rev 7652 : 8063137: Never-taken branches should be pruned when GWT LambdaForms are shared
Reviewed-by: ?
rev 7653 : [mq]: branch.freq.1

   1 /*
   2  * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "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 = NULL;
 262     for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
 263       Node* u = p2x->fast_out(i);
 264       if (u->Opcode() == Op_XorX) {
 265         xorx = u;
 266         break;
 267       }
 268     }
 269     assert(xorx != NULL, "missing G1 post barrier");
 270     Node* shift = xorx->unique_out();
 271     Node* cmpx = shift->unique_out();
 272     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
 273     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
 274     "missing region check in G1 post barrier");
 275     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 276 
 277     // Remove G1 pre barrier.
 278 
 279     // Search "if (marking != 0)" check and set it to "false".
 280     // There is no G1 pre barrier if previous stored value is NULL
 281     // (for example, after initialization).
 282     if (this_region->is_Region() && this_region->req() == 3) {
 283       int ind = 1;
 284       if (!this_region->in(ind)->is_IfFalse()) {
 285         ind = 2;
 286       }
 287       if (this_region->in(ind)->is_IfFalse()) {
 288         Node* bol = this_region->in(ind)->in(0)->in(1);
 289         assert(bol->is_Bool(), "");
 290         cmpx = bol->in(1);
 291         if (bol->as_Bool()->_test._test == BoolTest::ne &&
 292             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
 293             cmpx->in(1)->is_Load()) {
 294           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
 295           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
 296                                               PtrQueue::byte_offset_of_active());
 297           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
 298               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
 299               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
 300             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 301           }
 302         }
 303       }
 304     }
 305     // Now CastP2X can be removed since it is used only on dead path
 306     // which currently still alive until igvn optimize it.
 307     assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
 308     _igvn.replace_node(p2x, top());
 309   }
 310 }
 311 
 312 // Search for a memory operation for the specified memory slice.
 313 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
 314   Node *orig_mem = mem;
 315   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 316   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
 317   while (true) {
 318     if (mem == alloc_mem || mem == start_mem ) {
 319       return mem;  // hit one of our sentinels
 320     } else if (mem->is_MergeMem()) {
 321       mem = mem->as_MergeMem()->memory_at(alias_idx);
 322     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 323       Node *in = mem->in(0);
 324       // we can safely skip over safepoints, calls, locks and membars because we
 325       // already know that the object is safe to eliminate.
 326       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 327         return in;
 328       } else if (in->is_Call()) {
 329         CallNode *call = in->as_Call();
 330         if (!call->may_modify(tinst, phase)) {
 331           mem = call->in(TypeFunc::Memory);
 332         }
 333         mem = in->in(TypeFunc::Memory);
 334       } else if (in->is_MemBar()) {
 335         mem = in->in(TypeFunc::Memory);
 336       } else {
 337         assert(false, "unexpected projection");
 338       }
 339     } else if (mem->is_Store()) {
 340       const TypePtr* atype = mem->as_Store()->adr_type();
 341       int adr_idx = Compile::current()->get_alias_index(atype);
 342       if (adr_idx == alias_idx) {
 343         assert(atype->isa_oopptr(), "address type must be oopptr");
 344         int adr_offset = atype->offset();
 345         uint adr_iid = atype->is_oopptr()->instance_id();
 346         // Array elements references have the same alias_idx
 347         // but different offset and different instance_id.
 348         if (adr_offset == offset && adr_iid == alloc->_idx)
 349           return mem;
 350       } else {
 351         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 352       }
 353       mem = mem->in(MemNode::Memory);
 354     } else if (mem->is_ClearArray()) {
 355       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
 356         // Can not bypass initialization of the instance
 357         // we are looking.
 358         debug_only(intptr_t offset;)
 359         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
 360         InitializeNode* init = alloc->as_Allocate()->initialization();
 361         // We are looking for stored value, return Initialize node
 362         // or memory edge from Allocate node.
 363         if (init != NULL)
 364           return init;
 365         else
 366           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
 367       }
 368       // Otherwise skip it (the call updated 'mem' value).
 369     } else if (mem->Opcode() == Op_SCMemProj) {
 370       mem = mem->in(0);
 371       Node* adr = NULL;
 372       if (mem->is_LoadStore()) {
 373         adr = mem->in(MemNode::Address);
 374       } else {
 375         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
 376         adr = mem->in(3); // Destination array
 377       }
 378       const TypePtr* atype = adr->bottom_type()->is_ptr();
 379       int adr_idx = Compile::current()->get_alias_index(atype);
 380       if (adr_idx == alias_idx) {
 381         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 382         return NULL;
 383       }
 384       mem = mem->in(MemNode::Memory);
 385     } else {
 386       return mem;
 387     }
 388     assert(mem != orig_mem, "dead memory loop");
 389   }
 390 }
 391 
 392 //
 393 // Given a Memory Phi, compute a value Phi containing the values from stores
 394 // on the input paths.
 395 // Note: this function is recursive, its depth is limied by the "level" argument
 396 // Returns the computed Phi, or NULL if it cannot compute it.
 397 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) {
 398   assert(mem->is_Phi(), "sanity");
 399   int alias_idx = C->get_alias_index(adr_t);
 400   int offset = adr_t->offset();
 401   int instance_id = adr_t->instance_id();
 402 
 403   // Check if an appropriate value phi already exists.
 404   Node* region = mem->in(0);
 405   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 406     Node* phi = region->fast_out(k);
 407     if (phi->is_Phi() && phi != mem &&
 408         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
 409       return phi;
 410     }
 411   }
 412   // Check if an appropriate new value phi already exists.
 413   Node* new_phi = value_phis->find(mem->_idx);
 414   if (new_phi != NULL)
 415     return new_phi;
 416 
 417   if (level <= 0) {
 418     return NULL; // Give up: phi tree too deep
 419   }
 420   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 421   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 422 
 423   uint length = mem->req();
 424   GrowableArray <Node *> values(length, length, NULL, false);
 425 
 426   // create a new Phi for the value
 427   PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
 428   transform_later(phi);
 429   value_phis->push(phi, mem->_idx);
 430 
 431   for (uint j = 1; j < length; j++) {
 432     Node *in = mem->in(j);
 433     if (in == NULL || in->is_top()) {
 434       values.at_put(j, in);
 435     } else  {
 436       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
 437       if (val == start_mem || val == alloc_mem) {
 438         // hit a sentinel, return appropriate 0 value
 439         values.at_put(j, _igvn.zerocon(ft));
 440         continue;
 441       }
 442       if (val->is_Initialize()) {
 443         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 444       }
 445       if (val == NULL) {
 446         return NULL;  // can't find a value on this path
 447       }
 448       if (val == mem) {
 449         values.at_put(j, mem);
 450       } else if (val->is_Store()) {
 451         values.at_put(j, val->in(MemNode::ValueIn));
 452       } else if(val->is_Proj() && val->in(0) == alloc) {
 453         values.at_put(j, _igvn.zerocon(ft));
 454       } else if (val->is_Phi()) {
 455         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
 456         if (val == NULL) {
 457           return NULL;
 458         }
 459         values.at_put(j, val);
 460       } else if (val->Opcode() == Op_SCMemProj) {
 461         assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
 462         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 463         return NULL;
 464       } else {
 465 #ifdef ASSERT
 466         val->dump();
 467         assert(false, "unknown node on this path");
 468 #endif
 469         return NULL;  // unknown node on this path
 470       }
 471     }
 472   }
 473   // Set Phi's inputs
 474   for (uint j = 1; j < length; j++) {
 475     if (values.at(j) == mem) {
 476       phi->init_req(j, phi);
 477     } else {
 478       phi->init_req(j, values.at(j));
 479     }
 480   }
 481   return phi;
 482 }
 483 
 484 // Search the last value stored into the object's field.
 485 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
 486   assert(adr_t->is_known_instance_field(), "instance required");
 487   int instance_id = adr_t->instance_id();
 488   assert((uint)instance_id == alloc->_idx, "wrong allocation");
 489 
 490   int alias_idx = C->get_alias_index(adr_t);
 491   int offset = adr_t->offset();
 492   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 493   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
 494   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 495   Arena *a = Thread::current()->resource_area();
 496   VectorSet visited(a);
 497 
 498 
 499   bool done = sfpt_mem == alloc_mem;
 500   Node *mem = sfpt_mem;
 501   while (!done) {
 502     if (visited.test_set(mem->_idx)) {
 503       return NULL;  // found a loop, give up
 504     }
 505     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
 506     if (mem == start_mem || mem == alloc_mem) {
 507       done = true;  // hit a sentinel, return appropriate 0 value
 508     } else if (mem->is_Initialize()) {
 509       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 510       if (mem == NULL) {
 511         done = true; // Something go wrong.
 512       } else if (mem->is_Store()) {
 513         const TypePtr* atype = mem->as_Store()->adr_type();
 514         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 515         done = true;
 516       }
 517     } else if (mem->is_Store()) {
 518       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 519       assert(atype != NULL, "address type must be oopptr");
 520       assert(C->get_alias_index(atype) == alias_idx &&
 521              atype->is_known_instance_field() && atype->offset() == offset &&
 522              atype->instance_id() == instance_id, "store is correct memory slice");
 523       done = true;
 524     } else if (mem->is_Phi()) {
 525       // try to find a phi's unique input
 526       Node *unique_input = NULL;
 527       Node *top = C->top();
 528       for (uint i = 1; i < mem->req(); i++) {
 529         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
 530         if (n == NULL || n == top || n == mem) {
 531           continue;
 532         } else if (unique_input == NULL) {
 533           unique_input = n;
 534         } else if (unique_input != n) {
 535           unique_input = top;
 536           break;
 537         }
 538       }
 539       if (unique_input != NULL && unique_input != top) {
 540         mem = unique_input;
 541       } else {
 542         done = true;
 543       }
 544     } else {
 545       assert(false, "unexpected node");
 546     }
 547   }
 548   if (mem != NULL) {
 549     if (mem == start_mem || mem == alloc_mem) {
 550       // hit a sentinel, return appropriate 0 value
 551       return _igvn.zerocon(ft);
 552     } else if (mem->is_Store()) {
 553       return mem->in(MemNode::ValueIn);
 554     } else if (mem->is_Phi()) {
 555       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 556       Node_Stack value_phis(a, 8);
 557       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
 558       if (phi != NULL) {
 559         return phi;
 560       } else {
 561         // Kill all new Phis
 562         while(value_phis.is_nonempty()) {
 563           Node* n = value_phis.node();
 564           _igvn.replace_node(n, C->top());
 565           value_phis.pop();
 566         }
 567       }
 568     }
 569   }
 570   // Something go wrong.
 571   return NULL;
 572 }
 573 
 574 // Check the possibility of scalar replacement.
 575 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 576   //  Scan the uses of the allocation to check for anything that would
 577   //  prevent us from eliminating it.
 578   NOT_PRODUCT( const char* fail_eliminate = NULL; )
 579   DEBUG_ONLY( Node* disq_node = NULL; )
 580   bool  can_eliminate = true;
 581 
 582   Node* res = alloc->result_cast();
 583   const TypeOopPtr* res_type = NULL;
 584   if (res == NULL) {
 585     // All users were eliminated.
 586   } else if (!res->is_CheckCastPP()) {
 587     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 588     can_eliminate = false;
 589   } else {
 590     res_type = _igvn.type(res)->isa_oopptr();
 591     if (res_type == NULL) {
 592       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 593       can_eliminate = false;
 594     } else if (res_type->isa_aryptr()) {
 595       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 596       if (length < 0) {
 597         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 598         can_eliminate = false;
 599       }
 600     }
 601   }
 602 
 603   if (can_eliminate && res != NULL) {
 604     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
 605                                j < jmax && can_eliminate; j++) {
 606       Node* use = res->fast_out(j);
 607 
 608       if (use->is_AddP()) {
 609         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
 610         int offset = addp_type->offset();
 611 
 612         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 613           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
 614           can_eliminate = false;
 615           break;
 616         }
 617         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 618                                    k < kmax && can_eliminate; k++) {
 619           Node* n = use->fast_out(k);
 620           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
 621             DEBUG_ONLY(disq_node = n;)
 622             if (n->is_Load() || n->is_LoadStore()) {
 623               NOT_PRODUCT(fail_eliminate = "Field load";)
 624             } else {
 625               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
 626             }
 627             can_eliminate = false;
 628           }
 629         }
 630       } else if (use->is_SafePoint()) {
 631         SafePointNode* sfpt = use->as_SafePoint();
 632         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 633           // Object is passed as argument.
 634           DEBUG_ONLY(disq_node = use;)
 635           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 636           can_eliminate = false;
 637         }
 638         Node* sfptMem = sfpt->memory();
 639         if (sfptMem == NULL || sfptMem->is_top()) {
 640           DEBUG_ONLY(disq_node = use;)
 641           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
 642           can_eliminate = false;
 643         } else {
 644           safepoints.append_if_missing(sfpt);
 645         }
 646       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 647         if (use->is_Phi()) {
 648           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 649             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 650           } else {
 651             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 652           }
 653           DEBUG_ONLY(disq_node = use;)
 654         } else {
 655           if (use->Opcode() == Op_Return) {
 656             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 657           }else {
 658             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 659           }
 660           DEBUG_ONLY(disq_node = use;)
 661         }
 662         can_eliminate = false;
 663       }
 664     }
 665   }
 666 
 667 #ifndef PRODUCT
 668   if (PrintEliminateAllocations) {
 669     if (can_eliminate) {
 670       tty->print("Scalar ");
 671       if (res == NULL)
 672         alloc->dump();
 673       else
 674         res->dump();
 675     } else if (alloc->_is_scalar_replaceable) {
 676       tty->print("NotScalar (%s)", fail_eliminate);
 677       if (res == NULL)
 678         alloc->dump();
 679       else
 680         res->dump();
 681 #ifdef ASSERT
 682       if (disq_node != NULL) {
 683           tty->print("  >>>> ");
 684           disq_node->dump();
 685       }
 686 #endif /*ASSERT*/
 687     }
 688   }
 689 #endif
 690   return can_eliminate;
 691 }
 692 
 693 // Do scalar replacement.
 694 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 695   GrowableArray <SafePointNode *> safepoints_done;
 696 
 697   ciKlass* klass = NULL;
 698   ciInstanceKlass* iklass = NULL;
 699   int nfields = 0;
 700   int array_base;
 701   int element_size;
 702   BasicType basic_elem_type;
 703   ciType* elem_type;
 704 
 705   Node* res = alloc->result_cast();
 706   assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result");
 707   const TypeOopPtr* res_type = NULL;
 708   if (res != NULL) { // Could be NULL when there are no users
 709     res_type = _igvn.type(res)->isa_oopptr();
 710   }
 711 
 712   if (res != NULL) {
 713     klass = res_type->klass();
 714     if (res_type->isa_instptr()) {
 715       // find the fields of the class which will be needed for safepoint debug information
 716       assert(klass->is_instance_klass(), "must be an instance klass.");
 717       iklass = klass->as_instance_klass();
 718       nfields = iklass->nof_nonstatic_fields();
 719     } else {
 720       // find the array's elements which will be needed for safepoint debug information
 721       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 722       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
 723       elem_type = klass->as_array_klass()->element_type();
 724       basic_elem_type = elem_type->basic_type();
 725       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 726       element_size = type2aelembytes(basic_elem_type);
 727     }
 728   }
 729   //
 730   // Process the safepoint uses
 731   //
 732   while (safepoints.length() > 0) {
 733     SafePointNode* sfpt = safepoints.pop();
 734     Node* mem = sfpt->memory();
 735     assert(sfpt->jvms() != NULL, "missed JVMS");
 736     // Fields of scalar objs are referenced only at the end
 737     // of regular debuginfo at the last (youngest) JVMS.
 738     // Record relative start index.
 739     uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
 740     SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
 741 #ifdef ASSERT
 742                                                  alloc,
 743 #endif
 744                                                  first_ind, nfields);
 745     sobj->init_req(0, C->root());
 746     transform_later(sobj);
 747 
 748     // Scan object's fields adding an input to the safepoint for each field.
 749     for (int j = 0; j < nfields; j++) {
 750       intptr_t offset;
 751       ciField* field = NULL;
 752       if (iklass != NULL) {
 753         field = iklass->nonstatic_field_at(j);
 754         offset = field->offset();
 755         elem_type = field->type();
 756         basic_elem_type = field->layout_type();
 757       } else {
 758         offset = array_base + j * (intptr_t)element_size;
 759       }
 760 
 761       const Type *field_type;
 762       // The next code is taken from Parse::do_get_xxx().
 763       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
 764         if (!elem_type->is_loaded()) {
 765           field_type = TypeInstPtr::BOTTOM;
 766         } else if (field != NULL && field->is_constant() && field->is_static()) {
 767           // This can happen if the constant oop is non-perm.
 768           ciObject* con = field->constant_value().as_object();
 769           // Do not "join" in the previous type; it doesn't add value,
 770           // and may yield a vacuous result if the field is of interface type.
 771           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 772           assert(field_type != NULL, "field singleton type must be consistent");
 773         } else {
 774           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 775         }
 776         if (UseCompressedOops) {
 777           field_type = field_type->make_narrowoop();
 778           basic_elem_type = T_NARROWOOP;
 779         }
 780       } else {
 781         field_type = Type::get_const_basic_type(basic_elem_type);
 782       }
 783 
 784       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
 785 
 786       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
 787       if (field_val == NULL) {
 788         // We weren't able to find a value for this field,
 789         // give up on eliminating this allocation.
 790 
 791         // Remove any extra entries we added to the safepoint.
 792         uint last = sfpt->req() - 1;
 793         for (int k = 0;  k < j; k++) {
 794           sfpt->del_req(last--);
 795         }
 796         _igvn._worklist.push(sfpt);
 797         // rollback processed safepoints
 798         while (safepoints_done.length() > 0) {
 799           SafePointNode* sfpt_done = safepoints_done.pop();
 800           // remove any extra entries we added to the safepoint
 801           last = sfpt_done->req() - 1;
 802           for (int k = 0;  k < nfields; k++) {
 803             sfpt_done->del_req(last--);
 804           }
 805           JVMState *jvms = sfpt_done->jvms();
 806           jvms->set_endoff(sfpt_done->req());
 807           // Now make a pass over the debug information replacing any references
 808           // to SafePointScalarObjectNode with the allocated object.
 809           int start = jvms->debug_start();
 810           int end   = jvms->debug_end();
 811           for (int i = start; i < end; i++) {
 812             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 813               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 814               if (scobj->first_index(jvms) == sfpt_done->req() &&
 815                   scobj->n_fields() == (uint)nfields) {
 816                 assert(scobj->alloc() == alloc, "sanity");
 817                 sfpt_done->set_req(i, res);
 818               }
 819             }
 820           }
 821           _igvn._worklist.push(sfpt_done);
 822         }
 823 #ifndef PRODUCT
 824         if (PrintEliminateAllocations) {
 825           if (field != NULL) {
 826             tty->print("=== At SafePoint node %d can't find value of Field: ",
 827                        sfpt->_idx);
 828             field->print();
 829             int field_idx = C->get_alias_index(field_addr_type);
 830             tty->print(" (alias_idx=%d)", field_idx);
 831           } else { // Array's element
 832             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
 833                        sfpt->_idx, j);
 834           }
 835           tty->print(", which prevents elimination of: ");
 836           if (res == NULL)
 837             alloc->dump();
 838           else
 839             res->dump();
 840         }
 841 #endif
 842         return false;
 843       }
 844       if (UseCompressedOops && field_type->isa_narrowoop()) {
 845         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
 846         // to be able scalar replace the allocation.
 847         if (field_val->is_EncodeP()) {
 848           field_val = field_val->in(1);
 849         } else {
 850           field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
 851         }
 852       }
 853       sfpt->add_req(field_val);
 854     }
 855     JVMState *jvms = sfpt->jvms();
 856     jvms->set_endoff(sfpt->req());
 857     // Now make a pass over the debug information replacing any references
 858     // to the allocated object with "sobj"
 859     int start = jvms->debug_start();
 860     int end   = jvms->debug_end();
 861     sfpt->replace_edges_in_range(res, sobj, start, end);
 862     _igvn._worklist.push(sfpt);
 863     safepoints_done.append_if_missing(sfpt); // keep it for rollback
 864   }
 865   return true;
 866 }
 867 
 868 // Process users of eliminated allocation.
 869 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
 870   Node* res = alloc->result_cast();
 871   if (res != NULL) {
 872     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
 873       Node *use = res->last_out(j);
 874       uint oc1 = res->outcnt();
 875 
 876       if (use->is_AddP()) {
 877         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
 878           Node *n = use->last_out(k);
 879           uint oc2 = use->outcnt();
 880           if (n->is_Store()) {
 881 #ifdef ASSERT
 882             // Verify that there is no dependent MemBarVolatile nodes,
 883             // they should be removed during IGVN, see MemBarNode::Ideal().
 884             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
 885                                        p < pmax; p++) {
 886               Node* mb = n->fast_out(p);
 887               assert(mb->is_Initialize() || !mb->is_MemBar() ||
 888                      mb->req() <= MemBarNode::Precedent ||
 889                      mb->in(MemBarNode::Precedent) != n,
 890                      "MemBarVolatile should be eliminated for non-escaping object");
 891             }
 892 #endif
 893             _igvn.replace_node(n, n->in(MemNode::Memory));
 894           } else {
 895             eliminate_card_mark(n);
 896           }
 897           k -= (oc2 - use->outcnt());
 898         }
 899       } else {
 900         eliminate_card_mark(use);
 901       }
 902       j -= (oc1 - res->outcnt());
 903     }
 904     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
 905     _igvn.remove_dead_node(res);
 906   }
 907 
 908   //
 909   // Process other users of allocation's projections
 910   //
 911   if (_resproj != NULL && _resproj->outcnt() != 0) {
 912     // First disconnect stores captured by Initialize node.
 913     // If Initialize node is eliminated first in the following code,
 914     // it will kill such stores and DUIterator_Last will assert.
 915     for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax);  j < jmax; j++) {
 916       Node *use = _resproj->fast_out(j);
 917       if (use->is_AddP()) {
 918         // raw memory addresses used only by the initialization
 919         _igvn.replace_node(use, C->top());
 920         --j; --jmax;
 921       }
 922     }
 923     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
 924       Node *use = _resproj->last_out(j);
 925       uint oc1 = _resproj->outcnt();
 926       if (use->is_Initialize()) {
 927         // Eliminate Initialize node.
 928         InitializeNode *init = use->as_Initialize();
 929         assert(init->outcnt() <= 2, "only a control and memory projection expected");
 930         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
 931         if (ctrl_proj != NULL) {
 932            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
 933           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
 934         }
 935         Node *mem_proj = init->proj_out(TypeFunc::Memory);
 936         if (mem_proj != NULL) {
 937           Node *mem = init->in(TypeFunc::Memory);
 938 #ifdef ASSERT
 939           if (mem->is_MergeMem()) {
 940             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
 941           } else {
 942             assert(mem == _memproj_fallthrough, "allocation memory projection");
 943           }
 944 #endif
 945           _igvn.replace_node(mem_proj, mem);
 946         }
 947       } else  {
 948         assert(false, "only Initialize or AddP expected");
 949       }
 950       j -= (oc1 - _resproj->outcnt());
 951     }
 952   }
 953   if (_fallthroughcatchproj != NULL) {
 954     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
 955   }
 956   if (_memproj_fallthrough != NULL) {
 957     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
 958   }
 959   if (_memproj_catchall != NULL) {
 960     _igvn.replace_node(_memproj_catchall, C->top());
 961   }
 962   if (_ioproj_fallthrough != NULL) {
 963     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
 964   }
 965   if (_ioproj_catchall != NULL) {
 966     _igvn.replace_node(_ioproj_catchall, C->top());
 967   }
 968   if (_catchallcatchproj != NULL) {
 969     _igvn.replace_node(_catchallcatchproj, C->top());
 970   }
 971 }
 972 
 973 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
 974   // Don't do scalar replacement if the frame can be popped by JVMTI:
 975   // if reallocation fails during deoptimization we'll pop all
 976   // interpreter frames for this compiled frame and that won't play
 977   // nice with JVMTI popframe.
 978   if (!EliminateAllocations || JvmtiExport::can_pop_frame() || !alloc->_is_non_escaping) {
 979     return false;
 980   }
 981   Node* klass = alloc->in(AllocateNode::KlassNode);
 982   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
 983   Node* res = alloc->result_cast();
 984   // Eliminate boxing allocations which are not used
 985   // regardless scalar replacable status.
 986   bool boxing_alloc = C->eliminate_boxing() &&
 987                       tklass->klass()->is_instance_klass()  &&
 988                       tklass->klass()->as_instance_klass()->is_box_klass();
 989   if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
 990     return false;
 991   }
 992 
 993   extract_call_projections(alloc);
 994 
 995   GrowableArray <SafePointNode *> safepoints;
 996   if (!can_eliminate_allocation(alloc, safepoints)) {
 997     return false;
 998   }
 999 
1000   if (!alloc->_is_scalar_replaceable) {
1001     assert(res == NULL, "sanity");
1002     // We can only eliminate allocation if all debug info references
1003     // are already replaced with SafePointScalarObject because
1004     // we can't search for a fields value without instance_id.
1005     if (safepoints.length() > 0) {
1006       return false;
1007     }
1008   }
1009 
1010   if (!scalar_replacement(alloc, safepoints)) {
1011     return false;
1012   }
1013 
1014   CompileLog* log = C->log();
1015   if (log != NULL) {
1016     log->head("eliminate_allocation type='%d'",
1017               log->identify(tklass->klass()));
1018     JVMState* p = alloc->jvms();
1019     while (p != NULL) {
1020       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1021       p = p->caller();
1022     }
1023     log->tail("eliminate_allocation");
1024   }
1025 
1026   process_users_of_allocation(alloc);
1027 
1028 #ifndef PRODUCT
1029   if (PrintEliminateAllocations) {
1030     if (alloc->is_AllocateArray())
1031       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1032     else
1033       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1034   }
1035 #endif
1036 
1037   return true;
1038 }
1039 
1040 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1041   // EA should remove all uses of non-escaping boxing node.
1042   if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
1043     return false;
1044   }
1045 
1046   assert(boxing->result_cast() == NULL, "unexpected boxing node result");
1047 
1048   extract_call_projections(boxing);
1049 
1050   const TypeTuple* r = boxing->tf()->range();
1051   assert(r->cnt() > TypeFunc::Parms, "sanity");
1052   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1053   assert(t != NULL, "sanity");
1054 
1055   CompileLog* log = C->log();
1056   if (log != NULL) {
1057     log->head("eliminate_boxing type='%d'",
1058               log->identify(t->klass()));
1059     JVMState* p = boxing->jvms();
1060     while (p != NULL) {
1061       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1062       p = p->caller();
1063     }
1064     log->tail("eliminate_boxing");
1065   }
1066 
1067   process_users_of_allocation(boxing);
1068 
1069 #ifndef PRODUCT
1070   if (PrintEliminateAllocations) {
1071     tty->print("++++ Eliminated: %d ", boxing->_idx);
1072     boxing->method()->print_short_name(tty);
1073     tty->cr();
1074   }
1075 #endif
1076 
1077   return true;
1078 }
1079 
1080 //---------------------------set_eden_pointers-------------------------
1081 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1082   if (UseTLAB) {                // Private allocation: load from TLS
1083     Node* thread = transform_later(new ThreadLocalNode());
1084     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1085     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1086     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1087     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1088   } else {                      // Shared allocation: load from globals
1089     CollectedHeap* ch = Universe::heap();
1090     address top_adr = (address)ch->top_addr();
1091     address end_adr = (address)ch->end_addr();
1092     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1093     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1094   }
1095 }
1096 
1097 
1098 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1099   Node* adr = basic_plus_adr(base, offset);
1100   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1101   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1102   transform_later(value);
1103   return value;
1104 }
1105 
1106 
1107 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1108   Node* adr = basic_plus_adr(base, offset);
1109   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
1110   transform_later(mem);
1111   return mem;
1112 }
1113 
1114 //=============================================================================
1115 //
1116 //                              A L L O C A T I O N
1117 //
1118 // Allocation attempts to be fast in the case of frequent small objects.
1119 // It breaks down like this:
1120 //
1121 // 1) Size in doublewords is computed.  This is a constant for objects and
1122 // variable for most arrays.  Doubleword units are used to avoid size
1123 // overflow of huge doubleword arrays.  We need doublewords in the end for
1124 // rounding.
1125 //
1126 // 2) Size is checked for being 'too large'.  Too-large allocations will go
1127 // the slow path into the VM.  The slow path can throw any required
1128 // exceptions, and does all the special checks for very large arrays.  The
1129 // size test can constant-fold away for objects.  For objects with
1130 // finalizers it constant-folds the otherway: you always go slow with
1131 // finalizers.
1132 //
1133 // 3) If NOT using TLABs, this is the contended loop-back point.
1134 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
1135 //
1136 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
1137 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
1138 // "size*8" we always enter the VM, where "largish" is a constant picked small
1139 // enough that there's always space between the eden max and 4Gig (old space is
1140 // there so it's quite large) and large enough that the cost of entering the VM
1141 // is dwarfed by the cost to initialize the space.
1142 //
1143 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1144 // down.  If contended, repeat at step 3.  If using TLABs normal-store
1145 // adjusted heap top back down; there is no contention.
1146 //
1147 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
1148 // fields.
1149 //
1150 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1151 // oop flavor.
1152 //
1153 //=============================================================================
1154 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1155 // Allocations bigger than this always go the slow route.
1156 // This value must be small enough that allocation attempts that need to
1157 // trigger exceptions go the slow route.  Also, it must be small enough so
1158 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1159 //=============================================================================j//
1160 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1161 // The allocator will coalesce int->oop copies away.  See comment in
1162 // coalesce.cpp about how this works.  It depends critically on the exact
1163 // code shape produced here, so if you are changing this code shape
1164 // make sure the GC info for the heap-top is correct in and around the
1165 // slow-path call.
1166 //
1167 
1168 void PhaseMacroExpand::expand_allocate_common(
1169             AllocateNode* alloc, // allocation node to be expanded
1170             Node* length,  // array length for an array allocation
1171             const TypeFunc* slow_call_type, // Type of slow call
1172             address slow_call_address  // Address of slow call
1173     )
1174 {
1175 
1176   Node* ctrl = alloc->in(TypeFunc::Control);
1177   Node* mem  = alloc->in(TypeFunc::Memory);
1178   Node* i_o  = alloc->in(TypeFunc::I_O);
1179   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
1180   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
1181   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1182 
1183   assert(ctrl != NULL, "must have control");
1184   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1185   // they will not be used if "always_slow" is set
1186   enum { slow_result_path = 1, fast_result_path = 2 };
1187   Node *result_region;
1188   Node *result_phi_rawmem;
1189   Node *result_phi_rawoop;
1190   Node *result_phi_i_o;
1191 
1192   // The initial slow comparison is a size check, the comparison
1193   // we want to do is a BoolTest::gt
1194   bool always_slow = false;
1195   int tv = _igvn.find_int_con(initial_slow_test, -1);
1196   if (tv >= 0) {
1197     always_slow = (tv == 1);
1198     initial_slow_test = NULL;
1199   } else {
1200     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1201   }
1202 
1203   if (C->env()->dtrace_alloc_probes() ||
1204       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc())) {
1205     // Force slow-path allocation
1206     always_slow = true;
1207     initial_slow_test = NULL;
1208   }
1209 
1210 
1211   enum { too_big_or_final_path = 1, need_gc_path = 2 };
1212   Node *slow_region = NULL;
1213   Node *toobig_false = ctrl;
1214 
1215   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1216   // generate the initial test if necessary
1217   if (initial_slow_test != NULL ) {
1218     slow_region = new RegionNode(3);
1219 
1220     // Now make the initial failure test.  Usually a too-big test but
1221     // might be a TRUE for finalizers or a fancy class check for
1222     // newInstance0.
1223     IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1224     transform_later(toobig_iff);
1225     // Plug the failing-too-big test into the slow-path region
1226     Node *toobig_true = new IfTrueNode( toobig_iff );
1227     transform_later(toobig_true);
1228     slow_region    ->init_req( too_big_or_final_path, toobig_true );
1229     toobig_false = new IfFalseNode( toobig_iff );
1230     transform_later(toobig_false);
1231   } else {         // No initial test, just fall into next case
1232     toobig_false = ctrl;
1233     debug_only(slow_region = NodeSentinel);
1234   }
1235 
1236   Node *slow_mem = mem;  // save the current memory state for slow path
1237   // generate the fast allocation code unless we know that the initial test will always go slow
1238   if (!always_slow) {
1239     // Fast path modifies only raw memory.
1240     if (mem->is_MergeMem()) {
1241       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1242     }
1243 
1244     Node* eden_top_adr;
1245     Node* eden_end_adr;
1246 
1247     set_eden_pointers(eden_top_adr, eden_end_adr);
1248 
1249     // Load Eden::end.  Loop invariant and hoisted.
1250     //
1251     // Note: We set the control input on "eden_end" and "old_eden_top" when using
1252     //       a TLAB to work around a bug where these values were being moved across
1253     //       a safepoint.  These are not oops, so they cannot be include in the oop
1254     //       map, but they can be changed by a GC.   The proper way to fix this would
1255     //       be to set the raw memory state when generating a  SafepointNode.  However
1256     //       this will require extensive changes to the loop optimization in order to
1257     //       prevent a degradation of the optimization.
1258     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
1259     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1260 
1261     // allocate the Region and Phi nodes for the result
1262     result_region = new RegionNode(3);
1263     result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1264     result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1265     result_phi_i_o    = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1266 
1267     // We need a Region for the loop-back contended case.
1268     enum { fall_in_path = 1, contended_loopback_path = 2 };
1269     Node *contended_region;
1270     Node *contended_phi_rawmem;
1271     if (UseTLAB) {
1272       contended_region = toobig_false;
1273       contended_phi_rawmem = mem;
1274     } else {
1275       contended_region = new RegionNode(3);
1276       contended_phi_rawmem = new PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1277       // Now handle the passing-too-big test.  We fall into the contended
1278       // loop-back merge point.
1279       contended_region    ->init_req(fall_in_path, toobig_false);
1280       contended_phi_rawmem->init_req(fall_in_path, mem);
1281       transform_later(contended_region);
1282       transform_later(contended_phi_rawmem);
1283     }
1284 
1285     // Load(-locked) the heap top.
1286     // See note above concerning the control input when using a TLAB
1287     Node *old_eden_top = UseTLAB
1288       ? new LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered)
1289       : new LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr, MemNode::acquire);
1290 
1291     transform_later(old_eden_top);
1292     // Add to heap top to get a new heap top
1293     Node *new_eden_top = new AddPNode(top(), old_eden_top, size_in_bytes);
1294     transform_later(new_eden_top);
1295     // Check for needing a GC; compare against heap end
1296     Node *needgc_cmp = new CmpPNode(new_eden_top, eden_end);
1297     transform_later(needgc_cmp);
1298     Node *needgc_bol = new BoolNode(needgc_cmp, BoolTest::ge);
1299     transform_later(needgc_bol);
1300     IfNode *needgc_iff = new IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1301     transform_later(needgc_iff);
1302 
1303     // Plug the failing-heap-space-need-gc test into the slow-path region
1304     Node *needgc_true = new IfTrueNode(needgc_iff);
1305     transform_later(needgc_true);
1306     if (initial_slow_test) {
1307       slow_region->init_req(need_gc_path, needgc_true);
1308       // This completes all paths into the slow merge point
1309       transform_later(slow_region);
1310     } else {                      // No initial slow path needed!
1311       // Just fall from the need-GC path straight into the VM call.
1312       slow_region = needgc_true;
1313     }
1314     // No need for a GC.  Setup for the Store-Conditional
1315     Node *needgc_false = new IfFalseNode(needgc_iff);
1316     transform_later(needgc_false);
1317 
1318     // Grab regular I/O before optional prefetch may change it.
1319     // Slow-path does no I/O so just set it to the original I/O.
1320     result_phi_i_o->init_req(slow_result_path, i_o);
1321 
1322     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1323                               old_eden_top, new_eden_top, length);
1324 
1325     // Name successful fast-path variables
1326     Node* fast_oop = old_eden_top;
1327     Node* fast_oop_ctrl;
1328     Node* fast_oop_rawmem;
1329 
1330     // Store (-conditional) the modified eden top back down.
1331     // StorePConditional produces flags for a test PLUS a modified raw
1332     // memory state.
1333     if (UseTLAB) {
1334       Node* store_eden_top =
1335         new StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1336                               TypeRawPtr::BOTTOM, new_eden_top, MemNode::unordered);
1337       transform_later(store_eden_top);
1338       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1339       fast_oop_rawmem = store_eden_top;
1340     } else {
1341       Node* store_eden_top =
1342         new StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1343                                          new_eden_top, fast_oop/*old_eden_top*/);
1344       transform_later(store_eden_top);
1345       Node *contention_check = new BoolNode(store_eden_top, BoolTest::ne);
1346       transform_later(contention_check);
1347       store_eden_top = new SCMemProjNode(store_eden_top);
1348       transform_later(store_eden_top);
1349 
1350       // If not using TLABs, check to see if there was contention.
1351       IfNode *contention_iff = new IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1352       transform_later(contention_iff);
1353       Node *contention_true = new IfTrueNode(contention_iff);
1354       transform_later(contention_true);
1355       // If contention, loopback and try again.
1356       contended_region->init_req(contended_loopback_path, contention_true);
1357       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1358 
1359       // Fast-path succeeded with no contention!
1360       Node *contention_false = new IfFalseNode(contention_iff);
1361       transform_later(contention_false);
1362       fast_oop_ctrl = contention_false;
1363 
1364       // Bump total allocated bytes for this thread
1365       Node* thread = new ThreadLocalNode();
1366       transform_later(thread);
1367       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1368                                              in_bytes(JavaThread::allocated_bytes_offset()));
1369       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1370                                     0, TypeLong::LONG, T_LONG);
1371 #ifdef _LP64
1372       Node* alloc_size = size_in_bytes;
1373 #else
1374       Node* alloc_size = new ConvI2LNode(size_in_bytes);
1375       transform_later(alloc_size);
1376 #endif
1377       Node* new_alloc_bytes = new AddLNode(alloc_bytes, alloc_size);
1378       transform_later(new_alloc_bytes);
1379       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1380                                    0, new_alloc_bytes, T_LONG);
1381     }
1382 
1383     InitializeNode* init = alloc->initialization();
1384     fast_oop_rawmem = initialize_object(alloc,
1385                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1386                                         klass_node, length, size_in_bytes);
1387 
1388     // If initialization is performed by an array copy, any required
1389     // MemBarStoreStore was already added. If the object does not
1390     // escape no need for a MemBarStoreStore. Otherwise we need a
1391     // MemBarStoreStore so that stores that initialize this object
1392     // can't be reordered with a subsequent store that makes this
1393     // object accessible by other threads.
1394     if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
1395       if (init == NULL || init->req() < InitializeNode::RawStores) {
1396         // No InitializeNode or no stores captured by zeroing
1397         // elimination. Simply add the MemBarStoreStore after object
1398         // initialization.
1399         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1400         transform_later(mb);
1401 
1402         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1403         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1404         fast_oop_ctrl = new ProjNode(mb,TypeFunc::Control);
1405         transform_later(fast_oop_ctrl);
1406         fast_oop_rawmem = new ProjNode(mb,TypeFunc::Memory);
1407         transform_later(fast_oop_rawmem);
1408       } else {
1409         // Add the MemBarStoreStore after the InitializeNode so that
1410         // all stores performing the initialization that were moved
1411         // before the InitializeNode happen before the storestore
1412         // barrier.
1413 
1414         Node* init_ctrl = init->proj_out(TypeFunc::Control);
1415         Node* init_mem = init->proj_out(TypeFunc::Memory);
1416 
1417         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1418         transform_later(mb);
1419 
1420         Node* ctrl = new ProjNode(init,TypeFunc::Control);
1421         transform_later(ctrl);
1422         Node* mem = new ProjNode(init,TypeFunc::Memory);
1423         transform_later(mem);
1424 
1425         // The MemBarStoreStore depends on control and memory coming
1426         // from the InitializeNode
1427         mb->init_req(TypeFunc::Memory, mem);
1428         mb->init_req(TypeFunc::Control, ctrl);
1429 
1430         ctrl = new ProjNode(mb,TypeFunc::Control);
1431         transform_later(ctrl);
1432         mem = new ProjNode(mb,TypeFunc::Memory);
1433         transform_later(mem);
1434 
1435         // All nodes that depended on the InitializeNode for control
1436         // and memory must now depend on the MemBarNode that itself
1437         // depends on the InitializeNode
1438         _igvn.replace_node(init_ctrl, ctrl);
1439         _igvn.replace_node(init_mem, mem);
1440       }
1441     }
1442 
1443     if (C->env()->dtrace_extended_probes()) {
1444       // Slow-path call
1445       int size = TypeFunc::Parms + 2;
1446       CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1447                                             CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1448                                             "dtrace_object_alloc",
1449                                             TypeRawPtr::BOTTOM);
1450 
1451       // Get base of thread-local storage area
1452       Node* thread = new ThreadLocalNode();
1453       transform_later(thread);
1454 
1455       call->init_req(TypeFunc::Parms+0, thread);
1456       call->init_req(TypeFunc::Parms+1, fast_oop);
1457       call->init_req(TypeFunc::Control, fast_oop_ctrl);
1458       call->init_req(TypeFunc::I_O    , top()); // does no i/o
1459       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1460       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1461       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1462       transform_later(call);
1463       fast_oop_ctrl = new ProjNode(call,TypeFunc::Control);
1464       transform_later(fast_oop_ctrl);
1465       fast_oop_rawmem = new ProjNode(call,TypeFunc::Memory);
1466       transform_later(fast_oop_rawmem);
1467     }
1468 
1469     // Plug in the successful fast-path into the result merge point
1470     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
1471     result_phi_rawoop->init_req(fast_result_path, fast_oop);
1472     result_phi_i_o   ->init_req(fast_result_path, i_o);
1473     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1474   } else {
1475     slow_region = ctrl;
1476     result_phi_i_o = i_o; // Rename it to use in the following code.
1477   }
1478 
1479   // Generate slow-path call
1480   CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1481                                OptoRuntime::stub_name(slow_call_address),
1482                                alloc->jvms()->bci(),
1483                                TypePtr::BOTTOM);
1484   call->init_req( TypeFunc::Control, slow_region );
1485   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
1486   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1487   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1488   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1489 
1490   call->init_req(TypeFunc::Parms+0, klass_node);
1491   if (length != NULL) {
1492     call->init_req(TypeFunc::Parms+1, length);
1493   }
1494 
1495   // Copy debug information and adjust JVMState information, then replace
1496   // allocate node with the call
1497   copy_call_debug_info((CallNode *) alloc,  call);
1498   if (!always_slow) {
1499     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1500   } else {
1501     // Hook i_o projection to avoid its elimination during allocation
1502     // replacement (when only a slow call is generated).
1503     call->set_req(TypeFunc::I_O, result_phi_i_o);
1504   }
1505   _igvn.replace_node(alloc, call);
1506   transform_later(call);
1507 
1508   // Identify the output projections from the allocate node and
1509   // adjust any references to them.
1510   // The control and io projections look like:
1511   //
1512   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1513   //  Allocate                   Catch
1514   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1515   //
1516   //  We are interested in the CatchProj nodes.
1517   //
1518   extract_call_projections(call);
1519 
1520   // An allocate node has separate memory projections for the uses on
1521   // the control and i_o paths. Replace the control memory projection with
1522   // result_phi_rawmem (unless we are only generating a slow call when
1523   // both memory projections are combined)
1524   if (!always_slow && _memproj_fallthrough != NULL) {
1525     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1526       Node *use = _memproj_fallthrough->fast_out(i);
1527       _igvn.rehash_node_delayed(use);
1528       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1529       // back up iterator
1530       --i;
1531     }
1532   }
1533   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1534   // _memproj_catchall so we end up with a call that has only 1 memory projection.
1535   if (_memproj_catchall != NULL ) {
1536     if (_memproj_fallthrough == NULL) {
1537       _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory);
1538       transform_later(_memproj_fallthrough);
1539     }
1540     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1541       Node *use = _memproj_catchall->fast_out(i);
1542       _igvn.rehash_node_delayed(use);
1543       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1544       // back up iterator
1545       --i;
1546     }
1547     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1548     _igvn.remove_dead_node(_memproj_catchall);
1549   }
1550 
1551   // An allocate node has separate i_o projections for the uses on the control
1552   // and i_o paths. Always replace the control i_o projection with result i_o
1553   // otherwise incoming i_o become dead when only a slow call is generated
1554   // (it is different from memory projections where both projections are
1555   // combined in such case).
1556   if (_ioproj_fallthrough != NULL) {
1557     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1558       Node *use = _ioproj_fallthrough->fast_out(i);
1559       _igvn.rehash_node_delayed(use);
1560       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1561       // back up iterator
1562       --i;
1563     }
1564   }
1565   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1566   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1567   if (_ioproj_catchall != NULL ) {
1568     if (_ioproj_fallthrough == NULL) {
1569       _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O);
1570       transform_later(_ioproj_fallthrough);
1571     }
1572     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1573       Node *use = _ioproj_catchall->fast_out(i);
1574       _igvn.rehash_node_delayed(use);
1575       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1576       // back up iterator
1577       --i;
1578     }
1579     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1580     _igvn.remove_dead_node(_ioproj_catchall);
1581   }
1582 
1583   // if we generated only a slow call, we are done
1584   if (always_slow) {
1585     // Now we can unhook i_o.
1586     if (result_phi_i_o->outcnt() > 1) {
1587       call->set_req(TypeFunc::I_O, top());
1588     } else {
1589       assert(result_phi_i_o->unique_ctrl_out() == call, "");
1590       // Case of new array with negative size known during compilation.
1591       // AllocateArrayNode::Ideal() optimization disconnect unreachable
1592       // following code since call to runtime will throw exception.
1593       // As result there will be no users of i_o after the call.
1594       // Leave i_o attached to this call to avoid problems in preceding graph.
1595     }
1596     return;
1597   }
1598 
1599 
1600   if (_fallthroughcatchproj != NULL) {
1601     ctrl = _fallthroughcatchproj->clone();
1602     transform_later(ctrl);
1603     _igvn.replace_node(_fallthroughcatchproj, result_region);
1604   } else {
1605     ctrl = top();
1606   }
1607   Node *slow_result;
1608   if (_resproj == NULL) {
1609     // no uses of the allocation result
1610     slow_result = top();
1611   } else {
1612     slow_result = _resproj->clone();
1613     transform_later(slow_result);
1614     _igvn.replace_node(_resproj, result_phi_rawoop);
1615   }
1616 
1617   // Plug slow-path into result merge point
1618   result_region    ->init_req( slow_result_path, ctrl );
1619   result_phi_rawoop->init_req( slow_result_path, slow_result);
1620   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1621   transform_later(result_region);
1622   transform_later(result_phi_rawoop);
1623   transform_later(result_phi_rawmem);
1624   transform_later(result_phi_i_o);
1625   // This completes all paths into the result merge point
1626 }
1627 
1628 
1629 // Helper for PhaseMacroExpand::expand_allocate_common.
1630 // Initializes the newly-allocated storage.
1631 Node*
1632 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1633                                     Node* control, Node* rawmem, Node* object,
1634                                     Node* klass_node, Node* length,
1635                                     Node* size_in_bytes) {
1636   InitializeNode* init = alloc->initialization();
1637   // Store the klass & mark bits
1638   Node* mark_node = NULL;
1639   // For now only enable fast locking for non-array types
1640   if (UseBiasedLocking && (length == NULL)) {
1641     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1642   } else {
1643     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1644   }
1645   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1646 
1647   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1648   int header_size = alloc->minimum_header_size();  // conservatively small
1649 
1650   // Array length
1651   if (length != NULL) {         // Arrays need length field
1652     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1653     // conservatively small header size:
1654     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1655     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1656     if (k->is_array_klass())    // we know the exact header size in most cases:
1657       header_size = Klass::layout_helper_header_size(k->layout_helper());
1658   }
1659 
1660   // Clear the object body, if necessary.
1661   if (init == NULL) {
1662     // The init has somehow disappeared; be cautious and clear everything.
1663     //
1664     // This can happen if a node is allocated but an uncommon trap occurs
1665     // immediately.  In this case, the Initialize gets associated with the
1666     // trap, and may be placed in a different (outer) loop, if the Allocate
1667     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
1668     // there can be two Allocates to one Initialize.  The answer in all these
1669     // edge cases is safety first.  It is always safe to clear immediately
1670     // within an Allocate, and then (maybe or maybe not) clear some more later.
1671     if (!ZeroTLAB)
1672       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1673                                             header_size, size_in_bytes,
1674                                             &_igvn);
1675   } else {
1676     if (!init->is_complete()) {
1677       // Try to win by zeroing only what the init does not store.
1678       // We can also try to do some peephole optimizations,
1679       // such as combining some adjacent subword stores.
1680       rawmem = init->complete_stores(control, rawmem, object,
1681                                      header_size, size_in_bytes, &_igvn);
1682     }
1683     // We have no more use for this link, since the AllocateNode goes away:
1684     init->set_req(InitializeNode::RawAddress, top());
1685     // (If we keep the link, it just confuses the register allocator,
1686     // who thinks he sees a real use of the address by the membar.)
1687   }
1688 
1689   return rawmem;
1690 }
1691 
1692 // Generate prefetch instructions for next allocations.
1693 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1694                                         Node*& contended_phi_rawmem,
1695                                         Node* old_eden_top, Node* new_eden_top,
1696                                         Node* length) {
1697    enum { fall_in_path = 1, pf_path = 2 };
1698    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1699       // Generate prefetch allocation with watermark check.
1700       // As an allocation hits the watermark, we will prefetch starting
1701       // at a "distance" away from watermark.
1702 
1703       Node *pf_region = new RegionNode(3);
1704       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1705                                                 TypeRawPtr::BOTTOM );
1706       // I/O is used for Prefetch
1707       Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1708 
1709       Node *thread = new ThreadLocalNode();
1710       transform_later(thread);
1711 
1712       Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1713                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1714       transform_later(eden_pf_adr);
1715 
1716       Node *old_pf_wm = new LoadPNode(needgc_false,
1717                                    contended_phi_rawmem, eden_pf_adr,
1718                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1719                                    MemNode::unordered);
1720       transform_later(old_pf_wm);
1721 
1722       // check against new_eden_top
1723       Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1724       transform_later(need_pf_cmp);
1725       Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1726       transform_later(need_pf_bol);
1727       IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1728                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1729       transform_later(need_pf_iff);
1730 
1731       // true node, add prefetchdistance
1732       Node *need_pf_true = new IfTrueNode( need_pf_iff );
1733       transform_later(need_pf_true);
1734 
1735       Node *need_pf_false = new IfFalseNode( need_pf_iff );
1736       transform_later(need_pf_false);
1737 
1738       Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1739                                     _igvn.MakeConX(AllocatePrefetchDistance) );
1740       transform_later(new_pf_wmt );
1741       new_pf_wmt->set_req(0, need_pf_true);
1742 
1743       Node *store_new_wmt = new StorePNode(need_pf_true,
1744                                        contended_phi_rawmem, eden_pf_adr,
1745                                        TypeRawPtr::BOTTOM, new_pf_wmt,
1746                                        MemNode::unordered);
1747       transform_later(store_new_wmt);
1748 
1749       // adding prefetches
1750       pf_phi_abio->init_req( fall_in_path, i_o );
1751 
1752       Node *prefetch_adr;
1753       Node *prefetch;
1754       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1755       uint step_size = AllocatePrefetchStepSize;
1756       uint distance = 0;
1757 
1758       for ( uint i = 0; i < lines; i++ ) {
1759         prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1760                                             _igvn.MakeConX(distance) );
1761         transform_later(prefetch_adr);
1762         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1763         transform_later(prefetch);
1764         distance += step_size;
1765         i_o = prefetch;
1766       }
1767       pf_phi_abio->set_req( pf_path, i_o );
1768 
1769       pf_region->init_req( fall_in_path, need_pf_false );
1770       pf_region->init_req( pf_path, need_pf_true );
1771 
1772       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1773       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1774 
1775       transform_later(pf_region);
1776       transform_later(pf_phi_rawmem);
1777       transform_later(pf_phi_abio);
1778 
1779       needgc_false = pf_region;
1780       contended_phi_rawmem = pf_phi_rawmem;
1781       i_o = pf_phi_abio;
1782    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1783       // Insert a prefetch for each allocation.
1784       // This code is used for Sparc with BIS.
1785       Node *pf_region = new RegionNode(3);
1786       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1787                                              TypeRawPtr::BOTTOM );
1788       transform_later(pf_region);
1789 
1790       // Generate several prefetch instructions.
1791       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1792       uint step_size = AllocatePrefetchStepSize;
1793       uint distance = AllocatePrefetchDistance;
1794 
1795       // Next cache address.
1796       Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1797                                             _igvn.MakeConX(distance));
1798       transform_later(cache_adr);
1799       cache_adr = new CastP2XNode(needgc_false, cache_adr);
1800       transform_later(cache_adr);
1801       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1802       cache_adr = new AndXNode(cache_adr, mask);
1803       transform_later(cache_adr);
1804       cache_adr = new CastX2PNode(cache_adr);
1805       transform_later(cache_adr);
1806 
1807       // Prefetch
1808       Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1809       prefetch->set_req(0, needgc_false);
1810       transform_later(prefetch);
1811       contended_phi_rawmem = prefetch;
1812       Node *prefetch_adr;
1813       distance = step_size;
1814       for ( uint i = 1; i < lines; i++ ) {
1815         prefetch_adr = new AddPNode( cache_adr, cache_adr,
1816                                             _igvn.MakeConX(distance) );
1817         transform_later(prefetch_adr);
1818         prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1819         transform_later(prefetch);
1820         distance += step_size;
1821         contended_phi_rawmem = prefetch;
1822       }
1823    } else if( AllocatePrefetchStyle > 0 ) {
1824       // Insert a prefetch for each allocation only on the fast-path
1825       Node *prefetch_adr;
1826       Node *prefetch;
1827       // Generate several prefetch instructions.
1828       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1829       uint step_size = AllocatePrefetchStepSize;
1830       uint distance = AllocatePrefetchDistance;
1831       for ( uint i = 0; i < lines; i++ ) {
1832         prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1833                                             _igvn.MakeConX(distance) );
1834         transform_later(prefetch_adr);
1835         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1836         // Do not let it float too high, since if eden_top == eden_end,
1837         // both might be null.
1838         if( i == 0 ) { // Set control for first prefetch, next follows it
1839           prefetch->init_req(0, needgc_false);
1840         }
1841         transform_later(prefetch);
1842         distance += step_size;
1843         i_o = prefetch;
1844       }
1845    }
1846    return i_o;
1847 }
1848 
1849 
1850 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1851   expand_allocate_common(alloc, NULL,
1852                          OptoRuntime::new_instance_Type(),
1853                          OptoRuntime::new_instance_Java());
1854 }
1855 
1856 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1857   Node* length = alloc->in(AllocateNode::ALength);
1858   InitializeNode* init = alloc->initialization();
1859   Node* klass_node = alloc->in(AllocateNode::KlassNode);
1860   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1861   address slow_call_address;  // Address of slow call
1862   if (init != NULL && init->is_complete_with_arraycopy() &&
1863       k->is_type_array_klass()) {
1864     // Don't zero type array during slow allocation in VM since
1865     // it will be initialized later by arraycopy in compiled code.
1866     slow_call_address = OptoRuntime::new_array_nozero_Java();
1867   } else {
1868     slow_call_address = OptoRuntime::new_array_Java();
1869   }
1870   expand_allocate_common(alloc, length,
1871                          OptoRuntime::new_array_Type(),
1872                          slow_call_address);
1873 }
1874 
1875 //-------------------mark_eliminated_box----------------------------------
1876 //
1877 // During EA obj may point to several objects but after few ideal graph
1878 // transformations (CCP) it may point to only one non escaping object
1879 // (but still using phi), corresponding locks and unlocks will be marked
1880 // for elimination. Later obj could be replaced with a new node (new phi)
1881 // and which does not have escape information. And later after some graph
1882 // reshape other locks and unlocks (which were not marked for elimination
1883 // before) are connected to this new obj (phi) but they still will not be
1884 // marked for elimination since new obj has no escape information.
1885 // Mark all associated (same box and obj) lock and unlock nodes for
1886 // elimination if some of them marked already.
1887 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1888   if (oldbox->as_BoxLock()->is_eliminated())
1889     return; // This BoxLock node was processed already.
1890 
1891   // New implementation (EliminateNestedLocks) has separate BoxLock
1892   // node for each locked region so mark all associated locks/unlocks as
1893   // eliminated even if different objects are referenced in one locked region
1894   // (for example, OSR compilation of nested loop inside locked scope).
1895   if (EliminateNestedLocks ||
1896       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
1897     // Box is used only in one lock region. Mark this box as eliminated.
1898     _igvn.hash_delete(oldbox);
1899     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1900     _igvn.hash_insert(oldbox);
1901 
1902     for (uint i = 0; i < oldbox->outcnt(); i++) {
1903       Node* u = oldbox->raw_out(i);
1904       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1905         AbstractLockNode* alock = u->as_AbstractLock();
1906         // Check lock's box since box could be referenced by Lock's debug info.
1907         if (alock->box_node() == oldbox) {
1908           // Mark eliminated all related locks and unlocks.
1909           alock->set_non_esc_obj();
1910         }
1911       }
1912     }
1913     return;
1914   }
1915 
1916   // Create new "eliminated" BoxLock node and use it in monitor debug info
1917   // instead of oldbox for the same object.
1918   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1919 
1920   // Note: BoxLock node is marked eliminated only here and it is used
1921   // to indicate that all associated lock and unlock nodes are marked
1922   // for elimination.
1923   newbox->set_eliminated();
1924   transform_later(newbox);
1925 
1926   // Replace old box node with new box for all users of the same object.
1927   for (uint i = 0; i < oldbox->outcnt();) {
1928     bool next_edge = true;
1929 
1930     Node* u = oldbox->raw_out(i);
1931     if (u->is_AbstractLock()) {
1932       AbstractLockNode* alock = u->as_AbstractLock();
1933       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
1934         // Replace Box and mark eliminated all related locks and unlocks.
1935         alock->set_non_esc_obj();
1936         _igvn.rehash_node_delayed(alock);
1937         alock->set_box_node(newbox);
1938         next_edge = false;
1939       }
1940     }
1941     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
1942       FastLockNode* flock = u->as_FastLock();
1943       assert(flock->box_node() == oldbox, "sanity");
1944       _igvn.rehash_node_delayed(flock);
1945       flock->set_box_node(newbox);
1946       next_edge = false;
1947     }
1948 
1949     // Replace old box in monitor debug info.
1950     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1951       SafePointNode* sfn = u->as_SafePoint();
1952       JVMState* youngest_jvms = sfn->jvms();
1953       int max_depth = youngest_jvms->depth();
1954       for (int depth = 1; depth <= max_depth; depth++) {
1955         JVMState* jvms = youngest_jvms->of_depth(depth);
1956         int num_mon  = jvms->nof_monitors();
1957         // Loop over monitors
1958         for (int idx = 0; idx < num_mon; idx++) {
1959           Node* obj_node = sfn->monitor_obj(jvms, idx);
1960           Node* box_node = sfn->monitor_box(jvms, idx);
1961           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
1962             int j = jvms->monitor_box_offset(idx);
1963             _igvn.replace_input_of(u, j, newbox);
1964             next_edge = false;
1965           }
1966         }
1967       }
1968     }
1969     if (next_edge) i++;
1970   }
1971 }
1972 
1973 //-----------------------mark_eliminated_locking_nodes-----------------------
1974 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1975   if (EliminateNestedLocks) {
1976     if (alock->is_nested()) {
1977        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
1978        return;
1979     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
1980       // Only Lock node has JVMState needed here.
1981       if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
1982         // Mark eliminated related nested locks and unlocks.
1983         Node* obj = alock->obj_node();
1984         BoxLockNode* box_node = alock->box_node()->as_BoxLock();
1985         assert(!box_node->is_eliminated(), "should not be marked yet");
1986         // Note: BoxLock node is marked eliminated only here
1987         // and it is used to indicate that all associated lock
1988         // and unlock nodes are marked for elimination.
1989         box_node->set_eliminated(); // Box's hash is always NO_HASH here
1990         for (uint i = 0; i < box_node->outcnt(); i++) {
1991           Node* u = box_node->raw_out(i);
1992           if (u->is_AbstractLock()) {
1993             alock = u->as_AbstractLock();
1994             if (alock->box_node() == box_node) {
1995               // Verify that this Box is referenced only by related locks.
1996               assert(alock->obj_node()->eqv_uncast(obj), "");
1997               // Mark all related locks and unlocks.
1998               alock->set_nested();
1999             }
2000           }
2001         }
2002       }
2003       return;
2004     }
2005     // Process locks for non escaping object
2006     assert(alock->is_non_esc_obj(), "");
2007   } // EliminateNestedLocks
2008 
2009   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2010     // Look for all locks of this object and mark them and
2011     // corresponding BoxLock nodes as eliminated.
2012     Node* obj = alock->obj_node();
2013     for (uint j = 0; j < obj->outcnt(); j++) {
2014       Node* o = obj->raw_out(j);
2015       if (o->is_AbstractLock() &&
2016           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2017         alock = o->as_AbstractLock();
2018         Node* box = alock->box_node();
2019         // Replace old box node with new eliminated box for all users
2020         // of the same object and mark related locks as eliminated.
2021         mark_eliminated_box(box, obj);
2022       }
2023     }
2024   }
2025 }
2026 
2027 // we have determined that this lock/unlock can be eliminated, we simply
2028 // eliminate the node without expanding it.
2029 //
2030 // Note:  The membar's associated with the lock/unlock are currently not
2031 //        eliminated.  This should be investigated as a future enhancement.
2032 //
2033 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2034 
2035   if (!alock->is_eliminated()) {
2036     return false;
2037   }
2038 #ifdef ASSERT
2039   if (!alock->is_coarsened()) {
2040     // Check that new "eliminated" BoxLock node is created.
2041     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2042     assert(oldbox->is_eliminated(), "should be done already");
2043   }
2044 #endif
2045   CompileLog* log = C->log();
2046   if (log != NULL) {
2047     log->head("eliminate_lock lock='%d'",
2048               alock->is_Lock());
2049     JVMState* p = alock->jvms();
2050     while (p != NULL) {
2051       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
2052       p = p->caller();
2053     }
2054     log->tail("eliminate_lock");
2055   }
2056 
2057   #ifndef PRODUCT
2058   if (PrintEliminateLocks) {
2059     if (alock->is_Lock()) {
2060       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2061     } else {
2062       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2063     }
2064   }
2065   #endif
2066 
2067   Node* mem  = alock->in(TypeFunc::Memory);
2068   Node* ctrl = alock->in(TypeFunc::Control);
2069 
2070   extract_call_projections(alock);
2071   // There are 2 projections from the lock.  The lock node will
2072   // be deleted when its last use is subsumed below.
2073   assert(alock->outcnt() == 2 &&
2074          _fallthroughproj != NULL &&
2075          _memproj_fallthrough != NULL,
2076          "Unexpected projections from Lock/Unlock");
2077 
2078   Node* fallthroughproj = _fallthroughproj;
2079   Node* memproj_fallthrough = _memproj_fallthrough;
2080 
2081   // The memory projection from a lock/unlock is RawMem
2082   // The input to a Lock is merged memory, so extract its RawMem input
2083   // (unless the MergeMem has been optimized away.)
2084   if (alock->is_Lock()) {
2085     // Seach for MemBarAcquireLock node and delete it also.
2086     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2087     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2088     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2089     Node* memproj = membar->proj_out(TypeFunc::Memory);
2090     _igvn.replace_node(ctrlproj, fallthroughproj);
2091     _igvn.replace_node(memproj, memproj_fallthrough);
2092 
2093     // Delete FastLock node also if this Lock node is unique user
2094     // (a loop peeling may clone a Lock node).
2095     Node* flock = alock->as_Lock()->fastlock_node();
2096     if (flock->outcnt() == 1) {
2097       assert(flock->unique_out() == alock, "sanity");
2098       _igvn.replace_node(flock, top());
2099     }
2100   }
2101 
2102   // Seach for MemBarReleaseLock node and delete it also.
2103   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
2104       ctrl->in(0)->is_MemBar()) {
2105     MemBarNode* membar = ctrl->in(0)->as_MemBar();
2106     assert(membar->Opcode() == Op_MemBarReleaseLock &&
2107            mem->is_Proj() && membar == mem->in(0), "");
2108     _igvn.replace_node(fallthroughproj, ctrl);
2109     _igvn.replace_node(memproj_fallthrough, mem);
2110     fallthroughproj = ctrl;
2111     memproj_fallthrough = mem;
2112     ctrl = membar->in(TypeFunc::Control);
2113     mem  = membar->in(TypeFunc::Memory);
2114   }
2115 
2116   _igvn.replace_node(fallthroughproj, ctrl);
2117   _igvn.replace_node(memproj_fallthrough, mem);
2118   return true;
2119 }
2120 
2121 
2122 //------------------------------expand_lock_node----------------------
2123 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2124 
2125   Node* ctrl = lock->in(TypeFunc::Control);
2126   Node* mem = lock->in(TypeFunc::Memory);
2127   Node* obj = lock->obj_node();
2128   Node* box = lock->box_node();
2129   Node* flock = lock->fastlock_node();
2130 
2131   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2132 
2133   // Make the merge point
2134   Node *region;
2135   Node *mem_phi;
2136   Node *slow_path;
2137 
2138   if (UseOptoBiasInlining) {
2139     /*
2140      *  See the full description in MacroAssembler::biased_locking_enter().
2141      *
2142      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2143      *    // The object is biased.
2144      *    proto_node = klass->prototype_header;
2145      *    o_node = thread | proto_node;
2146      *    x_node = o_node ^ mark_word;
2147      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2148      *      // Done.
2149      *    } else {
2150      *      if( (x_node & biased_lock_mask) != 0 ) {
2151      *        // The klass's prototype header is no longer biased.
2152      *        cas(&mark_word, mark_word, proto_node)
2153      *        goto cas_lock;
2154      *      } else {
2155      *        // The klass's prototype header is still biased.
2156      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2157      *          old = mark_word;
2158      *          new = o_node;
2159      *        } else {
2160      *          // Different thread or anonymous biased.
2161      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2162      *          new = thread | old;
2163      *        }
2164      *        // Try to rebias.
2165      *        if( cas(&mark_word, old, new) == 0 ) {
2166      *          // Done.
2167      *        } else {
2168      *          goto slow_path; // Failed.
2169      *        }
2170      *      }
2171      *    }
2172      *  } else {
2173      *    // The object is not biased.
2174      *    cas_lock:
2175      *    if( FastLock(obj) == 0 ) {
2176      *      // Done.
2177      *    } else {
2178      *      slow_path:
2179      *      OptoRuntime::complete_monitor_locking_Java(obj);
2180      *    }
2181      *  }
2182      */
2183 
2184     region  = new RegionNode(5);
2185     // create a Phi for the memory state
2186     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2187 
2188     Node* fast_lock_region  = new RegionNode(3);
2189     Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2190 
2191     // First, check mark word for the biased lock pattern.
2192     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2193 
2194     // Get fast path - mark word has the biased lock pattern.
2195     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2196                          markOopDesc::biased_lock_mask_in_place,
2197                          markOopDesc::biased_lock_pattern, true);
2198     // fast_lock_region->in(1) is set to slow path.
2199     fast_lock_mem_phi->init_req(1, mem);
2200 
2201     // Now check that the lock is biased to the current thread and has
2202     // the same epoch and bias as Klass::_prototype_header.
2203 
2204     // Special-case a fresh allocation to avoid building nodes:
2205     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2206     if (klass_node == NULL) {
2207       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2208       klass_node = transform_later(LoadKlassNode::make(_igvn, NULL, mem, k_adr, _igvn.type(k_adr)->is_ptr()));
2209 #ifdef _LP64
2210       if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2211         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2212         klass_node->in(1)->init_req(0, ctrl);
2213       } else
2214 #endif
2215       klass_node->init_req(0, ctrl);
2216     }
2217     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2218 
2219     Node* thread = transform_later(new ThreadLocalNode());
2220     Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2221     Node* o_node = transform_later(new OrXNode(cast_thread, proto_node));
2222     Node* x_node = transform_later(new XorXNode(o_node, mark_node));
2223 
2224     // Get slow path - mark word does NOT match the value.
2225     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
2226                                       (~markOopDesc::age_mask_in_place), 0);
2227     // region->in(3) is set to fast path - the object is biased to the current thread.
2228     mem_phi->init_req(3, mem);
2229 
2230 
2231     // Mark word does NOT match the value (thread | Klass::_prototype_header).
2232 
2233 
2234     // First, check biased pattern.
2235     // Get fast path - _prototype_header has the same biased lock pattern.
2236     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2237                           markOopDesc::biased_lock_mask_in_place, 0, true);
2238 
2239     not_biased_ctrl = fast_lock_region->in(2); // Slow path
2240     // fast_lock_region->in(2) - the prototype header is no longer biased
2241     // and we have to revoke the bias on this object.
2242     // We are going to try to reset the mark of this object to the prototype
2243     // value and fall through to the CAS-based locking scheme.
2244     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2245     Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr,
2246                                           proto_node, mark_node);
2247     transform_later(cas);
2248     Node* proj = transform_later(new SCMemProjNode(cas));
2249     fast_lock_mem_phi->init_req(2, proj);
2250 
2251 
2252     // Second, check epoch bits.
2253     Node* rebiased_region  = new RegionNode(3);
2254     Node* old_phi = new PhiNode( rebiased_region, TypeX_X);
2255     Node* new_phi = new PhiNode( rebiased_region, TypeX_X);
2256 
2257     // Get slow path - mark word does NOT match epoch bits.
2258     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
2259                                       markOopDesc::epoch_mask_in_place, 0);
2260     // The epoch of the current bias is not valid, attempt to rebias the object
2261     // toward the current thread.
2262     rebiased_region->init_req(2, epoch_ctrl);
2263     old_phi->init_req(2, mark_node);
2264     new_phi->init_req(2, o_node);
2265 
2266     // rebiased_region->in(1) is set to fast path.
2267     // The epoch of the current bias is still valid but we know
2268     // nothing about the owner; it might be set or it might be clear.
2269     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
2270                              markOopDesc::age_mask_in_place |
2271                              markOopDesc::epoch_mask_in_place);
2272     Node* old = transform_later(new AndXNode(mark_node, cmask));
2273     cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2274     Node* new_mark = transform_later(new OrXNode(cast_thread, old));
2275     old_phi->init_req(1, old);
2276     new_phi->init_req(1, new_mark);
2277 
2278     transform_later(rebiased_region);
2279     transform_later(old_phi);
2280     transform_later(new_phi);
2281 
2282     // Try to acquire the bias of the object using an atomic operation.
2283     // If this fails we will go in to the runtime to revoke the object's bias.
2284     cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi);
2285     transform_later(cas);
2286     proj = transform_later(new SCMemProjNode(cas));
2287 
2288     // Get slow path - Failed to CAS.
2289     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2290     mem_phi->init_req(4, proj);
2291     // region->in(4) is set to fast path - the object is rebiased to the current thread.
2292 
2293     // Failed to CAS.
2294     slow_path  = new RegionNode(3);
2295     Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2296 
2297     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2298     slow_mem->init_req(1, proj);
2299 
2300     // Call CAS-based locking scheme (FastLock node).
2301 
2302     transform_later(fast_lock_region);
2303     transform_later(fast_lock_mem_phi);
2304 
2305     // Get slow path - FastLock failed to lock the object.
2306     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2307     mem_phi->init_req(2, fast_lock_mem_phi);
2308     // region->in(2) is set to fast path - the object is locked to the current thread.
2309 
2310     slow_path->init_req(2, ctrl); // Capture slow-control
2311     slow_mem->init_req(2, fast_lock_mem_phi);
2312 
2313     transform_later(slow_path);
2314     transform_later(slow_mem);
2315     // Reset lock's memory edge.
2316     lock->set_req(TypeFunc::Memory, slow_mem);
2317 
2318   } else {
2319     region  = new RegionNode(3);
2320     // create a Phi for the memory state
2321     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2322 
2323     // Optimize test; set region slot 2
2324     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2325     mem_phi->init_req(2, mem);
2326   }
2327 
2328   // Make slow path call
2329   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2330 
2331   extract_call_projections(call);
2332 
2333   // Slow path can only throw asynchronous exceptions, which are always
2334   // de-opted.  So the compiler thinks the slow-call can never throw an
2335   // exception.  If it DOES throw an exception we would need the debug
2336   // info removed first (since if it throws there is no monitor).
2337   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2338            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2339 
2340   // Capture slow path
2341   // disconnect fall-through projection from call and create a new one
2342   // hook up users of fall-through projection to region
2343   Node *slow_ctrl = _fallthroughproj->clone();
2344   transform_later(slow_ctrl);
2345   _igvn.hash_delete(_fallthroughproj);
2346   _fallthroughproj->disconnect_inputs(NULL, C);
2347   region->init_req(1, slow_ctrl);
2348   // region inputs are now complete
2349   transform_later(region);
2350   _igvn.replace_node(_fallthroughproj, region);
2351 
2352   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2353   mem_phi->init_req(1, memproj );
2354   transform_later(mem_phi);
2355   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2356 }
2357 
2358 //------------------------------expand_unlock_node----------------------
2359 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2360 
2361   Node* ctrl = unlock->in(TypeFunc::Control);
2362   Node* mem = unlock->in(TypeFunc::Memory);
2363   Node* obj = unlock->obj_node();
2364   Node* box = unlock->box_node();
2365 
2366   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2367 
2368   // No need for a null check on unlock
2369 
2370   // Make the merge point
2371   Node *region;
2372   Node *mem_phi;
2373 
2374   if (UseOptoBiasInlining) {
2375     // Check for biased locking unlock case, which is a no-op.
2376     // See the full description in MacroAssembler::biased_locking_exit().
2377     region  = new RegionNode(4);
2378     // create a Phi for the memory state
2379     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2380     mem_phi->init_req(3, mem);
2381 
2382     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2383     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2384                          markOopDesc::biased_lock_mask_in_place,
2385                          markOopDesc::biased_lock_pattern);
2386   } else {
2387     region  = new RegionNode(3);
2388     // create a Phi for the memory state
2389     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2390   }
2391 
2392   FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2393   funlock = transform_later( funlock )->as_FastUnlock();
2394   // Optimize test; set region slot 2
2395   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2396 
2397   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 );
2398 
2399   extract_call_projections(call);
2400 
2401   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2402            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2403 
2404   // No exceptions for unlocking
2405   // Capture slow path
2406   // disconnect fall-through projection from call and create a new one
2407   // hook up users of fall-through projection to region
2408   Node *slow_ctrl = _fallthroughproj->clone();
2409   transform_later(slow_ctrl);
2410   _igvn.hash_delete(_fallthroughproj);
2411   _fallthroughproj->disconnect_inputs(NULL, C);
2412   region->init_req(1, slow_ctrl);
2413   // region inputs are now complete
2414   transform_later(region);
2415   _igvn.replace_node(_fallthroughproj, region);
2416 
2417   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2418   mem_phi->init_req(1, memproj );
2419   mem_phi->init_req(2, mem);
2420   transform_later(mem_phi);
2421   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2422 }
2423 
2424 //---------------------------eliminate_macro_nodes----------------------
2425 // Eliminate scalar replaced allocations and associated locks.
2426 void PhaseMacroExpand::eliminate_macro_nodes() {
2427   if (C->macro_count() == 0)
2428     return;
2429 
2430   // First, attempt to eliminate locks
2431   int cnt = C->macro_count();
2432   for (int i=0; i < cnt; i++) {
2433     Node *n = C->macro_node(i);
2434     if (n->is_AbstractLock()) { // Lock and Unlock nodes
2435       // Before elimination mark all associated (same box and obj)
2436       // lock and unlock nodes.
2437       mark_eliminated_locking_nodes(n->as_AbstractLock());
2438     }
2439   }
2440   bool progress = true;
2441   while (progress) {
2442     progress = false;
2443     for (int i = C->macro_count(); i > 0; i--) {
2444       Node * n = C->macro_node(i-1);
2445       bool success = false;
2446       debug_only(int old_macro_count = C->macro_count(););
2447       if (n->is_AbstractLock()) {
2448         success = eliminate_locking_node(n->as_AbstractLock());
2449       }
2450       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2451       progress = progress || success;
2452     }
2453   }
2454   // Next, attempt to eliminate allocations
2455   _has_locks = false;
2456   progress = true;
2457   while (progress) {
2458     progress = false;
2459     for (int i = C->macro_count(); i > 0; i--) {
2460       Node * n = C->macro_node(i-1);
2461       bool success = false;
2462       debug_only(int old_macro_count = C->macro_count(););
2463       switch (n->class_id()) {
2464       case Node::Class_Allocate:
2465       case Node::Class_AllocateArray:
2466         success = eliminate_allocate_node(n->as_Allocate());
2467         break;
2468       case Node::Class_CallStaticJava:
2469         success = eliminate_boxing_node(n->as_CallStaticJava());
2470         break;
2471       case Node::Class_Lock:
2472       case Node::Class_Unlock:
2473         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2474         _has_locks = true;
2475         break;
2476       case Node::Class_ArrayCopy:
2477         break;
2478       default:
2479         assert(n->Opcode() == Op_LoopLimit ||
2480                n->Opcode() == Op_Opaque1   ||
2481                n->Opcode() == Op_Opaque2   ||
2482                n->Opcode() == Op_Opaque3, "unknown node type in macro list");
2483       }
2484       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2485       progress = progress || success;
2486     }
2487   }
2488 }
2489 
2490 //------------------------------expand_macro_nodes----------------------
2491 //  Returns true if a failure occurred.
2492 bool PhaseMacroExpand::expand_macro_nodes() {
2493   // Last attempt to eliminate macro nodes.
2494   eliminate_macro_nodes();
2495 
2496   // Make sure expansion will not cause node limit to be exceeded.
2497   // Worst case is a macro node gets expanded into about 50 nodes.
2498   // Allow 50% more for optimization.
2499   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2500     return true;
2501 
2502   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2503   bool progress = true;
2504   while (progress) {
2505     progress = false;
2506     for (int i = C->macro_count(); i > 0; i--) {
2507       Node * n = C->macro_node(i-1);
2508       bool success = false;
2509       debug_only(int old_macro_count = C->macro_count(););
2510       if (n->Opcode() == Op_LoopLimit) {
2511         // Remove it from macro list and put on IGVN worklist to optimize.
2512         C->remove_macro_node(n);
2513         _igvn._worklist.push(n);
2514         success = true;
2515       } else if (n->Opcode() == Op_CallStaticJava) {
2516         // Remove it from macro list and put on IGVN worklist to optimize.
2517         C->remove_macro_node(n);
2518         _igvn._worklist.push(n);
2519         success = true;
2520       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2521         _igvn.replace_node(n, n->in(1));
2522         success = true;
2523 #if INCLUDE_RTM_OPT
2524       } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2525         assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2526         assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2527         Node* cmp = n->unique_out();
2528 #ifdef ASSERT
2529         // Validate graph.
2530         assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2531         BoolNode* bol = cmp->unique_out()->as_Bool();
2532         assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2533                (bol->_test._test == BoolTest::ne), "");
2534         IfNode* ifn = bol->unique_out()->as_If();
2535         assert((ifn->outcnt() == 2) &&
2536                ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change), "");
2537 #endif
2538         Node* repl = n->in(1);
2539         if (!_has_locks) {
2540           // Remove RTM state check if there are no locks in the code.
2541           // Replace input to compare the same value.
2542           repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2543         }
2544         _igvn.replace_node(n, repl);
2545         success = true;
2546 #endif
2547       }
2548       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2549       progress = progress || success;
2550     }
2551   }
2552 
2553   // expand arraycopy "macro" nodes first
2554   // For ReduceBulkZeroing, we must first process all arraycopy nodes
2555   // before the allocate nodes are expanded.
2556   int macro_idx = C->macro_count() - 1;
2557   while (macro_idx >= 0) {
2558     Node * n = C->macro_node(macro_idx);
2559     assert(n->is_macro(), "only macro nodes expected here");
2560     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2561       // node is unreachable, so don't try to expand it
2562       C->remove_macro_node(n);
2563     } else if (n->is_ArrayCopy()){
2564       int macro_count = C->macro_count();
2565       expand_arraycopy_node(n->as_ArrayCopy());
2566       assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2567     }
2568     if (C->failing())  return true;
2569     macro_idx --;
2570   }
2571 
2572   // expand "macro" nodes
2573   // nodes are removed from the macro list as they are processed
2574   while (C->macro_count() > 0) {
2575     int macro_count = C->macro_count();
2576     Node * n = C->macro_node(macro_count-1);
2577     assert(n->is_macro(), "only macro nodes expected here");
2578     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2579       // node is unreachable, so don't try to expand it
2580       C->remove_macro_node(n);
2581       continue;
2582     }
2583     switch (n->class_id()) {
2584     case Node::Class_Allocate:
2585       expand_allocate(n->as_Allocate());
2586       break;
2587     case Node::Class_AllocateArray:
2588       expand_allocate_array(n->as_AllocateArray());
2589       break;
2590     case Node::Class_Lock:
2591       expand_lock_node(n->as_Lock());
2592       break;
2593     case Node::Class_Unlock:
2594       expand_unlock_node(n->as_Unlock());
2595       break;
2596     default:
2597       assert(false, "unknown node type in macro list");
2598     }
2599     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2600     if (C->failing())  return true;
2601   }
2602 
2603   _igvn.set_delay_transform(false);
2604   _igvn.optimize();
2605   if (C->failing())  return true;
2606   return false;
2607 }
--- EOF ---