1 /*
   2  * Copyright (c) 2005, 2012, 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   // SafePointScalarObject node could be referenced several times in debug info.
  76   // Use Dict to record cloned nodes.
  77   Dict* sosn_map = new Dict(cmpkey,hashkey);
  78   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
  79     Node* old_in = oldcall->in(i);
  80     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
  81     if (old_in != NULL && old_in->is_SafePointScalarObject()) {
  82       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
  83       uint old_unique = C->unique();
  84       Node* new_in = old_sosn->clone(sosn_map);
  85       if (old_unique != C->unique()) { // New node?
  86         new_in->set_req(0, C->root()); // reset control edge
  87         new_in = transform_later(new_in); // Register new node.
  88       }
  89       old_in = new_in;
  90     }
  91     newcall->add_req(old_in);
  92   }
  93 
  94   newcall->set_jvms(oldcall->jvms());
  95   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
  96     jvms->set_map(newcall);
  97     jvms->set_locoff(jvms->locoff()+jvms_adj);
  98     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
  99     jvms->set_monoff(jvms->monoff()+jvms_adj);
 100     jvms->set_scloff(jvms->scloff()+jvms_adj);
 101     jvms->set_endoff(jvms->endoff()+jvms_adj);
 102   }
 103 }
 104 
 105 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
 106   Node* cmp;
 107   if (mask != 0) {
 108     Node* and_node = transform_later(new (C) AndXNode(word, MakeConX(mask)));
 109     cmp = transform_later(new (C) CmpXNode(and_node, MakeConX(bits)));
 110   } else {
 111     cmp = word;
 112   }
 113   Node* bol = transform_later(new (C) BoolNode(cmp, BoolTest::ne));
 114   IfNode* iff = new (C) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
 115   transform_later(iff);
 116 
 117   // Fast path taken.
 118   Node *fast_taken = transform_later( new (C) IfFalseNode(iff) );
 119 
 120   // Fast path not-taken, i.e. slow path
 121   Node *slow_taken = transform_later( new (C) IfTrueNode(iff) );
 122 
 123   if (return_fast_path) {
 124     region->init_req(edge, slow_taken); // Capture slow-control
 125     return fast_taken;
 126   } else {
 127     region->init_req(edge, fast_taken); // Capture fast-control
 128     return slow_taken;
 129   }
 130 }
 131 
 132 //--------------------copy_predefined_input_for_runtime_call--------------------
 133 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
 134   // Set fixed predefined input arguments
 135   call->init_req( TypeFunc::Control, ctrl );
 136   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
 137   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
 138   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
 139   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
 140 }
 141 
 142 //------------------------------make_slow_call---------------------------------
 143 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) {
 144 
 145   // Slow-path call
 146  CallNode *call = leaf_name
 147    ? (CallNode*)new (C) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
 148    : (CallNode*)new (C) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
 149 
 150   // Slow path call has no side-effects, uses few values
 151   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
 152   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
 153   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
 154   copy_call_debug_info(oldcall, call);
 155   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
 156   _igvn.replace_node(oldcall, call);
 157   transform_later(call);
 158 
 159   return call;
 160 }
 161 
 162 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
 163   _fallthroughproj = NULL;
 164   _fallthroughcatchproj = NULL;
 165   _ioproj_fallthrough = NULL;
 166   _ioproj_catchall = NULL;
 167   _catchallcatchproj = NULL;
 168   _memproj_fallthrough = NULL;
 169   _memproj_catchall = NULL;
 170   _resproj = NULL;
 171   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
 172     ProjNode *pn = call->fast_out(i)->as_Proj();
 173     switch (pn->_con) {
 174       case TypeFunc::Control:
 175       {
 176         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 177         _fallthroughproj = pn;
 178         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 179         const Node *cn = pn->fast_out(j);
 180         if (cn->is_Catch()) {
 181           ProjNode *cpn = NULL;
 182           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 183             cpn = cn->fast_out(k)->as_Proj();
 184             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 185             if (cpn->_con == CatchProjNode::fall_through_index)
 186               _fallthroughcatchproj = cpn;
 187             else {
 188               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 189               _catchallcatchproj = cpn;
 190             }
 191           }
 192         }
 193         break;
 194       }
 195       case TypeFunc::I_O:
 196         if (pn->_is_io_use)
 197           _ioproj_catchall = pn;
 198         else
 199           _ioproj_fallthrough = pn;
 200         break;
 201       case TypeFunc::Memory:
 202         if (pn->_is_io_use)
 203           _memproj_catchall = pn;
 204         else
 205           _memproj_fallthrough = pn;
 206         break;
 207       case TypeFunc::Parms:
 208         _resproj = pn;
 209         break;
 210       default:
 211         assert(false, "unexpected projection from allocation node.");
 212     }
 213   }
 214 
 215 }
 216 
 217 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
 218 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
 219   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
 220   if (!UseG1GC) {
 221     // vanilla/CMS post barrier
 222     Node *shift = p2x->unique_out();
 223     Node *addp = shift->unique_out();
 224     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 225       Node *mem = addp->last_out(j);
 226       if (UseCondCardMark && mem->is_Load()) {
 227         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 228         // The load is checking if the card has been written so
 229         // replace it with zero to fold the test.
 230         _igvn.replace_node(mem, intcon(0));
 231         continue;
 232       }
 233       assert(mem->is_Store(), "store required");
 234       _igvn.replace_node(mem, mem->in(MemNode::Memory));
 235     }
 236   } else {
 237     // G1 pre/post barriers
 238     assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
 239     // It could be only one user, URShift node, in Object.clone() instrinsic
 240     // but the new allocation is passed to arraycopy stub and it could not
 241     // be scalar replaced. So we don't check the case.
 242 
 243     // An other case of only one user (Xor) is when the value check for NULL
 244     // in G1 post barrier is folded after CCP so the code which used URShift
 245     // is removed.
 246 
 247     // Take Region node before eliminating post barrier since it also
 248     // eliminates CastP2X node when it has only one user.
 249     Node* this_region = p2x->in(0);
 250     assert(this_region != NULL, "");
 251 
 252     // Remove G1 post barrier.
 253 
 254     // Search for CastP2X->Xor->URShift->Cmp path which
 255     // checks if the store done to a different from the value's region.
 256     // And replace Cmp with #0 (false) to collapse G1 post barrier.
 257     Node* xorx = NULL;
 258     for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
 259       Node* u = p2x->fast_out(i);
 260       if (u->Opcode() == Op_XorX) {
 261         xorx = u;
 262         break;
 263       }
 264     }
 265     assert(xorx != NULL, "missing G1 post barrier");
 266     Node* shift = xorx->unique_out();
 267     Node* cmpx = shift->unique_out();
 268     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
 269     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
 270     "missing region check in G1 post barrier");
 271     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 272 
 273     // Remove G1 pre barrier.
 274 
 275     // Search "if (marking != 0)" check and set it to "false".
 276     // There is no G1 pre barrier if previous stored value is NULL
 277     // (for example, after initialization).
 278     if (this_region->is_Region() && this_region->req() == 3) {
 279       int ind = 1;
 280       if (!this_region->in(ind)->is_IfFalse()) {
 281         ind = 2;
 282       }
 283       if (this_region->in(ind)->is_IfFalse()) {
 284         Node* bol = this_region->in(ind)->in(0)->in(1);
 285         assert(bol->is_Bool(), "");
 286         cmpx = bol->in(1);
 287         if (bol->as_Bool()->_test._test == BoolTest::ne &&
 288             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
 289             cmpx->in(1)->is_Load()) {
 290           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
 291           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
 292                                               PtrQueue::byte_offset_of_active());
 293           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
 294               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
 295               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
 296             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 297           }
 298         }
 299       }
 300     }
 301     // Now CastP2X can be removed since it is used only on dead path
 302     // which currently still alive until igvn optimize it.
 303     assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
 304     _igvn.replace_node(p2x, top());
 305   }
 306 }
 307 
 308 // Search for a memory operation for the specified memory slice.
 309 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
 310   Node *orig_mem = mem;
 311   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 312   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
 313   while (true) {
 314     if (mem == alloc_mem || mem == start_mem ) {
 315       return mem;  // hit one of our sentinels
 316     } else if (mem->is_MergeMem()) {
 317       mem = mem->as_MergeMem()->memory_at(alias_idx);
 318     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 319       Node *in = mem->in(0);
 320       // we can safely skip over safepoints, calls, locks and membars because we
 321       // already know that the object is safe to eliminate.
 322       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 323         return in;
 324       } else if (in->is_Call()) {
 325         CallNode *call = in->as_Call();
 326         if (!call->may_modify(tinst, phase)) {
 327           mem = call->in(TypeFunc::Memory);
 328         }
 329         mem = in->in(TypeFunc::Memory);
 330       } else if (in->is_MemBar()) {
 331         mem = in->in(TypeFunc::Memory);
 332       } else {
 333         assert(false, "unexpected projection");
 334       }
 335     } else if (mem->is_Store()) {
 336       const TypePtr* atype = mem->as_Store()->adr_type();
 337       int adr_idx = Compile::current()->get_alias_index(atype);
 338       if (adr_idx == alias_idx) {
 339         assert(atype->isa_oopptr(), "address type must be oopptr");
 340         int adr_offset = atype->offset();
 341         uint adr_iid = atype->is_oopptr()->instance_id();
 342         // Array elements references have the same alias_idx
 343         // but different offset and different instance_id.
 344         if (adr_offset == offset && adr_iid == alloc->_idx)
 345           return mem;
 346       } else {
 347         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 348       }
 349       mem = mem->in(MemNode::Memory);
 350     } else if (mem->is_ClearArray()) {
 351       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
 352         // Can not bypass initialization of the instance
 353         // we are looking.
 354         debug_only(intptr_t offset;)
 355         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
 356         InitializeNode* init = alloc->as_Allocate()->initialization();
 357         // We are looking for stored value, return Initialize node
 358         // or memory edge from Allocate node.
 359         if (init != NULL)
 360           return init;
 361         else
 362           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
 363       }
 364       // Otherwise skip it (the call updated 'mem' value).
 365     } else if (mem->Opcode() == Op_SCMemProj) {
 366       mem = mem->in(0);
 367       Node* adr = NULL;
 368       if (mem->is_LoadStore()) {
 369         adr = mem->in(MemNode::Address);
 370       } else {
 371         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
 372         adr = mem->in(3); // Destination array
 373       }
 374       const TypePtr* atype = adr->bottom_type()->is_ptr();
 375       int adr_idx = Compile::current()->get_alias_index(atype);
 376       if (adr_idx == alias_idx) {
 377         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 378         return NULL;
 379       }
 380       mem = mem->in(MemNode::Memory);
 381     } else {
 382       return mem;
 383     }
 384     assert(mem != orig_mem, "dead memory loop");
 385   }
 386 }
 387 
 388 //
 389 // Given a Memory Phi, compute a value Phi containing the values from stores
 390 // on the input paths.
 391 // Note: this function is recursive, its depth is limied by the "level" argument
 392 // Returns the computed Phi, or NULL if it cannot compute it.
 393 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) {
 394   assert(mem->is_Phi(), "sanity");
 395   int alias_idx = C->get_alias_index(adr_t);
 396   int offset = adr_t->offset();
 397   int instance_id = adr_t->instance_id();
 398 
 399   // Check if an appropriate value phi already exists.
 400   Node* region = mem->in(0);
 401   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 402     Node* phi = region->fast_out(k);
 403     if (phi->is_Phi() && phi != mem &&
 404         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
 405       return phi;
 406     }
 407   }
 408   // Check if an appropriate new value phi already exists.
 409   Node* new_phi = value_phis->find(mem->_idx);
 410   if (new_phi != NULL)
 411     return new_phi;
 412 
 413   if (level <= 0) {
 414     return NULL; // Give up: phi tree too deep
 415   }
 416   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 417   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 418 
 419   uint length = mem->req();
 420   GrowableArray <Node *> values(length, length, NULL, false);
 421 
 422   // create a new Phi for the value
 423   PhiNode *phi = new (C) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
 424   transform_later(phi);
 425   value_phis->push(phi, mem->_idx);
 426 
 427   for (uint j = 1; j < length; j++) {
 428     Node *in = mem->in(j);
 429     if (in == NULL || in->is_top()) {
 430       values.at_put(j, in);
 431     } else  {
 432       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
 433       if (val == start_mem || val == alloc_mem) {
 434         // hit a sentinel, return appropriate 0 value
 435         values.at_put(j, _igvn.zerocon(ft));
 436         continue;
 437       }
 438       if (val->is_Initialize()) {
 439         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 440       }
 441       if (val == NULL) {
 442         return NULL;  // can't find a value on this path
 443       }
 444       if (val == mem) {
 445         values.at_put(j, mem);
 446       } else if (val->is_Store()) {
 447         values.at_put(j, val->in(MemNode::ValueIn));
 448       } else if(val->is_Proj() && val->in(0) == alloc) {
 449         values.at_put(j, _igvn.zerocon(ft));
 450       } else if (val->is_Phi()) {
 451         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
 452         if (val == NULL) {
 453           return NULL;
 454         }
 455         values.at_put(j, val);
 456       } else if (val->Opcode() == Op_SCMemProj) {
 457         assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
 458         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 459         return NULL;
 460       } else {
 461 #ifdef ASSERT
 462         val->dump();
 463         assert(false, "unknown node on this path");
 464 #endif
 465         return NULL;  // unknown node on this path
 466       }
 467     }
 468   }
 469   // Set Phi's inputs
 470   for (uint j = 1; j < length; j++) {
 471     if (values.at(j) == mem) {
 472       phi->init_req(j, phi);
 473     } else {
 474       phi->init_req(j, values.at(j));
 475     }
 476   }
 477   return phi;
 478 }
 479 
 480 // Search the last value stored into the object's field.
 481 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
 482   assert(adr_t->is_known_instance_field(), "instance required");
 483   int instance_id = adr_t->instance_id();
 484   assert((uint)instance_id == alloc->_idx, "wrong allocation");
 485 
 486   int alias_idx = C->get_alias_index(adr_t);
 487   int offset = adr_t->offset();
 488   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 489   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
 490   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 491   Arena *a = Thread::current()->resource_area();
 492   VectorSet visited(a);
 493 
 494 
 495   bool done = sfpt_mem == alloc_mem;
 496   Node *mem = sfpt_mem;
 497   while (!done) {
 498     if (visited.test_set(mem->_idx)) {
 499       return NULL;  // found a loop, give up
 500     }
 501     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
 502     if (mem == start_mem || mem == alloc_mem) {
 503       done = true;  // hit a sentinel, return appropriate 0 value
 504     } else if (mem->is_Initialize()) {
 505       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 506       if (mem == NULL) {
 507         done = true; // Something go wrong.
 508       } else if (mem->is_Store()) {
 509         const TypePtr* atype = mem->as_Store()->adr_type();
 510         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 511         done = true;
 512       }
 513     } else if (mem->is_Store()) {
 514       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 515       assert(atype != NULL, "address type must be oopptr");
 516       assert(C->get_alias_index(atype) == alias_idx &&
 517              atype->is_known_instance_field() && atype->offset() == offset &&
 518              atype->instance_id() == instance_id, "store is correct memory slice");
 519       done = true;
 520     } else if (mem->is_Phi()) {
 521       // try to find a phi's unique input
 522       Node *unique_input = NULL;
 523       Node *top = C->top();
 524       for (uint i = 1; i < mem->req(); i++) {
 525         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
 526         if (n == NULL || n == top || n == mem) {
 527           continue;
 528         } else if (unique_input == NULL) {
 529           unique_input = n;
 530         } else if (unique_input != n) {
 531           unique_input = top;
 532           break;
 533         }
 534       }
 535       if (unique_input != NULL && unique_input != top) {
 536         mem = unique_input;
 537       } else {
 538         done = true;
 539       }
 540     } else {
 541       assert(false, "unexpected node");
 542     }
 543   }
 544   if (mem != NULL) {
 545     if (mem == start_mem || mem == alloc_mem) {
 546       // hit a sentinel, return appropriate 0 value
 547       return _igvn.zerocon(ft);
 548     } else if (mem->is_Store()) {
 549       return mem->in(MemNode::ValueIn);
 550     } else if (mem->is_Phi()) {
 551       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 552       Node_Stack value_phis(a, 8);
 553       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
 554       if (phi != NULL) {
 555         return phi;
 556       } else {
 557         // Kill all new Phis
 558         while(value_phis.is_nonempty()) {
 559           Node* n = value_phis.node();
 560           _igvn.replace_node(n, C->top());
 561           value_phis.pop();
 562         }
 563       }
 564     }
 565   }
 566   // Something go wrong.
 567   return NULL;
 568 }
 569 
 570 // Check the possibility of scalar replacement.
 571 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 572   //  Scan the uses of the allocation to check for anything that would
 573   //  prevent us from eliminating it.
 574   NOT_PRODUCT( const char* fail_eliminate = NULL; )
 575   DEBUG_ONLY( Node* disq_node = NULL; )
 576   bool  can_eliminate = true;
 577 
 578   Node* res = alloc->result_cast();
 579   const TypeOopPtr* res_type = NULL;
 580   if (res == NULL) {
 581     // All users were eliminated.
 582   } else if (!res->is_CheckCastPP()) {
 583     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 584     can_eliminate = false;
 585   } else {
 586     res_type = _igvn.type(res)->isa_oopptr();
 587     if (res_type == NULL) {
 588       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 589       can_eliminate = false;
 590     } else if (res_type->isa_aryptr()) {
 591       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 592       if (length < 0) {
 593         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 594         can_eliminate = false;
 595       }
 596     }
 597   }
 598 
 599   if (can_eliminate && res != NULL) {
 600     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
 601                                j < jmax && can_eliminate; j++) {
 602       Node* use = res->fast_out(j);
 603 
 604       if (use->is_AddP()) {
 605         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
 606         int offset = addp_type->offset();
 607 
 608         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 609           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
 610           can_eliminate = false;
 611           break;
 612         }
 613         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 614                                    k < kmax && can_eliminate; k++) {
 615           Node* n = use->fast_out(k);
 616           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
 617             DEBUG_ONLY(disq_node = n;)
 618             if (n->is_Load() || n->is_LoadStore()) {
 619               NOT_PRODUCT(fail_eliminate = "Field load";)
 620             } else {
 621               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
 622             }
 623             can_eliminate = false;
 624           }
 625         }
 626       } else if (use->is_SafePoint()) {
 627         SafePointNode* sfpt = use->as_SafePoint();
 628         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 629           // Object is passed as argument.
 630           DEBUG_ONLY(disq_node = use;)
 631           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 632           can_eliminate = false;
 633         }
 634         Node* sfptMem = sfpt->memory();
 635         if (sfptMem == NULL || sfptMem->is_top()) {
 636           DEBUG_ONLY(disq_node = use;)
 637           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
 638           can_eliminate = false;
 639         } else {
 640           safepoints.append_if_missing(sfpt);
 641         }
 642       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 643         if (use->is_Phi()) {
 644           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 645             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 646           } else {
 647             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 648           }
 649           DEBUG_ONLY(disq_node = use;)
 650         } else {
 651           if (use->Opcode() == Op_Return) {
 652             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 653           }else {
 654             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 655           }
 656           DEBUG_ONLY(disq_node = use;)
 657         }
 658         can_eliminate = false;
 659       }
 660     }
 661   }
 662 
 663 #ifndef PRODUCT
 664   if (PrintEliminateAllocations) {
 665     if (can_eliminate) {
 666       tty->print("Scalar ");
 667       if (res == NULL)
 668         alloc->dump();
 669       else
 670         res->dump();
 671     } else if (alloc->_is_scalar_replaceable) {
 672       tty->print("NotScalar (%s)", fail_eliminate);
 673       if (res == NULL)
 674         alloc->dump();
 675       else
 676         res->dump();
 677 #ifdef ASSERT
 678       if (disq_node != NULL) {
 679           tty->print("  >>>> ");
 680           disq_node->dump();
 681       }
 682 #endif /*ASSERT*/
 683     }
 684   }
 685 #endif
 686   return can_eliminate;
 687 }
 688 
 689 // Do scalar replacement.
 690 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 691   GrowableArray <SafePointNode *> safepoints_done;
 692 
 693   ciKlass* klass = NULL;
 694   ciInstanceKlass* iklass = NULL;
 695   int nfields = 0;
 696   int array_base;
 697   int element_size;
 698   BasicType basic_elem_type;
 699   ciType* elem_type;
 700 
 701   Node* res = alloc->result_cast();
 702   const TypeOopPtr* res_type = NULL;
 703   if (res != NULL) { // Could be NULL when there are no users
 704     res_type = _igvn.type(res)->isa_oopptr();
 705   }
 706 
 707   if (res != NULL) {
 708     klass = res_type->klass();
 709     if (res_type->isa_instptr()) {
 710       // find the fields of the class which will be needed for safepoint debug information
 711       assert(klass->is_instance_klass(), "must be an instance klass.");
 712       iklass = klass->as_instance_klass();
 713       nfields = iklass->nof_nonstatic_fields();
 714     } else {
 715       // find the array's elements which will be needed for safepoint debug information
 716       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 717       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
 718       elem_type = klass->as_array_klass()->element_type();
 719       basic_elem_type = elem_type->basic_type();
 720       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 721       element_size = type2aelembytes(basic_elem_type);
 722     }
 723   }
 724   //
 725   // Process the safepoint uses
 726   //
 727   while (safepoints.length() > 0) {
 728     SafePointNode* sfpt = safepoints.pop();
 729     Node* mem = sfpt->memory();
 730     assert(sfpt->jvms() != NULL, "missed JVMS");
 731     // Fields of scalar objs are referenced only at the end
 732     // of regular debuginfo at the last (youngest) JVMS.
 733     // Record relative start index.
 734     uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
 735     SafePointScalarObjectNode* sobj = new (C) SafePointScalarObjectNode(res_type,
 736 #ifdef ASSERT
 737                                                  alloc,
 738 #endif
 739                                                  first_ind, nfields);
 740     sobj->init_req(0, C->root());
 741     transform_later(sobj);
 742 
 743     // Scan object's fields adding an input to the safepoint for each field.
 744     for (int j = 0; j < nfields; j++) {
 745       intptr_t offset;
 746       ciField* field = NULL;
 747       if (iklass != NULL) {
 748         field = iklass->nonstatic_field_at(j);
 749         offset = field->offset();
 750         elem_type = field->type();
 751         basic_elem_type = field->layout_type();
 752       } else {
 753         offset = array_base + j * (intptr_t)element_size;
 754       }
 755 
 756       const Type *field_type;
 757       // The next code is taken from Parse::do_get_xxx().
 758       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
 759         if (!elem_type->is_loaded()) {
 760           field_type = TypeInstPtr::BOTTOM;
 761         } else if (field != NULL && field->is_constant() && field->is_static()) {
 762           // This can happen if the constant oop is non-perm.
 763           ciObject* con = field->constant_value().as_object();
 764           // Do not "join" in the previous type; it doesn't add value,
 765           // and may yield a vacuous result if the field is of interface type.
 766           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 767           assert(field_type != NULL, "field singleton type must be consistent");
 768         } else {
 769           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 770         }
 771         if (UseCompressedOops) {
 772           field_type = field_type->make_narrowoop();
 773           basic_elem_type = T_NARROWOOP;
 774         }
 775       } else {
 776         field_type = Type::get_const_basic_type(basic_elem_type);
 777       }
 778 
 779       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
 780 
 781       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
 782       if (field_val == NULL) {
 783         // We weren't able to find a value for this field,
 784         // give up on eliminating this allocation.
 785 
 786         // Remove any extra entries we added to the safepoint.
 787         uint last = sfpt->req() - 1;
 788         for (int k = 0;  k < j; k++) {
 789           sfpt->del_req(last--);
 790         }
 791         // rollback processed safepoints
 792         while (safepoints_done.length() > 0) {
 793           SafePointNode* sfpt_done = safepoints_done.pop();
 794           // remove any extra entries we added to the safepoint
 795           last = sfpt_done->req() - 1;
 796           for (int k = 0;  k < nfields; k++) {
 797             sfpt_done->del_req(last--);
 798           }
 799           JVMState *jvms = sfpt_done->jvms();
 800           jvms->set_endoff(sfpt_done->req());
 801           // Now make a pass over the debug information replacing any references
 802           // to SafePointScalarObjectNode with the allocated object.
 803           int start = jvms->debug_start();
 804           int end   = jvms->debug_end();
 805           for (int i = start; i < end; i++) {
 806             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 807               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 808               if (scobj->first_index(jvms) == sfpt_done->req() &&
 809                   scobj->n_fields() == (uint)nfields) {
 810                 assert(scobj->alloc() == alloc, "sanity");
 811                 sfpt_done->set_req(i, res);
 812               }
 813             }
 814           }
 815         }
 816 #ifndef PRODUCT
 817         if (PrintEliminateAllocations) {
 818           if (field != NULL) {
 819             tty->print("=== At SafePoint node %d can't find value of Field: ",
 820                        sfpt->_idx);
 821             field->print();
 822             int field_idx = C->get_alias_index(field_addr_type);
 823             tty->print(" (alias_idx=%d)", field_idx);
 824           } else { // Array's element
 825             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
 826                        sfpt->_idx, j);
 827           }
 828           tty->print(", which prevents elimination of: ");
 829           if (res == NULL)
 830             alloc->dump();
 831           else
 832             res->dump();
 833         }
 834 #endif
 835         return false;
 836       }
 837       if (UseCompressedOops && field_type->isa_narrowoop()) {
 838         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
 839         // to be able scalar replace the allocation.
 840         if (field_val->is_EncodeP()) {
 841           field_val = field_val->in(1);
 842         } else {
 843           field_val = transform_later(new (C) DecodeNNode(field_val, field_val->get_ptr_type()));
 844         }
 845       }
 846       sfpt->add_req(field_val);
 847     }
 848     JVMState *jvms = sfpt->jvms();
 849     jvms->set_endoff(sfpt->req());
 850     // Now make a pass over the debug information replacing any references
 851     // to the allocated object with "sobj"
 852     int start = jvms->debug_start();
 853     int end   = jvms->debug_end();
 854     sfpt->replace_edges_in_range(res, sobj, start, end);
 855     safepoints_done.append_if_missing(sfpt); // keep it for rollback
 856   }
 857   return true;
 858 }
 859 
 860 // Process users of eliminated allocation.
 861 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
 862   Node* res = alloc->result_cast();
 863   if (res != NULL) {
 864     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
 865       Node *use = res->last_out(j);
 866       uint oc1 = res->outcnt();
 867 
 868       if (use->is_AddP()) {
 869         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
 870           Node *n = use->last_out(k);
 871           uint oc2 = use->outcnt();
 872           if (n->is_Store()) {
 873 #ifdef ASSERT
 874             // Verify that there is no dependent MemBarVolatile nodes,
 875             // they should be removed during IGVN, see MemBarNode::Ideal().
 876             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
 877                                        p < pmax; p++) {
 878               Node* mb = n->fast_out(p);
 879               assert(mb->is_Initialize() || !mb->is_MemBar() ||
 880                      mb->req() <= MemBarNode::Precedent ||
 881                      mb->in(MemBarNode::Precedent) != n,
 882                      "MemBarVolatile should be eliminated for non-escaping object");
 883             }
 884 #endif
 885             _igvn.replace_node(n, n->in(MemNode::Memory));
 886           } else {
 887             eliminate_card_mark(n);
 888           }
 889           k -= (oc2 - use->outcnt());
 890         }
 891       } else {
 892         eliminate_card_mark(use);
 893       }
 894       j -= (oc1 - res->outcnt());
 895     }
 896     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
 897     _igvn.remove_dead_node(res);
 898   }
 899 
 900   //
 901   // Process other users of allocation's projections
 902   //
 903   if (_resproj != NULL && _resproj->outcnt() != 0) {
 904     // First disconnect stores captured by Initialize node.
 905     // If Initialize node is eliminated first in the following code,
 906     // it will kill such stores and DUIterator_Last will assert.
 907     for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax);  j < jmax; j++) {
 908       Node *use = _resproj->fast_out(j);
 909       if (use->is_AddP()) {
 910         // raw memory addresses used only by the initialization
 911         _igvn.replace_node(use, C->top());
 912         --j; --jmax;
 913       }
 914     }
 915     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
 916       Node *use = _resproj->last_out(j);
 917       uint oc1 = _resproj->outcnt();
 918       if (use->is_Initialize()) {
 919         // Eliminate Initialize node.
 920         InitializeNode *init = use->as_Initialize();
 921         assert(init->outcnt() <= 2, "only a control and memory projection expected");
 922         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
 923         if (ctrl_proj != NULL) {
 924            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
 925           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
 926         }
 927         Node *mem_proj = init->proj_out(TypeFunc::Memory);
 928         if (mem_proj != NULL) {
 929           Node *mem = init->in(TypeFunc::Memory);
 930 #ifdef ASSERT
 931           if (mem->is_MergeMem()) {
 932             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
 933           } else {
 934             assert(mem == _memproj_fallthrough, "allocation memory projection");
 935           }
 936 #endif
 937           _igvn.replace_node(mem_proj, mem);
 938         }
 939       } else  {
 940         assert(false, "only Initialize or AddP expected");
 941       }
 942       j -= (oc1 - _resproj->outcnt());
 943     }
 944   }
 945   if (_fallthroughcatchproj != NULL) {
 946     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
 947   }
 948   if (_memproj_fallthrough != NULL) {
 949     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
 950   }
 951   if (_memproj_catchall != NULL) {
 952     _igvn.replace_node(_memproj_catchall, C->top());
 953   }
 954   if (_ioproj_fallthrough != NULL) {
 955     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
 956   }
 957   if (_ioproj_catchall != NULL) {
 958     _igvn.replace_node(_ioproj_catchall, C->top());
 959   }
 960   if (_catchallcatchproj != NULL) {
 961     _igvn.replace_node(_catchallcatchproj, C->top());
 962   }
 963 }
 964 
 965 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
 966   if (!EliminateAllocations || !alloc->_is_non_escaping) {
 967     return false;
 968   }
 969   Node* klass = alloc->in(AllocateNode::KlassNode);
 970   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
 971   Node* res = alloc->result_cast();
 972   // Eliminate boxing allocations which are not used
 973   // regardless scalar replacable status.
 974   bool boxing_alloc = C->eliminate_boxing() &&
 975                       tklass->klass()->is_instance_klass()  &&
 976                       tklass->klass()->as_instance_klass()->is_box_klass();
 977   if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
 978     return false;
 979   }
 980 
 981   extract_call_projections(alloc);
 982 
 983   GrowableArray <SafePointNode *> safepoints;
 984   if (!can_eliminate_allocation(alloc, safepoints)) {
 985     return false;
 986   }
 987 
 988   if (!alloc->_is_scalar_replaceable) {
 989     assert(res == NULL, "sanity");
 990     // We can only eliminate allocation if all debug info references
 991     // are already replaced with SafePointScalarObject because
 992     // we can't search for a fields value without instance_id.
 993     if (safepoints.length() > 0) {
 994       return false;
 995     }
 996   }
 997 
 998   if (!scalar_replacement(alloc, safepoints)) {
 999     return false;
1000   }
1001 
1002   CompileLog* log = C->log();
1003   if (log != NULL) {
1004     log->head("eliminate_allocation type='%d'",
1005               log->identify(tklass->klass()));
1006     JVMState* p = alloc->jvms();
1007     while (p != NULL) {
1008       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1009       p = p->caller();
1010     }
1011     log->tail("eliminate_allocation");
1012   }
1013 
1014   process_users_of_allocation(alloc);
1015 
1016 #ifndef PRODUCT
1017   if (PrintEliminateAllocations) {
1018     if (alloc->is_AllocateArray())
1019       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1020     else
1021       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1022   }
1023 #endif
1024 
1025   return true;
1026 }
1027 
1028 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1029   // EA should remove all uses of non-escaping boxing node.
1030   if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
1031     return false;
1032   }
1033 
1034   extract_call_projections(boxing);
1035 
1036   const TypeTuple* r = boxing->tf()->range();
1037   assert(r->cnt() > TypeFunc::Parms, "sanity");
1038   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1039   assert(t != NULL, "sanity");
1040 
1041   CompileLog* log = C->log();
1042   if (log != NULL) {
1043     log->head("eliminate_boxing type='%d'",
1044               log->identify(t->klass()));
1045     JVMState* p = boxing->jvms();
1046     while (p != NULL) {
1047       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1048       p = p->caller();
1049     }
1050     log->tail("eliminate_boxing");
1051   }
1052 
1053   process_users_of_allocation(boxing);
1054 
1055 #ifndef PRODUCT
1056   if (PrintEliminateAllocations) {
1057     tty->print("++++ Eliminated: %d ", boxing->_idx);
1058     boxing->method()->print_short_name(tty);
1059     tty->cr();
1060   }
1061 #endif
1062 
1063   return true;
1064 }
1065 
1066 //---------------------------set_eden_pointers-------------------------
1067 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1068   if (UseTLAB) {                // Private allocation: load from TLS
1069     Node* thread = transform_later(new (C) ThreadLocalNode());
1070     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1071     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1072     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1073     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1074   } else {                      // Shared allocation: load from globals
1075     CollectedHeap* ch = Universe::heap();
1076     address top_adr = (address)ch->top_addr();
1077     address end_adr = (address)ch->end_addr();
1078     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1079     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1080   }
1081 }
1082 
1083 
1084 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1085   Node* adr = basic_plus_adr(base, offset);
1086   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1087   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, LoadNode::unordered);
1088   transform_later(value);
1089   return value;
1090 }
1091 
1092 
1093 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1094   Node* adr = basic_plus_adr(base, offset);
1095   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, StoreNode::unordered);
1096   transform_later(mem);
1097   return mem;
1098 }
1099 
1100 //=============================================================================
1101 //
1102 //                              A L L O C A T I O N
1103 //
1104 // Allocation attempts to be fast in the case of frequent small objects.
1105 // It breaks down like this:
1106 //
1107 // 1) Size in doublewords is computed.  This is a constant for objects and
1108 // variable for most arrays.  Doubleword units are used to avoid size
1109 // overflow of huge doubleword arrays.  We need doublewords in the end for
1110 // rounding.
1111 //
1112 // 2) Size is checked for being 'too large'.  Too-large allocations will go
1113 // the slow path into the VM.  The slow path can throw any required
1114 // exceptions, and does all the special checks for very large arrays.  The
1115 // size test can constant-fold away for objects.  For objects with
1116 // finalizers it constant-folds the otherway: you always go slow with
1117 // finalizers.
1118 //
1119 // 3) If NOT using TLABs, this is the contended loop-back point.
1120 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
1121 //
1122 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
1123 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
1124 // "size*8" we always enter the VM, where "largish" is a constant picked small
1125 // enough that there's always space between the eden max and 4Gig (old space is
1126 // there so it's quite large) and large enough that the cost of entering the VM
1127 // is dwarfed by the cost to initialize the space.
1128 //
1129 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1130 // down.  If contended, repeat at step 3.  If using TLABs normal-store
1131 // adjusted heap top back down; there is no contention.
1132 //
1133 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
1134 // fields.
1135 //
1136 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1137 // oop flavor.
1138 //
1139 //=============================================================================
1140 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1141 // Allocations bigger than this always go the slow route.
1142 // This value must be small enough that allocation attempts that need to
1143 // trigger exceptions go the slow route.  Also, it must be small enough so
1144 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1145 //=============================================================================j//
1146 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1147 // The allocator will coalesce int->oop copies away.  See comment in
1148 // coalesce.cpp about how this works.  It depends critically on the exact
1149 // code shape produced here, so if you are changing this code shape
1150 // make sure the GC info for the heap-top is correct in and around the
1151 // slow-path call.
1152 //
1153 
1154 void PhaseMacroExpand::expand_allocate_common(
1155             AllocateNode* alloc, // allocation node to be expanded
1156             Node* length,  // array length for an array allocation
1157             const TypeFunc* slow_call_type, // Type of slow call
1158             address slow_call_address  // Address of slow call
1159     )
1160 {
1161 
1162   Node* ctrl = alloc->in(TypeFunc::Control);
1163   Node* mem  = alloc->in(TypeFunc::Memory);
1164   Node* i_o  = alloc->in(TypeFunc::I_O);
1165   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
1166   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
1167   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1168 
1169   assert(ctrl != NULL, "must have control");
1170   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1171   // they will not be used if "always_slow" is set
1172   enum { slow_result_path = 1, fast_result_path = 2 };
1173   Node *result_region;
1174   Node *result_phi_rawmem;
1175   Node *result_phi_rawoop;
1176   Node *result_phi_i_o;
1177 
1178   // The initial slow comparison is a size check, the comparison
1179   // we want to do is a BoolTest::gt
1180   bool always_slow = false;
1181   int tv = _igvn.find_int_con(initial_slow_test, -1);
1182   if (tv >= 0) {
1183     always_slow = (tv == 1);
1184     initial_slow_test = NULL;
1185   } else {
1186     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1187   }
1188 
1189   if (C->env()->dtrace_alloc_probes() ||
1190       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
1191                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
1192     // Force slow-path allocation
1193     always_slow = true;
1194     initial_slow_test = NULL;
1195   }
1196 
1197 
1198   enum { too_big_or_final_path = 1, need_gc_path = 2 };
1199   Node *slow_region = NULL;
1200   Node *toobig_false = ctrl;
1201 
1202   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1203   // generate the initial test if necessary
1204   if (initial_slow_test != NULL ) {
1205     slow_region = new (C) RegionNode(3);
1206 
1207     // Now make the initial failure test.  Usually a too-big test but
1208     // might be a TRUE for finalizers or a fancy class check for
1209     // newInstance0.
1210     IfNode *toobig_iff = new (C) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1211     transform_later(toobig_iff);
1212     // Plug the failing-too-big test into the slow-path region
1213     Node *toobig_true = new (C) IfTrueNode( toobig_iff );
1214     transform_later(toobig_true);
1215     slow_region    ->init_req( too_big_or_final_path, toobig_true );
1216     toobig_false = new (C) IfFalseNode( toobig_iff );
1217     transform_later(toobig_false);
1218   } else {         // No initial test, just fall into next case
1219     toobig_false = ctrl;
1220     debug_only(slow_region = NodeSentinel);
1221   }
1222 
1223   Node *slow_mem = mem;  // save the current memory state for slow path
1224   // generate the fast allocation code unless we know that the initial test will always go slow
1225   if (!always_slow) {
1226     // Fast path modifies only raw memory.
1227     if (mem->is_MergeMem()) {
1228       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1229     }
1230 
1231     Node* eden_top_adr;
1232     Node* eden_end_adr;
1233 
1234     set_eden_pointers(eden_top_adr, eden_end_adr);
1235 
1236     // Load Eden::end.  Loop invariant and hoisted.
1237     //
1238     // Note: We set the control input on "eden_end" and "old_eden_top" when using
1239     //       a TLAB to work around a bug where these values were being moved across
1240     //       a safepoint.  These are not oops, so they cannot be include in the oop
1241     //       map, but they can be changed by a GC.   The proper way to fix this would
1242     //       be to set the raw memory state when generating a  SafepointNode.  However
1243     //       this will require extensive changes to the loop optimization in order to
1244     //       prevent a degradation of the optimization.
1245     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
1246     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1247 
1248     // allocate the Region and Phi nodes for the result
1249     result_region = new (C) RegionNode(3);
1250     result_phi_rawmem = new (C) PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1251     result_phi_rawoop = new (C) PhiNode(result_region, TypeRawPtr::BOTTOM);
1252     result_phi_i_o    = new (C) PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1253 
1254     // We need a Region for the loop-back contended case.
1255     enum { fall_in_path = 1, contended_loopback_path = 2 };
1256     Node *contended_region;
1257     Node *contended_phi_rawmem;
1258     if (UseTLAB) {
1259       contended_region = toobig_false;
1260       contended_phi_rawmem = mem;
1261     } else {
1262       contended_region = new (C) RegionNode(3);
1263       contended_phi_rawmem = new (C) PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1264       // Now handle the passing-too-big test.  We fall into the contended
1265       // loop-back merge point.
1266       contended_region    ->init_req(fall_in_path, toobig_false);
1267       contended_phi_rawmem->init_req(fall_in_path, mem);
1268       transform_later(contended_region);
1269       transform_later(contended_phi_rawmem);
1270     }
1271 
1272     // Load(-locked) the heap top.
1273     // See note above concerning the control input when using a TLAB
1274     Node *old_eden_top = UseTLAB
1275       ? new (C) LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, LoadNode::unordered)
1276       : new (C) LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr, LoadNode::acquire);
1277 
1278     transform_later(old_eden_top);
1279     // Add to heap top to get a new heap top
1280     Node *new_eden_top = new (C) AddPNode(top(), old_eden_top, size_in_bytes);
1281     transform_later(new_eden_top);
1282     // Check for needing a GC; compare against heap end
1283     Node *needgc_cmp = new (C) CmpPNode(new_eden_top, eden_end);
1284     transform_later(needgc_cmp);
1285     Node *needgc_bol = new (C) BoolNode(needgc_cmp, BoolTest::ge);
1286     transform_later(needgc_bol);
1287     IfNode *needgc_iff = new (C) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1288     transform_later(needgc_iff);
1289 
1290     // Plug the failing-heap-space-need-gc test into the slow-path region
1291     Node *needgc_true = new (C) IfTrueNode(needgc_iff);
1292     transform_later(needgc_true);
1293     if (initial_slow_test) {
1294       slow_region->init_req(need_gc_path, needgc_true);
1295       // This completes all paths into the slow merge point
1296       transform_later(slow_region);
1297     } else {                      // No initial slow path needed!
1298       // Just fall from the need-GC path straight into the VM call.
1299       slow_region = needgc_true;
1300     }
1301     // No need for a GC.  Setup for the Store-Conditional
1302     Node *needgc_false = new (C) IfFalseNode(needgc_iff);
1303     transform_later(needgc_false);
1304 
1305     // Grab regular I/O before optional prefetch may change it.
1306     // Slow-path does no I/O so just set it to the original I/O.
1307     result_phi_i_o->init_req(slow_result_path, i_o);
1308 
1309     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1310                               old_eden_top, new_eden_top, length);
1311 
1312     // Name successful fast-path variables
1313     Node* fast_oop = old_eden_top;
1314     Node* fast_oop_ctrl;
1315     Node* fast_oop_rawmem;
1316 
1317     // Store (-conditional) the modified eden top back down.
1318     // StorePConditional produces flags for a test PLUS a modified raw
1319     // memory state.
1320     if (UseTLAB) {
1321       Node* store_eden_top =
1322         new (C) StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1323                               TypeRawPtr::BOTTOM, new_eden_top, StoreNode::unordered);
1324       transform_later(store_eden_top);
1325       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1326       fast_oop_rawmem = store_eden_top;
1327     } else {
1328       Node* store_eden_top =
1329         new (C) StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1330                                          new_eden_top, fast_oop/*old_eden_top*/);
1331       transform_later(store_eden_top);
1332       Node *contention_check = new (C) BoolNode(store_eden_top, BoolTest::ne);
1333       transform_later(contention_check);
1334       store_eden_top = new (C) SCMemProjNode(store_eden_top);
1335       transform_later(store_eden_top);
1336 
1337       // If not using TLABs, check to see if there was contention.
1338       IfNode *contention_iff = new (C) IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1339       transform_later(contention_iff);
1340       Node *contention_true = new (C) IfTrueNode(contention_iff);
1341       transform_later(contention_true);
1342       // If contention, loopback and try again.
1343       contended_region->init_req(contended_loopback_path, contention_true);
1344       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1345 
1346       // Fast-path succeeded with no contention!
1347       Node *contention_false = new (C) IfFalseNode(contention_iff);
1348       transform_later(contention_false);
1349       fast_oop_ctrl = contention_false;
1350 
1351       // Bump total allocated bytes for this thread
1352       Node* thread = new (C) ThreadLocalNode();
1353       transform_later(thread);
1354       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1355                                              in_bytes(JavaThread::allocated_bytes_offset()));
1356       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1357                                     0, TypeLong::LONG, T_LONG);
1358 #ifdef _LP64
1359       Node* alloc_size = size_in_bytes;
1360 #else
1361       Node* alloc_size = new (C) ConvI2LNode(size_in_bytes);
1362       transform_later(alloc_size);
1363 #endif
1364       Node* new_alloc_bytes = new (C) AddLNode(alloc_bytes, alloc_size);
1365       transform_later(new_alloc_bytes);
1366       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1367                                    0, new_alloc_bytes, T_LONG);
1368     }
1369 
1370     InitializeNode* init = alloc->initialization();
1371     fast_oop_rawmem = initialize_object(alloc,
1372                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1373                                         klass_node, length, size_in_bytes);
1374 
1375     // If initialization is performed by an array copy, any required
1376     // MemBarStoreStore was already added. If the object does not
1377     // escape no need for a MemBarStoreStore. Otherwise we need a
1378     // MemBarStoreStore so that stores that initialize this object
1379     // can't be reordered with a subsequent store that makes this
1380     // object accessible by other threads.
1381     if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
1382       if (init == NULL || init->req() < InitializeNode::RawStores) {
1383         // No InitializeNode or no stores captured by zeroing
1384         // elimination. Simply add the MemBarStoreStore after object
1385         // initialization.
1386         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1387         transform_later(mb);
1388 
1389         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1390         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1391         fast_oop_ctrl = new (C) ProjNode(mb,TypeFunc::Control);
1392         transform_later(fast_oop_ctrl);
1393         fast_oop_rawmem = new (C) ProjNode(mb,TypeFunc::Memory);
1394         transform_later(fast_oop_rawmem);
1395       } else {
1396         // Add the MemBarStoreStore after the InitializeNode so that
1397         // all stores performing the initialization that were moved
1398         // before the InitializeNode happen before the storestore
1399         // barrier.
1400 
1401         Node* init_ctrl = init->proj_out(TypeFunc::Control);
1402         Node* init_mem = init->proj_out(TypeFunc::Memory);
1403 
1404         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1405         transform_later(mb);
1406 
1407         Node* ctrl = new (C) ProjNode(init,TypeFunc::Control);
1408         transform_later(ctrl);
1409         Node* mem = new (C) ProjNode(init,TypeFunc::Memory);
1410         transform_later(mem);
1411 
1412         // The MemBarStoreStore depends on control and memory coming
1413         // from the InitializeNode
1414         mb->init_req(TypeFunc::Memory, mem);
1415         mb->init_req(TypeFunc::Control, ctrl);
1416 
1417         ctrl = new (C) ProjNode(mb,TypeFunc::Control);
1418         transform_later(ctrl);
1419         mem = new (C) ProjNode(mb,TypeFunc::Memory);
1420         transform_later(mem);
1421 
1422         // All nodes that depended on the InitializeNode for control
1423         // and memory must now depend on the MemBarNode that itself
1424         // depends on the InitializeNode
1425         _igvn.replace_node(init_ctrl, ctrl);
1426         _igvn.replace_node(init_mem, mem);
1427       }
1428     }
1429 
1430     if (C->env()->dtrace_extended_probes()) {
1431       // Slow-path call
1432       int size = TypeFunc::Parms + 2;
1433       CallLeafNode *call = new (C) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1434                                                 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1435                                                 "dtrace_object_alloc",
1436                                                 TypeRawPtr::BOTTOM);
1437 
1438       // Get base of thread-local storage area
1439       Node* thread = new (C) ThreadLocalNode();
1440       transform_later(thread);
1441 
1442       call->init_req(TypeFunc::Parms+0, thread);
1443       call->init_req(TypeFunc::Parms+1, fast_oop);
1444       call->init_req(TypeFunc::Control, fast_oop_ctrl);
1445       call->init_req(TypeFunc::I_O    , top()); // does no i/o
1446       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1447       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1448       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1449       transform_later(call);
1450       fast_oop_ctrl = new (C) ProjNode(call,TypeFunc::Control);
1451       transform_later(fast_oop_ctrl);
1452       fast_oop_rawmem = new (C) ProjNode(call,TypeFunc::Memory);
1453       transform_later(fast_oop_rawmem);
1454     }
1455 
1456     // Plug in the successful fast-path into the result merge point
1457     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
1458     result_phi_rawoop->init_req(fast_result_path, fast_oop);
1459     result_phi_i_o   ->init_req(fast_result_path, i_o);
1460     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1461   } else {
1462     slow_region = ctrl;
1463     result_phi_i_o = i_o; // Rename it to use in the following code.
1464   }
1465 
1466   // Generate slow-path call
1467   CallNode *call = new (C) CallStaticJavaNode(slow_call_type, slow_call_address,
1468                                OptoRuntime::stub_name(slow_call_address),
1469                                alloc->jvms()->bci(),
1470                                TypePtr::BOTTOM);
1471   call->init_req( TypeFunc::Control, slow_region );
1472   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
1473   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1474   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1475   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1476 
1477   call->init_req(TypeFunc::Parms+0, klass_node);
1478   if (length != NULL) {
1479     call->init_req(TypeFunc::Parms+1, length);
1480   }
1481 
1482   // Copy debug information and adjust JVMState information, then replace
1483   // allocate node with the call
1484   copy_call_debug_info((CallNode *) alloc,  call);
1485   if (!always_slow) {
1486     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1487   } else {
1488     // Hook i_o projection to avoid its elimination during allocation
1489     // replacement (when only a slow call is generated).
1490     call->set_req(TypeFunc::I_O, result_phi_i_o);
1491   }
1492   _igvn.replace_node(alloc, call);
1493   transform_later(call);
1494 
1495   // Identify the output projections from the allocate node and
1496   // adjust any references to them.
1497   // The control and io projections look like:
1498   //
1499   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1500   //  Allocate                   Catch
1501   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1502   //
1503   //  We are interested in the CatchProj nodes.
1504   //
1505   extract_call_projections(call);
1506 
1507   // An allocate node has separate memory projections for the uses on
1508   // the control and i_o paths. Replace the control memory projection with
1509   // result_phi_rawmem (unless we are only generating a slow call when
1510   // both memory projections are combined)
1511   if (!always_slow && _memproj_fallthrough != NULL) {
1512     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1513       Node *use = _memproj_fallthrough->fast_out(i);
1514       _igvn.rehash_node_delayed(use);
1515       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1516       // back up iterator
1517       --i;
1518     }
1519   }
1520   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1521   // _memproj_catchall so we end up with a call that has only 1 memory projection.
1522   if (_memproj_catchall != NULL ) {
1523     if (_memproj_fallthrough == NULL) {
1524       _memproj_fallthrough = new (C) ProjNode(call, TypeFunc::Memory);
1525       transform_later(_memproj_fallthrough);
1526     }
1527     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1528       Node *use = _memproj_catchall->fast_out(i);
1529       _igvn.rehash_node_delayed(use);
1530       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1531       // back up iterator
1532       --i;
1533     }
1534     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1535     _igvn.remove_dead_node(_memproj_catchall);
1536   }
1537 
1538   // An allocate node has separate i_o projections for the uses on the control
1539   // and i_o paths. Always replace the control i_o projection with result i_o
1540   // otherwise incoming i_o become dead when only a slow call is generated
1541   // (it is different from memory projections where both projections are
1542   // combined in such case).
1543   if (_ioproj_fallthrough != NULL) {
1544     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1545       Node *use = _ioproj_fallthrough->fast_out(i);
1546       _igvn.rehash_node_delayed(use);
1547       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1548       // back up iterator
1549       --i;
1550     }
1551   }
1552   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1553   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1554   if (_ioproj_catchall != NULL ) {
1555     if (_ioproj_fallthrough == NULL) {
1556       _ioproj_fallthrough = new (C) ProjNode(call, TypeFunc::I_O);
1557       transform_later(_ioproj_fallthrough);
1558     }
1559     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1560       Node *use = _ioproj_catchall->fast_out(i);
1561       _igvn.rehash_node_delayed(use);
1562       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1563       // back up iterator
1564       --i;
1565     }
1566     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1567     _igvn.remove_dead_node(_ioproj_catchall);
1568   }
1569 
1570   // if we generated only a slow call, we are done
1571   if (always_slow) {
1572     // Now we can unhook i_o.
1573     if (result_phi_i_o->outcnt() > 1) {
1574       call->set_req(TypeFunc::I_O, top());
1575     } else {
1576       assert(result_phi_i_o->unique_ctrl_out() == call, "");
1577       // Case of new array with negative size known during compilation.
1578       // AllocateArrayNode::Ideal() optimization disconnect unreachable
1579       // following code since call to runtime will throw exception.
1580       // As result there will be no users of i_o after the call.
1581       // Leave i_o attached to this call to avoid problems in preceding graph.
1582     }
1583     return;
1584   }
1585 
1586 
1587   if (_fallthroughcatchproj != NULL) {
1588     ctrl = _fallthroughcatchproj->clone();
1589     transform_later(ctrl);
1590     _igvn.replace_node(_fallthroughcatchproj, result_region);
1591   } else {
1592     ctrl = top();
1593   }
1594   Node *slow_result;
1595   if (_resproj == NULL) {
1596     // no uses of the allocation result
1597     slow_result = top();
1598   } else {
1599     slow_result = _resproj->clone();
1600     transform_later(slow_result);
1601     _igvn.replace_node(_resproj, result_phi_rawoop);
1602   }
1603 
1604   // Plug slow-path into result merge point
1605   result_region    ->init_req( slow_result_path, ctrl );
1606   result_phi_rawoop->init_req( slow_result_path, slow_result);
1607   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1608   transform_later(result_region);
1609   transform_later(result_phi_rawoop);
1610   transform_later(result_phi_rawmem);
1611   transform_later(result_phi_i_o);
1612   // This completes all paths into the result merge point
1613 }
1614 
1615 
1616 // Helper for PhaseMacroExpand::expand_allocate_common.
1617 // Initializes the newly-allocated storage.
1618 Node*
1619 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1620                                     Node* control, Node* rawmem, Node* object,
1621                                     Node* klass_node, Node* length,
1622                                     Node* size_in_bytes) {
1623   InitializeNode* init = alloc->initialization();
1624   // Store the klass & mark bits
1625   Node* mark_node = NULL;
1626   // For now only enable fast locking for non-array types
1627   if (UseBiasedLocking && (length == NULL)) {
1628     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1629   } else {
1630     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1631   }
1632   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1633 
1634   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1635   int header_size = alloc->minimum_header_size();  // conservatively small
1636 
1637   // Array length
1638   if (length != NULL) {         // Arrays need length field
1639     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1640     // conservatively small header size:
1641     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1642     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1643     if (k->is_array_klass())    // we know the exact header size in most cases:
1644       header_size = Klass::layout_helper_header_size(k->layout_helper());
1645   }
1646 
1647   // Clear the object body, if necessary.
1648   if (init == NULL) {
1649     // The init has somehow disappeared; be cautious and clear everything.
1650     //
1651     // This can happen if a node is allocated but an uncommon trap occurs
1652     // immediately.  In this case, the Initialize gets associated with the
1653     // trap, and may be placed in a different (outer) loop, if the Allocate
1654     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
1655     // there can be two Allocates to one Initialize.  The answer in all these
1656     // edge cases is safety first.  It is always safe to clear immediately
1657     // within an Allocate, and then (maybe or maybe not) clear some more later.
1658     if (!ZeroTLAB)
1659       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1660                                             header_size, size_in_bytes,
1661                                             &_igvn);
1662   } else {
1663     if (!init->is_complete()) {
1664       // Try to win by zeroing only what the init does not store.
1665       // We can also try to do some peephole optimizations,
1666       // such as combining some adjacent subword stores.
1667       rawmem = init->complete_stores(control, rawmem, object,
1668                                      header_size, size_in_bytes, &_igvn);
1669     }
1670     // We have no more use for this link, since the AllocateNode goes away:
1671     init->set_req(InitializeNode::RawAddress, top());
1672     // (If we keep the link, it just confuses the register allocator,
1673     // who thinks he sees a real use of the address by the membar.)
1674   }
1675 
1676   return rawmem;
1677 }
1678 
1679 // Generate prefetch instructions for next allocations.
1680 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1681                                         Node*& contended_phi_rawmem,
1682                                         Node* old_eden_top, Node* new_eden_top,
1683                                         Node* length) {
1684    enum { fall_in_path = 1, pf_path = 2 };
1685    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1686       // Generate prefetch allocation with watermark check.
1687       // As an allocation hits the watermark, we will prefetch starting
1688       // at a "distance" away from watermark.
1689 
1690       Node *pf_region = new (C) RegionNode(3);
1691       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
1692                                                 TypeRawPtr::BOTTOM );
1693       // I/O is used for Prefetch
1694       Node *pf_phi_abio = new (C) PhiNode( pf_region, Type::ABIO );
1695 
1696       Node *thread = new (C) ThreadLocalNode();
1697       transform_later(thread);
1698 
1699       Node *eden_pf_adr = new (C) AddPNode( top()/*not oop*/, thread,
1700                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1701       transform_later(eden_pf_adr);
1702 
1703       Node *old_pf_wm = new (C) LoadPNode(needgc_false,
1704                                    contended_phi_rawmem, eden_pf_adr,
1705                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1706                                    LoadNode::unordered);
1707       transform_later(old_pf_wm);
1708 
1709       // check against new_eden_top
1710       Node *need_pf_cmp = new (C) CmpPNode( new_eden_top, old_pf_wm );
1711       transform_later(need_pf_cmp);
1712       Node *need_pf_bol = new (C) BoolNode( need_pf_cmp, BoolTest::ge );
1713       transform_later(need_pf_bol);
1714       IfNode *need_pf_iff = new (C) IfNode( needgc_false, need_pf_bol,
1715                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1716       transform_later(need_pf_iff);
1717 
1718       // true node, add prefetchdistance
1719       Node *need_pf_true = new (C) IfTrueNode( need_pf_iff );
1720       transform_later(need_pf_true);
1721 
1722       Node *need_pf_false = new (C) IfFalseNode( need_pf_iff );
1723       transform_later(need_pf_false);
1724 
1725       Node *new_pf_wmt = new (C) AddPNode( top(), old_pf_wm,
1726                                     _igvn.MakeConX(AllocatePrefetchDistance) );
1727       transform_later(new_pf_wmt );
1728       new_pf_wmt->set_req(0, need_pf_true);
1729 
1730       Node *store_new_wmt = new (C) StorePNode(need_pf_true,
1731                                        contended_phi_rawmem, eden_pf_adr,
1732                                        TypeRawPtr::BOTTOM, new_pf_wmt,
1733                                        StoreNode::unordered);
1734       transform_later(store_new_wmt);
1735 
1736       // adding prefetches
1737       pf_phi_abio->init_req( fall_in_path, i_o );
1738 
1739       Node *prefetch_adr;
1740       Node *prefetch;
1741       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1742       uint step_size = AllocatePrefetchStepSize;
1743       uint distance = 0;
1744 
1745       for ( uint i = 0; i < lines; i++ ) {
1746         prefetch_adr = new (C) AddPNode( old_pf_wm, new_pf_wmt,
1747                                             _igvn.MakeConX(distance) );
1748         transform_later(prefetch_adr);
1749         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
1750         transform_later(prefetch);
1751         distance += step_size;
1752         i_o = prefetch;
1753       }
1754       pf_phi_abio->set_req( pf_path, i_o );
1755 
1756       pf_region->init_req( fall_in_path, need_pf_false );
1757       pf_region->init_req( pf_path, need_pf_true );
1758 
1759       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1760       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1761 
1762       transform_later(pf_region);
1763       transform_later(pf_phi_rawmem);
1764       transform_later(pf_phi_abio);
1765 
1766       needgc_false = pf_region;
1767       contended_phi_rawmem = pf_phi_rawmem;
1768       i_o = pf_phi_abio;
1769    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1770       // Insert a prefetch for each allocation.
1771       // This code is used for Sparc with BIS.
1772       Node *pf_region = new (C) RegionNode(3);
1773       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
1774                                              TypeRawPtr::BOTTOM );
1775 
1776       // Generate several prefetch instructions.
1777       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1778       uint step_size = AllocatePrefetchStepSize;
1779       uint distance = AllocatePrefetchDistance;
1780 
1781       // Next cache address.
1782       Node *cache_adr = new (C) AddPNode(old_eden_top, old_eden_top,
1783                                             _igvn.MakeConX(distance));
1784       transform_later(cache_adr);
1785       cache_adr = new (C) CastP2XNode(needgc_false, cache_adr);
1786       transform_later(cache_adr);
1787       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1788       cache_adr = new (C) AndXNode(cache_adr, mask);
1789       transform_later(cache_adr);
1790       cache_adr = new (C) CastX2PNode(cache_adr);
1791       transform_later(cache_adr);
1792 
1793       // Prefetch
1794       Node *prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1795       prefetch->set_req(0, needgc_false);
1796       transform_later(prefetch);
1797       contended_phi_rawmem = prefetch;
1798       Node *prefetch_adr;
1799       distance = step_size;
1800       for ( uint i = 1; i < lines; i++ ) {
1801         prefetch_adr = new (C) AddPNode( cache_adr, cache_adr,
1802                                             _igvn.MakeConX(distance) );
1803         transform_later(prefetch_adr);
1804         prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1805         transform_later(prefetch);
1806         distance += step_size;
1807         contended_phi_rawmem = prefetch;
1808       }
1809    } else if( AllocatePrefetchStyle > 0 ) {
1810       // Insert a prefetch for each allocation only on the fast-path
1811       Node *prefetch_adr;
1812       Node *prefetch;
1813       // Generate several prefetch instructions.
1814       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1815       uint step_size = AllocatePrefetchStepSize;
1816       uint distance = AllocatePrefetchDistance;
1817       for ( uint i = 0; i < lines; i++ ) {
1818         prefetch_adr = new (C) AddPNode( old_eden_top, new_eden_top,
1819                                             _igvn.MakeConX(distance) );
1820         transform_later(prefetch_adr);
1821         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
1822         // Do not let it float too high, since if eden_top == eden_end,
1823         // both might be null.
1824         if( i == 0 ) { // Set control for first prefetch, next follows it
1825           prefetch->init_req(0, needgc_false);
1826         }
1827         transform_later(prefetch);
1828         distance += step_size;
1829         i_o = prefetch;
1830       }
1831    }
1832    return i_o;
1833 }
1834 
1835 
1836 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1837   expand_allocate_common(alloc, NULL,
1838                          OptoRuntime::new_instance_Type(),
1839                          OptoRuntime::new_instance_Java());
1840 }
1841 
1842 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1843   Node* length = alloc->in(AllocateNode::ALength);
1844   InitializeNode* init = alloc->initialization();
1845   Node* klass_node = alloc->in(AllocateNode::KlassNode);
1846   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1847   address slow_call_address;  // Address of slow call
1848   if (init != NULL && init->is_complete_with_arraycopy() &&
1849       k->is_type_array_klass()) {
1850     // Don't zero type array during slow allocation in VM since
1851     // it will be initialized later by arraycopy in compiled code.
1852     slow_call_address = OptoRuntime::new_array_nozero_Java();
1853   } else {
1854     slow_call_address = OptoRuntime::new_array_Java();
1855   }
1856   expand_allocate_common(alloc, length,
1857                          OptoRuntime::new_array_Type(),
1858                          slow_call_address);
1859 }
1860 
1861 //-------------------mark_eliminated_box----------------------------------
1862 //
1863 // During EA obj may point to several objects but after few ideal graph
1864 // transformations (CCP) it may point to only one non escaping object
1865 // (but still using phi), corresponding locks and unlocks will be marked
1866 // for elimination. Later obj could be replaced with a new node (new phi)
1867 // and which does not have escape information. And later after some graph
1868 // reshape other locks and unlocks (which were not marked for elimination
1869 // before) are connected to this new obj (phi) but they still will not be
1870 // marked for elimination since new obj has no escape information.
1871 // Mark all associated (same box and obj) lock and unlock nodes for
1872 // elimination if some of them marked already.
1873 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1874   if (oldbox->as_BoxLock()->is_eliminated())
1875     return; // This BoxLock node was processed already.
1876 
1877   // New implementation (EliminateNestedLocks) has separate BoxLock
1878   // node for each locked region so mark all associated locks/unlocks as
1879   // eliminated even if different objects are referenced in one locked region
1880   // (for example, OSR compilation of nested loop inside locked scope).
1881   if (EliminateNestedLocks ||
1882       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
1883     // Box is used only in one lock region. Mark this box as eliminated.
1884     _igvn.hash_delete(oldbox);
1885     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1886     _igvn.hash_insert(oldbox);
1887 
1888     for (uint i = 0; i < oldbox->outcnt(); i++) {
1889       Node* u = oldbox->raw_out(i);
1890       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1891         AbstractLockNode* alock = u->as_AbstractLock();
1892         // Check lock's box since box could be referenced by Lock's debug info.
1893         if (alock->box_node() == oldbox) {
1894           // Mark eliminated all related locks and unlocks.
1895           alock->set_non_esc_obj();
1896         }
1897       }
1898     }
1899     return;
1900   }
1901 
1902   // Create new "eliminated" BoxLock node and use it in monitor debug info
1903   // instead of oldbox for the same object.
1904   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1905 
1906   // Note: BoxLock node is marked eliminated only here and it is used
1907   // to indicate that all associated lock and unlock nodes are marked
1908   // for elimination.
1909   newbox->set_eliminated();
1910   transform_later(newbox);
1911 
1912   // Replace old box node with new box for all users of the same object.
1913   for (uint i = 0; i < oldbox->outcnt();) {
1914     bool next_edge = true;
1915 
1916     Node* u = oldbox->raw_out(i);
1917     if (u->is_AbstractLock()) {
1918       AbstractLockNode* alock = u->as_AbstractLock();
1919       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
1920         // Replace Box and mark eliminated all related locks and unlocks.
1921         alock->set_non_esc_obj();
1922         _igvn.rehash_node_delayed(alock);
1923         alock->set_box_node(newbox);
1924         next_edge = false;
1925       }
1926     }
1927     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
1928       FastLockNode* flock = u->as_FastLock();
1929       assert(flock->box_node() == oldbox, "sanity");
1930       _igvn.rehash_node_delayed(flock);
1931       flock->set_box_node(newbox);
1932       next_edge = false;
1933     }
1934 
1935     // Replace old box in monitor debug info.
1936     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1937       SafePointNode* sfn = u->as_SafePoint();
1938       JVMState* youngest_jvms = sfn->jvms();
1939       int max_depth = youngest_jvms->depth();
1940       for (int depth = 1; depth <= max_depth; depth++) {
1941         JVMState* jvms = youngest_jvms->of_depth(depth);
1942         int num_mon  = jvms->nof_monitors();
1943         // Loop over monitors
1944         for (int idx = 0; idx < num_mon; idx++) {
1945           Node* obj_node = sfn->monitor_obj(jvms, idx);
1946           Node* box_node = sfn->monitor_box(jvms, idx);
1947           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
1948             int j = jvms->monitor_box_offset(idx);
1949             _igvn.replace_input_of(u, j, newbox);
1950             next_edge = false;
1951           }
1952         }
1953       }
1954     }
1955     if (next_edge) i++;
1956   }
1957 }
1958 
1959 //-----------------------mark_eliminated_locking_nodes-----------------------
1960 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1961   if (EliminateNestedLocks) {
1962     if (alock->is_nested()) {
1963        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
1964        return;
1965     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
1966       // Only Lock node has JVMState needed here.
1967       if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
1968         // Mark eliminated related nested locks and unlocks.
1969         Node* obj = alock->obj_node();
1970         BoxLockNode* box_node = alock->box_node()->as_BoxLock();
1971         assert(!box_node->is_eliminated(), "should not be marked yet");
1972         // Note: BoxLock node is marked eliminated only here
1973         // and it is used to indicate that all associated lock
1974         // and unlock nodes are marked for elimination.
1975         box_node->set_eliminated(); // Box's hash is always NO_HASH here
1976         for (uint i = 0; i < box_node->outcnt(); i++) {
1977           Node* u = box_node->raw_out(i);
1978           if (u->is_AbstractLock()) {
1979             alock = u->as_AbstractLock();
1980             if (alock->box_node() == box_node) {
1981               // Verify that this Box is referenced only by related locks.
1982               assert(alock->obj_node()->eqv_uncast(obj), "");
1983               // Mark all related locks and unlocks.
1984               alock->set_nested();
1985             }
1986           }
1987         }
1988       }
1989       return;
1990     }
1991     // Process locks for non escaping object
1992     assert(alock->is_non_esc_obj(), "");
1993   } // EliminateNestedLocks
1994 
1995   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
1996     // Look for all locks of this object and mark them and
1997     // corresponding BoxLock nodes as eliminated.
1998     Node* obj = alock->obj_node();
1999     for (uint j = 0; j < obj->outcnt(); j++) {
2000       Node* o = obj->raw_out(j);
2001       if (o->is_AbstractLock() &&
2002           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2003         alock = o->as_AbstractLock();
2004         Node* box = alock->box_node();
2005         // Replace old box node with new eliminated box for all users
2006         // of the same object and mark related locks as eliminated.
2007         mark_eliminated_box(box, obj);
2008       }
2009     }
2010   }
2011 }
2012 
2013 // we have determined that this lock/unlock can be eliminated, we simply
2014 // eliminate the node without expanding it.
2015 //
2016 // Note:  The membar's associated with the lock/unlock are currently not
2017 //        eliminated.  This should be investigated as a future enhancement.
2018 //
2019 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2020 
2021   if (!alock->is_eliminated()) {
2022     return false;
2023   }
2024 #ifdef ASSERT
2025   if (!alock->is_coarsened()) {
2026     // Check that new "eliminated" BoxLock node is created.
2027     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2028     assert(oldbox->is_eliminated(), "should be done already");
2029   }
2030 #endif
2031   CompileLog* log = C->log();
2032   if (log != NULL) {
2033     log->head("eliminate_lock lock='%d'",
2034               alock->is_Lock());
2035     JVMState* p = alock->jvms();
2036     while (p != NULL) {
2037       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
2038       p = p->caller();
2039     }
2040     log->tail("eliminate_lock");
2041   }
2042 
2043   #ifndef PRODUCT
2044   if (PrintEliminateLocks) {
2045     if (alock->is_Lock()) {
2046       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2047     } else {
2048       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2049     }
2050   }
2051   #endif
2052 
2053   Node* mem  = alock->in(TypeFunc::Memory);
2054   Node* ctrl = alock->in(TypeFunc::Control);
2055 
2056   extract_call_projections(alock);
2057   // There are 2 projections from the lock.  The lock node will
2058   // be deleted when its last use is subsumed below.
2059   assert(alock->outcnt() == 2 &&
2060          _fallthroughproj != NULL &&
2061          _memproj_fallthrough != NULL,
2062          "Unexpected projections from Lock/Unlock");
2063 
2064   Node* fallthroughproj = _fallthroughproj;
2065   Node* memproj_fallthrough = _memproj_fallthrough;
2066 
2067   // The memory projection from a lock/unlock is RawMem
2068   // The input to a Lock is merged memory, so extract its RawMem input
2069   // (unless the MergeMem has been optimized away.)
2070   if (alock->is_Lock()) {
2071     // Seach for MemBarAcquireLock node and delete it also.
2072     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2073     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2074     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2075     Node* memproj = membar->proj_out(TypeFunc::Memory);
2076     _igvn.replace_node(ctrlproj, fallthroughproj);
2077     _igvn.replace_node(memproj, memproj_fallthrough);
2078 
2079     // Delete FastLock node also if this Lock node is unique user
2080     // (a loop peeling may clone a Lock node).
2081     Node* flock = alock->as_Lock()->fastlock_node();
2082     if (flock->outcnt() == 1) {
2083       assert(flock->unique_out() == alock, "sanity");
2084       _igvn.replace_node(flock, top());
2085     }
2086   }
2087 
2088   // Seach for MemBarReleaseLock node and delete it also.
2089   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
2090       ctrl->in(0)->is_MemBar()) {
2091     MemBarNode* membar = ctrl->in(0)->as_MemBar();
2092     assert(membar->Opcode() == Op_MemBarReleaseLock &&
2093            mem->is_Proj() && membar == mem->in(0), "");
2094     _igvn.replace_node(fallthroughproj, ctrl);
2095     _igvn.replace_node(memproj_fallthrough, mem);
2096     fallthroughproj = ctrl;
2097     memproj_fallthrough = mem;
2098     ctrl = membar->in(TypeFunc::Control);
2099     mem  = membar->in(TypeFunc::Memory);
2100   }
2101 
2102   _igvn.replace_node(fallthroughproj, ctrl);
2103   _igvn.replace_node(memproj_fallthrough, mem);
2104   return true;
2105 }
2106 
2107 
2108 //------------------------------expand_lock_node----------------------
2109 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2110 
2111   Node* ctrl = lock->in(TypeFunc::Control);
2112   Node* mem = lock->in(TypeFunc::Memory);
2113   Node* obj = lock->obj_node();
2114   Node* box = lock->box_node();
2115   Node* flock = lock->fastlock_node();
2116 
2117   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2118 
2119   // Make the merge point
2120   Node *region;
2121   Node *mem_phi;
2122   Node *slow_path;
2123 
2124   if (UseOptoBiasInlining) {
2125     /*
2126      *  See the full description in MacroAssembler::biased_locking_enter().
2127      *
2128      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2129      *    // The object is biased.
2130      *    proto_node = klass->prototype_header;
2131      *    o_node = thread | proto_node;
2132      *    x_node = o_node ^ mark_word;
2133      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2134      *      // Done.
2135      *    } else {
2136      *      if( (x_node & biased_lock_mask) != 0 ) {
2137      *        // The klass's prototype header is no longer biased.
2138      *        cas(&mark_word, mark_word, proto_node)
2139      *        goto cas_lock;
2140      *      } else {
2141      *        // The klass's prototype header is still biased.
2142      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2143      *          old = mark_word;
2144      *          new = o_node;
2145      *        } else {
2146      *          // Different thread or anonymous biased.
2147      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2148      *          new = thread | old;
2149      *        }
2150      *        // Try to rebias.
2151      *        if( cas(&mark_word, old, new) == 0 ) {
2152      *          // Done.
2153      *        } else {
2154      *          goto slow_path; // Failed.
2155      *        }
2156      *      }
2157      *    }
2158      *  } else {
2159      *    // The object is not biased.
2160      *    cas_lock:
2161      *    if( FastLock(obj) == 0 ) {
2162      *      // Done.
2163      *    } else {
2164      *      slow_path:
2165      *      OptoRuntime::complete_monitor_locking_Java(obj);
2166      *    }
2167      *  }
2168      */
2169 
2170     region  = new (C) RegionNode(5);
2171     // create a Phi for the memory state
2172     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2173 
2174     Node* fast_lock_region  = new (C) RegionNode(3);
2175     Node* fast_lock_mem_phi = new (C) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2176 
2177     // First, check mark word for the biased lock pattern.
2178     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2179 
2180     // Get fast path - mark word has the biased lock pattern.
2181     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2182                          markOopDesc::biased_lock_mask_in_place,
2183                          markOopDesc::biased_lock_pattern, true);
2184     // fast_lock_region->in(1) is set to slow path.
2185     fast_lock_mem_phi->init_req(1, mem);
2186 
2187     // Now check that the lock is biased to the current thread and has
2188     // the same epoch and bias as Klass::_prototype_header.
2189 
2190     // Special-case a fresh allocation to avoid building nodes:
2191     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2192     if (klass_node == NULL) {
2193       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2194       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
2195 #ifdef _LP64
2196       if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2197         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2198         klass_node->in(1)->init_req(0, ctrl);
2199       } else
2200 #endif
2201       klass_node->init_req(0, ctrl);
2202     }
2203     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2204 
2205     Node* thread = transform_later(new (C) ThreadLocalNode());
2206     Node* cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
2207     Node* o_node = transform_later(new (C) OrXNode(cast_thread, proto_node));
2208     Node* x_node = transform_later(new (C) XorXNode(o_node, mark_node));
2209 
2210     // Get slow path - mark word does NOT match the value.
2211     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
2212                                       (~markOopDesc::age_mask_in_place), 0);
2213     // region->in(3) is set to fast path - the object is biased to the current thread.
2214     mem_phi->init_req(3, mem);
2215 
2216 
2217     // Mark word does NOT match the value (thread | Klass::_prototype_header).
2218 
2219 
2220     // First, check biased pattern.
2221     // Get fast path - _prototype_header has the same biased lock pattern.
2222     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2223                           markOopDesc::biased_lock_mask_in_place, 0, true);
2224 
2225     not_biased_ctrl = fast_lock_region->in(2); // Slow path
2226     // fast_lock_region->in(2) - the prototype header is no longer biased
2227     // and we have to revoke the bias on this object.
2228     // We are going to try to reset the mark of this object to the prototype
2229     // value and fall through to the CAS-based locking scheme.
2230     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2231     Node* cas = new (C) StoreXConditionalNode(not_biased_ctrl, mem, adr,
2232                                               proto_node, mark_node);
2233     transform_later(cas);
2234     Node* proj = transform_later( new (C) SCMemProjNode(cas));
2235     fast_lock_mem_phi->init_req(2, proj);
2236 
2237 
2238     // Second, check epoch bits.
2239     Node* rebiased_region  = new (C) RegionNode(3);
2240     Node* old_phi = new (C) PhiNode( rebiased_region, TypeX_X);
2241     Node* new_phi = new (C) PhiNode( rebiased_region, TypeX_X);
2242 
2243     // Get slow path - mark word does NOT match epoch bits.
2244     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
2245                                       markOopDesc::epoch_mask_in_place, 0);
2246     // The epoch of the current bias is not valid, attempt to rebias the object
2247     // toward the current thread.
2248     rebiased_region->init_req(2, epoch_ctrl);
2249     old_phi->init_req(2, mark_node);
2250     new_phi->init_req(2, o_node);
2251 
2252     // rebiased_region->in(1) is set to fast path.
2253     // The epoch of the current bias is still valid but we know
2254     // nothing about the owner; it might be set or it might be clear.
2255     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
2256                              markOopDesc::age_mask_in_place |
2257                              markOopDesc::epoch_mask_in_place);
2258     Node* old = transform_later(new (C) AndXNode(mark_node, cmask));
2259     cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
2260     Node* new_mark = transform_later(new (C) OrXNode(cast_thread, old));
2261     old_phi->init_req(1, old);
2262     new_phi->init_req(1, new_mark);
2263 
2264     transform_later(rebiased_region);
2265     transform_later(old_phi);
2266     transform_later(new_phi);
2267 
2268     // Try to acquire the bias of the object using an atomic operation.
2269     // If this fails we will go in to the runtime to revoke the object's bias.
2270     cas = new (C) StoreXConditionalNode(rebiased_region, mem, adr,
2271                                            new_phi, old_phi);
2272     transform_later(cas);
2273     proj = transform_later( new (C) SCMemProjNode(cas));
2274 
2275     // Get slow path - Failed to CAS.
2276     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2277     mem_phi->init_req(4, proj);
2278     // region->in(4) is set to fast path - the object is rebiased to the current thread.
2279 
2280     // Failed to CAS.
2281     slow_path  = new (C) RegionNode(3);
2282     Node *slow_mem = new (C) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2283 
2284     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2285     slow_mem->init_req(1, proj);
2286 
2287     // Call CAS-based locking scheme (FastLock node).
2288 
2289     transform_later(fast_lock_region);
2290     transform_later(fast_lock_mem_phi);
2291 
2292     // Get slow path - FastLock failed to lock the object.
2293     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2294     mem_phi->init_req(2, fast_lock_mem_phi);
2295     // region->in(2) is set to fast path - the object is locked to the current thread.
2296 
2297     slow_path->init_req(2, ctrl); // Capture slow-control
2298     slow_mem->init_req(2, fast_lock_mem_phi);
2299 
2300     transform_later(slow_path);
2301     transform_later(slow_mem);
2302     // Reset lock's memory edge.
2303     lock->set_req(TypeFunc::Memory, slow_mem);
2304 
2305   } else {
2306     region  = new (C) RegionNode(3);
2307     // create a Phi for the memory state
2308     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2309 
2310     // Optimize test; set region slot 2
2311     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2312     mem_phi->init_req(2, mem);
2313   }
2314 
2315   // Make slow path call
2316   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2317 
2318   extract_call_projections(call);
2319 
2320   // Slow path can only throw asynchronous exceptions, which are always
2321   // de-opted.  So the compiler thinks the slow-call can never throw an
2322   // exception.  If it DOES throw an exception we would need the debug
2323   // info removed first (since if it throws there is no monitor).
2324   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2325            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2326 
2327   // Capture slow path
2328   // disconnect fall-through projection from call and create a new one
2329   // hook up users of fall-through projection to region
2330   Node *slow_ctrl = _fallthroughproj->clone();
2331   transform_later(slow_ctrl);
2332   _igvn.hash_delete(_fallthroughproj);
2333   _fallthroughproj->disconnect_inputs(NULL, C);
2334   region->init_req(1, slow_ctrl);
2335   // region inputs are now complete
2336   transform_later(region);
2337   _igvn.replace_node(_fallthroughproj, region);
2338 
2339   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
2340   mem_phi->init_req(1, memproj );
2341   transform_later(mem_phi);
2342   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2343 }
2344 
2345 //------------------------------expand_unlock_node----------------------
2346 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2347 
2348   Node* ctrl = unlock->in(TypeFunc::Control);
2349   Node* mem = unlock->in(TypeFunc::Memory);
2350   Node* obj = unlock->obj_node();
2351   Node* box = unlock->box_node();
2352 
2353   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2354 
2355   // No need for a null check on unlock
2356 
2357   // Make the merge point
2358   Node *region;
2359   Node *mem_phi;
2360 
2361   if (UseOptoBiasInlining) {
2362     // Check for biased locking unlock case, which is a no-op.
2363     // See the full description in MacroAssembler::biased_locking_exit().
2364     region  = new (C) RegionNode(4);
2365     // create a Phi for the memory state
2366     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2367     mem_phi->init_req(3, mem);
2368 
2369     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2370     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2371                          markOopDesc::biased_lock_mask_in_place,
2372                          markOopDesc::biased_lock_pattern);
2373   } else {
2374     region  = new (C) RegionNode(3);
2375     // create a Phi for the memory state
2376     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2377   }
2378 
2379   FastUnlockNode *funlock = new (C) FastUnlockNode( ctrl, obj, box );
2380   funlock = transform_later( funlock )->as_FastUnlock();
2381   // Optimize test; set region slot 2
2382   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2383 
2384   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 );
2385 
2386   extract_call_projections(call);
2387 
2388   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2389            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2390 
2391   // No exceptions for unlocking
2392   // Capture slow path
2393   // disconnect fall-through projection from call and create a new one
2394   // hook up users of fall-through projection to region
2395   Node *slow_ctrl = _fallthroughproj->clone();
2396   transform_later(slow_ctrl);
2397   _igvn.hash_delete(_fallthroughproj);
2398   _fallthroughproj->disconnect_inputs(NULL, C);
2399   region->init_req(1, slow_ctrl);
2400   // region inputs are now complete
2401   transform_later(region);
2402   _igvn.replace_node(_fallthroughproj, region);
2403 
2404   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
2405   mem_phi->init_req(1, memproj );
2406   mem_phi->init_req(2, mem);
2407   transform_later(mem_phi);
2408   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2409 }
2410 
2411 //---------------------------eliminate_macro_nodes----------------------
2412 // Eliminate scalar replaced allocations and associated locks.
2413 void PhaseMacroExpand::eliminate_macro_nodes() {
2414   if (C->macro_count() == 0)
2415     return;
2416 
2417   // First, attempt to eliminate locks
2418   int cnt = C->macro_count();
2419   for (int i=0; i < cnt; i++) {
2420     Node *n = C->macro_node(i);
2421     if (n->is_AbstractLock()) { // Lock and Unlock nodes
2422       // Before elimination mark all associated (same box and obj)
2423       // lock and unlock nodes.
2424       mark_eliminated_locking_nodes(n->as_AbstractLock());
2425     }
2426   }
2427   bool progress = true;
2428   while (progress) {
2429     progress = false;
2430     for (int i = C->macro_count(); i > 0; i--) {
2431       Node * n = C->macro_node(i-1);
2432       bool success = false;
2433       debug_only(int old_macro_count = C->macro_count(););
2434       if (n->is_AbstractLock()) {
2435         success = eliminate_locking_node(n->as_AbstractLock());
2436       }
2437       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2438       progress = progress || success;
2439     }
2440   }
2441   // Next, attempt to eliminate allocations
2442   progress = true;
2443   while (progress) {
2444     progress = false;
2445     for (int i = C->macro_count(); i > 0; i--) {
2446       Node * n = C->macro_node(i-1);
2447       bool success = false;
2448       debug_only(int old_macro_count = C->macro_count(););
2449       switch (n->class_id()) {
2450       case Node::Class_Allocate:
2451       case Node::Class_AllocateArray:
2452         success = eliminate_allocate_node(n->as_Allocate());
2453         break;
2454       case Node::Class_CallStaticJava:
2455         success = eliminate_boxing_node(n->as_CallStaticJava());
2456         break;
2457       case Node::Class_Lock:
2458       case Node::Class_Unlock:
2459         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2460         break;
2461       default:
2462         assert(n->Opcode() == Op_LoopLimit ||
2463                n->Opcode() == Op_Opaque1   ||
2464                n->Opcode() == Op_Opaque2, "unknown node type in macro list");
2465       }
2466       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2467       progress = progress || success;
2468     }
2469   }
2470 }
2471 
2472 //------------------------------expand_macro_nodes----------------------
2473 //  Returns true if a failure occurred.
2474 bool PhaseMacroExpand::expand_macro_nodes() {
2475   // Last attempt to eliminate macro nodes.
2476   eliminate_macro_nodes();
2477 
2478   // Make sure expansion will not cause node limit to be exceeded.
2479   // Worst case is a macro node gets expanded into about 50 nodes.
2480   // Allow 50% more for optimization.
2481   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2482     return true;
2483 
2484   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2485   bool progress = true;
2486   while (progress) {
2487     progress = false;
2488     for (int i = C->macro_count(); i > 0; i--) {
2489       Node * n = C->macro_node(i-1);
2490       bool success = false;
2491       debug_only(int old_macro_count = C->macro_count(););
2492       if (n->Opcode() == Op_LoopLimit) {
2493         // Remove it from macro list and put on IGVN worklist to optimize.
2494         C->remove_macro_node(n);
2495         _igvn._worklist.push(n);
2496         success = true;
2497       } else if (n->Opcode() == Op_CallStaticJava) {
2498         // Remove it from macro list and put on IGVN worklist to optimize.
2499         C->remove_macro_node(n);
2500         _igvn._worklist.push(n);
2501         success = true;
2502       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2503         _igvn.replace_node(n, n->in(1));
2504         success = true;
2505       }
2506       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2507       progress = progress || success;
2508     }
2509   }
2510 
2511   // expand "macro" nodes
2512   // nodes are removed from the macro list as they are processed
2513   while (C->macro_count() > 0) {
2514     int macro_count = C->macro_count();
2515     Node * n = C->macro_node(macro_count-1);
2516     assert(n->is_macro(), "only macro nodes expected here");
2517     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2518       // node is unreachable, so don't try to expand it
2519       C->remove_macro_node(n);
2520       continue;
2521     }
2522     switch (n->class_id()) {
2523     case Node::Class_Allocate:
2524       expand_allocate(n->as_Allocate());
2525       break;
2526     case Node::Class_AllocateArray:
2527       expand_allocate_array(n->as_AllocateArray());
2528       break;
2529     case Node::Class_Lock:
2530       expand_lock_node(n->as_Lock());
2531       break;
2532     case Node::Class_Unlock:
2533       expand_unlock_node(n->as_Unlock());
2534       break;
2535     default:
2536       assert(false, "unknown node type in macro list");
2537     }
2538     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2539     if (C->failing())  return true;
2540   }
2541 
2542   _igvn.set_delay_transform(false);
2543   _igvn.optimize();
2544   if (C->failing())  return true;
2545   return false;
2546 }