1 /*
   2  * Copyright (c) 2005, 2015, 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/castnode.hpp"
  31 #include "opto/cfgnode.hpp"
  32 #include "opto/compile.hpp"
  33 #include "opto/convertnode.hpp"
  34 #include "opto/locknode.hpp"
  35 #include "opto/loopnode.hpp"
  36 #include "opto/macro.hpp"
  37 #include "opto/memnode.hpp"
  38 #include "opto/narrowptrnode.hpp"
  39 #include "opto/node.hpp"
  40 #include "opto/opaquenode.hpp"
  41 #include "opto/phaseX.hpp"
  42 #include "opto/rootnode.hpp"
  43 #include "opto/runtime.hpp"
  44 #include "opto/subnode.hpp"
  45 #include "opto/type.hpp"
  46 #include "runtime/sharedRuntime.hpp"
  47 
  48 
  49 //
  50 // Replace any references to "oldref" in inputs to "use" with "newref".
  51 // Returns the number of replacements made.
  52 //
  53 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
  54   int nreplacements = 0;
  55   uint req = use->req();
  56   for (uint j = 0; j < use->len(); j++) {
  57     Node *uin = use->in(j);
  58     if (uin == oldref) {
  59       if (j < req)
  60         use->set_req(j, newref);
  61       else
  62         use->set_prec(j, newref);
  63       nreplacements++;
  64     } else if (j >= req && uin == NULL) {
  65       break;
  66     }
  67   }
  68   return nreplacements;
  69 }
  70 
  71 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
  72   // Copy debug information and adjust JVMState information
  73   uint old_dbg_start = oldcall->tf()->domain()->cnt();
  74   uint new_dbg_start = newcall->tf()->domain()->cnt();
  75   int jvms_adj  = new_dbg_start - old_dbg_start;
  76   assert (new_dbg_start == newcall->req(), "argument count mismatch");
  77 
  78   // SafePointScalarObject node could be referenced several times in debug info.
  79   // Use Dict to record cloned nodes.
  80   Dict* sosn_map = new Dict(cmpkey,hashkey);
  81   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
  82     Node* old_in = oldcall->in(i);
  83     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
  84     if (old_in != NULL && old_in->is_SafePointScalarObject()) {
  85       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
  86       uint old_unique = C->unique();
  87       Node* new_in = old_sosn->clone(sosn_map);
  88       if (old_unique != C->unique()) { // New node?
  89         new_in->set_req(0, C->root()); // reset control edge
  90         new_in = transform_later(new_in); // Register new node.
  91       }
  92       old_in = new_in;
  93     }
  94     newcall->add_req(old_in);
  95   }
  96 
  97   // JVMS may be shared so clone it before we modify it
  98   newcall->set_jvms(oldcall->jvms() != NULL ? oldcall->jvms()->clone_deep(C) : NULL);
  99   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
 100     jvms->set_map(newcall);
 101     jvms->set_locoff(jvms->locoff()+jvms_adj);
 102     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
 103     jvms->set_monoff(jvms->monoff()+jvms_adj);
 104     jvms->set_scloff(jvms->scloff()+jvms_adj);
 105     jvms->set_endoff(jvms->endoff()+jvms_adj);
 106   }
 107 }
 108 
 109 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
 110   Node* cmp;
 111   if (mask != 0) {
 112     Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
 113     cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
 114   } else {
 115     cmp = word;
 116   }
 117   Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
 118   IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
 119   transform_later(iff);
 120 
 121   // Fast path taken.
 122   Node *fast_taken = transform_later(new IfFalseNode(iff));
 123 
 124   // Fast path not-taken, i.e. slow path
 125   Node *slow_taken = transform_later(new IfTrueNode(iff));
 126 
 127   if (return_fast_path) {
 128     region->init_req(edge, slow_taken); // Capture slow-control
 129     return fast_taken;
 130   } else {
 131     region->init_req(edge, fast_taken); // Capture fast-control
 132     return slow_taken;
 133   }
 134 }
 135 
 136 //--------------------copy_predefined_input_for_runtime_call--------------------
 137 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
 138   // Set fixed predefined input arguments
 139   call->init_req( TypeFunc::Control, ctrl );
 140   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
 141   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
 142   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
 143   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
 144 }
 145 
 146 //------------------------------make_slow_call---------------------------------
 147 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) {
 148 
 149   // Slow-path call
 150  CallNode *call = leaf_name
 151    ? (CallNode*)new CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
 152    : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
 153 
 154   // Slow path call has no side-effects, uses few values
 155   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
 156   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
 157   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
 158   copy_call_debug_info(oldcall, call);
 159   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
 160   _igvn.replace_node(oldcall, call);
 161   transform_later(call);
 162 
 163   return call;
 164 }
 165 
 166 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
 167   _fallthroughproj = NULL;
 168   _fallthroughcatchproj = NULL;
 169   _ioproj_fallthrough = NULL;
 170   _ioproj_catchall = NULL;
 171   _catchallcatchproj = NULL;
 172   _memproj_fallthrough = NULL;
 173   _memproj_catchall = NULL;
 174   _resproj = NULL;
 175   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
 176     ProjNode *pn = call->fast_out(i)->as_Proj();
 177     switch (pn->_con) {
 178       case TypeFunc::Control:
 179       {
 180         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 181         _fallthroughproj = pn;
 182         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 183         const Node *cn = pn->fast_out(j);
 184         if (cn->is_Catch()) {
 185           ProjNode *cpn = NULL;
 186           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 187             cpn = cn->fast_out(k)->as_Proj();
 188             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 189             if (cpn->_con == CatchProjNode::fall_through_index)
 190               _fallthroughcatchproj = cpn;
 191             else {
 192               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 193               _catchallcatchproj = cpn;
 194             }
 195           }
 196         }
 197         break;
 198       }
 199       case TypeFunc::I_O:
 200         if (pn->_is_io_use)
 201           _ioproj_catchall = pn;
 202         else
 203           _ioproj_fallthrough = pn;
 204         break;
 205       case TypeFunc::Memory:
 206         if (pn->_is_io_use)
 207           _memproj_catchall = pn;
 208         else
 209           _memproj_fallthrough = pn;
 210         break;
 211       case TypeFunc::Parms:
 212         _resproj = pn;
 213         break;
 214       default:
 215         assert(false, "unexpected projection from allocation node.");
 216     }
 217   }
 218 
 219 }
 220 
 221 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
 222 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
 223   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
 224   if (!UseG1GC) {
 225     // vanilla/CMS post barrier
 226     Node *shift = p2x->unique_out();
 227     Node *addp = shift->unique_out();
 228     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 229       Node *mem = addp->last_out(j);
 230       if (UseCondCardMark && mem->is_Load()) {
 231         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 232         // The load is checking if the card has been written so
 233         // replace it with zero to fold the test.
 234         _igvn.replace_node(mem, intcon(0));
 235         continue;
 236       }
 237       assert(mem->is_Store(), "store required");
 238       _igvn.replace_node(mem, mem->in(MemNode::Memory));
 239     }
 240   } else {
 241     // G1 pre/post barriers
 242     assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
 243     // It could be only one user, URShift node, in Object.clone() instrinsic
 244     // but the new allocation is passed to arraycopy stub and it could not
 245     // be scalar replaced. So we don't check the case.
 246 
 247     // An other case of only one user (Xor) is when the value check for NULL
 248     // in G1 post barrier is folded after CCP so the code which used URShift
 249     // is removed.
 250 
 251     // Take Region node before eliminating post barrier since it also
 252     // eliminates CastP2X node when it has only one user.
 253     Node* this_region = p2x->in(0);
 254     assert(this_region != NULL, "");
 255 
 256     // Remove G1 post barrier.
 257 
 258     // Search for CastP2X->Xor->URShift->Cmp path which
 259     // checks if the store done to a different from the value's region.
 260     // And replace Cmp with #0 (false) to collapse G1 post barrier.
 261     Node* xorx = p2x->find_out_with(Op_XorX);
 262     assert(xorx != NULL, "missing G1 post barrier");
 263     Node* shift = xorx->unique_out();
 264     Node* cmpx = shift->unique_out();
 265     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
 266     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
 267     "missing region check in G1 post barrier");
 268     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 269 
 270     // Remove G1 pre barrier.
 271 
 272     // Search "if (marking != 0)" check and set it to "false".
 273     // There is no G1 pre barrier if previous stored value is NULL
 274     // (for example, after initialization).
 275     if (this_region->is_Region() && this_region->req() == 3) {
 276       int ind = 1;
 277       if (!this_region->in(ind)->is_IfFalse()) {
 278         ind = 2;
 279       }
 280       if (this_region->in(ind)->is_IfFalse()) {
 281         Node* bol = this_region->in(ind)->in(0)->in(1);
 282         assert(bol->is_Bool(), "");
 283         cmpx = bol->in(1);
 284         if (bol->as_Bool()->_test._test == BoolTest::ne &&
 285             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
 286             cmpx->in(1)->is_Load()) {
 287           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
 288           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
 289                                               PtrQueue::byte_offset_of_active());
 290           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
 291               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
 292               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
 293             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 294           }
 295         }
 296       }
 297     }
 298     // Now CastP2X can be removed since it is used only on dead path
 299     // which currently still alive until igvn optimize it.
 300     assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
 301     _igvn.replace_node(p2x, top());
 302   }
 303 }
 304 
 305 // Search for a memory operation for the specified memory slice.
 306 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
 307   Node *orig_mem = mem;
 308   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 309   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
 310   while (true) {
 311     if (mem == alloc_mem || mem == start_mem ) {
 312       return mem;  // hit one of our sentinels
 313     } else if (mem->is_MergeMem()) {
 314       mem = mem->as_MergeMem()->memory_at(alias_idx);
 315     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 316       Node *in = mem->in(0);
 317       // we can safely skip over safepoints, calls, locks and membars because we
 318       // already know that the object is safe to eliminate.
 319       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 320         return in;
 321       } else if (in->is_Call()) {
 322         CallNode *call = in->as_Call();
 323         if (!call->may_modify(tinst, phase)) {
 324           mem = call->in(TypeFunc::Memory);
 325         }
 326         mem = in->in(TypeFunc::Memory);
 327       } else if (in->is_MemBar()) {
 328         mem = in->in(TypeFunc::Memory);
 329       } else {
 330         assert(false, "unexpected projection");
 331       }
 332     } else if (mem->is_Store()) {
 333       const TypePtr* atype = mem->as_Store()->adr_type();
 334       int adr_idx = Compile::current()->get_alias_index(atype);
 335       if (adr_idx == alias_idx) {
 336         assert(atype->isa_oopptr(), "address type must be oopptr");
 337         int adr_offset = atype->offset();
 338         uint adr_iid = atype->is_oopptr()->instance_id();
 339         // Array elements references have the same alias_idx
 340         // but different offset and different instance_id.
 341         if (adr_offset == offset && adr_iid == alloc->_idx)
 342           return mem;
 343       } else {
 344         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 345       }
 346       mem = mem->in(MemNode::Memory);
 347     } else if (mem->is_ClearArray()) {
 348       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
 349         // Can not bypass initialization of the instance
 350         // we are looking.
 351         debug_only(intptr_t offset;)
 352         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
 353         InitializeNode* init = alloc->as_Allocate()->initialization();
 354         // We are looking for stored value, return Initialize node
 355         // or memory edge from Allocate node.
 356         if (init != NULL)
 357           return init;
 358         else
 359           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
 360       }
 361       // Otherwise skip it (the call updated 'mem' value).
 362     } else if (mem->Opcode() == Op_SCMemProj) {
 363       mem = mem->in(0);
 364       Node* adr = NULL;
 365       if (mem->is_LoadStore()) {
 366         adr = mem->in(MemNode::Address);
 367       } else {
 368         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
 369         adr = mem->in(3); // Destination array
 370       }
 371       const TypePtr* atype = adr->bottom_type()->is_ptr();
 372       int adr_idx = Compile::current()->get_alias_index(atype);
 373       if (adr_idx == alias_idx) {
 374         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 375         return NULL;
 376       }
 377       mem = mem->in(MemNode::Memory);
 378     } else {
 379       return mem;
 380     }
 381     assert(mem != orig_mem, "dead memory loop");
 382   }
 383 }
 384 
 385 //
 386 // Given a Memory Phi, compute a value Phi containing the values from stores
 387 // on the input paths.
 388 // Note: this function is recursive, its depth is limied by the "level" argument
 389 // Returns the computed Phi, or NULL if it cannot compute it.
 390 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) {
 391   assert(mem->is_Phi(), "sanity");
 392   int alias_idx = C->get_alias_index(adr_t);
 393   int offset = adr_t->offset();
 394   int instance_id = adr_t->instance_id();
 395 
 396   // Check if an appropriate value phi already exists.
 397   Node* region = mem->in(0);
 398   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 399     Node* phi = region->fast_out(k);
 400     if (phi->is_Phi() && phi != mem &&
 401         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
 402       return phi;
 403     }
 404   }
 405   // Check if an appropriate new value phi already exists.
 406   Node* new_phi = value_phis->find(mem->_idx);
 407   if (new_phi != NULL)
 408     return new_phi;
 409 
 410   if (level <= 0) {
 411     return NULL; // Give up: phi tree too deep
 412   }
 413   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 414   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 415 
 416   uint length = mem->req();
 417   GrowableArray <Node *> values(length, length, NULL, false);
 418 
 419   // create a new Phi for the value
 420   PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
 421   transform_later(phi);
 422   value_phis->push(phi, mem->_idx);
 423 
 424   for (uint j = 1; j < length; j++) {
 425     Node *in = mem->in(j);
 426     if (in == NULL || in->is_top()) {
 427       values.at_put(j, in);
 428     } else  {
 429       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
 430       if (val == start_mem || val == alloc_mem) {
 431         // hit a sentinel, return appropriate 0 value
 432         values.at_put(j, _igvn.zerocon(ft));
 433         continue;
 434       }
 435       if (val->is_Initialize()) {
 436         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 437       }
 438       if (val == NULL) {
 439         return NULL;  // can't find a value on this path
 440       }
 441       if (val == mem) {
 442         values.at_put(j, mem);
 443       } else if (val->is_Store()) {
 444         values.at_put(j, val->in(MemNode::ValueIn));
 445       } else if(val->is_Proj() && val->in(0) == alloc) {
 446         values.at_put(j, _igvn.zerocon(ft));
 447       } else if (val->is_Phi()) {
 448         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
 449         if (val == NULL) {
 450           return NULL;
 451         }
 452         values.at_put(j, val);
 453       } else if (val->Opcode() == Op_SCMemProj) {
 454         assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
 455         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 456         return NULL;
 457       } else {
 458 #ifdef ASSERT
 459         val->dump();
 460         assert(false, "unknown node on this path");
 461 #endif
 462         return NULL;  // unknown node on this path
 463       }
 464     }
 465   }
 466   // Set Phi's inputs
 467   for (uint j = 1; j < length; j++) {
 468     if (values.at(j) == mem) {
 469       phi->init_req(j, phi);
 470     } else {
 471       phi->init_req(j, values.at(j));
 472     }
 473   }
 474   return phi;
 475 }
 476 
 477 // Search the last value stored into the object's field.
 478 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
 479   assert(adr_t->is_known_instance_field(), "instance required");
 480   int instance_id = adr_t->instance_id();
 481   assert((uint)instance_id == alloc->_idx, "wrong allocation");
 482 
 483   int alias_idx = C->get_alias_index(adr_t);
 484   int offset = adr_t->offset();
 485   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 486   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
 487   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 488   Arena *a = Thread::current()->resource_area();
 489   VectorSet visited(a);
 490 
 491 
 492   bool done = sfpt_mem == alloc_mem;
 493   Node *mem = sfpt_mem;
 494   while (!done) {
 495     if (visited.test_set(mem->_idx)) {
 496       return NULL;  // found a loop, give up
 497     }
 498     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
 499     if (mem == start_mem || mem == alloc_mem) {
 500       done = true;  // hit a sentinel, return appropriate 0 value
 501     } else if (mem->is_Initialize()) {
 502       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 503       if (mem == NULL) {
 504         done = true; // Something go wrong.
 505       } else if (mem->is_Store()) {
 506         const TypePtr* atype = mem->as_Store()->adr_type();
 507         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 508         done = true;
 509       }
 510     } else if (mem->is_Store()) {
 511       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 512       assert(atype != NULL, "address type must be oopptr");
 513       assert(C->get_alias_index(atype) == alias_idx &&
 514              atype->is_known_instance_field() && atype->offset() == offset &&
 515              atype->instance_id() == instance_id, "store is correct memory slice");
 516       done = true;
 517     } else if (mem->is_Phi()) {
 518       // try to find a phi's unique input
 519       Node *unique_input = NULL;
 520       Node *top = C->top();
 521       for (uint i = 1; i < mem->req(); i++) {
 522         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
 523         if (n == NULL || n == top || n == mem) {
 524           continue;
 525         } else if (unique_input == NULL) {
 526           unique_input = n;
 527         } else if (unique_input != n) {
 528           unique_input = top;
 529           break;
 530         }
 531       }
 532       if (unique_input != NULL && unique_input != top) {
 533         mem = unique_input;
 534       } else {
 535         done = true;
 536       }
 537     } else {
 538       assert(false, "unexpected node");
 539     }
 540   }
 541   if (mem != NULL) {
 542     if (mem == start_mem || mem == alloc_mem) {
 543       // hit a sentinel, return appropriate 0 value
 544       return _igvn.zerocon(ft);
 545     } else if (mem->is_Store()) {
 546       return mem->in(MemNode::ValueIn);
 547     } else if (mem->is_Phi()) {
 548       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 549       Node_Stack value_phis(a, 8);
 550       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
 551       if (phi != NULL) {
 552         return phi;
 553       } else {
 554         // Kill all new Phis
 555         while(value_phis.is_nonempty()) {
 556           Node* n = value_phis.node();
 557           _igvn.replace_node(n, C->top());
 558           value_phis.pop();
 559         }
 560       }
 561     }
 562   }
 563   // Something go wrong.
 564   return NULL;
 565 }
 566 
 567 // Check the possibility of scalar replacement.
 568 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 569   //  Scan the uses of the allocation to check for anything that would
 570   //  prevent us from eliminating it.
 571   NOT_PRODUCT( const char* fail_eliminate = NULL; )
 572   DEBUG_ONLY( Node* disq_node = NULL; )
 573   bool  can_eliminate = true;
 574 
 575   Node* res = alloc->result_cast();
 576   const TypeOopPtr* res_type = NULL;
 577   if (res == NULL) {
 578     // All users were eliminated.
 579   } else if (!res->is_CheckCastPP()) {
 580     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 581     can_eliminate = false;
 582   } else {
 583     res_type = _igvn.type(res)->isa_oopptr();
 584     if (res_type == NULL) {
 585       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 586       can_eliminate = false;
 587     } else if (res_type->isa_aryptr()) {
 588       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 589       if (length < 0) {
 590         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 591         can_eliminate = false;
 592       }
 593     }
 594   }
 595 
 596   if (can_eliminate && res != NULL) {
 597     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
 598                                j < jmax && can_eliminate; j++) {
 599       Node* use = res->fast_out(j);
 600 
 601       if (use->is_AddP()) {
 602         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
 603         int offset = addp_type->offset();
 604 
 605         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 606           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
 607           can_eliminate = false;
 608           break;
 609         }
 610         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 611                                    k < kmax && can_eliminate; k++) {
 612           Node* n = use->fast_out(k);
 613           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
 614             DEBUG_ONLY(disq_node = n;)
 615             if (n->is_Load() || n->is_LoadStore()) {
 616               NOT_PRODUCT(fail_eliminate = "Field load";)
 617             } else {
 618               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
 619             }
 620             can_eliminate = false;
 621           }
 622         }
 623       } else if (use->is_SafePoint()) {
 624         SafePointNode* sfpt = use->as_SafePoint();
 625         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 626           // Object is passed as argument.
 627           DEBUG_ONLY(disq_node = use;)
 628           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 629           can_eliminate = false;
 630         }
 631         Node* sfptMem = sfpt->memory();
 632         if (sfptMem == NULL || sfptMem->is_top()) {
 633           DEBUG_ONLY(disq_node = use;)
 634           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
 635           can_eliminate = false;
 636         } else {
 637           safepoints.append_if_missing(sfpt);
 638         }
 639       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 640         if (use->is_Phi()) {
 641           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 642             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 643           } else {
 644             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 645           }
 646           DEBUG_ONLY(disq_node = use;)
 647         } else {
 648           if (use->Opcode() == Op_Return) {
 649             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 650           }else {
 651             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 652           }
 653           DEBUG_ONLY(disq_node = use;)
 654         }
 655         can_eliminate = false;
 656       }
 657     }
 658   }
 659 
 660 #ifndef PRODUCT
 661   if (PrintEliminateAllocations) {
 662     if (can_eliminate) {
 663       tty->print("Scalar ");
 664       if (res == NULL)
 665         alloc->dump();
 666       else
 667         res->dump();
 668     } else if (alloc->_is_scalar_replaceable) {
 669       tty->print("NotScalar (%s)", fail_eliminate);
 670       if (res == NULL)
 671         alloc->dump();
 672       else
 673         res->dump();
 674 #ifdef ASSERT
 675       if (disq_node != NULL) {
 676           tty->print("  >>>> ");
 677           disq_node->dump();
 678       }
 679 #endif /*ASSERT*/
 680     }
 681   }
 682 #endif
 683   return can_eliminate;
 684 }
 685 
 686 // Do scalar replacement.
 687 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 688   GrowableArray <SafePointNode *> safepoints_done;
 689 
 690   ciKlass* klass = NULL;
 691   ciInstanceKlass* iklass = NULL;
 692   int nfields = 0;
 693   int array_base;
 694   int element_size;
 695   BasicType basic_elem_type;
 696   ciType* elem_type;
 697 
 698   Node* res = alloc->result_cast();
 699   assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result");
 700   const TypeOopPtr* res_type = NULL;
 701   if (res != NULL) { // Could be NULL when there are no users
 702     res_type = _igvn.type(res)->isa_oopptr();
 703   }
 704 
 705   if (res != NULL) {
 706     klass = res_type->klass();
 707     if (res_type->isa_instptr()) {
 708       // find the fields of the class which will be needed for safepoint debug information
 709       assert(klass->is_instance_klass(), "must be an instance klass.");
 710       iklass = klass->as_instance_klass();
 711       nfields = iklass->nof_nonstatic_fields();
 712     } else {
 713       // find the array's elements which will be needed for safepoint debug information
 714       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 715       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
 716       elem_type = klass->as_array_klass()->element_type();
 717       basic_elem_type = elem_type->basic_type();
 718       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 719       element_size = type2aelembytes(basic_elem_type);
 720     }
 721   }
 722   //
 723   // Process the safepoint uses
 724   //
 725   while (safepoints.length() > 0) {
 726     SafePointNode* sfpt = safepoints.pop();
 727     Node* mem = sfpt->memory();
 728     assert(sfpt->jvms() != NULL, "missed JVMS");
 729     // Fields of scalar objs are referenced only at the end
 730     // of regular debuginfo at the last (youngest) JVMS.
 731     // Record relative start index.
 732     uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
 733     SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
 734 #ifdef ASSERT
 735                                                  alloc,
 736 #endif
 737                                                  first_ind, nfields);
 738     sobj->init_req(0, C->root());
 739     transform_later(sobj);
 740 
 741     // Scan object's fields adding an input to the safepoint for each field.
 742     for (int j = 0; j < nfields; j++) {
 743       intptr_t offset;
 744       ciField* field = NULL;
 745       if (iklass != NULL) {
 746         field = iklass->nonstatic_field_at(j);
 747         offset = field->offset();
 748         elem_type = field->type();
 749         basic_elem_type = field->layout_type();
 750       } else {
 751         offset = array_base + j * (intptr_t)element_size;
 752       }
 753 
 754       const Type *field_type;
 755       // The next code is taken from Parse::do_get_xxx().
 756       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
 757         if (!elem_type->is_loaded()) {
 758           field_type = TypeInstPtr::BOTTOM;
 759         } else if (field != NULL && field->is_constant() && field->is_static()) {
 760           // This can happen if the constant oop is non-perm.
 761           ciObject* con = field->constant_value().as_object();
 762           // Do not "join" in the previous type; it doesn't add value,
 763           // and may yield a vacuous result if the field is of interface type.
 764           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 765           assert(field_type != NULL, "field singleton type must be consistent");
 766         } else {
 767           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 768         }
 769         if (UseCompressedOops) {
 770           field_type = field_type->make_narrowoop();
 771           basic_elem_type = T_NARROWOOP;
 772         }
 773       } else {
 774         field_type = Type::get_const_basic_type(basic_elem_type);
 775       }
 776 
 777       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
 778 
 779       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
 780       if (field_val == NULL) {
 781         // We weren't able to find a value for this field,
 782         // give up on eliminating this allocation.
 783 
 784         // Remove any extra entries we added to the safepoint.
 785         uint last = sfpt->req() - 1;
 786         for (int k = 0;  k < j; k++) {
 787           sfpt->del_req(last--);
 788         }
 789         _igvn._worklist.push(sfpt);
 790         // rollback processed safepoints
 791         while (safepoints_done.length() > 0) {
 792           SafePointNode* sfpt_done = safepoints_done.pop();
 793           // remove any extra entries we added to the safepoint
 794           last = sfpt_done->req() - 1;
 795           for (int k = 0;  k < nfields; k++) {
 796             sfpt_done->del_req(last--);
 797           }
 798           JVMState *jvms = sfpt_done->jvms();
 799           jvms->set_endoff(sfpt_done->req());
 800           // Now make a pass over the debug information replacing any references
 801           // to SafePointScalarObjectNode with the allocated object.
 802           int start = jvms->debug_start();
 803           int end   = jvms->debug_end();
 804           for (int i = start; i < end; i++) {
 805             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 806               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 807               if (scobj->first_index(jvms) == sfpt_done->req() &&
 808                   scobj->n_fields() == (uint)nfields) {
 809                 assert(scobj->alloc() == alloc, "sanity");
 810                 sfpt_done->set_req(i, res);
 811               }
 812             }
 813           }
 814           _igvn._worklist.push(sfpt_done);
 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 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     _igvn._worklist.push(sfpt);
 856     safepoints_done.append_if_missing(sfpt); // keep it for rollback
 857   }
 858   return true;
 859 }
 860 
 861 // Process users of eliminated allocation.
 862 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
 863   Node* res = alloc->result_cast();
 864   if (res != NULL) {
 865     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
 866       Node *use = res->last_out(j);
 867       uint oc1 = res->outcnt();
 868 
 869       if (use->is_AddP()) {
 870         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
 871           Node *n = use->last_out(k);
 872           uint oc2 = use->outcnt();
 873           if (n->is_Store()) {
 874 #ifdef ASSERT
 875             // Verify that there is no dependent MemBarVolatile nodes,
 876             // they should be removed during IGVN, see MemBarNode::Ideal().
 877             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
 878                                        p < pmax; p++) {
 879               Node* mb = n->fast_out(p);
 880               assert(mb->is_Initialize() || !mb->is_MemBar() ||
 881                      mb->req() <= MemBarNode::Precedent ||
 882                      mb->in(MemBarNode::Precedent) != n,
 883                      "MemBarVolatile should be eliminated for non-escaping object");
 884             }
 885 #endif
 886             _igvn.replace_node(n, n->in(MemNode::Memory));
 887           } else {
 888             eliminate_card_mark(n);
 889           }
 890           k -= (oc2 - use->outcnt());
 891         }
 892       } else {
 893         eliminate_card_mark(use);
 894       }
 895       j -= (oc1 - res->outcnt());
 896     }
 897     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
 898     _igvn.remove_dead_node(res);
 899   }
 900 
 901   //
 902   // Process other users of allocation's projections
 903   //
 904   if (_resproj != NULL && _resproj->outcnt() != 0) {
 905     // First disconnect stores captured by Initialize node.
 906     // If Initialize node is eliminated first in the following code,
 907     // it will kill such stores and DUIterator_Last will assert.
 908     for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax);  j < jmax; j++) {
 909       Node *use = _resproj->fast_out(j);
 910       if (use->is_AddP()) {
 911         // raw memory addresses used only by the initialization
 912         _igvn.replace_node(use, C->top());
 913         --j; --jmax;
 914       }
 915     }
 916     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
 917       Node *use = _resproj->last_out(j);
 918       uint oc1 = _resproj->outcnt();
 919       if (use->is_Initialize()) {
 920         // Eliminate Initialize node.
 921         InitializeNode *init = use->as_Initialize();
 922         assert(init->outcnt() <= 2, "only a control and memory projection expected");
 923         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
 924         if (ctrl_proj != NULL) {
 925            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
 926           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
 927         }
 928         Node *mem_proj = init->proj_out(TypeFunc::Memory);
 929         if (mem_proj != NULL) {
 930           Node *mem = init->in(TypeFunc::Memory);
 931 #ifdef ASSERT
 932           if (mem->is_MergeMem()) {
 933             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
 934           } else {
 935             assert(mem == _memproj_fallthrough, "allocation memory projection");
 936           }
 937 #endif
 938           _igvn.replace_node(mem_proj, mem);
 939         }
 940       } else  {
 941         assert(false, "only Initialize or AddP expected");
 942       }
 943       j -= (oc1 - _resproj->outcnt());
 944     }
 945   }
 946   if (_fallthroughcatchproj != NULL) {
 947     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
 948   }
 949   if (_memproj_fallthrough != NULL) {
 950     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
 951   }
 952   if (_memproj_catchall != NULL) {
 953     _igvn.replace_node(_memproj_catchall, C->top());
 954   }
 955   if (_ioproj_fallthrough != NULL) {
 956     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
 957   }
 958   if (_ioproj_catchall != NULL) {
 959     _igvn.replace_node(_ioproj_catchall, C->top());
 960   }
 961   if (_catchallcatchproj != NULL) {
 962     _igvn.replace_node(_catchallcatchproj, C->top());
 963   }
 964 }
 965 
 966 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
 967   // Don't do scalar replacement if the frame can be popped by JVMTI:
 968   // if reallocation fails during deoptimization we'll pop all
 969   // interpreter frames for this compiled frame and that won't play
 970   // nice with JVMTI popframe.
 971   if (!EliminateAllocations || JvmtiExport::can_pop_frame() || !alloc->_is_non_escaping) {
 972     return false;
 973   }
 974   Node* klass = alloc->in(AllocateNode::KlassNode);
 975   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
 976   Node* res = alloc->result_cast();
 977   // Eliminate boxing allocations which are not used
 978   // regardless scalar replacable status.
 979   bool boxing_alloc = C->eliminate_boxing() &&
 980                       tklass->klass()->is_instance_klass()  &&
 981                       tklass->klass()->as_instance_klass()->is_box_klass();
 982   if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
 983     return false;
 984   }
 985 
 986   extract_call_projections(alloc);
 987 
 988   GrowableArray <SafePointNode *> safepoints;
 989   if (!can_eliminate_allocation(alloc, safepoints)) {
 990     return false;
 991   }
 992 
 993   if (!alloc->_is_scalar_replaceable) {
 994     assert(res == NULL, "sanity");
 995     // We can only eliminate allocation if all debug info references
 996     // are already replaced with SafePointScalarObject because
 997     // we can't search for a fields value without instance_id.
 998     if (safepoints.length() > 0) {
 999       return false;
1000     }
1001   }
1002 
1003   if (!scalar_replacement(alloc, safepoints)) {
1004     return false;
1005   }
1006 
1007   CompileLog* log = C->log();
1008   if (log != NULL) {
1009     log->head("eliminate_allocation type='%d'",
1010               log->identify(tklass->klass()));
1011     JVMState* p = alloc->jvms();
1012     while (p != NULL) {
1013       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1014       p = p->caller();
1015     }
1016     log->tail("eliminate_allocation");
1017   }
1018 
1019   process_users_of_allocation(alloc);
1020 
1021 #ifndef PRODUCT
1022   if (PrintEliminateAllocations) {
1023     if (alloc->is_AllocateArray())
1024       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1025     else
1026       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1027   }
1028 #endif
1029 
1030   return true;
1031 }
1032 
1033 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1034   // EA should remove all uses of non-escaping boxing node.
1035   if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
1036     return false;
1037   }
1038 
1039   assert(boxing->result_cast() == NULL, "unexpected boxing node result");
1040 
1041   extract_call_projections(boxing);
1042 
1043   const TypeTuple* r = boxing->tf()->range();
1044   assert(r->cnt() > TypeFunc::Parms, "sanity");
1045   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1046   assert(t != NULL, "sanity");
1047 
1048   CompileLog* log = C->log();
1049   if (log != NULL) {
1050     log->head("eliminate_boxing type='%d'",
1051               log->identify(t->klass()));
1052     JVMState* p = boxing->jvms();
1053     while (p != NULL) {
1054       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1055       p = p->caller();
1056     }
1057     log->tail("eliminate_boxing");
1058   }
1059 
1060   process_users_of_allocation(boxing);
1061 
1062 #ifndef PRODUCT
1063   if (PrintEliminateAllocations) {
1064     tty->print("++++ Eliminated: %d ", boxing->_idx);
1065     boxing->method()->print_short_name(tty);
1066     tty->cr();
1067   }
1068 #endif
1069 
1070   return true;
1071 }
1072 
1073 //---------------------------set_eden_pointers-------------------------
1074 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1075   if (UseTLAB) {                // Private allocation: load from TLS
1076     Node* thread = transform_later(new ThreadLocalNode());
1077     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1078     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1079     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1080     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1081   } else {                      // Shared allocation: load from globals
1082     CollectedHeap* ch = Universe::heap();
1083     address top_adr = (address)ch->top_addr();
1084     address end_adr = (address)ch->end_addr();
1085     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1086     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1087   }
1088 }
1089 
1090 
1091 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1092   Node* adr = basic_plus_adr(base, offset);
1093   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1094   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1095   transform_later(value);
1096   return value;
1097 }
1098 
1099 
1100 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1101   Node* adr = basic_plus_adr(base, offset);
1102   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
1103   transform_later(mem);
1104   return mem;
1105 }
1106 
1107 //=============================================================================
1108 //
1109 //                              A L L O C A T I O N
1110 //
1111 // Allocation attempts to be fast in the case of frequent small objects.
1112 // It breaks down like this:
1113 //
1114 // 1) Size in doublewords is computed.  This is a constant for objects and
1115 // variable for most arrays.  Doubleword units are used to avoid size
1116 // overflow of huge doubleword arrays.  We need doublewords in the end for
1117 // rounding.
1118 //
1119 // 2) Size is checked for being 'too large'.  Too-large allocations will go
1120 // the slow path into the VM.  The slow path can throw any required
1121 // exceptions, and does all the special checks for very large arrays.  The
1122 // size test can constant-fold away for objects.  For objects with
1123 // finalizers it constant-folds the otherway: you always go slow with
1124 // finalizers.
1125 //
1126 // 3) If NOT using TLABs, this is the contended loop-back point.
1127 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
1128 //
1129 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
1130 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
1131 // "size*8" we always enter the VM, where "largish" is a constant picked small
1132 // enough that there's always space between the eden max and 4Gig (old space is
1133 // there so it's quite large) and large enough that the cost of entering the VM
1134 // is dwarfed by the cost to initialize the space.
1135 //
1136 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1137 // down.  If contended, repeat at step 3.  If using TLABs normal-store
1138 // adjusted heap top back down; there is no contention.
1139 //
1140 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
1141 // fields.
1142 //
1143 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1144 // oop flavor.
1145 //
1146 //=============================================================================
1147 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1148 // Allocations bigger than this always go the slow route.
1149 // This value must be small enough that allocation attempts that need to
1150 // trigger exceptions go the slow route.  Also, it must be small enough so
1151 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1152 //=============================================================================j//
1153 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1154 // The allocator will coalesce int->oop copies away.  See comment in
1155 // coalesce.cpp about how this works.  It depends critically on the exact
1156 // code shape produced here, so if you are changing this code shape
1157 // make sure the GC info for the heap-top is correct in and around the
1158 // slow-path call.
1159 //
1160 
1161 void PhaseMacroExpand::expand_allocate_common(
1162             AllocateNode* alloc, // allocation node to be expanded
1163             Node* length,  // array length for an array allocation
1164             const TypeFunc* slow_call_type, // Type of slow call
1165             address slow_call_address  // Address of slow call
1166     )
1167 {
1168 
1169   Node* ctrl = alloc->in(TypeFunc::Control);
1170   Node* mem  = alloc->in(TypeFunc::Memory);
1171   Node* i_o  = alloc->in(TypeFunc::I_O);
1172   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
1173   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
1174   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1175 
1176   assert(ctrl != NULL, "must have control");
1177   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1178   // they will not be used if "always_slow" is set
1179   enum { slow_result_path = 1, fast_result_path = 2 };
1180   Node *result_region;
1181   Node *result_phi_rawmem;
1182   Node *result_phi_rawoop;
1183   Node *result_phi_i_o;
1184 
1185   // The initial slow comparison is a size check, the comparison
1186   // we want to do is a BoolTest::gt
1187   bool always_slow = false;
1188   int tv = _igvn.find_int_con(initial_slow_test, -1);
1189   if (tv >= 0) {
1190     always_slow = (tv == 1);
1191     initial_slow_test = NULL;
1192   } else {
1193     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1194   }
1195 
1196   if (C->env()->dtrace_alloc_probes() ||
1197       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc())) {
1198     // Force slow-path allocation
1199     always_slow = true;
1200     initial_slow_test = NULL;
1201   }
1202 
1203 
1204   enum { too_big_or_final_path = 1, need_gc_path = 2 };
1205   Node *slow_region = NULL;
1206   Node *toobig_false = ctrl;
1207 
1208   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1209   // generate the initial test if necessary
1210   if (initial_slow_test != NULL ) {
1211     slow_region = new RegionNode(3);
1212 
1213     // Now make the initial failure test.  Usually a too-big test but
1214     // might be a TRUE for finalizers or a fancy class check for
1215     // newInstance0.
1216     IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1217     transform_later(toobig_iff);
1218     // Plug the failing-too-big test into the slow-path region
1219     Node *toobig_true = new IfTrueNode( toobig_iff );
1220     transform_later(toobig_true);
1221     slow_region    ->init_req( too_big_or_final_path, toobig_true );
1222     toobig_false = new IfFalseNode( toobig_iff );
1223     transform_later(toobig_false);
1224   } else {         // No initial test, just fall into next case
1225     toobig_false = ctrl;
1226     debug_only(slow_region = NodeSentinel);
1227   }
1228 
1229   Node *slow_mem = mem;  // save the current memory state for slow path
1230   // generate the fast allocation code unless we know that the initial test will always go slow
1231   if (!always_slow) {
1232     // Fast path modifies only raw memory.
1233     if (mem->is_MergeMem()) {
1234       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1235     }
1236 
1237     Node* eden_top_adr;
1238     Node* eden_end_adr;
1239 
1240     set_eden_pointers(eden_top_adr, eden_end_adr);
1241 
1242     // Load Eden::end.  Loop invariant and hoisted.
1243     //
1244     // Note: We set the control input on "eden_end" and "old_eden_top" when using
1245     //       a TLAB to work around a bug where these values were being moved across
1246     //       a safepoint.  These are not oops, so they cannot be include in the oop
1247     //       map, but they can be changed by a GC.   The proper way to fix this would
1248     //       be to set the raw memory state when generating a  SafepointNode.  However
1249     //       this will require extensive changes to the loop optimization in order to
1250     //       prevent a degradation of the optimization.
1251     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
1252     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1253 
1254     // allocate the Region and Phi nodes for the result
1255     result_region = new RegionNode(3);
1256     result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1257     result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1258     result_phi_i_o    = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1259 
1260     // We need a Region for the loop-back contended case.
1261     enum { fall_in_path = 1, contended_loopback_path = 2 };
1262     Node *contended_region;
1263     Node *contended_phi_rawmem;
1264     if (UseTLAB) {
1265       contended_region = toobig_false;
1266       contended_phi_rawmem = mem;
1267     } else {
1268       contended_region = new RegionNode(3);
1269       contended_phi_rawmem = new PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1270       // Now handle the passing-too-big test.  We fall into the contended
1271       // loop-back merge point.
1272       contended_region    ->init_req(fall_in_path, toobig_false);
1273       contended_phi_rawmem->init_req(fall_in_path, mem);
1274       transform_later(contended_region);
1275       transform_later(contended_phi_rawmem);
1276     }
1277 
1278     // Load(-locked) the heap top.
1279     // See note above concerning the control input when using a TLAB
1280     Node *old_eden_top = UseTLAB
1281       ? new LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered)
1282       : new LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr, MemNode::acquire);
1283 
1284     transform_later(old_eden_top);
1285     // Add to heap top to get a new heap top
1286     Node *new_eden_top = new AddPNode(top(), old_eden_top, size_in_bytes);
1287     transform_later(new_eden_top);
1288     // Check for needing a GC; compare against heap end
1289     Node *needgc_cmp = new CmpPNode(new_eden_top, eden_end);
1290     transform_later(needgc_cmp);
1291     Node *needgc_bol = new BoolNode(needgc_cmp, BoolTest::ge);
1292     transform_later(needgc_bol);
1293     IfNode *needgc_iff = new IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1294     transform_later(needgc_iff);
1295 
1296     // Plug the failing-heap-space-need-gc test into the slow-path region
1297     Node *needgc_true = new IfTrueNode(needgc_iff);
1298     transform_later(needgc_true);
1299     if (initial_slow_test) {
1300       slow_region->init_req(need_gc_path, needgc_true);
1301       // This completes all paths into the slow merge point
1302       transform_later(slow_region);
1303     } else {                      // No initial slow path needed!
1304       // Just fall from the need-GC path straight into the VM call.
1305       slow_region = needgc_true;
1306     }
1307     // No need for a GC.  Setup for the Store-Conditional
1308     Node *needgc_false = new IfFalseNode(needgc_iff);
1309     transform_later(needgc_false);
1310 
1311     // Grab regular I/O before optional prefetch may change it.
1312     // Slow-path does no I/O so just set it to the original I/O.
1313     result_phi_i_o->init_req(slow_result_path, i_o);
1314 
1315     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1316                               old_eden_top, new_eden_top, length);
1317 
1318     // Name successful fast-path variables
1319     Node* fast_oop = old_eden_top;
1320     Node* fast_oop_ctrl;
1321     Node* fast_oop_rawmem;
1322 
1323     // Store (-conditional) the modified eden top back down.
1324     // StorePConditional produces flags for a test PLUS a modified raw
1325     // memory state.
1326     if (UseTLAB) {
1327       Node* store_eden_top =
1328         new StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1329                               TypeRawPtr::BOTTOM, new_eden_top, MemNode::unordered);
1330       transform_later(store_eden_top);
1331       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1332       fast_oop_rawmem = store_eden_top;
1333     } else {
1334       Node* store_eden_top =
1335         new StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1336                                          new_eden_top, fast_oop/*old_eden_top*/);
1337       transform_later(store_eden_top);
1338       Node *contention_check = new BoolNode(store_eden_top, BoolTest::ne);
1339       transform_later(contention_check);
1340       store_eden_top = new SCMemProjNode(store_eden_top);
1341       transform_later(store_eden_top);
1342 
1343       // If not using TLABs, check to see if there was contention.
1344       IfNode *contention_iff = new IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1345       transform_later(contention_iff);
1346       Node *contention_true = new IfTrueNode(contention_iff);
1347       transform_later(contention_true);
1348       // If contention, loopback and try again.
1349       contended_region->init_req(contended_loopback_path, contention_true);
1350       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1351 
1352       // Fast-path succeeded with no contention!
1353       Node *contention_false = new IfFalseNode(contention_iff);
1354       transform_later(contention_false);
1355       fast_oop_ctrl = contention_false;
1356 
1357       // Bump total allocated bytes for this thread
1358       Node* thread = new ThreadLocalNode();
1359       transform_later(thread);
1360       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1361                                              in_bytes(JavaThread::allocated_bytes_offset()));
1362       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1363                                     0, TypeLong::LONG, T_LONG);
1364 #ifdef _LP64
1365       Node* alloc_size = size_in_bytes;
1366 #else
1367       Node* alloc_size = new ConvI2LNode(size_in_bytes);
1368       transform_later(alloc_size);
1369 #endif
1370       Node* new_alloc_bytes = new AddLNode(alloc_bytes, alloc_size);
1371       transform_later(new_alloc_bytes);
1372       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1373                                    0, new_alloc_bytes, T_LONG);
1374     }
1375 
1376     InitializeNode* init = alloc->initialization();
1377     fast_oop_rawmem = initialize_object(alloc,
1378                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1379                                         klass_node, length, size_in_bytes);
1380 
1381     // If initialization is performed by an array copy, any required
1382     // MemBarStoreStore was already added. If the object does not
1383     // escape no need for a MemBarStoreStore. Otherwise we need a
1384     // MemBarStoreStore so that stores that initialize this object
1385     // can't be reordered with a subsequent store that makes this
1386     // object accessible by other threads.
1387     if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
1388       if (init == NULL || init->req() < InitializeNode::RawStores) {
1389         // No InitializeNode or no stores captured by zeroing
1390         // elimination. Simply add the MemBarStoreStore after object
1391         // initialization.
1392         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1393         transform_later(mb);
1394 
1395         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1396         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1397         fast_oop_ctrl = new ProjNode(mb,TypeFunc::Control);
1398         transform_later(fast_oop_ctrl);
1399         fast_oop_rawmem = new ProjNode(mb,TypeFunc::Memory);
1400         transform_later(fast_oop_rawmem);
1401       } else {
1402         // Add the MemBarStoreStore after the InitializeNode so that
1403         // all stores performing the initialization that were moved
1404         // before the InitializeNode happen before the storestore
1405         // barrier.
1406 
1407         Node* init_ctrl = init->proj_out(TypeFunc::Control);
1408         Node* init_mem = init->proj_out(TypeFunc::Memory);
1409 
1410         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1411         transform_later(mb);
1412 
1413         Node* ctrl = new ProjNode(init,TypeFunc::Control);
1414         transform_later(ctrl);
1415         Node* mem = new ProjNode(init,TypeFunc::Memory);
1416         transform_later(mem);
1417 
1418         // The MemBarStoreStore depends on control and memory coming
1419         // from the InitializeNode
1420         mb->init_req(TypeFunc::Memory, mem);
1421         mb->init_req(TypeFunc::Control, ctrl);
1422 
1423         ctrl = new ProjNode(mb,TypeFunc::Control);
1424         transform_later(ctrl);
1425         mem = new ProjNode(mb,TypeFunc::Memory);
1426         transform_later(mem);
1427 
1428         // All nodes that depended on the InitializeNode for control
1429         // and memory must now depend on the MemBarNode that itself
1430         // depends on the InitializeNode
1431         _igvn.replace_node(init_ctrl, ctrl);
1432         _igvn.replace_node(init_mem, mem);
1433       }
1434     }
1435 
1436     if (C->env()->dtrace_extended_probes()) {
1437       // Slow-path call
1438       int size = TypeFunc::Parms + 2;
1439       CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1440                                             CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1441                                             "dtrace_object_alloc",
1442                                             TypeRawPtr::BOTTOM);
1443 
1444       // Get base of thread-local storage area
1445       Node* thread = new ThreadLocalNode();
1446       transform_later(thread);
1447 
1448       call->init_req(TypeFunc::Parms+0, thread);
1449       call->init_req(TypeFunc::Parms+1, fast_oop);
1450       call->init_req(TypeFunc::Control, fast_oop_ctrl);
1451       call->init_req(TypeFunc::I_O    , top()); // does no i/o
1452       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1453       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1454       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1455       transform_later(call);
1456       fast_oop_ctrl = new ProjNode(call,TypeFunc::Control);
1457       transform_later(fast_oop_ctrl);
1458       fast_oop_rawmem = new ProjNode(call,TypeFunc::Memory);
1459       transform_later(fast_oop_rawmem);
1460     }
1461 
1462     // Plug in the successful fast-path into the result merge point
1463     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
1464     result_phi_rawoop->init_req(fast_result_path, fast_oop);
1465     result_phi_i_o   ->init_req(fast_result_path, i_o);
1466     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1467   } else {
1468     slow_region = ctrl;
1469     result_phi_i_o = i_o; // Rename it to use in the following code.
1470   }
1471 
1472   // Generate slow-path call
1473   CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1474                                OptoRuntime::stub_name(slow_call_address),
1475                                alloc->jvms()->bci(),
1476                                TypePtr::BOTTOM);
1477   call->init_req( TypeFunc::Control, slow_region );
1478   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
1479   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1480   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1481   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1482 
1483   call->init_req(TypeFunc::Parms+0, klass_node);
1484   if (length != NULL) {
1485     call->init_req(TypeFunc::Parms+1, length);
1486   }
1487 
1488   // Copy debug information and adjust JVMState information, then replace
1489   // allocate node with the call
1490   copy_call_debug_info((CallNode *) alloc,  call);
1491   if (!always_slow) {
1492     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1493   } else {
1494     // Hook i_o projection to avoid its elimination during allocation
1495     // replacement (when only a slow call is generated).
1496     call->set_req(TypeFunc::I_O, result_phi_i_o);
1497   }
1498   _igvn.replace_node(alloc, call);
1499   transform_later(call);
1500 
1501   // Identify the output projections from the allocate node and
1502   // adjust any references to them.
1503   // The control and io projections look like:
1504   //
1505   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1506   //  Allocate                   Catch
1507   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1508   //
1509   //  We are interested in the CatchProj nodes.
1510   //
1511   extract_call_projections(call);
1512 
1513   // An allocate node has separate memory projections for the uses on
1514   // the control and i_o paths. Replace the control memory projection with
1515   // result_phi_rawmem (unless we are only generating a slow call when
1516   // both memory projections are combined)
1517   if (!always_slow && _memproj_fallthrough != NULL) {
1518     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1519       Node *use = _memproj_fallthrough->fast_out(i);
1520       _igvn.rehash_node_delayed(use);
1521       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1522       // back up iterator
1523       --i;
1524     }
1525   }
1526   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1527   // _memproj_catchall so we end up with a call that has only 1 memory projection.
1528   if (_memproj_catchall != NULL ) {
1529     if (_memproj_fallthrough == NULL) {
1530       _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory);
1531       transform_later(_memproj_fallthrough);
1532     }
1533     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1534       Node *use = _memproj_catchall->fast_out(i);
1535       _igvn.rehash_node_delayed(use);
1536       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1537       // back up iterator
1538       --i;
1539     }
1540     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1541     _igvn.remove_dead_node(_memproj_catchall);
1542   }
1543 
1544   // An allocate node has separate i_o projections for the uses on the control
1545   // and i_o paths. Always replace the control i_o projection with result i_o
1546   // otherwise incoming i_o become dead when only a slow call is generated
1547   // (it is different from memory projections where both projections are
1548   // combined in such case).
1549   if (_ioproj_fallthrough != NULL) {
1550     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1551       Node *use = _ioproj_fallthrough->fast_out(i);
1552       _igvn.rehash_node_delayed(use);
1553       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1554       // back up iterator
1555       --i;
1556     }
1557   }
1558   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1559   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1560   if (_ioproj_catchall != NULL ) {
1561     if (_ioproj_fallthrough == NULL) {
1562       _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O);
1563       transform_later(_ioproj_fallthrough);
1564     }
1565     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1566       Node *use = _ioproj_catchall->fast_out(i);
1567       _igvn.rehash_node_delayed(use);
1568       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1569       // back up iterator
1570       --i;
1571     }
1572     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1573     _igvn.remove_dead_node(_ioproj_catchall);
1574   }
1575 
1576   // if we generated only a slow call, we are done
1577   if (always_slow) {
1578     // Now we can unhook i_o.
1579     if (result_phi_i_o->outcnt() > 1) {
1580       call->set_req(TypeFunc::I_O, top());
1581     } else {
1582       assert(result_phi_i_o->unique_ctrl_out() == call, "");
1583       // Case of new array with negative size known during compilation.
1584       // AllocateArrayNode::Ideal() optimization disconnect unreachable
1585       // following code since call to runtime will throw exception.
1586       // As result there will be no users of i_o after the call.
1587       // Leave i_o attached to this call to avoid problems in preceding graph.
1588     }
1589     return;
1590   }
1591 
1592 
1593   if (_fallthroughcatchproj != NULL) {
1594     ctrl = _fallthroughcatchproj->clone();
1595     transform_later(ctrl);
1596     _igvn.replace_node(_fallthroughcatchproj, result_region);
1597   } else {
1598     ctrl = top();
1599   }
1600   Node *slow_result;
1601   if (_resproj == NULL) {
1602     // no uses of the allocation result
1603     slow_result = top();
1604   } else {
1605     slow_result = _resproj->clone();
1606     transform_later(slow_result);
1607     _igvn.replace_node(_resproj, result_phi_rawoop);
1608   }
1609 
1610   // Plug slow-path into result merge point
1611   result_region    ->init_req( slow_result_path, ctrl );
1612   result_phi_rawoop->init_req( slow_result_path, slow_result);
1613   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1614   transform_later(result_region);
1615   transform_later(result_phi_rawoop);
1616   transform_later(result_phi_rawmem);
1617   transform_later(result_phi_i_o);
1618   // This completes all paths into the result merge point
1619 }
1620 
1621 
1622 // Helper for PhaseMacroExpand::expand_allocate_common.
1623 // Initializes the newly-allocated storage.
1624 Node*
1625 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1626                                     Node* control, Node* rawmem, Node* object,
1627                                     Node* klass_node, Node* length,
1628                                     Node* size_in_bytes) {
1629   InitializeNode* init = alloc->initialization();
1630   // Store the klass & mark bits
1631   Node* mark_node = NULL;
1632   // For now only enable fast locking for non-array types
1633   if (UseBiasedLocking && (length == NULL)) {
1634     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1635   } else {
1636     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1637   }
1638   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1639 
1640   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1641   int header_size = alloc->minimum_header_size();  // conservatively small
1642 
1643   // Array length
1644   if (length != NULL) {         // Arrays need length field
1645     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1646     // conservatively small header size:
1647     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1648     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1649     if (k->is_array_klass())    // we know the exact header size in most cases:
1650       header_size = Klass::layout_helper_header_size(k->layout_helper());
1651   }
1652 
1653   // Clear the object body, if necessary.
1654   if (init == NULL) {
1655     // The init has somehow disappeared; be cautious and clear everything.
1656     //
1657     // This can happen if a node is allocated but an uncommon trap occurs
1658     // immediately.  In this case, the Initialize gets associated with the
1659     // trap, and may be placed in a different (outer) loop, if the Allocate
1660     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
1661     // there can be two Allocates to one Initialize.  The answer in all these
1662     // edge cases is safety first.  It is always safe to clear immediately
1663     // within an Allocate, and then (maybe or maybe not) clear some more later.
1664     if (!ZeroTLAB)
1665       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1666                                             header_size, size_in_bytes,
1667                                             &_igvn);
1668   } else {
1669     if (!init->is_complete()) {
1670       // Try to win by zeroing only what the init does not store.
1671       // We can also try to do some peephole optimizations,
1672       // such as combining some adjacent subword stores.
1673       rawmem = init->complete_stores(control, rawmem, object,
1674                                      header_size, size_in_bytes, &_igvn);
1675     }
1676     // We have no more use for this link, since the AllocateNode goes away:
1677     init->set_req(InitializeNode::RawAddress, top());
1678     // (If we keep the link, it just confuses the register allocator,
1679     // who thinks he sees a real use of the address by the membar.)
1680   }
1681 
1682   return rawmem;
1683 }
1684 
1685 // Generate prefetch instructions for next allocations.
1686 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1687                                         Node*& contended_phi_rawmem,
1688                                         Node* old_eden_top, Node* new_eden_top,
1689                                         Node* length) {
1690    enum { fall_in_path = 1, pf_path = 2 };
1691    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1692       // Generate prefetch allocation with watermark check.
1693       // As an allocation hits the watermark, we will prefetch starting
1694       // at a "distance" away from watermark.
1695 
1696       Node *pf_region = new RegionNode(3);
1697       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1698                                                 TypeRawPtr::BOTTOM );
1699       // I/O is used for Prefetch
1700       Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1701 
1702       Node *thread = new ThreadLocalNode();
1703       transform_later(thread);
1704 
1705       Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1706                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1707       transform_later(eden_pf_adr);
1708 
1709       Node *old_pf_wm = new LoadPNode(needgc_false,
1710                                    contended_phi_rawmem, eden_pf_adr,
1711                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1712                                    MemNode::unordered);
1713       transform_later(old_pf_wm);
1714 
1715       // check against new_eden_top
1716       Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1717       transform_later(need_pf_cmp);
1718       Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1719       transform_later(need_pf_bol);
1720       IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1721                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1722       transform_later(need_pf_iff);
1723 
1724       // true node, add prefetchdistance
1725       Node *need_pf_true = new IfTrueNode( need_pf_iff );
1726       transform_later(need_pf_true);
1727 
1728       Node *need_pf_false = new IfFalseNode( need_pf_iff );
1729       transform_later(need_pf_false);
1730 
1731       Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1732                                     _igvn.MakeConX(AllocatePrefetchDistance) );
1733       transform_later(new_pf_wmt );
1734       new_pf_wmt->set_req(0, need_pf_true);
1735 
1736       Node *store_new_wmt = new StorePNode(need_pf_true,
1737                                        contended_phi_rawmem, eden_pf_adr,
1738                                        TypeRawPtr::BOTTOM, new_pf_wmt,
1739                                        MemNode::unordered);
1740       transform_later(store_new_wmt);
1741 
1742       // adding prefetches
1743       pf_phi_abio->init_req( fall_in_path, i_o );
1744 
1745       Node *prefetch_adr;
1746       Node *prefetch;
1747       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1748       uint step_size = AllocatePrefetchStepSize;
1749       uint distance = 0;
1750 
1751       for ( uint i = 0; i < lines; i++ ) {
1752         prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1753                                             _igvn.MakeConX(distance) );
1754         transform_later(prefetch_adr);
1755         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1756         transform_later(prefetch);
1757         distance += step_size;
1758         i_o = prefetch;
1759       }
1760       pf_phi_abio->set_req( pf_path, i_o );
1761 
1762       pf_region->init_req( fall_in_path, need_pf_false );
1763       pf_region->init_req( pf_path, need_pf_true );
1764 
1765       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1766       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1767 
1768       transform_later(pf_region);
1769       transform_later(pf_phi_rawmem);
1770       transform_later(pf_phi_abio);
1771 
1772       needgc_false = pf_region;
1773       contended_phi_rawmem = pf_phi_rawmem;
1774       i_o = pf_phi_abio;
1775    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1776       // Insert a prefetch for each allocation.
1777       // This code is used for Sparc with BIS.
1778       Node *pf_region = new RegionNode(3);
1779       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1780                                              TypeRawPtr::BOTTOM );
1781       transform_later(pf_region);
1782 
1783       // Generate several prefetch instructions.
1784       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1785       uint step_size = AllocatePrefetchStepSize;
1786       uint distance = AllocatePrefetchDistance;
1787 
1788       // Next cache address.
1789       Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1790                                             _igvn.MakeConX(distance));
1791       transform_later(cache_adr);
1792       cache_adr = new CastP2XNode(needgc_false, cache_adr);
1793       transform_later(cache_adr);
1794       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1795       cache_adr = new AndXNode(cache_adr, mask);
1796       transform_later(cache_adr);
1797       cache_adr = new CastX2PNode(cache_adr);
1798       transform_later(cache_adr);
1799 
1800       // Prefetch
1801       Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1802       prefetch->set_req(0, needgc_false);
1803       transform_later(prefetch);
1804       contended_phi_rawmem = prefetch;
1805       Node *prefetch_adr;
1806       distance = step_size;
1807       for ( uint i = 1; i < lines; i++ ) {
1808         prefetch_adr = new AddPNode( cache_adr, cache_adr,
1809                                             _igvn.MakeConX(distance) );
1810         transform_later(prefetch_adr);
1811         prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1812         transform_later(prefetch);
1813         distance += step_size;
1814         contended_phi_rawmem = prefetch;
1815       }
1816    } else if( AllocatePrefetchStyle > 0 ) {
1817       // Insert a prefetch for each allocation only on the fast-path
1818       Node *prefetch_adr;
1819       Node *prefetch;
1820       // Generate several prefetch instructions.
1821       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1822       uint step_size = AllocatePrefetchStepSize;
1823       uint distance = AllocatePrefetchDistance;
1824       for ( uint i = 0; i < lines; i++ ) {
1825         prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1826                                             _igvn.MakeConX(distance) );
1827         transform_later(prefetch_adr);
1828         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1829         // Do not let it float too high, since if eden_top == eden_end,
1830         // both might be null.
1831         if( i == 0 ) { // Set control for first prefetch, next follows it
1832           prefetch->init_req(0, needgc_false);
1833         }
1834         transform_later(prefetch);
1835         distance += step_size;
1836         i_o = prefetch;
1837       }
1838    }
1839    return i_o;
1840 }
1841 
1842 
1843 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1844   expand_allocate_common(alloc, NULL,
1845                          OptoRuntime::new_instance_Type(),
1846                          OptoRuntime::new_instance_Java());
1847 }
1848 
1849 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1850   Node* length = alloc->in(AllocateNode::ALength);
1851   InitializeNode* init = alloc->initialization();
1852   Node* klass_node = alloc->in(AllocateNode::KlassNode);
1853   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1854   address slow_call_address;  // Address of slow call
1855   if (init != NULL && init->is_complete_with_arraycopy() &&
1856       k->is_type_array_klass()) {
1857     // Don't zero type array during slow allocation in VM since
1858     // it will be initialized later by arraycopy in compiled code.
1859     slow_call_address = OptoRuntime::new_array_nozero_Java();
1860   } else {
1861     slow_call_address = OptoRuntime::new_array_Java();
1862   }
1863   expand_allocate_common(alloc, length,
1864                          OptoRuntime::new_array_Type(),
1865                          slow_call_address);
1866 }
1867 
1868 //-------------------mark_eliminated_box----------------------------------
1869 //
1870 // During EA obj may point to several objects but after few ideal graph
1871 // transformations (CCP) it may point to only one non escaping object
1872 // (but still using phi), corresponding locks and unlocks will be marked
1873 // for elimination. Later obj could be replaced with a new node (new phi)
1874 // and which does not have escape information. And later after some graph
1875 // reshape other locks and unlocks (which were not marked for elimination
1876 // before) are connected to this new obj (phi) but they still will not be
1877 // marked for elimination since new obj has no escape information.
1878 // Mark all associated (same box and obj) lock and unlock nodes for
1879 // elimination if some of them marked already.
1880 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1881   if (oldbox->as_BoxLock()->is_eliminated())
1882     return; // This BoxLock node was processed already.
1883 
1884   // New implementation (EliminateNestedLocks) has separate BoxLock
1885   // node for each locked region so mark all associated locks/unlocks as
1886   // eliminated even if different objects are referenced in one locked region
1887   // (for example, OSR compilation of nested loop inside locked scope).
1888   if (EliminateNestedLocks ||
1889       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
1890     // Box is used only in one lock region. Mark this box as eliminated.
1891     _igvn.hash_delete(oldbox);
1892     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1893      _igvn.hash_insert(oldbox);
1894 
1895     for (uint i = 0; i < oldbox->outcnt(); i++) {
1896       Node* u = oldbox->raw_out(i);
1897       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1898         AbstractLockNode* alock = u->as_AbstractLock();
1899         // Check lock's box since box could be referenced by Lock's debug info.
1900         if (alock->box_node() == oldbox) {
1901           // Mark eliminated all related locks and unlocks.
1902 #ifdef ASSERT
1903           alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4");
1904 #endif
1905           alock->set_non_esc_obj();
1906         }
1907       }
1908     }
1909     return;
1910   }
1911 
1912   // Create new "eliminated" BoxLock node and use it in monitor debug info
1913   // instead of oldbox for the same object.
1914   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1915 
1916   // Note: BoxLock node is marked eliminated only here and it is used
1917   // to indicate that all associated lock and unlock nodes are marked
1918   // for elimination.
1919   newbox->set_eliminated();
1920   transform_later(newbox);
1921 
1922   // Replace old box node with new box for all users of the same object.
1923   for (uint i = 0; i < oldbox->outcnt();) {
1924     bool next_edge = true;
1925 
1926     Node* u = oldbox->raw_out(i);
1927     if (u->is_AbstractLock()) {
1928       AbstractLockNode* alock = u->as_AbstractLock();
1929       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
1930         // Replace Box and mark eliminated all related locks and unlocks.
1931 #ifdef ASSERT
1932         alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5");
1933 #endif
1934         alock->set_non_esc_obj();
1935         _igvn.rehash_node_delayed(alock);
1936         alock->set_box_node(newbox);
1937         next_edge = false;
1938       }
1939     }
1940     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
1941       FastLockNode* flock = u->as_FastLock();
1942       assert(flock->box_node() == oldbox, "sanity");
1943       _igvn.rehash_node_delayed(flock);
1944       flock->set_box_node(newbox);
1945       next_edge = false;
1946     }
1947 
1948     // Replace old box in monitor debug info.
1949     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1950       SafePointNode* sfn = u->as_SafePoint();
1951       JVMState* youngest_jvms = sfn->jvms();
1952       int max_depth = youngest_jvms->depth();
1953       for (int depth = 1; depth <= max_depth; depth++) {
1954         JVMState* jvms = youngest_jvms->of_depth(depth);
1955         int num_mon  = jvms->nof_monitors();
1956         // Loop over monitors
1957         for (int idx = 0; idx < num_mon; idx++) {
1958           Node* obj_node = sfn->monitor_obj(jvms, idx);
1959           Node* box_node = sfn->monitor_box(jvms, idx);
1960           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
1961             int j = jvms->monitor_box_offset(idx);
1962             _igvn.replace_input_of(u, j, newbox);
1963             next_edge = false;
1964           }
1965         }
1966       }
1967     }
1968     if (next_edge) i++;
1969   }
1970 }
1971 
1972 //-----------------------mark_eliminated_locking_nodes-----------------------
1973 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1974   if (EliminateNestedLocks) {
1975     if (alock->is_nested()) {
1976        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
1977        return;
1978     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
1979       // Only Lock node has JVMState needed here.
1980       // Not that preceding claim is documented anywhere else.
1981       if (alock->jvms() != NULL) {
1982         if (alock->as_Lock()->is_nested_lock_region()) {
1983           // Mark eliminated related nested locks and unlocks.
1984           Node* obj = alock->obj_node();
1985           BoxLockNode* box_node = alock->box_node()->as_BoxLock();
1986           assert(!box_node->is_eliminated(), "should not be marked yet");
1987           // Note: BoxLock node is marked eliminated only here
1988           // and it is used to indicate that all associated lock
1989           // and unlock nodes are marked for elimination.
1990           box_node->set_eliminated(); // Box's hash is always NO_HASH here
1991           for (uint i = 0; i < box_node->outcnt(); i++) {
1992             Node* u = box_node->raw_out(i);
1993             if (u->is_AbstractLock()) {
1994               alock = u->as_AbstractLock();
1995               if (alock->box_node() == box_node) {
1996                 // Verify that this Box is referenced only by related locks.
1997                 assert(alock->obj_node()->eqv_uncast(obj), "");
1998                 // Mark all related locks and unlocks.
1999 #ifdef ASSERT
2000                 alock->log_lock_optimization(C, "eliminate_lock_set_nested");
2001 #endif
2002                 alock->set_nested();
2003               }
2004             }
2005           }
2006         } else {
2007 #ifdef ASSERT
2008           alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region");
2009           alock->as_Lock()->is_nested_lock_region_debug(C);
2010 #endif
2011         }
2012       }
2013       return;
2014     }
2015     // Process locks for non escaping object
2016     assert(alock->is_non_esc_obj(), "");
2017   } // EliminateNestedLocks
2018 
2019   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2020     // Look for all locks of this object and mark them and
2021     // corresponding BoxLock nodes as eliminated.
2022     Node* obj = alock->obj_node();
2023     for (uint j = 0; j < obj->outcnt(); j++) {
2024       Node* o = obj->raw_out(j);
2025       if (o->is_AbstractLock() &&
2026           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2027         alock = o->as_AbstractLock();
2028         Node* box = alock->box_node();
2029         // Replace old box node with new eliminated box for all users
2030         // of the same object and mark related locks as eliminated.
2031         mark_eliminated_box(box, obj);
2032       }
2033     }
2034   }
2035 }
2036 
2037 // we have determined that this lock/unlock can be eliminated, we simply
2038 // eliminate the node without expanding it.
2039 //
2040 // Note:  The membar's associated with the lock/unlock are currently not
2041 //        eliminated.  This should be investigated as a future enhancement.
2042 //
2043 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2044 
2045   if (!alock->is_eliminated()) {
2046     return false;
2047   }
2048 #ifdef ASSERT
2049   if (!alock->is_coarsened()) {
2050     // Check that new "eliminated" BoxLock node is created.
2051     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2052     assert(oldbox->is_eliminated(), "should be done already");
2053   }
2054 #endif
2055 
2056   alock->log_lock_optimization(C, "eliminate_lock");
2057 
2058 #ifndef PRODUCT
2059   if (PrintEliminateLocks) {
2060     if (alock->is_Lock()) {
2061       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2062     } else {
2063       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2064     }
2065   }
2066 #endif
2067 
2068   Node* mem  = alock->in(TypeFunc::Memory);
2069   Node* ctrl = alock->in(TypeFunc::Control);
2070 
2071   extract_call_projections(alock);
2072   // There are 2 projections from the lock.  The lock node will
2073   // be deleted when its last use is subsumed below.
2074   assert(alock->outcnt() == 2 &&
2075          _fallthroughproj != NULL &&
2076          _memproj_fallthrough != NULL,
2077          "Unexpected projections from Lock/Unlock");
2078 
2079   Node* fallthroughproj = _fallthroughproj;
2080   Node* memproj_fallthrough = _memproj_fallthrough;
2081 
2082   // The memory projection from a lock/unlock is RawMem
2083   // The input to a Lock is merged memory, so extract its RawMem input
2084   // (unless the MergeMem has been optimized away.)
2085   if (alock->is_Lock()) {
2086     // Seach for MemBarAcquireLock node and delete it also.
2087     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2088     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2089     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2090     Node* memproj = membar->proj_out(TypeFunc::Memory);
2091     _igvn.replace_node(ctrlproj, fallthroughproj);
2092     _igvn.replace_node(memproj, memproj_fallthrough);
2093 
2094     // Delete FastLock node also if this Lock node is unique user
2095     // (a loop peeling may clone a Lock node).
2096     Node* flock = alock->as_Lock()->fastlock_node();
2097     if (flock->outcnt() == 1) {
2098       assert(flock->unique_out() == alock, "sanity");
2099       _igvn.replace_node(flock, top());
2100     }
2101   }
2102 
2103   // Seach for MemBarReleaseLock node and delete it also.
2104   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
2105       ctrl->in(0)->is_MemBar()) {
2106     MemBarNode* membar = ctrl->in(0)->as_MemBar();
2107     assert(membar->Opcode() == Op_MemBarReleaseLock &&
2108            mem->is_Proj() && membar == mem->in(0), "");
2109     _igvn.replace_node(fallthroughproj, ctrl);
2110     _igvn.replace_node(memproj_fallthrough, mem);
2111     fallthroughproj = ctrl;
2112     memproj_fallthrough = mem;
2113     ctrl = membar->in(TypeFunc::Control);
2114     mem  = membar->in(TypeFunc::Memory);
2115   }
2116 
2117   _igvn.replace_node(fallthroughproj, ctrl);
2118   _igvn.replace_node(memproj_fallthrough, mem);
2119   return true;
2120 }
2121 
2122 
2123 //------------------------------expand_lock_node----------------------
2124 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2125 
2126   Node* ctrl = lock->in(TypeFunc::Control);
2127   Node* mem = lock->in(TypeFunc::Memory);
2128   Node* obj = lock->obj_node();
2129   Node* box = lock->box_node();
2130   Node* flock = lock->fastlock_node();
2131 
2132   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2133 
2134   // Make the merge point
2135   Node *region;
2136   Node *mem_phi;
2137   Node *slow_path;
2138 
2139   if (UseOptoBiasInlining) {
2140     /*
2141      *  See the full description in MacroAssembler::biased_locking_enter().
2142      *
2143      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2144      *    // The object is biased.
2145      *    proto_node = klass->prototype_header;
2146      *    o_node = thread | proto_node;
2147      *    x_node = o_node ^ mark_word;
2148      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2149      *      // Done.
2150      *    } else {
2151      *      if( (x_node & biased_lock_mask) != 0 ) {
2152      *        // The klass's prototype header is no longer biased.
2153      *        cas(&mark_word, mark_word, proto_node)
2154      *        goto cas_lock;
2155      *      } else {
2156      *        // The klass's prototype header is still biased.
2157      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2158      *          old = mark_word;
2159      *          new = o_node;
2160      *        } else {
2161      *          // Different thread or anonymous biased.
2162      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2163      *          new = thread | old;
2164      *        }
2165      *        // Try to rebias.
2166      *        if( cas(&mark_word, old, new) == 0 ) {
2167      *          // Done.
2168      *        } else {
2169      *          goto slow_path; // Failed.
2170      *        }
2171      *      }
2172      *    }
2173      *  } else {
2174      *    // The object is not biased.
2175      *    cas_lock:
2176      *    if( FastLock(obj) == 0 ) {
2177      *      // Done.
2178      *    } else {
2179      *      slow_path:
2180      *      OptoRuntime::complete_monitor_locking_Java(obj);
2181      *    }
2182      *  }
2183      */
2184 
2185     region  = new RegionNode(5);
2186     // create a Phi for the memory state
2187     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2188 
2189     Node* fast_lock_region  = new RegionNode(3);
2190     Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2191 
2192     // First, check mark word for the biased lock pattern.
2193     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2194 
2195     // Get fast path - mark word has the biased lock pattern.
2196     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2197                          markOopDesc::biased_lock_mask_in_place,
2198                          markOopDesc::biased_lock_pattern, true);
2199     // fast_lock_region->in(1) is set to slow path.
2200     fast_lock_mem_phi->init_req(1, mem);
2201 
2202     // Now check that the lock is biased to the current thread and has
2203     // the same epoch and bias as Klass::_prototype_header.
2204 
2205     // Special-case a fresh allocation to avoid building nodes:
2206     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2207     if (klass_node == NULL) {
2208       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2209       klass_node = transform_later(LoadKlassNode::make(_igvn, NULL, mem, k_adr, _igvn.type(k_adr)->is_ptr()));
2210 #ifdef _LP64
2211       if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2212         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2213         klass_node->in(1)->init_req(0, ctrl);
2214       } else
2215 #endif
2216       klass_node->init_req(0, ctrl);
2217     }
2218     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2219 
2220     Node* thread = transform_later(new ThreadLocalNode());
2221     Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2222     Node* o_node = transform_later(new OrXNode(cast_thread, proto_node));
2223     Node* x_node = transform_later(new XorXNode(o_node, mark_node));
2224 
2225     // Get slow path - mark word does NOT match the value.
2226     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
2227                                       (~markOopDesc::age_mask_in_place), 0);
2228     // region->in(3) is set to fast path - the object is biased to the current thread.
2229     mem_phi->init_req(3, mem);
2230 
2231 
2232     // Mark word does NOT match the value (thread | Klass::_prototype_header).
2233 
2234 
2235     // First, check biased pattern.
2236     // Get fast path - _prototype_header has the same biased lock pattern.
2237     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2238                           markOopDesc::biased_lock_mask_in_place, 0, true);
2239 
2240     not_biased_ctrl = fast_lock_region->in(2); // Slow path
2241     // fast_lock_region->in(2) - the prototype header is no longer biased
2242     // and we have to revoke the bias on this object.
2243     // We are going to try to reset the mark of this object to the prototype
2244     // value and fall through to the CAS-based locking scheme.
2245     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2246     Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr,
2247                                           proto_node, mark_node);
2248     transform_later(cas);
2249     Node* proj = transform_later(new SCMemProjNode(cas));
2250     fast_lock_mem_phi->init_req(2, proj);
2251 
2252 
2253     // Second, check epoch bits.
2254     Node* rebiased_region  = new RegionNode(3);
2255     Node* old_phi = new PhiNode( rebiased_region, TypeX_X);
2256     Node* new_phi = new PhiNode( rebiased_region, TypeX_X);
2257 
2258     // Get slow path - mark word does NOT match epoch bits.
2259     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
2260                                       markOopDesc::epoch_mask_in_place, 0);
2261     // The epoch of the current bias is not valid, attempt to rebias the object
2262     // toward the current thread.
2263     rebiased_region->init_req(2, epoch_ctrl);
2264     old_phi->init_req(2, mark_node);
2265     new_phi->init_req(2, o_node);
2266 
2267     // rebiased_region->in(1) is set to fast path.
2268     // The epoch of the current bias is still valid but we know
2269     // nothing about the owner; it might be set or it might be clear.
2270     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
2271                              markOopDesc::age_mask_in_place |
2272                              markOopDesc::epoch_mask_in_place);
2273     Node* old = transform_later(new AndXNode(mark_node, cmask));
2274     cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2275     Node* new_mark = transform_later(new OrXNode(cast_thread, old));
2276     old_phi->init_req(1, old);
2277     new_phi->init_req(1, new_mark);
2278 
2279     transform_later(rebiased_region);
2280     transform_later(old_phi);
2281     transform_later(new_phi);
2282 
2283     // Try to acquire the bias of the object using an atomic operation.
2284     // If this fails we will go in to the runtime to revoke the object's bias.
2285     cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi);
2286     transform_later(cas);
2287     proj = transform_later(new SCMemProjNode(cas));
2288 
2289     // Get slow path - Failed to CAS.
2290     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2291     mem_phi->init_req(4, proj);
2292     // region->in(4) is set to fast path - the object is rebiased to the current thread.
2293 
2294     // Failed to CAS.
2295     slow_path  = new RegionNode(3);
2296     Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2297 
2298     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2299     slow_mem->init_req(1, proj);
2300 
2301     // Call CAS-based locking scheme (FastLock node).
2302 
2303     transform_later(fast_lock_region);
2304     transform_later(fast_lock_mem_phi);
2305 
2306     // Get slow path - FastLock failed to lock the object.
2307     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2308     mem_phi->init_req(2, fast_lock_mem_phi);
2309     // region->in(2) is set to fast path - the object is locked to the current thread.
2310 
2311     slow_path->init_req(2, ctrl); // Capture slow-control
2312     slow_mem->init_req(2, fast_lock_mem_phi);
2313 
2314     transform_later(slow_path);
2315     transform_later(slow_mem);
2316     // Reset lock's memory edge.
2317     lock->set_req(TypeFunc::Memory, slow_mem);
2318 
2319   } else {
2320     region  = new RegionNode(3);
2321     // create a Phi for the memory state
2322     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2323 
2324     // Optimize test; set region slot 2
2325     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2326     mem_phi->init_req(2, mem);
2327   }
2328 
2329   // Make slow path call
2330   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2331 
2332   extract_call_projections(call);
2333 
2334   // Slow path can only throw asynchronous exceptions, which are always
2335   // de-opted.  So the compiler thinks the slow-call can never throw an
2336   // exception.  If it DOES throw an exception we would need the debug
2337   // info removed first (since if it throws there is no monitor).
2338   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2339            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2340 
2341   // Capture slow path
2342   // disconnect fall-through projection from call and create a new one
2343   // hook up users of fall-through projection to region
2344   Node *slow_ctrl = _fallthroughproj->clone();
2345   transform_later(slow_ctrl);
2346   _igvn.hash_delete(_fallthroughproj);
2347   _fallthroughproj->disconnect_inputs(NULL, C);
2348   region->init_req(1, slow_ctrl);
2349   // region inputs are now complete
2350   transform_later(region);
2351   _igvn.replace_node(_fallthroughproj, region);
2352 
2353   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2354   mem_phi->init_req(1, memproj );
2355   transform_later(mem_phi);
2356   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2357 }
2358 
2359 //------------------------------expand_unlock_node----------------------
2360 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2361 
2362   Node* ctrl = unlock->in(TypeFunc::Control);
2363   Node* mem = unlock->in(TypeFunc::Memory);
2364   Node* obj = unlock->obj_node();
2365   Node* box = unlock->box_node();
2366 
2367   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2368 
2369   // No need for a null check on unlock
2370 
2371   // Make the merge point
2372   Node *region;
2373   Node *mem_phi;
2374 
2375   if (UseOptoBiasInlining) {
2376     // Check for biased locking unlock case, which is a no-op.
2377     // See the full description in MacroAssembler::biased_locking_exit().
2378     region  = new RegionNode(4);
2379     // create a Phi for the memory state
2380     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2381     mem_phi->init_req(3, mem);
2382 
2383     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2384     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2385                          markOopDesc::biased_lock_mask_in_place,
2386                          markOopDesc::biased_lock_pattern);
2387   } else {
2388     region  = new RegionNode(3);
2389     // create a Phi for the memory state
2390     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2391   }
2392 
2393   FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2394   funlock = transform_later( funlock )->as_FastUnlock();
2395   // Optimize test; set region slot 2
2396   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2397 
2398   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 );
2399 
2400   extract_call_projections(call);
2401 
2402   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2403            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2404 
2405   // No exceptions for unlocking
2406   // Capture slow path
2407   // disconnect fall-through projection from call and create a new one
2408   // hook up users of fall-through projection to region
2409   Node *slow_ctrl = _fallthroughproj->clone();
2410   transform_later(slow_ctrl);
2411   _igvn.hash_delete(_fallthroughproj);
2412   _fallthroughproj->disconnect_inputs(NULL, C);
2413   region->init_req(1, slow_ctrl);
2414   // region inputs are now complete
2415   transform_later(region);
2416   _igvn.replace_node(_fallthroughproj, region);
2417 
2418   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2419   mem_phi->init_req(1, memproj );
2420   mem_phi->init_req(2, mem);
2421   transform_later(mem_phi);
2422   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2423 }
2424 
2425 //---------------------------eliminate_macro_nodes----------------------
2426 // Eliminate scalar replaced allocations and associated locks.
2427 void PhaseMacroExpand::eliminate_macro_nodes() {
2428   if (C->macro_count() == 0)
2429     return;
2430 
2431   // First, attempt to eliminate locks
2432   int cnt = C->macro_count();
2433   for (int i=0; i < cnt; i++) {
2434     Node *n = C->macro_node(i);
2435     if (n->is_AbstractLock()) { // Lock and Unlock nodes
2436       // Before elimination mark all associated (same box and obj)
2437       // lock and unlock nodes.
2438       mark_eliminated_locking_nodes(n->as_AbstractLock());
2439     }
2440   }
2441   bool progress = true;
2442   while (progress) {
2443     progress = false;
2444     for (int i = C->macro_count(); i > 0; i--) {
2445       Node * n = C->macro_node(i-1);
2446       bool success = false;
2447       debug_only(int old_macro_count = C->macro_count(););
2448       if (n->is_AbstractLock()) {
2449         success = eliminate_locking_node(n->as_AbstractLock());
2450       }
2451       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2452       progress = progress || success;
2453     }
2454   }
2455   // Next, attempt to eliminate allocations
2456   _has_locks = false;
2457   progress = true;
2458   while (progress) {
2459     progress = false;
2460     for (int i = C->macro_count(); i > 0; i--) {
2461       Node * n = C->macro_node(i-1);
2462       bool success = false;
2463       debug_only(int old_macro_count = C->macro_count(););
2464       switch (n->class_id()) {
2465       case Node::Class_Allocate:
2466       case Node::Class_AllocateArray:
2467         success = eliminate_allocate_node(n->as_Allocate());
2468         break;
2469       case Node::Class_CallStaticJava:
2470         success = eliminate_boxing_node(n->as_CallStaticJava());
2471         break;
2472       case Node::Class_Lock:
2473       case Node::Class_Unlock:
2474         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2475         _has_locks = true;
2476         break;
2477       case Node::Class_ArrayCopy:
2478         break;
2479       default:
2480         assert(n->Opcode() == Op_LoopLimit ||
2481                n->Opcode() == Op_Opaque1   ||
2482                n->Opcode() == Op_Opaque2   ||
2483                n->Opcode() == Op_Opaque3, "unknown node type in macro list");
2484       }
2485       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2486       progress = progress || success;
2487     }
2488   }
2489 }
2490 
2491 //------------------------------expand_macro_nodes----------------------
2492 //  Returns true if a failure occurred.
2493 bool PhaseMacroExpand::expand_macro_nodes() {
2494   // Last attempt to eliminate macro nodes.
2495   eliminate_macro_nodes();
2496 
2497   // Make sure expansion will not cause node limit to be exceeded.
2498   // Worst case is a macro node gets expanded into about 50 nodes.
2499   // Allow 50% more for optimization.
2500   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2501     return true;
2502 
2503   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2504   bool progress = true;
2505   while (progress) {
2506     progress = false;
2507     for (int i = C->macro_count(); i > 0; i--) {
2508       Node * n = C->macro_node(i-1);
2509       bool success = false;
2510       debug_only(int old_macro_count = C->macro_count(););
2511       if (n->Opcode() == Op_LoopLimit) {
2512         // Remove it from macro list and put on IGVN worklist to optimize.
2513         C->remove_macro_node(n);
2514         _igvn._worklist.push(n);
2515         success = true;
2516       } else if (n->Opcode() == Op_CallStaticJava) {
2517         // Remove it from macro list and put on IGVN worklist to optimize.
2518         C->remove_macro_node(n);
2519         _igvn._worklist.push(n);
2520         success = true;
2521       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2522         _igvn.replace_node(n, n->in(1));
2523         success = true;
2524 #if INCLUDE_RTM_OPT
2525       } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2526         assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2527         assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2528         Node* cmp = n->unique_out();
2529 #ifdef ASSERT
2530         // Validate graph.
2531         assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2532         BoolNode* bol = cmp->unique_out()->as_Bool();
2533         assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2534                (bol->_test._test == BoolTest::ne), "");
2535         IfNode* ifn = bol->unique_out()->as_If();
2536         assert((ifn->outcnt() == 2) &&
2537                ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change), "");
2538 #endif
2539         Node* repl = n->in(1);
2540         if (!_has_locks) {
2541           // Remove RTM state check if there are no locks in the code.
2542           // Replace input to compare the same value.
2543           repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2544         }
2545         _igvn.replace_node(n, repl);
2546         success = true;
2547 #endif
2548       }
2549       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2550       progress = progress || success;
2551     }
2552   }
2553 
2554   // expand arraycopy "macro" nodes first
2555   // For ReduceBulkZeroing, we must first process all arraycopy nodes
2556   // before the allocate nodes are expanded.
2557   int macro_idx = C->macro_count() - 1;
2558   while (macro_idx >= 0) {
2559     Node * n = C->macro_node(macro_idx);
2560     assert(n->is_macro(), "only macro nodes expected here");
2561     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2562       // node is unreachable, so don't try to expand it
2563       C->remove_macro_node(n);
2564     } else if (n->is_ArrayCopy()){
2565       int macro_count = C->macro_count();
2566       expand_arraycopy_node(n->as_ArrayCopy());
2567       assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2568     }
2569     if (C->failing())  return true;
2570     macro_idx --;
2571   }
2572 
2573   // expand "macro" nodes
2574   // nodes are removed from the macro list as they are processed
2575   while (C->macro_count() > 0) {
2576     int macro_count = C->macro_count();
2577     Node * n = C->macro_node(macro_count-1);
2578     assert(n->is_macro(), "only macro nodes expected here");
2579     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2580       // node is unreachable, so don't try to expand it
2581       C->remove_macro_node(n);
2582       continue;
2583     }
2584     switch (n->class_id()) {
2585     case Node::Class_Allocate:
2586       expand_allocate(n->as_Allocate());
2587       break;
2588     case Node::Class_AllocateArray:
2589       expand_allocate_array(n->as_AllocateArray());
2590       break;
2591     case Node::Class_Lock:
2592       expand_lock_node(n->as_Lock());
2593       break;
2594     case Node::Class_Unlock:
2595       expand_unlock_node(n->as_Unlock());
2596       break;
2597     default:
2598       assert(false, "unknown node type in macro list");
2599     }
2600     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2601     if (C->failing())  return true;
2602   }
2603 
2604   _igvn.set_delay_transform(false);
2605   _igvn.optimize();
2606   if (C->failing())  return true;
2607   return false;
2608 }