1 /* 2 * Copyright (c) 2007, 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 #ifndef SHARE_VM_OPTO_SUPERWORD_HPP 25 #define SHARE_VM_OPTO_SUPERWORD_HPP 26 27 #include "opto/loopnode.hpp" 28 #include "opto/node.hpp" 29 #include "opto/phaseX.hpp" 30 #include "opto/vectornode.hpp" 31 #include "utilities/growableArray.hpp" 32 33 // 34 // S U P E R W O R D T R A N S F O R M 35 // 36 // SuperWords are short, fixed length vectors. 37 // 38 // Algorithm from: 39 // 40 // Exploiting SuperWord Level Parallelism with 41 // Multimedia Instruction Sets 42 // by 43 // Samuel Larsen and Saman Amarasighe 44 // MIT Laboratory for Computer Science 45 // date 46 // May 2000 47 // published in 48 // ACM SIGPLAN Notices 49 // Proceedings of ACM PLDI '00, Volume 35 Issue 5 50 // 51 // Definition 3.1 A Pack is an n-tuple, <s1, ...,sn>, where 52 // s1,...,sn are independent isomorphic statements in a basic 53 // block. 54 // 55 // Definition 3.2 A PackSet is a set of Packs. 56 // 57 // Definition 3.3 A Pair is a Pack of size two, where the 58 // first statement is considered the left element, and the 59 // second statement is considered the right element. 60 61 class SWPointer; 62 class OrderedPair; 63 64 // ========================= Dependence Graph ===================== 65 66 class DepMem; 67 68 //------------------------------DepEdge--------------------------- 69 // An edge in the dependence graph. The edges incident to a dependence 70 // node are threaded through _next_in for incoming edges and _next_out 71 // for outgoing edges. 72 class DepEdge : public ResourceObj { 73 protected: 74 DepMem* _pred; 75 DepMem* _succ; 76 DepEdge* _next_in; // list of in edges, null terminated 77 DepEdge* _next_out; // list of out edges, null terminated 78 79 public: 80 DepEdge(DepMem* pred, DepMem* succ, DepEdge* next_in, DepEdge* next_out) : 81 _pred(pred), _succ(succ), _next_in(next_in), _next_out(next_out) {} 82 83 DepEdge* next_in() { return _next_in; } 84 DepEdge* next_out() { return _next_out; } 85 DepMem* pred() { return _pred; } 86 DepMem* succ() { return _succ; } 87 88 void print(); 89 }; 90 91 //------------------------------DepMem--------------------------- 92 // A node in the dependence graph. _in_head starts the threaded list of 93 // incoming edges, and _out_head starts the list of outgoing edges. 94 class DepMem : public ResourceObj { 95 protected: 96 Node* _node; // Corresponding ideal node 97 DepEdge* _in_head; // Head of list of in edges, null terminated 98 DepEdge* _out_head; // Head of list of out edges, null terminated 99 100 public: 101 DepMem(Node* node) : _node(node), _in_head(NULL), _out_head(NULL) {} 102 103 Node* node() { return _node; } 104 DepEdge* in_head() { return _in_head; } 105 DepEdge* out_head() { return _out_head; } 106 void set_in_head(DepEdge* hd) { _in_head = hd; } 107 void set_out_head(DepEdge* hd) { _out_head = hd; } 108 109 int in_cnt(); // Incoming edge count 110 int out_cnt(); // Outgoing edge count 111 112 void print(); 113 }; 114 115 //------------------------------DepGraph--------------------------- 116 class DepGraph VALUE_OBJ_CLASS_SPEC { 117 protected: 118 Arena* _arena; 119 GrowableArray<DepMem*> _map; 120 DepMem* _root; 121 DepMem* _tail; 122 123 public: 124 DepGraph(Arena* a) : _arena(a), _map(a, 8, 0, NULL) { 125 _root = new (_arena) DepMem(NULL); 126 _tail = new (_arena) DepMem(NULL); 127 } 128 129 DepMem* root() { return _root; } 130 DepMem* tail() { return _tail; } 131 132 // Return dependence node corresponding to an ideal node 133 DepMem* dep(Node* node) { return _map.at(node->_idx); } 134 135 // Make a new dependence graph node for an ideal node. 136 DepMem* make_node(Node* node); 137 138 // Make a new dependence graph edge dprec->dsucc 139 DepEdge* make_edge(DepMem* dpred, DepMem* dsucc); 140 141 DepEdge* make_edge(Node* pred, Node* succ) { return make_edge(dep(pred), dep(succ)); } 142 DepEdge* make_edge(DepMem* pred, Node* succ) { return make_edge(pred, dep(succ)); } 143 DepEdge* make_edge(Node* pred, DepMem* succ) { return make_edge(dep(pred), succ); } 144 145 void init() { _map.clear(); } // initialize 146 147 void print(Node* n) { dep(n)->print(); } 148 void print(DepMem* d) { d->print(); } 149 }; 150 151 //------------------------------DepPreds--------------------------- 152 // Iterator over predecessors in the dependence graph and 153 // non-memory-graph inputs of ideal nodes. 154 class DepPreds : public StackObj { 155 private: 156 Node* _n; 157 int _next_idx, _end_idx; 158 DepEdge* _dep_next; 159 Node* _current; 160 bool _done; 161 162 public: 163 DepPreds(Node* n, DepGraph& dg); 164 Node* current() { return _current; } 165 bool done() { return _done; } 166 void next(); 167 }; 168 169 //------------------------------DepSuccs--------------------------- 170 // Iterator over successors in the dependence graph and 171 // non-memory-graph outputs of ideal nodes. 172 class DepSuccs : public StackObj { 173 private: 174 Node* _n; 175 int _next_idx, _end_idx; 176 DepEdge* _dep_next; 177 Node* _current; 178 bool _done; 179 180 public: 181 DepSuccs(Node* n, DepGraph& dg); 182 Node* current() { return _current; } 183 bool done() { return _done; } 184 void next(); 185 }; 186 187 188 // ========================= SuperWord ===================== 189 190 // -----------------------------SWNodeInfo--------------------------------- 191 // Per node info needed by SuperWord 192 class SWNodeInfo VALUE_OBJ_CLASS_SPEC { 193 public: 194 int _alignment; // memory alignment for a node 195 int _depth; // Max expression (DAG) depth from block start 196 const Type* _velt_type; // vector element type 197 Node_List* _my_pack; // pack containing this node 198 199 SWNodeInfo() : _alignment(-1), _depth(0), _velt_type(NULL), _my_pack(NULL) {} 200 static const SWNodeInfo initial; 201 }; 202 203 // -----------------------------SuperWord--------------------------------- 204 // Transforms scalar operations into packed (superword) operations. 205 class SuperWord : public ResourceObj { 206 private: 207 PhaseIdealLoop* _phase; 208 Arena* _arena; 209 PhaseIterGVN &_igvn; 210 211 enum consts { top_align = -1, bottom_align = -666 }; 212 213 GrowableArray<Node_List*> _packset; // Packs for the current block 214 215 GrowableArray<int> _bb_idx; // Map from Node _idx to index within block 216 217 GrowableArray<Node*> _block; // Nodes in current block 218 GrowableArray<Node*> _data_entry; // Nodes with all inputs from outside 219 GrowableArray<Node*> _mem_slice_head; // Memory slice head nodes 220 GrowableArray<Node*> _mem_slice_tail; // Memory slice tail nodes 221 222 GrowableArray<SWNodeInfo> _node_info; // Info needed per node 223 224 MemNode* _align_to_ref; // Memory reference that pre-loop will align to 225 226 GrowableArray<OrderedPair> _disjoint_ptrs; // runtime disambiguated pointer pairs 227 228 DepGraph _dg; // Dependence graph 229 230 // Scratch pads 231 VectorSet _visited; // Visited set 232 VectorSet _post_visited; // Post-visited set 233 Node_Stack _n_idx_list; // List of (node,index) pairs 234 GrowableArray<Node*> _nlist; // List of nodes 235 GrowableArray<Node*> _stk; // Stack of nodes 236 237 public: 238 SuperWord(PhaseIdealLoop* phase); 239 240 void transform_loop(IdealLoopTree* lpt, bool do_optimization); 241 242 // Accessors for SWPointer 243 PhaseIdealLoop* phase() { return _phase; } 244 IdealLoopTree* lpt() { return _lpt; } 245 PhiNode* iv() { return _iv; } 246 bool early_return() { return _early_return; } 247 248 private: 249 IdealLoopTree* _lpt; // Current loop tree node 250 LoopNode* _lp; // Current LoopNode 251 Node* _bb; // Current basic block 252 PhiNode* _iv; // Induction var 253 bool _race_possible; // In cases where SDMU is true 254 bool _early_return; // True if we do not initialize 255 256 // Accessors 257 Arena* arena() { return _arena; } 258 259 Node* bb() { return _bb; } 260 void set_bb(Node* bb) { _bb = bb; } 261 262 void set_lpt(IdealLoopTree* lpt) { _lpt = lpt; } 263 264 LoopNode* lp() { return _lp; } 265 void set_lp(LoopNode* lp) { _lp = lp; 266 _iv = lp->as_CountedLoop()->phi()->as_Phi(); } 267 int iv_stride() { return lp()->as_CountedLoop()->stride_con(); } 268 269 int vector_width(Node* n) { 270 BasicType bt = velt_basic_type(n); 271 return MIN2(ABS(iv_stride()), Matcher::max_vector_size(bt)); 272 } 273 int vector_width_in_bytes(Node* n) { 274 BasicType bt = velt_basic_type(n); 275 return vector_width(n)*type2aelembytes(bt); 276 } 277 MemNode* align_to_ref() { return _align_to_ref; } 278 void set_align_to_ref(MemNode* m) { _align_to_ref = m; } 279 280 Node* ctrl(Node* n) const { return _phase->has_ctrl(n) ? _phase->get_ctrl(n) : n; } 281 282 // block accessors 283 bool in_bb(Node* n) { return n != NULL && n->outcnt() > 0 && ctrl(n) == _bb; } 284 int bb_idx(Node* n) { assert(in_bb(n), "must be"); return _bb_idx.at(n->_idx); } 285 void set_bb_idx(Node* n, int i) { _bb_idx.at_put_grow(n->_idx, i); } 286 287 // visited set accessors 288 void visited_clear() { _visited.Clear(); } 289 void visited_set(Node* n) { return _visited.set(bb_idx(n)); } 290 int visited_test(Node* n) { return _visited.test(bb_idx(n)); } 291 int visited_test_set(Node* n) { return _visited.test_set(bb_idx(n)); } 292 void post_visited_clear() { _post_visited.Clear(); } 293 void post_visited_set(Node* n) { return _post_visited.set(bb_idx(n)); } 294 int post_visited_test(Node* n) { return _post_visited.test(bb_idx(n)); } 295 296 // Ensure node_info contains element "i" 297 void grow_node_info(int i) { if (i >= _node_info.length()) _node_info.at_put_grow(i, SWNodeInfo::initial); } 298 299 // memory alignment for a node 300 int alignment(Node* n) { return _node_info.adr_at(bb_idx(n))->_alignment; } 301 void set_alignment(Node* n, int a) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_alignment = a; } 302 303 // Max expression (DAG) depth from beginning of the block for each node 304 int depth(Node* n) { return _node_info.adr_at(bb_idx(n))->_depth; } 305 void set_depth(Node* n, int d) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_depth = d; } 306 307 // vector element type 308 const Type* velt_type(Node* n) { return _node_info.adr_at(bb_idx(n))->_velt_type; } 309 BasicType velt_basic_type(Node* n) { return velt_type(n)->array_element_basic_type(); } 310 void set_velt_type(Node* n, const Type* t) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_velt_type = t; } 311 bool same_velt_type(Node* n1, Node* n2); 312 313 // my_pack 314 Node_List* my_pack(Node* n) { return !in_bb(n) ? NULL : _node_info.adr_at(bb_idx(n))->_my_pack; } 315 void set_my_pack(Node* n, Node_List* p) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_my_pack = p; } 316 317 // methods 318 319 // Extract the superword level parallelism 320 void SLP_extract(); 321 // Find the adjacent memory references and create pack pairs for them. 322 void find_adjacent_refs(); 323 // Find a memory reference to align the loop induction variable to. 324 MemNode* find_align_to_ref(Node_List &memops); 325 // Calculate loop's iv adjustment for this memory ops. 326 int get_iv_adjustment(MemNode* mem); 327 // Can the preloop align the reference to position zero in the vector? 328 bool ref_is_alignable(SWPointer& p); 329 // Construct dependency graph. 330 void dependence_graph(); 331 // Return a memory slice (node list) in predecessor order starting at "start" 332 void mem_slice_preds(Node* start, Node* stop, GrowableArray<Node*> &preds); 333 // Can s1 and s2 be in a pack with s1 immediately preceding s2 and s1 aligned at "align" 334 bool stmts_can_pack(Node* s1, Node* s2, int align); 335 // Does s exist in a pack at position pos? 336 bool exists_at(Node* s, uint pos); 337 // Is s1 immediately before s2 in memory? 338 bool are_adjacent_refs(Node* s1, Node* s2); 339 // Are s1 and s2 similar? 340 bool isomorphic(Node* s1, Node* s2); 341 // Is there no data path from s1 to s2 or s2 to s1? 342 bool independent(Node* s1, Node* s2); 343 // Is there a data path between s1 and s2 and both are reductions? 344 bool reduction(Node* s1, Node* s2); 345 // Helper for independent 346 bool independent_path(Node* shallow, Node* deep, uint dp=0); 347 void set_alignment(Node* s1, Node* s2, int align); 348 int data_size(Node* s); 349 // Extend packset by following use->def and def->use links from pack members. 350 void extend_packlist(); 351 // Extend the packset by visiting operand definitions of nodes in pack p 352 bool follow_use_defs(Node_List* p); 353 // Extend the packset by visiting uses of nodes in pack p 354 bool follow_def_uses(Node_List* p); 355 // For extended packsets, ordinally arrange uses packset by major component 356 void order_def_uses(Node_List* p); 357 // Estimate the savings from executing s1 and s2 as a pack 358 int est_savings(Node* s1, Node* s2); 359 int adjacent_profit(Node* s1, Node* s2); 360 int pack_cost(int ct); 361 int unpack_cost(int ct); 362 // Combine packs A and B with A.last == B.first into A.first..,A.last,B.second,..B.last 363 void combine_packs(); 364 // Construct the map from nodes to packs. 365 void construct_my_pack_map(); 366 // Remove packs that are not implemented or not profitable. 367 void filter_packs(); 368 // Adjust the memory graph for the packed operations 369 void schedule(); 370 // Remove "current" from its current position in the memory graph and insert 371 // it after the appropriate insert points (lip or uip); 372 void remove_and_insert(MemNode *current, MemNode *prev, MemNode *lip, Node *uip, Unique_Node_List &schd_before); 373 // Within a store pack, schedule stores together by moving out the sandwiched memory ops according 374 // to dependence info; and within a load pack, move loads down to the last executed load. 375 void co_locate_pack(Node_List* p); 376 // Convert packs into vector node operations 377 void output(); 378 // Create a vector operand for the nodes in pack p for operand: in(opd_idx) 379 Node* vector_opd(Node_List* p, int opd_idx); 380 // Can code be generated for pack p? 381 bool implemented(Node_List* p); 382 // For pack p, are all operands and all uses (with in the block) vector? 383 bool profitable(Node_List* p); 384 // If a use of pack p is not a vector use, then replace the use with an extract operation. 385 void insert_extracts(Node_List* p); 386 // Is use->in(u_idx) a vector use? 387 bool is_vector_use(Node* use, int u_idx); 388 // Construct reverse postorder list of block members 389 bool construct_bb(); 390 // Initialize per node info 391 void initialize_bb(); 392 // Insert n into block after pos 393 void bb_insert_after(Node* n, int pos); 394 // Compute max depth for expressions from beginning of block 395 void compute_max_depth(); 396 // Compute necessary vector element type for expressions 397 void compute_vector_element_type(); 398 // Are s1 and s2 in a pack pair and ordered as s1,s2? 399 bool in_packset(Node* s1, Node* s2); 400 // Is s in pack p? 401 Node_List* in_pack(Node* s, Node_List* p); 402 // Remove the pack at position pos in the packset 403 void remove_pack_at(int pos); 404 // Return the node executed first in pack p. 405 Node* executed_first(Node_List* p); 406 // Return the node executed last in pack p. 407 Node* executed_last(Node_List* p); 408 // Alignment within a vector memory reference 409 int memory_alignment(MemNode* s, int iv_adjust); 410 // (Start, end] half-open range defining which operands are vector 411 void vector_opd_range(Node* n, uint* start, uint* end); 412 // Smallest type containing range of values 413 const Type* container_type(Node* n); 414 // Adjust pre-loop limit so that in main loop, a load/store reference 415 // to align_to_ref will be a position zero in the vector. 416 void align_initial_loop_index(MemNode* align_to_ref); 417 // Find pre loop end from main loop. Returns null if none. 418 CountedLoopEndNode* get_pre_loop_end(CountedLoopNode *cl); 419 // Is the use of d1 in u1 at the same operand position as d2 in u2? 420 bool opnd_positions_match(Node* d1, Node* u1, Node* d2, Node* u2); 421 void init(); 422 423 // print methods 424 void print_packset(); 425 void print_pack(Node_List* p); 426 void print_bb(); 427 void print_stmt(Node* s); 428 char* blank(uint depth); 429 430 void packset_sort(int n); 431 }; 432 433 434 435 //------------------------------SWPointer--------------------------- 436 // Information about an address for dependence checking and vector alignment 437 class SWPointer VALUE_OBJ_CLASS_SPEC { 438 protected: 439 MemNode* _mem; // My memory reference node 440 SuperWord* _slp; // SuperWord class 441 442 Node* _base; // NULL if unsafe nonheap reference 443 Node* _adr; // address pointer 444 jint _scale; // multipler for iv (in bytes), 0 if no loop iv 445 jint _offset; // constant offset (in bytes) 446 Node* _invar; // invariant offset (in bytes), NULL if none 447 bool _negate_invar; // if true then use: (0 - _invar) 448 Node_Stack* _nstack; // stack used to record a swpointer trace of variants 449 bool _analyze_only; // Used in loop unrolling only for swpointer trace 450 uint _stack_idx; // Used in loop unrolling only for swpointer trace 451 452 PhaseIdealLoop* phase() { return _slp->phase(); } 453 IdealLoopTree* lpt() { return _slp->lpt(); } 454 PhiNode* iv() { return _slp->iv(); } // Induction var 455 456 bool invariant(Node* n) { 457 Node *n_c = phase()->get_ctrl(n); 458 return !lpt()->is_member(phase()->get_loop(n_c)); 459 } 460 461 // Match: k*iv + offset 462 bool scaled_iv_plus_offset(Node* n); 463 // Match: k*iv where k is a constant that's not zero 464 bool scaled_iv(Node* n); 465 // Match: offset is (k [+/- invariant]) 466 bool offset_plus_k(Node* n, bool negate = false); 467 468 public: 469 enum CMP { 470 Less = 1, 471 Greater = 2, 472 Equal = 4, 473 NotEqual = (Less | Greater), 474 NotComparable = (Less | Greater | Equal) 475 }; 476 477 SWPointer(MemNode* mem, SuperWord* slp, Node_Stack *nstack, bool analyze_only); 478 // Following is used to create a temporary object during 479 // the pattern match of an address expression. 480 SWPointer(SWPointer* p); 481 482 bool valid() { return _adr != NULL; } 483 bool has_iv() { return _scale != 0; } 484 485 Node* base() { return _base; } 486 Node* adr() { return _adr; } 487 MemNode* mem() { return _mem; } 488 int scale_in_bytes() { return _scale; } 489 Node* invar() { return _invar; } 490 bool negate_invar() { return _negate_invar; } 491 int offset_in_bytes() { return _offset; } 492 int memory_size() { return _mem->memory_size(); } 493 Node_Stack* node_stack() { return _nstack; } 494 495 // Comparable? 496 int cmp(SWPointer& q) { 497 if (valid() && q.valid() && 498 (_adr == q._adr || _base == _adr && q._base == q._adr) && 499 _scale == q._scale && 500 _invar == q._invar && 501 _negate_invar == q._negate_invar) { 502 bool overlap = q._offset < _offset + memory_size() && 503 _offset < q._offset + q.memory_size(); 504 return overlap ? Equal : (_offset < q._offset ? Less : Greater); 505 } else { 506 return NotComparable; 507 } 508 } 509 510 bool not_equal(SWPointer& q) { return not_equal(cmp(q)); } 511 bool equal(SWPointer& q) { return equal(cmp(q)); } 512 bool comparable(SWPointer& q) { return comparable(cmp(q)); } 513 static bool not_equal(int cmp) { return cmp <= NotEqual; } 514 static bool equal(int cmp) { return cmp == Equal; } 515 static bool comparable(int cmp) { return cmp < NotComparable; } 516 517 void print(); 518 }; 519 520 521 //------------------------------OrderedPair--------------------------- 522 // Ordered pair of Node*. 523 class OrderedPair VALUE_OBJ_CLASS_SPEC { 524 protected: 525 Node* _p1; 526 Node* _p2; 527 public: 528 OrderedPair() : _p1(NULL), _p2(NULL) {} 529 OrderedPair(Node* p1, Node* p2) { 530 if (p1->_idx < p2->_idx) { 531 _p1 = p1; _p2 = p2; 532 } else { 533 _p1 = p2; _p2 = p1; 534 } 535 } 536 537 bool operator==(const OrderedPair &rhs) { 538 return _p1 == rhs._p1 && _p2 == rhs._p2; 539 } 540 void print() { tty->print(" (%d, %d)", _p1->_idx, _p2->_idx); } 541 542 static const OrderedPair initial; 543 }; 544 545 #endif // SHARE_VM_OPTO_SUPERWORD_HPP