HPP