1 /*
   2  * Copyright (c) 2005, 2013, 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   newcall->set_jvms(oldcall->jvms());
  98   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
  99     jvms->set_map(newcall);
 100     jvms->set_locoff(jvms->locoff()+jvms_adj);
 101     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
 102     jvms->set_monoff(jvms->monoff()+jvms_adj);
 103     jvms->set_scloff(jvms->scloff()+jvms_adj);
 104     jvms->set_endoff(jvms->endoff()+jvms_adj);
 105   }
 106 }
 107 
 108 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
 109   Node* cmp;
 110   if (mask != 0) {
 111     Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
 112     cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
 113   } else {
 114     cmp = word;
 115   }
 116   Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
 117   IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
 118   transform_later(iff);
 119 
 120   // Fast path taken.
 121   Node *fast_taken = transform_later(new IfFalseNode(iff));
 122 
 123   // Fast path not-taken, i.e. slow path
 124   Node *slow_taken = transform_later(new IfTrueNode(iff));
 125 
 126   if (return_fast_path) {
 127     region->init_req(edge, slow_taken); // Capture slow-control
 128     return fast_taken;
 129   } else {
 130     region->init_req(edge, fast_taken); // Capture fast-control
 131     return slow_taken;
 132   }
 133 }
 134 
 135 //--------------------copy_predefined_input_for_runtime_call--------------------
 136 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
 137   // Set fixed predefined input arguments
 138   call->init_req( TypeFunc::Control, ctrl );
 139   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
 140   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
 141   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
 142   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
 143 }
 144 
 145 //------------------------------make_slow_call---------------------------------
 146 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) {
 147 
 148   // Slow-path call
 149  CallNode *call = leaf_name
 150    ? (CallNode*)new CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
 151    : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
 152 
 153   // Slow path call has no side-effects, uses few values
 154   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
 155   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
 156   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
 157   copy_call_debug_info(oldcall, call);
 158   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
 159   _igvn.replace_node(oldcall, call);
 160   transform_later(call);
 161 
 162   return call;
 163 }
 164 
 165 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
 166   _fallthroughproj = NULL;
 167   _fallthroughcatchproj = NULL;
 168   _ioproj_fallthrough = NULL;
 169   _ioproj_catchall = NULL;
 170   _catchallcatchproj = NULL;
 171   _memproj_fallthrough = NULL;
 172   _memproj_catchall = NULL;
 173   _resproj = NULL;
 174   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
 175     ProjNode *pn = call->fast_out(i)->as_Proj();
 176     switch (pn->_con) {
 177       case TypeFunc::Control:
 178       {
 179         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 180         _fallthroughproj = pn;
 181         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 182         const Node *cn = pn->fast_out(j);
 183         if (cn->is_Catch()) {
 184           ProjNode *cpn = NULL;
 185           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 186             cpn = cn->fast_out(k)->as_Proj();
 187             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 188             if (cpn->_con == CatchProjNode::fall_through_index)
 189               _fallthroughcatchproj = cpn;
 190             else {
 191               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 192               _catchallcatchproj = cpn;
 193             }
 194           }
 195         }
 196         break;
 197       }
 198       case TypeFunc::I_O:
 199         if (pn->_is_io_use)
 200           _ioproj_catchall = pn;
 201         else
 202           _ioproj_fallthrough = pn;
 203         break;
 204       case TypeFunc::Memory:
 205         if (pn->_is_io_use)
 206           _memproj_catchall = pn;
 207         else
 208           _memproj_fallthrough = pn;
 209         break;
 210       case TypeFunc::Parms:
 211         _resproj = pn;
 212         break;
 213       default:
 214         assert(false, "unexpected projection from allocation node.");
 215     }
 216   }
 217 
 218 }
 219 
 220 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
 221 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
 222   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
 223   if (!UseG1GC) {
 224     // vanilla/CMS post barrier
 225     Node *shift = p2x->unique_out();
 226     Node *addp = shift->unique_out();
 227     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 228       Node *mem = addp->last_out(j);
 229       if (UseCondCardMark && mem->is_Load()) {
 230         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 231         // The load is checking if the card has been written so
 232         // replace it with zero to fold the test.
 233         _igvn.replace_node(mem, intcon(0));
 234         continue;
 235       }
 236       assert(mem->is_Store(), "store required");
 237       _igvn.replace_node(mem, mem->in(MemNode::Memory));
 238     }
 239   } else {
 240     // G1 pre/post barriers
 241     assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
 242     // It could be only one user, URShift node, in Object.clone() instrinsic
 243     // but the new allocation is passed to arraycopy stub and it could not
 244     // be scalar replaced. So we don't check the case.
 245 
 246     // An other case of only one user (Xor) is when the value check for NULL
 247     // in G1 post barrier is folded after CCP so the code which used URShift
 248     // is removed.
 249 
 250     // Take Region node before eliminating post barrier since it also
 251     // eliminates CastP2X node when it has only one user.
 252     Node* this_region = p2x->in(0);
 253     assert(this_region != NULL, "");
 254 
 255     // Remove G1 post barrier.
 256 
 257     // Search for CastP2X->Xor->URShift->Cmp path which
 258     // checks if the store done to a different from the value's region.
 259     // And replace Cmp with #0 (false) to collapse G1 post barrier.
 260     Node* xorx = NULL;
 261     for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
 262       Node* u = p2x->fast_out(i);
 263       if (u->Opcode() == Op_XorX) {
 264         xorx = u;
 265         break;
 266       }
 267     }
 268     assert(xorx != NULL, "missing G1 post barrier");
 269     Node* shift = xorx->unique_out();
 270     Node* cmpx = shift->unique_out();
 271     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
 272     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
 273     "missing region check in G1 post barrier");
 274     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 275 
 276     // Remove G1 pre barrier.
 277 
 278     // Search "if (marking != 0)" check and set it to "false".
 279     // There is no G1 pre barrier if previous stored value is NULL
 280     // (for example, after initialization).
 281     if (this_region->is_Region() && this_region->req() == 3) {
 282       int ind = 1;
 283       if (!this_region->in(ind)->is_IfFalse()) {
 284         ind = 2;
 285       }
 286       if (this_region->in(ind)->is_IfFalse()) {
 287         Node* bol = this_region->in(ind)->in(0)->in(1);
 288         assert(bol->is_Bool(), "");
 289         cmpx = bol->in(1);
 290         if (bol->as_Bool()->_test._test == BoolTest::ne &&
 291             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
 292             cmpx->in(1)->is_Load()) {
 293           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
 294           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
 295                                               PtrQueue::byte_offset_of_active());
 296           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
 297               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
 298               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
 299             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 300           }
 301         }
 302       }
 303     }
 304     // Now CastP2X can be removed since it is used only on dead path
 305     // which currently still alive until igvn optimize it.
 306     assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
 307     _igvn.replace_node(p2x, top());
 308   }
 309 }
 310 
 311 // Search for a memory operation for the specified memory slice.
 312 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
 313   Node *orig_mem = mem;
 314   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 315   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
 316   while (true) {
 317     if (mem == alloc_mem || mem == start_mem ) {
 318       return mem;  // hit one of our sentinels
 319     } else if (mem->is_MergeMem()) {
 320       mem = mem->as_MergeMem()->memory_at(alias_idx);
 321     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 322       Node *in = mem->in(0);
 323       // we can safely skip over safepoints, calls, locks and membars because we
 324       // already know that the object is safe to eliminate.
 325       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 326         return in;
 327       } else if (in->is_Call()) {
 328         CallNode *call = in->as_Call();
 329         if (!call->may_modify(tinst, phase)) {
 330           mem = call->in(TypeFunc::Memory);
 331         }
 332         mem = in->in(TypeFunc::Memory);
 333       } else if (in->is_MemBar()) {
 334         mem = in->in(TypeFunc::Memory);
 335       } else {
 336         assert(false, "unexpected projection");
 337       }
 338     } else if (mem->is_Store()) {
 339       const TypePtr* atype = mem->as_Store()->adr_type();
 340       int adr_idx = Compile::current()->get_alias_index(atype);
 341       if (adr_idx == alias_idx) {
 342         assert(atype->isa_oopptr(), "address type must be oopptr");
 343         int adr_offset = atype->offset();
 344         uint adr_iid = atype->is_oopptr()->instance_id();
 345         // Array elements references have the same alias_idx
 346         // but different offset and different instance_id.
 347         if (adr_offset == offset && adr_iid == alloc->_idx)
 348           return mem;
 349       } else {
 350         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 351       }
 352       mem = mem->in(MemNode::Memory);
 353     } else if (mem->is_ClearArray()) {
 354       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
 355         // Can not bypass initialization of the instance
 356         // we are looking.
 357         debug_only(intptr_t offset;)
 358         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
 359         InitializeNode* init = alloc->as_Allocate()->initialization();
 360         // We are looking for stored value, return Initialize node
 361         // or memory edge from Allocate node.
 362         if (init != NULL)
 363           return init;
 364         else
 365           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
 366       }
 367       // Otherwise skip it (the call updated 'mem' value).
 368     } else if (mem->Opcode() == Op_SCMemProj) {
 369       mem = mem->in(0);
 370       Node* adr = NULL;
 371       if (mem->is_LoadStore()) {
 372         adr = mem->in(MemNode::Address);
 373       } else {
 374         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
 375         adr = mem->in(3); // Destination array
 376       }
 377       const TypePtr* atype = adr->bottom_type()->is_ptr();
 378       int adr_idx = Compile::current()->get_alias_index(atype);
 379       if (adr_idx == alias_idx) {
 380         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 381         return NULL;
 382       }
 383       mem = mem->in(MemNode::Memory);
 384     } else {
 385       return mem;
 386     }
 387     assert(mem != orig_mem, "dead memory loop");
 388   }
 389 }
 390 
 391 //
 392 // Given a Memory Phi, compute a value Phi containing the values from stores
 393 // on the input paths.
 394 // Note: this function is recursive, its depth is limied by the "level" argument
 395 // Returns the computed Phi, or NULL if it cannot compute it.
 396 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) {
 397   assert(mem->is_Phi(), "sanity");
 398   int alias_idx = C->get_alias_index(adr_t);
 399   int offset = adr_t->offset();
 400   int instance_id = adr_t->instance_id();
 401 
 402   // Check if an appropriate value phi already exists.
 403   Node* region = mem->in(0);
 404   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 405     Node* phi = region->fast_out(k);
 406     if (phi->is_Phi() && phi != mem &&
 407         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
 408       return phi;
 409     }
 410   }
 411   // Check if an appropriate new value phi already exists.
 412   Node* new_phi = value_phis->find(mem->_idx);
 413   if (new_phi != NULL)
 414     return new_phi;
 415 
 416   if (level <= 0) {
 417     return NULL; // Give up: phi tree too deep
 418   }
 419   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 420   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 421 
 422   uint length = mem->req();
 423   GrowableArray <Node *> values(length, length, NULL, false);
 424 
 425   // create a new Phi for the value
 426   PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
 427   transform_later(phi);
 428   value_phis->push(phi, mem->_idx);
 429 
 430   for (uint j = 1; j < length; j++) {
 431     Node *in = mem->in(j);
 432     if (in == NULL || in->is_top()) {
 433       values.at_put(j, in);
 434     } else  {
 435       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
 436       if (val == start_mem || val == alloc_mem) {
 437         // hit a sentinel, return appropriate 0 value
 438         values.at_put(j, _igvn.zerocon(ft));
 439         continue;
 440       }
 441       if (val->is_Initialize()) {
 442         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 443       }
 444       if (val == NULL) {
 445         return NULL;  // can't find a value on this path
 446       }
 447       if (val == mem) {
 448         values.at_put(j, mem);
 449       } else if (val->is_Store()) {
 450         values.at_put(j, val->in(MemNode::ValueIn));
 451       } else if(val->is_Proj() && val->in(0) == alloc) {
 452         values.at_put(j, _igvn.zerocon(ft));
 453       } else if (val->is_Phi()) {
 454         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
 455         if (val == NULL) {
 456           return NULL;
 457         }
 458         values.at_put(j, val);
 459       } else if (val->Opcode() == Op_SCMemProj) {
 460         assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
 461         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
 462         return NULL;
 463       } else {
 464 #ifdef ASSERT
 465         val->dump();
 466         assert(false, "unknown node on this path");
 467 #endif
 468         return NULL;  // unknown node on this path
 469       }
 470     }
 471   }
 472   // Set Phi's inputs
 473   for (uint j = 1; j < length; j++) {
 474     if (values.at(j) == mem) {
 475       phi->init_req(j, phi);
 476     } else {
 477       phi->init_req(j, values.at(j));
 478     }
 479   }
 480   return phi;
 481 }
 482 
 483 // Search the last value stored into the object's field.
 484 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
 485   assert(adr_t->is_known_instance_field(), "instance required");
 486   int instance_id = adr_t->instance_id();
 487   assert((uint)instance_id == alloc->_idx, "wrong allocation");
 488 
 489   int alias_idx = C->get_alias_index(adr_t);
 490   int offset = adr_t->offset();
 491   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 492   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
 493   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 494   Arena *a = Thread::current()->resource_area();
 495   VectorSet visited(a);
 496 
 497 
 498   bool done = sfpt_mem == alloc_mem;
 499   Node *mem = sfpt_mem;
 500   while (!done) {
 501     if (visited.test_set(mem->_idx)) {
 502       return NULL;  // found a loop, give up
 503     }
 504     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
 505     if (mem == start_mem || mem == alloc_mem) {
 506       done = true;  // hit a sentinel, return appropriate 0 value
 507     } else if (mem->is_Initialize()) {
 508       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 509       if (mem == NULL) {
 510         done = true; // Something go wrong.
 511       } else if (mem->is_Store()) {
 512         const TypePtr* atype = mem->as_Store()->adr_type();
 513         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 514         done = true;
 515       }
 516     } else if (mem->is_Store()) {
 517       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 518       assert(atype != NULL, "address type must be oopptr");
 519       assert(C->get_alias_index(atype) == alias_idx &&
 520              atype->is_known_instance_field() && atype->offset() == offset &&
 521              atype->instance_id() == instance_id, "store is correct memory slice");
 522       done = true;
 523     } else if (mem->is_Phi()) {
 524       // try to find a phi's unique input
 525       Node *unique_input = NULL;
 526       Node *top = C->top();
 527       for (uint i = 1; i < mem->req(); i++) {
 528         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
 529         if (n == NULL || n == top || n == mem) {
 530           continue;
 531         } else if (unique_input == NULL) {
 532           unique_input = n;
 533         } else if (unique_input != n) {
 534           unique_input = top;
 535           break;
 536         }
 537       }
 538       if (unique_input != NULL && unique_input != top) {
 539         mem = unique_input;
 540       } else {
 541         done = true;
 542       }
 543     } else {
 544       assert(false, "unexpected node");
 545     }
 546   }
 547   if (mem != NULL) {
 548     if (mem == start_mem || mem == alloc_mem) {
 549       // hit a sentinel, return appropriate 0 value
 550       return _igvn.zerocon(ft);
 551     } else if (mem->is_Store()) {
 552       return mem->in(MemNode::ValueIn);
 553     } else if (mem->is_Phi()) {
 554       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 555       Node_Stack value_phis(a, 8);
 556       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
 557       if (phi != NULL) {
 558         return phi;
 559       } else {
 560         // Kill all new Phis
 561         while(value_phis.is_nonempty()) {
 562           Node* n = value_phis.node();
 563           _igvn.replace_node(n, C->top());
 564           value_phis.pop();
 565         }
 566       }
 567     }
 568   }
 569   // Something go wrong.
 570   return NULL;
 571 }
 572 
 573 // Check the possibility of scalar replacement.
 574 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 575   //  Scan the uses of the allocation to check for anything that would
 576   //  prevent us from eliminating it.
 577   NOT_PRODUCT( const char* fail_eliminate = NULL; )
 578   DEBUG_ONLY( Node* disq_node = NULL; )
 579   bool  can_eliminate = true;
 580 
 581   Node* res = alloc->result_cast();
 582   const TypeOopPtr* res_type = NULL;
 583   if (res == NULL) {
 584     // All users were eliminated.
 585   } else if (!res->is_CheckCastPP()) {
 586     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 587     can_eliminate = false;
 588   } else {
 589     res_type = _igvn.type(res)->isa_oopptr();
 590     if (res_type == NULL) {
 591       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 592       can_eliminate = false;
 593     } else if (res_type->isa_aryptr()) {
 594       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 595       if (length < 0) {
 596         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 597         can_eliminate = false;
 598       }
 599     }
 600   }
 601 
 602   if (can_eliminate && res != NULL) {
 603     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
 604                                j < jmax && can_eliminate; j++) {
 605       Node* use = res->fast_out(j);
 606 
 607       if (use->is_AddP()) {
 608         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
 609         int offset = addp_type->offset();
 610 
 611         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 612           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
 613           can_eliminate = false;
 614           break;
 615         }
 616         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 617                                    k < kmax && can_eliminate; k++) {
 618           Node* n = use->fast_out(k);
 619           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
 620             DEBUG_ONLY(disq_node = n;)
 621             if (n->is_Load() || n->is_LoadStore()) {
 622               NOT_PRODUCT(fail_eliminate = "Field load";)
 623             } else {
 624               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
 625             }
 626             can_eliminate = false;
 627           }
 628         }
 629       } else if (use->is_SafePoint()) {
 630         SafePointNode* sfpt = use->as_SafePoint();
 631         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 632           // Object is passed as argument.
 633           DEBUG_ONLY(disq_node = use;)
 634           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 635           can_eliminate = false;
 636         }
 637         Node* sfptMem = sfpt->memory();
 638         if (sfptMem == NULL || sfptMem->is_top()) {
 639           DEBUG_ONLY(disq_node = use;)
 640           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
 641           can_eliminate = false;
 642         } else {
 643           safepoints.append_if_missing(sfpt);
 644         }
 645       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 646         if (use->is_Phi()) {
 647           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 648             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 649           } else {
 650             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 651           }
 652           DEBUG_ONLY(disq_node = use;)
 653         } else {
 654           if (use->Opcode() == Op_Return) {
 655             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 656           }else {
 657             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 658           }
 659           DEBUG_ONLY(disq_node = use;)
 660         }
 661         can_eliminate = false;
 662       }
 663     }
 664   }
 665 
 666 #ifndef PRODUCT
 667   if (PrintEliminateAllocations) {
 668     if (can_eliminate) {
 669       tty->print("Scalar ");
 670       if (res == NULL)
 671         alloc->dump();
 672       else
 673         res->dump();
 674     } else if (alloc->_is_scalar_replaceable) {
 675       tty->print("NotScalar (%s)", fail_eliminate);
 676       if (res == NULL)
 677         alloc->dump();
 678       else
 679         res->dump();
 680 #ifdef ASSERT
 681       if (disq_node != NULL) {
 682           tty->print("  >>>> ");
 683           disq_node->dump();
 684       }
 685 #endif /*ASSERT*/
 686     }
 687   }
 688 #endif
 689   return can_eliminate;
 690 }
 691 
 692 // Do scalar replacement.
 693 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 694   GrowableArray <SafePointNode *> safepoints_done;
 695 
 696   ciKlass* klass = NULL;
 697   ciInstanceKlass* iklass = NULL;
 698   int nfields = 0;
 699   int array_base;
 700   int element_size;
 701   BasicType basic_elem_type;
 702   ciType* elem_type;
 703 
 704   Node* res = alloc->result_cast();
 705   const TypeOopPtr* res_type = NULL;
 706   if (res != NULL) { // Could be NULL when there are no users
 707     res_type = _igvn.type(res)->isa_oopptr();
 708   }
 709 
 710   if (res != NULL) {
 711     klass = res_type->klass();
 712     if (res_type->isa_instptr()) {
 713       // find the fields of the class which will be needed for safepoint debug information
 714       assert(klass->is_instance_klass(), "must be an instance klass.");
 715       iklass = klass->as_instance_klass();
 716       nfields = iklass->nof_nonstatic_fields();
 717     } else {
 718       // find the array's elements which will be needed for safepoint debug information
 719       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 720       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
 721       elem_type = klass->as_array_klass()->element_type();
 722       basic_elem_type = elem_type->basic_type();
 723       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 724       element_size = type2aelembytes(basic_elem_type);
 725     }
 726   }
 727   //
 728   // Process the safepoint uses
 729   //
 730   while (safepoints.length() > 0) {
 731     SafePointNode* sfpt = safepoints.pop();
 732     Node* mem = sfpt->memory();
 733     assert(sfpt->jvms() != NULL, "missed JVMS");
 734     // Fields of scalar objs are referenced only at the end
 735     // of regular debuginfo at the last (youngest) JVMS.
 736     // Record relative start index.
 737     uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
 738     SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
 739 #ifdef ASSERT
 740                                                  alloc,
 741 #endif
 742                                                  first_ind, nfields);
 743     sobj->init_req(0, C->root());
 744     transform_later(sobj);
 745 
 746     // Scan object's fields adding an input to the safepoint for each field.
 747     for (int j = 0; j < nfields; j++) {
 748       intptr_t offset;
 749       ciField* field = NULL;
 750       if (iklass != NULL) {
 751         field = iklass->nonstatic_field_at(j);
 752         offset = field->offset();
 753         elem_type = field->type();
 754         basic_elem_type = field->layout_type();
 755       } else {
 756         offset = array_base + j * (intptr_t)element_size;
 757       }
 758 
 759       const Type *field_type;
 760       // The next code is taken from Parse::do_get_xxx().
 761       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
 762         if (!elem_type->is_loaded()) {
 763           field_type = TypeInstPtr::BOTTOM;
 764         } else if (field != NULL && field->is_constant() && field->is_static()) {
 765           // This can happen if the constant oop is non-perm.
 766           ciObject* con = field->constant_value().as_object();
 767           // Do not "join" in the previous type; it doesn't add value,
 768           // and may yield a vacuous result if the field is of interface type.
 769           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 770           assert(field_type != NULL, "field singleton type must be consistent");
 771         } else {
 772           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 773         }
 774         if (UseCompressedOops) {
 775           field_type = field_type->make_narrowoop();
 776           basic_elem_type = T_NARROWOOP;
 777         }
 778       } else {
 779         field_type = Type::get_const_basic_type(basic_elem_type);
 780       }
 781 
 782       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
 783 
 784       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
 785       if (field_val == NULL) {
 786         // We weren't able to find a value for this field,
 787         // give up on eliminating this allocation.
 788 
 789         // Remove any extra entries we added to the safepoint.
 790         uint last = sfpt->req() - 1;
 791         for (int k = 0;  k < j; k++) {
 792           sfpt->del_req(last--);
 793         }
 794         // rollback processed safepoints
 795         while (safepoints_done.length() > 0) {
 796           SafePointNode* sfpt_done = safepoints_done.pop();
 797           // remove any extra entries we added to the safepoint
 798           last = sfpt_done->req() - 1;
 799           for (int k = 0;  k < nfields; k++) {
 800             sfpt_done->del_req(last--);
 801           }
 802           JVMState *jvms = sfpt_done->jvms();
 803           jvms->set_endoff(sfpt_done->req());
 804           // Now make a pass over the debug information replacing any references
 805           // to SafePointScalarObjectNode with the allocated object.
 806           int start = jvms->debug_start();
 807           int end   = jvms->debug_end();
 808           for (int i = start; i < end; i++) {
 809             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 810               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 811               if (scobj->first_index(jvms) == sfpt_done->req() &&
 812                   scobj->n_fields() == (uint)nfields) {
 813                 assert(scobj->alloc() == alloc, "sanity");
 814                 sfpt_done->set_req(i, res);
 815               }
 816             }
 817           }
 818         }
 819 #ifndef PRODUCT
 820         if (PrintEliminateAllocations) {
 821           if (field != NULL) {
 822             tty->print("=== At SafePoint node %d can't find value of Field: ",
 823                        sfpt->_idx);
 824             field->print();
 825             int field_idx = C->get_alias_index(field_addr_type);
 826             tty->print(" (alias_idx=%d)", field_idx);
 827           } else { // Array's element
 828             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
 829                        sfpt->_idx, j);
 830           }
 831           tty->print(", which prevents elimination of: ");
 832           if (res == NULL)
 833             alloc->dump();
 834           else
 835             res->dump();
 836         }
 837 #endif
 838         return false;
 839       }
 840       if (UseCompressedOops && field_type->isa_narrowoop()) {
 841         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
 842         // to be able scalar replace the allocation.
 843         if (field_val->is_EncodeP()) {
 844           field_val = field_val->in(1);
 845         } else {
 846           field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
 847         }
 848       }
 849       sfpt->add_req(field_val);
 850     }
 851     JVMState *jvms = sfpt->jvms();
 852     jvms->set_endoff(sfpt->req());
 853     // Now make a pass over the debug information replacing any references
 854     // to the allocated object with "sobj"
 855     int start = jvms->debug_start();
 856     int end   = jvms->debug_end();
 857     sfpt->replace_edges_in_range(res, sobj, start, end);
 858     _igvn._worklist.push(sfpt);
 859     safepoints_done.append_if_missing(sfpt); // keep it for rollback
 860   }
 861   return true;
 862 }
 863 
 864 // Process users of eliminated allocation.
 865 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
 866   Node* res = alloc->result_cast();
 867   if (res != NULL) {
 868     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
 869       Node *use = res->last_out(j);
 870       uint oc1 = res->outcnt();
 871 
 872       if (use->is_AddP()) {
 873         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
 874           Node *n = use->last_out(k);
 875           uint oc2 = use->outcnt();
 876           if (n->is_Store()) {
 877 #ifdef ASSERT
 878             // Verify that there is no dependent MemBarVolatile nodes,
 879             // they should be removed during IGVN, see MemBarNode::Ideal().
 880             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
 881                                        p < pmax; p++) {
 882               Node* mb = n->fast_out(p);
 883               assert(mb->is_Initialize() || !mb->is_MemBar() ||
 884                      mb->req() <= MemBarNode::Precedent ||
 885                      mb->in(MemBarNode::Precedent) != n,
 886                      "MemBarVolatile should be eliminated for non-escaping object");
 887             }
 888 #endif
 889             _igvn.replace_node(n, n->in(MemNode::Memory));
 890           } else {
 891             eliminate_card_mark(n);
 892           }
 893           k -= (oc2 - use->outcnt());
 894         }
 895       } else {
 896         eliminate_card_mark(use);
 897       }
 898       j -= (oc1 - res->outcnt());
 899     }
 900     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
 901     _igvn.remove_dead_node(res);
 902   }
 903 
 904   //
 905   // Process other users of allocation's projections
 906   //
 907   if (_resproj != NULL && _resproj->outcnt() != 0) {
 908     // First disconnect stores captured by Initialize node.
 909     // If Initialize node is eliminated first in the following code,
 910     // it will kill such stores and DUIterator_Last will assert.
 911     for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax);  j < jmax; j++) {
 912       Node *use = _resproj->fast_out(j);
 913       if (use->is_AddP()) {
 914         // raw memory addresses used only by the initialization
 915         _igvn.replace_node(use, C->top());
 916         --j; --jmax;
 917       }
 918     }
 919     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
 920       Node *use = _resproj->last_out(j);
 921       uint oc1 = _resproj->outcnt();
 922       if (use->is_Initialize()) {
 923         // Eliminate Initialize node.
 924         InitializeNode *init = use->as_Initialize();
 925         assert(init->outcnt() <= 2, "only a control and memory projection expected");
 926         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
 927         if (ctrl_proj != NULL) {
 928            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
 929           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
 930         }
 931         Node *mem_proj = init->proj_out(TypeFunc::Memory);
 932         if (mem_proj != NULL) {
 933           Node *mem = init->in(TypeFunc::Memory);
 934 #ifdef ASSERT
 935           if (mem->is_MergeMem()) {
 936             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
 937           } else {
 938             assert(mem == _memproj_fallthrough, "allocation memory projection");
 939           }
 940 #endif
 941           _igvn.replace_node(mem_proj, mem);
 942         }
 943       } else  {
 944         assert(false, "only Initialize or AddP expected");
 945       }
 946       j -= (oc1 - _resproj->outcnt());
 947     }
 948   }
 949   if (_fallthroughcatchproj != NULL) {
 950     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
 951   }
 952   if (_memproj_fallthrough != NULL) {
 953     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
 954   }
 955   if (_memproj_catchall != NULL) {
 956     _igvn.replace_node(_memproj_catchall, C->top());
 957   }
 958   if (_ioproj_fallthrough != NULL) {
 959     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
 960   }
 961   if (_ioproj_catchall != NULL) {
 962     _igvn.replace_node(_ioproj_catchall, C->top());
 963   }
 964   if (_catchallcatchproj != NULL) {
 965     _igvn.replace_node(_catchallcatchproj, C->top());
 966   }
 967 }
 968 
 969 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
 970   if (!EliminateAllocations || !alloc->_is_non_escaping) {
 971     return false;
 972   }
 973   Node* klass = alloc->in(AllocateNode::KlassNode);
 974   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
 975   Node* res = alloc->result_cast();
 976   // Eliminate boxing allocations which are not used
 977   // regardless scalar replacable status.
 978   bool boxing_alloc = C->eliminate_boxing() &&
 979                       tklass->klass()->is_instance_klass()  &&
 980                       tklass->klass()->as_instance_klass()->is_box_klass();
 981   if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
 982     return false;
 983   }
 984 
 985   extract_call_projections(alloc);
 986 
 987   GrowableArray <SafePointNode *> safepoints;
 988   if (!can_eliminate_allocation(alloc, safepoints)) {
 989     return false;
 990   }
 991 
 992   if (!alloc->_is_scalar_replaceable) {
 993     assert(res == NULL, "sanity");
 994     // We can only eliminate allocation if all debug info references
 995     // are already replaced with SafePointScalarObject because
 996     // we can't search for a fields value without instance_id.
 997     if (safepoints.length() > 0) {
 998       return false;
 999     }
1000   }
1001 
1002   if (!scalar_replacement(alloc, safepoints)) {
1003     return false;
1004   }
1005 
1006   CompileLog* log = C->log();
1007   if (log != NULL) {
1008     log->head("eliminate_allocation type='%d'",
1009               log->identify(tklass->klass()));
1010     JVMState* p = alloc->jvms();
1011     while (p != NULL) {
1012       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1013       p = p->caller();
1014     }
1015     log->tail("eliminate_allocation");
1016   }
1017 
1018   process_users_of_allocation(alloc);
1019 
1020 #ifndef PRODUCT
1021   if (PrintEliminateAllocations) {
1022     if (alloc->is_AllocateArray())
1023       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1024     else
1025       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1026   }
1027 #endif
1028 
1029   return true;
1030 }
1031 
1032 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1033   // EA should remove all uses of non-escaping boxing node.
1034   if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
1035     return false;
1036   }
1037 
1038   extract_call_projections(boxing);
1039 
1040   const TypeTuple* r = boxing->tf()->range();
1041   assert(r->cnt() > TypeFunc::Parms, "sanity");
1042   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1043   assert(t != NULL, "sanity");
1044 
1045   CompileLog* log = C->log();
1046   if (log != NULL) {
1047     log->head("eliminate_boxing type='%d'",
1048               log->identify(t->klass()));
1049     JVMState* p = boxing->jvms();
1050     while (p != NULL) {
1051       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1052       p = p->caller();
1053     }
1054     log->tail("eliminate_boxing");
1055   }
1056 
1057   process_users_of_allocation(boxing);
1058 
1059 #ifndef PRODUCT
1060   if (PrintEliminateAllocations) {
1061     tty->print("++++ Eliminated: %d ", boxing->_idx);
1062     boxing->method()->print_short_name(tty);
1063     tty->cr();
1064   }
1065 #endif
1066 
1067   return true;
1068 }
1069 
1070 //---------------------------set_eden_pointers-------------------------
1071 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1072   if (UseTLAB) {                // Private allocation: load from TLS
1073     Node* thread = transform_later(new ThreadLocalNode());
1074     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1075     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1076     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1077     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1078   } else {                      // Shared allocation: load from globals
1079     CollectedHeap* ch = Universe::heap();
1080     address top_adr = (address)ch->top_addr();
1081     address end_adr = (address)ch->end_addr();
1082     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1083     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1084   }
1085 }
1086 
1087 
1088 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1089   Node* adr = basic_plus_adr(base, offset);
1090   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1091   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1092   transform_later(value);
1093   return value;
1094 }
1095 
1096 
1097 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1098   Node* adr = basic_plus_adr(base, offset);
1099   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
1100   transform_later(mem);
1101   return mem;
1102 }
1103 
1104 //=============================================================================
1105 //
1106 //                              A L L O C A T I O N
1107 //
1108 // Allocation attempts to be fast in the case of frequent small objects.
1109 // It breaks down like this:
1110 //
1111 // 1) Size in doublewords is computed.  This is a constant for objects and
1112 // variable for most arrays.  Doubleword units are used to avoid size
1113 // overflow of huge doubleword arrays.  We need doublewords in the end for
1114 // rounding.
1115 //
1116 // 2) Size is checked for being 'too large'.  Too-large allocations will go
1117 // the slow path into the VM.  The slow path can throw any required
1118 // exceptions, and does all the special checks for very large arrays.  The
1119 // size test can constant-fold away for objects.  For objects with
1120 // finalizers it constant-folds the otherway: you always go slow with
1121 // finalizers.
1122 //
1123 // 3) If NOT using TLABs, this is the contended loop-back point.
1124 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
1125 //
1126 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
1127 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
1128 // "size*8" we always enter the VM, where "largish" is a constant picked small
1129 // enough that there's always space between the eden max and 4Gig (old space is
1130 // there so it's quite large) and large enough that the cost of entering the VM
1131 // is dwarfed by the cost to initialize the space.
1132 //
1133 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1134 // down.  If contended, repeat at step 3.  If using TLABs normal-store
1135 // adjusted heap top back down; there is no contention.
1136 //
1137 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
1138 // fields.
1139 //
1140 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1141 // oop flavor.
1142 //
1143 //=============================================================================
1144 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1145 // Allocations bigger than this always go the slow route.
1146 // This value must be small enough that allocation attempts that need to
1147 // trigger exceptions go the slow route.  Also, it must be small enough so
1148 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1149 //=============================================================================j//
1150 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1151 // The allocator will coalesce int->oop copies away.  See comment in
1152 // coalesce.cpp about how this works.  It depends critically on the exact
1153 // code shape produced here, so if you are changing this code shape
1154 // make sure the GC info for the heap-top is correct in and around the
1155 // slow-path call.
1156 //
1157 
1158 void PhaseMacroExpand::expand_allocate_common(
1159             AllocateNode* alloc, // allocation node to be expanded
1160             Node* length,  // array length for an array allocation
1161             const TypeFunc* slow_call_type, // Type of slow call
1162             address slow_call_address  // Address of slow call
1163     )
1164 {
1165 
1166   Node* ctrl = alloc->in(TypeFunc::Control);
1167   Node* mem  = alloc->in(TypeFunc::Memory);
1168   Node* i_o  = alloc->in(TypeFunc::I_O);
1169   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
1170   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
1171   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1172 
1173   assert(ctrl != NULL, "must have control");
1174   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1175   // they will not be used if "always_slow" is set
1176   enum { slow_result_path = 1, fast_result_path = 2 };
1177   Node *result_region;
1178   Node *result_phi_rawmem;
1179   Node *result_phi_rawoop;
1180   Node *result_phi_i_o;
1181 
1182   // The initial slow comparison is a size check, the comparison
1183   // we want to do is a BoolTest::gt
1184   bool always_slow = false;
1185   int tv = _igvn.find_int_con(initial_slow_test, -1);
1186   if (tv >= 0) {
1187     always_slow = (tv == 1);
1188     initial_slow_test = NULL;
1189   } else {
1190     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1191   }
1192 
1193   if (C->env()->dtrace_alloc_probes() ||
1194       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
1195                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
1196     // Force slow-path allocation
1197     always_slow = true;
1198     initial_slow_test = NULL;
1199   }
1200 
1201 
1202   enum { too_big_or_final_path = 1, need_gc_path = 2 };
1203   Node *slow_region = NULL;
1204   Node *toobig_false = ctrl;
1205 
1206   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1207   // generate the initial test if necessary
1208   if (initial_slow_test != NULL ) {
1209     slow_region = new RegionNode(3);
1210 
1211     // Now make the initial failure test.  Usually a too-big test but
1212     // might be a TRUE for finalizers or a fancy class check for
1213     // newInstance0.
1214     IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1215     transform_later(toobig_iff);
1216     // Plug the failing-too-big test into the slow-path region
1217     Node *toobig_true = new IfTrueNode( toobig_iff );
1218     transform_later(toobig_true);
1219     slow_region    ->init_req( too_big_or_final_path, toobig_true );
1220     toobig_false = new IfFalseNode( toobig_iff );
1221     transform_later(toobig_false);
1222   } else {         // No initial test, just fall into next case
1223     toobig_false = ctrl;
1224     debug_only(slow_region = NodeSentinel);
1225   }
1226 
1227   Node *slow_mem = mem;  // save the current memory state for slow path
1228   // generate the fast allocation code unless we know that the initial test will always go slow
1229   if (!always_slow) {
1230     // Fast path modifies only raw memory.
1231     if (mem->is_MergeMem()) {
1232       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1233     }
1234 
1235     Node* eden_top_adr;
1236     Node* eden_end_adr;
1237 
1238     set_eden_pointers(eden_top_adr, eden_end_adr);
1239 
1240     // Load Eden::end.  Loop invariant and hoisted.
1241     //
1242     // Note: We set the control input on "eden_end" and "old_eden_top" when using
1243     //       a TLAB to work around a bug where these values were being moved across
1244     //       a safepoint.  These are not oops, so they cannot be include in the oop
1245     //       map, but they can be changed by a GC.   The proper way to fix this would
1246     //       be to set the raw memory state when generating a  SafepointNode.  However
1247     //       this will require extensive changes to the loop optimization in order to
1248     //       prevent a degradation of the optimization.
1249     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
1250     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1251 
1252     // allocate the Region and Phi nodes for the result
1253     result_region = new RegionNode(3);
1254     result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1255     result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1256     result_phi_i_o    = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1257 
1258     // We need a Region for the loop-back contended case.
1259     enum { fall_in_path = 1, contended_loopback_path = 2 };
1260     Node *contended_region;
1261     Node *contended_phi_rawmem;
1262     if (UseTLAB) {
1263       contended_region = toobig_false;
1264       contended_phi_rawmem = mem;
1265     } else {
1266       contended_region = new RegionNode(3);
1267       contended_phi_rawmem = new PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1268       // Now handle the passing-too-big test.  We fall into the contended
1269       // loop-back merge point.
1270       contended_region    ->init_req(fall_in_path, toobig_false);
1271       contended_phi_rawmem->init_req(fall_in_path, mem);
1272       transform_later(contended_region);
1273       transform_later(contended_phi_rawmem);
1274     }
1275 
1276     // Load(-locked) the heap top.
1277     // See note above concerning the control input when using a TLAB
1278     Node *old_eden_top = UseTLAB
1279       ? new LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered)
1280       : new LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr, MemNode::acquire);
1281 
1282     transform_later(old_eden_top);
1283     // Add to heap top to get a new heap top
1284     Node *new_eden_top = new AddPNode(top(), old_eden_top, size_in_bytes);
1285     transform_later(new_eden_top);
1286     // Check for needing a GC; compare against heap end
1287     Node *needgc_cmp = new CmpPNode(new_eden_top, eden_end);
1288     transform_later(needgc_cmp);
1289     Node *needgc_bol = new BoolNode(needgc_cmp, BoolTest::ge);
1290     transform_later(needgc_bol);
1291     IfNode *needgc_iff = new IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1292     transform_later(needgc_iff);
1293 
1294     // Plug the failing-heap-space-need-gc test into the slow-path region
1295     Node *needgc_true = new IfTrueNode(needgc_iff);
1296     transform_later(needgc_true);
1297     if (initial_slow_test) {
1298       slow_region->init_req(need_gc_path, needgc_true);
1299       // This completes all paths into the slow merge point
1300       transform_later(slow_region);
1301     } else {                      // No initial slow path needed!
1302       // Just fall from the need-GC path straight into the VM call.
1303       slow_region = needgc_true;
1304     }
1305     // No need for a GC.  Setup for the Store-Conditional
1306     Node *needgc_false = new IfFalseNode(needgc_iff);
1307     transform_later(needgc_false);
1308 
1309     // Grab regular I/O before optional prefetch may change it.
1310     // Slow-path does no I/O so just set it to the original I/O.
1311     result_phi_i_o->init_req(slow_result_path, i_o);
1312 
1313     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1314                               old_eden_top, new_eden_top, length);
1315 
1316     // Name successful fast-path variables
1317     Node* fast_oop = old_eden_top;
1318     Node* fast_oop_ctrl;
1319     Node* fast_oop_rawmem;
1320 
1321     // Store (-conditional) the modified eden top back down.
1322     // StorePConditional produces flags for a test PLUS a modified raw
1323     // memory state.
1324     if (UseTLAB) {
1325       Node* store_eden_top =
1326         new StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1327                               TypeRawPtr::BOTTOM, new_eden_top, MemNode::unordered);
1328       transform_later(store_eden_top);
1329       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1330       fast_oop_rawmem = store_eden_top;
1331     } else {
1332       Node* store_eden_top =
1333         new StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1334                                          new_eden_top, fast_oop/*old_eden_top*/);
1335       transform_later(store_eden_top);
1336       Node *contention_check = new BoolNode(store_eden_top, BoolTest::ne);
1337       transform_later(contention_check);
1338       store_eden_top = new SCMemProjNode(store_eden_top);
1339       transform_later(store_eden_top);
1340 
1341       // If not using TLABs, check to see if there was contention.
1342       IfNode *contention_iff = new IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1343       transform_later(contention_iff);
1344       Node *contention_true = new IfTrueNode(contention_iff);
1345       transform_later(contention_true);
1346       // If contention, loopback and try again.
1347       contended_region->init_req(contended_loopback_path, contention_true);
1348       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1349 
1350       // Fast-path succeeded with no contention!
1351       Node *contention_false = new IfFalseNode(contention_iff);
1352       transform_later(contention_false);
1353       fast_oop_ctrl = contention_false;
1354 
1355       // Bump total allocated bytes for this thread
1356       Node* thread = new ThreadLocalNode();
1357       transform_later(thread);
1358       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1359                                              in_bytes(JavaThread::allocated_bytes_offset()));
1360       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1361                                     0, TypeLong::LONG, T_LONG);
1362 #ifdef _LP64
1363       Node* alloc_size = size_in_bytes;
1364 #else
1365       Node* alloc_size = new ConvI2LNode(size_in_bytes);
1366       transform_later(alloc_size);
1367 #endif
1368       Node* new_alloc_bytes = new AddLNode(alloc_bytes, alloc_size);
1369       transform_later(new_alloc_bytes);
1370       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1371                                    0, new_alloc_bytes, T_LONG);
1372     }
1373 
1374     InitializeNode* init = alloc->initialization();
1375     fast_oop_rawmem = initialize_object(alloc,
1376                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1377                                         klass_node, length, size_in_bytes);
1378 
1379     // If initialization is performed by an array copy, any required
1380     // MemBarStoreStore was already added. If the object does not
1381     // escape no need for a MemBarStoreStore. Otherwise we need a
1382     // MemBarStoreStore so that stores that initialize this object
1383     // can't be reordered with a subsequent store that makes this
1384     // object accessible by other threads.
1385     if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
1386       if (init == NULL || init->req() < InitializeNode::RawStores) {
1387         // No InitializeNode or no stores captured by zeroing
1388         // elimination. Simply add the MemBarStoreStore after object
1389         // initialization.
1390         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1391         transform_later(mb);
1392 
1393         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1394         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1395         fast_oop_ctrl = new ProjNode(mb,TypeFunc::Control);
1396         transform_later(fast_oop_ctrl);
1397         fast_oop_rawmem = new ProjNode(mb,TypeFunc::Memory);
1398         transform_later(fast_oop_rawmem);
1399       } else {
1400         // Add the MemBarStoreStore after the InitializeNode so that
1401         // all stores performing the initialization that were moved
1402         // before the InitializeNode happen before the storestore
1403         // barrier.
1404 
1405         Node* init_ctrl = init->proj_out(TypeFunc::Control);
1406         Node* init_mem = init->proj_out(TypeFunc::Memory);
1407 
1408         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1409         transform_later(mb);
1410 
1411         Node* ctrl = new ProjNode(init,TypeFunc::Control);
1412         transform_later(ctrl);
1413         Node* mem = new ProjNode(init,TypeFunc::Memory);
1414         transform_later(mem);
1415 
1416         // The MemBarStoreStore depends on control and memory coming
1417         // from the InitializeNode
1418         mb->init_req(TypeFunc::Memory, mem);
1419         mb->init_req(TypeFunc::Control, ctrl);
1420 
1421         ctrl = new ProjNode(mb,TypeFunc::Control);
1422         transform_later(ctrl);
1423         mem = new ProjNode(mb,TypeFunc::Memory);
1424         transform_later(mem);
1425 
1426         // All nodes that depended on the InitializeNode for control
1427         // and memory must now depend on the MemBarNode that itself
1428         // depends on the InitializeNode
1429         _igvn.replace_node(init_ctrl, ctrl);
1430         _igvn.replace_node(init_mem, mem);
1431       }
1432     }
1433 
1434     if (C->env()->dtrace_extended_probes()) {
1435       // Slow-path call
1436       int size = TypeFunc::Parms + 2;
1437       CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1438                                             CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1439                                             "dtrace_object_alloc",
1440                                             TypeRawPtr::BOTTOM);
1441 
1442       // Get base of thread-local storage area
1443       Node* thread = new ThreadLocalNode();
1444       transform_later(thread);
1445 
1446       call->init_req(TypeFunc::Parms+0, thread);
1447       call->init_req(TypeFunc::Parms+1, fast_oop);
1448       call->init_req(TypeFunc::Control, fast_oop_ctrl);
1449       call->init_req(TypeFunc::I_O    , top()); // does no i/o
1450       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1451       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1452       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1453       transform_later(call);
1454       fast_oop_ctrl = new ProjNode(call,TypeFunc::Control);
1455       transform_later(fast_oop_ctrl);
1456       fast_oop_rawmem = new ProjNode(call,TypeFunc::Memory);
1457       transform_later(fast_oop_rawmem);
1458     }
1459 
1460     // Plug in the successful fast-path into the result merge point
1461     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
1462     result_phi_rawoop->init_req(fast_result_path, fast_oop);
1463     result_phi_i_o   ->init_req(fast_result_path, i_o);
1464     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1465   } else {
1466     slow_region = ctrl;
1467     result_phi_i_o = i_o; // Rename it to use in the following code.
1468   }
1469 
1470   // Generate slow-path call
1471   CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1472                                OptoRuntime::stub_name(slow_call_address),
1473                                alloc->jvms()->bci(),
1474                                TypePtr::BOTTOM);
1475   call->init_req( TypeFunc::Control, slow_region );
1476   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
1477   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1478   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1479   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1480 
1481   call->init_req(TypeFunc::Parms+0, klass_node);
1482   if (length != NULL) {
1483     call->init_req(TypeFunc::Parms+1, length);
1484   }
1485 
1486   // Copy debug information and adjust JVMState information, then replace
1487   // allocate node with the call
1488   copy_call_debug_info((CallNode *) alloc,  call);
1489   if (!always_slow) {
1490     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1491   } else {
1492     // Hook i_o projection to avoid its elimination during allocation
1493     // replacement (when only a slow call is generated).
1494     call->set_req(TypeFunc::I_O, result_phi_i_o);
1495   }
1496   _igvn.replace_node(alloc, call);
1497   transform_later(call);
1498 
1499   // Identify the output projections from the allocate node and
1500   // adjust any references to them.
1501   // The control and io projections look like:
1502   //
1503   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1504   //  Allocate                   Catch
1505   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1506   //
1507   //  We are interested in the CatchProj nodes.
1508   //
1509   extract_call_projections(call);
1510 
1511   // An allocate node has separate memory projections for the uses on
1512   // the control and i_o paths. Replace the control memory projection with
1513   // result_phi_rawmem (unless we are only generating a slow call when
1514   // both memory projections are combined)
1515   if (!always_slow && _memproj_fallthrough != NULL) {
1516     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1517       Node *use = _memproj_fallthrough->fast_out(i);
1518       _igvn.rehash_node_delayed(use);
1519       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1520       // back up iterator
1521       --i;
1522     }
1523   }
1524   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1525   // _memproj_catchall so we end up with a call that has only 1 memory projection.
1526   if (_memproj_catchall != NULL ) {
1527     if (_memproj_fallthrough == NULL) {
1528       _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory);
1529       transform_later(_memproj_fallthrough);
1530     }
1531     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1532       Node *use = _memproj_catchall->fast_out(i);
1533       _igvn.rehash_node_delayed(use);
1534       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1535       // back up iterator
1536       --i;
1537     }
1538     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1539     _igvn.remove_dead_node(_memproj_catchall);
1540   }
1541 
1542   // An allocate node has separate i_o projections for the uses on the control
1543   // and i_o paths. Always replace the control i_o projection with result i_o
1544   // otherwise incoming i_o become dead when only a slow call is generated
1545   // (it is different from memory projections where both projections are
1546   // combined in such case).
1547   if (_ioproj_fallthrough != NULL) {
1548     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1549       Node *use = _ioproj_fallthrough->fast_out(i);
1550       _igvn.rehash_node_delayed(use);
1551       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1552       // back up iterator
1553       --i;
1554     }
1555   }
1556   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1557   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1558   if (_ioproj_catchall != NULL ) {
1559     if (_ioproj_fallthrough == NULL) {
1560       _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O);
1561       transform_later(_ioproj_fallthrough);
1562     }
1563     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1564       Node *use = _ioproj_catchall->fast_out(i);
1565       _igvn.rehash_node_delayed(use);
1566       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1567       // back up iterator
1568       --i;
1569     }
1570     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1571     _igvn.remove_dead_node(_ioproj_catchall);
1572   }
1573 
1574   // if we generated only a slow call, we are done
1575   if (always_slow) {
1576     // Now we can unhook i_o.
1577     if (result_phi_i_o->outcnt() > 1) {
1578       call->set_req(TypeFunc::I_O, top());
1579     } else {
1580       assert(result_phi_i_o->unique_ctrl_out() == call, "");
1581       // Case of new array with negative size known during compilation.
1582       // AllocateArrayNode::Ideal() optimization disconnect unreachable
1583       // following code since call to runtime will throw exception.
1584       // As result there will be no users of i_o after the call.
1585       // Leave i_o attached to this call to avoid problems in preceding graph.
1586     }
1587     return;
1588   }
1589 
1590 
1591   if (_fallthroughcatchproj != NULL) {
1592     ctrl = _fallthroughcatchproj->clone();
1593     transform_later(ctrl);
1594     _igvn.replace_node(_fallthroughcatchproj, result_region);
1595   } else {
1596     ctrl = top();
1597   }
1598   Node *slow_result;
1599   if (_resproj == NULL) {
1600     // no uses of the allocation result
1601     slow_result = top();
1602   } else {
1603     slow_result = _resproj->clone();
1604     transform_later(slow_result);
1605     _igvn.replace_node(_resproj, result_phi_rawoop);
1606   }
1607 
1608   // Plug slow-path into result merge point
1609   result_region    ->init_req( slow_result_path, ctrl );
1610   result_phi_rawoop->init_req( slow_result_path, slow_result);
1611   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1612   transform_later(result_region);
1613   transform_later(result_phi_rawoop);
1614   transform_later(result_phi_rawmem);
1615   transform_later(result_phi_i_o);
1616   // This completes all paths into the result merge point
1617 }
1618 
1619 
1620 // Helper for PhaseMacroExpand::expand_allocate_common.
1621 // Initializes the newly-allocated storage.
1622 Node*
1623 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1624                                     Node* control, Node* rawmem, Node* object,
1625                                     Node* klass_node, Node* length,
1626                                     Node* size_in_bytes) {
1627   InitializeNode* init = alloc->initialization();
1628   // Store the klass & mark bits
1629   Node* mark_node = NULL;
1630   // For now only enable fast locking for non-array types
1631   if (UseBiasedLocking && (length == NULL)) {
1632     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1633   } else {
1634     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1635   }
1636   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1637 
1638   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1639   int header_size = alloc->minimum_header_size();  // conservatively small
1640 
1641   // Array length
1642   if (length != NULL) {         // Arrays need length field
1643     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1644     // conservatively small header size:
1645     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1646     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1647     if (k->is_array_klass())    // we know the exact header size in most cases:
1648       header_size = Klass::layout_helper_header_size(k->layout_helper());
1649   }
1650 
1651   // Clear the object body, if necessary.
1652   if (init == NULL) {
1653     // The init has somehow disappeared; be cautious and clear everything.
1654     //
1655     // This can happen if a node is allocated but an uncommon trap occurs
1656     // immediately.  In this case, the Initialize gets associated with the
1657     // trap, and may be placed in a different (outer) loop, if the Allocate
1658     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
1659     // there can be two Allocates to one Initialize.  The answer in all these
1660     // edge cases is safety first.  It is always safe to clear immediately
1661     // within an Allocate, and then (maybe or maybe not) clear some more later.
1662     if (!ZeroTLAB)
1663       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1664                                             header_size, size_in_bytes,
1665                                             &_igvn);
1666   } else {
1667     if (!init->is_complete()) {
1668       // Try to win by zeroing only what the init does not store.
1669       // We can also try to do some peephole optimizations,
1670       // such as combining some adjacent subword stores.
1671       rawmem = init->complete_stores(control, rawmem, object,
1672                                      header_size, size_in_bytes, &_igvn);
1673     }
1674     // We have no more use for this link, since the AllocateNode goes away:
1675     init->set_req(InitializeNode::RawAddress, top());
1676     // (If we keep the link, it just confuses the register allocator,
1677     // who thinks he sees a real use of the address by the membar.)
1678   }
1679 
1680   return rawmem;
1681 }
1682 
1683 // Generate prefetch instructions for next allocations.
1684 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1685                                         Node*& contended_phi_rawmem,
1686                                         Node* old_eden_top, Node* new_eden_top,
1687                                         Node* length) {
1688    enum { fall_in_path = 1, pf_path = 2 };
1689    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1690       // Generate prefetch allocation with watermark check.
1691       // As an allocation hits the watermark, we will prefetch starting
1692       // at a "distance" away from watermark.
1693 
1694       Node *pf_region = new RegionNode(3);
1695       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1696                                                 TypeRawPtr::BOTTOM );
1697       // I/O is used for Prefetch
1698       Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1699 
1700       Node *thread = new ThreadLocalNode();
1701       transform_later(thread);
1702 
1703       Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1704                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1705       transform_later(eden_pf_adr);
1706 
1707       Node *old_pf_wm = new LoadPNode(needgc_false,
1708                                    contended_phi_rawmem, eden_pf_adr,
1709                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1710                                    MemNode::unordered);
1711       transform_later(old_pf_wm);
1712 
1713       // check against new_eden_top
1714       Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1715       transform_later(need_pf_cmp);
1716       Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1717       transform_later(need_pf_bol);
1718       IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1719                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1720       transform_later(need_pf_iff);
1721 
1722       // true node, add prefetchdistance
1723       Node *need_pf_true = new IfTrueNode( need_pf_iff );
1724       transform_later(need_pf_true);
1725 
1726       Node *need_pf_false = new IfFalseNode( need_pf_iff );
1727       transform_later(need_pf_false);
1728 
1729       Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1730                                     _igvn.MakeConX(AllocatePrefetchDistance) );
1731       transform_later(new_pf_wmt );
1732       new_pf_wmt->set_req(0, need_pf_true);
1733 
1734       Node *store_new_wmt = new StorePNode(need_pf_true,
1735                                        contended_phi_rawmem, eden_pf_adr,
1736                                        TypeRawPtr::BOTTOM, new_pf_wmt,
1737                                        MemNode::unordered);
1738       transform_later(store_new_wmt);
1739 
1740       // adding prefetches
1741       pf_phi_abio->init_req( fall_in_path, i_o );
1742 
1743       Node *prefetch_adr;
1744       Node *prefetch;
1745       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1746       uint step_size = AllocatePrefetchStepSize;
1747       uint distance = 0;
1748 
1749       for ( uint i = 0; i < lines; i++ ) {
1750         prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1751                                             _igvn.MakeConX(distance) );
1752         transform_later(prefetch_adr);
1753         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1754         transform_later(prefetch);
1755         distance += step_size;
1756         i_o = prefetch;
1757       }
1758       pf_phi_abio->set_req( pf_path, i_o );
1759 
1760       pf_region->init_req( fall_in_path, need_pf_false );
1761       pf_region->init_req( pf_path, need_pf_true );
1762 
1763       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1764       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1765 
1766       transform_later(pf_region);
1767       transform_later(pf_phi_rawmem);
1768       transform_later(pf_phi_abio);
1769 
1770       needgc_false = pf_region;
1771       contended_phi_rawmem = pf_phi_rawmem;
1772       i_o = pf_phi_abio;
1773    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1774       // Insert a prefetch for each allocation.
1775       // This code is used for Sparc with BIS.
1776       Node *pf_region = new RegionNode(3);
1777       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1778                                              TypeRawPtr::BOTTOM );
1779       transform_later(pf_region);
1780 
1781       // Generate several prefetch instructions.
1782       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1783       uint step_size = AllocatePrefetchStepSize;
1784       uint distance = AllocatePrefetchDistance;
1785 
1786       // Next cache address.
1787       Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1788                                             _igvn.MakeConX(distance));
1789       transform_later(cache_adr);
1790       cache_adr = new CastP2XNode(needgc_false, cache_adr);
1791       transform_later(cache_adr);
1792       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1793       cache_adr = new AndXNode(cache_adr, mask);
1794       transform_later(cache_adr);
1795       cache_adr = new CastX2PNode(cache_adr);
1796       transform_later(cache_adr);
1797 
1798       // Prefetch
1799       Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1800       prefetch->set_req(0, needgc_false);
1801       transform_later(prefetch);
1802       contended_phi_rawmem = prefetch;
1803       Node *prefetch_adr;
1804       distance = step_size;
1805       for ( uint i = 1; i < lines; i++ ) {
1806         prefetch_adr = new AddPNode( cache_adr, cache_adr,
1807                                             _igvn.MakeConX(distance) );
1808         transform_later(prefetch_adr);
1809         prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1810         transform_later(prefetch);
1811         distance += step_size;
1812         contended_phi_rawmem = prefetch;
1813       }
1814    } else if( AllocatePrefetchStyle > 0 ) {
1815       // Insert a prefetch for each allocation only on the fast-path
1816       Node *prefetch_adr;
1817       Node *prefetch;
1818       // Generate several prefetch instructions.
1819       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1820       uint step_size = AllocatePrefetchStepSize;
1821       uint distance = AllocatePrefetchDistance;
1822       for ( uint i = 0; i < lines; i++ ) {
1823         prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1824                                             _igvn.MakeConX(distance) );
1825         transform_later(prefetch_adr);
1826         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1827         // Do not let it float too high, since if eden_top == eden_end,
1828         // both might be null.
1829         if( i == 0 ) { // Set control for first prefetch, next follows it
1830           prefetch->init_req(0, needgc_false);
1831         }
1832         transform_later(prefetch);
1833         distance += step_size;
1834         i_o = prefetch;
1835       }
1836    }
1837    return i_o;
1838 }
1839 
1840 
1841 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1842   expand_allocate_common(alloc, NULL,
1843                          OptoRuntime::new_instance_Type(),
1844                          OptoRuntime::new_instance_Java());
1845 }
1846 
1847 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1848   Node* length = alloc->in(AllocateNode::ALength);
1849   InitializeNode* init = alloc->initialization();
1850   Node* klass_node = alloc->in(AllocateNode::KlassNode);
1851   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1852   address slow_call_address;  // Address of slow call
1853   if (init != NULL && init->is_complete_with_arraycopy() &&
1854       k->is_type_array_klass()) {
1855     // Don't zero type array during slow allocation in VM since
1856     // it will be initialized later by arraycopy in compiled code.
1857     slow_call_address = OptoRuntime::new_array_nozero_Java();
1858   } else {
1859     slow_call_address = OptoRuntime::new_array_Java();
1860   }
1861   expand_allocate_common(alloc, length,
1862                          OptoRuntime::new_array_Type(),
1863                          slow_call_address);
1864 }
1865 
1866 //-------------------mark_eliminated_box----------------------------------
1867 //
1868 // During EA obj may point to several objects but after few ideal graph
1869 // transformations (CCP) it may point to only one non escaping object
1870 // (but still using phi), corresponding locks and unlocks will be marked
1871 // for elimination. Later obj could be replaced with a new node (new phi)
1872 // and which does not have escape information. And later after some graph
1873 // reshape other locks and unlocks (which were not marked for elimination
1874 // before) are connected to this new obj (phi) but they still will not be
1875 // marked for elimination since new obj has no escape information.
1876 // Mark all associated (same box and obj) lock and unlock nodes for
1877 // elimination if some of them marked already.
1878 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1879   if (oldbox->as_BoxLock()->is_eliminated())
1880     return; // This BoxLock node was processed already.
1881 
1882   // New implementation (EliminateNestedLocks) has separate BoxLock
1883   // node for each locked region so mark all associated locks/unlocks as
1884   // eliminated even if different objects are referenced in one locked region
1885   // (for example, OSR compilation of nested loop inside locked scope).
1886   if (EliminateNestedLocks ||
1887       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
1888     // Box is used only in one lock region. Mark this box as eliminated.
1889     _igvn.hash_delete(oldbox);
1890     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1891     _igvn.hash_insert(oldbox);
1892 
1893     for (uint i = 0; i < oldbox->outcnt(); i++) {
1894       Node* u = oldbox->raw_out(i);
1895       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1896         AbstractLockNode* alock = u->as_AbstractLock();
1897         // Check lock's box since box could be referenced by Lock's debug info.
1898         if (alock->box_node() == oldbox) {
1899           // Mark eliminated all related locks and unlocks.
1900           alock->set_non_esc_obj();
1901         }
1902       }
1903     }
1904     return;
1905   }
1906 
1907   // Create new "eliminated" BoxLock node and use it in monitor debug info
1908   // instead of oldbox for the same object.
1909   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1910 
1911   // Note: BoxLock node is marked eliminated only here and it is used
1912   // to indicate that all associated lock and unlock nodes are marked
1913   // for elimination.
1914   newbox->set_eliminated();
1915   transform_later(newbox);
1916 
1917   // Replace old box node with new box for all users of the same object.
1918   for (uint i = 0; i < oldbox->outcnt();) {
1919     bool next_edge = true;
1920 
1921     Node* u = oldbox->raw_out(i);
1922     if (u->is_AbstractLock()) {
1923       AbstractLockNode* alock = u->as_AbstractLock();
1924       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
1925         // Replace Box and mark eliminated all related locks and unlocks.
1926         alock->set_non_esc_obj();
1927         _igvn.rehash_node_delayed(alock);
1928         alock->set_box_node(newbox);
1929         next_edge = false;
1930       }
1931     }
1932     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
1933       FastLockNode* flock = u->as_FastLock();
1934       assert(flock->box_node() == oldbox, "sanity");
1935       _igvn.rehash_node_delayed(flock);
1936       flock->set_box_node(newbox);
1937       next_edge = false;
1938     }
1939 
1940     // Replace old box in monitor debug info.
1941     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1942       SafePointNode* sfn = u->as_SafePoint();
1943       JVMState* youngest_jvms = sfn->jvms();
1944       int max_depth = youngest_jvms->depth();
1945       for (int depth = 1; depth <= max_depth; depth++) {
1946         JVMState* jvms = youngest_jvms->of_depth(depth);
1947         int num_mon  = jvms->nof_monitors();
1948         // Loop over monitors
1949         for (int idx = 0; idx < num_mon; idx++) {
1950           Node* obj_node = sfn->monitor_obj(jvms, idx);
1951           Node* box_node = sfn->monitor_box(jvms, idx);
1952           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
1953             int j = jvms->monitor_box_offset(idx);
1954             _igvn.replace_input_of(u, j, newbox);
1955             next_edge = false;
1956           }
1957         }
1958       }
1959     }
1960     if (next_edge) i++;
1961   }
1962 }
1963 
1964 //-----------------------mark_eliminated_locking_nodes-----------------------
1965 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1966   if (EliminateNestedLocks) {
1967     if (alock->is_nested()) {
1968        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
1969        return;
1970     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
1971       // Only Lock node has JVMState needed here.
1972       if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
1973         // Mark eliminated related nested locks and unlocks.
1974         Node* obj = alock->obj_node();
1975         BoxLockNode* box_node = alock->box_node()->as_BoxLock();
1976         assert(!box_node->is_eliminated(), "should not be marked yet");
1977         // Note: BoxLock node is marked eliminated only here
1978         // and it is used to indicate that all associated lock
1979         // and unlock nodes are marked for elimination.
1980         box_node->set_eliminated(); // Box's hash is always NO_HASH here
1981         for (uint i = 0; i < box_node->outcnt(); i++) {
1982           Node* u = box_node->raw_out(i);
1983           if (u->is_AbstractLock()) {
1984             alock = u->as_AbstractLock();
1985             if (alock->box_node() == box_node) {
1986               // Verify that this Box is referenced only by related locks.
1987               assert(alock->obj_node()->eqv_uncast(obj), "");
1988               // Mark all related locks and unlocks.
1989               alock->set_nested();
1990             }
1991           }
1992         }
1993       }
1994       return;
1995     }
1996     // Process locks for non escaping object
1997     assert(alock->is_non_esc_obj(), "");
1998   } // EliminateNestedLocks
1999 
2000   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2001     // Look for all locks of this object and mark them and
2002     // corresponding BoxLock nodes as eliminated.
2003     Node* obj = alock->obj_node();
2004     for (uint j = 0; j < obj->outcnt(); j++) {
2005       Node* o = obj->raw_out(j);
2006       if (o->is_AbstractLock() &&
2007           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2008         alock = o->as_AbstractLock();
2009         Node* box = alock->box_node();
2010         // Replace old box node with new eliminated box for all users
2011         // of the same object and mark related locks as eliminated.
2012         mark_eliminated_box(box, obj);
2013       }
2014     }
2015   }
2016 }
2017 
2018 // we have determined that this lock/unlock can be eliminated, we simply
2019 // eliminate the node without expanding it.
2020 //
2021 // Note:  The membar's associated with the lock/unlock are currently not
2022 //        eliminated.  This should be investigated as a future enhancement.
2023 //
2024 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2025 
2026   if (!alock->is_eliminated()) {
2027     return false;
2028   }
2029 #ifdef ASSERT
2030   if (!alock->is_coarsened()) {
2031     // Check that new "eliminated" BoxLock node is created.
2032     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2033     assert(oldbox->is_eliminated(), "should be done already");
2034   }
2035 #endif
2036   CompileLog* log = C->log();
2037   if (log != NULL) {
2038     log->head("eliminate_lock lock='%d'",
2039               alock->is_Lock());
2040     JVMState* p = alock->jvms();
2041     while (p != NULL) {
2042       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
2043       p = p->caller();
2044     }
2045     log->tail("eliminate_lock");
2046   }
2047 
2048   #ifndef PRODUCT
2049   if (PrintEliminateLocks) {
2050     if (alock->is_Lock()) {
2051       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2052     } else {
2053       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2054     }
2055   }
2056   #endif
2057 
2058   Node* mem  = alock->in(TypeFunc::Memory);
2059   Node* ctrl = alock->in(TypeFunc::Control);
2060 
2061   extract_call_projections(alock);
2062   // There are 2 projections from the lock.  The lock node will
2063   // be deleted when its last use is subsumed below.
2064   assert(alock->outcnt() == 2 &&
2065          _fallthroughproj != NULL &&
2066          _memproj_fallthrough != NULL,
2067          "Unexpected projections from Lock/Unlock");
2068 
2069   Node* fallthroughproj = _fallthroughproj;
2070   Node* memproj_fallthrough = _memproj_fallthrough;
2071 
2072   // The memory projection from a lock/unlock is RawMem
2073   // The input to a Lock is merged memory, so extract its RawMem input
2074   // (unless the MergeMem has been optimized away.)
2075   if (alock->is_Lock()) {
2076     // Seach for MemBarAcquireLock node and delete it also.
2077     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2078     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2079     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2080     Node* memproj = membar->proj_out(TypeFunc::Memory);
2081     _igvn.replace_node(ctrlproj, fallthroughproj);
2082     _igvn.replace_node(memproj, memproj_fallthrough);
2083 
2084     // Delete FastLock node also if this Lock node is unique user
2085     // (a loop peeling may clone a Lock node).
2086     Node* flock = alock->as_Lock()->fastlock_node();
2087     if (flock->outcnt() == 1) {
2088       assert(flock->unique_out() == alock, "sanity");
2089       _igvn.replace_node(flock, top());
2090     }
2091   }
2092 
2093   // Seach for MemBarReleaseLock node and delete it also.
2094   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
2095       ctrl->in(0)->is_MemBar()) {
2096     MemBarNode* membar = ctrl->in(0)->as_MemBar();
2097     assert(membar->Opcode() == Op_MemBarReleaseLock &&
2098            mem->is_Proj() && membar == mem->in(0), "");
2099     _igvn.replace_node(fallthroughproj, ctrl);
2100     _igvn.replace_node(memproj_fallthrough, mem);
2101     fallthroughproj = ctrl;
2102     memproj_fallthrough = mem;
2103     ctrl = membar->in(TypeFunc::Control);
2104     mem  = membar->in(TypeFunc::Memory);
2105   }
2106 
2107   _igvn.replace_node(fallthroughproj, ctrl);
2108   _igvn.replace_node(memproj_fallthrough, mem);
2109   return true;
2110 }
2111 
2112 
2113 //------------------------------expand_lock_node----------------------
2114 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2115 
2116   Node* ctrl = lock->in(TypeFunc::Control);
2117   Node* mem = lock->in(TypeFunc::Memory);
2118   Node* obj = lock->obj_node();
2119   Node* box = lock->box_node();
2120   Node* flock = lock->fastlock_node();
2121 
2122   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2123 
2124   // Make the merge point
2125   Node *region;
2126   Node *mem_phi;
2127   Node *slow_path;
2128 
2129   if (UseOptoBiasInlining) {
2130     /*
2131      *  See the full description in MacroAssembler::biased_locking_enter().
2132      *
2133      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2134      *    // The object is biased.
2135      *    proto_node = klass->prototype_header;
2136      *    o_node = thread | proto_node;
2137      *    x_node = o_node ^ mark_word;
2138      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2139      *      // Done.
2140      *    } else {
2141      *      if( (x_node & biased_lock_mask) != 0 ) {
2142      *        // The klass's prototype header is no longer biased.
2143      *        cas(&mark_word, mark_word, proto_node)
2144      *        goto cas_lock;
2145      *      } else {
2146      *        // The klass's prototype header is still biased.
2147      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2148      *          old = mark_word;
2149      *          new = o_node;
2150      *        } else {
2151      *          // Different thread or anonymous biased.
2152      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2153      *          new = thread | old;
2154      *        }
2155      *        // Try to rebias.
2156      *        if( cas(&mark_word, old, new) == 0 ) {
2157      *          // Done.
2158      *        } else {
2159      *          goto slow_path; // Failed.
2160      *        }
2161      *      }
2162      *    }
2163      *  } else {
2164      *    // The object is not biased.
2165      *    cas_lock:
2166      *    if( FastLock(obj) == 0 ) {
2167      *      // Done.
2168      *    } else {
2169      *      slow_path:
2170      *      OptoRuntime::complete_monitor_locking_Java(obj);
2171      *    }
2172      *  }
2173      */
2174 
2175     region  = new RegionNode(5);
2176     // create a Phi for the memory state
2177     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2178 
2179     Node* fast_lock_region  = new RegionNode(3);
2180     Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2181 
2182     // First, check mark word for the biased lock pattern.
2183     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2184 
2185     // Get fast path - mark word has the biased lock pattern.
2186     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2187                          markOopDesc::biased_lock_mask_in_place,
2188                          markOopDesc::biased_lock_pattern, true);
2189     // fast_lock_region->in(1) is set to slow path.
2190     fast_lock_mem_phi->init_req(1, mem);
2191 
2192     // Now check that the lock is biased to the current thread and has
2193     // the same epoch and bias as Klass::_prototype_header.
2194 
2195     // Special-case a fresh allocation to avoid building nodes:
2196     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2197     if (klass_node == NULL) {
2198       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2199       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
2200 #ifdef _LP64
2201       if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2202         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2203         klass_node->in(1)->init_req(0, ctrl);
2204       } else
2205 #endif
2206       klass_node->init_req(0, ctrl);
2207     }
2208     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2209 
2210     Node* thread = transform_later(new ThreadLocalNode());
2211     Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2212     Node* o_node = transform_later(new OrXNode(cast_thread, proto_node));
2213     Node* x_node = transform_later(new XorXNode(o_node, mark_node));
2214 
2215     // Get slow path - mark word does NOT match the value.
2216     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
2217                                       (~markOopDesc::age_mask_in_place), 0);
2218     // region->in(3) is set to fast path - the object is biased to the current thread.
2219     mem_phi->init_req(3, mem);
2220 
2221 
2222     // Mark word does NOT match the value (thread | Klass::_prototype_header).
2223 
2224 
2225     // First, check biased pattern.
2226     // Get fast path - _prototype_header has the same biased lock pattern.
2227     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2228                           markOopDesc::biased_lock_mask_in_place, 0, true);
2229 
2230     not_biased_ctrl = fast_lock_region->in(2); // Slow path
2231     // fast_lock_region->in(2) - the prototype header is no longer biased
2232     // and we have to revoke the bias on this object.
2233     // We are going to try to reset the mark of this object to the prototype
2234     // value and fall through to the CAS-based locking scheme.
2235     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2236     Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr,
2237                                           proto_node, mark_node);
2238     transform_later(cas);
2239     Node* proj = transform_later(new SCMemProjNode(cas));
2240     fast_lock_mem_phi->init_req(2, proj);
2241 
2242 
2243     // Second, check epoch bits.
2244     Node* rebiased_region  = new RegionNode(3);
2245     Node* old_phi = new PhiNode( rebiased_region, TypeX_X);
2246     Node* new_phi = new PhiNode( rebiased_region, TypeX_X);
2247 
2248     // Get slow path - mark word does NOT match epoch bits.
2249     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
2250                                       markOopDesc::epoch_mask_in_place, 0);
2251     // The epoch of the current bias is not valid, attempt to rebias the object
2252     // toward the current thread.
2253     rebiased_region->init_req(2, epoch_ctrl);
2254     old_phi->init_req(2, mark_node);
2255     new_phi->init_req(2, o_node);
2256 
2257     // rebiased_region->in(1) is set to fast path.
2258     // The epoch of the current bias is still valid but we know
2259     // nothing about the owner; it might be set or it might be clear.
2260     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
2261                              markOopDesc::age_mask_in_place |
2262                              markOopDesc::epoch_mask_in_place);
2263     Node* old = transform_later(new AndXNode(mark_node, cmask));
2264     cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2265     Node* new_mark = transform_later(new OrXNode(cast_thread, old));
2266     old_phi->init_req(1, old);
2267     new_phi->init_req(1, new_mark);
2268 
2269     transform_later(rebiased_region);
2270     transform_later(old_phi);
2271     transform_later(new_phi);
2272 
2273     // Try to acquire the bias of the object using an atomic operation.
2274     // If this fails we will go in to the runtime to revoke the object's bias.
2275     cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi);
2276     transform_later(cas);
2277     proj = transform_later(new SCMemProjNode(cas));
2278 
2279     // Get slow path - Failed to CAS.
2280     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2281     mem_phi->init_req(4, proj);
2282     // region->in(4) is set to fast path - the object is rebiased to the current thread.
2283 
2284     // Failed to CAS.
2285     slow_path  = new RegionNode(3);
2286     Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2287 
2288     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2289     slow_mem->init_req(1, proj);
2290 
2291     // Call CAS-based locking scheme (FastLock node).
2292 
2293     transform_later(fast_lock_region);
2294     transform_later(fast_lock_mem_phi);
2295 
2296     // Get slow path - FastLock failed to lock the object.
2297     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2298     mem_phi->init_req(2, fast_lock_mem_phi);
2299     // region->in(2) is set to fast path - the object is locked to the current thread.
2300 
2301     slow_path->init_req(2, ctrl); // Capture slow-control
2302     slow_mem->init_req(2, fast_lock_mem_phi);
2303 
2304     transform_later(slow_path);
2305     transform_later(slow_mem);
2306     // Reset lock's memory edge.
2307     lock->set_req(TypeFunc::Memory, slow_mem);
2308 
2309   } else {
2310     region  = new RegionNode(3);
2311     // create a Phi for the memory state
2312     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2313 
2314     // Optimize test; set region slot 2
2315     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2316     mem_phi->init_req(2, mem);
2317   }
2318 
2319   // Make slow path call
2320   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2321 
2322   extract_call_projections(call);
2323 
2324   // Slow path can only throw asynchronous exceptions, which are always
2325   // de-opted.  So the compiler thinks the slow-call can never throw an
2326   // exception.  If it DOES throw an exception we would need the debug
2327   // info removed first (since if it throws there is no monitor).
2328   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2329            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2330 
2331   // Capture slow path
2332   // disconnect fall-through projection from call and create a new one
2333   // hook up users of fall-through projection to region
2334   Node *slow_ctrl = _fallthroughproj->clone();
2335   transform_later(slow_ctrl);
2336   _igvn.hash_delete(_fallthroughproj);
2337   _fallthroughproj->disconnect_inputs(NULL, C);
2338   region->init_req(1, slow_ctrl);
2339   // region inputs are now complete
2340   transform_later(region);
2341   _igvn.replace_node(_fallthroughproj, region);
2342 
2343   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2344   mem_phi->init_req(1, memproj );
2345   transform_later(mem_phi);
2346   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2347 }
2348 
2349 //------------------------------expand_unlock_node----------------------
2350 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2351 
2352   Node* ctrl = unlock->in(TypeFunc::Control);
2353   Node* mem = unlock->in(TypeFunc::Memory);
2354   Node* obj = unlock->obj_node();
2355   Node* box = unlock->box_node();
2356 
2357   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2358 
2359   // No need for a null check on unlock
2360 
2361   // Make the merge point
2362   Node *region;
2363   Node *mem_phi;
2364 
2365   if (UseOptoBiasInlining) {
2366     // Check for biased locking unlock case, which is a no-op.
2367     // See the full description in MacroAssembler::biased_locking_exit().
2368     region  = new RegionNode(4);
2369     // create a Phi for the memory state
2370     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2371     mem_phi->init_req(3, mem);
2372 
2373     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2374     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2375                          markOopDesc::biased_lock_mask_in_place,
2376                          markOopDesc::biased_lock_pattern);
2377   } else {
2378     region  = new RegionNode(3);
2379     // create a Phi for the memory state
2380     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2381   }
2382 
2383   FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2384   funlock = transform_later( funlock )->as_FastUnlock();
2385   // Optimize test; set region slot 2
2386   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2387 
2388   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 );
2389 
2390   extract_call_projections(call);
2391 
2392   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2393            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2394 
2395   // No exceptions for unlocking
2396   // Capture slow path
2397   // disconnect fall-through projection from call and create a new one
2398   // hook up users of fall-through projection to region
2399   Node *slow_ctrl = _fallthroughproj->clone();
2400   transform_later(slow_ctrl);
2401   _igvn.hash_delete(_fallthroughproj);
2402   _fallthroughproj->disconnect_inputs(NULL, C);
2403   region->init_req(1, slow_ctrl);
2404   // region inputs are now complete
2405   transform_later(region);
2406   _igvn.replace_node(_fallthroughproj, region);
2407 
2408   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2409   mem_phi->init_req(1, memproj );
2410   mem_phi->init_req(2, mem);
2411   transform_later(mem_phi);
2412   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2413 }
2414 
2415 //---------------------------eliminate_macro_nodes----------------------
2416 // Eliminate scalar replaced allocations and associated locks.
2417 void PhaseMacroExpand::eliminate_macro_nodes() {
2418   if (C->macro_count() == 0)
2419     return;
2420 
2421   // First, attempt to eliminate locks
2422   int cnt = C->macro_count();
2423   for (int i=0; i < cnt; i++) {
2424     Node *n = C->macro_node(i);
2425     if (n->is_AbstractLock()) { // Lock and Unlock nodes
2426       // Before elimination mark all associated (same box and obj)
2427       // lock and unlock nodes.
2428       mark_eliminated_locking_nodes(n->as_AbstractLock());
2429     }
2430   }
2431   bool progress = true;
2432   while (progress) {
2433     progress = false;
2434     for (int i = C->macro_count(); i > 0; i--) {
2435       Node * n = C->macro_node(i-1);
2436       bool success = false;
2437       debug_only(int old_macro_count = C->macro_count(););
2438       if (n->is_AbstractLock()) {
2439         success = eliminate_locking_node(n->as_AbstractLock());
2440       }
2441       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2442       progress = progress || success;
2443     }
2444   }
2445   // Next, attempt to eliminate allocations
2446   _has_locks = false;
2447   progress = true;
2448   while (progress) {
2449     progress = false;
2450     for (int i = C->macro_count(); i > 0; i--) {
2451       Node * n = C->macro_node(i-1);
2452       bool success = false;
2453       debug_only(int old_macro_count = C->macro_count(););
2454       switch (n->class_id()) {
2455       case Node::Class_Allocate:
2456       case Node::Class_AllocateArray:
2457         success = eliminate_allocate_node(n->as_Allocate());
2458         break;
2459       case Node::Class_CallStaticJava:
2460         success = eliminate_boxing_node(n->as_CallStaticJava());
2461         break;
2462       case Node::Class_Lock:
2463       case Node::Class_Unlock:
2464         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2465         _has_locks = true;
2466         break;
2467       default:
2468         assert(n->Opcode() == Op_LoopLimit ||
2469                n->Opcode() == Op_Opaque1   ||
2470                n->Opcode() == Op_Opaque2   ||
2471                n->Opcode() == Op_Opaque3, "unknown node type in macro list");
2472       }
2473       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2474       progress = progress || success;
2475     }
2476   }
2477 }
2478 
2479 //------------------------------expand_macro_nodes----------------------
2480 //  Returns true if a failure occurred.
2481 bool PhaseMacroExpand::expand_macro_nodes() {
2482   // Last attempt to eliminate macro nodes.
2483   eliminate_macro_nodes();
2484 
2485   // Make sure expansion will not cause node limit to be exceeded.
2486   // Worst case is a macro node gets expanded into about 50 nodes.
2487   // Allow 50% more for optimization.
2488   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2489     return true;
2490 
2491   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2492   bool progress = true;
2493   while (progress) {
2494     progress = false;
2495     for (int i = C->macro_count(); i > 0; i--) {
2496       Node * n = C->macro_node(i-1);
2497       bool success = false;
2498       debug_only(int old_macro_count = C->macro_count(););
2499       if (n->Opcode() == Op_LoopLimit) {
2500         // Remove it from macro list and put on IGVN worklist to optimize.
2501         C->remove_macro_node(n);
2502         _igvn._worklist.push(n);
2503         success = true;
2504       } else if (n->Opcode() == Op_CallStaticJava) {
2505         // Remove it from macro list and put on IGVN worklist to optimize.
2506         C->remove_macro_node(n);
2507         _igvn._worklist.push(n);
2508         success = true;
2509       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2510         _igvn.replace_node(n, n->in(1));
2511         success = true;
2512 #if INCLUDE_RTM_OPT
2513       } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2514         assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2515         assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2516         Node* cmp = n->unique_out();
2517 #ifdef ASSERT
2518         // Validate graph.
2519         assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2520         BoolNode* bol = cmp->unique_out()->as_Bool();
2521         assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2522                (bol->_test._test == BoolTest::ne), "");
2523         IfNode* ifn = bol->unique_out()->as_If();
2524         assert((ifn->outcnt() == 2) &&
2525                ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change), "");
2526 #endif
2527         Node* repl = n->in(1);
2528         if (!_has_locks) {
2529           // Remove RTM state check if there are no locks in the code.
2530           // Replace input to compare the same value.
2531           repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2532         }
2533         _igvn.replace_node(n, repl);
2534         success = true;
2535 #endif
2536       }
2537       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2538       progress = progress || success;
2539     }
2540   }
2541 
2542   // expand "macro" nodes
2543   // nodes are removed from the macro list as they are processed
2544   while (C->macro_count() > 0) {
2545     int macro_count = C->macro_count();
2546     Node * n = C->macro_node(macro_count-1);
2547     assert(n->is_macro(), "only macro nodes expected here");
2548     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2549       // node is unreachable, so don't try to expand it
2550       C->remove_macro_node(n);
2551       continue;
2552     }
2553     switch (n->class_id()) {
2554     case Node::Class_Allocate:
2555       expand_allocate(n->as_Allocate());
2556       break;
2557     case Node::Class_AllocateArray:
2558       expand_allocate_array(n->as_AllocateArray());
2559       break;
2560     case Node::Class_Lock:
2561       expand_lock_node(n->as_Lock());
2562       break;
2563     case Node::Class_Unlock:
2564       expand_unlock_node(n->as_Unlock());
2565       break;
2566     default:
2567       assert(false, "unknown node type in macro list");
2568     }
2569     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2570     if (C->failing())  return true;
2571   }
2572 
2573   _igvn.set_delay_transform(false);
2574   _igvn.optimize();
2575   if (C->failing())  return true;
2576   return false;
2577 }