1 /*
   2  * Copyright (c) 2005, 2010, 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 "compiler/compileLog.hpp"
  27 #include "libadt/vectset.hpp"
  28 #include "opto/addnode.hpp"
  29 #include "opto/callnode.hpp"
  30 #include "opto/cfgnode.hpp"
  31 #include "opto/compile.hpp"
  32 #include "opto/connode.hpp"
  33 #include "opto/locknode.hpp"
  34 #include "opto/loopnode.hpp"
  35 #include "opto/macro.hpp"
  36 #include "opto/memnode.hpp"
  37 #include "opto/node.hpp"
  38 #include "opto/phaseX.hpp"
  39 #include "opto/rootnode.hpp"
  40 #include "opto/runtime.hpp"
  41 #include "opto/subnode.hpp"
  42 #include "opto/type.hpp"
  43 #include "runtime/sharedRuntime.hpp"
  44 
  45 
  46 //
  47 // Replace any references to "oldref" in inputs to "use" with "newref".
  48 // Returns the number of replacements made.
  49 //
  50 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
  51   int nreplacements = 0;
  52   uint req = use->req();
  53   for (uint j = 0; j < use->len(); j++) {
  54     Node *uin = use->in(j);
  55     if (uin == oldref) {
  56       if (j < req)
  57         use->set_req(j, newref);
  58       else
  59         use->set_prec(j, newref);
  60       nreplacements++;
  61     } else if (j >= req && uin == NULL) {
  62       break;
  63     }
  64   }
  65   return nreplacements;
  66 }
  67 
  68 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
  69   // Copy debug information and adjust JVMState information
  70   uint old_dbg_start = oldcall->tf()->domain()->cnt();
  71   uint new_dbg_start = newcall->tf()->domain()->cnt();
  72   int jvms_adj  = new_dbg_start - old_dbg_start;
  73   assert (new_dbg_start == newcall->req(), "argument count mismatch");
  74 
  75   Dict* sosn_map = new Dict(cmpkey,hashkey);
  76   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
  77     Node* old_in = oldcall->in(i);
  78     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
  79     if (old_in != NULL && old_in->is_SafePointScalarObject()) {
  80       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
  81       uint old_unique = C->unique();
  82       Node* new_in = old_sosn->clone(jvms_adj, sosn_map);
  83       if (old_unique != C->unique()) {
  84         new_in->set_req(0, newcall->in(0)); // reset control edge
  85         new_in = transform_later(new_in); // Register new node.
  86       }
  87       old_in = new_in;
  88     }
  89     newcall->add_req(old_in);
  90   }
  91 
  92   newcall->set_jvms(oldcall->jvms());
  93   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
  94     jvms->set_map(newcall);
  95     jvms->set_locoff(jvms->locoff()+jvms_adj);
  96     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
  97     jvms->set_monoff(jvms->monoff()+jvms_adj);
  98     jvms->set_scloff(jvms->scloff()+jvms_adj);
  99     jvms->set_endoff(jvms->endoff()+jvms_adj);
 100   }
 101 }
 102 
 103 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
 104   Node* cmp;
 105   if (mask != 0) {
 106     Node* and_node = transform_later(new (C, 3) AndXNode(word, MakeConX(mask)));
 107     cmp = transform_later(new (C, 3) CmpXNode(and_node, MakeConX(bits)));
 108   } else {
 109     cmp = word;
 110   }
 111   Node* bol = transform_later(new (C, 2) BoolNode(cmp, BoolTest::ne));
 112   IfNode* iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
 113   transform_later(iff);
 114 
 115   // Fast path taken.
 116   Node *fast_taken = transform_later( new (C, 1) IfFalseNode(iff) );
 117 
 118   // Fast path not-taken, i.e. slow path
 119   Node *slow_taken = transform_later( new (C, 1) IfTrueNode(iff) );
 120 
 121   if (return_fast_path) {
 122     region->init_req(edge, slow_taken); // Capture slow-control
 123     return fast_taken;
 124   } else {
 125     region->init_req(edge, fast_taken); // Capture fast-control
 126     return slow_taken;
 127   }
 128 }
 129 
 130 //--------------------copy_predefined_input_for_runtime_call--------------------
 131 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
 132   // Set fixed predefined input arguments
 133   call->init_req( TypeFunc::Control, ctrl );
 134   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
 135   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
 136   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
 137   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
 138 }
 139 
 140 //------------------------------make_slow_call---------------------------------
 141 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, address slow_call, const char* leaf_name, Node* slow_path, Node* parm0, Node* parm1) {
 142 
 143   // Slow-path call
 144   int size = slow_call_type->domain()->cnt();
 145  CallNode *call = leaf_name
 146    ? (CallNode*)new (C, size) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
 147    : (CallNode*)new (C, size) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
 148 
 149   // Slow path call has no side-effects, uses few values
 150   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
 151   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
 152   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
 153   copy_call_debug_info(oldcall, call);
 154   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
 155   _igvn.replace_node(oldcall, call);
 156   transform_later(call);
 157 
 158   return call;
 159 }
 160 
 161 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
 162   _fallthroughproj = NULL;
 163   _fallthroughcatchproj = NULL;
 164   _ioproj_fallthrough = NULL;
 165   _ioproj_catchall = NULL;
 166   _catchallcatchproj = NULL;
 167   _memproj_fallthrough = NULL;
 168   _memproj_catchall = NULL;
 169   _resproj = NULL;
 170   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
 171     ProjNode *pn = call->fast_out(i)->as_Proj();
 172     switch (pn->_con) {
 173       case TypeFunc::Control:
 174       {
 175         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 176         _fallthroughproj = pn;
 177         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 178         const Node *cn = pn->fast_out(j);
 179         if (cn->is_Catch()) {
 180           ProjNode *cpn = NULL;
 181           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 182             cpn = cn->fast_out(k)->as_Proj();
 183             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 184             if (cpn->_con == CatchProjNode::fall_through_index)
 185               _fallthroughcatchproj = cpn;
 186             else {
 187               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 188               _catchallcatchproj = cpn;
 189             }
 190           }
 191         }
 192         break;
 193       }
 194       case TypeFunc::I_O:
 195         if (pn->_is_io_use)
 196           _ioproj_catchall = pn;
 197         else
 198           _ioproj_fallthrough = pn;
 199         break;
 200       case TypeFunc::Memory:
 201         if (pn->_is_io_use)
 202           _memproj_catchall = pn;
 203         else
 204           _memproj_fallthrough = pn;
 205         break;
 206       case TypeFunc::Parms:
 207         _resproj = pn;
 208         break;
 209       default:
 210         assert(false, "unexpected projection from allocation node.");
 211     }
 212   }
 213 
 214 }
 215 
 216 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
 217 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
 218   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
 219   if (!UseG1GC) {
 220     // vanilla/CMS post barrier
 221     Node *shift = p2x->unique_out();
 222     Node *addp = shift->unique_out();
 223     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 224       Node *st = addp->last_out(j);
 225       assert(st->is_Store(), "store required");
 226       _igvn.replace_node(st, st->in(MemNode::Memory));
 227     }
 228   } else {
 229     // G1 pre/post barriers
 230     assert(p2x->outcnt() == 2, "expects 2 users: Xor and URShift nodes");
 231     // It could be only one user, URShift node, in Object.clone() instrinsic
 232     // but the new allocation is passed to arraycopy stub and it could not
 233     // be scalar replaced. So we don't check the case.
 234 
 235     // Remove G1 post barrier.
 236 
 237     // Search for CastP2X->Xor->URShift->Cmp path which
 238     // checks if the store done to a different from the value's region.
 239     // And replace Cmp with #0 (false) to collapse G1 post barrier.
 240     Node* xorx = NULL;
 241     for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
 242       Node* u = p2x->fast_out(i);
 243       if (u->Opcode() == Op_XorX) {
 244         xorx = u;
 245         break;
 246       }
 247     }
 248     assert(xorx != NULL, "missing G1 post barrier");
 249     Node* shift = xorx->unique_out();
 250     Node* cmpx = shift->unique_out();
 251     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
 252     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
 253     "missing region check in G1 post barrier");
 254     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 255 
 256     // Remove G1 pre barrier.
 257 
 258     // Search "if (marking != 0)" check and set it to "false".
 259     Node* this_region = p2x->in(0);
 260     assert(this_region != NULL, "");
 261     // There is no G1 pre barrier if previous stored value is NULL
 262     // (for example, after initialization).
 263     if (this_region->is_Region() && this_region->req() == 3) {
 264       int ind = 1;
 265       if (!this_region->in(ind)->is_IfFalse()) {
 266         ind = 2;
 267       }
 268       if (this_region->in(ind)->is_IfFalse()) {
 269         Node* bol = this_region->in(ind)->in(0)->in(1);
 270         assert(bol->is_Bool(), "");
 271         cmpx = bol->in(1);
 272         if (bol->as_Bool()->_test._test == BoolTest::ne &&
 273             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
 274             cmpx->in(1)->is_Load()) {
 275           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
 276           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
 277                                               PtrQueue::byte_offset_of_active());
 278           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
 279               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
 280               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
 281             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 282           }
 283         }
 284       }
 285     }
 286     // Now CastP2X can be removed since it is used only on dead path
 287     // which currently still alive until igvn optimize it.
 288     assert(p2x->unique_out()->Opcode() == Op_URShiftX, "");
 289     _igvn.replace_node(p2x, top());
 290   }
 291 }
 292 
 293 // Search for a memory operation for the specified memory slice.
 294 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
 295   Node *orig_mem = mem;
 296   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 297   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
 298   while (true) {
 299     if (mem == alloc_mem || mem == start_mem ) {
 300       return mem;  // hit one of our sentinels
 301     } else if (mem->is_MergeMem()) {
 302       mem = mem->as_MergeMem()->memory_at(alias_idx);
 303     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 304       Node *in = mem->in(0);
 305       // we can safely skip over safepoints, calls, locks and membars because we
 306       // already know that the object is safe to eliminate.
 307       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 308         return in;
 309       } else if (in->is_Call()) {
 310         CallNode *call = in->as_Call();
 311         if (!call->may_modify(tinst, phase)) {
 312           mem = call->in(TypeFunc::Memory);
 313         }
 314         mem = in->in(TypeFunc::Memory);
 315       } else if (in->is_MemBar()) {
 316         mem = in->in(TypeFunc::Memory);
 317       } else {
 318         assert(false, "unexpected projection");
 319       }
 320     } else if (mem->is_Store()) {
 321       const TypePtr* atype = mem->as_Store()->adr_type();
 322       int adr_idx = Compile::current()->get_alias_index(atype);
 323       if (adr_idx == alias_idx) {
 324         assert(atype->isa_oopptr(), "address type must be oopptr");
 325         int adr_offset = atype->offset();
 326         uint adr_iid = atype->is_oopptr()->instance_id();
 327         // Array elements references have the same alias_idx
 328         // but different offset and different instance_id.
 329         if (adr_offset == offset && adr_iid == alloc->_idx)
 330           return mem;
 331       } else {
 332         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 333       }
 334       mem = mem->in(MemNode::Memory);
 335     } else if (mem->is_ClearArray()) {
 336       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
 337         // Can not bypass initialization of the instance
 338         // we are looking.
 339         debug_only(intptr_t offset;)
 340         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
 341         InitializeNode* init = alloc->as_Allocate()->initialization();
 342         // We are looking for stored value, return Initialize node
 343         // or memory edge from Allocate node.
 344         if (init != NULL)
 345           return init;
 346         else
 347           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
 348       }
 349       // Otherwise skip it (the call updated 'mem' value).
 350     } else if (mem->Opcode() == Op_SCMemProj) {
 351       assert(mem->in(0)->is_LoadStore(), "sanity");
 352       const TypePtr* atype = mem->in(0)->in(MemNode::Address)->bottom_type()->is_ptr();
 353       int adr_idx = Compile::current()->get_alias_index(atype);
 354       if (adr_idx == alias_idx) {
 355         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 356         return NULL;
 357       }
 358       mem = mem->in(0)->in(MemNode::Memory);
 359     } else {
 360       return mem;
 361     }
 362     assert(mem != orig_mem, "dead memory loop");
 363   }
 364 }
 365 
 366 //
 367 // Given a Memory Phi, compute a value Phi containing the values from stores
 368 // on the input paths.
 369 // Note: this function is recursive, its depth is limied by the "level" argument
 370 // Returns the computed Phi, or NULL if it cannot compute it.
 371 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, Node *alloc, Node_Stack *value_phis, int level) {
 372   assert(mem->is_Phi(), "sanity");
 373   int alias_idx = C->get_alias_index(adr_t);
 374   int offset = adr_t->offset();
 375   int instance_id = adr_t->instance_id();
 376 
 377   // Check if an appropriate value phi already exists.
 378   Node* region = mem->in(0);
 379   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 380     Node* phi = region->fast_out(k);
 381     if (phi->is_Phi() && phi != mem &&
 382         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
 383       return phi;
 384     }
 385   }
 386   // Check if an appropriate new value phi already exists.
 387   Node* new_phi = NULL;
 388   uint size = value_phis->size();
 389   for (uint i=0; i < size; i++) {
 390     if ( mem->_idx == value_phis->index_at(i) ) {
 391       return value_phis->node_at(i);
 392     }
 393   }
 394 
 395   if (level <= 0) {
 396     return NULL; // Give up: phi tree too deep
 397   }
 398   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 399   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 400 
 401   uint length = mem->req();
 402   GrowableArray <Node *> values(length, length, NULL);
 403 
 404   // create a new Phi for the value
 405   PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
 406   transform_later(phi);
 407   value_phis->push(phi, mem->_idx);
 408 
 409   for (uint j = 1; j < length; j++) {
 410     Node *in = mem->in(j);
 411     if (in == NULL || in->is_top()) {
 412       values.at_put(j, in);
 413     } else  {
 414       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
 415       if (val == start_mem || val == alloc_mem) {
 416         // hit a sentinel, return appropriate 0 value
 417         values.at_put(j, _igvn.zerocon(ft));
 418         continue;
 419       }
 420       if (val->is_Initialize()) {
 421         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 422       }
 423       if (val == NULL) {
 424         return NULL;  // can't find a value on this path
 425       }
 426       if (val == mem) {
 427         values.at_put(j, mem);
 428       } else if (val->is_Store()) {
 429         values.at_put(j, val->in(MemNode::ValueIn));
 430       } else if(val->is_Proj() && val->in(0) == alloc) {
 431         values.at_put(j, _igvn.zerocon(ft));
 432       } else if (val->is_Phi()) {
 433         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
 434         if (val == NULL) {
 435           return NULL;
 436         }
 437         values.at_put(j, val);
 438       } else if (val->Opcode() == Op_SCMemProj) {
 439         assert(val->in(0)->is_LoadStore(), "sanity");
 440         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 441         return NULL;
 442       } else {
 443 #ifdef ASSERT
 444         val->dump();
 445         assert(false, "unknown node on this path");
 446 #endif
 447         return NULL;  // unknown node on this path
 448       }
 449     }
 450   }
 451   // Set Phi's inputs
 452   for (uint j = 1; j < length; j++) {
 453     if (values.at(j) == mem) {
 454       phi->init_req(j, phi);
 455     } else {
 456       phi->init_req(j, values.at(j));
 457     }
 458   }
 459   return phi;
 460 }
 461 
 462 // Search the last value stored into the object's field.
 463 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
 464   assert(adr_t->is_known_instance_field(), "instance required");
 465   int instance_id = adr_t->instance_id();
 466   assert((uint)instance_id == alloc->_idx, "wrong allocation");
 467 
 468   int alias_idx = C->get_alias_index(adr_t);
 469   int offset = adr_t->offset();
 470   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 471   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
 472   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 473   Arena *a = Thread::current()->resource_area();
 474   VectorSet visited(a);
 475 
 476 
 477   bool done = sfpt_mem == alloc_mem;
 478   Node *mem = sfpt_mem;
 479   while (!done) {
 480     if (visited.test_set(mem->_idx)) {
 481       return NULL;  // found a loop, give up
 482     }
 483     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
 484     if (mem == start_mem || mem == alloc_mem) {
 485       done = true;  // hit a sentinel, return appropriate 0 value
 486     } else if (mem->is_Initialize()) {
 487       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 488       if (mem == NULL) {
 489         done = true; // Something go wrong.
 490       } else if (mem->is_Store()) {
 491         const TypePtr* atype = mem->as_Store()->adr_type();
 492         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 493         done = true;
 494       }
 495     } else if (mem->is_Store()) {
 496       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 497       assert(atype != NULL, "address type must be oopptr");
 498       assert(C->get_alias_index(atype) == alias_idx &&
 499              atype->is_known_instance_field() && atype->offset() == offset &&
 500              atype->instance_id() == instance_id, "store is correct memory slice");
 501       done = true;
 502     } else if (mem->is_Phi()) {
 503       // try to find a phi's unique input
 504       Node *unique_input = NULL;
 505       Node *top = C->top();
 506       for (uint i = 1; i < mem->req(); i++) {
 507         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
 508         if (n == NULL || n == top || n == mem) {
 509           continue;
 510         } else if (unique_input == NULL) {
 511           unique_input = n;
 512         } else if (unique_input != n) {
 513           unique_input = top;
 514           break;
 515         }
 516       }
 517       if (unique_input != NULL && unique_input != top) {
 518         mem = unique_input;
 519       } else {
 520         done = true;
 521       }
 522     } else {
 523       assert(false, "unexpected node");
 524     }
 525   }
 526   if (mem != NULL) {
 527     if (mem == start_mem || mem == alloc_mem) {
 528       // hit a sentinel, return appropriate 0 value
 529       return _igvn.zerocon(ft);
 530     } else if (mem->is_Store()) {
 531       return mem->in(MemNode::ValueIn);
 532     } else if (mem->is_Phi()) {
 533       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 534       Node_Stack value_phis(a, 8);
 535       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
 536       if (phi != NULL) {
 537         return phi;
 538       } else {
 539         // Kill all new Phis
 540         while(value_phis.is_nonempty()) {
 541           Node* n = value_phis.node();
 542           _igvn.replace_node(n, C->top());
 543           value_phis.pop();
 544         }
 545       }
 546     }
 547   }
 548   // Something go wrong.
 549   return NULL;
 550 }
 551 
 552 // Check the possibility of scalar replacement.
 553 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 554   //  Scan the uses of the allocation to check for anything that would
 555   //  prevent us from eliminating it.
 556   NOT_PRODUCT( const char* fail_eliminate = NULL; )
 557   DEBUG_ONLY( Node* disq_node = NULL; )
 558   bool  can_eliminate = true;
 559 
 560   Node* res = alloc->result_cast();
 561   const TypeOopPtr* res_type = NULL;
 562   if (res == NULL) {
 563     // All users were eliminated.
 564   } else if (!res->is_CheckCastPP()) {
 565     alloc->_is_scalar_replaceable = false;  // don't try again
 566     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 567     can_eliminate = false;
 568   } else {
 569     res_type = _igvn.type(res)->isa_oopptr();
 570     if (res_type == NULL) {
 571       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 572       can_eliminate = false;
 573     } else if (res_type->isa_aryptr()) {
 574       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 575       if (length < 0) {
 576         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 577         can_eliminate = false;
 578       }
 579     }
 580   }
 581 
 582   if (can_eliminate && res != NULL) {
 583     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
 584                                j < jmax && can_eliminate; j++) {
 585       Node* use = res->fast_out(j);
 586 
 587       if (use->is_AddP()) {
 588         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
 589         int offset = addp_type->offset();
 590 
 591         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 592           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
 593           can_eliminate = false;
 594           break;
 595         }
 596         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 597                                    k < kmax && can_eliminate; k++) {
 598           Node* n = use->fast_out(k);
 599           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
 600             DEBUG_ONLY(disq_node = n;)
 601             if (n->is_Load() || n->is_LoadStore()) {
 602               NOT_PRODUCT(fail_eliminate = "Field load";)
 603             } else {
 604               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
 605             }
 606             can_eliminate = false;
 607           }
 608         }
 609       } else if (use->is_SafePoint()) {
 610         SafePointNode* sfpt = use->as_SafePoint();
 611         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 612           // Object is passed as argument.
 613           DEBUG_ONLY(disq_node = use;)
 614           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 615           can_eliminate = false;
 616         }
 617         Node* sfptMem = sfpt->memory();
 618         if (sfptMem == NULL || sfptMem->is_top()) {
 619           DEBUG_ONLY(disq_node = use;)
 620           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
 621           can_eliminate = false;
 622         } else {
 623           safepoints.append_if_missing(sfpt);
 624         }
 625       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 626         if (use->is_Phi()) {
 627           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 628             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 629           } else {
 630             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 631           }
 632           DEBUG_ONLY(disq_node = use;)
 633         } else {
 634           if (use->Opcode() == Op_Return) {
 635             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 636           }else {
 637             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 638           }
 639           DEBUG_ONLY(disq_node = use;)
 640         }
 641         can_eliminate = false;
 642       }
 643     }
 644   }
 645 
 646 #ifndef PRODUCT
 647   if (PrintEliminateAllocations) {
 648     if (can_eliminate) {
 649       tty->print("Scalar ");
 650       if (res == NULL)
 651         alloc->dump();
 652       else
 653         res->dump();
 654     } else {
 655       tty->print("NotScalar (%s)", fail_eliminate);
 656       if (res == NULL)
 657         alloc->dump();
 658       else
 659         res->dump();
 660 #ifdef ASSERT
 661       if (disq_node != NULL) {
 662           tty->print("  >>>> ");
 663           disq_node->dump();
 664       }
 665 #endif /*ASSERT*/
 666     }
 667   }
 668 #endif
 669   return can_eliminate;
 670 }
 671 
 672 // Do scalar replacement.
 673 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 674   GrowableArray <SafePointNode *> safepoints_done;
 675 
 676   ciKlass* klass = NULL;
 677   ciInstanceKlass* iklass = NULL;
 678   int nfields = 0;
 679   int array_base;
 680   int element_size;
 681   BasicType basic_elem_type;
 682   ciType* elem_type;
 683 
 684   Node* res = alloc->result_cast();
 685   const TypeOopPtr* res_type = NULL;
 686   if (res != NULL) { // Could be NULL when there are no users
 687     res_type = _igvn.type(res)->isa_oopptr();
 688   }
 689 
 690   if (res != NULL) {
 691     klass = res_type->klass();
 692     if (res_type->isa_instptr()) {
 693       // find the fields of the class which will be needed for safepoint debug information
 694       assert(klass->is_instance_klass(), "must be an instance klass.");
 695       iklass = klass->as_instance_klass();
 696       nfields = iklass->nof_nonstatic_fields();
 697     } else {
 698       // find the array's elements which will be needed for safepoint debug information
 699       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 700       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
 701       elem_type = klass->as_array_klass()->element_type();
 702       basic_elem_type = elem_type->basic_type();
 703       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 704       element_size = type2aelembytes(basic_elem_type);
 705     }
 706   }
 707   //
 708   // Process the safepoint uses
 709   //
 710   while (safepoints.length() > 0) {
 711     SafePointNode* sfpt = safepoints.pop();
 712     Node* mem = sfpt->memory();
 713     uint first_ind = sfpt->req();
 714     SafePointScalarObjectNode* sobj = new (C, 1) SafePointScalarObjectNode(res_type,
 715 #ifdef ASSERT
 716                                                  alloc,
 717 #endif
 718                                                  first_ind, nfields);
 719     sobj->init_req(0, sfpt->in(TypeFunc::Control));
 720     transform_later(sobj);
 721 
 722     // Scan object's fields adding an input to the safepoint for each field.
 723     for (int j = 0; j < nfields; j++) {
 724       intptr_t offset;
 725       ciField* field = NULL;
 726       if (iklass != NULL) {
 727         field = iklass->nonstatic_field_at(j);
 728         offset = field->offset();
 729         elem_type = field->type();
 730         basic_elem_type = field->layout_type();
 731       } else {
 732         offset = array_base + j * (intptr_t)element_size;
 733       }
 734 
 735       const Type *field_type;
 736       // The next code is taken from Parse::do_get_xxx().
 737       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
 738         if (!elem_type->is_loaded()) {
 739           field_type = TypeInstPtr::BOTTOM;
 740         } else if (field != NULL && field->is_constant() && field->is_static()) {
 741           // This can happen if the constant oop is non-perm.
 742           ciObject* con = field->constant_value().as_object();
 743           // Do not "join" in the previous type; it doesn't add value,
 744           // and may yield a vacuous result if the field is of interface type.
 745           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 746           assert(field_type != NULL, "field singleton type must be consistent");
 747         } else {
 748           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 749         }
 750         if (UseCompressedOops) {
 751           field_type = field_type->make_narrowoop();
 752           basic_elem_type = T_NARROWOOP;
 753         }
 754       } else {
 755         field_type = Type::get_const_basic_type(basic_elem_type);
 756       }
 757 
 758       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
 759 
 760       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
 761       if (field_val == NULL) {
 762         // we weren't able to find a value for this field,
 763         // give up on eliminating this allocation
 764         alloc->_is_scalar_replaceable = false;  // don't try again
 765         // remove any extra entries we added to the safepoint
 766         uint last = sfpt->req() - 1;
 767         for (int k = 0;  k < j; k++) {
 768           sfpt->del_req(last--);
 769         }
 770         // rollback processed safepoints
 771         while (safepoints_done.length() > 0) {
 772           SafePointNode* sfpt_done = safepoints_done.pop();
 773           // remove any extra entries we added to the safepoint
 774           last = sfpt_done->req() - 1;
 775           for (int k = 0;  k < nfields; k++) {
 776             sfpt_done->del_req(last--);
 777           }
 778           JVMState *jvms = sfpt_done->jvms();
 779           jvms->set_endoff(sfpt_done->req());
 780           // Now make a pass over the debug information replacing any references
 781           // to SafePointScalarObjectNode with the allocated object.
 782           int start = jvms->debug_start();
 783           int end   = jvms->debug_end();
 784           for (int i = start; i < end; i++) {
 785             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 786               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 787               if (scobj->first_index() == sfpt_done->req() &&
 788                   scobj->n_fields() == (uint)nfields) {
 789                 assert(scobj->alloc() == alloc, "sanity");
 790                 sfpt_done->set_req(i, res);
 791               }
 792             }
 793           }
 794         }
 795 #ifndef PRODUCT
 796         if (PrintEliminateAllocations) {
 797           if (field != NULL) {
 798             tty->print("=== At SafePoint node %d can't find value of Field: ",
 799                        sfpt->_idx);
 800             field->print();
 801             int field_idx = C->get_alias_index(field_addr_type);
 802             tty->print(" (alias_idx=%d)", field_idx);
 803           } else { // Array's element
 804             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
 805                        sfpt->_idx, j);
 806           }
 807           tty->print(", which prevents elimination of: ");
 808           if (res == NULL)
 809             alloc->dump();
 810           else
 811             res->dump();
 812         }
 813 #endif
 814         return false;
 815       }
 816       if (UseCompressedOops && field_type->isa_narrowoop()) {
 817         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
 818         // to be able scalar replace the allocation.
 819         if (field_val->is_EncodeP()) {
 820           field_val = field_val->in(1);
 821         } else {
 822           field_val = transform_later(new (C, 2) DecodeNNode(field_val, field_val->bottom_type()->make_ptr()));
 823         }
 824       }
 825       sfpt->add_req(field_val);
 826     }
 827     JVMState *jvms = sfpt->jvms();
 828     jvms->set_endoff(sfpt->req());
 829     // Now make a pass over the debug information replacing any references
 830     // to the allocated object with "sobj"
 831     int start = jvms->debug_start();
 832     int end   = jvms->debug_end();
 833     for (int i = start; i < end; i++) {
 834       if (sfpt->in(i) == res) {
 835         sfpt->set_req(i, sobj);
 836       }
 837     }
 838     safepoints_done.append_if_missing(sfpt); // keep it for rollback
 839   }
 840   return true;
 841 }
 842 
 843 // Process users of eliminated allocation.
 844 void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
 845   Node* res = alloc->result_cast();
 846   if (res != NULL) {
 847     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
 848       Node *use = res->last_out(j);
 849       uint oc1 = res->outcnt();
 850 
 851       if (use->is_AddP()) {
 852         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
 853           Node *n = use->last_out(k);
 854           uint oc2 = use->outcnt();
 855           if (n->is_Store()) {
 856 #ifdef ASSERT
 857             // Verify that there is no dependent MemBarVolatile nodes,
 858             // they should be removed during IGVN, see MemBarNode::Ideal().
 859             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
 860                                        p < pmax; p++) {
 861               Node* mb = n->fast_out(p);
 862               assert(mb->is_Initialize() || !mb->is_MemBar() ||
 863                      mb->req() <= MemBarNode::Precedent ||
 864                      mb->in(MemBarNode::Precedent) != n,
 865                      "MemBarVolatile should be eliminated for non-escaping object");
 866             }
 867 #endif
 868             _igvn.replace_node(n, n->in(MemNode::Memory));
 869           } else {
 870             eliminate_card_mark(n);
 871           }
 872           k -= (oc2 - use->outcnt());
 873         }
 874       } else {
 875         eliminate_card_mark(use);
 876       }
 877       j -= (oc1 - res->outcnt());
 878     }
 879     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
 880     _igvn.remove_dead_node(res);
 881   }
 882 
 883   //
 884   // Process other users of allocation's projections
 885   //
 886   if (_resproj != NULL && _resproj->outcnt() != 0) {
 887     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
 888       Node *use = _resproj->last_out(j);
 889       uint oc1 = _resproj->outcnt();
 890       if (use->is_Initialize()) {
 891         // Eliminate Initialize node.
 892         InitializeNode *init = use->as_Initialize();
 893         assert(init->outcnt() <= 2, "only a control and memory projection expected");
 894         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
 895         if (ctrl_proj != NULL) {
 896            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
 897           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
 898         }
 899         Node *mem_proj = init->proj_out(TypeFunc::Memory);
 900         if (mem_proj != NULL) {
 901           Node *mem = init->in(TypeFunc::Memory);
 902 #ifdef ASSERT
 903           if (mem->is_MergeMem()) {
 904             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
 905           } else {
 906             assert(mem == _memproj_fallthrough, "allocation memory projection");
 907           }
 908 #endif
 909           _igvn.replace_node(mem_proj, mem);
 910         }
 911       } else if (use->is_AddP()) {
 912         // raw memory addresses used only by the initialization
 913         _igvn.replace_node(use, C->top());
 914       } else  {
 915         assert(false, "only Initialize or AddP expected");
 916       }
 917       j -= (oc1 - _resproj->outcnt());
 918     }
 919   }
 920   if (_fallthroughcatchproj != NULL) {
 921     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
 922   }
 923   if (_memproj_fallthrough != NULL) {
 924     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
 925   }
 926   if (_memproj_catchall != NULL) {
 927     _igvn.replace_node(_memproj_catchall, C->top());
 928   }
 929   if (_ioproj_fallthrough != NULL) {
 930     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
 931   }
 932   if (_ioproj_catchall != NULL) {
 933     _igvn.replace_node(_ioproj_catchall, C->top());
 934   }
 935   if (_catchallcatchproj != NULL) {
 936     _igvn.replace_node(_catchallcatchproj, C->top());
 937   }
 938 }
 939 
 940 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
 941 
 942   if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {
 943     return false;
 944   }
 945 
 946   extract_call_projections(alloc);
 947 
 948   GrowableArray <SafePointNode *> safepoints;
 949   if (!can_eliminate_allocation(alloc, safepoints)) {
 950     return false;
 951   }
 952 
 953   if (!scalar_replacement(alloc, safepoints)) {
 954     return false;
 955   }
 956 
 957   CompileLog* log = C->log();
 958   if (log != NULL) {
 959     Node* klass = alloc->in(AllocateNode::KlassNode);
 960     const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
 961     log->head("eliminate_allocation type='%d'",
 962               log->identify(tklass->klass()));
 963     JVMState* p = alloc->jvms();
 964     while (p != NULL) {
 965       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
 966       p = p->caller();
 967     }
 968     log->tail("eliminate_allocation");
 969   }
 970 
 971   process_users_of_allocation(alloc);
 972 
 973 #ifndef PRODUCT
 974   if (PrintEliminateAllocations) {
 975     if (alloc->is_AllocateArray())
 976       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
 977     else
 978       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
 979   }
 980 #endif
 981 
 982   return true;
 983 }
 984 
 985 
 986 //---------------------------set_eden_pointers-------------------------
 987 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
 988   if (UseTLAB) {                // Private allocation: load from TLS
 989     Node* thread = transform_later(new (C, 1) ThreadLocalNode());
 990     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
 991     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
 992     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
 993     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
 994   } else {                      // Shared allocation: load from globals
 995     CollectedHeap* ch = Universe::heap();
 996     address top_adr = (address)ch->top_addr();
 997     address end_adr = (address)ch->end_addr();
 998     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
 999     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1000   }
1001 }
1002 
1003 
1004 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1005   Node* adr = basic_plus_adr(base, offset);
1006   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1007   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
1008   transform_later(value);
1009   return value;
1010 }
1011 
1012 
1013 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1014   Node* adr = basic_plus_adr(base, offset);
1015   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
1016   transform_later(mem);
1017   return mem;
1018 }
1019 
1020 //=============================================================================
1021 //
1022 //                              A L L O C A T I O N
1023 //
1024 // Allocation attempts to be fast in the case of frequent small objects.
1025 // It breaks down like this:
1026 //
1027 // 1) Size in doublewords is computed.  This is a constant for objects and
1028 // variable for most arrays.  Doubleword units are used to avoid size
1029 // overflow of huge doubleword arrays.  We need doublewords in the end for
1030 // rounding.
1031 //
1032 // 2) Size is checked for being 'too large'.  Too-large allocations will go
1033 // the slow path into the VM.  The slow path can throw any required
1034 // exceptions, and does all the special checks for very large arrays.  The
1035 // size test can constant-fold away for objects.  For objects with
1036 // finalizers it constant-folds the otherway: you always go slow with
1037 // finalizers.
1038 //
1039 // 3) If NOT using TLABs, this is the contended loop-back point.
1040 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
1041 //
1042 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
1043 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
1044 // "size*8" we always enter the VM, where "largish" is a constant picked small
1045 // enough that there's always space between the eden max and 4Gig (old space is
1046 // there so it's quite large) and large enough that the cost of entering the VM
1047 // is dwarfed by the cost to initialize the space.
1048 //
1049 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1050 // down.  If contended, repeat at step 3.  If using TLABs normal-store
1051 // adjusted heap top back down; there is no contention.
1052 //
1053 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
1054 // fields.
1055 //
1056 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1057 // oop flavor.
1058 //
1059 //=============================================================================
1060 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1061 // Allocations bigger than this always go the slow route.
1062 // This value must be small enough that allocation attempts that need to
1063 // trigger exceptions go the slow route.  Also, it must be small enough so
1064 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1065 //=============================================================================j//
1066 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1067 // The allocator will coalesce int->oop copies away.  See comment in
1068 // coalesce.cpp about how this works.  It depends critically on the exact
1069 // code shape produced here, so if you are changing this code shape
1070 // make sure the GC info for the heap-top is correct in and around the
1071 // slow-path call.
1072 //
1073 
1074 void PhaseMacroExpand::expand_allocate_common(
1075             AllocateNode* alloc, // allocation node to be expanded
1076             Node* length,  // array length for an array allocation
1077             const TypeFunc* slow_call_type, // Type of slow call
1078             address slow_call_address  // Address of slow call
1079     )
1080 {
1081 
1082   Node* ctrl = alloc->in(TypeFunc::Control);
1083   Node* mem  = alloc->in(TypeFunc::Memory);
1084   Node* i_o  = alloc->in(TypeFunc::I_O);
1085   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
1086   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
1087   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1088 
1089   assert(ctrl != NULL, "must have control");
1090   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1091   // they will not be used if "always_slow" is set
1092   enum { slow_result_path = 1, fast_result_path = 2 };
1093   Node *result_region;
1094   Node *result_phi_rawmem;
1095   Node *result_phi_rawoop;
1096   Node *result_phi_i_o;
1097 
1098   // The initial slow comparison is a size check, the comparison
1099   // we want to do is a BoolTest::gt
1100   bool always_slow = false;
1101   int tv = _igvn.find_int_con(initial_slow_test, -1);
1102   if (tv >= 0) {
1103     always_slow = (tv == 1);
1104     initial_slow_test = NULL;
1105   } else {
1106     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1107   }
1108 
1109   if (C->env()->dtrace_alloc_probes() ||
1110       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
1111                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
1112     // Force slow-path allocation
1113     always_slow = true;
1114     initial_slow_test = NULL;
1115   }
1116 
1117 
1118   enum { too_big_or_final_path = 1, need_gc_path = 2 };
1119   Node *slow_region = NULL;
1120   Node *toobig_false = ctrl;
1121 
1122   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1123   // generate the initial test if necessary
1124   if (initial_slow_test != NULL ) {
1125     slow_region = new (C, 3) RegionNode(3);
1126 
1127     // Now make the initial failure test.  Usually a too-big test but
1128     // might be a TRUE for finalizers or a fancy class check for
1129     // newInstance0.
1130     IfNode *toobig_iff = new (C, 2) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1131     transform_later(toobig_iff);
1132     // Plug the failing-too-big test into the slow-path region
1133     Node *toobig_true = new (C, 1) IfTrueNode( toobig_iff );
1134     transform_later(toobig_true);
1135     slow_region    ->init_req( too_big_or_final_path, toobig_true );
1136     toobig_false = new (C, 1) IfFalseNode( toobig_iff );
1137     transform_later(toobig_false);
1138   } else {         // No initial test, just fall into next case
1139     toobig_false = ctrl;
1140     debug_only(slow_region = NodeSentinel);
1141   }
1142 
1143   Node *slow_mem = mem;  // save the current memory state for slow path
1144   // generate the fast allocation code unless we know that the initial test will always go slow
1145   if (!always_slow) {
1146     // Fast path modifies only raw memory.
1147     if (mem->is_MergeMem()) {
1148       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1149     }
1150 
1151     Node* eden_top_adr;
1152     Node* eden_end_adr;
1153 
1154     set_eden_pointers(eden_top_adr, eden_end_adr);
1155 
1156     // Load Eden::end.  Loop invariant and hoisted.
1157     //
1158     // Note: We set the control input on "eden_end" and "old_eden_top" when using
1159     //       a TLAB to work around a bug where these values were being moved across
1160     //       a safepoint.  These are not oops, so they cannot be include in the oop
1161     //       map, but the can be changed by a GC.   The proper way to fix this would
1162     //       be to set the raw memory state when generating a  SafepointNode.  However
1163     //       this will require extensive changes to the loop optimization in order to
1164     //       prevent a degradation of the optimization.
1165     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
1166     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1167 
1168     // allocate the Region and Phi nodes for the result
1169     result_region = new (C, 3) RegionNode(3);
1170     result_phi_rawmem = new (C, 3) PhiNode( result_region, Type::MEMORY, TypeRawPtr::BOTTOM );
1171     result_phi_rawoop = new (C, 3) PhiNode( result_region, TypeRawPtr::BOTTOM );
1172     result_phi_i_o    = new (C, 3) PhiNode( result_region, Type::ABIO ); // I/O is used for Prefetch
1173 
1174     // We need a Region for the loop-back contended case.
1175     enum { fall_in_path = 1, contended_loopback_path = 2 };
1176     Node *contended_region;
1177     Node *contended_phi_rawmem;
1178     if( UseTLAB ) {
1179       contended_region = toobig_false;
1180       contended_phi_rawmem = mem;
1181     } else {
1182       contended_region = new (C, 3) RegionNode(3);
1183       contended_phi_rawmem = new (C, 3) PhiNode( contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1184       // Now handle the passing-too-big test.  We fall into the contended
1185       // loop-back merge point.
1186       contended_region    ->init_req( fall_in_path, toobig_false );
1187       contended_phi_rawmem->init_req( fall_in_path, mem );
1188       transform_later(contended_region);
1189       transform_later(contended_phi_rawmem);
1190     }
1191 
1192     // Load(-locked) the heap top.
1193     // See note above concerning the control input when using a TLAB
1194     Node *old_eden_top = UseTLAB
1195       ? new (C, 3) LoadPNode     ( ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM )
1196       : new (C, 3) LoadPLockedNode( contended_region, contended_phi_rawmem, eden_top_adr );
1197 
1198     transform_later(old_eden_top);
1199     // Add to heap top to get a new heap top
1200     Node *new_eden_top = new (C, 4) AddPNode( top(), old_eden_top, size_in_bytes );
1201     transform_later(new_eden_top);
1202     // Check for needing a GC; compare against heap end
1203     Node *needgc_cmp = new (C, 3) CmpPNode( new_eden_top, eden_end );
1204     transform_later(needgc_cmp);
1205     Node *needgc_bol = new (C, 2) BoolNode( needgc_cmp, BoolTest::ge );
1206     transform_later(needgc_bol);
1207     IfNode *needgc_iff = new (C, 2) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1208     transform_later(needgc_iff);
1209 
1210     // Plug the failing-heap-space-need-gc test into the slow-path region
1211     Node *needgc_true = new (C, 1) IfTrueNode( needgc_iff );
1212     transform_later(needgc_true);
1213     if( initial_slow_test ) {
1214       slow_region    ->init_req( need_gc_path, needgc_true );
1215       // This completes all paths into the slow merge point
1216       transform_later(slow_region);
1217     } else {                      // No initial slow path needed!
1218       // Just fall from the need-GC path straight into the VM call.
1219       slow_region    = needgc_true;
1220     }
1221     // No need for a GC.  Setup for the Store-Conditional
1222     Node *needgc_false = new (C, 1) IfFalseNode( needgc_iff );
1223     transform_later(needgc_false);
1224 
1225     // Grab regular I/O before optional prefetch may change it.
1226     // Slow-path does no I/O so just set it to the original I/O.
1227     result_phi_i_o->init_req( slow_result_path, i_o );
1228 
1229     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1230                               old_eden_top, new_eden_top, length);
1231 
1232     // Store (-conditional) the modified eden top back down.
1233     // StorePConditional produces flags for a test PLUS a modified raw
1234     // memory state.
1235     Node *store_eden_top;
1236     Node *fast_oop_ctrl;
1237     if( UseTLAB ) {
1238       store_eden_top = new (C, 4) StorePNode( needgc_false, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, new_eden_top );
1239       transform_later(store_eden_top);
1240       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1241     } else {
1242       store_eden_top = new (C, 5) StorePConditionalNode( needgc_false, contended_phi_rawmem, eden_top_adr, new_eden_top, old_eden_top );
1243       transform_later(store_eden_top);
1244       Node *contention_check = new (C, 2) BoolNode( store_eden_top, BoolTest::ne );
1245       transform_later(contention_check);
1246       store_eden_top = new (C, 1) SCMemProjNode(store_eden_top);
1247       transform_later(store_eden_top);
1248 
1249       // If not using TLABs, check to see if there was contention.
1250       IfNode *contention_iff = new (C, 2) IfNode ( needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN );
1251       transform_later(contention_iff);
1252       Node *contention_true = new (C, 1) IfTrueNode( contention_iff );
1253       transform_later(contention_true);
1254       // If contention, loopback and try again.
1255       contended_region->init_req( contended_loopback_path, contention_true );
1256       contended_phi_rawmem->init_req( contended_loopback_path, store_eden_top );
1257 
1258       // Fast-path succeeded with no contention!
1259       Node *contention_false = new (C, 1) IfFalseNode( contention_iff );
1260       transform_later(contention_false);
1261       fast_oop_ctrl = contention_false;
1262     }
1263 
1264     // Rename successful fast-path variables to make meaning more obvious
1265     Node* fast_oop        = old_eden_top;
1266     Node* fast_oop_rawmem = store_eden_top;
1267     fast_oop_rawmem = initialize_object(alloc,
1268                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1269                                         klass_node, length, size_in_bytes);
1270 
1271     if (C->env()->dtrace_extended_probes()) {
1272       // Slow-path call
1273       int size = TypeFunc::Parms + 2;
1274       CallLeafNode *call = new (C, size) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1275                                                       CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1276                                                       "dtrace_object_alloc",
1277                                                       TypeRawPtr::BOTTOM);
1278 
1279       // Get base of thread-local storage area
1280       Node* thread = new (C, 1) ThreadLocalNode();
1281       transform_later(thread);
1282 
1283       call->init_req(TypeFunc::Parms+0, thread);
1284       call->init_req(TypeFunc::Parms+1, fast_oop);
1285       call->init_req( TypeFunc::Control, fast_oop_ctrl );
1286       call->init_req( TypeFunc::I_O    , top() )        ;   // does no i/o
1287       call->init_req( TypeFunc::Memory , fast_oop_rawmem );
1288       call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1289       call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1290       transform_later(call);
1291       fast_oop_ctrl = new (C, 1) ProjNode(call,TypeFunc::Control);
1292       transform_later(fast_oop_ctrl);
1293       fast_oop_rawmem = new (C, 1) ProjNode(call,TypeFunc::Memory);
1294       transform_later(fast_oop_rawmem);
1295     }
1296 
1297     // Plug in the successful fast-path into the result merge point
1298     result_region    ->init_req( fast_result_path, fast_oop_ctrl );
1299     result_phi_rawoop->init_req( fast_result_path, fast_oop );
1300     result_phi_i_o   ->init_req( fast_result_path, i_o );
1301     result_phi_rawmem->init_req( fast_result_path, fast_oop_rawmem );
1302   } else {
1303     slow_region = ctrl;
1304   }
1305 
1306   // Generate slow-path call
1307   CallNode *call = new (C, slow_call_type->domain()->cnt())
1308     CallStaticJavaNode(slow_call_type, slow_call_address,
1309                        OptoRuntime::stub_name(slow_call_address),
1310                        alloc->jvms()->bci(),
1311                        TypePtr::BOTTOM);
1312   call->init_req( TypeFunc::Control, slow_region );
1313   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
1314   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1315   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1316   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1317 
1318   call->init_req(TypeFunc::Parms+0, klass_node);
1319   if (length != NULL) {
1320     call->init_req(TypeFunc::Parms+1, length);
1321   }
1322 
1323   // Copy debug information and adjust JVMState information, then replace
1324   // allocate node with the call
1325   copy_call_debug_info((CallNode *) alloc,  call);
1326   if (!always_slow) {
1327     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1328   }
1329   _igvn.replace_node(alloc, call);
1330   transform_later(call);
1331 
1332   // Identify the output projections from the allocate node and
1333   // adjust any references to them.
1334   // The control and io projections look like:
1335   //
1336   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1337   //  Allocate                   Catch
1338   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1339   //
1340   //  We are interested in the CatchProj nodes.
1341   //
1342   extract_call_projections(call);
1343 
1344   // An allocate node has separate memory projections for the uses on the control and i_o paths
1345   // Replace uses of the control memory projection with result_phi_rawmem (unless we are only generating a slow call)
1346   if (!always_slow && _memproj_fallthrough != NULL) {
1347     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1348       Node *use = _memproj_fallthrough->fast_out(i);
1349       _igvn.hash_delete(use);
1350       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1351       _igvn._worklist.push(use);
1352       // back up iterator
1353       --i;
1354     }
1355   }
1356   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete _memproj_catchall so
1357   // we end up with a call that has only 1 memory projection
1358   if (_memproj_catchall != NULL ) {
1359     if (_memproj_fallthrough == NULL) {
1360       _memproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::Memory);
1361       transform_later(_memproj_fallthrough);
1362     }
1363     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1364       Node *use = _memproj_catchall->fast_out(i);
1365       _igvn.hash_delete(use);
1366       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1367       _igvn._worklist.push(use);
1368       // back up iterator
1369       --i;
1370     }
1371   }
1372 
1373   // An allocate node has separate i_o projections for the uses on the control and i_o paths
1374   // Replace uses of the control i_o projection with result_phi_i_o (unless we are only generating a slow call)
1375   if (_ioproj_fallthrough == NULL) {
1376     _ioproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::I_O);
1377     transform_later(_ioproj_fallthrough);
1378   } else if (!always_slow) {
1379     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1380       Node *use = _ioproj_fallthrough->fast_out(i);
1381 
1382       _igvn.hash_delete(use);
1383       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1384       _igvn._worklist.push(use);
1385       // back up iterator
1386       --i;
1387     }
1388   }
1389   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete _ioproj_catchall so
1390   // we end up with a call that has only 1 control projection
1391   if (_ioproj_catchall != NULL ) {
1392     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1393       Node *use = _ioproj_catchall->fast_out(i);
1394       _igvn.hash_delete(use);
1395       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1396       _igvn._worklist.push(use);
1397       // back up iterator
1398       --i;
1399     }
1400   }
1401 
1402   // if we generated only a slow call, we are done
1403   if (always_slow)
1404     return;
1405 
1406 
1407   if (_fallthroughcatchproj != NULL) {
1408     ctrl = _fallthroughcatchproj->clone();
1409     transform_later(ctrl);
1410     _igvn.replace_node(_fallthroughcatchproj, result_region);
1411   } else {
1412     ctrl = top();
1413   }
1414   Node *slow_result;
1415   if (_resproj == NULL) {
1416     // no uses of the allocation result
1417     slow_result = top();
1418   } else {
1419     slow_result = _resproj->clone();
1420     transform_later(slow_result);
1421     _igvn.replace_node(_resproj, result_phi_rawoop);
1422   }
1423 
1424   // Plug slow-path into result merge point
1425   result_region    ->init_req( slow_result_path, ctrl );
1426   result_phi_rawoop->init_req( slow_result_path, slow_result);
1427   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1428   transform_later(result_region);
1429   transform_later(result_phi_rawoop);
1430   transform_later(result_phi_rawmem);
1431   transform_later(result_phi_i_o);
1432   // This completes all paths into the result merge point
1433 }
1434 
1435 
1436 // Helper for PhaseMacroExpand::expand_allocate_common.
1437 // Initializes the newly-allocated storage.
1438 Node*
1439 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1440                                     Node* control, Node* rawmem, Node* object,
1441                                     Node* klass_node, Node* length,
1442                                     Node* size_in_bytes) {
1443   InitializeNode* init = alloc->initialization();
1444   // Store the klass & mark bits
1445   Node* mark_node = NULL;
1446   // For now only enable fast locking for non-array types
1447   if (UseBiasedLocking && (length == NULL)) {
1448     mark_node = make_load(control, rawmem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeRawPtr::BOTTOM, T_ADDRESS);
1449   } else {
1450     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1451   }
1452   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1453 
1454   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_OBJECT);
1455   int header_size = alloc->minimum_header_size();  // conservatively small
1456 
1457   // Array length
1458   if (length != NULL) {         // Arrays need length field
1459     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1460     // conservatively small header size:
1461     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1462     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1463     if (k->is_array_klass())    // we know the exact header size in most cases:
1464       header_size = Klass::layout_helper_header_size(k->layout_helper());
1465   }
1466 
1467   // Clear the object body, if necessary.
1468   if (init == NULL) {
1469     // The init has somehow disappeared; be cautious and clear everything.
1470     //
1471     // This can happen if a node is allocated but an uncommon trap occurs
1472     // immediately.  In this case, the Initialize gets associated with the
1473     // trap, and may be placed in a different (outer) loop, if the Allocate
1474     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
1475     // there can be two Allocates to one Initialize.  The answer in all these
1476     // edge cases is safety first.  It is always safe to clear immediately
1477     // within an Allocate, and then (maybe or maybe not) clear some more later.
1478     if (!ZeroTLAB)
1479       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1480                                             header_size, size_in_bytes,
1481                                             &_igvn);
1482   } else {
1483     if (!init->is_complete()) {
1484       // Try to win by zeroing only what the init does not store.
1485       // We can also try to do some peephole optimizations,
1486       // such as combining some adjacent subword stores.
1487       rawmem = init->complete_stores(control, rawmem, object,
1488                                      header_size, size_in_bytes, &_igvn);
1489     }
1490     // We have no more use for this link, since the AllocateNode goes away:
1491     init->set_req(InitializeNode::RawAddress, top());
1492     // (If we keep the link, it just confuses the register allocator,
1493     // who thinks he sees a real use of the address by the membar.)
1494   }
1495 
1496   return rawmem;
1497 }
1498 
1499 // Generate prefetch instructions for next allocations.
1500 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1501                                         Node*& contended_phi_rawmem,
1502                                         Node* old_eden_top, Node* new_eden_top,
1503                                         Node* length) {
1504    enum { fall_in_path = 1, pf_path = 2 };
1505    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1506       // Generate prefetch allocation with watermark check.
1507       // As an allocation hits the watermark, we will prefetch starting
1508       // at a "distance" away from watermark.
1509 
1510       Node *pf_region = new (C, 3) RegionNode(3);
1511       Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
1512                                                 TypeRawPtr::BOTTOM );
1513       // I/O is used for Prefetch
1514       Node *pf_phi_abio = new (C, 3) PhiNode( pf_region, Type::ABIO );
1515 
1516       Node *thread = new (C, 1) ThreadLocalNode();
1517       transform_later(thread);
1518 
1519       Node *eden_pf_adr = new (C, 4) AddPNode( top()/*not oop*/, thread,
1520                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1521       transform_later(eden_pf_adr);
1522 
1523       Node *old_pf_wm = new (C, 3) LoadPNode( needgc_false,
1524                                    contended_phi_rawmem, eden_pf_adr,
1525                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
1526       transform_later(old_pf_wm);
1527 
1528       // check against new_eden_top
1529       Node *need_pf_cmp = new (C, 3) CmpPNode( new_eden_top, old_pf_wm );
1530       transform_later(need_pf_cmp);
1531       Node *need_pf_bol = new (C, 2) BoolNode( need_pf_cmp, BoolTest::ge );
1532       transform_later(need_pf_bol);
1533       IfNode *need_pf_iff = new (C, 2) IfNode( needgc_false, need_pf_bol,
1534                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1535       transform_later(need_pf_iff);
1536 
1537       // true node, add prefetchdistance
1538       Node *need_pf_true = new (C, 1) IfTrueNode( need_pf_iff );
1539       transform_later(need_pf_true);
1540 
1541       Node *need_pf_false = new (C, 1) IfFalseNode( need_pf_iff );
1542       transform_later(need_pf_false);
1543 
1544       Node *new_pf_wmt = new (C, 4) AddPNode( top(), old_pf_wm,
1545                                     _igvn.MakeConX(AllocatePrefetchDistance) );
1546       transform_later(new_pf_wmt );
1547       new_pf_wmt->set_req(0, need_pf_true);
1548 
1549       Node *store_new_wmt = new (C, 4) StorePNode( need_pf_true,
1550                                        contended_phi_rawmem, eden_pf_adr,
1551                                        TypeRawPtr::BOTTOM, new_pf_wmt );
1552       transform_later(store_new_wmt);
1553 
1554       // adding prefetches
1555       pf_phi_abio->init_req( fall_in_path, i_o );
1556 
1557       Node *prefetch_adr;
1558       Node *prefetch;
1559       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1560       uint step_size = AllocatePrefetchStepSize;
1561       uint distance = 0;
1562 
1563       for ( uint i = 0; i < lines; i++ ) {
1564         prefetch_adr = new (C, 4) AddPNode( old_pf_wm, new_pf_wmt,
1565                                             _igvn.MakeConX(distance) );
1566         transform_later(prefetch_adr);
1567         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
1568         transform_later(prefetch);
1569         distance += step_size;
1570         i_o = prefetch;
1571       }
1572       pf_phi_abio->set_req( pf_path, i_o );
1573 
1574       pf_region->init_req( fall_in_path, need_pf_false );
1575       pf_region->init_req( pf_path, need_pf_true );
1576 
1577       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1578       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1579 
1580       transform_later(pf_region);
1581       transform_later(pf_phi_rawmem);
1582       transform_later(pf_phi_abio);
1583 
1584       needgc_false = pf_region;
1585       contended_phi_rawmem = pf_phi_rawmem;
1586       i_o = pf_phi_abio;
1587    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1588       // Insert a prefetch for each allocation only on the fast-path
1589       Node *pf_region = new (C, 3) RegionNode(3);
1590       Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
1591                                                 TypeRawPtr::BOTTOM );
1592 
1593       // Generate several prefetch instructions only for arrays.
1594       uint lines = (length != NULL) ? AllocatePrefetchLines : 1;
1595       uint step_size = AllocatePrefetchStepSize;
1596       uint distance = AllocatePrefetchDistance;
1597 
1598       // Next cache address.
1599       Node *cache_adr = new (C, 4) AddPNode(old_eden_top, old_eden_top,
1600                                             _igvn.MakeConX(distance));
1601       transform_later(cache_adr);
1602       cache_adr = new (C, 2) CastP2XNode(needgc_false, cache_adr);
1603       transform_later(cache_adr);
1604       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1605       cache_adr = new (C, 3) AndXNode(cache_adr, mask);
1606       transform_later(cache_adr);
1607       cache_adr = new (C, 2) CastX2PNode(cache_adr);
1608       transform_later(cache_adr);
1609 
1610       // Prefetch
1611       Node *prefetch = new (C, 3) PrefetchWriteNode( contended_phi_rawmem, cache_adr );
1612       prefetch->set_req(0, needgc_false);
1613       transform_later(prefetch);
1614       contended_phi_rawmem = prefetch;
1615       Node *prefetch_adr;
1616       distance = step_size;
1617       for ( uint i = 1; i < lines; i++ ) {
1618         prefetch_adr = new (C, 4) AddPNode( cache_adr, cache_adr,
1619                                             _igvn.MakeConX(distance) );
1620         transform_later(prefetch_adr);
1621         prefetch = new (C, 3) PrefetchWriteNode( contended_phi_rawmem, prefetch_adr );
1622         transform_later(prefetch);
1623         distance += step_size;
1624         contended_phi_rawmem = prefetch;
1625       }
1626    } else if( AllocatePrefetchStyle > 0 ) {
1627       // Insert a prefetch for each allocation only on the fast-path
1628       Node *prefetch_adr;
1629       Node *prefetch;
1630       // Generate several prefetch instructions only for arrays.
1631       uint lines = (length != NULL) ? AllocatePrefetchLines : 1;
1632       uint step_size = AllocatePrefetchStepSize;
1633       uint distance = AllocatePrefetchDistance;
1634       for ( uint i = 0; i < lines; i++ ) {
1635         prefetch_adr = new (C, 4) AddPNode( old_eden_top, new_eden_top,
1636                                             _igvn.MakeConX(distance) );
1637         transform_later(prefetch_adr);
1638         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
1639         // Do not let it float too high, since if eden_top == eden_end,
1640         // both might be null.
1641         if( i == 0 ) { // Set control for first prefetch, next follows it
1642           prefetch->init_req(0, needgc_false);
1643         }
1644         transform_later(prefetch);
1645         distance += step_size;
1646         i_o = prefetch;
1647       }
1648    }
1649    return i_o;
1650 }
1651 
1652 
1653 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1654   expand_allocate_common(alloc, NULL,
1655                          OptoRuntime::new_instance_Type(),
1656                          OptoRuntime::new_instance_Java());
1657 }
1658 
1659 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1660   Node* length = alloc->in(AllocateNode::ALength);
1661   expand_allocate_common(alloc, length,
1662                          OptoRuntime::new_array_Type(),
1663                          OptoRuntime::new_array_Java());
1664 }
1665 
1666 
1667 // we have determined that this lock/unlock can be eliminated, we simply
1668 // eliminate the node without expanding it.
1669 //
1670 // Note:  The membar's associated with the lock/unlock are currently not
1671 //        eliminated.  This should be investigated as a future enhancement.
1672 //
1673 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
1674 
1675   if (!alock->is_eliminated()) {
1676     return false;
1677   }
1678   if (alock->is_Lock() && !alock->is_coarsened()) {
1679       // Create new "eliminated" BoxLock node and use it
1680       // in monitor debug info for the same object.
1681       BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
1682       Node* obj = alock->obj_node();
1683       if (!oldbox->is_eliminated()) {
1684         BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1685         newbox->set_eliminated();
1686         transform_later(newbox);
1687         // Replace old box node with new box for all users
1688         // of the same object.
1689         for (uint i = 0; i < oldbox->outcnt();) {
1690 
1691           bool next_edge = true;
1692           Node* u = oldbox->raw_out(i);
1693           if (u == alock) {
1694             i++;
1695             continue; // It will be removed below
1696           }
1697           if (u->is_Lock() &&
1698               u->as_Lock()->obj_node() == obj &&
1699               // oldbox could be referenced in debug info also
1700               u->as_Lock()->box_node() == oldbox) {
1701             assert(u->as_Lock()->is_eliminated(), "sanity");
1702             _igvn.hash_delete(u);
1703             u->set_req(TypeFunc::Parms + 1, newbox);
1704             next_edge = false;
1705 #ifdef ASSERT
1706           } else if (u->is_Unlock() && u->as_Unlock()->obj_node() == obj) {
1707             assert(u->as_Unlock()->is_eliminated(), "sanity");
1708 #endif
1709           }
1710           // Replace old box in monitor debug info.
1711           if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1712             SafePointNode* sfn = u->as_SafePoint();
1713             JVMState* youngest_jvms = sfn->jvms();
1714             int max_depth = youngest_jvms->depth();
1715             for (int depth = 1; depth <= max_depth; depth++) {
1716               JVMState* jvms = youngest_jvms->of_depth(depth);
1717               int num_mon  = jvms->nof_monitors();
1718               // Loop over monitors
1719               for (int idx = 0; idx < num_mon; idx++) {
1720                 Node* obj_node = sfn->monitor_obj(jvms, idx);
1721                 Node* box_node = sfn->monitor_box(jvms, idx);
1722                 if (box_node == oldbox && obj_node == obj) {
1723                   int j = jvms->monitor_box_offset(idx);
1724                   _igvn.hash_delete(u);
1725                   u->set_req(j, newbox);
1726                   next_edge = false;
1727                 }
1728               } // for (int idx = 0;
1729             } // for (int depth = 1;
1730           } // if (u->is_SafePoint()
1731           if (next_edge) i++;
1732         } // for (uint i = 0; i < oldbox->outcnt();)
1733       } // if (!oldbox->is_eliminated())
1734   } // if (alock->is_Lock() && !lock->is_coarsened())
1735 
1736   CompileLog* log = C->log();
1737   if (log != NULL) {
1738     log->head("eliminate_lock lock='%d'",
1739               alock->is_Lock());
1740     JVMState* p = alock->jvms();
1741     while (p != NULL) {
1742       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1743       p = p->caller();
1744     }
1745     log->tail("eliminate_lock");
1746   }
1747 
1748   #ifndef PRODUCT
1749   if (PrintEliminateLocks) {
1750     if (alock->is_Lock()) {
1751       tty->print_cr("++++ Eliminating: %d Lock", alock->_idx);
1752     } else {
1753       tty->print_cr("++++ Eliminating: %d Unlock", alock->_idx);
1754     }
1755   }
1756   #endif
1757 
1758   Node* mem  = alock->in(TypeFunc::Memory);
1759   Node* ctrl = alock->in(TypeFunc::Control);
1760 
1761   extract_call_projections(alock);
1762   // There are 2 projections from the lock.  The lock node will
1763   // be deleted when its last use is subsumed below.
1764   assert(alock->outcnt() == 2 &&
1765          _fallthroughproj != NULL &&
1766          _memproj_fallthrough != NULL,
1767          "Unexpected projections from Lock/Unlock");
1768 
1769   Node* fallthroughproj = _fallthroughproj;
1770   Node* memproj_fallthrough = _memproj_fallthrough;
1771 
1772   // The memory projection from a lock/unlock is RawMem
1773   // The input to a Lock is merged memory, so extract its RawMem input
1774   // (unless the MergeMem has been optimized away.)
1775   if (alock->is_Lock()) {
1776     // Seach for MemBarAcquire node and delete it also.
1777     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
1778     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquire, "");
1779     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
1780     Node* memproj = membar->proj_out(TypeFunc::Memory);
1781     _igvn.replace_node(ctrlproj, fallthroughproj);
1782     _igvn.replace_node(memproj, memproj_fallthrough);
1783 
1784     // Delete FastLock node also if this Lock node is unique user
1785     // (a loop peeling may clone a Lock node).
1786     Node* flock = alock->as_Lock()->fastlock_node();
1787     if (flock->outcnt() == 1) {
1788       assert(flock->unique_out() == alock, "sanity");
1789       _igvn.replace_node(flock, top());
1790     }
1791   }
1792 
1793   // Seach for MemBarRelease node and delete it also.
1794   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
1795       ctrl->in(0)->is_MemBar()) {
1796     MemBarNode* membar = ctrl->in(0)->as_MemBar();
1797     assert(membar->Opcode() == Op_MemBarRelease &&
1798            mem->is_Proj() && membar == mem->in(0), "");
1799     _igvn.replace_node(fallthroughproj, ctrl);
1800     _igvn.replace_node(memproj_fallthrough, mem);
1801     fallthroughproj = ctrl;
1802     memproj_fallthrough = mem;
1803     ctrl = membar->in(TypeFunc::Control);
1804     mem  = membar->in(TypeFunc::Memory);
1805   }
1806 
1807   _igvn.replace_node(fallthroughproj, ctrl);
1808   _igvn.replace_node(memproj_fallthrough, mem);
1809   return true;
1810 }
1811 
1812 
1813 //------------------------------expand_lock_node----------------------
1814 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
1815 
1816   Node* ctrl = lock->in(TypeFunc::Control);
1817   Node* mem = lock->in(TypeFunc::Memory);
1818   Node* obj = lock->obj_node();
1819   Node* box = lock->box_node();
1820   Node* flock = lock->fastlock_node();
1821 
1822   // Make the merge point
1823   Node *region;
1824   Node *mem_phi;
1825   Node *slow_path;
1826 
1827   if (UseOptoBiasInlining) {
1828     /*
1829      *  See the full description in MacroAssembler::biased_locking_enter().
1830      *
1831      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
1832      *    // The object is biased.
1833      *    proto_node = klass->prototype_header;
1834      *    o_node = thread | proto_node;
1835      *    x_node = o_node ^ mark_word;
1836      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
1837      *      // Done.
1838      *    } else {
1839      *      if( (x_node & biased_lock_mask) != 0 ) {
1840      *        // The klass's prototype header is no longer biased.
1841      *        cas(&mark_word, mark_word, proto_node)
1842      *        goto cas_lock;
1843      *      } else {
1844      *        // The klass's prototype header is still biased.
1845      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
1846      *          old = mark_word;
1847      *          new = o_node;
1848      *        } else {
1849      *          // Different thread or anonymous biased.
1850      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
1851      *          new = thread | old;
1852      *        }
1853      *        // Try to rebias.
1854      *        if( cas(&mark_word, old, new) == 0 ) {
1855      *          // Done.
1856      *        } else {
1857      *          goto slow_path; // Failed.
1858      *        }
1859      *      }
1860      *    }
1861      *  } else {
1862      *    // The object is not biased.
1863      *    cas_lock:
1864      *    if( FastLock(obj) == 0 ) {
1865      *      // Done.
1866      *    } else {
1867      *      slow_path:
1868      *      OptoRuntime::complete_monitor_locking_Java(obj);
1869      *    }
1870      *  }
1871      */
1872 
1873     region  = new (C, 5) RegionNode(5);
1874     // create a Phi for the memory state
1875     mem_phi = new (C, 5) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
1876 
1877     Node* fast_lock_region  = new (C, 3) RegionNode(3);
1878     Node* fast_lock_mem_phi = new (C, 3) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1879 
1880     // First, check mark word for the biased lock pattern.
1881     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
1882 
1883     // Get fast path - mark word has the biased lock pattern.
1884     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
1885                          markOopDesc::biased_lock_mask_in_place,
1886                          markOopDesc::biased_lock_pattern, true);
1887     // fast_lock_region->in(1) is set to slow path.
1888     fast_lock_mem_phi->init_req(1, mem);
1889 
1890     // Now check that the lock is biased to the current thread and has
1891     // the same epoch and bias as Klass::_prototype_header.
1892 
1893     // Special-case a fresh allocation to avoid building nodes:
1894     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
1895     if (klass_node == NULL) {
1896       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1897       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
1898 #ifdef _LP64
1899       if (UseCompressedOops && klass_node->is_DecodeN()) {
1900         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
1901         klass_node->in(1)->init_req(0, ctrl);
1902       } else
1903 #endif
1904       klass_node->init_req(0, ctrl);
1905     }
1906     Node *proto_node = make_load(ctrl, mem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeX_X, TypeX_X->basic_type());
1907 
1908     Node* thread = transform_later(new (C, 1) ThreadLocalNode());
1909     Node* cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
1910     Node* o_node = transform_later(new (C, 3) OrXNode(cast_thread, proto_node));
1911     Node* x_node = transform_later(new (C, 3) XorXNode(o_node, mark_node));
1912 
1913     // Get slow path - mark word does NOT match the value.
1914     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
1915                                       (~markOopDesc::age_mask_in_place), 0);
1916     // region->in(3) is set to fast path - the object is biased to the current thread.
1917     mem_phi->init_req(3, mem);
1918 
1919 
1920     // Mark word does NOT match the value (thread | Klass::_prototype_header).
1921 
1922 
1923     // First, check biased pattern.
1924     // Get fast path - _prototype_header has the same biased lock pattern.
1925     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
1926                           markOopDesc::biased_lock_mask_in_place, 0, true);
1927 
1928     not_biased_ctrl = fast_lock_region->in(2); // Slow path
1929     // fast_lock_region->in(2) - the prototype header is no longer biased
1930     // and we have to revoke the bias on this object.
1931     // We are going to try to reset the mark of this object to the prototype
1932     // value and fall through to the CAS-based locking scheme.
1933     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
1934     Node* cas = new (C, 5) StoreXConditionalNode(not_biased_ctrl, mem, adr,
1935                                                  proto_node, mark_node);
1936     transform_later(cas);
1937     Node* proj = transform_later( new (C, 1) SCMemProjNode(cas));
1938     fast_lock_mem_phi->init_req(2, proj);
1939 
1940 
1941     // Second, check epoch bits.
1942     Node* rebiased_region  = new (C, 3) RegionNode(3);
1943     Node* old_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
1944     Node* new_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
1945 
1946     // Get slow path - mark word does NOT match epoch bits.
1947     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
1948                                       markOopDesc::epoch_mask_in_place, 0);
1949     // The epoch of the current bias is not valid, attempt to rebias the object
1950     // toward the current thread.
1951     rebiased_region->init_req(2, epoch_ctrl);
1952     old_phi->init_req(2, mark_node);
1953     new_phi->init_req(2, o_node);
1954 
1955     // rebiased_region->in(1) is set to fast path.
1956     // The epoch of the current bias is still valid but we know
1957     // nothing about the owner; it might be set or it might be clear.
1958     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
1959                              markOopDesc::age_mask_in_place |
1960                              markOopDesc::epoch_mask_in_place);
1961     Node* old = transform_later(new (C, 3) AndXNode(mark_node, cmask));
1962     cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
1963     Node* new_mark = transform_later(new (C, 3) OrXNode(cast_thread, old));
1964     old_phi->init_req(1, old);
1965     new_phi->init_req(1, new_mark);
1966 
1967     transform_later(rebiased_region);
1968     transform_later(old_phi);
1969     transform_later(new_phi);
1970 
1971     // Try to acquire the bias of the object using an atomic operation.
1972     // If this fails we will go in to the runtime to revoke the object's bias.
1973     cas = new (C, 5) StoreXConditionalNode(rebiased_region, mem, adr,
1974                                            new_phi, old_phi);
1975     transform_later(cas);
1976     proj = transform_later( new (C, 1) SCMemProjNode(cas));
1977 
1978     // Get slow path - Failed to CAS.
1979     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
1980     mem_phi->init_req(4, proj);
1981     // region->in(4) is set to fast path - the object is rebiased to the current thread.
1982 
1983     // Failed to CAS.
1984     slow_path  = new (C, 3) RegionNode(3);
1985     Node *slow_mem = new (C, 3) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
1986 
1987     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
1988     slow_mem->init_req(1, proj);
1989 
1990     // Call CAS-based locking scheme (FastLock node).
1991 
1992     transform_later(fast_lock_region);
1993     transform_later(fast_lock_mem_phi);
1994 
1995     // Get slow path - FastLock failed to lock the object.
1996     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
1997     mem_phi->init_req(2, fast_lock_mem_phi);
1998     // region->in(2) is set to fast path - the object is locked to the current thread.
1999 
2000     slow_path->init_req(2, ctrl); // Capture slow-control
2001     slow_mem->init_req(2, fast_lock_mem_phi);
2002 
2003     transform_later(slow_path);
2004     transform_later(slow_mem);
2005     // Reset lock's memory edge.
2006     lock->set_req(TypeFunc::Memory, slow_mem);
2007 
2008   } else {
2009     region  = new (C, 3) RegionNode(3);
2010     // create a Phi for the memory state
2011     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2012 
2013     // Optimize test; set region slot 2
2014     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2015     mem_phi->init_req(2, mem);
2016   }
2017 
2018   // Make slow path call
2019   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2020 
2021   extract_call_projections(call);
2022 
2023   // Slow path can only throw asynchronous exceptions, which are always
2024   // de-opted.  So the compiler thinks the slow-call can never throw an
2025   // exception.  If it DOES throw an exception we would need the debug
2026   // info removed first (since if it throws there is no monitor).
2027   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2028            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2029 
2030   // Capture slow path
2031   // disconnect fall-through projection from call and create a new one
2032   // hook up users of fall-through projection to region
2033   Node *slow_ctrl = _fallthroughproj->clone();
2034   transform_later(slow_ctrl);
2035   _igvn.hash_delete(_fallthroughproj);
2036   _fallthroughproj->disconnect_inputs(NULL);
2037   region->init_req(1, slow_ctrl);
2038   // region inputs are now complete
2039   transform_later(region);
2040   _igvn.replace_node(_fallthroughproj, region);
2041 
2042   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
2043   mem_phi->init_req(1, memproj );
2044   transform_later(mem_phi);
2045   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2046 }
2047 
2048 //------------------------------expand_unlock_node----------------------
2049 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2050 
2051   Node* ctrl = unlock->in(TypeFunc::Control);
2052   Node* mem = unlock->in(TypeFunc::Memory);
2053   Node* obj = unlock->obj_node();
2054   Node* box = unlock->box_node();
2055 
2056   // No need for a null check on unlock
2057 
2058   // Make the merge point
2059   Node *region;
2060   Node *mem_phi;
2061 
2062   if (UseOptoBiasInlining) {
2063     // Check for biased locking unlock case, which is a no-op.
2064     // See the full description in MacroAssembler::biased_locking_exit().
2065     region  = new (C, 4) RegionNode(4);
2066     // create a Phi for the memory state
2067     mem_phi = new (C, 4) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2068     mem_phi->init_req(3, mem);
2069 
2070     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2071     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2072                          markOopDesc::biased_lock_mask_in_place,
2073                          markOopDesc::biased_lock_pattern);
2074   } else {
2075     region  = new (C, 3) RegionNode(3);
2076     // create a Phi for the memory state
2077     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2078   }
2079 
2080   FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box );
2081   funlock = transform_later( funlock )->as_FastUnlock();
2082   // Optimize test; set region slot 2
2083   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2084 
2085   CallNode *call = make_slow_call( (CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), "complete_monitor_unlocking_C", slow_path, obj, box );
2086 
2087   extract_call_projections(call);
2088 
2089   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2090            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2091 
2092   // No exceptions for unlocking
2093   // Capture slow path
2094   // disconnect fall-through projection from call and create a new one
2095   // hook up users of fall-through projection to region
2096   Node *slow_ctrl = _fallthroughproj->clone();
2097   transform_later(slow_ctrl);
2098   _igvn.hash_delete(_fallthroughproj);
2099   _fallthroughproj->disconnect_inputs(NULL);
2100   region->init_req(1, slow_ctrl);
2101   // region inputs are now complete
2102   transform_later(region);
2103   _igvn.replace_node(_fallthroughproj, region);
2104 
2105   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
2106   mem_phi->init_req(1, memproj );
2107   mem_phi->init_req(2, mem);
2108   transform_later(mem_phi);
2109   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2110 }
2111 
2112 //------------------------------expand_macro_nodes----------------------
2113 //  Returns true if a failure occurred.
2114 bool PhaseMacroExpand::expand_macro_nodes() {
2115   if (C->macro_count() == 0)
2116     return false;
2117   // First, attempt to eliminate locks
2118   bool progress = true;
2119   while (progress) {
2120     progress = false;
2121     for (int i = C->macro_count(); i > 0; i--) {
2122       Node * n = C->macro_node(i-1);
2123       bool success = false;
2124       debug_only(int old_macro_count = C->macro_count(););
2125       if (n->is_AbstractLock()) {
2126         success = eliminate_locking_node(n->as_AbstractLock());
2127       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2128         _igvn.replace_node(n, n->in(1));
2129         success = true;
2130       }
2131       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2132       progress = progress || success;
2133     }
2134   }
2135   // Next, attempt to eliminate allocations
2136   progress = true;
2137   while (progress) {
2138     progress = false;
2139     for (int i = C->macro_count(); i > 0; i--) {
2140       Node * n = C->macro_node(i-1);
2141       bool success = false;
2142       debug_only(int old_macro_count = C->macro_count(););
2143       switch (n->class_id()) {
2144       case Node::Class_Allocate:
2145       case Node::Class_AllocateArray:
2146         success = eliminate_allocate_node(n->as_Allocate());
2147         break;
2148       case Node::Class_Lock:
2149       case Node::Class_Unlock:
2150         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2151         break;
2152       default:
2153         assert(false, "unknown node type in macro list");
2154       }
2155       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2156       progress = progress || success;
2157     }
2158   }
2159   // Make sure expansion will not cause node limit to be exceeded.
2160   // Worst case is a macro node gets expanded into about 50 nodes.
2161   // Allow 50% more for optimization.
2162   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2163     return true;
2164 
2165   // expand "macro" nodes
2166   // nodes are removed from the macro list as they are processed
2167   while (C->macro_count() > 0) {
2168     int macro_count = C->macro_count();
2169     Node * n = C->macro_node(macro_count-1);
2170     assert(n->is_macro(), "only macro nodes expected here");
2171     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2172       // node is unreachable, so don't try to expand it
2173       C->remove_macro_node(n);
2174       continue;
2175     }
2176     switch (n->class_id()) {
2177     case Node::Class_Allocate:
2178       expand_allocate(n->as_Allocate());
2179       break;
2180     case Node::Class_AllocateArray:
2181       expand_allocate_array(n->as_AllocateArray());
2182       break;
2183     case Node::Class_Lock:
2184       expand_lock_node(n->as_Lock());
2185       break;
2186     case Node::Class_Unlock:
2187       expand_unlock_node(n->as_Unlock());
2188       break;
2189     default:
2190       assert(false, "unknown node type in macro list");
2191     }
2192     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2193     if (C->failing())  return true;
2194   }
2195 
2196   _igvn.set_delay_transform(false);
2197   _igvn.optimize();
2198   return false;
2199 }