rev 7539 : 8011858: Use Compile::live_nodes() instead of Compile::unique() in appropriate places
Reviewed-by: kvn, vlivanov
Contributed-by: vlad.ureche@gmail.com

   1 /*
   2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "memory/allocation.inline.hpp"
  27 #include "opto/block.hpp"
  28 #include "opto/callnode.hpp"
  29 #include "opto/cfgnode.hpp"
  30 #include "opto/connode.hpp"
  31 #include "opto/idealGraphPrinter.hpp"
  32 #include "opto/loopnode.hpp"
  33 #include "opto/machnode.hpp"
  34 #include "opto/opcodes.hpp"
  35 #include "opto/phaseX.hpp"
  36 #include "opto/regalloc.hpp"
  37 #include "opto/rootnode.hpp"
  38 
  39 //=============================================================================
  40 #define NODE_HASH_MINIMUM_SIZE    255
  41 //------------------------------NodeHash---------------------------------------
  42 NodeHash::NodeHash(uint est_max_size) :
  43   _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ),
  44   _a(Thread::current()->resource_area()),
  45   _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), // (Node**)_a->Amalloc(_max * sizeof(Node*)) ),
  46   _inserts(0), _insert_limit( insert_limit() ),
  47   _look_probes(0), _lookup_hits(0), _lookup_misses(0),
  48   _total_insert_probes(0), _total_inserts(0),
  49   _insert_probes(0), _grows(0) {
  50   // _sentinel must be in the current node space
  51   _sentinel = new (Compile::current()) ProjNode(NULL, TypeFunc::Control);
  52   memset(_table,0,sizeof(Node*)*_max);
  53 }
  54 
  55 //------------------------------NodeHash---------------------------------------
  56 NodeHash::NodeHash(Arena *arena, uint est_max_size) :
  57   _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ),
  58   _a(arena),
  59   _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ),
  60   _inserts(0), _insert_limit( insert_limit() ),
  61   _look_probes(0), _lookup_hits(0), _lookup_misses(0),
  62   _delete_probes(0), _delete_hits(0), _delete_misses(0),
  63   _total_insert_probes(0), _total_inserts(0),
  64   _insert_probes(0), _grows(0) {
  65   // _sentinel must be in the current node space
  66   _sentinel = new (Compile::current()) ProjNode(NULL, TypeFunc::Control);
  67   memset(_table,0,sizeof(Node*)*_max);
  68 }
  69 
  70 //------------------------------NodeHash---------------------------------------
  71 NodeHash::NodeHash(NodeHash *nh) {
  72   debug_only(_table = (Node**)badAddress);   // interact correctly w/ operator=
  73   // just copy in all the fields
  74   *this = *nh;
  75   // nh->_sentinel must be in the current node space
  76 }
  77 
  78 void NodeHash::replace_with(NodeHash *nh) {
  79   debug_only(_table = (Node**)badAddress);   // interact correctly w/ operator=
  80   // just copy in all the fields
  81   *this = *nh;
  82   // nh->_sentinel must be in the current node space
  83 }
  84 
  85 //------------------------------hash_find--------------------------------------
  86 // Find in hash table
  87 Node *NodeHash::hash_find( const Node *n ) {
  88   // ((Node*)n)->set_hash( n->hash() );
  89   uint hash = n->hash();
  90   if (hash == Node::NO_HASH) {
  91     debug_only( _lookup_misses++ );
  92     return NULL;
  93   }
  94   uint key = hash & (_max-1);
  95   uint stride = key | 0x01;
  96   debug_only( _look_probes++ );
  97   Node *k = _table[key];        // Get hashed value
  98   if( !k ) {                    // ?Miss?
  99     debug_only( _lookup_misses++ );
 100     return NULL;                // Miss!
 101   }
 102 
 103   int op = n->Opcode();
 104   uint req = n->req();
 105   while( 1 ) {                  // While probing hash table
 106     if( k->req() == req &&      // Same count of inputs
 107         k->Opcode() == op ) {   // Same Opcode
 108       for( uint i=0; i<req; i++ )
 109         if( n->in(i)!=k->in(i)) // Different inputs?
 110           goto collision;       // "goto" is a speed hack...
 111       if( n->cmp(*k) ) {        // Check for any special bits
 112         debug_only( _lookup_hits++ );
 113         return k;               // Hit!
 114       }
 115     }
 116   collision:
 117     debug_only( _look_probes++ );
 118     key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime
 119     k = _table[key];            // Get hashed value
 120     if( !k ) {                  // ?Miss?
 121       debug_only( _lookup_misses++ );
 122       return NULL;              // Miss!
 123     }
 124   }
 125   ShouldNotReachHere();
 126   return NULL;
 127 }
 128 
 129 //------------------------------hash_find_insert-------------------------------
 130 // Find in hash table, insert if not already present
 131 // Used to preserve unique entries in hash table
 132 Node *NodeHash::hash_find_insert( Node *n ) {
 133   // n->set_hash( );
 134   uint hash = n->hash();
 135   if (hash == Node::NO_HASH) {
 136     debug_only( _lookup_misses++ );
 137     return NULL;
 138   }
 139   uint key = hash & (_max-1);
 140   uint stride = key | 0x01;     // stride must be relatively prime to table siz
 141   uint first_sentinel = 0;      // replace a sentinel if seen.
 142   debug_only( _look_probes++ );
 143   Node *k = _table[key];        // Get hashed value
 144   if( !k ) {                    // ?Miss?
 145     debug_only( _lookup_misses++ );
 146     _table[key] = n;            // Insert into table!
 147     debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
 148     check_grow();               // Grow table if insert hit limit
 149     return NULL;                // Miss!
 150   }
 151   else if( k == _sentinel ) {
 152     first_sentinel = key;      // Can insert here
 153   }
 154 
 155   int op = n->Opcode();
 156   uint req = n->req();
 157   while( 1 ) {                  // While probing hash table
 158     if( k->req() == req &&      // Same count of inputs
 159         k->Opcode() == op ) {   // Same Opcode
 160       for( uint i=0; i<req; i++ )
 161         if( n->in(i)!=k->in(i)) // Different inputs?
 162           goto collision;       // "goto" is a speed hack...
 163       if( n->cmp(*k) ) {        // Check for any special bits
 164         debug_only( _lookup_hits++ );
 165         return k;               // Hit!
 166       }
 167     }
 168   collision:
 169     debug_only( _look_probes++ );
 170     key = (key + stride) & (_max-1); // Stride through table w/ relative prime
 171     k = _table[key];            // Get hashed value
 172     if( !k ) {                  // ?Miss?
 173       debug_only( _lookup_misses++ );
 174       key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel?
 175       _table[key] = n;          // Insert into table!
 176       debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
 177       check_grow();             // Grow table if insert hit limit
 178       return NULL;              // Miss!
 179     }
 180     else if( first_sentinel == 0 && k == _sentinel ) {
 181       first_sentinel = key;    // Can insert here
 182     }
 183 
 184   }
 185   ShouldNotReachHere();
 186   return NULL;
 187 }
 188 
 189 //------------------------------hash_insert------------------------------------
 190 // Insert into hash table
 191 void NodeHash::hash_insert( Node *n ) {
 192   // // "conflict" comments -- print nodes that conflict
 193   // bool conflict = false;
 194   // n->set_hash();
 195   uint hash = n->hash();
 196   if (hash == Node::NO_HASH) {
 197     return;
 198   }
 199   check_grow();
 200   uint key = hash & (_max-1);
 201   uint stride = key | 0x01;
 202 
 203   while( 1 ) {                  // While probing hash table
 204     debug_only( _insert_probes++ );
 205     Node *k = _table[key];      // Get hashed value
 206     if( !k || (k == _sentinel) ) break;       // Found a slot
 207     assert( k != n, "already inserted" );
 208     // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print("  conflict: "); k->dump(); conflict = true; }
 209     key = (key + stride) & (_max-1); // Stride through table w/ relative prime
 210   }
 211   _table[key] = n;              // Insert into table!
 212   debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
 213   // if( conflict ) { n->dump(); }
 214 }
 215 
 216 //------------------------------hash_delete------------------------------------
 217 // Replace in hash table with sentinel
 218 bool NodeHash::hash_delete( const Node *n ) {
 219   Node *k;
 220   uint hash = n->hash();
 221   if (hash == Node::NO_HASH) {
 222     debug_only( _delete_misses++ );
 223     return false;
 224   }
 225   uint key = hash & (_max-1);
 226   uint stride = key | 0x01;
 227   debug_only( uint counter = 0; );
 228   for( ; /* (k != NULL) && (k != _sentinel) */; ) {
 229     debug_only( counter++ );
 230     debug_only( _delete_probes++ );
 231     k = _table[key];            // Get hashed value
 232     if( !k ) {                  // Miss?
 233       debug_only( _delete_misses++ );
 234 #ifdef ASSERT
 235       if( VerifyOpto ) {
 236         for( uint i=0; i < _max; i++ )
 237           assert( _table[i] != n, "changed edges with rehashing" );
 238       }
 239 #endif
 240       return false;             // Miss! Not in chain
 241     }
 242     else if( n == k ) {
 243       debug_only( _delete_hits++ );
 244       _table[key] = _sentinel;  // Hit! Label as deleted entry
 245       debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table.
 246       return true;
 247     }
 248     else {
 249       // collision: move through table with prime offset
 250       key = (key + stride/*7*/) & (_max-1);
 251       assert( counter <= _insert_limit, "Cycle in hash-table");
 252     }
 253   }
 254   ShouldNotReachHere();
 255   return false;
 256 }
 257 
 258 //------------------------------round_up---------------------------------------
 259 // Round up to nearest power of 2
 260 uint NodeHash::round_up( uint x ) {
 261   x += (x>>2);                  // Add 25% slop
 262   if( x <16 ) return 16;        // Small stuff
 263   uint i=16;
 264   while( i < x ) i <<= 1;       // Double to fit
 265   return i;                     // Return hash table size
 266 }
 267 
 268 //------------------------------grow-------------------------------------------
 269 // Grow _table to next power of 2 and insert old entries
 270 void  NodeHash::grow() {
 271   // Record old state
 272   uint   old_max   = _max;
 273   Node **old_table = _table;
 274   // Construct new table with twice the space
 275   _grows++;
 276   _total_inserts       += _inserts;
 277   _total_insert_probes += _insert_probes;
 278   _inserts         = 0;
 279   _insert_probes   = 0;
 280   _max     = _max << 1;
 281   _table   = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) );
 282   memset(_table,0,sizeof(Node*)*_max);
 283   _insert_limit = insert_limit();
 284   // Insert old entries into the new table
 285   for( uint i = 0; i < old_max; i++ ) {
 286     Node *m = *old_table++;
 287     if( !m || m == _sentinel ) continue;
 288     debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table.
 289     hash_insert(m);
 290   }
 291 }
 292 
 293 //------------------------------clear------------------------------------------
 294 // Clear all entries in _table to NULL but keep storage
 295 void  NodeHash::clear() {
 296 #ifdef ASSERT
 297   // Unlock all nodes upon removal from table.
 298   for (uint i = 0; i < _max; i++) {
 299     Node* n = _table[i];
 300     if (!n || n == _sentinel)  continue;
 301     n->exit_hash_lock();
 302   }
 303 #endif
 304 
 305   memset( _table, 0, _max * sizeof(Node*) );
 306 }
 307 
 308 //-----------------------remove_useless_nodes----------------------------------
 309 // Remove useless nodes from value table,
 310 // implementation does not depend on hash function
 311 void NodeHash::remove_useless_nodes(VectorSet &useful) {
 312 
 313   // Dead nodes in the hash table inherited from GVN should not replace
 314   // existing nodes, remove dead nodes.
 315   uint max = size();
 316   Node *sentinel_node = sentinel();
 317   for( uint i = 0; i < max; ++i ) {
 318     Node *n = at(i);
 319     if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) {
 320       debug_only(n->exit_hash_lock()); // Unlock the node when removed
 321       _table[i] = sentinel_node;       // Replace with placeholder
 322     }
 323   }
 324 }
 325 
 326 
 327 void NodeHash::check_no_speculative_types() {
 328 #ifdef ASSERT
 329   uint max = size();
 330   Node *sentinel_node = sentinel();
 331   for (uint i = 0; i < max; ++i) {
 332     Node *n = at(i);
 333     if(n != NULL && n != sentinel_node && n->is_Type()) {
 334       TypeNode* tn = n->as_Type();
 335       const Type* t = tn->type();
 336       const Type* t_no_spec = t->remove_speculative();
 337       assert(t == t_no_spec, "dead node in hash table or missed node during speculative cleanup");
 338     }
 339   }
 340 #endif
 341 }
 342 
 343 #ifndef PRODUCT
 344 //------------------------------dump-------------------------------------------
 345 // Dump statistics for the hash table
 346 void NodeHash::dump() {
 347   _total_inserts       += _inserts;
 348   _total_insert_probes += _insert_probes;
 349   if (PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0)) {
 350     if (WizardMode) {
 351       for (uint i=0; i<_max; i++) {
 352         if (_table[i])
 353           tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx);
 354       }
 355     }
 356     tty->print("\nGVN Hash stats:  %d grows to %d max_size\n", _grows, _max);
 357     tty->print("  %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0);
 358     tty->print("  %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses));
 359     tty->print("  %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts);
 360     // sentinels increase lookup cost, but not insert cost
 361     assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function");
 362     assert( _inserts+(_inserts>>3) < _max, "table too full" );
 363     assert( _inserts*3+100 >= _insert_probes, "bad hash function" );
 364   }
 365 }
 366 
 367 Node *NodeHash::find_index(uint idx) { // For debugging
 368   // Find an entry by its index value
 369   for( uint i = 0; i < _max; i++ ) {
 370     Node *m = _table[i];
 371     if( !m || m == _sentinel ) continue;
 372     if( m->_idx == (uint)idx ) return m;
 373   }
 374   return NULL;
 375 }
 376 #endif
 377 
 378 #ifdef ASSERT
 379 NodeHash::~NodeHash() {
 380   // Unlock all nodes upon destruction of table.
 381   if (_table != (Node**)badAddress)  clear();
 382 }
 383 
 384 void NodeHash::operator=(const NodeHash& nh) {
 385   // Unlock all nodes upon replacement of table.
 386   if (&nh == this)  return;
 387   if (_table != (Node**)badAddress)  clear();
 388   memcpy(this, &nh, sizeof(*this));
 389   // Do not increment hash_lock counts again.
 390   // Instead, be sure we never again use the source table.
 391   ((NodeHash*)&nh)->_table = (Node**)badAddress;
 392 }
 393 
 394 
 395 #endif
 396 
 397 
 398 //=============================================================================
 399 //------------------------------PhaseRemoveUseless-----------------------------
 400 // 1) Use a breadthfirst walk to collect useful nodes reachable from root.
 401 PhaseRemoveUseless::PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist ) : Phase(Remove_Useless),
 402   _useful(Thread::current()->resource_area()) {
 403 
 404   // Implementation requires 'UseLoopSafepoints == true' and an edge from root
 405   // to each SafePointNode at a backward branch.  Inserted in add_safepoint().
 406   if( !UseLoopSafepoints || !OptoRemoveUseless ) return;
 407 
 408   // Identify nodes that are reachable from below, useful.
 409   C->identify_useful_nodes(_useful);
 410   // Update dead node list
 411   C->update_dead_node_list(_useful);
 412 
 413   // Remove all useless nodes from PhaseValues' recorded types
 414   // Must be done before disconnecting nodes to preserve hash-table-invariant
 415   gvn->remove_useless_nodes(_useful.member_set());
 416 
 417   // Remove all useless nodes from future worklist
 418   worklist->remove_useless_nodes(_useful.member_set());
 419 
 420   // Disconnect 'useless' nodes that are adjacent to useful nodes
 421   C->remove_useless_nodes(_useful);
 422 
 423   // Remove edges from "root" to each SafePoint at a backward branch.
 424   // They were inserted during parsing (see add_safepoint()) to make infinite
 425   // loops without calls or exceptions visible to root, i.e., useful.
 426   Node *root = C->root();
 427   if( root != NULL ) {
 428     for( uint i = root->req(); i < root->len(); ++i ) {
 429       Node *n = root->in(i);
 430       if( n != NULL && n->is_SafePoint() ) {
 431         root->rm_prec(i);
 432         --i;
 433       }
 434     }
 435   }
 436 }
 437 
 438 
 439 //=============================================================================
 440 //------------------------------PhaseTransform---------------------------------
 441 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum),
 442   _arena(Thread::current()->resource_area()),
 443   _nodes(_arena),
 444   _types(_arena)
 445 {
 446   init_con_caches();
 447 #ifndef PRODUCT
 448   clear_progress();
 449   clear_transforms();
 450   set_allow_progress(true);
 451 #endif
 452   // Force allocation for currently existing nodes
 453   _types.map(C->unique(), NULL);
 454 }
 455 
 456 //------------------------------PhaseTransform---------------------------------
 457 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum),
 458   _arena(arena),
 459   _nodes(arena),
 460   _types(arena)
 461 {
 462   init_con_caches();
 463 #ifndef PRODUCT
 464   clear_progress();
 465   clear_transforms();
 466   set_allow_progress(true);
 467 #endif
 468   // Force allocation for currently existing nodes
 469   _types.map(C->unique(), NULL);
 470 }
 471 
 472 //------------------------------PhaseTransform---------------------------------
 473 // Initialize with previously generated type information
 474 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum),
 475   _arena(pt->_arena),
 476   _nodes(pt->_nodes),
 477   _types(pt->_types)
 478 {
 479   init_con_caches();
 480 #ifndef PRODUCT
 481   clear_progress();
 482   clear_transforms();
 483   set_allow_progress(true);
 484 #endif
 485 }
 486 
 487 void PhaseTransform::init_con_caches() {
 488   memset(_icons,0,sizeof(_icons));
 489   memset(_lcons,0,sizeof(_lcons));
 490   memset(_zcons,0,sizeof(_zcons));
 491 }
 492 
 493 
 494 //--------------------------------find_int_type--------------------------------
 495 const TypeInt* PhaseTransform::find_int_type(Node* n) {
 496   if (n == NULL)  return NULL;
 497   // Call type_or_null(n) to determine node's type since we might be in
 498   // parse phase and call n->Value() may return wrong type.
 499   // (For example, a phi node at the beginning of loop parsing is not ready.)
 500   const Type* t = type_or_null(n);
 501   if (t == NULL)  return NULL;
 502   return t->isa_int();
 503 }
 504 
 505 
 506 //-------------------------------find_long_type--------------------------------
 507 const TypeLong* PhaseTransform::find_long_type(Node* n) {
 508   if (n == NULL)  return NULL;
 509   // (See comment above on type_or_null.)
 510   const Type* t = type_or_null(n);
 511   if (t == NULL)  return NULL;
 512   return t->isa_long();
 513 }
 514 
 515 
 516 #ifndef PRODUCT
 517 void PhaseTransform::dump_old2new_map() const {
 518   _nodes.dump();
 519 }
 520 
 521 void PhaseTransform::dump_new( uint nidx ) const {
 522   for( uint i=0; i<_nodes.Size(); i++ )
 523     if( _nodes[i] && _nodes[i]->_idx == nidx ) {
 524       _nodes[i]->dump();
 525       tty->cr();
 526       tty->print_cr("Old index= %d",i);
 527       return;
 528     }
 529   tty->print_cr("Node %d not found in the new indices", nidx);
 530 }
 531 
 532 //------------------------------dump_types-------------------------------------
 533 void PhaseTransform::dump_types( ) const {
 534   _types.dump();
 535 }
 536 
 537 //------------------------------dump_nodes_and_types---------------------------
 538 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) {
 539   VectorSet visited(Thread::current()->resource_area());
 540   dump_nodes_and_types_recur( root, depth, only_ctrl, visited );
 541 }
 542 
 543 //------------------------------dump_nodes_and_types_recur---------------------
 544 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) {
 545   if( !n ) return;
 546   if( depth == 0 ) return;
 547   if( visited.test_set(n->_idx) ) return;
 548   for( uint i=0; i<n->len(); i++ ) {
 549     if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue;
 550     dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited );
 551   }
 552   n->dump();
 553   if (type_or_null(n) != NULL) {
 554     tty->print("      "); type(n)->dump(); tty->cr();
 555   }
 556 }
 557 
 558 #endif
 559 
 560 
 561 //=============================================================================
 562 //------------------------------PhaseValues------------------------------------
 563 // Set minimum table size to "255"
 564 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) {
 565   NOT_PRODUCT( clear_new_values(); )
 566 }
 567 
 568 //------------------------------PhaseValues------------------------------------
 569 // Set minimum table size to "255"
 570 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ),
 571   _table(&ptv->_table) {
 572   NOT_PRODUCT( clear_new_values(); )
 573 }
 574 
 575 //------------------------------PhaseValues------------------------------------
 576 // Used by +VerifyOpto.  Clear out hash table but copy _types array.
 577 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ),
 578   _table(ptv->arena(),ptv->_table.size()) {
 579   NOT_PRODUCT( clear_new_values(); )
 580 }
 581 
 582 //------------------------------~PhaseValues-----------------------------------
 583 #ifndef PRODUCT
 584 PhaseValues::~PhaseValues() {
 585   _table.dump();
 586 
 587   // Statistics for value progress and efficiency
 588   if( PrintCompilation && Verbose && WizardMode ) {
 589     tty->print("\n%sValues: %d nodes ---> %d/%d (%d)",
 590       is_IterGVN() ? "Iter" : "    ", C->unique(), made_progress(), made_transforms(), made_new_values());
 591     if( made_transforms() != 0 ) {
 592       tty->print_cr("  ratio %f", made_progress()/(float)made_transforms() );
 593     } else {
 594       tty->cr();
 595     }
 596   }
 597 }
 598 #endif
 599 
 600 //------------------------------makecon----------------------------------------
 601 ConNode* PhaseTransform::makecon(const Type *t) {
 602   assert(t->singleton(), "must be a constant");
 603   assert(!t->empty() || t == Type::TOP, "must not be vacuous range");
 604   switch (t->base()) {  // fast paths
 605   case Type::Half:
 606   case Type::Top:  return (ConNode*) C->top();
 607   case Type::Int:  return intcon( t->is_int()->get_con() );
 608   case Type::Long: return longcon( t->is_long()->get_con() );
 609   }
 610   if (t->is_zero_type())
 611     return zerocon(t->basic_type());
 612   return uncached_makecon(t);
 613 }
 614 
 615 //--------------------------uncached_makecon-----------------------------------
 616 // Make an idealized constant - one of ConINode, ConPNode, etc.
 617 ConNode* PhaseValues::uncached_makecon(const Type *t) {
 618   assert(t->singleton(), "must be a constant");
 619   ConNode* x = ConNode::make(C, t);
 620   ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering
 621   if (k == NULL) {
 622     set_type(x, t);             // Missed, provide type mapping
 623     GrowableArray<Node_Notes*>* nna = C->node_note_array();
 624     if (nna != NULL) {
 625       Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true);
 626       loc->clear(); // do not put debug info on constants
 627     }
 628   } else {
 629     x->destruct();              // Hit, destroy duplicate constant
 630     x = k;                      // use existing constant
 631   }
 632   return x;
 633 }
 634 
 635 //------------------------------intcon-----------------------------------------
 636 // Fast integer constant.  Same as "transform(new ConINode(TypeInt::make(i)))"
 637 ConINode* PhaseTransform::intcon(int i) {
 638   // Small integer?  Check cache! Check that cached node is not dead
 639   if (i >= _icon_min && i <= _icon_max) {
 640     ConINode* icon = _icons[i-_icon_min];
 641     if (icon != NULL && icon->in(TypeFunc::Control) != NULL)
 642       return icon;
 643   }
 644   ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i));
 645   assert(icon->is_Con(), "");
 646   if (i >= _icon_min && i <= _icon_max)
 647     _icons[i-_icon_min] = icon;   // Cache small integers
 648   return icon;
 649 }
 650 
 651 //------------------------------longcon----------------------------------------
 652 // Fast long constant.
 653 ConLNode* PhaseTransform::longcon(jlong l) {
 654   // Small integer?  Check cache! Check that cached node is not dead
 655   if (l >= _lcon_min && l <= _lcon_max) {
 656     ConLNode* lcon = _lcons[l-_lcon_min];
 657     if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL)
 658       return lcon;
 659   }
 660   ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l));
 661   assert(lcon->is_Con(), "");
 662   if (l >= _lcon_min && l <= _lcon_max)
 663     _lcons[l-_lcon_min] = lcon;      // Cache small integers
 664   return lcon;
 665 }
 666 
 667 //------------------------------zerocon-----------------------------------------
 668 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))"
 669 ConNode* PhaseTransform::zerocon(BasicType bt) {
 670   assert((uint)bt <= _zcon_max, "domain check");
 671   ConNode* zcon = _zcons[bt];
 672   if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL)
 673     return zcon;
 674   zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt));
 675   _zcons[bt] = zcon;
 676   return zcon;
 677 }
 678 
 679 
 680 
 681 //=============================================================================
 682 //------------------------------transform--------------------------------------
 683 // Return a node which computes the same function as this node, but in a
 684 // faster or cheaper fashion.
 685 Node *PhaseGVN::transform( Node *n ) {
 686   return transform_no_reclaim(n);
 687 }
 688 
 689 //------------------------------transform--------------------------------------
 690 // Return a node which computes the same function as this node, but
 691 // in a faster or cheaper fashion.
 692 Node *PhaseGVN::transform_no_reclaim( Node *n ) {
 693   NOT_PRODUCT( set_transforms(); )
 694 
 695   // Apply the Ideal call in a loop until it no longer applies
 696   Node *k = n;
 697   NOT_PRODUCT( uint loop_count = 0; )
 698   while( 1 ) {
 699     Node *i = k->Ideal(this, /*can_reshape=*/false);
 700     if( !i ) break;
 701     assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" );
 702     k = i;
 703     assert(loop_count++ < K, "infinite loop in PhaseGVN::transform");
 704   }
 705   NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } )
 706 
 707 
 708   // If brand new node, make space in type array.
 709   ensure_type_or_null(k);
 710 
 711   // Since I just called 'Value' to compute the set of run-time values
 712   // for this Node, and 'Value' is non-local (and therefore expensive) I'll
 713   // cache Value.  Later requests for the local phase->type of this Node can
 714   // use the cached Value instead of suffering with 'bottom_type'.
 715   const Type *t = k->Value(this); // Get runtime Value set
 716   assert(t != NULL, "value sanity");
 717   if (type_or_null(k) != t) {
 718 #ifndef PRODUCT
 719     // Do not count initial visit to node as a transformation
 720     if (type_or_null(k) == NULL) {
 721       inc_new_values();
 722       set_progress();
 723     }
 724 #endif
 725     set_type(k, t);
 726     // If k is a TypeNode, capture any more-precise type permanently into Node
 727     k->raise_bottom_type(t);
 728   }
 729 
 730   if( t->singleton() && !k->is_Con() ) {
 731     NOT_PRODUCT( set_progress(); )
 732     return makecon(t);          // Turn into a constant
 733   }
 734 
 735   // Now check for Identities
 736   Node *i = k->Identity(this);  // Look for a nearby replacement
 737   if( i != k ) {                // Found? Return replacement!
 738     NOT_PRODUCT( set_progress(); )
 739     return i;
 740   }
 741 
 742   // Global Value Numbering
 743   i = hash_find_insert(k);      // Insert if new
 744   if( i && (i != k) ) {
 745     // Return the pre-existing node
 746     NOT_PRODUCT( set_progress(); )
 747     return i;
 748   }
 749 
 750   // Return Idealized original
 751   return k;
 752 }
 753 
 754 #ifdef ASSERT
 755 //------------------------------dead_loop_check--------------------------------
 756 // Check for a simple dead loop when a data node references itself directly
 757 // or through an other data node excluding cons and phis.
 758 void PhaseGVN::dead_loop_check( Node *n ) {
 759   // Phi may reference itself in a loop
 760   if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) {
 761     // Do 2 levels check and only data inputs.
 762     bool no_dead_loop = true;
 763     uint cnt = n->req();
 764     for (uint i = 1; i < cnt && no_dead_loop; i++) {
 765       Node *in = n->in(i);
 766       if (in == n) {
 767         no_dead_loop = false;
 768       } else if (in != NULL && !in->is_dead_loop_safe()) {
 769         uint icnt = in->req();
 770         for (uint j = 1; j < icnt && no_dead_loop; j++) {
 771           if (in->in(j) == n || in->in(j) == in)
 772             no_dead_loop = false;
 773         }
 774       }
 775     }
 776     if (!no_dead_loop) n->dump(3);
 777     assert(no_dead_loop, "dead loop detected");
 778   }
 779 }
 780 #endif
 781 
 782 //=============================================================================
 783 //------------------------------PhaseIterGVN-----------------------------------
 784 // Initialize hash table to fresh and clean for +VerifyOpto
 785 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ),
 786                                                                       _stack(C->unique() >> 1),
 787                                                                       _delay_transform(false) {
 788 }
 789 
 790 //------------------------------PhaseIterGVN-----------------------------------
 791 // Initialize with previous PhaseIterGVN info; used by PhaseCCP
 792 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn),
 793                                                    _worklist( igvn->_worklist ),
 794                                                    _stack( igvn->_stack ),
 795                                                    _delay_transform(igvn->_delay_transform)
 796 {
 797 }
 798 
 799 //------------------------------PhaseIterGVN-----------------------------------
 800 // Initialize with previous PhaseGVN info from Parser
 801 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn),
 802                                               _worklist(*C->for_igvn()),
 803                                               _stack(C->unique() >> 1),




 804                                               _delay_transform(false)
 805 {
 806   uint max;
 807 
 808   // Dead nodes in the hash table inherited from GVN were not treated as
 809   // roots during def-use info creation; hence they represent an invisible
 810   // use.  Clear them out.
 811   max = _table.size();
 812   for( uint i = 0; i < max; ++i ) {
 813     Node *n = _table.at(i);
 814     if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) {
 815       if( n->is_top() ) continue;
 816       assert( false, "Parse::remove_useless_nodes missed this node");
 817       hash_delete(n);
 818     }
 819   }
 820 
 821   // Any Phis or Regions on the worklist probably had uses that could not
 822   // make more progress because the uses were made while the Phis and Regions
 823   // were in half-built states.  Put all uses of Phis and Regions on worklist.
 824   max = _worklist.size();
 825   for( uint j = 0; j < max; j++ ) {
 826     Node *n = _worklist.at(j);
 827     uint uop = n->Opcode();
 828     if( uop == Op_Phi || uop == Op_Region ||
 829         n->is_Type() ||
 830         n->is_Mem() )
 831       add_users_to_worklist(n);
 832   }
 833 }
 834 
 835 
 836 #ifndef PRODUCT
 837 void PhaseIterGVN::verify_step(Node* n) {
 838   _verify_window[_verify_counter % _verify_window_size] = n;
 839   ++_verify_counter;
 840   ResourceMark rm;
 841   ResourceArea *area = Thread::current()->resource_area();
 842   VectorSet old_space(area), new_space(area);
 843   if (C->unique() < 1000 ||
 844       0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) {
 845     ++_verify_full_passes;
 846     Node::verify_recur(C->root(), -1, old_space, new_space);
 847   }
 848   const int verify_depth = 4;
 849   for ( int i = 0; i < _verify_window_size; i++ ) {
 850     Node* n = _verify_window[i];
 851     if ( n == NULL )  continue;
 852     if( n->in(0) == NodeSentinel ) {  // xform_idom
 853       _verify_window[i] = n->in(1);
 854       --i; continue;
 855     }
 856     // Typical fanout is 1-2, so this call visits about 6 nodes.
 857     Node::verify_recur(n, verify_depth, old_space, new_space);
 858   }
 859 }
 860 #endif
 861 
 862 
 863 //------------------------------init_worklist----------------------------------
 864 // Initialize worklist for each node.
 865 void PhaseIterGVN::init_worklist( Node *n ) {
 866   if( _worklist.member(n) ) return;
 867   _worklist.push(n);
 868   uint cnt = n->req();
 869   for( uint i =0 ; i < cnt; i++ ) {
 870     Node *m = n->in(i);
 871     if( m ) init_worklist(m);
 872   }
 873 }
 874 
 875 //------------------------------optimize---------------------------------------
 876 void PhaseIterGVN::optimize() {
 877   debug_only(uint num_processed  = 0;);
 878 #ifndef PRODUCT
 879   {
 880     _verify_counter = 0;
 881     _verify_full_passes = 0;
 882     for ( int i = 0; i < _verify_window_size; i++ ) {
 883       _verify_window[i] = NULL;
 884     }
 885   }
 886 #endif
 887 
 888 #ifdef ASSERT
 889   Node* prev = NULL;
 890   uint rep_cnt = 0;
 891 #endif
 892   uint loop_count = 0;
 893 
 894   // Pull from worklist; transform node;
 895   // If node has changed: update edge info and put uses on worklist.
 896   while( _worklist.size() ) {
 897     if (C->check_node_count(NodeLimitFudgeFactor * 2,
 898                             "out of nodes optimizing method")) {
 899       return;
 900     }
 901     Node *n  = _worklist.pop();
 902     if (++loop_count >= K * C->live_nodes()) {
 903       debug_only(n->dump(4);)
 904       assert(false, "infinite loop in PhaseIterGVN::optimize");
 905       C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize");
 906       return;
 907     }
 908 #ifdef ASSERT
 909     if (n == prev) {
 910       if (++rep_cnt > 3) {
 911         n->dump(4);
 912         assert(false, "loop in Ideal transformation");
 913       }
 914     } else {
 915       rep_cnt = 0;
 916     }
 917     prev = n;
 918 #endif
 919     if (TraceIterativeGVN && Verbose) {
 920       tty->print("  Pop ");
 921       NOT_PRODUCT( n->dump(); )
 922       debug_only(if( (num_processed++ % 100) == 0 ) _worklist.print_set();)
 923     }
 924 
 925     if (n->outcnt() != 0) {
 926 
 927 #ifndef PRODUCT
 928       uint wlsize = _worklist.size();
 929       const Type* oldtype = type_or_null(n);
 930 #endif //PRODUCT
 931 
 932       Node *nn = transform_old(n);
 933 
 934 #ifndef PRODUCT
 935       if (TraceIterativeGVN) {
 936         const Type* newtype = type_or_null(n);
 937         if (nn != n) {
 938           // print old node
 939           tty->print("< ");
 940           if (oldtype != newtype && oldtype != NULL) {
 941             oldtype->dump();
 942           }
 943           do { tty->print("\t"); } while (tty->position() < 16);
 944           tty->print("<");
 945           n->dump();
 946         }
 947         if (oldtype != newtype || nn != n) {
 948           // print new node and/or new type
 949           if (oldtype == NULL) {
 950             tty->print("* ");
 951           } else if (nn != n) {
 952             tty->print("> ");
 953           } else {
 954             tty->print("= ");
 955           }
 956           if (newtype == NULL) {
 957             tty->print("null");
 958           } else {
 959             newtype->dump();
 960           }
 961           do { tty->print("\t"); } while (tty->position() < 16);
 962           nn->dump();
 963         }
 964         if (Verbose && wlsize < _worklist.size()) {
 965           tty->print("  Push {");
 966           while (wlsize != _worklist.size()) {
 967             Node* pushed = _worklist.at(wlsize++);
 968             tty->print(" %d", pushed->_idx);
 969           }
 970           tty->print_cr(" }");
 971         }
 972       }
 973       if( VerifyIterativeGVN && nn != n ) {
 974         verify_step((Node*) NULL);  // ignore n, it might be subsumed
 975       }
 976 #endif
 977     } else if (!n->is_top()) {
 978       remove_dead_node(n);
 979     }
 980   }
 981 
 982 #ifndef PRODUCT
 983   C->verify_graph_edges();
 984   if( VerifyOpto && allow_progress() ) {
 985     // Must turn off allow_progress to enable assert and break recursion
 986     C->root()->verify();
 987     { // Check if any progress was missed using IterGVN
 988       // Def-Use info enables transformations not attempted in wash-pass
 989       // e.g. Region/Phi cleanup, ...
 990       // Null-check elision -- may not have reached fixpoint
 991       //                       do not propagate to dominated nodes
 992       ResourceMark rm;
 993       PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean!
 994       // Fill worklist completely
 995       igvn2.init_worklist(C->root());
 996 
 997       igvn2.set_allow_progress(false);
 998       igvn2.optimize();
 999       igvn2.set_allow_progress(true);
1000     }
1001   }
1002   if ( VerifyIterativeGVN && PrintOpto ) {
1003     if ( _verify_counter == _verify_full_passes )
1004       tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes",
1005                     (int) _verify_full_passes);
1006     else
1007       tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes",
1008                   (int) _verify_counter, (int) _verify_full_passes);
1009   }
1010 #endif
1011 }
1012 
1013 
1014 //------------------register_new_node_with_optimizer---------------------------
1015 // Register a new node with the optimizer.  Update the types array, the def-use
1016 // info.  Put on worklist.
1017 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) {
1018   set_type_bottom(n);
1019   _worklist.push(n);
1020   if (orig != NULL)  C->copy_node_notes_to(n, orig);
1021   return n;
1022 }
1023 
1024 //------------------------------transform--------------------------------------
1025 // Non-recursive: idealize Node 'n' with respect to its inputs and its value
1026 Node *PhaseIterGVN::transform( Node *n ) {
1027   if (_delay_transform) {
1028     // Register the node but don't optimize for now
1029     register_new_node_with_optimizer(n);
1030     return n;
1031   }
1032 
1033   // If brand new node, make space in type array, and give it a type.
1034   ensure_type_or_null(n);
1035   if (type_or_null(n) == NULL) {
1036     set_type_bottom(n);
1037   }
1038 
1039   return transform_old(n);
1040 }
1041 
1042 //------------------------------transform_old----------------------------------
1043 Node *PhaseIterGVN::transform_old( Node *n ) {
1044 #ifndef PRODUCT
1045   debug_only(uint loop_count = 0;);
1046   set_transforms();
1047 #endif
1048   // Remove 'n' from hash table in case it gets modified
1049   _table.hash_delete(n);
1050   if( VerifyIterativeGVN ) {
1051    assert( !_table.find_index(n->_idx), "found duplicate entry in table");
1052   }
1053 
1054   // Apply the Ideal call in a loop until it no longer applies
1055   Node *k = n;
1056   DEBUG_ONLY(dead_loop_check(k);)
1057   DEBUG_ONLY(bool is_new = (k->outcnt() == 0);)
1058   Node *i = k->Ideal(this, /*can_reshape=*/true);
1059   assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes");
1060 #ifndef PRODUCT
1061   if( VerifyIterativeGVN )
1062     verify_step(k);
1063   if( i && VerifyOpto ) {
1064     if( !allow_progress() ) {
1065       if (i->is_Add() && i->outcnt() == 1) {
1066         // Switched input to left side because this is the only use
1067       } else if( i->is_If() && (i->in(0) == NULL) ) {
1068         // This IF is dead because it is dominated by an equivalent IF When
1069         // dominating if changed, info is not propagated sparsely to 'this'
1070         // Propagating this info further will spuriously identify other
1071         // progress.
1072         return i;
1073       } else
1074         set_progress();
1075     } else
1076       set_progress();
1077   }
1078 #endif
1079 
1080   while( i ) {
1081 #ifndef PRODUCT
1082     debug_only( if( loop_count >= K ) i->dump(4); )
1083     assert(loop_count < K, "infinite loop in PhaseIterGVN::transform");
1084     debug_only( loop_count++; )
1085 #endif
1086     assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes");
1087     // Made a change; put users of original Node on worklist
1088     add_users_to_worklist( k );
1089     // Replacing root of transform tree?
1090     if( k != i ) {
1091       // Make users of old Node now use new.
1092       subsume_node( k, i );
1093       k = i;
1094     }
1095     DEBUG_ONLY(dead_loop_check(k);)
1096     // Try idealizing again
1097     DEBUG_ONLY(is_new = (k->outcnt() == 0);)
1098     i = k->Ideal(this, /*can_reshape=*/true);
1099     assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes");
1100 #ifndef PRODUCT
1101     if( VerifyIterativeGVN )
1102       verify_step(k);
1103     if( i && VerifyOpto ) set_progress();
1104 #endif
1105   }
1106 
1107   // If brand new node, make space in type array.
1108   ensure_type_or_null(k);
1109 
1110   // See what kind of values 'k' takes on at runtime
1111   const Type *t = k->Value(this);
1112   assert(t != NULL, "value sanity");
1113 
1114   // Since I just called 'Value' to compute the set of run-time values
1115   // for this Node, and 'Value' is non-local (and therefore expensive) I'll
1116   // cache Value.  Later requests for the local phase->type of this Node can
1117   // use the cached Value instead of suffering with 'bottom_type'.
1118   if (t != type_or_null(k)) {
1119     NOT_PRODUCT( set_progress(); )
1120     NOT_PRODUCT( inc_new_values();)
1121     set_type(k, t);
1122     // If k is a TypeNode, capture any more-precise type permanently into Node
1123     k->raise_bottom_type(t);
1124     // Move users of node to worklist
1125     add_users_to_worklist( k );
1126   }
1127 
1128   // If 'k' computes a constant, replace it with a constant
1129   if( t->singleton() && !k->is_Con() ) {
1130     NOT_PRODUCT( set_progress(); )
1131     Node *con = makecon(t);     // Make a constant
1132     add_users_to_worklist( k );
1133     subsume_node( k, con );     // Everybody using k now uses con
1134     return con;
1135   }
1136 
1137   // Now check for Identities
1138   i = k->Identity(this);        // Look for a nearby replacement
1139   if( i != k ) {                // Found? Return replacement!
1140     NOT_PRODUCT( set_progress(); )
1141     add_users_to_worklist( k );
1142     subsume_node( k, i );       // Everybody using k now uses i
1143     return i;
1144   }
1145 
1146   // Global Value Numbering
1147   i = hash_find_insert(k);      // Check for pre-existing node
1148   if( i && (i != k) ) {
1149     // Return the pre-existing node if it isn't dead
1150     NOT_PRODUCT( set_progress(); )
1151     add_users_to_worklist( k );
1152     subsume_node( k, i );       // Everybody using k now uses i
1153     return i;
1154   }
1155 
1156   // Return Idealized original
1157   return k;
1158 }
1159 
1160 //---------------------------------saturate------------------------------------
1161 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type,
1162                                    const Type* limit_type) const {
1163   return new_type->narrow(old_type);
1164 }
1165 
1166 //------------------------------remove_globally_dead_node----------------------
1167 // Kill a globally dead Node.  All uses are also globally dead and are
1168 // aggressively trimmed.
1169 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) {
1170   enum DeleteProgress {
1171     PROCESS_INPUTS,
1172     PROCESS_OUTPUTS
1173   };
1174   assert(_stack.is_empty(), "not empty");
1175   _stack.push(dead, PROCESS_INPUTS);
1176 
1177   while (_stack.is_nonempty()) {
1178     dead = _stack.node();
1179     uint progress_state = _stack.index();
1180     assert(dead != C->root(), "killing root, eh?");
1181     assert(!dead->is_top(), "add check for top when pushing");
1182     NOT_PRODUCT( set_progress(); )
1183     if (progress_state == PROCESS_INPUTS) {
1184       // After following inputs, continue to outputs
1185       _stack.set_index(PROCESS_OUTPUTS);
1186       if (!dead->is_Con()) { // Don't kill cons but uses
1187         bool recurse = false;
1188         // Remove from hash table
1189         _table.hash_delete( dead );
1190         // Smash all inputs to 'dead', isolating him completely
1191         for (uint i = 0; i < dead->req(); i++) {
1192           Node *in = dead->in(i);
1193           if (in != NULL && in != C->top()) {  // Points to something?
1194             int nrep = dead->replace_edge(in, NULL);  // Kill edges
1195             assert((nrep > 0), "sanity");
1196             if (in->outcnt() == 0) { // Made input go dead?
1197               _stack.push(in, PROCESS_INPUTS); // Recursively remove
1198               recurse = true;
1199             } else if (in->outcnt() == 1 &&
1200                        in->has_special_unique_user()) {
1201               _worklist.push(in->unique_out());
1202             } else if (in->outcnt() <= 2 && dead->is_Phi()) {
1203               if (in->Opcode() == Op_Region) {
1204                 _worklist.push(in);
1205               } else if (in->is_Store()) {
1206                 DUIterator_Fast imax, i = in->fast_outs(imax);
1207                 _worklist.push(in->fast_out(i));
1208                 i++;
1209                 if (in->outcnt() == 2) {
1210                   _worklist.push(in->fast_out(i));
1211                   i++;
1212                 }
1213                 assert(!(i < imax), "sanity");
1214               }
1215             }
1216             if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory &&
1217                 in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) {
1218               // A Load that directly follows an InitializeNode is
1219               // going away. The Stores that follow are candidates
1220               // again to be captured by the InitializeNode.
1221               for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) {
1222                 Node *n = in->fast_out(j);
1223                 if (n->is_Store()) {
1224                   _worklist.push(n);
1225                 }
1226               }
1227             }
1228           } // if (in != NULL && in != C->top())
1229         } // for (uint i = 0; i < dead->req(); i++)
1230         if (recurse) {
1231           continue;
1232         }
1233       } // if (!dead->is_Con())
1234     } // if (progress_state == PROCESS_INPUTS)
1235 
1236     // Aggressively kill globally dead uses
1237     // (Rather than pushing all the outs at once, we push one at a time,
1238     // plus the parent to resume later, because of the indefinite number
1239     // of edge deletions per loop trip.)
1240     if (dead->outcnt() > 0) {
1241       // Recursively remove output edges
1242       _stack.push(dead->raw_out(0), PROCESS_INPUTS);
1243     } else {
1244       // Finished disconnecting all input and output edges.
1245       _stack.pop();
1246       // Remove dead node from iterative worklist
1247       _worklist.remove(dead);
1248       // Constant node that has no out-edges and has only one in-edge from
1249       // root is usually dead. However, sometimes reshaping walk makes
1250       // it reachable by adding use edges. So, we will NOT count Con nodes
1251       // as dead to be conservative about the dead node count at any
1252       // given time.
1253       if (!dead->is_Con()) {
1254         C->record_dead_node(dead->_idx);
1255       }
1256       if (dead->is_macro()) {
1257         C->remove_macro_node(dead);
1258       }
1259       if (dead->is_expensive()) {
1260         C->remove_expensive_node(dead);
1261       }
1262     }
1263   } // while (_stack.is_nonempty())
1264 }
1265 
1266 //------------------------------subsume_node-----------------------------------
1267 // Remove users from node 'old' and add them to node 'nn'.
1268 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) {
1269   assert( old != hash_find(old), "should already been removed" );
1270   assert( old != C->top(), "cannot subsume top node");
1271   // Copy debug or profile information to the new version:
1272   C->copy_node_notes_to(nn, old);
1273   // Move users of node 'old' to node 'nn'
1274   for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) {
1275     Node* use = old->last_out(i);  // for each use...
1276     // use might need re-hashing (but it won't if it's a new node)
1277     bool is_in_table = _table.hash_delete( use );
1278     // Update use-def info as well
1279     // We remove all occurrences of old within use->in,
1280     // so as to avoid rehashing any node more than once.
1281     // The hash table probe swamps any outer loop overhead.
1282     uint num_edges = 0;
1283     for (uint jmax = use->len(), j = 0; j < jmax; j++) {
1284       if (use->in(j) == old) {
1285         use->set_req(j, nn);
1286         ++num_edges;
1287       }
1288     }
1289     // Insert into GVN hash table if unique
1290     // If a duplicate, 'use' will be cleaned up when pulled off worklist
1291     if( is_in_table ) {
1292       hash_find_insert(use);
1293     }
1294     i -= num_edges;    // we deleted 1 or more copies of this edge
1295   }
1296 
1297   // Smash all inputs to 'old', isolating him completely
1298   Node *temp = new (C) Node(1);
1299   temp->init_req(0,nn);     // Add a use to nn to prevent him from dying
1300   remove_dead_node( old );
1301   temp->del_req(0);         // Yank bogus edge
1302 #ifndef PRODUCT
1303   if( VerifyIterativeGVN ) {
1304     for ( int i = 0; i < _verify_window_size; i++ ) {
1305       if ( _verify_window[i] == old )
1306         _verify_window[i] = nn;
1307     }
1308   }
1309 #endif
1310   _worklist.remove(temp);   // this can be necessary
1311   temp->destruct();         // reuse the _idx of this little guy
1312 }
1313 
1314 //------------------------------add_users_to_worklist--------------------------
1315 void PhaseIterGVN::add_users_to_worklist0( Node *n ) {
1316   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1317     _worklist.push(n->fast_out(i));  // Push on worklist
1318   }
1319 }
1320 
1321 void PhaseIterGVN::add_users_to_worklist( Node *n ) {
1322   add_users_to_worklist0(n);
1323 
1324   // Move users of node to worklist
1325   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1326     Node* use = n->fast_out(i); // Get use
1327 
1328     if( use->is_Multi() ||      // Multi-definer?  Push projs on worklist
1329         use->is_Store() )       // Enable store/load same address
1330       add_users_to_worklist0(use);
1331 
1332     // If we changed the receiver type to a call, we need to revisit
1333     // the Catch following the call.  It's looking for a non-NULL
1334     // receiver to know when to enable the regular fall-through path
1335     // in addition to the NullPtrException path.
1336     if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) {
1337       Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control);
1338       if (p != NULL) {
1339         add_users_to_worklist0(p);
1340       }
1341     }
1342 
1343     uint use_op = use->Opcode();
1344     if(use->is_Cmp()) {       // Enable CMP/BOOL optimization
1345       add_users_to_worklist(use); // Put Bool on worklist
1346       if (use->outcnt() > 0) {
1347         Node* bol = use->raw_out(0);
1348         if (bol->outcnt() > 0) {
1349           Node* iff = bol->raw_out(0);
1350           if (use_op == Op_CmpI &&
1351               iff->is_CountedLoopEnd()) {
1352             CountedLoopEndNode* cle = iff->as_CountedLoopEnd();
1353             if (cle->limit() == n && cle->phi() != NULL) {
1354               // If an opaque node feeds into the limit condition of a
1355               // CountedLoop, we need to process the Phi node for the
1356               // induction variable when the opaque node is removed:
1357               // the range of values taken by the Phi is now known and
1358               // so its type is also known.
1359               _worklist.push(cle->phi());
1360             }
1361           } else if (iff->outcnt() == 2) {
1362             // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the
1363             // phi merging either 0 or 1 onto the worklist
1364             Node* ifproj0 = iff->raw_out(0);
1365             Node* ifproj1 = iff->raw_out(1);
1366             if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) {
1367               Node* region0 = ifproj0->raw_out(0);
1368               Node* region1 = ifproj1->raw_out(0);
1369               if( region0 == region1 )
1370                 add_users_to_worklist0(region0);
1371             }
1372           }
1373         }
1374       }
1375       if (use_op == Op_CmpI) {
1376         Node* in1 = use->in(1);
1377         for (uint i = 0; i < in1->outcnt(); i++) {
1378           if (in1->raw_out(i)->Opcode() == Op_CastII) {
1379             Node* castii = in1->raw_out(i);
1380             if (castii->in(0) != NULL && castii->in(0)->in(0) != NULL && castii->in(0)->in(0)->is_If()) {
1381               Node* ifnode = castii->in(0)->in(0);
1382               if (ifnode->in(1) != NULL && ifnode->in(1)->is_Bool() && ifnode->in(1)->in(1) == use) {
1383                 // Reprocess a CastII node that may depend on an
1384                 // opaque node value when the opaque node is
1385                 // removed. In case it carries a dependency we can do
1386                 // a better job of computing its type.
1387                 _worklist.push(castii);
1388               }
1389             }
1390           }
1391         }
1392       }
1393     }
1394 
1395     // If changed Cast input, check Phi users for simple cycles
1396     if( use->is_ConstraintCast() || use->is_CheckCastPP() ) {
1397       for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1398         Node* u = use->fast_out(i2);
1399         if (u->is_Phi())
1400           _worklist.push(u);
1401       }
1402     }
1403     // If changed LShift inputs, check RShift users for useless sign-ext
1404     if( use_op == Op_LShiftI ) {
1405       for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1406         Node* u = use->fast_out(i2);
1407         if (u->Opcode() == Op_RShiftI)
1408           _worklist.push(u);
1409       }
1410     }
1411     // If changed AddI/SubI inputs, check CmpU for range check optimization.
1412     if (use_op == Op_AddI || use_op == Op_SubI) {
1413       for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1414         Node* u = use->fast_out(i2);
1415         if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) {
1416           _worklist.push(u);
1417         }
1418       }
1419     }
1420     // If changed AddP inputs, check Stores for loop invariant
1421     if( use_op == Op_AddP ) {
1422       for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1423         Node* u = use->fast_out(i2);
1424         if (u->is_Mem())
1425           _worklist.push(u);
1426       }
1427     }
1428     // If changed initialization activity, check dependent Stores
1429     if (use_op == Op_Allocate || use_op == Op_AllocateArray) {
1430       InitializeNode* init = use->as_Allocate()->initialization();
1431       if (init != NULL) {
1432         Node* imem = init->proj_out(TypeFunc::Memory);
1433         if (imem != NULL)  add_users_to_worklist0(imem);
1434       }
1435     }
1436     if (use_op == Op_Initialize) {
1437       Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory);
1438       if (imem != NULL)  add_users_to_worklist0(imem);
1439     }
1440   }
1441 }
1442 
1443 /**
1444  * Remove the speculative part of all types that we know of
1445  */
1446 void PhaseIterGVN::remove_speculative_types()  {
1447   assert(UseTypeSpeculation, "speculation is off");
1448   for (uint i = 0; i < _types.Size(); i++)  {
1449     const Type* t = _types.fast_lookup(i);
1450     if (t != NULL) {
1451       _types.map(i, t->remove_speculative());
1452     }
1453   }
1454   _table.check_no_speculative_types();
1455 }
1456 
1457 //=============================================================================
1458 #ifndef PRODUCT
1459 uint PhaseCCP::_total_invokes   = 0;
1460 uint PhaseCCP::_total_constants = 0;
1461 #endif
1462 //------------------------------PhaseCCP---------------------------------------
1463 // Conditional Constant Propagation, ala Wegman & Zadeck
1464 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) {
1465   NOT_PRODUCT( clear_constants(); )
1466   assert( _worklist.size() == 0, "" );
1467   // Clear out _nodes from IterGVN.  Must be clear to transform call.
1468   _nodes.clear();               // Clear out from IterGVN
1469   analyze();
1470 }
1471 
1472 #ifndef PRODUCT
1473 //------------------------------~PhaseCCP--------------------------------------
1474 PhaseCCP::~PhaseCCP() {
1475   inc_invokes();
1476   _total_constants += count_constants();
1477 }
1478 #endif
1479 
1480 
1481 #ifdef ASSERT
1482 static bool ccp_type_widens(const Type* t, const Type* t0) {
1483   assert(t->meet(t0) == t, "Not monotonic");
1484   switch (t->base() == t0->base() ? t->base() : Type::Top) {
1485   case Type::Int:
1486     assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases");
1487     break;
1488   case Type::Long:
1489     assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases");
1490     break;
1491   }
1492   return true;
1493 }
1494 #endif //ASSERT
1495 
1496 //------------------------------analyze----------------------------------------
1497 void PhaseCCP::analyze() {
1498   // Initialize all types to TOP, optimistic analysis
1499   for (int i = C->unique() - 1; i >= 0; i--)  {
1500     _types.map(i,Type::TOP);
1501   }
1502 
1503   // Push root onto worklist
1504   Unique_Node_List worklist;
1505   worklist.push(C->root());
1506 
1507   // Pull from worklist; compute new value; push changes out.
1508   // This loop is the meat of CCP.
1509   while( worklist.size() ) {
1510     Node *n = worklist.pop();
1511     const Type *t = n->Value(this);
1512     if (t != type(n)) {
1513       assert(ccp_type_widens(t, type(n)), "ccp type must widen");
1514 #ifndef PRODUCT
1515       if( TracePhaseCCP ) {
1516         t->dump();
1517         do { tty->print("\t"); } while (tty->position() < 16);
1518         n->dump();
1519       }
1520 #endif
1521       set_type(n, t);
1522       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1523         Node* m = n->fast_out(i);   // Get user
1524         if (m->is_Region()) {  // New path to Region?  Must recheck Phis too
1525           for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1526             Node* p = m->fast_out(i2); // Propagate changes to uses
1527             if (p->bottom_type() != type(p)) { // If not already bottomed out
1528               worklist.push(p); // Propagate change to user
1529             }
1530           }
1531         }
1532         // If we changed the receiver type to a call, we need to revisit
1533         // the Catch following the call.  It's looking for a non-NULL
1534         // receiver to know when to enable the regular fall-through path
1535         // in addition to the NullPtrException path
1536         if (m->is_Call()) {
1537           for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1538             Node* p = m->fast_out(i2);  // Propagate changes to uses
1539             if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) {
1540               worklist.push(p->unique_out());
1541             }
1542           }
1543         }
1544         if (m->bottom_type() != type(m)) { // If not already bottomed out
1545           worklist.push(m);     // Propagate change to user
1546         }
1547 
1548         // CmpU nodes can get their type information from two nodes up in the
1549         // graph (instead of from the nodes immediately above). Make sure they
1550         // are added to the worklist if nodes they depend on are updated, since
1551         // they could be missed and get wrong types otherwise.
1552         uint m_op = m->Opcode();
1553         if (m_op == Op_AddI || m_op == Op_SubI) {
1554           for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1555             Node* p = m->fast_out(i2); // Propagate changes to uses
1556             if (p->Opcode() == Op_CmpU) {
1557               // Got a CmpU which might need the new type information from node n.
1558               if(p->bottom_type() != type(p)) { // If not already bottomed out
1559                 worklist.push(p); // Propagate change to user
1560               }
1561             }
1562           }
1563         }
1564       }
1565     }
1566   }
1567 }
1568 
1569 //------------------------------do_transform-----------------------------------
1570 // Top level driver for the recursive transformer
1571 void PhaseCCP::do_transform() {
1572   // Correct leaves of new-space Nodes; they point to old-space.
1573   C->set_root( transform(C->root())->as_Root() );
1574   assert( C->top(),  "missing TOP node" );
1575   assert( C->root(), "missing root" );
1576 }
1577 
1578 //------------------------------transform--------------------------------------
1579 // Given a Node in old-space, clone him into new-space.
1580 // Convert any of his old-space children into new-space children.
1581 Node *PhaseCCP::transform( Node *n ) {
1582   Node *new_node = _nodes[n->_idx]; // Check for transformed node
1583   if( new_node != NULL )
1584     return new_node;                // Been there, done that, return old answer
1585   new_node = transform_once(n);     // Check for constant
1586   _nodes.map( n->_idx, new_node );  // Flag as having been cloned
1587 
1588   // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc
1589   GrowableArray <Node *> trstack(C->unique() >> 1);
1590 
1591   trstack.push(new_node);           // Process children of cloned node
1592   while ( trstack.is_nonempty() ) {
1593     Node *clone = trstack.pop();
1594     uint cnt = clone->req();
1595     for( uint i = 0; i < cnt; i++ ) {          // For all inputs do
1596       Node *input = clone->in(i);
1597       if( input != NULL ) {                    // Ignore NULLs
1598         Node *new_input = _nodes[input->_idx]; // Check for cloned input node
1599         if( new_input == NULL ) {
1600           new_input = transform_once(input);   // Check for constant
1601           _nodes.map( input->_idx, new_input );// Flag as having been cloned
1602           trstack.push(new_input);
1603         }
1604         assert( new_input == clone->in(i), "insanity check");
1605       }
1606     }
1607   }
1608   return new_node;
1609 }
1610 
1611 
1612 //------------------------------transform_once---------------------------------
1613 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant.
1614 Node *PhaseCCP::transform_once( Node *n ) {
1615   const Type *t = type(n);
1616   // Constant?  Use constant Node instead
1617   if( t->singleton() ) {
1618     Node *nn = n;               // Default is to return the original constant
1619     if( t == Type::TOP ) {
1620       // cache my top node on the Compile instance
1621       if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) {
1622         C->set_cached_top_node( ConNode::make(C, Type::TOP) );
1623         set_type(C->top(), Type::TOP);
1624       }
1625       nn = C->top();
1626     }
1627     if( !n->is_Con() ) {
1628       if( t != Type::TOP ) {
1629         nn = makecon(t);        // ConNode::make(t);
1630         NOT_PRODUCT( inc_constants(); )
1631       } else if( n->is_Region() ) { // Unreachable region
1632         // Note: nn == C->top()
1633         n->set_req(0, NULL);        // Cut selfreference
1634         // Eagerly remove dead phis to avoid phis copies creation.
1635         for (DUIterator i = n->outs(); n->has_out(i); i++) {
1636           Node* m = n->out(i);
1637           if( m->is_Phi() ) {
1638             assert(type(m) == Type::TOP, "Unreachable region should not have live phis.");
1639             replace_node(m, nn);
1640             --i; // deleted this phi; rescan starting with next position
1641           }
1642         }
1643       }
1644       replace_node(n,nn);       // Update DefUse edges for new constant
1645     }
1646     return nn;
1647   }
1648 
1649   // If x is a TypeNode, capture any more-precise type permanently into Node
1650   if (t != n->bottom_type()) {
1651     hash_delete(n);             // changing bottom type may force a rehash
1652     n->raise_bottom_type(t);
1653     _worklist.push(n);          // n re-enters the hash table via the worklist
1654   }
1655 
1656   // Idealize graph using DU info.  Must clone() into new-space.
1657   // DU info is generally used to show profitability, progress or safety
1658   // (but generally not needed for correctness).
1659   Node *nn = n->Ideal_DU_postCCP(this);
1660 
1661   // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks
1662   switch( n->Opcode() ) {
1663   case Op_FastLock:      // Revisit FastLocks for lock coarsening
1664   case Op_If:
1665   case Op_CountedLoopEnd:
1666   case Op_Region:
1667   case Op_Loop:
1668   case Op_CountedLoop:
1669   case Op_Conv2B:
1670   case Op_Opaque1:
1671   case Op_Opaque2:
1672     _worklist.push(n);
1673     break;
1674   default:
1675     break;
1676   }
1677   if( nn ) {
1678     _worklist.push(n);
1679     // Put users of 'n' onto worklist for second igvn transform
1680     add_users_to_worklist(n);
1681     return nn;
1682   }
1683 
1684   return  n;
1685 }
1686 
1687 //---------------------------------saturate------------------------------------
1688 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type,
1689                                const Type* limit_type) const {
1690   const Type* wide_type = new_type->widen(old_type, limit_type);
1691   if (wide_type != new_type) {          // did we widen?
1692     // If so, we may have widened beyond the limit type.  Clip it back down.
1693     new_type = wide_type->filter(limit_type);
1694   }
1695   return new_type;
1696 }
1697 
1698 //------------------------------print_statistics-------------------------------
1699 #ifndef PRODUCT
1700 void PhaseCCP::print_statistics() {
1701   tty->print_cr("CCP: %d  constants found: %d", _total_invokes, _total_constants);
1702 }
1703 #endif
1704 
1705 
1706 //=============================================================================
1707 #ifndef PRODUCT
1708 uint PhasePeephole::_total_peepholes = 0;
1709 #endif
1710 //------------------------------PhasePeephole----------------------------------
1711 // Conditional Constant Propagation, ala Wegman & Zadeck
1712 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg )
1713   : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) {
1714   NOT_PRODUCT( clear_peepholes(); )
1715 }
1716 
1717 #ifndef PRODUCT
1718 //------------------------------~PhasePeephole---------------------------------
1719 PhasePeephole::~PhasePeephole() {
1720   _total_peepholes += count_peepholes();
1721 }
1722 #endif
1723 
1724 //------------------------------transform--------------------------------------
1725 Node *PhasePeephole::transform( Node *n ) {
1726   ShouldNotCallThis();
1727   return NULL;
1728 }
1729 
1730 //------------------------------do_transform-----------------------------------
1731 void PhasePeephole::do_transform() {
1732   bool method_name_not_printed = true;
1733 
1734   // Examine each basic block
1735   for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) {
1736     Block* block = _cfg.get_block(block_number);
1737     bool block_not_printed = true;
1738 
1739     // and each instruction within a block
1740     uint end_index = block->number_of_nodes();
1741     // block->end_idx() not valid after PhaseRegAlloc
1742     for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) {
1743       Node     *n = block->get_node(instruction_index);
1744       if( n->is_Mach() ) {
1745         MachNode *m = n->as_Mach();
1746         int deleted_count = 0;
1747         // check for peephole opportunities
1748         MachNode *m2 = m->peephole( block, instruction_index, _regalloc, deleted_count, C );
1749         if( m2 != NULL ) {
1750 #ifndef PRODUCT
1751           if( PrintOptoPeephole ) {
1752             // Print method, first time only
1753             if( C->method() && method_name_not_printed ) {
1754               C->method()->print_short_name(); tty->cr();
1755               method_name_not_printed = false;
1756             }
1757             // Print this block
1758             if( Verbose && block_not_printed) {
1759               tty->print_cr("in block");
1760               block->dump();
1761               block_not_printed = false;
1762             }
1763             // Print instructions being deleted
1764             for( int i = (deleted_count - 1); i >= 0; --i ) {
1765               block->get_node(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr();
1766             }
1767             tty->print_cr("replaced with");
1768             // Print new instruction
1769             m2->format(_regalloc);
1770             tty->print("\n\n");
1771           }
1772 #endif
1773           // Remove old nodes from basic block and update instruction_index
1774           // (old nodes still exist and may have edges pointing to them
1775           //  as register allocation info is stored in the allocator using
1776           //  the node index to live range mappings.)
1777           uint safe_instruction_index = (instruction_index - deleted_count);
1778           for( ; (instruction_index > safe_instruction_index); --instruction_index ) {
1779             block->remove_node( instruction_index );
1780           }
1781           // install new node after safe_instruction_index
1782           block->insert_node(m2, safe_instruction_index + 1);
1783           end_index = block->number_of_nodes() - 1; // Recompute new block size
1784           NOT_PRODUCT( inc_peepholes(); )
1785         }
1786       }
1787     }
1788   }
1789 }
1790 
1791 //------------------------------print_statistics-------------------------------
1792 #ifndef PRODUCT
1793 void PhasePeephole::print_statistics() {
1794   tty->print_cr("Peephole: peephole rules applied: %d",  _total_peepholes);
1795 }
1796 #endif
1797 
1798 
1799 //=============================================================================
1800 //------------------------------set_req_X--------------------------------------
1801 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) {
1802   assert( is_not_dead(n), "can not use dead node");
1803   assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" );
1804   Node *old = in(i);
1805   set_req(i, n);
1806 
1807   // old goes dead?
1808   if( old ) {
1809     switch (old->outcnt()) {
1810     case 0:
1811       // Put into the worklist to kill later. We do not kill it now because the
1812       // recursive kill will delete the current node (this) if dead-loop exists
1813       if (!old->is_top())
1814         igvn->_worklist.push( old );
1815       break;
1816     case 1:
1817       if( old->is_Store() || old->has_special_unique_user() )
1818         igvn->add_users_to_worklist( old );
1819       break;
1820     case 2:
1821       if( old->is_Store() )
1822         igvn->add_users_to_worklist( old );
1823       if( old->Opcode() == Op_Region )
1824         igvn->_worklist.push(old);
1825       break;
1826     case 3:
1827       if( old->Opcode() == Op_Region ) {
1828         igvn->_worklist.push(old);
1829         igvn->add_users_to_worklist( old );
1830       }
1831       break;
1832     default:
1833       break;
1834     }
1835   }
1836 
1837 }
1838 
1839 //-------------------------------replace_by-----------------------------------
1840 // Using def-use info, replace one node for another.  Follow the def-use info
1841 // to all users of the OLD node.  Then make all uses point to the NEW node.
1842 void Node::replace_by(Node *new_node) {
1843   assert(!is_top(), "top node has no DU info");
1844   for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) {
1845     Node* use = last_out(i);
1846     uint uses_found = 0;
1847     for (uint j = 0; j < use->len(); j++) {
1848       if (use->in(j) == this) {
1849         if (j < use->req())
1850               use->set_req(j, new_node);
1851         else  use->set_prec(j, new_node);
1852         uses_found++;
1853       }
1854     }
1855     i -= uses_found;    // we deleted 1 or more copies of this edge
1856   }
1857 }
1858 
1859 //=============================================================================
1860 //-----------------------------------------------------------------------------
1861 void Type_Array::grow( uint i ) {
1862   if( !_max ) {
1863     _max = 1;
1864     _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) );
1865     _types[0] = NULL;
1866   }
1867   uint old = _max;
1868   while( i >= _max ) _max <<= 1;        // Double to fit
1869   _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*));
1870   memset( &_types[old], 0, (_max-old)*sizeof(Type*) );
1871 }
1872 
1873 //------------------------------dump-------------------------------------------
1874 #ifndef PRODUCT
1875 void Type_Array::dump() const {
1876   uint max = Size();
1877   for( uint i = 0; i < max; i++ ) {
1878     if( _types[i] != NULL ) {
1879       tty->print("  %d\t== ", i); _types[i]->dump(); tty->cr();
1880     }
1881   }
1882 }
1883 #endif
--- EOF ---