1 /*
   2  * Copyright (c) 2007, 2018, 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 #include "precompiled.hpp"
  25 #include "compiler/compileLog.hpp"
  26 #include "libadt/vectset.hpp"
  27 #include "memory/allocation.inline.hpp"
  28 #include "memory/resourceArea.hpp"
  29 #include "opto/addnode.hpp"
  30 #include "opto/callnode.hpp"
  31 #include "opto/castnode.hpp"
  32 #include "opto/convertnode.hpp"
  33 #include "opto/divnode.hpp"
  34 #include "opto/matcher.hpp"
  35 #include "opto/memnode.hpp"
  36 #include "opto/mulnode.hpp"
  37 #include "opto/opcodes.hpp"
  38 #include "opto/opaquenode.hpp"
  39 #include "opto/superword.hpp"
  40 #include "opto/vectornode.hpp"
  41 #include "opto/movenode.hpp"
  42 
  43 //
  44 //                  S U P E R W O R D   T R A N S F O R M
  45 //=============================================================================
  46 
  47 //------------------------------SuperWord---------------------------
  48 SuperWord::SuperWord(PhaseIdealLoop* phase) :
  49   _phase(phase),
  50   _igvn(phase->_igvn),
  51   _arena(phase->C->comp_arena()),
  52   _packset(arena(), 8,  0, NULL),         // packs for the current block
  53   _bb_idx(arena(), (int)(1.10 * phase->C->unique()), 0, 0), // node idx to index in bb
  54   _block(arena(), 8,  0, NULL),           // nodes in current block
  55   _post_block(arena(), 8, 0, NULL),       // nodes common to current block which are marked as post loop vectorizable
  56   _data_entry(arena(), 8,  0, NULL),      // nodes with all inputs from outside
  57   _mem_slice_head(arena(), 8,  0, NULL),  // memory slice heads
  58   _mem_slice_tail(arena(), 8,  0, NULL),  // memory slice tails
  59   _node_info(arena(), 8,  0, SWNodeInfo::initial), // info needed per node
  60   _clone_map(phase->C->clone_map()),      // map of nodes created in cloning
  61   _cmovev_kit(_arena, this),              // map to facilitate CMoveV creation
  62   _align_to_ref(NULL),                    // memory reference to align vectors to
  63   _disjoint_ptrs(arena(), 8,  0, OrderedPair::initial), // runtime disambiguated pointer pairs
  64   _dg(_arena),                            // dependence graph
  65   _visited(arena()),                      // visited node set
  66   _post_visited(arena()),                 // post visited node set
  67   _n_idx_list(arena(), 8),                // scratch list of (node,index) pairs
  68   _stk(arena(), 8, 0, NULL),              // scratch stack of nodes
  69   _nlist(arena(), 8, 0, NULL),            // scratch list of nodes
  70   _lpt(NULL),                             // loop tree node
  71   _lp(NULL),                              // LoopNode
  72   _bb(NULL),                              // basic block
  73   _iv(NULL),                              // induction var
  74   _race_possible(false),                  // cases where SDMU is true
  75   _early_return(true),                    // analysis evaluations routine
  76   _num_work_vecs(0),                      // amount of vector work we have
  77   _num_reductions(0),                     // amount of reduction work we have
  78   _do_vector_loop(phase->C->do_vector_loop()),  // whether to do vectorization/simd style
  79   _do_reserve_copy(DoReserveCopyInSuperWord),
  80   _ii_first(-1),                          // first loop generation index - only if do_vector_loop()
  81   _ii_last(-1),                           // last loop generation index - only if do_vector_loop()
  82   _ii_order(arena(), 8, 0, 0)
  83 {
  84 #ifndef PRODUCT
  85   _vector_loop_debug = 0;
  86   if (_phase->C->method() != NULL) {
  87     _vector_loop_debug = phase->C->directive()->VectorizeDebugOption;
  88   }
  89 
  90 #endif
  91 }
  92 
  93 //------------------------------transform_loop---------------------------
  94 void SuperWord::transform_loop(IdealLoopTree* lpt, bool do_optimization) {
  95   assert(UseSuperWord, "should be");
  96   // Do vectors exist on this architecture?
  97   if (Matcher::vector_width_in_bytes(T_BYTE) < 2) return;
  98 
  99   assert(lpt->_head->is_CountedLoop(), "must be");
 100   CountedLoopNode *cl = lpt->_head->as_CountedLoop();
 101 
 102   if (!cl->is_valid_counted_loop()) return; // skip malformed counted loop
 103 
 104   bool post_loop_allowed = (PostLoopMultiversioning && Matcher::has_predicated_vectors() && cl->is_post_loop());
 105   if (post_loop_allowed) {
 106     if (cl->is_reduction_loop()) return; // no predication mapping
 107     Node *limit = cl->limit();
 108     if (limit->is_Con()) return; // non constant limits only
 109     // Now check the limit for expressions we do not handle
 110     if (limit->is_Add()) {
 111       Node *in2 = limit->in(2);
 112       if (in2->is_Con()) {
 113         int val = in2->get_int();
 114         // should not try to program these cases
 115         if (val < 0) return;
 116       }
 117     }
 118   }
 119 
 120   // skip any loop that has not been assigned max unroll by analysis
 121   if (do_optimization) {
 122     if (SuperWordLoopUnrollAnalysis && cl->slp_max_unroll() == 0) return;
 123   }
 124 
 125   // Check for no control flow in body (other than exit)
 126   Node *cl_exit = cl->loopexit();
 127   if (cl->is_main_loop() && (cl_exit->in(0) != lpt->_head)) {
 128     #ifndef PRODUCT
 129       if (TraceSuperWord) {
 130         tty->print_cr("SuperWord::transform_loop: loop too complicated, cl_exit->in(0) != lpt->_head");
 131         tty->print("cl_exit %d", cl_exit->_idx); cl_exit->dump();
 132         tty->print("cl_exit->in(0) %d", cl_exit->in(0)->_idx); cl_exit->in(0)->dump();
 133         tty->print("lpt->_head %d", lpt->_head->_idx); lpt->_head->dump();
 134         lpt->dump_head();
 135       }
 136     #endif
 137     return;
 138   }
 139 
 140   // Make sure the are no extra control users of the loop backedge
 141   if (cl->back_control()->outcnt() != 1) {
 142     return;
 143   }
 144 
 145   // Skip any loops already optimized by slp
 146   if (cl->is_vectorized_loop()) return;
 147 
 148   if (cl->do_unroll_only()) return;
 149 
 150   if (cl->is_main_loop()) {
 151     // Check for pre-loop ending with CountedLoopEnd(Bool(Cmp(x,Opaque1(limit))))
 152     CountedLoopEndNode* pre_end = get_pre_loop_end(cl);
 153     if (pre_end == NULL) return;
 154     Node *pre_opaq1 = pre_end->limit();
 155     if (pre_opaq1->Opcode() != Op_Opaque1) return;
 156   }
 157 
 158   init(); // initialize data structures
 159 
 160   set_lpt(lpt);
 161   set_lp(cl);
 162 
 163   // For now, define one block which is the entire loop body
 164   set_bb(cl);
 165 
 166   if (do_optimization) {
 167     assert(_packset.length() == 0, "packset must be empty");
 168     SLP_extract();
 169     if (PostLoopMultiversioning && Matcher::has_predicated_vectors()) {
 170       if (cl->is_vectorized_loop() && cl->is_main_loop() && !cl->is_reduction_loop()) {
 171         IdealLoopTree *lpt_next = lpt->_next;
 172         CountedLoopNode *cl_next = lpt_next->_head->as_CountedLoop();
 173         _phase->has_range_checks(lpt_next);
 174         if (cl_next->is_post_loop() && !cl_next->range_checks_present()) {
 175           if (!cl_next->is_vectorized_loop()) {
 176             int slp_max_unroll_factor = cl->slp_max_unroll();
 177             cl_next->set_slp_max_unroll(slp_max_unroll_factor);
 178           }
 179         }
 180       }
 181     }
 182   }
 183 }
 184 
 185 //------------------------------early unrolling analysis------------------------------
 186 void SuperWord::unrolling_analysis(int &local_loop_unroll_factor) {
 187   bool is_slp = true;
 188   ResourceMark rm;
 189   size_t ignored_size = lpt()->_body.size();
 190   int *ignored_loop_nodes = NEW_RESOURCE_ARRAY(int, ignored_size);
 191   Node_Stack nstack((int)ignored_size);
 192   CountedLoopNode *cl = lpt()->_head->as_CountedLoop();
 193   Node *cl_exit = cl->loopexit_or_null();
 194   int rpo_idx = _post_block.length();
 195 
 196   assert(rpo_idx == 0, "post loop block is empty");
 197 
 198   // First clear the entries
 199   for (uint i = 0; i < lpt()->_body.size(); i++) {
 200     ignored_loop_nodes[i] = -1;
 201   }
 202 
 203   int max_vector = Matcher::max_vector_size(T_BYTE);
 204   bool post_loop_allowed = (PostLoopMultiversioning && Matcher::has_predicated_vectors() && cl->is_post_loop());
 205 
 206   // Process the loop, some/all of the stack entries will not be in order, ergo
 207   // need to preprocess the ignored initial state before we process the loop
 208   for (uint i = 0; i < lpt()->_body.size(); i++) {
 209     Node* n = lpt()->_body.at(i);
 210     if (n == cl->incr() ||
 211       n->is_reduction() ||
 212       n->is_AddP() ||
 213       n->is_Cmp() ||
 214       n->is_IfTrue() ||
 215       n->is_CountedLoop() ||
 216       (n == cl_exit)) {
 217       ignored_loop_nodes[i] = n->_idx;
 218       continue;
 219     }
 220 
 221     if (n->is_If()) {
 222       IfNode *iff = n->as_If();
 223       if (iff->_fcnt != COUNT_UNKNOWN && iff->_prob != PROB_UNKNOWN) {
 224         if (lpt()->is_loop_exit(iff)) {
 225           ignored_loop_nodes[i] = n->_idx;
 226           continue;
 227         }
 228       }
 229     }
 230 
 231     if (n->is_Phi() && (n->bottom_type() == Type::MEMORY)) {
 232       Node* n_tail = n->in(LoopNode::LoopBackControl);
 233       if (n_tail != n->in(LoopNode::EntryControl)) {
 234         if (!n_tail->is_Mem()) {
 235           is_slp = false;
 236           break;
 237         }
 238       }
 239     }
 240 
 241     // This must happen after check of phi/if
 242     if (n->is_Phi() || n->is_If()) {
 243       ignored_loop_nodes[i] = n->_idx;
 244       continue;
 245     }
 246 
 247     if (n->is_LoadStore() || n->is_MergeMem() ||
 248       (n->is_Proj() && !n->as_Proj()->is_CFG())) {
 249       is_slp = false;
 250       break;
 251     }
 252 
 253     // Ignore nodes with non-primitive type.
 254     BasicType bt;
 255     if (n->is_Mem()) {
 256       bt = n->as_Mem()->memory_type();
 257     } else {
 258       bt = n->bottom_type()->basic_type();
 259     }
 260     if (is_java_primitive(bt) == false) {
 261       ignored_loop_nodes[i] = n->_idx;
 262       continue;
 263     }
 264 
 265     if (n->is_Mem()) {
 266       MemNode* current = n->as_Mem();
 267       Node* adr = n->in(MemNode::Address);
 268       Node* n_ctrl = _phase->get_ctrl(adr);
 269 
 270       // save a queue of post process nodes
 271       if (n_ctrl != NULL && lpt()->is_member(_phase->get_loop(n_ctrl))) {
 272         // Process the memory expression
 273         int stack_idx = 0;
 274         bool have_side_effects = true;
 275         if (adr->is_AddP() == false) {
 276           nstack.push(adr, stack_idx++);
 277         } else {
 278           // Mark the components of the memory operation in nstack
 279           SWPointer p1(current, this, &nstack, true);
 280           have_side_effects = p1.node_stack()->is_nonempty();
 281         }
 282 
 283         // Process the pointer stack
 284         while (have_side_effects) {
 285           Node* pointer_node = nstack.node();
 286           for (uint j = 0; j < lpt()->_body.size(); j++) {
 287             Node* cur_node = lpt()->_body.at(j);
 288             if (cur_node == pointer_node) {
 289               ignored_loop_nodes[j] = cur_node->_idx;
 290               break;
 291             }
 292           }
 293           nstack.pop();
 294           have_side_effects = nstack.is_nonempty();
 295         }
 296       }
 297     }
 298   }
 299 
 300   if (is_slp) {
 301     // Now we try to find the maximum supported consistent vector which the machine
 302     // description can use
 303     bool small_basic_type = false;
 304     bool flag_small_bt = false;
 305     for (uint i = 0; i < lpt()->_body.size(); i++) {
 306       if (ignored_loop_nodes[i] != -1) continue;
 307 
 308       BasicType bt;
 309       Node* n = lpt()->_body.at(i);
 310       if (n->is_Mem()) {
 311         bt = n->as_Mem()->memory_type();
 312       } else {
 313         bt = n->bottom_type()->basic_type();
 314       }
 315 
 316       if (post_loop_allowed) {
 317         if (!small_basic_type) {
 318           switch (bt) {
 319           case T_CHAR:
 320           case T_BYTE:
 321           case T_SHORT:
 322             small_basic_type = true;
 323             break;
 324 
 325           case T_LONG:
 326             // TODO: Remove when support completed for mask context with LONG.
 327             //       Support needs to be augmented for logical qword operations, currently we map to dword
 328             //       buckets for vectors on logicals as these were legacy.
 329             small_basic_type = true;
 330             break;
 331 
 332           default:
 333             break;
 334           }
 335         }
 336       }
 337 
 338       if (is_java_primitive(bt) == false) continue;
 339 
 340          int cur_max_vector = Matcher::max_vector_size(bt);
 341 
 342       // If a max vector exists which is not larger than _local_loop_unroll_factor
 343       // stop looking, we already have the max vector to map to.
 344       if (cur_max_vector < local_loop_unroll_factor) {
 345         is_slp = false;
 346         if (TraceSuperWordLoopUnrollAnalysis) {
 347           tty->print_cr("slp analysis fails: unroll limit greater than max vector\n");
 348         }
 349         break;
 350       }
 351 
 352       // Map the maximal common vector
 353       if (VectorNode::implemented(n->Opcode(), cur_max_vector, bt)) {
 354         if (cur_max_vector < max_vector && !flag_small_bt) {
 355           max_vector = cur_max_vector;
 356         } else if (cur_max_vector > max_vector && UseSubwordForMaxVector) {
 357           // Analyse subword in the loop to set maximum vector size to take advantage of full vector width for subword types.
 358           // Here we analyze if narrowing is likely to happen and if it is we set vector size more aggressively.
 359           // We check for possibility of narrowing by looking through chain operations using subword types.
 360           if (is_subword_type(bt)) {
 361             uint start, end;
 362             VectorNode::vector_operands(n, &start, &end);
 363 
 364             for (uint j = start; j < end; j++) {
 365               Node* in = n->in(j);
 366               // Don't propagate through a memory
 367               if (!in->is_Mem() && in_bb(in) && in->bottom_type()->basic_type() == T_INT) {
 368                 bool same_type = true;
 369                 for (DUIterator_Fast kmax, k = in->fast_outs(kmax); k < kmax; k++) {
 370                   Node *use = in->fast_out(k);
 371                   if (!in_bb(use) && use->bottom_type()->basic_type() != bt) {
 372                     same_type = false;
 373                     break;
 374                   }
 375                 }
 376                 if (same_type) {
 377                   max_vector = cur_max_vector;
 378                   flag_small_bt = true;
 379                 }
 380               }
 381             }
 382           }
 383         }
 384         // We only process post loops on predicated targets where we want to
 385         // mask map the loop to a single iteration
 386         if (post_loop_allowed) {
 387           _post_block.at_put_grow(rpo_idx++, n);
 388         }
 389       }
 390     }
 391     if (is_slp) {
 392       local_loop_unroll_factor = max_vector;
 393       cl->mark_passed_slp();
 394     }
 395     cl->mark_was_slp();
 396     if (cl->is_main_loop()) {
 397       cl->set_slp_max_unroll(local_loop_unroll_factor);
 398     } else if (post_loop_allowed) {
 399       if (!small_basic_type) {
 400         // avoid replication context for small basic types in programmable masked loops
 401         cl->set_slp_max_unroll(local_loop_unroll_factor);
 402       }
 403     }
 404   }
 405 }
 406 
 407 //------------------------------SLP_extract---------------------------
 408 // Extract the superword level parallelism
 409 //
 410 // 1) A reverse post-order of nodes in the block is constructed.  By scanning
 411 //    this list from first to last, all definitions are visited before their uses.
 412 //
 413 // 2) A point-to-point dependence graph is constructed between memory references.
 414 //    This simplies the upcoming "independence" checker.
 415 //
 416 // 3) The maximum depth in the node graph from the beginning of the block
 417 //    to each node is computed.  This is used to prune the graph search
 418 //    in the independence checker.
 419 //
 420 // 4) For integer types, the necessary bit width is propagated backwards
 421 //    from stores to allow packed operations on byte, char, and short
 422 //    integers.  This reverses the promotion to type "int" that javac
 423 //    did for operations like: char c1,c2,c3;  c1 = c2 + c3.
 424 //
 425 // 5) One of the memory references is picked to be an aligned vector reference.
 426 //    The pre-loop trip count is adjusted to align this reference in the
 427 //    unrolled body.
 428 //
 429 // 6) The initial set of pack pairs is seeded with memory references.
 430 //
 431 // 7) The set of pack pairs is extended by following use->def and def->use links.
 432 //
 433 // 8) The pairs are combined into vector sized packs.
 434 //
 435 // 9) Reorder the memory slices to co-locate members of the memory packs.
 436 //
 437 // 10) Generate ideal vector nodes for the final set of packs and where necessary,
 438 //    inserting scalar promotion, vector creation from multiple scalars, and
 439 //    extraction of scalar values from vectors.
 440 //
 441 void SuperWord::SLP_extract() {
 442 
 443 #ifndef PRODUCT
 444   if (_do_vector_loop && TraceSuperWord) {
 445     tty->print("SuperWord::SLP_extract\n");
 446     tty->print("input loop\n");
 447     _lpt->dump_head();
 448     _lpt->dump();
 449     for (uint i = 0; i < _lpt->_body.size(); i++) {
 450       _lpt->_body.at(i)->dump();
 451     }
 452   }
 453 #endif
 454   // Ready the block
 455   if (!construct_bb()) {
 456     return; // Exit if no interesting nodes or complex graph.
 457   }
 458 
 459   // build    _dg, _disjoint_ptrs
 460   dependence_graph();
 461 
 462   // compute function depth(Node*)
 463   compute_max_depth();
 464 
 465   CountedLoopNode *cl = lpt()->_head->as_CountedLoop();
 466   bool post_loop_allowed = (PostLoopMultiversioning && Matcher::has_predicated_vectors() && cl->is_post_loop());
 467   if (cl->is_main_loop()) {
 468     if (_do_vector_loop) {
 469       if (mark_generations() != -1) {
 470         hoist_loads_in_graph(); // this only rebuild the graph; all basic structs need rebuild explicitly
 471 
 472         if (!construct_bb()) {
 473           return; // Exit if no interesting nodes or complex graph.
 474         }
 475         dependence_graph();
 476         compute_max_depth();
 477       }
 478 
 479 #ifndef PRODUCT
 480       if (TraceSuperWord) {
 481         tty->print_cr("\nSuperWord::_do_vector_loop: graph after hoist_loads_in_graph");
 482         _lpt->dump_head();
 483         for (int j = 0; j < _block.length(); j++) {
 484           Node* n = _block.at(j);
 485           int d = depth(n);
 486           for (int i = 0; i < d; i++) tty->print("%s", "  ");
 487           tty->print("%d :", d);
 488           n->dump();
 489         }
 490       }
 491 #endif
 492     }
 493 
 494     compute_vector_element_type();
 495 
 496     // Attempt vectorization
 497 
 498     find_adjacent_refs();
 499 
 500     extend_packlist();
 501 
 502     if (_do_vector_loop) {
 503       if (_packset.length() == 0) {
 504         if (TraceSuperWord) {
 505           tty->print_cr("\nSuperWord::_do_vector_loop DFA could not build packset, now trying to build anyway");
 506         }
 507         pack_parallel();
 508       }
 509     }
 510 
 511     combine_packs();
 512 
 513     construct_my_pack_map();
 514     if (UseVectorCmov) {
 515       merge_packs_to_cmovd();
 516     }
 517 
 518     filter_packs();
 519 
 520     schedule();
 521   } else if (post_loop_allowed) {
 522     int saved_mapped_unroll_factor = cl->slp_max_unroll();
 523     if (saved_mapped_unroll_factor) {
 524       int vector_mapped_unroll_factor = saved_mapped_unroll_factor;
 525 
 526       // now reset the slp_unroll_factor so that we can check the analysis mapped
 527       // what the vector loop was mapped to
 528       cl->set_slp_max_unroll(0);
 529 
 530       // do the analysis on the post loop
 531       unrolling_analysis(vector_mapped_unroll_factor);
 532 
 533       // if our analyzed loop is a canonical fit, start processing it
 534       if (vector_mapped_unroll_factor == saved_mapped_unroll_factor) {
 535         // now add the vector nodes to packsets
 536         for (int i = 0; i < _post_block.length(); i++) {
 537           Node* n = _post_block.at(i);
 538           Node_List* singleton = new Node_List();
 539           singleton->push(n);
 540           _packset.append(singleton);
 541           set_my_pack(n, singleton);
 542         }
 543 
 544         // map base types for vector usage
 545         compute_vector_element_type();
 546       } else {
 547         return;
 548       }
 549     } else {
 550       // for some reason we could not map the slp analysis state of the vectorized loop
 551       return;
 552     }
 553   }
 554 
 555   output();
 556 }
 557 
 558 //------------------------------find_adjacent_refs---------------------------
 559 // Find the adjacent memory references and create pack pairs for them.
 560 // This is the initial set of packs that will then be extended by
 561 // following use->def and def->use links.  The align positions are
 562 // assigned relative to the reference "align_to_ref"
 563 void SuperWord::find_adjacent_refs() {
 564   // Get list of memory operations
 565   Node_List memops;
 566   for (int i = 0; i < _block.length(); i++) {
 567     Node* n = _block.at(i);
 568     if (n->is_Mem() && !n->is_LoadStore() && in_bb(n) &&
 569         is_java_primitive(n->as_Mem()->memory_type())) {
 570       int align = memory_alignment(n->as_Mem(), 0);
 571       if (align != bottom_align) {
 572         memops.push(n);
 573       }
 574     }
 575   }
 576 
 577   Node_List align_to_refs;
 578   int best_iv_adjustment = 0;
 579   MemNode* best_align_to_mem_ref = NULL;
 580 
 581   while (memops.size() != 0) {
 582     // Find a memory reference to align to.
 583     MemNode* mem_ref = find_align_to_ref(memops);
 584     if (mem_ref == NULL) break;
 585     align_to_refs.push(mem_ref);
 586     int iv_adjustment = get_iv_adjustment(mem_ref);
 587 
 588     if (best_align_to_mem_ref == NULL) {
 589       // Set memory reference which is the best from all memory operations
 590       // to be used for alignment. The pre-loop trip count is modified to align
 591       // this reference to a vector-aligned address.
 592       best_align_to_mem_ref = mem_ref;
 593       best_iv_adjustment = iv_adjustment;
 594       NOT_PRODUCT(find_adjacent_refs_trace_1(best_align_to_mem_ref, best_iv_adjustment);)
 595     }
 596 
 597     SWPointer align_to_ref_p(mem_ref, this, NULL, false);
 598     // Set alignment relative to "align_to_ref" for all related memory operations.
 599     for (int i = memops.size() - 1; i >= 0; i--) {
 600       MemNode* s = memops.at(i)->as_Mem();
 601       if (isomorphic(s, mem_ref) &&
 602            (!_do_vector_loop || same_origin_idx(s, mem_ref))) {
 603         SWPointer p2(s, this, NULL, false);
 604         if (p2.comparable(align_to_ref_p)) {
 605           int align = memory_alignment(s, iv_adjustment);
 606           set_alignment(s, align);
 607         }
 608       }
 609     }
 610 
 611     // Create initial pack pairs of memory operations for which
 612     // alignment is set and vectors will be aligned.
 613     bool create_pack = true;
 614     if (memory_alignment(mem_ref, best_iv_adjustment) == 0 || _do_vector_loop) {
 615       if (!Matcher::misaligned_vectors_ok()) {
 616         int vw = vector_width(mem_ref);
 617         int vw_best = vector_width(best_align_to_mem_ref);
 618         if (vw > vw_best) {
 619           // Do not vectorize a memory access with more elements per vector
 620           // if unaligned memory access is not allowed because number of
 621           // iterations in pre-loop will be not enough to align it.
 622           create_pack = false;
 623         } else {
 624           SWPointer p2(best_align_to_mem_ref, this, NULL, false);
 625           if (align_to_ref_p.invar() != p2.invar()) {
 626             // Do not vectorize memory accesses with different invariants
 627             // if unaligned memory accesses are not allowed.
 628             create_pack = false;
 629           }
 630         }
 631       }
 632     } else {
 633       if (same_velt_type(mem_ref, best_align_to_mem_ref)) {
 634         // Can't allow vectorization of unaligned memory accesses with the
 635         // same type since it could be overlapped accesses to the same array.
 636         create_pack = false;
 637       } else {
 638         // Allow independent (different type) unaligned memory operations
 639         // if HW supports them.
 640         if (!Matcher::misaligned_vectors_ok()) {
 641           create_pack = false;
 642         } else {
 643           // Check if packs of the same memory type but
 644           // with a different alignment were created before.
 645           for (uint i = 0; i < align_to_refs.size(); i++) {
 646             MemNode* mr = align_to_refs.at(i)->as_Mem();
 647             if (same_velt_type(mr, mem_ref) &&
 648                 memory_alignment(mr, iv_adjustment) != 0)
 649               create_pack = false;
 650           }
 651         }
 652       }
 653     }
 654     if (create_pack) {
 655       for (uint i = 0; i < memops.size(); i++) {
 656         Node* s1 = memops.at(i);
 657         int align = alignment(s1);
 658         if (align == top_align) continue;
 659         for (uint j = 0; j < memops.size(); j++) {
 660           Node* s2 = memops.at(j);
 661           if (alignment(s2) == top_align) continue;
 662           if (s1 != s2 && are_adjacent_refs(s1, s2)) {
 663             if (stmts_can_pack(s1, s2, align)) {
 664               Node_List* pair = new Node_List();
 665               pair->push(s1);
 666               pair->push(s2);
 667               if (!_do_vector_loop || same_origin_idx(s1, s2)) {
 668                 _packset.append(pair);
 669               }
 670             }
 671           }
 672         }
 673       }
 674     } else { // Don't create unaligned pack
 675       // First, remove remaining memory ops of the same type from the list.
 676       for (int i = memops.size() - 1; i >= 0; i--) {
 677         MemNode* s = memops.at(i)->as_Mem();
 678         if (same_velt_type(s, mem_ref)) {
 679           memops.remove(i);
 680         }
 681       }
 682 
 683       // Second, remove already constructed packs of the same type.
 684       for (int i = _packset.length() - 1; i >= 0; i--) {
 685         Node_List* p = _packset.at(i);
 686         MemNode* s = p->at(0)->as_Mem();
 687         if (same_velt_type(s, mem_ref)) {
 688           remove_pack_at(i);
 689         }
 690       }
 691 
 692       // If needed find the best memory reference for loop alignment again.
 693       if (same_velt_type(mem_ref, best_align_to_mem_ref)) {
 694         // Put memory ops from remaining packs back on memops list for
 695         // the best alignment search.
 696         uint orig_msize = memops.size();
 697         for (int i = 0; i < _packset.length(); i++) {
 698           Node_List* p = _packset.at(i);
 699           MemNode* s = p->at(0)->as_Mem();
 700           assert(!same_velt_type(s, mem_ref), "sanity");
 701           memops.push(s);
 702         }
 703         best_align_to_mem_ref = find_align_to_ref(memops);
 704         if (best_align_to_mem_ref == NULL) {
 705           if (TraceSuperWord) {
 706             tty->print_cr("SuperWord::find_adjacent_refs(): best_align_to_mem_ref == NULL");
 707           }
 708           break;
 709         }
 710         best_iv_adjustment = get_iv_adjustment(best_align_to_mem_ref);
 711         NOT_PRODUCT(find_adjacent_refs_trace_1(best_align_to_mem_ref, best_iv_adjustment);)
 712         // Restore list.
 713         while (memops.size() > orig_msize)
 714           (void)memops.pop();
 715       }
 716     } // unaligned memory accesses
 717 
 718     // Remove used mem nodes.
 719     for (int i = memops.size() - 1; i >= 0; i--) {
 720       MemNode* m = memops.at(i)->as_Mem();
 721       if (alignment(m) != top_align) {
 722         memops.remove(i);
 723       }
 724     }
 725 
 726   } // while (memops.size() != 0
 727   set_align_to_ref(best_align_to_mem_ref);
 728 
 729   if (TraceSuperWord) {
 730     tty->print_cr("\nAfter find_adjacent_refs");
 731     print_packset();
 732   }
 733 }
 734 
 735 #ifndef PRODUCT
 736 void SuperWord::find_adjacent_refs_trace_1(Node* best_align_to_mem_ref, int best_iv_adjustment) {
 737   if (is_trace_adjacent()) {
 738     tty->print("SuperWord::find_adjacent_refs best_align_to_mem_ref = %d, best_iv_adjustment = %d",
 739        best_align_to_mem_ref->_idx, best_iv_adjustment);
 740        best_align_to_mem_ref->dump();
 741   }
 742 }
 743 #endif
 744 
 745 //------------------------------find_align_to_ref---------------------------
 746 // Find a memory reference to align the loop induction variable to.
 747 // Looks first at stores then at loads, looking for a memory reference
 748 // with the largest number of references similar to it.
 749 MemNode* SuperWord::find_align_to_ref(Node_List &memops) {
 750   GrowableArray<int> cmp_ct(arena(), memops.size(), memops.size(), 0);
 751 
 752   // Count number of comparable memory ops
 753   for (uint i = 0; i < memops.size(); i++) {
 754     MemNode* s1 = memops.at(i)->as_Mem();
 755     SWPointer p1(s1, this, NULL, false);
 756     // Discard if pre loop can't align this reference
 757     if (!ref_is_alignable(p1)) {
 758       *cmp_ct.adr_at(i) = 0;
 759       continue;
 760     }
 761     for (uint j = i+1; j < memops.size(); j++) {
 762       MemNode* s2 = memops.at(j)->as_Mem();
 763       if (isomorphic(s1, s2)) {
 764         SWPointer p2(s2, this, NULL, false);
 765         if (p1.comparable(p2)) {
 766           (*cmp_ct.adr_at(i))++;
 767           (*cmp_ct.adr_at(j))++;
 768         }
 769       }
 770     }
 771   }
 772 
 773   // Find Store (or Load) with the greatest number of "comparable" references,
 774   // biggest vector size, smallest data size and smallest iv offset.
 775   int max_ct        = 0;
 776   int max_vw        = 0;
 777   int max_idx       = -1;
 778   int min_size      = max_jint;
 779   int min_iv_offset = max_jint;
 780   for (uint j = 0; j < memops.size(); j++) {
 781     MemNode* s = memops.at(j)->as_Mem();
 782     if (s->is_Store()) {
 783       int vw = vector_width_in_bytes(s);
 784       assert(vw > 1, "sanity");
 785       SWPointer p(s, this, NULL, false);
 786       if ( cmp_ct.at(j) >  max_ct ||
 787           (cmp_ct.at(j) == max_ct &&
 788             ( vw >  max_vw ||
 789              (vw == max_vw &&
 790               ( data_size(s) <  min_size ||
 791                (data_size(s) == min_size &&
 792                 p.offset_in_bytes() < min_iv_offset)))))) {
 793         max_ct = cmp_ct.at(j);
 794         max_vw = vw;
 795         max_idx = j;
 796         min_size = data_size(s);
 797         min_iv_offset = p.offset_in_bytes();
 798       }
 799     }
 800   }
 801   // If no stores, look at loads
 802   if (max_ct == 0) {
 803     for (uint j = 0; j < memops.size(); j++) {
 804       MemNode* s = memops.at(j)->as_Mem();
 805       if (s->is_Load()) {
 806         int vw = vector_width_in_bytes(s);
 807         assert(vw > 1, "sanity");
 808         SWPointer p(s, this, NULL, false);
 809         if ( cmp_ct.at(j) >  max_ct ||
 810             (cmp_ct.at(j) == max_ct &&
 811               ( vw >  max_vw ||
 812                (vw == max_vw &&
 813                 ( data_size(s) <  min_size ||
 814                  (data_size(s) == min_size &&
 815                   p.offset_in_bytes() < min_iv_offset)))))) {
 816           max_ct = cmp_ct.at(j);
 817           max_vw = vw;
 818           max_idx = j;
 819           min_size = data_size(s);
 820           min_iv_offset = p.offset_in_bytes();
 821         }
 822       }
 823     }
 824   }
 825 
 826 #ifdef ASSERT
 827   if (TraceSuperWord && Verbose) {
 828     tty->print_cr("\nVector memops after find_align_to_ref");
 829     for (uint i = 0; i < memops.size(); i++) {
 830       MemNode* s = memops.at(i)->as_Mem();
 831       s->dump();
 832     }
 833   }
 834 #endif
 835 
 836   if (max_ct > 0) {
 837 #ifdef ASSERT
 838     if (TraceSuperWord) {
 839       tty->print("\nVector align to node: ");
 840       memops.at(max_idx)->as_Mem()->dump();
 841     }
 842 #endif
 843     return memops.at(max_idx)->as_Mem();
 844   }
 845   return NULL;
 846 }
 847 
 848 //------------------------------ref_is_alignable---------------------------
 849 // Can the preloop align the reference to position zero in the vector?
 850 bool SuperWord::ref_is_alignable(SWPointer& p) {
 851   if (!p.has_iv()) {
 852     return true;   // no induction variable
 853   }
 854   CountedLoopEndNode* pre_end = get_pre_loop_end(lp()->as_CountedLoop());
 855   assert(pre_end != NULL, "we must have a correct pre-loop");
 856   assert(pre_end->stride_is_con(), "pre loop stride is constant");
 857   int preloop_stride = pre_end->stride_con();
 858 
 859   int span = preloop_stride * p.scale_in_bytes();
 860   int mem_size = p.memory_size();
 861   int offset   = p.offset_in_bytes();
 862   // Stride one accesses are alignable if offset is aligned to memory operation size.
 863   // Offset can be unaligned when UseUnalignedAccesses is used.
 864   if (ABS(span) == mem_size && (ABS(offset) % mem_size) == 0) {
 865     return true;
 866   }
 867   // If the initial offset from start of the object is computable,
 868   // check if the pre-loop can align the final offset accordingly.
 869   //
 870   // In other words: Can we find an i such that the offset
 871   // after i pre-loop iterations is aligned to vw?
 872   //   (init_offset + pre_loop) % vw == 0              (1)
 873   // where
 874   //   pre_loop = i * span
 875   // is the number of bytes added to the offset by i pre-loop iterations.
 876   //
 877   // For this to hold we need pre_loop to increase init_offset by
 878   //   pre_loop = vw - (init_offset % vw)
 879   //
 880   // This is only possible if pre_loop is divisible by span because each
 881   // pre-loop iteration increases the initial offset by 'span' bytes:
 882   //   (vw - (init_offset % vw)) % span == 0
 883   //
 884   int vw = vector_width_in_bytes(p.mem());
 885   assert(vw > 1, "sanity");
 886   Node* init_nd = pre_end->init_trip();
 887   if (init_nd->is_Con() && p.invar() == NULL) {
 888     int init = init_nd->bottom_type()->is_int()->get_con();
 889     int init_offset = init * p.scale_in_bytes() + offset;
 890     assert(init_offset >= 0, "positive offset from object start");
 891     if (vw % span == 0) {
 892       // If vm is a multiple of span, we use formula (1).
 893       if (span > 0) {
 894         return (vw - (init_offset % vw)) % span == 0;
 895       } else {
 896         assert(span < 0, "nonzero stride * scale");
 897         return (init_offset % vw) % -span == 0;
 898       }
 899     } else if (span % vw == 0) {
 900       // If span is a multiple of vw, we can simplify formula (1) to:
 901       //   (init_offset + i * span) % vw == 0
 902       //     =>
 903       //   (init_offset % vw) + ((i * span) % vw) == 0
 904       //     =>
 905       //   init_offset % vw == 0
 906       //
 907       // Because we add a multiple of vw to the initial offset, the final
 908       // offset is a multiple of vw if and only if init_offset is a multiple.
 909       //
 910       return (init_offset % vw) == 0;
 911     }
 912   }
 913   return false;
 914 }
 915 
 916 //---------------------------get_iv_adjustment---------------------------
 917 // Calculate loop's iv adjustment for this memory ops.
 918 int SuperWord::get_iv_adjustment(MemNode* mem_ref) {
 919   SWPointer align_to_ref_p(mem_ref, this, NULL, false);
 920   int offset = align_to_ref_p.offset_in_bytes();
 921   int scale  = align_to_ref_p.scale_in_bytes();
 922   int elt_size = align_to_ref_p.memory_size();
 923   int vw       = vector_width_in_bytes(mem_ref);
 924   assert(vw > 1, "sanity");
 925   int iv_adjustment;
 926   if (scale != 0) {
 927     int stride_sign = (scale * iv_stride()) > 0 ? 1 : -1;
 928     // At least one iteration is executed in pre-loop by default. As result
 929     // several iterations are needed to align memory operations in main-loop even
 930     // if offset is 0.
 931     int iv_adjustment_in_bytes = (stride_sign * vw - (offset % vw));
 932     assert(((ABS(iv_adjustment_in_bytes) % elt_size) == 0),
 933            "(%d) should be divisible by (%d)", iv_adjustment_in_bytes, elt_size);
 934     iv_adjustment = iv_adjustment_in_bytes/elt_size;
 935   } else {
 936     // This memory op is not dependent on iv (scale == 0)
 937     iv_adjustment = 0;
 938   }
 939 
 940 #ifndef PRODUCT
 941   if (TraceSuperWord) {
 942     tty->print("SuperWord::get_iv_adjustment: n = %d, noffset = %d iv_adjust = %d elt_size = %d scale = %d iv_stride = %d vect_size %d: ",
 943       mem_ref->_idx, offset, iv_adjustment, elt_size, scale, iv_stride(), vw);
 944     mem_ref->dump();
 945   }
 946 #endif
 947   return iv_adjustment;
 948 }
 949 
 950 //---------------------------dependence_graph---------------------------
 951 // Construct dependency graph.
 952 // Add dependence edges to load/store nodes for memory dependence
 953 //    A.out()->DependNode.in(1) and DependNode.out()->B.prec(x)
 954 void SuperWord::dependence_graph() {
 955   CountedLoopNode *cl = lpt()->_head->as_CountedLoop();
 956   // First, assign a dependence node to each memory node
 957   for (int i = 0; i < _block.length(); i++ ) {
 958     Node *n = _block.at(i);
 959     if (n->is_Mem() || (n->is_Phi() && n->bottom_type() == Type::MEMORY)) {
 960       _dg.make_node(n);
 961     }
 962   }
 963 
 964   // For each memory slice, create the dependences
 965   for (int i = 0; i < _mem_slice_head.length(); i++) {
 966     Node* n      = _mem_slice_head.at(i);
 967     Node* n_tail = _mem_slice_tail.at(i);
 968 
 969     // Get slice in predecessor order (last is first)
 970     if (cl->is_main_loop()) {
 971       mem_slice_preds(n_tail, n, _nlist);
 972     }
 973 
 974 #ifndef PRODUCT
 975     if(TraceSuperWord && Verbose) {
 976       tty->print_cr("SuperWord::dependence_graph: built a new mem slice");
 977       for (int j = _nlist.length() - 1; j >= 0 ; j--) {
 978         _nlist.at(j)->dump();
 979       }
 980     }
 981 #endif
 982     // Make the slice dependent on the root
 983     DepMem* slice = _dg.dep(n);
 984     _dg.make_edge(_dg.root(), slice);
 985 
 986     // Create a sink for the slice
 987     DepMem* slice_sink = _dg.make_node(NULL);
 988     _dg.make_edge(slice_sink, _dg.tail());
 989 
 990     // Now visit each pair of memory ops, creating the edges
 991     for (int j = _nlist.length() - 1; j >= 0 ; j--) {
 992       Node* s1 = _nlist.at(j);
 993 
 994       // If no dependency yet, use slice
 995       if (_dg.dep(s1)->in_cnt() == 0) {
 996         _dg.make_edge(slice, s1);
 997       }
 998       SWPointer p1(s1->as_Mem(), this, NULL, false);
 999       bool sink_dependent = true;
1000       for (int k = j - 1; k >= 0; k--) {
1001         Node* s2 = _nlist.at(k);
1002         if (s1->is_Load() && s2->is_Load())
1003           continue;
1004         SWPointer p2(s2->as_Mem(), this, NULL, false);
1005 
1006         int cmp = p1.cmp(p2);
1007         if (SuperWordRTDepCheck &&
1008             p1.base() != p2.base() && p1.valid() && p2.valid()) {
1009           // Create a runtime check to disambiguate
1010           OrderedPair pp(p1.base(), p2.base());
1011           _disjoint_ptrs.append_if_missing(pp);
1012         } else if (!SWPointer::not_equal(cmp)) {
1013           // Possibly same address
1014           _dg.make_edge(s1, s2);
1015           sink_dependent = false;
1016         }
1017       }
1018       if (sink_dependent) {
1019         _dg.make_edge(s1, slice_sink);
1020       }
1021     }
1022 
1023     if (TraceSuperWord) {
1024       tty->print_cr("\nDependence graph for slice: %d", n->_idx);
1025       for (int q = 0; q < _nlist.length(); q++) {
1026         _dg.print(_nlist.at(q));
1027       }
1028       tty->cr();
1029     }
1030 
1031     _nlist.clear();
1032   }
1033 
1034   if (TraceSuperWord) {
1035     tty->print_cr("\ndisjoint_ptrs: %s", _disjoint_ptrs.length() > 0 ? "" : "NONE");
1036     for (int r = 0; r < _disjoint_ptrs.length(); r++) {
1037       _disjoint_ptrs.at(r).print();
1038       tty->cr();
1039     }
1040     tty->cr();
1041   }
1042 
1043 }
1044 
1045 //---------------------------mem_slice_preds---------------------------
1046 // Return a memory slice (node list) in predecessor order starting at "start"
1047 void SuperWord::mem_slice_preds(Node* start, Node* stop, GrowableArray<Node*> &preds) {
1048   assert(preds.length() == 0, "start empty");
1049   Node* n = start;
1050   Node* prev = NULL;
1051   while (true) {
1052     NOT_PRODUCT( if(is_trace_mem_slice()) tty->print_cr("SuperWord::mem_slice_preds: n %d", n->_idx);)
1053     assert(in_bb(n), "must be in block");
1054     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1055       Node* out = n->fast_out(i);
1056       if (out->is_Load()) {
1057         if (in_bb(out)) {
1058           preds.push(out);
1059           if (TraceSuperWord && Verbose) {
1060             tty->print_cr("SuperWord::mem_slice_preds: added pred(%d)", out->_idx);
1061           }
1062         }
1063       } else {
1064         // FIXME
1065         if (out->is_MergeMem() && !in_bb(out)) {
1066           // Either unrolling is causing a memory edge not to disappear,
1067           // or need to run igvn.optimize() again before SLP
1068         } else if (out->is_Phi() && out->bottom_type() == Type::MEMORY && !in_bb(out)) {
1069           // Ditto.  Not sure what else to check further.
1070         } else if (out->Opcode() == Op_StoreCM && out->in(MemNode::OopStore) == n) {
1071           // StoreCM has an input edge used as a precedence edge.
1072           // Maybe an issue when oop stores are vectorized.
1073         } else {
1074           assert(out == prev || prev == NULL, "no branches off of store slice");
1075         }
1076       }//else
1077     }//for
1078     if (n == stop) break;
1079     preds.push(n);
1080     if (TraceSuperWord && Verbose) {
1081       tty->print_cr("SuperWord::mem_slice_preds: added pred(%d)", n->_idx);
1082     }
1083     prev = n;
1084     assert(n->is_Mem(), "unexpected node %s", n->Name());
1085     n = n->in(MemNode::Memory);
1086   }
1087 }
1088 
1089 //------------------------------stmts_can_pack---------------------------
1090 // Can s1 and s2 be in a pack with s1 immediately preceding s2 and
1091 // s1 aligned at "align"
1092 bool SuperWord::stmts_can_pack(Node* s1, Node* s2, int align) {
1093 
1094   // Do not use superword for non-primitives
1095   BasicType bt1 = velt_basic_type(s1);
1096   BasicType bt2 = velt_basic_type(s2);
1097   if(!is_java_primitive(bt1) || !is_java_primitive(bt2))
1098     return false;
1099   if (Matcher::max_vector_size(bt1) < 2) {
1100     return false; // No vectors for this type
1101   }
1102 
1103   if (isomorphic(s1, s2)) {
1104     if ((independent(s1, s2) && have_similar_inputs(s1, s2)) || reduction(s1, s2)) {
1105       if (!exists_at(s1, 0) && !exists_at(s2, 1)) {
1106         if (!s1->is_Mem() || are_adjacent_refs(s1, s2)) {
1107           int s1_align = alignment(s1);
1108           int s2_align = alignment(s2);
1109           if (s1_align == top_align || s1_align == align) {
1110             if (s2_align == top_align || s2_align == align + data_size(s1)) {
1111               return true;
1112             }
1113           }
1114         }
1115       }
1116     }
1117   }
1118   return false;
1119 }
1120 
1121 //------------------------------exists_at---------------------------
1122 // Does s exist in a pack at position pos?
1123 bool SuperWord::exists_at(Node* s, uint pos) {
1124   for (int i = 0; i < _packset.length(); i++) {
1125     Node_List* p = _packset.at(i);
1126     if (p->at(pos) == s) {
1127       return true;
1128     }
1129   }
1130   return false;
1131 }
1132 
1133 //------------------------------are_adjacent_refs---------------------------
1134 // Is s1 immediately before s2 in memory?
1135 bool SuperWord::are_adjacent_refs(Node* s1, Node* s2) {
1136   if (!s1->is_Mem() || !s2->is_Mem()) return false;
1137   if (!in_bb(s1)    || !in_bb(s2))    return false;
1138 
1139   // Do not use superword for non-primitives
1140   if (!is_java_primitive(s1->as_Mem()->memory_type()) ||
1141       !is_java_primitive(s2->as_Mem()->memory_type())) {
1142     return false;
1143   }
1144 
1145   // FIXME - co_locate_pack fails on Stores in different mem-slices, so
1146   // only pack memops that are in the same alias set until that's fixed.
1147   if (_phase->C->get_alias_index(s1->as_Mem()->adr_type()) !=
1148       _phase->C->get_alias_index(s2->as_Mem()->adr_type()))
1149     return false;
1150   SWPointer p1(s1->as_Mem(), this, NULL, false);
1151   SWPointer p2(s2->as_Mem(), this, NULL, false);
1152   if (p1.base() != p2.base() || !p1.comparable(p2)) return false;
1153   int diff = p2.offset_in_bytes() - p1.offset_in_bytes();
1154   return diff == data_size(s1);
1155 }
1156 
1157 //------------------------------isomorphic---------------------------
1158 // Are s1 and s2 similar?
1159 bool SuperWord::isomorphic(Node* s1, Node* s2) {
1160   if (s1->Opcode() != s2->Opcode()) return false;
1161   if (s1->req() != s2->req()) return false;
1162   if (s1->in(0) != s2->in(0)) return false;
1163   if (!same_velt_type(s1, s2)) return false;
1164   return true;
1165 }
1166 
1167 //------------------------------independent---------------------------
1168 // Is there no data path from s1 to s2 or s2 to s1?
1169 bool SuperWord::independent(Node* s1, Node* s2) {
1170   //  assert(s1->Opcode() == s2->Opcode(), "check isomorphic first");
1171   int d1 = depth(s1);
1172   int d2 = depth(s2);
1173   if (d1 == d2) return s1 != s2;
1174   Node* deep    = d1 > d2 ? s1 : s2;
1175   Node* shallow = d1 > d2 ? s2 : s1;
1176 
1177   visited_clear();
1178 
1179   return independent_path(shallow, deep);
1180 }
1181 
1182 //--------------------------have_similar_inputs-----------------------
1183 // For a node pair (s1, s2) which is isomorphic and independent,
1184 // do s1 and s2 have similar input edges?
1185 bool SuperWord::have_similar_inputs(Node* s1, Node* s2) {
1186   // assert(isomorphic(s1, s2) == true, "check isomorphic");
1187   // assert(independent(s1, s2) == true, "check independent");
1188   if (s1->req() > 1 && !s1->is_Store() && !s1->is_Load()) {
1189     for (uint i = 1; i < s1->req(); i++) {
1190       if (s1->in(i)->Opcode() != s2->in(i)->Opcode()) return false;
1191     }
1192   }
1193   return true;
1194 }
1195 
1196 //------------------------------reduction---------------------------
1197 // Is there a data path between s1 and s2 and the nodes reductions?
1198 bool SuperWord::reduction(Node* s1, Node* s2) {
1199   bool retValue = false;
1200   int d1 = depth(s1);
1201   int d2 = depth(s2);
1202   if (d1 + 1 == d2) {
1203     if (s1->is_reduction() && s2->is_reduction()) {
1204       // This is an ordered set, so s1 should define s2
1205       for (DUIterator_Fast imax, i = s1->fast_outs(imax); i < imax; i++) {
1206         Node* t1 = s1->fast_out(i);
1207         if (t1 == s2) {
1208           // both nodes are reductions and connected
1209           retValue = true;
1210         }
1211       }
1212     }
1213   }
1214 
1215   return retValue;
1216 }
1217 
1218 //------------------------------independent_path------------------------------
1219 // Helper for independent
1220 bool SuperWord::independent_path(Node* shallow, Node* deep, uint dp) {
1221   if (dp >= 1000) return false; // stop deep recursion
1222   visited_set(deep);
1223   int shal_depth = depth(shallow);
1224   assert(shal_depth <= depth(deep), "must be");
1225   for (DepPreds preds(deep, _dg); !preds.done(); preds.next()) {
1226     Node* pred = preds.current();
1227     if (in_bb(pred) && !visited_test(pred)) {
1228       if (shallow == pred) {
1229         return false;
1230       }
1231       if (shal_depth < depth(pred) && !independent_path(shallow, pred, dp+1)) {
1232         return false;
1233       }
1234     }
1235   }
1236   return true;
1237 }
1238 
1239 //------------------------------set_alignment---------------------------
1240 void SuperWord::set_alignment(Node* s1, Node* s2, int align) {
1241   set_alignment(s1, align);
1242   if (align == top_align || align == bottom_align) {
1243     set_alignment(s2, align);
1244   } else {
1245     set_alignment(s2, align + data_size(s1));
1246   }
1247 }
1248 
1249 //------------------------------data_size---------------------------
1250 int SuperWord::data_size(Node* s) {
1251   Node* use = NULL; //test if the node is a candidate for CMoveV optimization, then return the size of CMov
1252   if (UseVectorCmov) {
1253     use = _cmovev_kit.is_Bool_candidate(s);
1254     if (use != NULL) {
1255       return data_size(use);
1256     }
1257     use = _cmovev_kit.is_CmpD_candidate(s);
1258     if (use != NULL) {
1259       return data_size(use);
1260     }
1261   }
1262 
1263   int bsize = type2aelembytes(velt_basic_type(s));
1264   assert(bsize != 0, "valid size");
1265   return bsize;
1266 }
1267 
1268 //------------------------------extend_packlist---------------------------
1269 // Extend packset by following use->def and def->use links from pack members.
1270 void SuperWord::extend_packlist() {
1271   bool changed;
1272   do {
1273     packset_sort(_packset.length());
1274     changed = false;
1275     for (int i = 0; i < _packset.length(); i++) {
1276       Node_List* p = _packset.at(i);
1277       changed |= follow_use_defs(p);
1278       changed |= follow_def_uses(p);
1279     }
1280   } while (changed);
1281 
1282   if (_race_possible) {
1283     for (int i = 0; i < _packset.length(); i++) {
1284       Node_List* p = _packset.at(i);
1285       order_def_uses(p);
1286     }
1287   }
1288 
1289   if (TraceSuperWord) {
1290     tty->print_cr("\nAfter extend_packlist");
1291     print_packset();
1292   }
1293 }
1294 
1295 //------------------------------follow_use_defs---------------------------
1296 // Extend the packset by visiting operand definitions of nodes in pack p
1297 bool SuperWord::follow_use_defs(Node_List* p) {
1298   assert(p->size() == 2, "just checking");
1299   Node* s1 = p->at(0);
1300   Node* s2 = p->at(1);
1301   assert(s1->req() == s2->req(), "just checking");
1302   assert(alignment(s1) + data_size(s1) == alignment(s2), "just checking");
1303 
1304   if (s1->is_Load()) return false;
1305 
1306   int align = alignment(s1);
1307   NOT_PRODUCT(if(is_trace_alignment()) tty->print_cr("SuperWord::follow_use_defs: s1 %d, align %d", s1->_idx, align);)
1308   bool changed = false;
1309   int start = s1->is_Store() ? MemNode::ValueIn   : 1;
1310   int end   = s1->is_Store() ? MemNode::ValueIn+1 : s1->req();
1311   for (int j = start; j < end; j++) {
1312     Node* t1 = s1->in(j);
1313     Node* t2 = s2->in(j);
1314     if (!in_bb(t1) || !in_bb(t2))
1315       continue;
1316     if (stmts_can_pack(t1, t2, align)) {
1317       if (est_savings(t1, t2) >= 0) {
1318         Node_List* pair = new Node_List();
1319         pair->push(t1);
1320         pair->push(t2);
1321         _packset.append(pair);
1322         NOT_PRODUCT(if(is_trace_alignment()) tty->print_cr("SuperWord::follow_use_defs: set_alignment(%d, %d, %d)", t1->_idx, t2->_idx, align);)
1323         set_alignment(t1, t2, align);
1324         changed = true;
1325       }
1326     }
1327   }
1328   return changed;
1329 }
1330 
1331 //------------------------------follow_def_uses---------------------------
1332 // Extend the packset by visiting uses of nodes in pack p
1333 bool SuperWord::follow_def_uses(Node_List* p) {
1334   bool changed = false;
1335   Node* s1 = p->at(0);
1336   Node* s2 = p->at(1);
1337   assert(p->size() == 2, "just checking");
1338   assert(s1->req() == s2->req(), "just checking");
1339   assert(alignment(s1) + data_size(s1) == alignment(s2), "just checking");
1340 
1341   if (s1->is_Store()) return false;
1342 
1343   int align = alignment(s1);
1344   NOT_PRODUCT(if(is_trace_alignment()) tty->print_cr("SuperWord::follow_def_uses: s1 %d, align %d", s1->_idx, align);)
1345   int savings = -1;
1346   int num_s1_uses = 0;
1347   Node* u1 = NULL;
1348   Node* u2 = NULL;
1349   for (DUIterator_Fast imax, i = s1->fast_outs(imax); i < imax; i++) {
1350     Node* t1 = s1->fast_out(i);
1351     num_s1_uses++;
1352     if (!in_bb(t1)) continue;
1353     for (DUIterator_Fast jmax, j = s2->fast_outs(jmax); j < jmax; j++) {
1354       Node* t2 = s2->fast_out(j);
1355       if (!in_bb(t2)) continue;
1356       if (t2->Opcode() == Op_AddI && t2 == _lp->as_CountedLoop()->incr()) continue; // don't mess with the iv
1357       if (!opnd_positions_match(s1, t1, s2, t2))
1358         continue;
1359       if (stmts_can_pack(t1, t2, align)) {
1360         int my_savings = est_savings(t1, t2);
1361         if (my_savings > savings) {
1362           savings = my_savings;
1363           u1 = t1;
1364           u2 = t2;
1365         }
1366       }
1367     }
1368   }
1369   if (num_s1_uses > 1) {
1370     _race_possible = true;
1371   }
1372   if (savings >= 0) {
1373     Node_List* pair = new Node_List();
1374     pair->push(u1);
1375     pair->push(u2);
1376     _packset.append(pair);
1377     NOT_PRODUCT(if(is_trace_alignment()) tty->print_cr("SuperWord::follow_def_uses: set_alignment(%d, %d, %d)", u1->_idx, u2->_idx, align);)
1378     set_alignment(u1, u2, align);
1379     changed = true;
1380   }
1381   return changed;
1382 }
1383 
1384 //------------------------------order_def_uses---------------------------
1385 // For extended packsets, ordinally arrange uses packset by major component
1386 void SuperWord::order_def_uses(Node_List* p) {
1387   Node* s1 = p->at(0);
1388 
1389   if (s1->is_Store()) return;
1390 
1391   // reductions are always managed beforehand
1392   if (s1->is_reduction()) return;
1393 
1394   for (DUIterator_Fast imax, i = s1->fast_outs(imax); i < imax; i++) {
1395     Node* t1 = s1->fast_out(i);
1396 
1397     // Only allow operand swap on commuting operations
1398     if (!t1->is_Add() && !t1->is_Mul()) {
1399       break;
1400     }
1401 
1402     // Now find t1's packset
1403     Node_List* p2 = NULL;
1404     for (int j = 0; j < _packset.length(); j++) {
1405       p2 = _packset.at(j);
1406       Node* first = p2->at(0);
1407       if (t1 == first) {
1408         break;
1409       }
1410       p2 = NULL;
1411     }
1412     // Arrange all sub components by the major component
1413     if (p2 != NULL) {
1414       for (uint j = 1; j < p->size(); j++) {
1415         Node* d1 = p->at(j);
1416         Node* u1 = p2->at(j);
1417         opnd_positions_match(s1, t1, d1, u1);
1418       }
1419     }
1420   }
1421 }
1422 
1423 //---------------------------opnd_positions_match-------------------------
1424 // Is the use of d1 in u1 at the same operand position as d2 in u2?
1425 bool SuperWord::opnd_positions_match(Node* d1, Node* u1, Node* d2, Node* u2) {
1426   // check reductions to see if they are marshalled to represent the reduction
1427   // operator in a specified opnd
1428   if (u1->is_reduction() && u2->is_reduction()) {
1429     // ensure reductions have phis and reduction definitions feeding the 1st operand
1430     Node* first = u1->in(2);
1431     if (first->is_Phi() || first->is_reduction()) {
1432       u1->swap_edges(1, 2);
1433     }
1434     // ensure reductions have phis and reduction definitions feeding the 1st operand
1435     first = u2->in(2);
1436     if (first->is_Phi() || first->is_reduction()) {
1437       u2->swap_edges(1, 2);
1438     }
1439     return true;
1440   }
1441 
1442   uint ct = u1->req();
1443   if (ct != u2->req()) return false;
1444   uint i1 = 0;
1445   uint i2 = 0;
1446   do {
1447     for (i1++; i1 < ct; i1++) if (u1->in(i1) == d1) break;
1448     for (i2++; i2 < ct; i2++) if (u2->in(i2) == d2) break;
1449     if (i1 != i2) {
1450       if ((i1 == (3-i2)) && (u2->is_Add() || u2->is_Mul())) {
1451         // Further analysis relies on operands position matching.
1452         u2->swap_edges(i1, i2);
1453       } else {
1454         return false;
1455       }
1456     }
1457   } while (i1 < ct);
1458   return true;
1459 }
1460 
1461 //------------------------------est_savings---------------------------
1462 // Estimate the savings from executing s1 and s2 as a pack
1463 int SuperWord::est_savings(Node* s1, Node* s2) {
1464   int save_in = 2 - 1; // 2 operations per instruction in packed form
1465 
1466   // inputs
1467   for (uint i = 1; i < s1->req(); i++) {
1468     Node* x1 = s1->in(i);
1469     Node* x2 = s2->in(i);
1470     if (x1 != x2) {
1471       if (are_adjacent_refs(x1, x2)) {
1472         save_in += adjacent_profit(x1, x2);
1473       } else if (!in_packset(x1, x2)) {
1474         save_in -= pack_cost(2);
1475       } else {
1476         save_in += unpack_cost(2);
1477       }
1478     }
1479   }
1480 
1481   // uses of result
1482   uint ct = 0;
1483   int save_use = 0;
1484   for (DUIterator_Fast imax, i = s1->fast_outs(imax); i < imax; i++) {
1485     Node* s1_use = s1->fast_out(i);
1486     for (int j = 0; j < _packset.length(); j++) {
1487       Node_List* p = _packset.at(j);
1488       if (p->at(0) == s1_use) {
1489         for (DUIterator_Fast kmax, k = s2->fast_outs(kmax); k < kmax; k++) {
1490           Node* s2_use = s2->fast_out(k);
1491           if (p->at(p->size()-1) == s2_use) {
1492             ct++;
1493             if (are_adjacent_refs(s1_use, s2_use)) {
1494               save_use += adjacent_profit(s1_use, s2_use);
1495             }
1496           }
1497         }
1498       }
1499     }
1500   }
1501 
1502   if (ct < s1->outcnt()) save_use += unpack_cost(1);
1503   if (ct < s2->outcnt()) save_use += unpack_cost(1);
1504 
1505   return MAX2(save_in, save_use);
1506 }
1507 
1508 //------------------------------costs---------------------------
1509 int SuperWord::adjacent_profit(Node* s1, Node* s2) { return 2; }
1510 int SuperWord::pack_cost(int ct)   { return ct; }
1511 int SuperWord::unpack_cost(int ct) { return ct; }
1512 
1513 //------------------------------combine_packs---------------------------
1514 // Combine packs A and B with A.last == B.first into A.first..,A.last,B.second,..B.last
1515 void SuperWord::combine_packs() {
1516   bool changed = true;
1517   // Combine packs regardless max vector size.
1518   while (changed) {
1519     changed = false;
1520     for (int i = 0; i < _packset.length(); i++) {
1521       Node_List* p1 = _packset.at(i);
1522       if (p1 == NULL) continue;
1523       // Because of sorting we can start at i + 1
1524       for (int j = i + 1; j < _packset.length(); j++) {
1525         Node_List* p2 = _packset.at(j);
1526         if (p2 == NULL) continue;
1527         if (i == j) continue;
1528         if (p1->at(p1->size()-1) == p2->at(0)) {
1529           for (uint k = 1; k < p2->size(); k++) {
1530             p1->push(p2->at(k));
1531           }
1532           _packset.at_put(j, NULL);
1533           changed = true;
1534         }
1535       }
1536     }
1537   }
1538 
1539   // Split packs which have size greater then max vector size.
1540   for (int i = 0; i < _packset.length(); i++) {
1541     Node_List* p1 = _packset.at(i);
1542     if (p1 != NULL) {
1543       BasicType bt = velt_basic_type(p1->at(0));
1544       uint max_vlen = Matcher::max_vector_size(bt); // Max elements in vector
1545       assert(is_power_of_2(max_vlen), "sanity");
1546       uint psize = p1->size();
1547       if (!is_power_of_2(psize)) {
1548         // Skip pack which can't be vector.
1549         // case1: for(...) { a[i] = i; }    elements values are different (i+x)
1550         // case2: for(...) { a[i] = b[i+1]; }  can't align both, load and store
1551         _packset.at_put(i, NULL);
1552         continue;
1553       }
1554       if (psize > max_vlen) {
1555         Node_List* pack = new Node_List();
1556         for (uint j = 0; j < psize; j++) {
1557           pack->push(p1->at(j));
1558           if (pack->size() >= max_vlen) {
1559             assert(is_power_of_2(pack->size()), "sanity");
1560             _packset.append(pack);
1561             pack = new Node_List();
1562           }
1563         }
1564         _packset.at_put(i, NULL);
1565       }
1566     }
1567   }
1568 
1569   // Compress list.
1570   for (int i = _packset.length() - 1; i >= 0; i--) {
1571     Node_List* p1 = _packset.at(i);
1572     if (p1 == NULL) {
1573       _packset.remove_at(i);
1574     }
1575   }
1576 
1577   if (TraceSuperWord) {
1578     tty->print_cr("\nAfter combine_packs");
1579     print_packset();
1580   }
1581 }
1582 
1583 //-----------------------------construct_my_pack_map--------------------------
1584 // Construct the map from nodes to packs.  Only valid after the
1585 // point where a node is only in one pack (after combine_packs).
1586 void SuperWord::construct_my_pack_map() {
1587   Node_List* rslt = NULL;
1588   for (int i = 0; i < _packset.length(); i++) {
1589     Node_List* p = _packset.at(i);
1590     for (uint j = 0; j < p->size(); j++) {
1591       Node* s = p->at(j);
1592       assert(my_pack(s) == NULL, "only in one pack");
1593       set_my_pack(s, p);
1594     }
1595   }
1596 }
1597 
1598 //------------------------------filter_packs---------------------------
1599 // Remove packs that are not implemented or not profitable.
1600 void SuperWord::filter_packs() {
1601   // Remove packs that are not implemented
1602   for (int i = _packset.length() - 1; i >= 0; i--) {
1603     Node_List* pk = _packset.at(i);
1604     bool impl = implemented(pk);
1605     if (!impl) {
1606 #ifndef PRODUCT
1607       if (TraceSuperWord && Verbose) {
1608         tty->print_cr("Unimplemented");
1609         pk->at(0)->dump();
1610       }
1611 #endif
1612       remove_pack_at(i);
1613     }
1614     Node *n = pk->at(0);
1615     if (n->is_reduction()) {
1616       _num_reductions++;
1617     } else {
1618       _num_work_vecs++;
1619     }
1620   }
1621 
1622   // Remove packs that are not profitable
1623   bool changed;
1624   do {
1625     changed = false;
1626     for (int i = _packset.length() - 1; i >= 0; i--) {
1627       Node_List* pk = _packset.at(i);
1628       bool prof = profitable(pk);
1629       if (!prof) {
1630 #ifndef PRODUCT
1631         if (TraceSuperWord && Verbose) {
1632           tty->print_cr("Unprofitable");
1633           pk->at(0)->dump();
1634         }
1635 #endif
1636         remove_pack_at(i);
1637         changed = true;
1638       }
1639     }
1640   } while (changed);
1641 
1642 #ifndef PRODUCT
1643   if (TraceSuperWord) {
1644     tty->print_cr("\nAfter filter_packs");
1645     print_packset();
1646     tty->cr();
1647   }
1648 #endif
1649 }
1650 
1651 //------------------------------merge_packs_to_cmovd---------------------------
1652 // Merge CMoveD into new vector-nodes
1653 // We want to catch this pattern and subsume CmpD and Bool into CMoveD
1654 //
1655 //                   SubD             ConD
1656 //                  /  |               /
1657 //                 /   |           /   /
1658 //                /    |       /      /
1659 //               /     |   /         /
1660 //              /      /            /
1661 //             /    /  |           /
1662 //            v /      |          /
1663 //         CmpD        |         /
1664 //          |          |        /
1665 //          v          |       /
1666 //         Bool        |      /
1667 //           \         |     /
1668 //             \       |    /
1669 //               \     |   /
1670 //                 \   |  /
1671 //                   \ v /
1672 //                   CMoveD
1673 //
1674 
1675 void SuperWord::merge_packs_to_cmovd() {
1676   for (int i = _packset.length() - 1; i >= 0; i--) {
1677     _cmovev_kit.make_cmovevd_pack(_packset.at(i));
1678   }
1679   #ifndef PRODUCT
1680     if (TraceSuperWord) {
1681       tty->print_cr("\nSuperWord::merge_packs_to_cmovd(): After merge");
1682       print_packset();
1683       tty->cr();
1684     }
1685   #endif
1686 }
1687 
1688 Node* CMoveKit::is_Bool_candidate(Node* def) const {
1689   Node* use = NULL;
1690   if (!def->is_Bool() || def->in(0) != NULL || def->outcnt() != 1) {
1691     return NULL;
1692   }
1693   for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
1694     use = def->fast_out(j);
1695     if (!_sw->same_generation(def, use) || !use->is_CMove()) {
1696       return NULL;
1697     }
1698   }
1699   return use;
1700 }
1701 
1702 Node* CMoveKit::is_CmpD_candidate(Node* def) const {
1703   Node* use = NULL;
1704   if (!def->is_Cmp() || def->in(0) != NULL || def->outcnt() != 1) {
1705     return NULL;
1706   }
1707   for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
1708     use = def->fast_out(j);
1709     if (!_sw->same_generation(def, use) || (use = is_Bool_candidate(use)) == NULL || !_sw->same_generation(def, use)) {
1710       return NULL;
1711     }
1712   }
1713   return use;
1714 }
1715 
1716 Node_List* CMoveKit::make_cmovevd_pack(Node_List* cmovd_pk) {
1717   Node *cmovd = cmovd_pk->at(0);
1718   if (!cmovd->is_CMove()) {
1719     return NULL;
1720   }
1721   if (cmovd->Opcode() != Op_CMoveF && cmovd->Opcode() != Op_CMoveD) {
1722     return NULL;
1723   }
1724   if (pack(cmovd) != NULL) { // already in the cmov pack
1725     return NULL;
1726   }
1727   if (cmovd->in(0) != NULL) {
1728     NOT_PRODUCT(if(_sw->is_trace_cmov()) {tty->print("CMoveKit::make_cmovevd_pack: CMoveD %d has control flow, escaping...", cmovd->_idx); cmovd->dump();})
1729     return NULL;
1730   }
1731 
1732   Node* bol = cmovd->as_CMove()->in(CMoveNode::Condition);
1733   if (!bol->is_Bool()
1734       || bol->outcnt() != 1
1735       || !_sw->same_generation(bol, cmovd)
1736       || bol->in(0) != NULL  // BoolNode has control flow!!
1737       || _sw->my_pack(bol) == NULL) {
1738       NOT_PRODUCT(if(_sw->is_trace_cmov()) {tty->print("CMoveKit::make_cmovevd_pack: Bool %d does not fit CMoveD %d for building vector, escaping...", bol->_idx, cmovd->_idx); bol->dump();})
1739       return NULL;
1740   }
1741   Node_List* bool_pk = _sw->my_pack(bol);
1742   if (bool_pk->size() != cmovd_pk->size() ) {
1743     return NULL;
1744   }
1745 
1746   Node* cmpd = bol->in(1);
1747   if (!cmpd->is_Cmp()
1748       || cmpd->outcnt() != 1
1749       || !_sw->same_generation(cmpd, cmovd)
1750       || cmpd->in(0) != NULL  // CmpDNode has control flow!!
1751       || _sw->my_pack(cmpd) == NULL) {
1752       NOT_PRODUCT(if(_sw->is_trace_cmov()) {tty->print("CMoveKit::make_cmovevd_pack: CmpD %d does not fit CMoveD %d for building vector, escaping...", cmpd->_idx, cmovd->_idx); cmpd->dump();})
1753       return NULL;
1754   }
1755   Node_List* cmpd_pk = _sw->my_pack(cmpd);
1756   if (cmpd_pk->size() != cmovd_pk->size() ) {
1757     return NULL;
1758   }
1759 
1760   if (!test_cmpd_pack(cmpd_pk, cmovd_pk)) {
1761     NOT_PRODUCT(if(_sw->is_trace_cmov()) {tty->print("CMoveKit::make_cmovevd_pack: cmpd pack for CmpD %d failed vectorization test", cmpd->_idx); cmpd->dump();})
1762     return NULL;
1763   }
1764 
1765   Node_List* new_cmpd_pk = new Node_List();
1766   uint sz = cmovd_pk->size() - 1;
1767   for (uint i = 0; i <= sz; ++i) {
1768     Node* cmov = cmovd_pk->at(i);
1769     Node* bol  = bool_pk->at(i);
1770     Node* cmp  = cmpd_pk->at(i);
1771 
1772     new_cmpd_pk->insert(i, cmov);
1773 
1774     map(cmov, new_cmpd_pk);
1775     map(bol, new_cmpd_pk);
1776     map(cmp, new_cmpd_pk);
1777 
1778     _sw->set_my_pack(cmov, new_cmpd_pk); // and keep old packs for cmp and bool
1779   }
1780   _sw->_packset.remove(cmovd_pk);
1781   _sw->_packset.remove(bool_pk);
1782   _sw->_packset.remove(cmpd_pk);
1783   _sw->_packset.append(new_cmpd_pk);
1784   NOT_PRODUCT(if(_sw->is_trace_cmov()) {tty->print_cr("CMoveKit::make_cmovevd_pack: added syntactic CMoveD pack"); _sw->print_pack(new_cmpd_pk);})
1785   return new_cmpd_pk;
1786 }
1787 
1788 bool CMoveKit::test_cmpd_pack(Node_List* cmpd_pk, Node_List* cmovd_pk) {
1789   Node* cmpd0 = cmpd_pk->at(0);
1790   assert(cmpd0->is_Cmp(), "CMoveKit::test_cmpd_pack: should be CmpDNode");
1791   assert(cmovd_pk->at(0)->is_CMove(), "CMoveKit::test_cmpd_pack: should be CMoveD");
1792   assert(cmpd_pk->size() == cmovd_pk->size(), "CMoveKit::test_cmpd_pack: should be same size");
1793   Node* in1 = cmpd0->in(1);
1794   Node* in2 = cmpd0->in(2);
1795   Node_List* in1_pk = _sw->my_pack(in1);
1796   Node_List* in2_pk = _sw->my_pack(in2);
1797 
1798   if (  (in1_pk != NULL && in1_pk->size() != cmpd_pk->size())
1799      || (in2_pk != NULL && in2_pk->size() != cmpd_pk->size()) ) {
1800     return false;
1801   }
1802 
1803   // test if "all" in1 are in the same pack or the same node
1804   if (in1_pk == NULL) {
1805     for (uint j = 1; j < cmpd_pk->size(); j++) {
1806       if (cmpd_pk->at(j)->in(1) != in1) {
1807         return false;
1808       }
1809     }//for: in1_pk is not pack but all CmpD nodes in the pack have the same in(1)
1810   }
1811   // test if "all" in2 are in the same pack or the same node
1812   if (in2_pk == NULL) {
1813     for (uint j = 1; j < cmpd_pk->size(); j++) {
1814       if (cmpd_pk->at(j)->in(2) != in2) {
1815         return false;
1816       }
1817     }//for: in2_pk is not pack but all CmpD nodes in the pack have the same in(2)
1818   }
1819   //now check if cmpd_pk may be subsumed in vector built for cmovd_pk
1820   int cmovd_ind1, cmovd_ind2;
1821   if (cmpd_pk->at(0)->in(1) == cmovd_pk->at(0)->as_CMove()->in(CMoveNode::IfFalse)
1822    && cmpd_pk->at(0)->in(2) == cmovd_pk->at(0)->as_CMove()->in(CMoveNode::IfTrue)) {
1823       cmovd_ind1 = CMoveNode::IfFalse;
1824       cmovd_ind2 = CMoveNode::IfTrue;
1825   } else if (cmpd_pk->at(0)->in(2) == cmovd_pk->at(0)->as_CMove()->in(CMoveNode::IfFalse)
1826           && cmpd_pk->at(0)->in(1) == cmovd_pk->at(0)->as_CMove()->in(CMoveNode::IfTrue)) {
1827       cmovd_ind2 = CMoveNode::IfFalse;
1828       cmovd_ind1 = CMoveNode::IfTrue;
1829   }
1830   else {
1831     return false;
1832   }
1833 
1834   for (uint j = 1; j < cmpd_pk->size(); j++) {
1835     if (cmpd_pk->at(j)->in(1) != cmovd_pk->at(j)->as_CMove()->in(cmovd_ind1)
1836         || cmpd_pk->at(j)->in(2) != cmovd_pk->at(j)->as_CMove()->in(cmovd_ind2)) {
1837         return false;
1838     }//if
1839   }
1840   NOT_PRODUCT(if(_sw->is_trace_cmov()) { tty->print("CMoveKit::test_cmpd_pack: cmpd pack for 1st CmpD %d is OK for vectorization: ", cmpd0->_idx); cmpd0->dump(); })
1841   return true;
1842 }
1843 
1844 //------------------------------implemented---------------------------
1845 // Can code be generated for pack p?
1846 bool SuperWord::implemented(Node_List* p) {
1847   bool retValue = false;
1848   Node* p0 = p->at(0);
1849   if (p0 != NULL) {
1850     int opc = p0->Opcode();
1851     uint size = p->size();
1852     if (p0->is_reduction()) {
1853       const Type *arith_type = p0->bottom_type();
1854       // Length 2 reductions of INT/LONG do not offer performance benefits
1855       if (((arith_type->basic_type() == T_INT) || (arith_type->basic_type() == T_LONG)) && (size == 2)) {
1856         retValue = false;
1857       } else {
1858         retValue = ReductionNode::implemented(opc, size, arith_type->basic_type());
1859       }
1860     } else {
1861       retValue = VectorNode::implemented(opc, size, velt_basic_type(p0));
1862     }
1863     if (!retValue) {
1864       if (is_cmov_pack(p)) {
1865         NOT_PRODUCT(if(is_trace_cmov()) {tty->print_cr("SWPointer::implemented: found cmpd pack"); print_pack(p);})
1866         return true;
1867       }
1868     }
1869   }
1870   return retValue;
1871 }
1872 
1873 bool SuperWord::is_cmov_pack(Node_List* p) {
1874   return _cmovev_kit.pack(p->at(0)) != NULL;
1875 }
1876 //------------------------------same_inputs--------------------------
1877 // For pack p, are all idx operands the same?
1878 bool SuperWord::same_inputs(Node_List* p, int idx) {
1879   Node* p0 = p->at(0);
1880   uint vlen = p->size();
1881   Node* p0_def = p0->in(idx);
1882   for (uint i = 1; i < vlen; i++) {
1883     Node* pi = p->at(i);
1884     Node* pi_def = pi->in(idx);
1885     if (p0_def != pi_def) {
1886       return false;
1887     }
1888   }
1889   return true;
1890 }
1891 
1892 //------------------------------profitable---------------------------
1893 // For pack p, are all operands and all uses (with in the block) vector?
1894 bool SuperWord::profitable(Node_List* p) {
1895   Node* p0 = p->at(0);
1896   uint start, end;
1897   VectorNode::vector_operands(p0, &start, &end);
1898 
1899   // Return false if some inputs are not vectors or vectors with different
1900   // size or alignment.
1901   // Also, for now, return false if not scalar promotion case when inputs are
1902   // the same. Later, implement PackNode and allow differing, non-vector inputs
1903   // (maybe just the ones from outside the block.)
1904   for (uint i = start; i < end; i++) {
1905     if (!is_vector_use(p0, i)) {
1906       return false;
1907     }
1908   }
1909   // Check if reductions are connected
1910   if (p0->is_reduction()) {
1911     Node* second_in = p0->in(2);
1912     Node_List* second_pk = my_pack(second_in);
1913     if ((second_pk == NULL) || (_num_work_vecs == _num_reductions)) {
1914       // Remove reduction flag if no parent pack or if not enough work
1915       // to cover reduction expansion overhead
1916       p0->remove_flag(Node::Flag_is_reduction);
1917       return false;
1918     } else if (second_pk->size() != p->size()) {
1919       return false;
1920     }
1921   }
1922   if (VectorNode::is_shift(p0)) {
1923     // For now, return false if shift count is vector or not scalar promotion
1924     // case (different shift counts) because it is not supported yet.
1925     Node* cnt = p0->in(2);
1926     Node_List* cnt_pk = my_pack(cnt);
1927     if (cnt_pk != NULL)
1928       return false;
1929     if (!same_inputs(p, 2))
1930       return false;
1931   }
1932   if (!p0->is_Store()) {
1933     // For now, return false if not all uses are vector.
1934     // Later, implement ExtractNode and allow non-vector uses (maybe
1935     // just the ones outside the block.)
1936     for (uint i = 0; i < p->size(); i++) {
1937       Node* def = p->at(i);
1938       if (is_cmov_pack_internal_node(p, def)) {
1939         continue;
1940       }
1941       for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
1942         Node* use = def->fast_out(j);
1943         for (uint k = 0; k < use->req(); k++) {
1944           Node* n = use->in(k);
1945           if (def == n) {
1946             // reductions can be loop carried dependences
1947             if (def->is_reduction() && use->is_Phi())
1948               continue;
1949             if (!is_vector_use(use, k)) {
1950               return false;
1951             }
1952           }
1953         }
1954       }
1955     }
1956   }
1957   return true;
1958 }
1959 
1960 //------------------------------schedule---------------------------
1961 // Adjust the memory graph for the packed operations
1962 void SuperWord::schedule() {
1963 
1964   // Co-locate in the memory graph the members of each memory pack
1965   for (int i = 0; i < _packset.length(); i++) {
1966     co_locate_pack(_packset.at(i));
1967   }
1968 }
1969 
1970 //-------------------------------remove_and_insert-------------------
1971 // Remove "current" from its current position in the memory graph and insert
1972 // it after the appropriate insertion point (lip or uip).
1973 void SuperWord::remove_and_insert(MemNode *current, MemNode *prev, MemNode *lip,
1974                                   Node *uip, Unique_Node_List &sched_before) {
1975   Node* my_mem = current->in(MemNode::Memory);
1976   bool sched_up = sched_before.member(current);
1977 
1978   // remove current_store from its current position in the memmory graph
1979   for (DUIterator i = current->outs(); current->has_out(i); i++) {
1980     Node* use = current->out(i);
1981     if (use->is_Mem()) {
1982       assert(use->in(MemNode::Memory) == current, "must be");
1983       if (use == prev) { // connect prev to my_mem
1984           _igvn.replace_input_of(use, MemNode::Memory, my_mem);
1985           --i; //deleted this edge; rescan position
1986       } else if (sched_before.member(use)) {
1987         if (!sched_up) { // Will be moved together with current
1988           _igvn.replace_input_of(use, MemNode::Memory, uip);
1989           --i; //deleted this edge; rescan position
1990         }
1991       } else {
1992         if (sched_up) { // Will be moved together with current
1993           _igvn.replace_input_of(use, MemNode::Memory, lip);
1994           --i; //deleted this edge; rescan position
1995         }
1996       }
1997     }
1998   }
1999 
2000   Node *insert_pt =  sched_up ?  uip : lip;
2001 
2002   // all uses of insert_pt's memory state should use current's instead
2003   for (DUIterator i = insert_pt->outs(); insert_pt->has_out(i); i++) {
2004     Node* use = insert_pt->out(i);
2005     if (use->is_Mem()) {
2006       assert(use->in(MemNode::Memory) == insert_pt, "must be");
2007       _igvn.replace_input_of(use, MemNode::Memory, current);
2008       --i; //deleted this edge; rescan position
2009     } else if (!sched_up && use->is_Phi() && use->bottom_type() == Type::MEMORY) {
2010       uint pos; //lip (lower insert point) must be the last one in the memory slice
2011       for (pos=1; pos < use->req(); pos++) {
2012         if (use->in(pos) == insert_pt) break;
2013       }
2014       _igvn.replace_input_of(use, pos, current);
2015       --i;
2016     }
2017   }
2018 
2019   //connect current to insert_pt
2020   _igvn.replace_input_of(current, MemNode::Memory, insert_pt);
2021 }
2022 
2023 //------------------------------co_locate_pack----------------------------------
2024 // To schedule a store pack, we need to move any sandwiched memory ops either before
2025 // or after the pack, based upon dependence information:
2026 // (1) If any store in the pack depends on the sandwiched memory op, the
2027 //     sandwiched memory op must be scheduled BEFORE the pack;
2028 // (2) If a sandwiched memory op depends on any store in the pack, the
2029 //     sandwiched memory op must be scheduled AFTER the pack;
2030 // (3) If a sandwiched memory op (say, memA) depends on another sandwiched
2031 //     memory op (say memB), memB must be scheduled before memA. So, if memA is
2032 //     scheduled before the pack, memB must also be scheduled before the pack;
2033 // (4) If there is no dependence restriction for a sandwiched memory op, we simply
2034 //     schedule this store AFTER the pack
2035 // (5) We know there is no dependence cycle, so there in no other case;
2036 // (6) Finally, all memory ops in another single pack should be moved in the same direction.
2037 //
2038 // To schedule a load pack, we use the memory state of either the first or the last load in
2039 // the pack, based on the dependence constraint.
2040 void SuperWord::co_locate_pack(Node_List* pk) {
2041   if (pk->at(0)->is_Store()) {
2042     MemNode* first     = executed_first(pk)->as_Mem();
2043     MemNode* last      = executed_last(pk)->as_Mem();
2044     Unique_Node_List schedule_before_pack;
2045     Unique_Node_List memops;
2046 
2047     MemNode* current   = last->in(MemNode::Memory)->as_Mem();
2048     MemNode* previous  = last;
2049     while (true) {
2050       assert(in_bb(current), "stay in block");
2051       memops.push(previous);
2052       for (DUIterator i = current->outs(); current->has_out(i); i++) {
2053         Node* use = current->out(i);
2054         if (use->is_Mem() && use != previous)
2055           memops.push(use);
2056       }
2057       if (current == first) break;
2058       previous = current;
2059       current  = current->in(MemNode::Memory)->as_Mem();
2060     }
2061 
2062     // determine which memory operations should be scheduled before the pack
2063     for (uint i = 1; i < memops.size(); i++) {
2064       Node *s1 = memops.at(i);
2065       if (!in_pack(s1, pk) && !schedule_before_pack.member(s1)) {
2066         for (uint j = 0; j< i; j++) {
2067           Node *s2 = memops.at(j);
2068           if (!independent(s1, s2)) {
2069             if (in_pack(s2, pk) || schedule_before_pack.member(s2)) {
2070               schedule_before_pack.push(s1); // s1 must be scheduled before
2071               Node_List* mem_pk = my_pack(s1);
2072               if (mem_pk != NULL) {
2073                 for (uint ii = 0; ii < mem_pk->size(); ii++) {
2074                   Node* s = mem_pk->at(ii);  // follow partner
2075                   if (memops.member(s) && !schedule_before_pack.member(s))
2076                     schedule_before_pack.push(s);
2077                 }
2078               }
2079               break;
2080             }
2081           }
2082         }
2083       }
2084     }
2085 
2086     Node*    upper_insert_pt = first->in(MemNode::Memory);
2087     // Following code moves loads connected to upper_insert_pt below aliased stores.
2088     // Collect such loads here and reconnect them back to upper_insert_pt later.
2089     memops.clear();
2090     for (DUIterator i = upper_insert_pt->outs(); upper_insert_pt->has_out(i); i++) {
2091       Node* use = upper_insert_pt->out(i);
2092       if (use->is_Mem() && !use->is_Store()) {
2093         memops.push(use);
2094       }
2095     }
2096 
2097     MemNode* lower_insert_pt = last;
2098     previous                 = last; //previous store in pk
2099     current                  = last->in(MemNode::Memory)->as_Mem();
2100 
2101     // start scheduling from "last" to "first"
2102     while (true) {
2103       assert(in_bb(current), "stay in block");
2104       assert(in_pack(previous, pk), "previous stays in pack");
2105       Node* my_mem = current->in(MemNode::Memory);
2106 
2107       if (in_pack(current, pk)) {
2108         // Forward users of my memory state (except "previous) to my input memory state
2109         for (DUIterator i = current->outs(); current->has_out(i); i++) {
2110           Node* use = current->out(i);
2111           if (use->is_Mem() && use != previous) {
2112             assert(use->in(MemNode::Memory) == current, "must be");
2113             if (schedule_before_pack.member(use)) {
2114               _igvn.replace_input_of(use, MemNode::Memory, upper_insert_pt);
2115             } else {
2116               _igvn.replace_input_of(use, MemNode::Memory, lower_insert_pt);
2117             }
2118             --i; // deleted this edge; rescan position
2119           }
2120         }
2121         previous = current;
2122       } else { // !in_pack(current, pk) ==> a sandwiched store
2123         remove_and_insert(current, previous, lower_insert_pt, upper_insert_pt, schedule_before_pack);
2124       }
2125 
2126       if (current == first) break;
2127       current = my_mem->as_Mem();
2128     } // end while
2129 
2130     // Reconnect loads back to upper_insert_pt.
2131     for (uint i = 0; i < memops.size(); i++) {
2132       Node *ld = memops.at(i);
2133       if (ld->in(MemNode::Memory) != upper_insert_pt) {
2134         _igvn.replace_input_of(ld, MemNode::Memory, upper_insert_pt);
2135       }
2136     }
2137   } else if (pk->at(0)->is_Load()) { //load
2138     // all loads in the pack should have the same memory state. By default,
2139     // we use the memory state of the last load. However, if any load could
2140     // not be moved down due to the dependence constraint, we use the memory
2141     // state of the first load.
2142 
2143     // We first need to find the "first" and "last" loads. Start with
2144     // arbitrary values:
2145     Node* last_mem  = pk->at(0)->in(MemNode::Memory);
2146     Node* first_mem = last_mem;
2147     // Walk the memory graph from the current first load until the
2148     // start of the loop and check if nodes on the way are memory
2149     // edges of loads in the pack. The last one we encounter is the
2150     // first load.
2151     for (Node* current = first_mem; in_bb(current); current = current->is_Phi() ? current->in(LoopNode::EntryControl) : current->in(MemNode::Memory)) {
2152       assert(current->is_Mem() || (current->is_Phi() && current->in(0) == bb()), "unexpected memory");
2153       for (uint i = 1; i < pk->size(); i++) {
2154         Node* ld = pk->at(i);
2155         if (ld->in(MemNode::Memory) == current) {
2156           first_mem = current;
2157           break;
2158         }
2159       }
2160     }
2161     // Find the last load by going over the pack again, and walking
2162     // the memory graph from the loads of the pack to the memory of
2163     // the first load. If we encounter the memory of the current last
2164     // load, then we started from further down in the memory graph and
2165     // the load we started from is the last load. Check for dependence
2166     // constraints in that loop as well.
2167     bool schedule_last = true;
2168     for (uint i = 0; i < pk->size(); i++) {
2169       Node* ld = pk->at(i);
2170       for (Node* current = ld->in(MemNode::Memory); current != first_mem; current = current->in(MemNode::Memory)) {
2171         assert(current->is_Mem() && in_bb(current), "unexpected memory");
2172         if (current->in(MemNode::Memory) == last_mem) {
2173           last_mem = ld->in(MemNode::Memory);
2174         }
2175         if (!independent(current, ld)) {
2176           schedule_last = false; // a later store depends on this load
2177         }
2178       }
2179     }
2180 
2181     Node* mem_input = schedule_last ? last_mem : first_mem;
2182     _igvn.hash_delete(mem_input);
2183     // Give each load the same memory state
2184     for (uint i = 0; i < pk->size(); i++) {
2185       LoadNode* ld = pk->at(i)->as_Load();
2186       _igvn.replace_input_of(ld, MemNode::Memory, mem_input);
2187     }
2188   }
2189 }
2190 
2191 #ifndef PRODUCT
2192 void SuperWord::print_loop(bool whole) {
2193   Node_Stack stack(_arena, _phase->C->unique() >> 2);
2194   Node_List rpo_list;
2195   VectorSet visited(_arena);
2196   visited.set(lpt()->_head->_idx);
2197   _phase->rpo(lpt()->_head, stack, visited, rpo_list);
2198   _phase->dump(lpt(), rpo_list.size(), rpo_list );
2199   if(whole) {
2200     tty->print_cr("\n Whole loop tree");
2201     _phase->dump();
2202     tty->print_cr(" End of whole loop tree\n");
2203   }
2204 }
2205 #endif
2206 
2207 //------------------------------output---------------------------
2208 // Convert packs into vector node operations
2209 void SuperWord::output() {
2210   CountedLoopNode *cl = lpt()->_head->as_CountedLoop();
2211   Compile* C = _phase->C;
2212   if (_packset.length() == 0) {
2213     if (cl->is_main_loop()) {
2214       // Instigate more unrolling for optimization when vectorization fails.
2215       C->set_major_progress();
2216       cl->set_notpassed_slp();
2217       cl->mark_do_unroll_only();
2218     }
2219     return;
2220   }
2221 
2222 #ifndef PRODUCT
2223   if (TraceLoopOpts) {
2224     tty->print("SuperWord::output    ");
2225     lpt()->dump_head();
2226   }
2227 #endif
2228 
2229   if (cl->is_main_loop()) {
2230     // MUST ENSURE main loop's initial value is properly aligned:
2231     //  (iv_initial_value + min_iv_offset) % vector_width_in_bytes() == 0
2232 
2233     align_initial_loop_index(align_to_ref());
2234 
2235     // Insert extract (unpack) operations for scalar uses
2236     for (int i = 0; i < _packset.length(); i++) {
2237       insert_extracts(_packset.at(i));
2238     }
2239   }
2240 
2241   uint max_vlen_in_bytes = 0;
2242   uint max_vlen = 0;
2243   bool can_process_post_loop = (PostLoopMultiversioning && Matcher::has_predicated_vectors() && cl->is_post_loop());
2244 
2245   NOT_PRODUCT(if(is_trace_loop_reverse()) {tty->print_cr("SWPointer::output: print loop before create_reserve_version_of_loop"); print_loop(true);})
2246 
2247   CountedLoopReserveKit make_reversable(_phase, _lpt, do_reserve_copy());
2248 
2249   NOT_PRODUCT(if(is_trace_loop_reverse()) {tty->print_cr("SWPointer::output: print loop after create_reserve_version_of_loop"); print_loop(true);})
2250 
2251   if (do_reserve_copy() && !make_reversable.has_reserved()) {
2252     NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: loop was not reserved correctly, exiting SuperWord");})
2253     return;
2254   }
2255 
2256   for (int i = 0; i < _block.length(); i++) {
2257     Node* n = _block.at(i);
2258     Node_List* p = my_pack(n);
2259     if (p && n == executed_last(p)) {
2260       uint vlen = p->size();
2261       uint vlen_in_bytes = 0;
2262       Node* vn = NULL;
2263       Node* low_adr = p->at(0);
2264       Node* first   = executed_first(p);
2265       if (can_process_post_loop) {
2266         // override vlen with the main loops vector length
2267         vlen = cl->slp_max_unroll();
2268       }
2269       NOT_PRODUCT(if(is_trace_cmov()) {tty->print_cr("SWPointer::output: %d executed first, %d executed last in pack", first->_idx, n->_idx); print_pack(p);})
2270       int   opc = n->Opcode();
2271       if (n->is_Load()) {
2272         Node* ctl = n->in(MemNode::Control);
2273         Node* mem = first->in(MemNode::Memory);
2274         SWPointer p1(n->as_Mem(), this, NULL, false);
2275         // Identify the memory dependency for the new loadVector node by
2276         // walking up through memory chain.
2277         // This is done to give flexibility to the new loadVector node so that
2278         // it can move above independent storeVector nodes.
2279         while (mem->is_StoreVector()) {
2280           SWPointer p2(mem->as_Mem(), this, NULL, false);
2281           int cmp = p1.cmp(p2);
2282           if (SWPointer::not_equal(cmp) || !SWPointer::comparable(cmp)) {
2283             mem = mem->in(MemNode::Memory);
2284           } else {
2285             break; // dependent memory
2286           }
2287         }
2288         Node* adr = low_adr->in(MemNode::Address);
2289         const TypePtr* atyp = n->adr_type();
2290         vn = LoadVectorNode::make(opc, ctl, mem, adr, atyp, vlen, velt_basic_type(n), control_dependency(p));
2291         vlen_in_bytes = vn->as_LoadVector()->memory_size();
2292       } else if (n->is_Store()) {
2293         // Promote value to be stored to vector
2294         Node* val = vector_opd(p, MemNode::ValueIn);
2295         if (val == NULL) {
2296           if (do_reserve_copy()) {
2297             NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: val should not be NULL, exiting SuperWord");})
2298             return; //and reverse to backup IG
2299           }
2300           ShouldNotReachHere();
2301         }
2302 
2303         Node* ctl = n->in(MemNode::Control);
2304         Node* mem = first->in(MemNode::Memory);
2305         Node* adr = low_adr->in(MemNode::Address);
2306         const TypePtr* atyp = n->adr_type();
2307         vn = StoreVectorNode::make(opc, ctl, mem, adr, atyp, val, vlen);
2308         vlen_in_bytes = vn->as_StoreVector()->memory_size();
2309       } else if (n->req() == 3 && !is_cmov_pack(p)) {
2310         // Promote operands to vector
2311         Node* in1 = NULL;
2312         bool node_isa_reduction = n->is_reduction();
2313         if (node_isa_reduction) {
2314           // the input to the first reduction operation is retained
2315           in1 = low_adr->in(1);
2316         } else {
2317           in1 = vector_opd(p, 1);
2318           if (in1 == NULL) {
2319             if (do_reserve_copy()) {
2320               NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: in1 should not be NULL, exiting SuperWord");})
2321               return; //and reverse to backup IG
2322             }
2323             ShouldNotReachHere();
2324           }
2325         }
2326         Node* in2 = vector_opd(p, 2);
2327         if (in2 == NULL) {
2328           if (do_reserve_copy()) {
2329             NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: in2 should not be NULL, exiting SuperWord");})
2330             return; //and reverse to backup IG
2331           }
2332           ShouldNotReachHere();
2333         }
2334         if (VectorNode::is_invariant_vector(in1) && (node_isa_reduction == false) && (n->is_Add() || n->is_Mul())) {
2335           // Move invariant vector input into second position to avoid register spilling.
2336           Node* tmp = in1;
2337           in1 = in2;
2338           in2 = tmp;
2339         }
2340         if (node_isa_reduction) {
2341           const Type *arith_type = n->bottom_type();
2342           vn = ReductionNode::make(opc, NULL, in1, in2, arith_type->basic_type());
2343           if (in2->is_Load()) {
2344             vlen_in_bytes = in2->as_LoadVector()->memory_size();
2345           } else {
2346             vlen_in_bytes = in2->as_Vector()->length_in_bytes();
2347           }
2348         } else {
2349           vn = VectorNode::make(opc, in1, in2, vlen, velt_basic_type(n));
2350           vlen_in_bytes = vn->as_Vector()->length_in_bytes();
2351         }
2352       } else if (opc == Op_SqrtF || opc == Op_SqrtD ||
2353                  opc == Op_AbsF || opc == Op_AbsD ||
2354                  opc == Op_NegF || opc == Op_NegD ||
2355                  opc == Op_PopCountI) {
2356         assert(n->req() == 2, "only one input expected");
2357         Node* in = vector_opd(p, 1);
2358         vn = VectorNode::make(opc, in, NULL, vlen, velt_basic_type(n));
2359         vlen_in_bytes = vn->as_Vector()->length_in_bytes();
2360       } else if (is_cmov_pack(p)) {
2361         if (can_process_post_loop) {
2362           // do not refactor of flow in post loop context
2363           return;
2364         }
2365         if (!n->is_CMove()) {
2366           continue;
2367         }
2368         // place here CMoveVDNode
2369         NOT_PRODUCT(if(is_trace_cmov()) {tty->print_cr("SWPointer::output: print before CMove vectorization"); print_loop(false);})
2370         Node* bol = n->in(CMoveNode::Condition);
2371         if (!bol->is_Bool() && bol->Opcode() == Op_ExtractI && bol->req() > 1 ) {
2372           NOT_PRODUCT(if(is_trace_cmov()) {tty->print_cr("SWPointer::output: %d is not Bool node, trying its in(1) node %d", bol->_idx, bol->in(1)->_idx); bol->dump(); bol->in(1)->dump();})
2373           bol = bol->in(1); //may be ExtractNode
2374         }
2375 
2376         assert(bol->is_Bool(), "should be BoolNode - too late to bail out!");
2377         if (!bol->is_Bool()) {
2378           if (do_reserve_copy()) {
2379             NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: expected %d bool node, exiting SuperWord", bol->_idx); bol->dump();})
2380             return; //and reverse to backup IG
2381           }
2382           ShouldNotReachHere();
2383         }
2384 
2385         int cond = (int)bol->as_Bool()->_test._test;
2386         Node* in_cc  = _igvn.intcon(cond);
2387         NOT_PRODUCT(if(is_trace_cmov()) {tty->print("SWPointer::output: created intcon in_cc node %d", in_cc->_idx); in_cc->dump();})
2388         Node* cc = bol->clone();
2389         cc->set_req(1, in_cc);
2390         NOT_PRODUCT(if(is_trace_cmov()) {tty->print("SWPointer::output: created bool cc node %d", cc->_idx); cc->dump();})
2391 
2392         Node* src1 = vector_opd(p, 2); //2=CMoveNode::IfFalse
2393         if (src1 == NULL) {
2394           if (do_reserve_copy()) {
2395             NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: src1 should not be NULL, exiting SuperWord");})
2396             return; //and reverse to backup IG
2397           }
2398           ShouldNotReachHere();
2399         }
2400         Node* src2 = vector_opd(p, 3); //3=CMoveNode::IfTrue
2401         if (src2 == NULL) {
2402           if (do_reserve_copy()) {
2403             NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: src2 should not be NULL, exiting SuperWord");})
2404             return; //and reverse to backup IG
2405           }
2406           ShouldNotReachHere();
2407         }
2408         BasicType bt = velt_basic_type(n);
2409         const TypeVect* vt = TypeVect::make(bt, vlen);
2410         assert(bt == T_FLOAT || bt == T_DOUBLE, "Only vectorization for FP cmovs is supported");
2411         if (bt == T_FLOAT) {
2412           vn = new CMoveVFNode(cc, src1, src2, vt);
2413         } else {
2414           assert(bt == T_DOUBLE, "Expected double");
2415           vn = new CMoveVDNode(cc, src1, src2, vt);
2416         }
2417         NOT_PRODUCT(if(is_trace_cmov()) {tty->print("SWPointer::output: created new CMove node %d: ", vn->_idx); vn->dump();})
2418       } else if (opc == Op_FmaD || opc == Op_FmaF) {
2419         // Promote operands to vector
2420         Node* in1 = vector_opd(p, 1);
2421         Node* in2 = vector_opd(p, 2);
2422         Node* in3 = vector_opd(p, 3);
2423         vn = VectorNode::make(opc, in1, in2, in3, vlen, velt_basic_type(n));
2424         vlen_in_bytes = vn->as_Vector()->length_in_bytes();
2425       } else {
2426         if (do_reserve_copy()) {
2427           NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: ShouldNotReachHere, exiting SuperWord");})
2428           return; //and reverse to backup IG
2429         }
2430         ShouldNotReachHere();
2431       }
2432 
2433       assert(vn != NULL, "sanity");
2434       if (vn == NULL) {
2435         if (do_reserve_copy()){
2436           NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("SWPointer::output: got NULL node, cannot proceed, exiting SuperWord");})
2437           return; //and reverse to backup IG
2438         }
2439         ShouldNotReachHere();
2440       }
2441 
2442       _block.at_put(i, vn);
2443       _igvn.register_new_node_with_optimizer(vn);
2444       _phase->set_ctrl(vn, _phase->get_ctrl(p->at(0)));
2445       for (uint j = 0; j < p->size(); j++) {
2446         Node* pm = p->at(j);
2447         _igvn.replace_node(pm, vn);
2448       }
2449       _igvn._worklist.push(vn);
2450 
2451       if (can_process_post_loop) {
2452         // first check if the vector size if the maximum vector which we can use on the machine,
2453         // other vector size have reduced values for predicated data mapping.
2454         if (vlen_in_bytes != (uint)MaxVectorSize) {
2455           return;
2456         }
2457       }
2458 
2459       if (vlen_in_bytes >= max_vlen_in_bytes && vlen > max_vlen) {
2460         max_vlen = vlen;
2461         max_vlen_in_bytes = vlen_in_bytes;
2462       }
2463 #ifdef ASSERT
2464       if (TraceNewVectors) {
2465         tty->print("new Vector node: ");
2466         vn->dump();
2467       }
2468 #endif
2469     }
2470   }//for (int i = 0; i < _block.length(); i++)
2471 
2472   if (max_vlen_in_bytes > C->max_vector_size()) {
2473     C->set_max_vector_size(max_vlen_in_bytes);
2474   }
2475   if (max_vlen_in_bytes > 0) {
2476     cl->mark_loop_vectorized();
2477   }
2478 
2479   if (SuperWordLoopUnrollAnalysis) {
2480     if (cl->has_passed_slp()) {
2481       uint slp_max_unroll_factor = cl->slp_max_unroll();
2482       if (slp_max_unroll_factor == max_vlen) {
2483         if (TraceSuperWordLoopUnrollAnalysis) {
2484           tty->print_cr("vector loop(unroll=%d, len=%d)\n", max_vlen, max_vlen_in_bytes*BitsPerByte);
2485         }
2486 
2487         // For atomic unrolled loops which are vector mapped, instigate more unrolling
2488         cl->set_notpassed_slp();
2489         if (cl->is_main_loop()) {
2490           // if vector resources are limited, do not allow additional unrolling, also
2491           // do not unroll more on pure vector loops which were not reduced so that we can
2492           // program the post loop to single iteration execution.
2493           if (FLOATPRESSURE > 8) {
2494             C->set_major_progress();
2495             cl->mark_do_unroll_only();
2496           }
2497         }
2498 
2499         if (do_reserve_copy()) {
2500           if (can_process_post_loop) {
2501             // Now create the difference of trip and limit and use it as our mask index.
2502             // Note: We limited the unroll of the vectorized loop so that
2503             //       only vlen-1 size iterations can remain to be mask programmed.
2504             Node *incr = cl->incr();
2505             SubINode *index = new SubINode(cl->limit(), cl->init_trip());
2506             _igvn.register_new_node_with_optimizer(index);
2507             SetVectMaskINode  *mask = new SetVectMaskINode(_phase->get_ctrl(cl->init_trip()), index);
2508             _igvn.register_new_node_with_optimizer(mask);
2509             // make this a single iteration loop
2510             AddINode *new_incr = new AddINode(incr->in(1), mask);
2511             _igvn.register_new_node_with_optimizer(new_incr);
2512             _phase->set_ctrl(new_incr, _phase->get_ctrl(incr));
2513             _igvn.replace_node(incr, new_incr);
2514             cl->mark_is_multiversioned();
2515             cl->loopexit()->add_flag(Node::Flag_has_vector_mask_set);
2516           }
2517         }
2518       }
2519     }
2520   }
2521 
2522   if (do_reserve_copy()) {
2523     make_reversable.use_new();
2524   }
2525   NOT_PRODUCT(if(is_trace_loop_reverse()) {tty->print_cr("\n Final loop after SuperWord"); print_loop(true);})
2526   return;
2527 }
2528 
2529 //------------------------------vector_opd---------------------------
2530 // Create a vector operand for the nodes in pack p for operand: in(opd_idx)
2531 Node* SuperWord::vector_opd(Node_List* p, int opd_idx) {
2532   Node* p0 = p->at(0);
2533   uint vlen = p->size();
2534   Node* opd = p0->in(opd_idx);
2535   CountedLoopNode *cl = lpt()->_head->as_CountedLoop();
2536 
2537   if (PostLoopMultiversioning && Matcher::has_predicated_vectors() && cl->is_post_loop()) {
2538     // override vlen with the main loops vector length
2539     vlen = cl->slp_max_unroll();
2540   }
2541 
2542   if (same_inputs(p, opd_idx)) {
2543     if (opd->is_Vector() || opd->is_LoadVector()) {
2544       assert(((opd_idx != 2) || !VectorNode::is_shift(p0)), "shift's count can't be vector");
2545       if (opd_idx == 2 && VectorNode::is_shift(p0)) {
2546         NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("shift's count can't be vector");})
2547         return NULL;
2548       }
2549       return opd; // input is matching vector
2550     }
2551     if ((opd_idx == 2) && VectorNode::is_shift(p0)) {
2552       Compile* C = _phase->C;
2553       Node* cnt = opd;
2554       // Vector instructions do not mask shift count, do it here.
2555       juint mask = (p0->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
2556       const TypeInt* t = opd->find_int_type();
2557       if (t != NULL && t->is_con()) {
2558         juint shift = t->get_con();
2559         if (shift > mask) { // Unsigned cmp
2560           cnt = ConNode::make(TypeInt::make(shift & mask));
2561         }
2562       } else {
2563         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
2564           cnt = ConNode::make(TypeInt::make(mask));
2565           _igvn.register_new_node_with_optimizer(cnt);
2566           cnt = new AndINode(opd, cnt);
2567           _igvn.register_new_node_with_optimizer(cnt);
2568           _phase->set_ctrl(cnt, _phase->get_ctrl(opd));
2569         }
2570         assert(opd->bottom_type()->isa_int(), "int type only");
2571         if (!opd->bottom_type()->isa_int()) {
2572           NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("Should be int type only");})
2573           return NULL;
2574         }
2575         // Move non constant shift count into vector register.
2576         cnt = VectorNode::shift_count(p0, cnt, vlen, velt_basic_type(p0));
2577       }
2578       if (cnt != opd) {
2579         _igvn.register_new_node_with_optimizer(cnt);
2580         _phase->set_ctrl(cnt, _phase->get_ctrl(opd));
2581       }
2582       return cnt;
2583     }
2584     assert(!opd->is_StoreVector(), "such vector is not expected here");
2585     if (opd->is_StoreVector()) {
2586       NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("StoreVector is not expected here");})
2587       return NULL;
2588     }
2589     // Convert scalar input to vector with the same number of elements as
2590     // p0's vector. Use p0's type because size of operand's container in
2591     // vector should match p0's size regardless operand's size.
2592     const Type* p0_t = velt_type(p0);
2593     VectorNode* vn = VectorNode::scalar2vector(opd, vlen, p0_t);
2594 
2595     _igvn.register_new_node_with_optimizer(vn);
2596     _phase->set_ctrl(vn, _phase->get_ctrl(opd));
2597 #ifdef ASSERT
2598     if (TraceNewVectors) {
2599       tty->print("new Vector node: ");
2600       vn->dump();
2601     }
2602 #endif
2603     return vn;
2604   }
2605 
2606   // Insert pack operation
2607   BasicType bt = velt_basic_type(p0);
2608   PackNode* pk = PackNode::make(opd, vlen, bt);
2609   DEBUG_ONLY( const BasicType opd_bt = opd->bottom_type()->basic_type(); )
2610 
2611   for (uint i = 1; i < vlen; i++) {
2612     Node* pi = p->at(i);
2613     Node* in = pi->in(opd_idx);
2614     assert(my_pack(in) == NULL, "Should already have been unpacked");
2615     if (my_pack(in) != NULL) {
2616       NOT_PRODUCT(if(is_trace_loop_reverse() || TraceLoopOpts) {tty->print_cr("Should already have been unpacked");})
2617       return NULL;
2618     }
2619     assert(opd_bt == in->bottom_type()->basic_type(), "all same type");
2620     pk->add_opd(in);
2621   }
2622   _igvn.register_new_node_with_optimizer(pk);
2623   _phase->set_ctrl(pk, _phase->get_ctrl(opd));
2624 #ifdef ASSERT
2625   if (TraceNewVectors) {
2626     tty->print("new Vector node: ");
2627     pk->dump();
2628   }
2629 #endif
2630   return pk;
2631 }
2632 
2633 //------------------------------insert_extracts---------------------------
2634 // If a use of pack p is not a vector use, then replace the
2635 // use with an extract operation.
2636 void SuperWord::insert_extracts(Node_List* p) {
2637   if (p->at(0)->is_Store()) return;
2638   assert(_n_idx_list.is_empty(), "empty (node,index) list");
2639 
2640   // Inspect each use of each pack member.  For each use that is
2641   // not a vector use, replace the use with an extract operation.
2642 
2643   for (uint i = 0; i < p->size(); i++) {
2644     Node* def = p->at(i);
2645     for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
2646       Node* use = def->fast_out(j);
2647       for (uint k = 0; k < use->req(); k++) {
2648         Node* n = use->in(k);
2649         if (def == n) {
2650           Node_List* u_pk = my_pack(use);
2651           if ((u_pk == NULL || !is_cmov_pack(u_pk) || use->is_CMove()) && !is_vector_use(use, k)) {
2652               _n_idx_list.push(use, k);
2653           }
2654         }
2655       }
2656     }
2657   }
2658 
2659   while (_n_idx_list.is_nonempty()) {
2660     Node* use = _n_idx_list.node();
2661     int   idx = _n_idx_list.index();
2662     _n_idx_list.pop();
2663     Node* def = use->in(idx);
2664 
2665     if (def->is_reduction()) continue;
2666 
2667     // Insert extract operation
2668     _igvn.hash_delete(def);
2669     int def_pos = alignment(def) / data_size(def);
2670 
2671     Node* ex = ExtractNode::make(def, def_pos, velt_basic_type(def));
2672     _igvn.register_new_node_with_optimizer(ex);
2673     _phase->set_ctrl(ex, _phase->get_ctrl(def));
2674     _igvn.replace_input_of(use, idx, ex);
2675     _igvn._worklist.push(def);
2676 
2677     bb_insert_after(ex, bb_idx(def));
2678     set_velt_type(ex, velt_type(def));
2679   }
2680 }
2681 
2682 //------------------------------is_vector_use---------------------------
2683 // Is use->in(u_idx) a vector use?
2684 bool SuperWord::is_vector_use(Node* use, int u_idx) {
2685   Node_List* u_pk = my_pack(use);
2686   if (u_pk == NULL) return false;
2687   if (use->is_reduction()) return true;
2688   Node* def = use->in(u_idx);
2689   Node_List* d_pk = my_pack(def);
2690   if (d_pk == NULL) {
2691     // check for scalar promotion
2692     Node* n = u_pk->at(0)->in(u_idx);
2693     for (uint i = 1; i < u_pk->size(); i++) {
2694       if (u_pk->at(i)->in(u_idx) != n) return false;
2695     }
2696     return true;
2697   }
2698   if (u_pk->size() != d_pk->size())
2699     return false;
2700   for (uint i = 0; i < u_pk->size(); i++) {
2701     Node* ui = u_pk->at(i);
2702     Node* di = d_pk->at(i);
2703     if (ui->in(u_idx) != di || alignment(ui) != alignment(di))
2704       return false;
2705   }
2706   return true;
2707 }
2708 
2709 //------------------------------construct_bb---------------------------
2710 // Construct reverse postorder list of block members
2711 bool SuperWord::construct_bb() {
2712   Node* entry = bb();
2713 
2714   assert(_stk.length() == 0,            "stk is empty");
2715   assert(_block.length() == 0,          "block is empty");
2716   assert(_data_entry.length() == 0,     "data_entry is empty");
2717   assert(_mem_slice_head.length() == 0, "mem_slice_head is empty");
2718   assert(_mem_slice_tail.length() == 0, "mem_slice_tail is empty");
2719 
2720   // Find non-control nodes with no inputs from within block,
2721   // create a temporary map from node _idx to bb_idx for use
2722   // by the visited and post_visited sets,
2723   // and count number of nodes in block.
2724   int bb_ct = 0;
2725   for (uint i = 0; i < lpt()->_body.size(); i++) {
2726     Node *n = lpt()->_body.at(i);
2727     set_bb_idx(n, i); // Create a temporary map
2728     if (in_bb(n)) {
2729       if (n->is_LoadStore() || n->is_MergeMem() ||
2730           (n->is_Proj() && !n->as_Proj()->is_CFG())) {
2731         // Bailout if the loop has LoadStore, MergeMem or data Proj
2732         // nodes. Superword optimization does not work with them.
2733         return false;
2734       }
2735       bb_ct++;
2736       if (!n->is_CFG()) {
2737         bool found = false;
2738         for (uint j = 0; j < n->req(); j++) {
2739           Node* def = n->in(j);
2740           if (def && in_bb(def)) {
2741             found = true;
2742             break;
2743           }
2744         }
2745         if (!found) {
2746           assert(n != entry, "can't be entry");
2747           _data_entry.push(n);
2748         }
2749       }
2750     }
2751   }
2752 
2753   // Find memory slices (head and tail)
2754   for (DUIterator_Fast imax, i = lp()->fast_outs(imax); i < imax; i++) {
2755     Node *n = lp()->fast_out(i);
2756     if (in_bb(n) && (n->is_Phi() && n->bottom_type() == Type::MEMORY)) {
2757       Node* n_tail  = n->in(LoopNode::LoopBackControl);
2758       if (n_tail != n->in(LoopNode::EntryControl)) {
2759         if (!n_tail->is_Mem()) {
2760           assert(n_tail->is_Mem(), "unexpected node for memory slice: %s", n_tail->Name());
2761           return false; // Bailout
2762         }
2763         _mem_slice_head.push(n);
2764         _mem_slice_tail.push(n_tail);
2765       }
2766     }
2767   }
2768 
2769   // Create an RPO list of nodes in block
2770 
2771   visited_clear();
2772   post_visited_clear();
2773 
2774   // Push all non-control nodes with no inputs from within block, then control entry
2775   for (int j = 0; j < _data_entry.length(); j++) {
2776     Node* n = _data_entry.at(j);
2777     visited_set(n);
2778     _stk.push(n);
2779   }
2780   visited_set(entry);
2781   _stk.push(entry);
2782 
2783   // Do a depth first walk over out edges
2784   int rpo_idx = bb_ct - 1;
2785   int size;
2786   int reduction_uses = 0;
2787   while ((size = _stk.length()) > 0) {
2788     Node* n = _stk.top(); // Leave node on stack
2789     if (!visited_test_set(n)) {
2790       // forward arc in graph
2791     } else if (!post_visited_test(n)) {
2792       // cross or back arc
2793       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2794         Node *use = n->fast_out(i);
2795         if (in_bb(use) && !visited_test(use) &&
2796             // Don't go around backedge
2797             (!use->is_Phi() || n == entry)) {
2798           if (use->is_reduction()) {
2799             // First see if we can map the reduction on the given system we are on, then
2800             // make a data entry operation for each reduction we see.
2801             BasicType bt = use->bottom_type()->basic_type();
2802             if (ReductionNode::implemented(use->Opcode(), Matcher::min_vector_size(bt), bt)) {
2803               reduction_uses++;
2804             }
2805           }
2806           _stk.push(use);
2807         }
2808       }
2809       if (_stk.length() == size) {
2810         // There were no additional uses, post visit node now
2811         _stk.pop(); // Remove node from stack
2812         assert(rpo_idx >= 0, "");
2813         _block.at_put_grow(rpo_idx, n);
2814         rpo_idx--;
2815         post_visited_set(n);
2816         assert(rpo_idx >= 0 || _stk.is_empty(), "");
2817       }
2818     } else {
2819       _stk.pop(); // Remove post-visited node from stack
2820     }
2821   }//while
2822 
2823   int ii_current = -1;
2824   unsigned int load_idx = (unsigned int)-1;
2825   _ii_order.clear();
2826   // Create real map of block indices for nodes
2827   for (int j = 0; j < _block.length(); j++) {
2828     Node* n = _block.at(j);
2829     set_bb_idx(n, j);
2830     if (_do_vector_loop && n->is_Load()) {
2831       if (ii_current == -1) {
2832         ii_current = _clone_map.gen(n->_idx);
2833         _ii_order.push(ii_current);
2834         load_idx = _clone_map.idx(n->_idx);
2835       } else if (_clone_map.idx(n->_idx) == load_idx && _clone_map.gen(n->_idx) != ii_current) {
2836         ii_current = _clone_map.gen(n->_idx);
2837         _ii_order.push(ii_current);
2838       }
2839     }
2840   }//for
2841 
2842   // Ensure extra info is allocated.
2843   initialize_bb();
2844 
2845 #ifndef PRODUCT
2846   if (_vector_loop_debug && _ii_order.length() > 0) {
2847     tty->print("SuperWord::construct_bb: List of generations: ");
2848     for (int jj = 0; jj < _ii_order.length(); ++jj) {
2849       tty->print("  %d:%d", jj, _ii_order.at(jj));
2850     }
2851     tty->print_cr(" ");
2852   }
2853   if (TraceSuperWord) {
2854     print_bb();
2855     tty->print_cr("\ndata entry nodes: %s", _data_entry.length() > 0 ? "" : "NONE");
2856     for (int m = 0; m < _data_entry.length(); m++) {
2857       tty->print("%3d ", m);
2858       _data_entry.at(m)->dump();
2859     }
2860     tty->print_cr("\nmemory slices: %s", _mem_slice_head.length() > 0 ? "" : "NONE");
2861     for (int m = 0; m < _mem_slice_head.length(); m++) {
2862       tty->print("%3d ", m); _mem_slice_head.at(m)->dump();
2863       tty->print("    ");    _mem_slice_tail.at(m)->dump();
2864     }
2865   }
2866 #endif
2867   assert(rpo_idx == -1 && bb_ct == _block.length(), "all block members found");
2868   return (_mem_slice_head.length() > 0) || (reduction_uses > 0) || (_data_entry.length() > 0);
2869 }
2870 
2871 //------------------------------initialize_bb---------------------------
2872 // Initialize per node info
2873 void SuperWord::initialize_bb() {
2874   Node* last = _block.at(_block.length() - 1);
2875   grow_node_info(bb_idx(last));
2876 }
2877 
2878 //------------------------------bb_insert_after---------------------------
2879 // Insert n into block after pos
2880 void SuperWord::bb_insert_after(Node* n, int pos) {
2881   int n_pos = pos + 1;
2882   // Make room
2883   for (int i = _block.length() - 1; i >= n_pos; i--) {
2884     _block.at_put_grow(i+1, _block.at(i));
2885   }
2886   for (int j = _node_info.length() - 1; j >= n_pos; j--) {
2887     _node_info.at_put_grow(j+1, _node_info.at(j));
2888   }
2889   // Set value
2890   _block.at_put_grow(n_pos, n);
2891   _node_info.at_put_grow(n_pos, SWNodeInfo::initial);
2892   // Adjust map from node->_idx to _block index
2893   for (int i = n_pos; i < _block.length(); i++) {
2894     set_bb_idx(_block.at(i), i);
2895   }
2896 }
2897 
2898 //------------------------------compute_max_depth---------------------------
2899 // Compute max depth for expressions from beginning of block
2900 // Use to prune search paths during test for independence.
2901 void SuperWord::compute_max_depth() {
2902   int ct = 0;
2903   bool again;
2904   do {
2905     again = false;
2906     for (int i = 0; i < _block.length(); i++) {
2907       Node* n = _block.at(i);
2908       if (!n->is_Phi()) {
2909         int d_orig = depth(n);
2910         int d_in   = 0;
2911         for (DepPreds preds(n, _dg); !preds.done(); preds.next()) {
2912           Node* pred = preds.current();
2913           if (in_bb(pred)) {
2914             d_in = MAX2(d_in, depth(pred));
2915           }
2916         }
2917         if (d_in + 1 != d_orig) {
2918           set_depth(n, d_in + 1);
2919           again = true;
2920         }
2921       }
2922     }
2923     ct++;
2924   } while (again);
2925 
2926   if (TraceSuperWord && Verbose) {
2927     tty->print_cr("compute_max_depth iterated: %d times", ct);
2928   }
2929 }
2930 
2931 //-------------------------compute_vector_element_type-----------------------
2932 // Compute necessary vector element type for expressions
2933 // This propagates backwards a narrower integer type when the
2934 // upper bits of the value are not needed.
2935 // Example:  char a,b,c;  a = b + c;
2936 // Normally the type of the add is integer, but for packed character
2937 // operations the type of the add needs to be char.
2938 void SuperWord::compute_vector_element_type() {
2939   if (TraceSuperWord && Verbose) {
2940     tty->print_cr("\ncompute_velt_type:");
2941   }
2942 
2943   // Initial type
2944   for (int i = 0; i < _block.length(); i++) {
2945     Node* n = _block.at(i);
2946     set_velt_type(n, container_type(n));
2947   }
2948 
2949   // Propagate integer narrowed type backwards through operations
2950   // that don't depend on higher order bits
2951   for (int i = _block.length() - 1; i >= 0; i--) {
2952     Node* n = _block.at(i);
2953     // Only integer types need be examined
2954     const Type* vtn = velt_type(n);
2955     if (vtn->basic_type() == T_INT) {
2956       uint start, end;
2957       VectorNode::vector_operands(n, &start, &end);
2958 
2959       for (uint j = start; j < end; j++) {
2960         Node* in  = n->in(j);
2961         // Don't propagate through a memory
2962         if (!in->is_Mem() && in_bb(in) && velt_type(in)->basic_type() == T_INT &&
2963             data_size(n) < data_size(in)) {
2964           bool same_type = true;
2965           for (DUIterator_Fast kmax, k = in->fast_outs(kmax); k < kmax; k++) {
2966             Node *use = in->fast_out(k);
2967             if (!in_bb(use) || !same_velt_type(use, n)) {
2968               same_type = false;
2969               break;
2970             }
2971           }
2972           if (same_type) {
2973             // For right shifts of small integer types (bool, byte, char, short)
2974             // we need precise information about sign-ness. Only Load nodes have
2975             // this information because Store nodes are the same for signed and
2976             // unsigned values. And any arithmetic operation after a load may
2977             // expand a value to signed Int so such right shifts can't be used
2978             // because vector elements do not have upper bits of Int.
2979             const Type* vt = vtn;
2980             if (VectorNode::is_shift(in)) {
2981               Node* load = in->in(1);
2982               if (load->is_Load() && in_bb(load) && (velt_type(load)->basic_type() == T_INT)) {
2983                 vt = velt_type(load);
2984               } else if (in->Opcode() != Op_LShiftI) {
2985                 // Widen type to Int to avoid creation of right shift vector
2986                 // (align + data_size(s1) check in stmts_can_pack() will fail).
2987                 // Note, left shifts work regardless type.
2988                 vt = TypeInt::INT;
2989               }
2990             }
2991             set_velt_type(in, vt);
2992           }
2993         }
2994       }
2995     }
2996   }
2997 #ifndef PRODUCT
2998   if (TraceSuperWord && Verbose) {
2999     for (int i = 0; i < _block.length(); i++) {
3000       Node* n = _block.at(i);
3001       velt_type(n)->dump();
3002       tty->print("\t");
3003       n->dump();
3004     }
3005   }
3006 #endif
3007 }
3008 
3009 //------------------------------memory_alignment---------------------------
3010 // Alignment within a vector memory reference
3011 int SuperWord::memory_alignment(MemNode* s, int iv_adjust) {
3012   #ifndef PRODUCT
3013     if(TraceSuperWord && Verbose) {
3014       tty->print("SuperWord::memory_alignment within a vector memory reference for %d:  ", s->_idx); s->dump();
3015     }
3016   #endif
3017   NOT_PRODUCT(SWPointer::Tracer::Depth ddd(0);)
3018   SWPointer p(s, this, NULL, false);
3019   if (!p.valid()) {
3020     NOT_PRODUCT(if(is_trace_alignment()) tty->print("SWPointer::memory_alignment: SWPointer p invalid, return bottom_align");)
3021     return bottom_align;
3022   }
3023   int vw = vector_width_in_bytes(s);
3024   if (vw < 2) {
3025     NOT_PRODUCT(if(is_trace_alignment()) tty->print_cr("SWPointer::memory_alignment: vector_width_in_bytes < 2, return bottom_align");)
3026     return bottom_align; // No vectors for this type
3027   }
3028   int offset  = p.offset_in_bytes();
3029   offset     += iv_adjust*p.memory_size();
3030   int off_rem = offset % vw;
3031   int off_mod = off_rem >= 0 ? off_rem : off_rem + vw;
3032   if (TraceSuperWord && Verbose) {
3033     tty->print_cr("SWPointer::memory_alignment: off_rem = %d, off_mod = %d", off_rem, off_mod);
3034   }
3035   return off_mod;
3036 }
3037 
3038 //---------------------------container_type---------------------------
3039 // Smallest type containing range of values
3040 const Type* SuperWord::container_type(Node* n) {
3041   if (n->is_Mem()) {
3042     BasicType bt = n->as_Mem()->memory_type();
3043     if (n->is_Store() && (bt == T_CHAR)) {
3044       // Use T_SHORT type instead of T_CHAR for stored values because any
3045       // preceding arithmetic operation extends values to signed Int.
3046       bt = T_SHORT;
3047     }
3048     if (n->Opcode() == Op_LoadUB) {
3049       // Adjust type for unsigned byte loads, it is important for right shifts.
3050       // T_BOOLEAN is used because there is no basic type representing type
3051       // TypeInt::UBYTE. Use of T_BOOLEAN for vectors is fine because only
3052       // size (one byte) and sign is important.
3053       bt = T_BOOLEAN;
3054     }
3055     return Type::get_const_basic_type(bt);
3056   }
3057   const Type* t = _igvn.type(n);
3058   if (t->basic_type() == T_INT) {
3059     // A narrow type of arithmetic operations will be determined by
3060     // propagating the type of memory operations.
3061     return TypeInt::INT;
3062   }
3063   return t;
3064 }
3065 
3066 bool SuperWord::same_velt_type(Node* n1, Node* n2) {
3067   const Type* vt1 = velt_type(n1);
3068   const Type* vt2 = velt_type(n2);
3069   if (vt1->basic_type() == T_INT && vt2->basic_type() == T_INT) {
3070     // Compare vectors element sizes for integer types.
3071     return data_size(n1) == data_size(n2);
3072   }
3073   return vt1 == vt2;
3074 }
3075 
3076 //------------------------------in_packset---------------------------
3077 // Are s1 and s2 in a pack pair and ordered as s1,s2?
3078 bool SuperWord::in_packset(Node* s1, Node* s2) {
3079   for (int i = 0; i < _packset.length(); i++) {
3080     Node_List* p = _packset.at(i);
3081     assert(p->size() == 2, "must be");
3082     if (p->at(0) == s1 && p->at(p->size()-1) == s2) {
3083       return true;
3084     }
3085   }
3086   return false;
3087 }
3088 
3089 //------------------------------in_pack---------------------------
3090 // Is s in pack p?
3091 Node_List* SuperWord::in_pack(Node* s, Node_List* p) {
3092   for (uint i = 0; i < p->size(); i++) {
3093     if (p->at(i) == s) {
3094       return p;
3095     }
3096   }
3097   return NULL;
3098 }
3099 
3100 //------------------------------remove_pack_at---------------------------
3101 // Remove the pack at position pos in the packset
3102 void SuperWord::remove_pack_at(int pos) {
3103   Node_List* p = _packset.at(pos);
3104   for (uint i = 0; i < p->size(); i++) {
3105     Node* s = p->at(i);
3106     set_my_pack(s, NULL);
3107   }
3108   _packset.remove_at(pos);
3109 }
3110 
3111 void SuperWord::packset_sort(int n) {
3112   // simple bubble sort so that we capitalize with O(n) when its already sorted
3113   while (n != 0) {
3114     bool swapped = false;
3115     for (int i = 1; i < n; i++) {
3116       Node_List* q_low = _packset.at(i-1);
3117       Node_List* q_i = _packset.at(i);
3118 
3119       // only swap when we find something to swap
3120       if (alignment(q_low->at(0)) > alignment(q_i->at(0))) {
3121         Node_List* t = q_i;
3122         *(_packset.adr_at(i)) = q_low;
3123         *(_packset.adr_at(i-1)) = q_i;
3124         swapped = true;
3125       }
3126     }
3127     if (swapped == false) break;
3128     n--;
3129   }
3130 }
3131 
3132 //------------------------------executed_first---------------------------
3133 // Return the node executed first in pack p.  Uses the RPO block list
3134 // to determine order.
3135 Node* SuperWord::executed_first(Node_List* p) {
3136   Node* n = p->at(0);
3137   int n_rpo = bb_idx(n);
3138   for (uint i = 1; i < p->size(); i++) {
3139     Node* s = p->at(i);
3140     int s_rpo = bb_idx(s);
3141     if (s_rpo < n_rpo) {
3142       n = s;
3143       n_rpo = s_rpo;
3144     }
3145   }
3146   return n;
3147 }
3148 
3149 //------------------------------executed_last---------------------------
3150 // Return the node executed last in pack p.
3151 Node* SuperWord::executed_last(Node_List* p) {
3152   Node* n = p->at(0);
3153   int n_rpo = bb_idx(n);
3154   for (uint i = 1; i < p->size(); i++) {
3155     Node* s = p->at(i);
3156     int s_rpo = bb_idx(s);
3157     if (s_rpo > n_rpo) {
3158       n = s;
3159       n_rpo = s_rpo;
3160     }
3161   }
3162   return n;
3163 }
3164 
3165 LoadNode::ControlDependency SuperWord::control_dependency(Node_List* p) {
3166   LoadNode::ControlDependency dep = LoadNode::DependsOnlyOnTest;
3167   for (uint i = 0; i < p->size(); i++) {
3168     Node* n = p->at(i);
3169     assert(n->is_Load(), "only meaningful for loads");
3170     if (!n->depends_only_on_test()) {
3171       dep = LoadNode::Pinned;
3172     }
3173   }
3174   return dep;
3175 }
3176 
3177 
3178 //----------------------------align_initial_loop_index---------------------------
3179 // Adjust pre-loop limit so that in main loop, a load/store reference
3180 // to align_to_ref will be a position zero in the vector.
3181 //   (iv + k) mod vector_align == 0
3182 void SuperWord::align_initial_loop_index(MemNode* align_to_ref) {
3183   CountedLoopNode *main_head = lp()->as_CountedLoop();
3184   assert(main_head->is_main_loop(), "");
3185   CountedLoopEndNode* pre_end = get_pre_loop_end(main_head);
3186   assert(pre_end != NULL, "we must have a correct pre-loop");
3187   Node *pre_opaq1 = pre_end->limit();
3188   assert(pre_opaq1->Opcode() == Op_Opaque1, "");
3189   Opaque1Node *pre_opaq = (Opaque1Node*)pre_opaq1;
3190   Node *lim0 = pre_opaq->in(1);
3191 
3192   // Where we put new limit calculations
3193   Node *pre_ctrl = pre_end->loopnode()->in(LoopNode::EntryControl);
3194 
3195   // Ensure the original loop limit is available from the
3196   // pre-loop Opaque1 node.
3197   Node *orig_limit = pre_opaq->original_loop_limit();
3198   assert(orig_limit != NULL && _igvn.type(orig_limit) != Type::TOP, "");
3199 
3200   SWPointer align_to_ref_p(align_to_ref, this, NULL, false);
3201   assert(align_to_ref_p.valid(), "sanity");
3202 
3203   // Given:
3204   //     lim0 == original pre loop limit
3205   //     V == v_align (power of 2)
3206   //     invar == extra invariant piece of the address expression
3207   //     e == offset [ +/- invar ]
3208   //
3209   // When reassociating expressions involving '%' the basic rules are:
3210   //     (a - b) % k == 0   =>  a % k == b % k
3211   // and:
3212   //     (a + b) % k == 0   =>  a % k == (k - b) % k
3213   //
3214   // For stride > 0 && scale > 0,
3215   //   Derive the new pre-loop limit "lim" such that the two constraints:
3216   //     (1) lim = lim0 + N           (where N is some positive integer < V)
3217   //     (2) (e + lim) % V == 0
3218   //   are true.
3219   //
3220   //   Substituting (1) into (2),
3221   //     (e + lim0 + N) % V == 0
3222   //   solve for N:
3223   //     N = (V - (e + lim0)) % V
3224   //   substitute back into (1), so that new limit
3225   //     lim = lim0 + (V - (e + lim0)) % V
3226   //
3227   // For stride > 0 && scale < 0
3228   //   Constraints:
3229   //     lim = lim0 + N
3230   //     (e - lim) % V == 0
3231   //   Solving for lim:
3232   //     (e - lim0 - N) % V == 0
3233   //     N = (e - lim0) % V
3234   //     lim = lim0 + (e - lim0) % V
3235   //
3236   // For stride < 0 && scale > 0
3237   //   Constraints:
3238   //     lim = lim0 - N
3239   //     (e + lim) % V == 0
3240   //   Solving for lim:
3241   //     (e + lim0 - N) % V == 0
3242   //     N = (e + lim0) % V
3243   //     lim = lim0 - (e + lim0) % V
3244   //
3245   // For stride < 0 && scale < 0
3246   //   Constraints:
3247   //     lim = lim0 - N
3248   //     (e - lim) % V == 0
3249   //   Solving for lim:
3250   //     (e - lim0 + N) % V == 0
3251   //     N = (V - (e - lim0)) % V
3252   //     lim = lim0 - (V - (e - lim0)) % V
3253 
3254   int vw = vector_width_in_bytes(align_to_ref);
3255   int stride   = iv_stride();
3256   int scale    = align_to_ref_p.scale_in_bytes();
3257   int elt_size = align_to_ref_p.memory_size();
3258   int v_align  = vw / elt_size;
3259   assert(v_align > 1, "sanity");
3260   int offset   = align_to_ref_p.offset_in_bytes() / elt_size;
3261   Node *offsn  = _igvn.intcon(offset);
3262 
3263   Node *e = offsn;
3264   if (align_to_ref_p.invar() != NULL) {
3265     // incorporate any extra invariant piece producing (offset +/- invar) >>> log2(elt)
3266     Node* log2_elt = _igvn.intcon(exact_log2(elt_size));
3267     Node* invar = align_to_ref_p.invar();
3268     if (_igvn.type(invar)->isa_long()) {
3269       // Computations are done % (vector width/element size) so it's
3270       // safe to simply convert invar to an int and loose the upper 32
3271       // bit half.
3272       invar = new ConvL2INode(invar);
3273       _igvn.register_new_node_with_optimizer(invar);
3274     }
3275     Node* aref = new URShiftINode(invar, log2_elt);
3276     _igvn.register_new_node_with_optimizer(aref);
3277     _phase->set_ctrl(aref, pre_ctrl);
3278     if (align_to_ref_p.negate_invar()) {
3279       e = new SubINode(e, aref);
3280     } else {
3281       e = new AddINode(e, aref);
3282     }
3283     _igvn.register_new_node_with_optimizer(e);
3284     _phase->set_ctrl(e, pre_ctrl);
3285   }
3286   if (vw > ObjectAlignmentInBytes) {
3287     // incorporate base e +/- base && Mask >>> log2(elt)
3288     Node* xbase = new CastP2XNode(NULL, align_to_ref_p.base());
3289     _igvn.register_new_node_with_optimizer(xbase);
3290 #ifdef _LP64
3291     xbase  = new ConvL2INode(xbase);
3292     _igvn.register_new_node_with_optimizer(xbase);
3293 #endif
3294     Node* mask = _igvn.intcon(vw-1);
3295     Node* masked_xbase  = new AndINode(xbase, mask);
3296     _igvn.register_new_node_with_optimizer(masked_xbase);
3297     Node* log2_elt = _igvn.intcon(exact_log2(elt_size));
3298     Node* bref     = new URShiftINode(masked_xbase, log2_elt);
3299     _igvn.register_new_node_with_optimizer(bref);
3300     _phase->set_ctrl(bref, pre_ctrl);
3301     e = new AddINode(e, bref);
3302     _igvn.register_new_node_with_optimizer(e);
3303     _phase->set_ctrl(e, pre_ctrl);
3304   }
3305 
3306   // compute e +/- lim0
3307   if (scale < 0) {
3308     e = new SubINode(e, lim0);
3309   } else {
3310     e = new AddINode(e, lim0);
3311   }
3312   _igvn.register_new_node_with_optimizer(e);
3313   _phase->set_ctrl(e, pre_ctrl);
3314 
3315   if (stride * scale > 0) {
3316     // compute V - (e +/- lim0)
3317     Node* va  = _igvn.intcon(v_align);
3318     e = new SubINode(va, e);
3319     _igvn.register_new_node_with_optimizer(e);
3320     _phase->set_ctrl(e, pre_ctrl);
3321   }
3322   // compute N = (exp) % V
3323   Node* va_msk = _igvn.intcon(v_align - 1);
3324   Node* N = new AndINode(e, va_msk);
3325   _igvn.register_new_node_with_optimizer(N);
3326   _phase->set_ctrl(N, pre_ctrl);
3327 
3328   //   substitute back into (1), so that new limit
3329   //     lim = lim0 + N
3330   Node* lim;
3331   if (stride < 0) {
3332     lim = new SubINode(lim0, N);
3333   } else {
3334     lim = new AddINode(lim0, N);
3335   }
3336   _igvn.register_new_node_with_optimizer(lim);
3337   _phase->set_ctrl(lim, pre_ctrl);
3338   Node* constrained =
3339     (stride > 0) ? (Node*) new MinINode(lim, orig_limit)
3340                  : (Node*) new MaxINode(lim, orig_limit);
3341   _igvn.register_new_node_with_optimizer(constrained);
3342   _phase->set_ctrl(constrained, pre_ctrl);
3343   _igvn.replace_input_of(pre_opaq, 1, constrained);
3344 }
3345 
3346 //----------------------------get_pre_loop_end---------------------------
3347 // Find pre loop end from main loop.  Returns null if none.
3348 CountedLoopEndNode* SuperWord::get_pre_loop_end(CountedLoopNode* cl) {
3349   // The loop cannot be optimized if the graph shape at
3350   // the loop entry is inappropriate.
3351   if (!PhaseIdealLoop::is_canonical_loop_entry(cl)) {
3352     return NULL;
3353   }
3354 
3355   Node* p_f = cl->skip_predicates()->in(0)->in(0);
3356   if (!p_f->is_IfFalse()) return NULL;
3357   if (!p_f->in(0)->is_CountedLoopEnd()) return NULL;
3358   CountedLoopEndNode* pre_end = p_f->in(0)->as_CountedLoopEnd();
3359   CountedLoopNode* loop_node = pre_end->loopnode();
3360   if (loop_node == NULL || !loop_node->is_pre_loop()) return NULL;
3361   return pre_end;
3362 }
3363 
3364 //------------------------------init---------------------------
3365 void SuperWord::init() {
3366   _dg.init();
3367   _packset.clear();
3368   _disjoint_ptrs.clear();
3369   _block.clear();
3370   _post_block.clear();
3371   _data_entry.clear();
3372   _mem_slice_head.clear();
3373   _mem_slice_tail.clear();
3374   _iteration_first.clear();
3375   _iteration_last.clear();
3376   _node_info.clear();
3377   _align_to_ref = NULL;
3378   _lpt = NULL;
3379   _lp = NULL;
3380   _bb = NULL;
3381   _iv = NULL;
3382   _race_possible = 0;
3383   _early_return = false;
3384   _num_work_vecs = 0;
3385   _num_reductions = 0;
3386 }
3387 
3388 //------------------------------restart---------------------------
3389 void SuperWord::restart() {
3390   _dg.init();
3391   _packset.clear();
3392   _disjoint_ptrs.clear();
3393   _block.clear();
3394   _post_block.clear();
3395   _data_entry.clear();
3396   _mem_slice_head.clear();
3397   _mem_slice_tail.clear();
3398   _node_info.clear();
3399 }
3400 
3401 //------------------------------print_packset---------------------------
3402 void SuperWord::print_packset() {
3403 #ifndef PRODUCT
3404   tty->print_cr("packset");
3405   for (int i = 0; i < _packset.length(); i++) {
3406     tty->print_cr("Pack: %d", i);
3407     Node_List* p = _packset.at(i);
3408     print_pack(p);
3409   }
3410 #endif
3411 }
3412 
3413 //------------------------------print_pack---------------------------
3414 void SuperWord::print_pack(Node_List* p) {
3415   for (uint i = 0; i < p->size(); i++) {
3416     print_stmt(p->at(i));
3417   }
3418 }
3419 
3420 //------------------------------print_bb---------------------------
3421 void SuperWord::print_bb() {
3422 #ifndef PRODUCT
3423   tty->print_cr("\nBlock");
3424   for (int i = 0; i < _block.length(); i++) {
3425     Node* n = _block.at(i);
3426     tty->print("%d ", i);
3427     if (n) {
3428       n->dump();
3429     }
3430   }
3431 #endif
3432 }
3433 
3434 //------------------------------print_stmt---------------------------
3435 void SuperWord::print_stmt(Node* s) {
3436 #ifndef PRODUCT
3437   tty->print(" align: %d \t", alignment(s));
3438   s->dump();
3439 #endif
3440 }
3441 
3442 //------------------------------blank---------------------------
3443 char* SuperWord::blank(uint depth) {
3444   static char blanks[101];
3445   assert(depth < 101, "too deep");
3446   for (uint i = 0; i < depth; i++) blanks[i] = ' ';
3447   blanks[depth] = '\0';
3448   return blanks;
3449 }
3450 
3451 
3452 //==============================SWPointer===========================
3453 #ifndef PRODUCT
3454 int SWPointer::Tracer::_depth = 0;
3455 #endif
3456 //----------------------------SWPointer------------------------
3457 SWPointer::SWPointer(MemNode* mem, SuperWord* slp, Node_Stack *nstack, bool analyze_only) :
3458   _mem(mem), _slp(slp),  _base(NULL),  _adr(NULL),
3459   _scale(0), _offset(0), _invar(NULL), _negate_invar(false),
3460   _nstack(nstack), _analyze_only(analyze_only),
3461   _stack_idx(0)
3462 #ifndef PRODUCT
3463   , _tracer(slp)
3464 #endif
3465 {
3466   NOT_PRODUCT(_tracer.ctor_1(mem);)
3467 
3468   Node* adr = mem->in(MemNode::Address);
3469   if (!adr->is_AddP()) {
3470     assert(!valid(), "too complex");
3471     return;
3472   }
3473   // Match AddP(base, AddP(ptr, k*iv [+ invariant]), constant)
3474   Node* base = adr->in(AddPNode::Base);
3475   // The base address should be loop invariant
3476   if (!invariant(base)) {
3477     assert(!valid(), "base address is loop variant");
3478     return;
3479   }
3480   //unsafe reference could not be aligned appropriately without runtime checking
3481   if (base == NULL || base->bottom_type() == Type::TOP) {
3482     assert(!valid(), "unsafe access");
3483     return;
3484   }
3485 
3486   NOT_PRODUCT(if(_slp->is_trace_alignment()) _tracer.store_depth();)
3487   NOT_PRODUCT(_tracer.ctor_2(adr);)
3488 
3489   int i;
3490   for (i = 0; i < 3; i++) {
3491     NOT_PRODUCT(_tracer.ctor_3(adr, i);)
3492 
3493     if (!scaled_iv_plus_offset(adr->in(AddPNode::Offset))) {
3494       assert(!valid(), "too complex");
3495       return;
3496     }
3497     adr = adr->in(AddPNode::Address);
3498     NOT_PRODUCT(_tracer.ctor_4(adr, i);)
3499 
3500     if (base == adr || !adr->is_AddP()) {
3501       NOT_PRODUCT(_tracer.ctor_5(adr, base, i);)
3502       break; // stop looking at addp's
3503     }
3504   }
3505   NOT_PRODUCT(if(_slp->is_trace_alignment()) _tracer.restore_depth();)
3506   NOT_PRODUCT(_tracer.ctor_6(mem);)
3507 
3508   _base = base;
3509   _adr  = adr;
3510   assert(valid(), "Usable");
3511 }
3512 
3513 // Following is used to create a temporary object during
3514 // the pattern match of an address expression.
3515 SWPointer::SWPointer(SWPointer* p) :
3516   _mem(p->_mem), _slp(p->_slp),  _base(NULL),  _adr(NULL),
3517   _scale(0), _offset(0), _invar(NULL), _negate_invar(false),
3518   _nstack(p->_nstack), _analyze_only(p->_analyze_only),
3519   _stack_idx(p->_stack_idx)
3520   #ifndef PRODUCT
3521   , _tracer(p->_slp)
3522   #endif
3523 {}
3524 
3525 
3526 bool SWPointer::invariant(Node* n) {
3527   NOT_PRODUCT(Tracer::Depth dd;)
3528   Node *n_c = phase()->get_ctrl(n);
3529   NOT_PRODUCT(_tracer.invariant_1(n, n_c);)
3530   return !lpt()->is_member(phase()->get_loop(n_c));
3531 }
3532 //------------------------scaled_iv_plus_offset--------------------
3533 // Match: k*iv + offset
3534 // where: k is a constant that maybe zero, and
3535 //        offset is (k2 [+/- invariant]) where k2 maybe zero and invariant is optional
3536 bool SWPointer::scaled_iv_plus_offset(Node* n) {
3537   NOT_PRODUCT(Tracer::Depth ddd;)
3538   NOT_PRODUCT(_tracer.scaled_iv_plus_offset_1(n);)
3539 
3540   if (scaled_iv(n)) {
3541     NOT_PRODUCT(_tracer.scaled_iv_plus_offset_2(n);)
3542     return true;
3543   }
3544 
3545   if (offset_plus_k(n)) {
3546     NOT_PRODUCT(_tracer.scaled_iv_plus_offset_3(n);)
3547     return true;
3548   }
3549 
3550   int opc = n->Opcode();
3551   if (opc == Op_AddI) {
3552     if (scaled_iv(n->in(1)) && offset_plus_k(n->in(2))) {
3553       NOT_PRODUCT(_tracer.scaled_iv_plus_offset_4(n);)
3554       return true;
3555     }
3556     if (scaled_iv(n->in(2)) && offset_plus_k(n->in(1))) {
3557       NOT_PRODUCT(_tracer.scaled_iv_plus_offset_5(n);)
3558       return true;
3559     }
3560   } else if (opc == Op_SubI) {
3561     if (scaled_iv(n->in(1)) && offset_plus_k(n->in(2), true)) {
3562       NOT_PRODUCT(_tracer.scaled_iv_plus_offset_6(n);)
3563       return true;
3564     }
3565     if (scaled_iv(n->in(2)) && offset_plus_k(n->in(1))) {
3566       _scale *= -1;
3567       NOT_PRODUCT(_tracer.scaled_iv_plus_offset_7(n);)
3568       return true;
3569     }
3570   }
3571 
3572   NOT_PRODUCT(_tracer.scaled_iv_plus_offset_8(n);)
3573   return false;
3574 }
3575 
3576 //----------------------------scaled_iv------------------------
3577 // Match: k*iv where k is a constant that's not zero
3578 bool SWPointer::scaled_iv(Node* n) {
3579   NOT_PRODUCT(Tracer::Depth ddd;)
3580   NOT_PRODUCT(_tracer.scaled_iv_1(n);)
3581 
3582   if (_scale != 0) { // already found a scale
3583     NOT_PRODUCT(_tracer.scaled_iv_2(n, _scale);)
3584     return false;
3585   }
3586 
3587   if (n == iv()) {
3588     _scale = 1;
3589     NOT_PRODUCT(_tracer.scaled_iv_3(n, _scale);)
3590     return true;
3591   }
3592   if (_analyze_only && (invariant(n) == false)) {
3593     _nstack->push(n, _stack_idx++);
3594   }
3595 
3596   int opc = n->Opcode();
3597   if (opc == Op_MulI) {
3598     if (n->in(1) == iv() && n->in(2)->is_Con()) {
3599       _scale = n->in(2)->get_int();
3600       NOT_PRODUCT(_tracer.scaled_iv_4(n, _scale);)
3601       return true;
3602     } else if (n->in(2) == iv() && n->in(1)->is_Con()) {
3603       _scale = n->in(1)->get_int();
3604       NOT_PRODUCT(_tracer.scaled_iv_5(n, _scale);)
3605       return true;
3606     }
3607   } else if (opc == Op_LShiftI) {
3608     if (n->in(1) == iv() && n->in(2)->is_Con()) {
3609       _scale = 1 << n->in(2)->get_int();
3610       NOT_PRODUCT(_tracer.scaled_iv_6(n, _scale);)
3611       return true;
3612     }
3613   } else if (opc == Op_ConvI2L) {
3614     if (n->in(1)->Opcode() == Op_CastII &&
3615         n->in(1)->as_CastII()->has_range_check()) {
3616       // Skip range check dependent CastII nodes
3617       n = n->in(1);
3618     }
3619     if (scaled_iv_plus_offset(n->in(1))) {
3620       NOT_PRODUCT(_tracer.scaled_iv_7(n);)
3621       return true;
3622     }
3623   } else if (opc == Op_LShiftL) {
3624     if (!has_iv() && _invar == NULL) {
3625       // Need to preserve the current _offset value, so
3626       // create a temporary object for this expression subtree.
3627       // Hacky, so should re-engineer the address pattern match.
3628       NOT_PRODUCT(Tracer::Depth dddd;)
3629       SWPointer tmp(this);
3630       NOT_PRODUCT(_tracer.scaled_iv_8(n, &tmp);)
3631 
3632       if (tmp.scaled_iv_plus_offset(n->in(1))) {
3633         if (tmp._invar == NULL || _slp->do_vector_loop()) {
3634           int mult = 1 << n->in(2)->get_int();
3635           _scale   = tmp._scale  * mult;
3636           _offset += tmp._offset * mult;
3637           NOT_PRODUCT(_tracer.scaled_iv_9(n, _scale, _offset, mult);)
3638           return true;
3639         }
3640       }
3641     }
3642   }
3643   NOT_PRODUCT(_tracer.scaled_iv_10(n);)
3644   return false;
3645 }
3646 
3647 //----------------------------offset_plus_k------------------------
3648 // Match: offset is (k [+/- invariant])
3649 // where k maybe zero and invariant is optional, but not both.
3650 bool SWPointer::offset_plus_k(Node* n, bool negate) {
3651   NOT_PRODUCT(Tracer::Depth ddd;)
3652   NOT_PRODUCT(_tracer.offset_plus_k_1(n);)
3653 
3654   int opc = n->Opcode();
3655   if (opc == Op_ConI) {
3656     _offset += negate ? -(n->get_int()) : n->get_int();
3657     NOT_PRODUCT(_tracer.offset_plus_k_2(n, _offset);)
3658     return true;
3659   } else if (opc == Op_ConL) {
3660     // Okay if value fits into an int
3661     const TypeLong* t = n->find_long_type();
3662     if (t->higher_equal(TypeLong::INT)) {
3663       jlong loff = n->get_long();
3664       jint  off  = (jint)loff;
3665       _offset += negate ? -off : loff;
3666       NOT_PRODUCT(_tracer.offset_plus_k_3(n, _offset);)
3667       return true;
3668     }
3669     NOT_PRODUCT(_tracer.offset_plus_k_4(n);)
3670     return false;
3671   }
3672   if (_invar != NULL) { // already has an invariant
3673     NOT_PRODUCT(_tracer.offset_plus_k_5(n, _invar);)
3674     return false;
3675   }
3676 
3677   if (_analyze_only && (invariant(n) == false)) {
3678     _nstack->push(n, _stack_idx++);
3679   }
3680   if (opc == Op_AddI) {
3681     if (n->in(2)->is_Con() && invariant(n->in(1))) {
3682       _negate_invar = negate;
3683       _invar = n->in(1);
3684       _offset += negate ? -(n->in(2)->get_int()) : n->in(2)->get_int();
3685       NOT_PRODUCT(_tracer.offset_plus_k_6(n, _invar, _negate_invar, _offset);)
3686       return true;
3687     } else if (n->in(1)->is_Con() && invariant(n->in(2))) {
3688       _offset += negate ? -(n->in(1)->get_int()) : n->in(1)->get_int();
3689       _negate_invar = negate;
3690       _invar = n->in(2);
3691       NOT_PRODUCT(_tracer.offset_plus_k_7(n, _invar, _negate_invar, _offset);)
3692       return true;
3693     }
3694   }
3695   if (opc == Op_SubI) {
3696     if (n->in(2)->is_Con() && invariant(n->in(1))) {
3697       _negate_invar = negate;
3698       _invar = n->in(1);
3699       _offset += !negate ? -(n->in(2)->get_int()) : n->in(2)->get_int();
3700       NOT_PRODUCT(_tracer.offset_plus_k_8(n, _invar, _negate_invar, _offset);)
3701       return true;
3702     } else if (n->in(1)->is_Con() && invariant(n->in(2))) {
3703       _offset += negate ? -(n->in(1)->get_int()) : n->in(1)->get_int();
3704       _negate_invar = !negate;
3705       _invar = n->in(2);
3706       NOT_PRODUCT(_tracer.offset_plus_k_9(n, _invar, _negate_invar, _offset);)
3707       return true;
3708     }
3709   }
3710   if (invariant(n)) {
3711     if (opc == Op_ConvI2L) {
3712       n = n->in(1);
3713       if (n->Opcode() == Op_CastII &&
3714           n->as_CastII()->has_range_check()) {
3715         // Skip range check dependent CastII nodes
3716         assert(invariant(n), "sanity");
3717         n = n->in(1);
3718       }
3719     }
3720     _negate_invar = negate;
3721     _invar = n;
3722     NOT_PRODUCT(_tracer.offset_plus_k_10(n, _invar, _negate_invar, _offset);)
3723     return true;
3724   }
3725 
3726   NOT_PRODUCT(_tracer.offset_plus_k_11(n);)
3727   return false;
3728 }
3729 
3730 //----------------------------print------------------------
3731 void SWPointer::print() {
3732 #ifndef PRODUCT
3733   tty->print("base: %d  adr: %d  scale: %d  offset: %d  invar: %c%d\n",
3734              _base != NULL ? _base->_idx : 0,
3735              _adr  != NULL ? _adr->_idx  : 0,
3736              _scale, _offset,
3737              _negate_invar?'-':'+',
3738              _invar != NULL ? _invar->_idx : 0);
3739 #endif
3740 }
3741 
3742 //----------------------------tracing------------------------
3743 #ifndef PRODUCT
3744 void SWPointer::Tracer::print_depth() {
3745   for (int ii = 0; ii<_depth; ++ii) tty->print("  ");
3746 }
3747 
3748 void SWPointer::Tracer::ctor_1 (Node* mem) {
3749   if(_slp->is_trace_alignment()) {
3750     print_depth(); tty->print(" %d SWPointer::SWPointer: start alignment analysis", mem->_idx); mem->dump();
3751   }
3752 }
3753 
3754 void SWPointer::Tracer::ctor_2(Node* adr) {
3755   if(_slp->is_trace_alignment()) {
3756     //store_depth();
3757     inc_depth();
3758     print_depth(); tty->print(" %d (adr) SWPointer::SWPointer: ", adr->_idx); adr->dump();
3759     inc_depth();
3760     print_depth(); tty->print(" %d (base) SWPointer::SWPointer: ", adr->in(AddPNode::Base)->_idx); adr->in(AddPNode::Base)->dump();
3761   }
3762 }
3763 
3764 void SWPointer::Tracer::ctor_3(Node* adr, int i) {
3765   if(_slp->is_trace_alignment()) {
3766     inc_depth();
3767     Node* offset = adr->in(AddPNode::Offset);
3768     print_depth(); tty->print(" %d (offset) SWPointer::SWPointer: i = %d: ", offset->_idx, i); offset->dump();
3769   }
3770 }
3771 
3772 void SWPointer::Tracer::ctor_4(Node* adr, int i) {
3773   if(_slp->is_trace_alignment()) {
3774     inc_depth();
3775     print_depth(); tty->print(" %d (adr) SWPointer::SWPointer: i = %d: ", adr->_idx, i); adr->dump();
3776   }
3777 }
3778 
3779 void SWPointer::Tracer::ctor_5(Node* adr, Node* base, int i) {
3780   if(_slp->is_trace_alignment()) {
3781     inc_depth();
3782     if (base == adr) {
3783       print_depth(); tty->print_cr("  \\ %d (adr) == %d (base) SWPointer::SWPointer: breaking analysis at i = %d", adr->_idx, base->_idx, i);
3784     } else if (!adr->is_AddP()) {
3785       print_depth(); tty->print_cr("  \\ %d (adr) is NOT Addp SWPointer::SWPointer: breaking analysis at i = %d", adr->_idx, i);
3786     }
3787   }
3788 }
3789 
3790 void SWPointer::Tracer::ctor_6(Node* mem) {
3791   if(_slp->is_trace_alignment()) {
3792     //restore_depth();
3793     print_depth(); tty->print_cr(" %d (adr) SWPointer::SWPointer: stop analysis", mem->_idx);
3794   }
3795 }
3796 
3797 void SWPointer::Tracer::invariant_1(Node *n, Node *n_c) {
3798   if (_slp->do_vector_loop() && _slp->is_debug() && _slp->_lpt->is_member(_slp->_phase->get_loop(n_c)) != (int)_slp->in_bb(n)) {
3799     int is_member =  _slp->_lpt->is_member(_slp->_phase->get_loop(n_c));
3800     int in_bb     =  _slp->in_bb(n);
3801     print_depth(); tty->print("  \\ ");  tty->print_cr(" %d SWPointer::invariant  conditions differ: n_c %d", n->_idx, n_c->_idx);
3802     print_depth(); tty->print("  \\ ");  tty->print_cr("is_member %d, in_bb %d", is_member, in_bb);
3803     print_depth(); tty->print("  \\ ");  n->dump();
3804     print_depth(); tty->print("  \\ ");  n_c->dump();
3805   }
3806 }
3807 
3808 void SWPointer::Tracer::scaled_iv_plus_offset_1(Node* n) {
3809   if(_slp->is_trace_alignment()) {
3810     print_depth(); tty->print(" %d SWPointer::scaled_iv_plus_offset testing node: ", n->_idx);
3811     n->dump();
3812   }
3813 }
3814 
3815 void SWPointer::Tracer::scaled_iv_plus_offset_2(Node* n) {
3816   if(_slp->is_trace_alignment()) {
3817     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv_plus_offset: PASSED", n->_idx);
3818   }
3819 }
3820 
3821 void SWPointer::Tracer::scaled_iv_plus_offset_3(Node* n) {
3822   if(_slp->is_trace_alignment()) {
3823     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv_plus_offset: PASSED", n->_idx);
3824   }
3825 }
3826 
3827 void SWPointer::Tracer::scaled_iv_plus_offset_4(Node* n) {
3828   if(_slp->is_trace_alignment()) {
3829     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv_plus_offset: Op_AddI PASSED", n->_idx);
3830     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv_plus_offset: in(1) is scaled_iv: ", n->in(1)->_idx); n->in(1)->dump();
3831     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv_plus_offset: in(2) is offset_plus_k: ", n->in(2)->_idx); n->in(2)->dump();
3832   }
3833 }
3834 
3835 void SWPointer::Tracer::scaled_iv_plus_offset_5(Node* n) {
3836   if(_slp->is_trace_alignment()) {
3837     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv_plus_offset: Op_AddI PASSED", n->_idx);
3838     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv_plus_offset: in(2) is scaled_iv: ", n->in(2)->_idx); n->in(2)->dump();
3839     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv_plus_offset: in(1) is offset_plus_k: ", n->in(1)->_idx); n->in(1)->dump();
3840   }
3841 }
3842 
3843 void SWPointer::Tracer::scaled_iv_plus_offset_6(Node* n) {
3844   if(_slp->is_trace_alignment()) {
3845     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv_plus_offset: Op_SubI PASSED", n->_idx);
3846     print_depth(); tty->print("  \\  %d SWPointer::scaled_iv_plus_offset: in(1) is scaled_iv: ", n->in(1)->_idx); n->in(1)->dump();
3847     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv_plus_offset: in(2) is offset_plus_k: ", n->in(2)->_idx); n->in(2)->dump();
3848   }
3849 }
3850 
3851 void SWPointer::Tracer::scaled_iv_plus_offset_7(Node* n) {
3852   if(_slp->is_trace_alignment()) {
3853     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv_plus_offset: Op_SubI PASSED", n->_idx);
3854     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv_plus_offset: in(2) is scaled_iv: ", n->in(2)->_idx); n->in(2)->dump();
3855     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv_plus_offset: in(1) is offset_plus_k: ", n->in(1)->_idx); n->in(1)->dump();
3856   }
3857 }
3858 
3859 void SWPointer::Tracer::scaled_iv_plus_offset_8(Node* n) {
3860   if(_slp->is_trace_alignment()) {
3861     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv_plus_offset: FAILED", n->_idx);
3862   }
3863 }
3864 
3865 void SWPointer::Tracer::scaled_iv_1(Node* n) {
3866   if(_slp->is_trace_alignment()) {
3867     print_depth(); tty->print(" %d SWPointer::scaled_iv: testing node: ", n->_idx); n->dump();
3868   }
3869 }
3870 
3871 void SWPointer::Tracer::scaled_iv_2(Node* n, int scale) {
3872   if(_slp->is_trace_alignment()) {
3873     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: FAILED since another _scale has been detected before", n->_idx);
3874     print_depth(); tty->print_cr("  \\ SWPointer::scaled_iv: _scale (%d) != 0", scale);
3875   }
3876 }
3877 
3878 void SWPointer::Tracer::scaled_iv_3(Node* n, int scale) {
3879   if(_slp->is_trace_alignment()) {
3880     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: is iv, setting _scale = %d", n->_idx, scale);
3881   }
3882 }
3883 
3884 void SWPointer::Tracer::scaled_iv_4(Node* n, int scale) {
3885   if(_slp->is_trace_alignment()) {
3886     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: Op_MulI PASSED, setting _scale = %d", n->_idx, scale);
3887     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv: in(1) is iv: ", n->in(1)->_idx); n->in(1)->dump();
3888     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv: in(2) is Con: ", n->in(2)->_idx); n->in(2)->dump();
3889   }
3890 }
3891 
3892 void SWPointer::Tracer::scaled_iv_5(Node* n, int scale) {
3893   if(_slp->is_trace_alignment()) {
3894     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: Op_MulI PASSED, setting _scale = %d", n->_idx, scale);
3895     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv: in(2) is iv: ", n->in(2)->_idx); n->in(2)->dump();
3896     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv: in(1) is Con: ", n->in(1)->_idx); n->in(1)->dump();
3897   }
3898 }
3899 
3900 void SWPointer::Tracer::scaled_iv_6(Node* n, int scale) {
3901   if(_slp->is_trace_alignment()) {
3902     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: Op_LShiftI PASSED, setting _scale = %d", n->_idx, scale);
3903     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv: in(1) is iv: ", n->in(1)->_idx); n->in(1)->dump();
3904     print_depth(); tty->print("  \\ %d SWPointer::scaled_iv: in(2) is Con: ", n->in(2)->_idx); n->in(2)->dump();
3905   }
3906 }
3907 
3908 void SWPointer::Tracer::scaled_iv_7(Node* n) {
3909   if(_slp->is_trace_alignment()) {
3910     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: Op_ConvI2L PASSED", n->_idx);
3911     print_depth(); tty->print_cr("  \\ SWPointer::scaled_iv: in(1) %d is scaled_iv_plus_offset: ", n->in(1)->_idx);
3912     inc_depth(); inc_depth();
3913     print_depth(); n->in(1)->dump();
3914     dec_depth(); dec_depth();
3915   }
3916 }
3917 
3918 void SWPointer::Tracer::scaled_iv_8(Node* n, SWPointer* tmp) {
3919   if(_slp->is_trace_alignment()) {
3920     print_depth(); tty->print(" %d SWPointer::scaled_iv: Op_LShiftL, creating tmp SWPointer: ", n->_idx); tmp->print();
3921   }
3922 }
3923 
3924 void SWPointer::Tracer::scaled_iv_9(Node* n, int scale, int _offset, int mult) {
3925   if(_slp->is_trace_alignment()) {
3926     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: Op_LShiftL PASSED, setting _scale = %d, _offset = %d", n->_idx, scale, _offset);
3927     print_depth(); tty->print_cr("  \\ SWPointer::scaled_iv: in(1) %d is scaled_iv_plus_offset, in(2) %d used to get mult = %d: _scale = %d, _offset = %d",
3928     n->in(1)->_idx, n->in(2)->_idx, mult, scale, _offset);
3929     inc_depth(); inc_depth();
3930     print_depth(); n->in(1)->dump();
3931     print_depth(); n->in(2)->dump();
3932     dec_depth(); dec_depth();
3933   }
3934 }
3935 
3936 void SWPointer::Tracer::scaled_iv_10(Node* n) {
3937   if(_slp->is_trace_alignment()) {
3938     print_depth(); tty->print_cr(" %d SWPointer::scaled_iv: FAILED", n->_idx);
3939   }
3940 }
3941 
3942 void SWPointer::Tracer::offset_plus_k_1(Node* n) {
3943   if(_slp->is_trace_alignment()) {
3944     print_depth(); tty->print(" %d SWPointer::offset_plus_k: testing node: ", n->_idx); n->dump();
3945   }
3946 }
3947 
3948 void SWPointer::Tracer::offset_plus_k_2(Node* n, int _offset) {
3949   if(_slp->is_trace_alignment()) {
3950     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: Op_ConI PASSED, setting _offset = %d", n->_idx, _offset);
3951   }
3952 }
3953 
3954 void SWPointer::Tracer::offset_plus_k_3(Node* n, int _offset) {
3955   if(_slp->is_trace_alignment()) {
3956     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: Op_ConL PASSED, setting _offset = %d", n->_idx, _offset);
3957   }
3958 }
3959 
3960 void SWPointer::Tracer::offset_plus_k_4(Node* n) {
3961   if(_slp->is_trace_alignment()) {
3962     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: FAILED", n->_idx);
3963     print_depth(); tty->print_cr("  \\ " JLONG_FORMAT " SWPointer::offset_plus_k: Op_ConL FAILED, k is too big", n->get_long());
3964   }
3965 }
3966 
3967 void SWPointer::Tracer::offset_plus_k_5(Node* n, Node* _invar) {
3968   if(_slp->is_trace_alignment()) {
3969     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: FAILED since another invariant has been detected before", n->_idx);
3970     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: _invar != NULL: ", _invar->_idx); _invar->dump();
3971   }
3972 }
3973 
3974 void SWPointer::Tracer::offset_plus_k_6(Node* n, Node* _invar, bool _negate_invar, int _offset) {
3975   if(_slp->is_trace_alignment()) {
3976     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: Op_AddI PASSED, setting _negate_invar = %d, _invar = %d, _offset = %d",
3977     n->_idx, _negate_invar, _invar->_idx, _offset);
3978     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(2) is Con: ", n->in(2)->_idx); n->in(2)->dump();
3979     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(1) is invariant: ", _invar->_idx); _invar->dump();
3980   }
3981 }
3982 
3983 void SWPointer::Tracer::offset_plus_k_7(Node* n, Node* _invar, bool _negate_invar, int _offset) {
3984   if(_slp->is_trace_alignment()) {
3985     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: Op_AddI PASSED, setting _negate_invar = %d, _invar = %d, _offset = %d",
3986     n->_idx, _negate_invar, _invar->_idx, _offset);
3987     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(1) is Con: ", n->in(1)->_idx); n->in(1)->dump();
3988     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(2) is invariant: ", _invar->_idx); _invar->dump();
3989   }
3990 }
3991 
3992 void SWPointer::Tracer::offset_plus_k_8(Node* n, Node* _invar, bool _negate_invar, int _offset) {
3993   if(_slp->is_trace_alignment()) {
3994     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: Op_SubI is PASSED, setting _negate_invar = %d, _invar = %d, _offset = %d",
3995     n->_idx, _negate_invar, _invar->_idx, _offset);
3996     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(2) is Con: ", n->in(2)->_idx); n->in(2)->dump();
3997     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(1) is invariant: ", _invar->_idx); _invar->dump();
3998   }
3999 }
4000 
4001 void SWPointer::Tracer::offset_plus_k_9(Node* n, Node* _invar, bool _negate_invar, int _offset) {
4002   if(_slp->is_trace_alignment()) {
4003     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: Op_SubI PASSED, setting _negate_invar = %d, _invar = %d, _offset = %d", n->_idx, _negate_invar, _invar->_idx, _offset);
4004     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(1) is Con: ", n->in(1)->_idx); n->in(1)->dump();
4005     print_depth(); tty->print("  \\ %d SWPointer::offset_plus_k: in(2) is invariant: ", _invar->_idx); _invar->dump();
4006   }
4007 }
4008 
4009 void SWPointer::Tracer::offset_plus_k_10(Node* n, Node* _invar, bool _negate_invar, int _offset) {
4010   if(_slp->is_trace_alignment()) {
4011     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: PASSED, setting _negate_invar = %d, _invar = %d, _offset = %d", n->_idx, _negate_invar, _invar->_idx, _offset);
4012     print_depth(); tty->print_cr("  \\ %d SWPointer::offset_plus_k: is invariant", n->_idx);
4013   }
4014 }
4015 
4016 void SWPointer::Tracer::offset_plus_k_11(Node* n) {
4017   if(_slp->is_trace_alignment()) {
4018     print_depth(); tty->print_cr(" %d SWPointer::offset_plus_k: FAILED", n->_idx);
4019   }
4020 }
4021 
4022 #endif
4023 // ========================= OrderedPair =====================
4024 
4025 const OrderedPair OrderedPair::initial;
4026 
4027 // ========================= SWNodeInfo =====================
4028 
4029 const SWNodeInfo SWNodeInfo::initial;
4030 
4031 
4032 // ============================ DepGraph ===========================
4033 
4034 //------------------------------make_node---------------------------
4035 // Make a new dependence graph node for an ideal node.
4036 DepMem* DepGraph::make_node(Node* node) {
4037   DepMem* m = new (_arena) DepMem(node);
4038   if (node != NULL) {
4039     assert(_map.at_grow(node->_idx) == NULL, "one init only");
4040     _map.at_put_grow(node->_idx, m);
4041   }
4042   return m;
4043 }
4044 
4045 //------------------------------make_edge---------------------------
4046 // Make a new dependence graph edge from dpred -> dsucc
4047 DepEdge* DepGraph::make_edge(DepMem* dpred, DepMem* dsucc) {
4048   DepEdge* e = new (_arena) DepEdge(dpred, dsucc, dsucc->in_head(), dpred->out_head());
4049   dpred->set_out_head(e);
4050   dsucc->set_in_head(e);
4051   return e;
4052 }
4053 
4054 // ========================== DepMem ========================
4055 
4056 //------------------------------in_cnt---------------------------
4057 int DepMem::in_cnt() {
4058   int ct = 0;
4059   for (DepEdge* e = _in_head; e != NULL; e = e->next_in()) ct++;
4060   return ct;
4061 }
4062 
4063 //------------------------------out_cnt---------------------------
4064 int DepMem::out_cnt() {
4065   int ct = 0;
4066   for (DepEdge* e = _out_head; e != NULL; e = e->next_out()) ct++;
4067   return ct;
4068 }
4069 
4070 //------------------------------print-----------------------------
4071 void DepMem::print() {
4072 #ifndef PRODUCT
4073   tty->print("  DepNode %d (", _node->_idx);
4074   for (DepEdge* p = _in_head; p != NULL; p = p->next_in()) {
4075     Node* pred = p->pred()->node();
4076     tty->print(" %d", pred != NULL ? pred->_idx : 0);
4077   }
4078   tty->print(") [");
4079   for (DepEdge* s = _out_head; s != NULL; s = s->next_out()) {
4080     Node* succ = s->succ()->node();
4081     tty->print(" %d", succ != NULL ? succ->_idx : 0);
4082   }
4083   tty->print_cr(" ]");
4084 #endif
4085 }
4086 
4087 // =========================== DepEdge =========================
4088 
4089 //------------------------------DepPreds---------------------------
4090 void DepEdge::print() {
4091 #ifndef PRODUCT
4092   tty->print_cr("DepEdge: %d [ %d ]", _pred->node()->_idx, _succ->node()->_idx);
4093 #endif
4094 }
4095 
4096 // =========================== DepPreds =========================
4097 // Iterator over predecessor edges in the dependence graph.
4098 
4099 //------------------------------DepPreds---------------------------
4100 DepPreds::DepPreds(Node* n, DepGraph& dg) {
4101   _n = n;
4102   _done = false;
4103   if (_n->is_Store() || _n->is_Load()) {
4104     _next_idx = MemNode::Address;
4105     _end_idx  = n->req();
4106     _dep_next = dg.dep(_n)->in_head();
4107   } else if (_n->is_Mem()) {
4108     _next_idx = 0;
4109     _end_idx  = 0;
4110     _dep_next = dg.dep(_n)->in_head();
4111   } else {
4112     _next_idx = 1;
4113     _end_idx  = _n->req();
4114     _dep_next = NULL;
4115   }
4116   next();
4117 }
4118 
4119 //------------------------------next---------------------------
4120 void DepPreds::next() {
4121   if (_dep_next != NULL) {
4122     _current  = _dep_next->pred()->node();
4123     _dep_next = _dep_next->next_in();
4124   } else if (_next_idx < _end_idx) {
4125     _current  = _n->in(_next_idx++);
4126   } else {
4127     _done = true;
4128   }
4129 }
4130 
4131 // =========================== DepSuccs =========================
4132 // Iterator over successor edges in the dependence graph.
4133 
4134 //------------------------------DepSuccs---------------------------
4135 DepSuccs::DepSuccs(Node* n, DepGraph& dg) {
4136   _n = n;
4137   _done = false;
4138   if (_n->is_Load()) {
4139     _next_idx = 0;
4140     _end_idx  = _n->outcnt();
4141     _dep_next = dg.dep(_n)->out_head();
4142   } else if (_n->is_Mem() || (_n->is_Phi() && _n->bottom_type() == Type::MEMORY)) {
4143     _next_idx = 0;
4144     _end_idx  = 0;
4145     _dep_next = dg.dep(_n)->out_head();
4146   } else {
4147     _next_idx = 0;
4148     _end_idx  = _n->outcnt();
4149     _dep_next = NULL;
4150   }
4151   next();
4152 }
4153 
4154 //-------------------------------next---------------------------
4155 void DepSuccs::next() {
4156   if (_dep_next != NULL) {
4157     _current  = _dep_next->succ()->node();
4158     _dep_next = _dep_next->next_out();
4159   } else if (_next_idx < _end_idx) {
4160     _current  = _n->raw_out(_next_idx++);
4161   } else {
4162     _done = true;
4163   }
4164 }
4165 
4166 //
4167 // --------------------------------- vectorization/simd -----------------------------------
4168 //
4169 bool SuperWord::same_origin_idx(Node* a, Node* b) const {
4170   return a != NULL && b != NULL && _clone_map.same_idx(a->_idx, b->_idx);
4171 }
4172 bool SuperWord::same_generation(Node* a, Node* b) const {
4173   return a != NULL && b != NULL && _clone_map.same_gen(a->_idx, b->_idx);
4174 }
4175 
4176 Node*  SuperWord::find_phi_for_mem_dep(LoadNode* ld) {
4177   assert(in_bb(ld), "must be in block");
4178   if (_clone_map.gen(ld->_idx) == _ii_first) {
4179 #ifndef PRODUCT
4180     if (_vector_loop_debug) {
4181       tty->print_cr("SuperWord::find_phi_for_mem_dep _clone_map.gen(ld->_idx)=%d",
4182         _clone_map.gen(ld->_idx));
4183     }
4184 #endif
4185     return NULL; //we think that any ld in the first gen being vectorizable
4186   }
4187 
4188   Node* mem = ld->in(MemNode::Memory);
4189   if (mem->outcnt() <= 1) {
4190     // we don't want to remove the only edge from mem node to load
4191 #ifndef PRODUCT
4192     if (_vector_loop_debug) {
4193       tty->print_cr("SuperWord::find_phi_for_mem_dep input node %d to load %d has no other outputs and edge mem->load cannot be removed",
4194         mem->_idx, ld->_idx);
4195       ld->dump();
4196       mem->dump();
4197     }
4198 #endif
4199     return NULL;
4200   }
4201   if (!in_bb(mem) || same_generation(mem, ld)) {
4202 #ifndef PRODUCT
4203     if (_vector_loop_debug) {
4204       tty->print_cr("SuperWord::find_phi_for_mem_dep _clone_map.gen(mem->_idx)=%d",
4205         _clone_map.gen(mem->_idx));
4206     }
4207 #endif
4208     return NULL; // does not depend on loop volatile node or depends on the same generation
4209   }
4210 
4211   //otherwise first node should depend on mem-phi
4212   Node* first = first_node(ld);
4213   assert(first->is_Load(), "must be Load");
4214   Node* phi = first->as_Load()->in(MemNode::Memory);
4215   if (!phi->is_Phi() || phi->bottom_type() != Type::MEMORY) {
4216 #ifndef PRODUCT
4217     if (_vector_loop_debug) {
4218       tty->print_cr("SuperWord::find_phi_for_mem_dep load is not vectorizable node, since it's `first` does not take input from mem phi");
4219       ld->dump();
4220       first->dump();
4221     }
4222 #endif
4223     return NULL;
4224   }
4225 
4226   Node* tail = 0;
4227   for (int m = 0; m < _mem_slice_head.length(); m++) {
4228     if (_mem_slice_head.at(m) == phi) {
4229       tail = _mem_slice_tail.at(m);
4230     }
4231   }
4232   if (tail == 0) { //test that found phi is in the list  _mem_slice_head
4233 #ifndef PRODUCT
4234     if (_vector_loop_debug) {
4235       tty->print_cr("SuperWord::find_phi_for_mem_dep load %d is not vectorizable node, its phi %d is not _mem_slice_head",
4236         ld->_idx, phi->_idx);
4237       ld->dump();
4238       phi->dump();
4239     }
4240 #endif
4241     return NULL;
4242   }
4243 
4244   // now all conditions are met
4245   return phi;
4246 }
4247 
4248 Node* SuperWord::first_node(Node* nd) {
4249   for (int ii = 0; ii < _iteration_first.length(); ii++) {
4250     Node* nnn = _iteration_first.at(ii);
4251     if (same_origin_idx(nnn, nd)) {
4252 #ifndef PRODUCT
4253       if (_vector_loop_debug) {
4254         tty->print_cr("SuperWord::first_node: %d is the first iteration node for %d (_clone_map.idx(nnn->_idx) = %d)",
4255           nnn->_idx, nd->_idx, _clone_map.idx(nnn->_idx));
4256       }
4257 #endif
4258       return nnn;
4259     }
4260   }
4261 
4262 #ifndef PRODUCT
4263   if (_vector_loop_debug) {
4264     tty->print_cr("SuperWord::first_node: did not find first iteration node for %d (_clone_map.idx(nd->_idx)=%d)",
4265       nd->_idx, _clone_map.idx(nd->_idx));
4266   }
4267 #endif
4268   return 0;
4269 }
4270 
4271 Node* SuperWord::last_node(Node* nd) {
4272   for (int ii = 0; ii < _iteration_last.length(); ii++) {
4273     Node* nnn = _iteration_last.at(ii);
4274     if (same_origin_idx(nnn, nd)) {
4275 #ifndef PRODUCT
4276       if (_vector_loop_debug) {
4277         tty->print_cr("SuperWord::last_node _clone_map.idx(nnn->_idx)=%d, _clone_map.idx(nd->_idx)=%d",
4278           _clone_map.idx(nnn->_idx), _clone_map.idx(nd->_idx));
4279       }
4280 #endif
4281       return nnn;
4282     }
4283   }
4284   return 0;
4285 }
4286 
4287 int SuperWord::mark_generations() {
4288   Node *ii_err = NULL, *tail_err = NULL;
4289   for (int i = 0; i < _mem_slice_head.length(); i++) {
4290     Node* phi  = _mem_slice_head.at(i);
4291     assert(phi->is_Phi(), "must be phi");
4292 
4293     Node* tail = _mem_slice_tail.at(i);
4294     if (_ii_last == -1) {
4295       tail_err = tail;
4296       _ii_last = _clone_map.gen(tail->_idx);
4297     }
4298     else if (_ii_last != _clone_map.gen(tail->_idx)) {
4299 #ifndef PRODUCT
4300       if (TraceSuperWord && Verbose) {
4301         tty->print_cr("SuperWord::mark_generations _ii_last error - found different generations in two tail nodes ");
4302         tail->dump();
4303         tail_err->dump();
4304       }
4305 #endif
4306       return -1;
4307     }
4308 
4309     // find first iteration in the loop
4310     for (DUIterator_Fast imax, i = phi->fast_outs(imax); i < imax; i++) {
4311       Node* ii = phi->fast_out(i);
4312       if (in_bb(ii) && ii->is_Store()) { // we speculate that normally Stores of one and one only generation have deps from mem phi
4313         if (_ii_first == -1) {
4314           ii_err = ii;
4315           _ii_first = _clone_map.gen(ii->_idx);
4316         } else if (_ii_first != _clone_map.gen(ii->_idx)) {
4317 #ifndef PRODUCT
4318           if (TraceSuperWord && Verbose) {
4319             tty->print_cr("SuperWord::mark_generations: _ii_first was found before and not equal to one in this node (%d)", _ii_first);
4320             ii->dump();
4321             if (ii_err!= 0) {
4322               ii_err->dump();
4323             }
4324           }
4325 #endif
4326           return -1; // this phi has Stores from different generations of unroll and cannot be simd/vectorized
4327         }
4328       }
4329     }//for (DUIterator_Fast imax,
4330   }//for (int i...
4331 
4332   if (_ii_first == -1 || _ii_last == -1) {
4333     if (TraceSuperWord && Verbose) {
4334       tty->print_cr("SuperWord::mark_generations unknown error, something vent wrong");
4335     }
4336     return -1; // something vent wrong
4337   }
4338   // collect nodes in the first and last generations
4339   assert(_iteration_first.length() == 0, "_iteration_first must be empty");
4340   assert(_iteration_last.length() == 0, "_iteration_last must be empty");
4341   for (int j = 0; j < _block.length(); j++) {
4342     Node* n = _block.at(j);
4343     node_idx_t gen = _clone_map.gen(n->_idx);
4344     if ((signed)gen == _ii_first) {
4345       _iteration_first.push(n);
4346     } else if ((signed)gen == _ii_last) {
4347       _iteration_last.push(n);
4348     }
4349   }
4350 
4351   // building order of iterations
4352   if (_ii_order.length() == 0 && ii_err != 0) {
4353     assert(in_bb(ii_err) && ii_err->is_Store(), "should be Store in bb");
4354     Node* nd = ii_err;
4355     while(_clone_map.gen(nd->_idx) != _ii_last) {
4356       _ii_order.push(_clone_map.gen(nd->_idx));
4357       bool found = false;
4358       for (DUIterator_Fast imax, i = nd->fast_outs(imax); i < imax; i++) {
4359         Node* use = nd->fast_out(i);
4360         if (same_origin_idx(use, nd) && use->as_Store()->in(MemNode::Memory) == nd) {
4361           found = true;
4362           nd = use;
4363           break;
4364         }
4365       }//for
4366 
4367       if (found == false) {
4368         if (TraceSuperWord && Verbose) {
4369           tty->print_cr("SuperWord::mark_generations: Cannot build order of iterations - no dependent Store for %d", nd->_idx);
4370         }
4371         _ii_order.clear();
4372         return -1;
4373       }
4374     } //while
4375     _ii_order.push(_clone_map.gen(nd->_idx));
4376   }
4377 
4378 #ifndef PRODUCT
4379   if (_vector_loop_debug) {
4380     tty->print_cr("SuperWord::mark_generations");
4381     tty->print_cr("First generation (%d) nodes:", _ii_first);
4382     for (int ii = 0; ii < _iteration_first.length(); ii++)  _iteration_first.at(ii)->dump();
4383     tty->print_cr("Last generation (%d) nodes:", _ii_last);
4384     for (int ii = 0; ii < _iteration_last.length(); ii++)  _iteration_last.at(ii)->dump();
4385     tty->print_cr(" ");
4386 
4387     tty->print("SuperWord::List of generations: ");
4388     for (int jj = 0; jj < _ii_order.length(); ++jj) {
4389       tty->print("%d:%d ", jj, _ii_order.at(jj));
4390     }
4391     tty->print_cr(" ");
4392   }
4393 #endif
4394 
4395   return _ii_first;
4396 }
4397 
4398 bool SuperWord::fix_commutative_inputs(Node* gold, Node* fix) {
4399   assert(gold->is_Add() && fix->is_Add() || gold->is_Mul() && fix->is_Mul(), "should be only Add or Mul nodes");
4400   assert(same_origin_idx(gold, fix), "should be clones of the same node");
4401   Node* gin1 = gold->in(1);
4402   Node* gin2 = gold->in(2);
4403   Node* fin1 = fix->in(1);
4404   Node* fin2 = fix->in(2);
4405   bool swapped = false;
4406 
4407   if (in_bb(gin1) && in_bb(gin2) && in_bb(fin1) && in_bb(fin1)) {
4408     if (same_origin_idx(gin1, fin1) &&
4409         same_origin_idx(gin2, fin2)) {
4410       return true; // nothing to fix
4411     }
4412     if (same_origin_idx(gin1, fin2) &&
4413         same_origin_idx(gin2, fin1)) {
4414       fix->swap_edges(1, 2);
4415       swapped = true;
4416     }
4417   }
4418   // at least one input comes from outside of bb
4419   if (gin1->_idx == fin1->_idx)  {
4420     return true; // nothing to fix
4421   }
4422   if (!swapped && (gin1->_idx == fin2->_idx || gin2->_idx == fin1->_idx))  { //swapping is expensive, check condition first
4423     fix->swap_edges(1, 2);
4424     swapped = true;
4425   }
4426 
4427   if (swapped) {
4428 #ifndef PRODUCT
4429     if (_vector_loop_debug) {
4430       tty->print_cr("SuperWord::fix_commutative_inputs: fixed node %d", fix->_idx);
4431     }
4432 #endif
4433     return true;
4434   }
4435 
4436   if (TraceSuperWord && Verbose) {
4437     tty->print_cr("SuperWord::fix_commutative_inputs: cannot fix node %d", fix->_idx);
4438   }
4439 
4440   return false;
4441 }
4442 
4443 bool SuperWord::pack_parallel() {
4444 #ifndef PRODUCT
4445   if (_vector_loop_debug) {
4446     tty->print_cr("SuperWord::pack_parallel: START");
4447   }
4448 #endif
4449 
4450   _packset.clear();
4451 
4452   for (int ii = 0; ii < _iteration_first.length(); ii++) {
4453     Node* nd = _iteration_first.at(ii);
4454     if (in_bb(nd) && (nd->is_Load() || nd->is_Store() || nd->is_Add() || nd->is_Mul())) {
4455       Node_List* pk = new Node_List();
4456       pk->push(nd);
4457       for (int gen = 1; gen < _ii_order.length(); ++gen) {
4458         for (int kk = 0; kk < _block.length(); kk++) {
4459           Node* clone = _block.at(kk);
4460           if (same_origin_idx(clone, nd) &&
4461               _clone_map.gen(clone->_idx) == _ii_order.at(gen)) {
4462             if (nd->is_Add() || nd->is_Mul()) {
4463               fix_commutative_inputs(nd, clone);
4464             }
4465             pk->push(clone);
4466             if (pk->size() == 4) {
4467               _packset.append(pk);
4468 #ifndef PRODUCT
4469               if (_vector_loop_debug) {
4470                 tty->print_cr("SuperWord::pack_parallel: added pack ");
4471                 pk->dump();
4472               }
4473 #endif
4474               if (_clone_map.gen(clone->_idx) != _ii_last) {
4475                 pk = new Node_List();
4476               }
4477             }
4478             break;
4479           }
4480         }
4481       }//for
4482     }//if
4483   }//for
4484 
4485 #ifndef PRODUCT
4486   if (_vector_loop_debug) {
4487     tty->print_cr("SuperWord::pack_parallel: END");
4488   }
4489 #endif
4490 
4491   return true;
4492 }
4493 
4494 bool SuperWord::hoist_loads_in_graph() {
4495   GrowableArray<Node*> loads;
4496 
4497 #ifndef PRODUCT
4498   if (_vector_loop_debug) {
4499     tty->print_cr("SuperWord::hoist_loads_in_graph: total number _mem_slice_head.length() = %d", _mem_slice_head.length());
4500   }
4501 #endif
4502 
4503   for (int i = 0; i < _mem_slice_head.length(); i++) {
4504     Node* n = _mem_slice_head.at(i);
4505     if ( !in_bb(n) || !n->is_Phi() || n->bottom_type() != Type::MEMORY) {
4506       if (TraceSuperWord && Verbose) {
4507         tty->print_cr("SuperWord::hoist_loads_in_graph: skipping unexpected node n=%d", n->_idx);
4508       }
4509       continue;
4510     }
4511 
4512 #ifndef PRODUCT
4513     if (_vector_loop_debug) {
4514       tty->print_cr("SuperWord::hoist_loads_in_graph: processing phi %d  = _mem_slice_head.at(%d);", n->_idx, i);
4515     }
4516 #endif
4517 
4518     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4519       Node* ld = n->fast_out(i);
4520       if (ld->is_Load() && ld->as_Load()->in(MemNode::Memory) == n && in_bb(ld)) {
4521         for (int i = 0; i < _block.length(); i++) {
4522           Node* ld2 = _block.at(i);
4523           if (ld2->is_Load() && same_origin_idx(ld, ld2) &&
4524               !same_generation(ld, ld2)) { // <= do not collect the first generation ld
4525 #ifndef PRODUCT
4526             if (_vector_loop_debug) {
4527               tty->print_cr("SuperWord::hoist_loads_in_graph: will try to hoist load ld2->_idx=%d, cloned from %d (ld->_idx=%d)",
4528                 ld2->_idx, _clone_map.idx(ld->_idx), ld->_idx);
4529             }
4530 #endif
4531             // could not do on-the-fly, since iterator is immutable
4532             loads.push(ld2);
4533           }
4534         }// for
4535       }//if
4536     }//for (DUIterator_Fast imax,
4537   }//for (int i = 0; i
4538 
4539   for (int i = 0; i < loads.length(); i++) {
4540     LoadNode* ld = loads.at(i)->as_Load();
4541     Node* phi = find_phi_for_mem_dep(ld);
4542     if (phi != NULL) {
4543 #ifndef PRODUCT
4544       if (_vector_loop_debug) {
4545         tty->print_cr("SuperWord::hoist_loads_in_graph replacing MemNode::Memory(%d) edge in %d with one from %d",
4546           MemNode::Memory, ld->_idx, phi->_idx);
4547       }
4548 #endif
4549       _igvn.replace_input_of(ld, MemNode::Memory, phi);
4550     }
4551   }//for
4552 
4553   restart(); // invalidate all basic structures, since we rebuilt the graph
4554 
4555   if (TraceSuperWord && Verbose) {
4556     tty->print_cr("\nSuperWord::hoist_loads_in_graph() the graph was rebuilt, all structures invalidated and need rebuild");
4557   }
4558 
4559   return true;
4560 }