src/share/vm/opto/macro.cpp

Tue, 16 Apr 2013 10:08:41 +0200

author
neliasso
date
Tue, 16 Apr 2013 10:08:41 +0200
changeset 4949
8373c19be854
parent 4694
8651f608fea4
child 5110
6f3fd5150b67
permissions
-rw-r--r--

8011621: live_ranges_in_separate_class.patch
Reviewed-by: kvn, roland
Contributed-by: niclas.adlertz@oracle.com

     1 /*
     2  * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "compiler/compileLog.hpp"
    27 #include "libadt/vectset.hpp"
    28 #include "opto/addnode.hpp"
    29 #include "opto/callnode.hpp"
    30 #include "opto/cfgnode.hpp"
    31 #include "opto/compile.hpp"
    32 #include "opto/connode.hpp"
    33 #include "opto/locknode.hpp"
    34 #include "opto/loopnode.hpp"
    35 #include "opto/macro.hpp"
    36 #include "opto/memnode.hpp"
    37 #include "opto/node.hpp"
    38 #include "opto/phaseX.hpp"
    39 #include "opto/rootnode.hpp"
    40 #include "opto/runtime.hpp"
    41 #include "opto/subnode.hpp"
    42 #include "opto/type.hpp"
    43 #include "runtime/sharedRuntime.hpp"
    46 //
    47 // Replace any references to "oldref" in inputs to "use" with "newref".
    48 // Returns the number of replacements made.
    49 //
    50 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
    51   int nreplacements = 0;
    52   uint req = use->req();
    53   for (uint j = 0; j < use->len(); j++) {
    54     Node *uin = use->in(j);
    55     if (uin == oldref) {
    56       if (j < req)
    57         use->set_req(j, newref);
    58       else
    59         use->set_prec(j, newref);
    60       nreplacements++;
    61     } else if (j >= req && uin == NULL) {
    62       break;
    63     }
    64   }
    65   return nreplacements;
    66 }
    68 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
    69   // Copy debug information and adjust JVMState information
    70   uint old_dbg_start = oldcall->tf()->domain()->cnt();
    71   uint new_dbg_start = newcall->tf()->domain()->cnt();
    72   int jvms_adj  = new_dbg_start - old_dbg_start;
    73   assert (new_dbg_start == newcall->req(), "argument count mismatch");
    75   Dict* sosn_map = new Dict(cmpkey,hashkey);
    76   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
    77     Node* old_in = oldcall->in(i);
    78     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
    79     if (old_in != NULL && old_in->is_SafePointScalarObject()) {
    80       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
    81       uint old_unique = C->unique();
    82       Node* new_in = old_sosn->clone(jvms_adj, sosn_map);
    83       if (old_unique != C->unique()) {
    84         new_in->set_req(0, C->root()); // reset control edge
    85         new_in = transform_later(new_in); // Register new node.
    86       }
    87       old_in = new_in;
    88     }
    89     newcall->add_req(old_in);
    90   }
    92   newcall->set_jvms(oldcall->jvms());
    93   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
    94     jvms->set_map(newcall);
    95     jvms->set_locoff(jvms->locoff()+jvms_adj);
    96     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
    97     jvms->set_monoff(jvms->monoff()+jvms_adj);
    98     jvms->set_scloff(jvms->scloff()+jvms_adj);
    99     jvms->set_endoff(jvms->endoff()+jvms_adj);
   100   }
   101 }
   103 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
   104   Node* cmp;
   105   if (mask != 0) {
   106     Node* and_node = transform_later(new (C) AndXNode(word, MakeConX(mask)));
   107     cmp = transform_later(new (C) CmpXNode(and_node, MakeConX(bits)));
   108   } else {
   109     cmp = word;
   110   }
   111   Node* bol = transform_later(new (C) BoolNode(cmp, BoolTest::ne));
   112   IfNode* iff = new (C) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
   113   transform_later(iff);
   115   // Fast path taken.
   116   Node *fast_taken = transform_later( new (C) IfFalseNode(iff) );
   118   // Fast path not-taken, i.e. slow path
   119   Node *slow_taken = transform_later( new (C) IfTrueNode(iff) );
   121   if (return_fast_path) {
   122     region->init_req(edge, slow_taken); // Capture slow-control
   123     return fast_taken;
   124   } else {
   125     region->init_req(edge, fast_taken); // Capture fast-control
   126     return slow_taken;
   127   }
   128 }
   130 //--------------------copy_predefined_input_for_runtime_call--------------------
   131 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
   132   // Set fixed predefined input arguments
   133   call->init_req( TypeFunc::Control, ctrl );
   134   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
   135   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
   136   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
   137   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
   138 }
   140 //------------------------------make_slow_call---------------------------------
   141 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, address slow_call, const char* leaf_name, Node* slow_path, Node* parm0, Node* parm1) {
   143   // Slow-path call
   144  CallNode *call = leaf_name
   145    ? (CallNode*)new (C) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
   146    : (CallNode*)new (C) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
   148   // Slow path call has no side-effects, uses few values
   149   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
   150   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
   151   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
   152   copy_call_debug_info(oldcall, call);
   153   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
   154   _igvn.replace_node(oldcall, call);
   155   transform_later(call);
   157   return call;
   158 }
   160 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
   161   _fallthroughproj = NULL;
   162   _fallthroughcatchproj = NULL;
   163   _ioproj_fallthrough = NULL;
   164   _ioproj_catchall = NULL;
   165   _catchallcatchproj = NULL;
   166   _memproj_fallthrough = NULL;
   167   _memproj_catchall = NULL;
   168   _resproj = NULL;
   169   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
   170     ProjNode *pn = call->fast_out(i)->as_Proj();
   171     switch (pn->_con) {
   172       case TypeFunc::Control:
   173       {
   174         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
   175         _fallthroughproj = pn;
   176         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
   177         const Node *cn = pn->fast_out(j);
   178         if (cn->is_Catch()) {
   179           ProjNode *cpn = NULL;
   180           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
   181             cpn = cn->fast_out(k)->as_Proj();
   182             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
   183             if (cpn->_con == CatchProjNode::fall_through_index)
   184               _fallthroughcatchproj = cpn;
   185             else {
   186               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
   187               _catchallcatchproj = cpn;
   188             }
   189           }
   190         }
   191         break;
   192       }
   193       case TypeFunc::I_O:
   194         if (pn->_is_io_use)
   195           _ioproj_catchall = pn;
   196         else
   197           _ioproj_fallthrough = pn;
   198         break;
   199       case TypeFunc::Memory:
   200         if (pn->_is_io_use)
   201           _memproj_catchall = pn;
   202         else
   203           _memproj_fallthrough = pn;
   204         break;
   205       case TypeFunc::Parms:
   206         _resproj = pn;
   207         break;
   208       default:
   209         assert(false, "unexpected projection from allocation node.");
   210     }
   211   }
   213 }
   215 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
   216 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
   217   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
   218   if (!UseG1GC) {
   219     // vanilla/CMS post barrier
   220     Node *shift = p2x->unique_out();
   221     Node *addp = shift->unique_out();
   222     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
   223       Node *mem = addp->last_out(j);
   224       if (UseCondCardMark && mem->is_Load()) {
   225         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
   226         // The load is checking if the card has been written so
   227         // replace it with zero to fold the test.
   228         _igvn.replace_node(mem, intcon(0));
   229         continue;
   230       }
   231       assert(mem->is_Store(), "store required");
   232       _igvn.replace_node(mem, mem->in(MemNode::Memory));
   233     }
   234   } else {
   235     // G1 pre/post barriers
   236     assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
   237     // It could be only one user, URShift node, in Object.clone() instrinsic
   238     // but the new allocation is passed to arraycopy stub and it could not
   239     // be scalar replaced. So we don't check the case.
   241     // An other case of only one user (Xor) is when the value check for NULL
   242     // in G1 post barrier is folded after CCP so the code which used URShift
   243     // is removed.
   245     // Take Region node before eliminating post barrier since it also
   246     // eliminates CastP2X node when it has only one user.
   247     Node* this_region = p2x->in(0);
   248     assert(this_region != NULL, "");
   250     // Remove G1 post barrier.
   252     // Search for CastP2X->Xor->URShift->Cmp path which
   253     // checks if the store done to a different from the value's region.
   254     // And replace Cmp with #0 (false) to collapse G1 post barrier.
   255     Node* xorx = NULL;
   256     for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
   257       Node* u = p2x->fast_out(i);
   258       if (u->Opcode() == Op_XorX) {
   259         xorx = u;
   260         break;
   261       }
   262     }
   263     assert(xorx != NULL, "missing G1 post barrier");
   264     Node* shift = xorx->unique_out();
   265     Node* cmpx = shift->unique_out();
   266     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
   267     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
   268     "missing region check in G1 post barrier");
   269     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
   271     // Remove G1 pre barrier.
   273     // Search "if (marking != 0)" check and set it to "false".
   274     // There is no G1 pre barrier if previous stored value is NULL
   275     // (for example, after initialization).
   276     if (this_region->is_Region() && this_region->req() == 3) {
   277       int ind = 1;
   278       if (!this_region->in(ind)->is_IfFalse()) {
   279         ind = 2;
   280       }
   281       if (this_region->in(ind)->is_IfFalse()) {
   282         Node* bol = this_region->in(ind)->in(0)->in(1);
   283         assert(bol->is_Bool(), "");
   284         cmpx = bol->in(1);
   285         if (bol->as_Bool()->_test._test == BoolTest::ne &&
   286             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
   287             cmpx->in(1)->is_Load()) {
   288           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
   289           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
   290                                               PtrQueue::byte_offset_of_active());
   291           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
   292               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
   293               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
   294             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
   295           }
   296         }
   297       }
   298     }
   299     // Now CastP2X can be removed since it is used only on dead path
   300     // which currently still alive until igvn optimize it.
   301     assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
   302     _igvn.replace_node(p2x, top());
   303   }
   304 }
   306 // Search for a memory operation for the specified memory slice.
   307 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
   308   Node *orig_mem = mem;
   309   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   310   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
   311   while (true) {
   312     if (mem == alloc_mem || mem == start_mem ) {
   313       return mem;  // hit one of our sentinels
   314     } else if (mem->is_MergeMem()) {
   315       mem = mem->as_MergeMem()->memory_at(alias_idx);
   316     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
   317       Node *in = mem->in(0);
   318       // we can safely skip over safepoints, calls, locks and membars because we
   319       // already know that the object is safe to eliminate.
   320       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
   321         return in;
   322       } else if (in->is_Call()) {
   323         CallNode *call = in->as_Call();
   324         if (!call->may_modify(tinst, phase)) {
   325           mem = call->in(TypeFunc::Memory);
   326         }
   327         mem = in->in(TypeFunc::Memory);
   328       } else if (in->is_MemBar()) {
   329         mem = in->in(TypeFunc::Memory);
   330       } else {
   331         assert(false, "unexpected projection");
   332       }
   333     } else if (mem->is_Store()) {
   334       const TypePtr* atype = mem->as_Store()->adr_type();
   335       int adr_idx = Compile::current()->get_alias_index(atype);
   336       if (adr_idx == alias_idx) {
   337         assert(atype->isa_oopptr(), "address type must be oopptr");
   338         int adr_offset = atype->offset();
   339         uint adr_iid = atype->is_oopptr()->instance_id();
   340         // Array elements references have the same alias_idx
   341         // but different offset and different instance_id.
   342         if (adr_offset == offset && adr_iid == alloc->_idx)
   343           return mem;
   344       } else {
   345         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
   346       }
   347       mem = mem->in(MemNode::Memory);
   348     } else if (mem->is_ClearArray()) {
   349       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
   350         // Can not bypass initialization of the instance
   351         // we are looking.
   352         debug_only(intptr_t offset;)
   353         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
   354         InitializeNode* init = alloc->as_Allocate()->initialization();
   355         // We are looking for stored value, return Initialize node
   356         // or memory edge from Allocate node.
   357         if (init != NULL)
   358           return init;
   359         else
   360           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
   361       }
   362       // Otherwise skip it (the call updated 'mem' value).
   363     } else if (mem->Opcode() == Op_SCMemProj) {
   364       mem = mem->in(0);
   365       Node* adr = NULL;
   366       if (mem->is_LoadStore()) {
   367         adr = mem->in(MemNode::Address);
   368       } else {
   369         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
   370         adr = mem->in(3); // Destination array
   371       }
   372       const TypePtr* atype = adr->bottom_type()->is_ptr();
   373       int adr_idx = Compile::current()->get_alias_index(atype);
   374       if (adr_idx == alias_idx) {
   375         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
   376         return NULL;
   377       }
   378       mem = mem->in(MemNode::Memory);
   379     } else {
   380       return mem;
   381     }
   382     assert(mem != orig_mem, "dead memory loop");
   383   }
   384 }
   386 //
   387 // Given a Memory Phi, compute a value Phi containing the values from stores
   388 // on the input paths.
   389 // Note: this function is recursive, its depth is limied by the "level" argument
   390 // Returns the computed Phi, or NULL if it cannot compute it.
   391 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) {
   392   assert(mem->is_Phi(), "sanity");
   393   int alias_idx = C->get_alias_index(adr_t);
   394   int offset = adr_t->offset();
   395   int instance_id = adr_t->instance_id();
   397   // Check if an appropriate value phi already exists.
   398   Node* region = mem->in(0);
   399   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
   400     Node* phi = region->fast_out(k);
   401     if (phi->is_Phi() && phi != mem &&
   402         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
   403       return phi;
   404     }
   405   }
   406   // Check if an appropriate new value phi already exists.
   407   Node* new_phi = value_phis->find(mem->_idx);
   408   if (new_phi != NULL)
   409     return new_phi;
   411   if (level <= 0) {
   412     return NULL; // Give up: phi tree too deep
   413   }
   414   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   415   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   417   uint length = mem->req();
   418   GrowableArray <Node *> values(length, length, NULL, false);
   420   // create a new Phi for the value
   421   PhiNode *phi = new (C) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
   422   transform_later(phi);
   423   value_phis->push(phi, mem->_idx);
   425   for (uint j = 1; j < length; j++) {
   426     Node *in = mem->in(j);
   427     if (in == NULL || in->is_top()) {
   428       values.at_put(j, in);
   429     } else  {
   430       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
   431       if (val == start_mem || val == alloc_mem) {
   432         // hit a sentinel, return appropriate 0 value
   433         values.at_put(j, _igvn.zerocon(ft));
   434         continue;
   435       }
   436       if (val->is_Initialize()) {
   437         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   438       }
   439       if (val == NULL) {
   440         return NULL;  // can't find a value on this path
   441       }
   442       if (val == mem) {
   443         values.at_put(j, mem);
   444       } else if (val->is_Store()) {
   445         values.at_put(j, val->in(MemNode::ValueIn));
   446       } else if(val->is_Proj() && val->in(0) == alloc) {
   447         values.at_put(j, _igvn.zerocon(ft));
   448       } else if (val->is_Phi()) {
   449         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
   450         if (val == NULL) {
   451           return NULL;
   452         }
   453         values.at_put(j, val);
   454       } else if (val->Opcode() == Op_SCMemProj) {
   455         assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
   456         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
   457         return NULL;
   458       } else {
   459 #ifdef ASSERT
   460         val->dump();
   461         assert(false, "unknown node on this path");
   462 #endif
   463         return NULL;  // unknown node on this path
   464       }
   465     }
   466   }
   467   // Set Phi's inputs
   468   for (uint j = 1; j < length; j++) {
   469     if (values.at(j) == mem) {
   470       phi->init_req(j, phi);
   471     } else {
   472       phi->init_req(j, values.at(j));
   473     }
   474   }
   475   return phi;
   476 }
   478 // Search the last value stored into the object's field.
   479 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
   480   assert(adr_t->is_known_instance_field(), "instance required");
   481   int instance_id = adr_t->instance_id();
   482   assert((uint)instance_id == alloc->_idx, "wrong allocation");
   484   int alias_idx = C->get_alias_index(adr_t);
   485   int offset = adr_t->offset();
   486   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   487   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
   488   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   489   Arena *a = Thread::current()->resource_area();
   490   VectorSet visited(a);
   493   bool done = sfpt_mem == alloc_mem;
   494   Node *mem = sfpt_mem;
   495   while (!done) {
   496     if (visited.test_set(mem->_idx)) {
   497       return NULL;  // found a loop, give up
   498     }
   499     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
   500     if (mem == start_mem || mem == alloc_mem) {
   501       done = true;  // hit a sentinel, return appropriate 0 value
   502     } else if (mem->is_Initialize()) {
   503       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   504       if (mem == NULL) {
   505         done = true; // Something go wrong.
   506       } else if (mem->is_Store()) {
   507         const TypePtr* atype = mem->as_Store()->adr_type();
   508         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
   509         done = true;
   510       }
   511     } else if (mem->is_Store()) {
   512       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
   513       assert(atype != NULL, "address type must be oopptr");
   514       assert(C->get_alias_index(atype) == alias_idx &&
   515              atype->is_known_instance_field() && atype->offset() == offset &&
   516              atype->instance_id() == instance_id, "store is correct memory slice");
   517       done = true;
   518     } else if (mem->is_Phi()) {
   519       // try to find a phi's unique input
   520       Node *unique_input = NULL;
   521       Node *top = C->top();
   522       for (uint i = 1; i < mem->req(); i++) {
   523         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
   524         if (n == NULL || n == top || n == mem) {
   525           continue;
   526         } else if (unique_input == NULL) {
   527           unique_input = n;
   528         } else if (unique_input != n) {
   529           unique_input = top;
   530           break;
   531         }
   532       }
   533       if (unique_input != NULL && unique_input != top) {
   534         mem = unique_input;
   535       } else {
   536         done = true;
   537       }
   538     } else {
   539       assert(false, "unexpected node");
   540     }
   541   }
   542   if (mem != NULL) {
   543     if (mem == start_mem || mem == alloc_mem) {
   544       // hit a sentinel, return appropriate 0 value
   545       return _igvn.zerocon(ft);
   546     } else if (mem->is_Store()) {
   547       return mem->in(MemNode::ValueIn);
   548     } else if (mem->is_Phi()) {
   549       // attempt to produce a Phi reflecting the values on the input paths of the Phi
   550       Node_Stack value_phis(a, 8);
   551       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
   552       if (phi != NULL) {
   553         return phi;
   554       } else {
   555         // Kill all new Phis
   556         while(value_phis.is_nonempty()) {
   557           Node* n = value_phis.node();
   558           _igvn.replace_node(n, C->top());
   559           value_phis.pop();
   560         }
   561       }
   562     }
   563   }
   564   // Something go wrong.
   565   return NULL;
   566 }
   568 // Check the possibility of scalar replacement.
   569 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   570   //  Scan the uses of the allocation to check for anything that would
   571   //  prevent us from eliminating it.
   572   NOT_PRODUCT( const char* fail_eliminate = NULL; )
   573   DEBUG_ONLY( Node* disq_node = NULL; )
   574   bool  can_eliminate = true;
   576   Node* res = alloc->result_cast();
   577   const TypeOopPtr* res_type = NULL;
   578   if (res == NULL) {
   579     // All users were eliminated.
   580   } else if (!res->is_CheckCastPP()) {
   581     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
   582     can_eliminate = false;
   583   } else {
   584     res_type = _igvn.type(res)->isa_oopptr();
   585     if (res_type == NULL) {
   586       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
   587       can_eliminate = false;
   588     } else if (res_type->isa_aryptr()) {
   589       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   590       if (length < 0) {
   591         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
   592         can_eliminate = false;
   593       }
   594     }
   595   }
   597   if (can_eliminate && res != NULL) {
   598     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
   599                                j < jmax && can_eliminate; j++) {
   600       Node* use = res->fast_out(j);
   602       if (use->is_AddP()) {
   603         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
   604         int offset = addp_type->offset();
   606         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
   607           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
   608           can_eliminate = false;
   609           break;
   610         }
   611         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
   612                                    k < kmax && can_eliminate; k++) {
   613           Node* n = use->fast_out(k);
   614           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
   615             DEBUG_ONLY(disq_node = n;)
   616             if (n->is_Load() || n->is_LoadStore()) {
   617               NOT_PRODUCT(fail_eliminate = "Field load";)
   618             } else {
   619               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
   620             }
   621             can_eliminate = false;
   622           }
   623         }
   624       } else if (use->is_SafePoint()) {
   625         SafePointNode* sfpt = use->as_SafePoint();
   626         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
   627           // Object is passed as argument.
   628           DEBUG_ONLY(disq_node = use;)
   629           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
   630           can_eliminate = false;
   631         }
   632         Node* sfptMem = sfpt->memory();
   633         if (sfptMem == NULL || sfptMem->is_top()) {
   634           DEBUG_ONLY(disq_node = use;)
   635           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
   636           can_eliminate = false;
   637         } else {
   638           safepoints.append_if_missing(sfpt);
   639         }
   640       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
   641         if (use->is_Phi()) {
   642           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
   643             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   644           } else {
   645             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
   646           }
   647           DEBUG_ONLY(disq_node = use;)
   648         } else {
   649           if (use->Opcode() == Op_Return) {
   650             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   651           }else {
   652             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
   653           }
   654           DEBUG_ONLY(disq_node = use;)
   655         }
   656         can_eliminate = false;
   657       }
   658     }
   659   }
   661 #ifndef PRODUCT
   662   if (PrintEliminateAllocations) {
   663     if (can_eliminate) {
   664       tty->print("Scalar ");
   665       if (res == NULL)
   666         alloc->dump();
   667       else
   668         res->dump();
   669     } else {
   670       tty->print("NotScalar (%s)", fail_eliminate);
   671       if (res == NULL)
   672         alloc->dump();
   673       else
   674         res->dump();
   675 #ifdef ASSERT
   676       if (disq_node != NULL) {
   677           tty->print("  >>>> ");
   678           disq_node->dump();
   679       }
   680 #endif /*ASSERT*/
   681     }
   682   }
   683 #endif
   684   return can_eliminate;
   685 }
   687 // Do scalar replacement.
   688 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   689   GrowableArray <SafePointNode *> safepoints_done;
   691   ciKlass* klass = NULL;
   692   ciInstanceKlass* iklass = NULL;
   693   int nfields = 0;
   694   int array_base;
   695   int element_size;
   696   BasicType basic_elem_type;
   697   ciType* elem_type;
   699   Node* res = alloc->result_cast();
   700   const TypeOopPtr* res_type = NULL;
   701   if (res != NULL) { // Could be NULL when there are no users
   702     res_type = _igvn.type(res)->isa_oopptr();
   703   }
   705   if (res != NULL) {
   706     klass = res_type->klass();
   707     if (res_type->isa_instptr()) {
   708       // find the fields of the class which will be needed for safepoint debug information
   709       assert(klass->is_instance_klass(), "must be an instance klass.");
   710       iklass = klass->as_instance_klass();
   711       nfields = iklass->nof_nonstatic_fields();
   712     } else {
   713       // find the array's elements which will be needed for safepoint debug information
   714       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   715       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
   716       elem_type = klass->as_array_klass()->element_type();
   717       basic_elem_type = elem_type->basic_type();
   718       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
   719       element_size = type2aelembytes(basic_elem_type);
   720     }
   721   }
   722   //
   723   // Process the safepoint uses
   724   //
   725   while (safepoints.length() > 0) {
   726     SafePointNode* sfpt = safepoints.pop();
   727     Node* mem = sfpt->memory();
   728     uint first_ind = sfpt->req();
   729     SafePointScalarObjectNode* sobj = new (C) SafePointScalarObjectNode(res_type,
   730 #ifdef ASSERT
   731                                                  alloc,
   732 #endif
   733                                                  first_ind, nfields);
   734     sobj->init_req(0, C->root());
   735     transform_later(sobj);
   737     // Scan object's fields adding an input to the safepoint for each field.
   738     for (int j = 0; j < nfields; j++) {
   739       intptr_t offset;
   740       ciField* field = NULL;
   741       if (iklass != NULL) {
   742         field = iklass->nonstatic_field_at(j);
   743         offset = field->offset();
   744         elem_type = field->type();
   745         basic_elem_type = field->layout_type();
   746       } else {
   747         offset = array_base + j * (intptr_t)element_size;
   748       }
   750       const Type *field_type;
   751       // The next code is taken from Parse::do_get_xxx().
   752       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
   753         if (!elem_type->is_loaded()) {
   754           field_type = TypeInstPtr::BOTTOM;
   755         } else if (field != NULL && field->is_constant() && field->is_static()) {
   756           // This can happen if the constant oop is non-perm.
   757           ciObject* con = field->constant_value().as_object();
   758           // Do not "join" in the previous type; it doesn't add value,
   759           // and may yield a vacuous result if the field is of interface type.
   760           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
   761           assert(field_type != NULL, "field singleton type must be consistent");
   762         } else {
   763           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
   764         }
   765         if (UseCompressedOops) {
   766           field_type = field_type->make_narrowoop();
   767           basic_elem_type = T_NARROWOOP;
   768         }
   769       } else {
   770         field_type = Type::get_const_basic_type(basic_elem_type);
   771       }
   773       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
   775       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
   776       if (field_val == NULL) {
   777         // We weren't able to find a value for this field,
   778         // give up on eliminating this allocation.
   780         // Remove any extra entries we added to the safepoint.
   781         uint last = sfpt->req() - 1;
   782         for (int k = 0;  k < j; k++) {
   783           sfpt->del_req(last--);
   784         }
   785         // rollback processed safepoints
   786         while (safepoints_done.length() > 0) {
   787           SafePointNode* sfpt_done = safepoints_done.pop();
   788           // remove any extra entries we added to the safepoint
   789           last = sfpt_done->req() - 1;
   790           for (int k = 0;  k < nfields; k++) {
   791             sfpt_done->del_req(last--);
   792           }
   793           JVMState *jvms = sfpt_done->jvms();
   794           jvms->set_endoff(sfpt_done->req());
   795           // Now make a pass over the debug information replacing any references
   796           // to SafePointScalarObjectNode with the allocated object.
   797           int start = jvms->debug_start();
   798           int end   = jvms->debug_end();
   799           for (int i = start; i < end; i++) {
   800             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
   801               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
   802               if (scobj->first_index() == sfpt_done->req() &&
   803                   scobj->n_fields() == (uint)nfields) {
   804                 assert(scobj->alloc() == alloc, "sanity");
   805                 sfpt_done->set_req(i, res);
   806               }
   807             }
   808           }
   809         }
   810 #ifndef PRODUCT
   811         if (PrintEliminateAllocations) {
   812           if (field != NULL) {
   813             tty->print("=== At SafePoint node %d can't find value of Field: ",
   814                        sfpt->_idx);
   815             field->print();
   816             int field_idx = C->get_alias_index(field_addr_type);
   817             tty->print(" (alias_idx=%d)", field_idx);
   818           } else { // Array's element
   819             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
   820                        sfpt->_idx, j);
   821           }
   822           tty->print(", which prevents elimination of: ");
   823           if (res == NULL)
   824             alloc->dump();
   825           else
   826             res->dump();
   827         }
   828 #endif
   829         return false;
   830       }
   831       if (UseCompressedOops && field_type->isa_narrowoop()) {
   832         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
   833         // to be able scalar replace the allocation.
   834         if (field_val->is_EncodeP()) {
   835           field_val = field_val->in(1);
   836         } else {
   837           field_val = transform_later(new (C) DecodeNNode(field_val, field_val->bottom_type()->make_ptr()));
   838         }
   839       }
   840       sfpt->add_req(field_val);
   841     }
   842     JVMState *jvms = sfpt->jvms();
   843     jvms->set_endoff(sfpt->req());
   844     // Now make a pass over the debug information replacing any references
   845     // to the allocated object with "sobj"
   846     int start = jvms->debug_start();
   847     int end   = jvms->debug_end();
   848     for (int i = start; i < end; i++) {
   849       if (sfpt->in(i) == res) {
   850         sfpt->set_req(i, sobj);
   851       }
   852     }
   853     safepoints_done.append_if_missing(sfpt); // keep it for rollback
   854   }
   855   return true;
   856 }
   858 // Process users of eliminated allocation.
   859 void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
   860   Node* res = alloc->result_cast();
   861   if (res != NULL) {
   862     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
   863       Node *use = res->last_out(j);
   864       uint oc1 = res->outcnt();
   866       if (use->is_AddP()) {
   867         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
   868           Node *n = use->last_out(k);
   869           uint oc2 = use->outcnt();
   870           if (n->is_Store()) {
   871 #ifdef ASSERT
   872             // Verify that there is no dependent MemBarVolatile nodes,
   873             // they should be removed during IGVN, see MemBarNode::Ideal().
   874             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
   875                                        p < pmax; p++) {
   876               Node* mb = n->fast_out(p);
   877               assert(mb->is_Initialize() || !mb->is_MemBar() ||
   878                      mb->req() <= MemBarNode::Precedent ||
   879                      mb->in(MemBarNode::Precedent) != n,
   880                      "MemBarVolatile should be eliminated for non-escaping object");
   881             }
   882 #endif
   883             _igvn.replace_node(n, n->in(MemNode::Memory));
   884           } else {
   885             eliminate_card_mark(n);
   886           }
   887           k -= (oc2 - use->outcnt());
   888         }
   889       } else {
   890         eliminate_card_mark(use);
   891       }
   892       j -= (oc1 - res->outcnt());
   893     }
   894     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
   895     _igvn.remove_dead_node(res);
   896   }
   898   //
   899   // Process other users of allocation's projections
   900   //
   901   if (_resproj != NULL && _resproj->outcnt() != 0) {
   902     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
   903       Node *use = _resproj->last_out(j);
   904       uint oc1 = _resproj->outcnt();
   905       if (use->is_Initialize()) {
   906         // Eliminate Initialize node.
   907         InitializeNode *init = use->as_Initialize();
   908         assert(init->outcnt() <= 2, "only a control and memory projection expected");
   909         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
   910         if (ctrl_proj != NULL) {
   911            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
   912           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
   913         }
   914         Node *mem_proj = init->proj_out(TypeFunc::Memory);
   915         if (mem_proj != NULL) {
   916           Node *mem = init->in(TypeFunc::Memory);
   917 #ifdef ASSERT
   918           if (mem->is_MergeMem()) {
   919             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
   920           } else {
   921             assert(mem == _memproj_fallthrough, "allocation memory projection");
   922           }
   923 #endif
   924           _igvn.replace_node(mem_proj, mem);
   925         }
   926       } else if (use->is_AddP()) {
   927         // raw memory addresses used only by the initialization
   928         _igvn.replace_node(use, C->top());
   929       } else  {
   930         assert(false, "only Initialize or AddP expected");
   931       }
   932       j -= (oc1 - _resproj->outcnt());
   933     }
   934   }
   935   if (_fallthroughcatchproj != NULL) {
   936     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
   937   }
   938   if (_memproj_fallthrough != NULL) {
   939     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
   940   }
   941   if (_memproj_catchall != NULL) {
   942     _igvn.replace_node(_memproj_catchall, C->top());
   943   }
   944   if (_ioproj_fallthrough != NULL) {
   945     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
   946   }
   947   if (_ioproj_catchall != NULL) {
   948     _igvn.replace_node(_ioproj_catchall, C->top());
   949   }
   950   if (_catchallcatchproj != NULL) {
   951     _igvn.replace_node(_catchallcatchproj, C->top());
   952   }
   953 }
   955 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
   957   if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {
   958     return false;
   959   }
   961   extract_call_projections(alloc);
   963   GrowableArray <SafePointNode *> safepoints;
   964   if (!can_eliminate_allocation(alloc, safepoints)) {
   965     return false;
   966   }
   968   if (!scalar_replacement(alloc, safepoints)) {
   969     return false;
   970   }
   972   CompileLog* log = C->log();
   973   if (log != NULL) {
   974     Node* klass = alloc->in(AllocateNode::KlassNode);
   975     const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
   976     log->head("eliminate_allocation type='%d'",
   977               log->identify(tklass->klass()));
   978     JVMState* p = alloc->jvms();
   979     while (p != NULL) {
   980       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
   981       p = p->caller();
   982     }
   983     log->tail("eliminate_allocation");
   984   }
   986   process_users_of_allocation(alloc);
   988 #ifndef PRODUCT
   989   if (PrintEliminateAllocations) {
   990     if (alloc->is_AllocateArray())
   991       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
   992     else
   993       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
   994   }
   995 #endif
   997   return true;
   998 }
  1001 //---------------------------set_eden_pointers-------------------------
  1002 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
  1003   if (UseTLAB) {                // Private allocation: load from TLS
  1004     Node* thread = transform_later(new (C) ThreadLocalNode());
  1005     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
  1006     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
  1007     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
  1008     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
  1009   } else {                      // Shared allocation: load from globals
  1010     CollectedHeap* ch = Universe::heap();
  1011     address top_adr = (address)ch->top_addr();
  1012     address end_adr = (address)ch->end_addr();
  1013     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
  1014     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
  1019 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
  1020   Node* adr = basic_plus_adr(base, offset);
  1021   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
  1022   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
  1023   transform_later(value);
  1024   return value;
  1028 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
  1029   Node* adr = basic_plus_adr(base, offset);
  1030   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
  1031   transform_later(mem);
  1032   return mem;
  1035 //=============================================================================
  1036 //
  1037 //                              A L L O C A T I O N
  1038 //
  1039 // Allocation attempts to be fast in the case of frequent small objects.
  1040 // It breaks down like this:
  1041 //
  1042 // 1) Size in doublewords is computed.  This is a constant for objects and
  1043 // variable for most arrays.  Doubleword units are used to avoid size
  1044 // overflow of huge doubleword arrays.  We need doublewords in the end for
  1045 // rounding.
  1046 //
  1047 // 2) Size is checked for being 'too large'.  Too-large allocations will go
  1048 // the slow path into the VM.  The slow path can throw any required
  1049 // exceptions, and does all the special checks for very large arrays.  The
  1050 // size test can constant-fold away for objects.  For objects with
  1051 // finalizers it constant-folds the otherway: you always go slow with
  1052 // finalizers.
  1053 //
  1054 // 3) If NOT using TLABs, this is the contended loop-back point.
  1055 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
  1056 //
  1057 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
  1058 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
  1059 // "size*8" we always enter the VM, where "largish" is a constant picked small
  1060 // enough that there's always space between the eden max and 4Gig (old space is
  1061 // there so it's quite large) and large enough that the cost of entering the VM
  1062 // is dwarfed by the cost to initialize the space.
  1063 //
  1064 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
  1065 // down.  If contended, repeat at step 3.  If using TLABs normal-store
  1066 // adjusted heap top back down; there is no contention.
  1067 //
  1068 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
  1069 // fields.
  1070 //
  1071 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
  1072 // oop flavor.
  1073 //
  1074 //=============================================================================
  1075 // FastAllocateSizeLimit value is in DOUBLEWORDS.
  1076 // Allocations bigger than this always go the slow route.
  1077 // This value must be small enough that allocation attempts that need to
  1078 // trigger exceptions go the slow route.  Also, it must be small enough so
  1079 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
  1080 //=============================================================================j//
  1081 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
  1082 // The allocator will coalesce int->oop copies away.  See comment in
  1083 // coalesce.cpp about how this works.  It depends critically on the exact
  1084 // code shape produced here, so if you are changing this code shape
  1085 // make sure the GC info for the heap-top is correct in and around the
  1086 // slow-path call.
  1087 //
  1089 void PhaseMacroExpand::expand_allocate_common(
  1090             AllocateNode* alloc, // allocation node to be expanded
  1091             Node* length,  // array length for an array allocation
  1092             const TypeFunc* slow_call_type, // Type of slow call
  1093             address slow_call_address  // Address of slow call
  1097   Node* ctrl = alloc->in(TypeFunc::Control);
  1098   Node* mem  = alloc->in(TypeFunc::Memory);
  1099   Node* i_o  = alloc->in(TypeFunc::I_O);
  1100   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
  1101   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
  1102   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
  1104   assert(ctrl != NULL, "must have control");
  1105   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
  1106   // they will not be used if "always_slow" is set
  1107   enum { slow_result_path = 1, fast_result_path = 2 };
  1108   Node *result_region;
  1109   Node *result_phi_rawmem;
  1110   Node *result_phi_rawoop;
  1111   Node *result_phi_i_o;
  1113   // The initial slow comparison is a size check, the comparison
  1114   // we want to do is a BoolTest::gt
  1115   bool always_slow = false;
  1116   int tv = _igvn.find_int_con(initial_slow_test, -1);
  1117   if (tv >= 0) {
  1118     always_slow = (tv == 1);
  1119     initial_slow_test = NULL;
  1120   } else {
  1121     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
  1124   if (C->env()->dtrace_alloc_probes() ||
  1125       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
  1126                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
  1127     // Force slow-path allocation
  1128     always_slow = true;
  1129     initial_slow_test = NULL;
  1133   enum { too_big_or_final_path = 1, need_gc_path = 2 };
  1134   Node *slow_region = NULL;
  1135   Node *toobig_false = ctrl;
  1137   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
  1138   // generate the initial test if necessary
  1139   if (initial_slow_test != NULL ) {
  1140     slow_region = new (C) RegionNode(3);
  1142     // Now make the initial failure test.  Usually a too-big test but
  1143     // might be a TRUE for finalizers or a fancy class check for
  1144     // newInstance0.
  1145     IfNode *toobig_iff = new (C) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
  1146     transform_later(toobig_iff);
  1147     // Plug the failing-too-big test into the slow-path region
  1148     Node *toobig_true = new (C) IfTrueNode( toobig_iff );
  1149     transform_later(toobig_true);
  1150     slow_region    ->init_req( too_big_or_final_path, toobig_true );
  1151     toobig_false = new (C) IfFalseNode( toobig_iff );
  1152     transform_later(toobig_false);
  1153   } else {         // No initial test, just fall into next case
  1154     toobig_false = ctrl;
  1155     debug_only(slow_region = NodeSentinel);
  1158   Node *slow_mem = mem;  // save the current memory state for slow path
  1159   // generate the fast allocation code unless we know that the initial test will always go slow
  1160   if (!always_slow) {
  1161     // Fast path modifies only raw memory.
  1162     if (mem->is_MergeMem()) {
  1163       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
  1166     Node* eden_top_adr;
  1167     Node* eden_end_adr;
  1169     set_eden_pointers(eden_top_adr, eden_end_adr);
  1171     // Load Eden::end.  Loop invariant and hoisted.
  1172     //
  1173     // Note: We set the control input on "eden_end" and "old_eden_top" when using
  1174     //       a TLAB to work around a bug where these values were being moved across
  1175     //       a safepoint.  These are not oops, so they cannot be include in the oop
  1176     //       map, but they can be changed by a GC.   The proper way to fix this would
  1177     //       be to set the raw memory state when generating a  SafepointNode.  However
  1178     //       this will require extensive changes to the loop optimization in order to
  1179     //       prevent a degradation of the optimization.
  1180     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
  1181     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
  1183     // allocate the Region and Phi nodes for the result
  1184     result_region = new (C) RegionNode(3);
  1185     result_phi_rawmem = new (C) PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1186     result_phi_rawoop = new (C) PhiNode(result_region, TypeRawPtr::BOTTOM);
  1187     result_phi_i_o    = new (C) PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
  1189     // We need a Region for the loop-back contended case.
  1190     enum { fall_in_path = 1, contended_loopback_path = 2 };
  1191     Node *contended_region;
  1192     Node *contended_phi_rawmem;
  1193     if (UseTLAB) {
  1194       contended_region = toobig_false;
  1195       contended_phi_rawmem = mem;
  1196     } else {
  1197       contended_region = new (C) RegionNode(3);
  1198       contended_phi_rawmem = new (C) PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1199       // Now handle the passing-too-big test.  We fall into the contended
  1200       // loop-back merge point.
  1201       contended_region    ->init_req(fall_in_path, toobig_false);
  1202       contended_phi_rawmem->init_req(fall_in_path, mem);
  1203       transform_later(contended_region);
  1204       transform_later(contended_phi_rawmem);
  1207     // Load(-locked) the heap top.
  1208     // See note above concerning the control input when using a TLAB
  1209     Node *old_eden_top = UseTLAB
  1210       ? new (C) LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM)
  1211       : new (C) LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr);
  1213     transform_later(old_eden_top);
  1214     // Add to heap top to get a new heap top
  1215     Node *new_eden_top = new (C) AddPNode(top(), old_eden_top, size_in_bytes);
  1216     transform_later(new_eden_top);
  1217     // Check for needing a GC; compare against heap end
  1218     Node *needgc_cmp = new (C) CmpPNode(new_eden_top, eden_end);
  1219     transform_later(needgc_cmp);
  1220     Node *needgc_bol = new (C) BoolNode(needgc_cmp, BoolTest::ge);
  1221     transform_later(needgc_bol);
  1222     IfNode *needgc_iff = new (C) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
  1223     transform_later(needgc_iff);
  1225     // Plug the failing-heap-space-need-gc test into the slow-path region
  1226     Node *needgc_true = new (C) IfTrueNode(needgc_iff);
  1227     transform_later(needgc_true);
  1228     if (initial_slow_test) {
  1229       slow_region->init_req(need_gc_path, needgc_true);
  1230       // This completes all paths into the slow merge point
  1231       transform_later(slow_region);
  1232     } else {                      // No initial slow path needed!
  1233       // Just fall from the need-GC path straight into the VM call.
  1234       slow_region = needgc_true;
  1236     // No need for a GC.  Setup for the Store-Conditional
  1237     Node *needgc_false = new (C) IfFalseNode(needgc_iff);
  1238     transform_later(needgc_false);
  1240     // Grab regular I/O before optional prefetch may change it.
  1241     // Slow-path does no I/O so just set it to the original I/O.
  1242     result_phi_i_o->init_req(slow_result_path, i_o);
  1244     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
  1245                               old_eden_top, new_eden_top, length);
  1247     // Name successful fast-path variables
  1248     Node* fast_oop = old_eden_top;
  1249     Node* fast_oop_ctrl;
  1250     Node* fast_oop_rawmem;
  1252     // Store (-conditional) the modified eden top back down.
  1253     // StorePConditional produces flags for a test PLUS a modified raw
  1254     // memory state.
  1255     if (UseTLAB) {
  1256       Node* store_eden_top =
  1257         new (C) StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
  1258                               TypeRawPtr::BOTTOM, new_eden_top);
  1259       transform_later(store_eden_top);
  1260       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
  1261       fast_oop_rawmem = store_eden_top;
  1262     } else {
  1263       Node* store_eden_top =
  1264         new (C) StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
  1265                                          new_eden_top, fast_oop/*old_eden_top*/);
  1266       transform_later(store_eden_top);
  1267       Node *contention_check = new (C) BoolNode(store_eden_top, BoolTest::ne);
  1268       transform_later(contention_check);
  1269       store_eden_top = new (C) SCMemProjNode(store_eden_top);
  1270       transform_later(store_eden_top);
  1272       // If not using TLABs, check to see if there was contention.
  1273       IfNode *contention_iff = new (C) IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
  1274       transform_later(contention_iff);
  1275       Node *contention_true = new (C) IfTrueNode(contention_iff);
  1276       transform_later(contention_true);
  1277       // If contention, loopback and try again.
  1278       contended_region->init_req(contended_loopback_path, contention_true);
  1279       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
  1281       // Fast-path succeeded with no contention!
  1282       Node *contention_false = new (C) IfFalseNode(contention_iff);
  1283       transform_later(contention_false);
  1284       fast_oop_ctrl = contention_false;
  1286       // Bump total allocated bytes for this thread
  1287       Node* thread = new (C) ThreadLocalNode();
  1288       transform_later(thread);
  1289       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
  1290                                              in_bytes(JavaThread::allocated_bytes_offset()));
  1291       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
  1292                                     0, TypeLong::LONG, T_LONG);
  1293 #ifdef _LP64
  1294       Node* alloc_size = size_in_bytes;
  1295 #else
  1296       Node* alloc_size = new (C) ConvI2LNode(size_in_bytes);
  1297       transform_later(alloc_size);
  1298 #endif
  1299       Node* new_alloc_bytes = new (C) AddLNode(alloc_bytes, alloc_size);
  1300       transform_later(new_alloc_bytes);
  1301       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
  1302                                    0, new_alloc_bytes, T_LONG);
  1305     InitializeNode* init = alloc->initialization();
  1306     fast_oop_rawmem = initialize_object(alloc,
  1307                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
  1308                                         klass_node, length, size_in_bytes);
  1310     // If initialization is performed by an array copy, any required
  1311     // MemBarStoreStore was already added. If the object does not
  1312     // escape no need for a MemBarStoreStore. Otherwise we need a
  1313     // MemBarStoreStore so that stores that initialize this object
  1314     // can't be reordered with a subsequent store that makes this
  1315     // object accessible by other threads.
  1316     if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
  1317       if (init == NULL || init->req() < InitializeNode::RawStores) {
  1318         // No InitializeNode or no stores captured by zeroing
  1319         // elimination. Simply add the MemBarStoreStore after object
  1320         // initialization.
  1321         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
  1322         transform_later(mb);
  1324         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
  1325         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
  1326         fast_oop_ctrl = new (C) ProjNode(mb,TypeFunc::Control);
  1327         transform_later(fast_oop_ctrl);
  1328         fast_oop_rawmem = new (C) ProjNode(mb,TypeFunc::Memory);
  1329         transform_later(fast_oop_rawmem);
  1330       } else {
  1331         // Add the MemBarStoreStore after the InitializeNode so that
  1332         // all stores performing the initialization that were moved
  1333         // before the InitializeNode happen before the storestore
  1334         // barrier.
  1336         Node* init_ctrl = init->proj_out(TypeFunc::Control);
  1337         Node* init_mem = init->proj_out(TypeFunc::Memory);
  1339         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
  1340         transform_later(mb);
  1342         Node* ctrl = new (C) ProjNode(init,TypeFunc::Control);
  1343         transform_later(ctrl);
  1344         Node* mem = new (C) ProjNode(init,TypeFunc::Memory);
  1345         transform_later(mem);
  1347         // The MemBarStoreStore depends on control and memory coming
  1348         // from the InitializeNode
  1349         mb->init_req(TypeFunc::Memory, mem);
  1350         mb->init_req(TypeFunc::Control, ctrl);
  1352         ctrl = new (C) ProjNode(mb,TypeFunc::Control);
  1353         transform_later(ctrl);
  1354         mem = new (C) ProjNode(mb,TypeFunc::Memory);
  1355         transform_later(mem);
  1357         // All nodes that depended on the InitializeNode for control
  1358         // and memory must now depend on the MemBarNode that itself
  1359         // depends on the InitializeNode
  1360         _igvn.replace_node(init_ctrl, ctrl);
  1361         _igvn.replace_node(init_mem, mem);
  1365     if (C->env()->dtrace_extended_probes()) {
  1366       // Slow-path call
  1367       int size = TypeFunc::Parms + 2;
  1368       CallLeafNode *call = new (C) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
  1369                                                 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
  1370                                                 "dtrace_object_alloc",
  1371                                                 TypeRawPtr::BOTTOM);
  1373       // Get base of thread-local storage area
  1374       Node* thread = new (C) ThreadLocalNode();
  1375       transform_later(thread);
  1377       call->init_req(TypeFunc::Parms+0, thread);
  1378       call->init_req(TypeFunc::Parms+1, fast_oop);
  1379       call->init_req(TypeFunc::Control, fast_oop_ctrl);
  1380       call->init_req(TypeFunc::I_O    , top()); // does no i/o
  1381       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
  1382       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
  1383       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
  1384       transform_later(call);
  1385       fast_oop_ctrl = new (C) ProjNode(call,TypeFunc::Control);
  1386       transform_later(fast_oop_ctrl);
  1387       fast_oop_rawmem = new (C) ProjNode(call,TypeFunc::Memory);
  1388       transform_later(fast_oop_rawmem);
  1391     // Plug in the successful fast-path into the result merge point
  1392     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
  1393     result_phi_rawoop->init_req(fast_result_path, fast_oop);
  1394     result_phi_i_o   ->init_req(fast_result_path, i_o);
  1395     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
  1396   } else {
  1397     slow_region = ctrl;
  1398     result_phi_i_o = i_o; // Rename it to use in the following code.
  1401   // Generate slow-path call
  1402   CallNode *call = new (C) CallStaticJavaNode(slow_call_type, slow_call_address,
  1403                                OptoRuntime::stub_name(slow_call_address),
  1404                                alloc->jvms()->bci(),
  1405                                TypePtr::BOTTOM);
  1406   call->init_req( TypeFunc::Control, slow_region );
  1407   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
  1408   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
  1409   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
  1410   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
  1412   call->init_req(TypeFunc::Parms+0, klass_node);
  1413   if (length != NULL) {
  1414     call->init_req(TypeFunc::Parms+1, length);
  1417   // Copy debug information and adjust JVMState information, then replace
  1418   // allocate node with the call
  1419   copy_call_debug_info((CallNode *) alloc,  call);
  1420   if (!always_slow) {
  1421     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
  1422   } else {
  1423     // Hook i_o projection to avoid its elimination during allocation
  1424     // replacement (when only a slow call is generated).
  1425     call->set_req(TypeFunc::I_O, result_phi_i_o);
  1427   _igvn.replace_node(alloc, call);
  1428   transform_later(call);
  1430   // Identify the output projections from the allocate node and
  1431   // adjust any references to them.
  1432   // The control and io projections look like:
  1433   //
  1434   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
  1435   //  Allocate                   Catch
  1436   //        ^---Proj(io) <-------+   ^---CatchProj(io)
  1437   //
  1438   //  We are interested in the CatchProj nodes.
  1439   //
  1440   extract_call_projections(call);
  1442   // An allocate node has separate memory projections for the uses on
  1443   // the control and i_o paths. Replace the control memory projection with
  1444   // result_phi_rawmem (unless we are only generating a slow call when
  1445   // both memory projections are combined)
  1446   if (!always_slow && _memproj_fallthrough != NULL) {
  1447     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1448       Node *use = _memproj_fallthrough->fast_out(i);
  1449       _igvn.rehash_node_delayed(use);
  1450       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
  1451       // back up iterator
  1452       --i;
  1455   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
  1456   // _memproj_catchall so we end up with a call that has only 1 memory projection.
  1457   if (_memproj_catchall != NULL ) {
  1458     if (_memproj_fallthrough == NULL) {
  1459       _memproj_fallthrough = new (C) ProjNode(call, TypeFunc::Memory);
  1460       transform_later(_memproj_fallthrough);
  1462     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
  1463       Node *use = _memproj_catchall->fast_out(i);
  1464       _igvn.rehash_node_delayed(use);
  1465       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
  1466       // back up iterator
  1467       --i;
  1469     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
  1470     _igvn.remove_dead_node(_memproj_catchall);
  1473   // An allocate node has separate i_o projections for the uses on the control
  1474   // and i_o paths. Always replace the control i_o projection with result i_o
  1475   // otherwise incoming i_o become dead when only a slow call is generated
  1476   // (it is different from memory projections where both projections are
  1477   // combined in such case).
  1478   if (_ioproj_fallthrough != NULL) {
  1479     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1480       Node *use = _ioproj_fallthrough->fast_out(i);
  1481       _igvn.rehash_node_delayed(use);
  1482       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
  1483       // back up iterator
  1484       --i;
  1487   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
  1488   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
  1489   if (_ioproj_catchall != NULL ) {
  1490     if (_ioproj_fallthrough == NULL) {
  1491       _ioproj_fallthrough = new (C) ProjNode(call, TypeFunc::I_O);
  1492       transform_later(_ioproj_fallthrough);
  1494     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
  1495       Node *use = _ioproj_catchall->fast_out(i);
  1496       _igvn.rehash_node_delayed(use);
  1497       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
  1498       // back up iterator
  1499       --i;
  1501     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
  1502     _igvn.remove_dead_node(_ioproj_catchall);
  1505   // if we generated only a slow call, we are done
  1506   if (always_slow) {
  1507     // Now we can unhook i_o.
  1508     if (result_phi_i_o->outcnt() > 1) {
  1509       call->set_req(TypeFunc::I_O, top());
  1510     } else {
  1511       assert(result_phi_i_o->unique_ctrl_out() == call, "");
  1512       // Case of new array with negative size known during compilation.
  1513       // AllocateArrayNode::Ideal() optimization disconnect unreachable
  1514       // following code since call to runtime will throw exception.
  1515       // As result there will be no users of i_o after the call.
  1516       // Leave i_o attached to this call to avoid problems in preceding graph.
  1518     return;
  1522   if (_fallthroughcatchproj != NULL) {
  1523     ctrl = _fallthroughcatchproj->clone();
  1524     transform_later(ctrl);
  1525     _igvn.replace_node(_fallthroughcatchproj, result_region);
  1526   } else {
  1527     ctrl = top();
  1529   Node *slow_result;
  1530   if (_resproj == NULL) {
  1531     // no uses of the allocation result
  1532     slow_result = top();
  1533   } else {
  1534     slow_result = _resproj->clone();
  1535     transform_later(slow_result);
  1536     _igvn.replace_node(_resproj, result_phi_rawoop);
  1539   // Plug slow-path into result merge point
  1540   result_region    ->init_req( slow_result_path, ctrl );
  1541   result_phi_rawoop->init_req( slow_result_path, slow_result);
  1542   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
  1543   transform_later(result_region);
  1544   transform_later(result_phi_rawoop);
  1545   transform_later(result_phi_rawmem);
  1546   transform_later(result_phi_i_o);
  1547   // This completes all paths into the result merge point
  1551 // Helper for PhaseMacroExpand::expand_allocate_common.
  1552 // Initializes the newly-allocated storage.
  1553 Node*
  1554 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
  1555                                     Node* control, Node* rawmem, Node* object,
  1556                                     Node* klass_node, Node* length,
  1557                                     Node* size_in_bytes) {
  1558   InitializeNode* init = alloc->initialization();
  1559   // Store the klass & mark bits
  1560   Node* mark_node = NULL;
  1561   // For now only enable fast locking for non-array types
  1562   if (UseBiasedLocking && (length == NULL)) {
  1563     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
  1564   } else {
  1565     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
  1567   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
  1569   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
  1570   int header_size = alloc->minimum_header_size();  // conservatively small
  1572   // Array length
  1573   if (length != NULL) {         // Arrays need length field
  1574     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
  1575     // conservatively small header size:
  1576     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1577     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1578     if (k->is_array_klass())    // we know the exact header size in most cases:
  1579       header_size = Klass::layout_helper_header_size(k->layout_helper());
  1582   // Clear the object body, if necessary.
  1583   if (init == NULL) {
  1584     // The init has somehow disappeared; be cautious and clear everything.
  1585     //
  1586     // This can happen if a node is allocated but an uncommon trap occurs
  1587     // immediately.  In this case, the Initialize gets associated with the
  1588     // trap, and may be placed in a different (outer) loop, if the Allocate
  1589     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
  1590     // there can be two Allocates to one Initialize.  The answer in all these
  1591     // edge cases is safety first.  It is always safe to clear immediately
  1592     // within an Allocate, and then (maybe or maybe not) clear some more later.
  1593     if (!ZeroTLAB)
  1594       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
  1595                                             header_size, size_in_bytes,
  1596                                             &_igvn);
  1597   } else {
  1598     if (!init->is_complete()) {
  1599       // Try to win by zeroing only what the init does not store.
  1600       // We can also try to do some peephole optimizations,
  1601       // such as combining some adjacent subword stores.
  1602       rawmem = init->complete_stores(control, rawmem, object,
  1603                                      header_size, size_in_bytes, &_igvn);
  1605     // We have no more use for this link, since the AllocateNode goes away:
  1606     init->set_req(InitializeNode::RawAddress, top());
  1607     // (If we keep the link, it just confuses the register allocator,
  1608     // who thinks he sees a real use of the address by the membar.)
  1611   return rawmem;
  1614 // Generate prefetch instructions for next allocations.
  1615 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
  1616                                         Node*& contended_phi_rawmem,
  1617                                         Node* old_eden_top, Node* new_eden_top,
  1618                                         Node* length) {
  1619    enum { fall_in_path = 1, pf_path = 2 };
  1620    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
  1621       // Generate prefetch allocation with watermark check.
  1622       // As an allocation hits the watermark, we will prefetch starting
  1623       // at a "distance" away from watermark.
  1625       Node *pf_region = new (C) RegionNode(3);
  1626       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
  1627                                                 TypeRawPtr::BOTTOM );
  1628       // I/O is used for Prefetch
  1629       Node *pf_phi_abio = new (C) PhiNode( pf_region, Type::ABIO );
  1631       Node *thread = new (C) ThreadLocalNode();
  1632       transform_later(thread);
  1634       Node *eden_pf_adr = new (C) AddPNode( top()/*not oop*/, thread,
  1635                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
  1636       transform_later(eden_pf_adr);
  1638       Node *old_pf_wm = new (C) LoadPNode( needgc_false,
  1639                                    contended_phi_rawmem, eden_pf_adr,
  1640                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
  1641       transform_later(old_pf_wm);
  1643       // check against new_eden_top
  1644       Node *need_pf_cmp = new (C) CmpPNode( new_eden_top, old_pf_wm );
  1645       transform_later(need_pf_cmp);
  1646       Node *need_pf_bol = new (C) BoolNode( need_pf_cmp, BoolTest::ge );
  1647       transform_later(need_pf_bol);
  1648       IfNode *need_pf_iff = new (C) IfNode( needgc_false, need_pf_bol,
  1649                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
  1650       transform_later(need_pf_iff);
  1652       // true node, add prefetchdistance
  1653       Node *need_pf_true = new (C) IfTrueNode( need_pf_iff );
  1654       transform_later(need_pf_true);
  1656       Node *need_pf_false = new (C) IfFalseNode( need_pf_iff );
  1657       transform_later(need_pf_false);
  1659       Node *new_pf_wmt = new (C) AddPNode( top(), old_pf_wm,
  1660                                     _igvn.MakeConX(AllocatePrefetchDistance) );
  1661       transform_later(new_pf_wmt );
  1662       new_pf_wmt->set_req(0, need_pf_true);
  1664       Node *store_new_wmt = new (C) StorePNode( need_pf_true,
  1665                                        contended_phi_rawmem, eden_pf_adr,
  1666                                        TypeRawPtr::BOTTOM, new_pf_wmt );
  1667       transform_later(store_new_wmt);
  1669       // adding prefetches
  1670       pf_phi_abio->init_req( fall_in_path, i_o );
  1672       Node *prefetch_adr;
  1673       Node *prefetch;
  1674       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
  1675       uint step_size = AllocatePrefetchStepSize;
  1676       uint distance = 0;
  1678       for ( uint i = 0; i < lines; i++ ) {
  1679         prefetch_adr = new (C) AddPNode( old_pf_wm, new_pf_wmt,
  1680                                             _igvn.MakeConX(distance) );
  1681         transform_later(prefetch_adr);
  1682         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
  1683         transform_later(prefetch);
  1684         distance += step_size;
  1685         i_o = prefetch;
  1687       pf_phi_abio->set_req( pf_path, i_o );
  1689       pf_region->init_req( fall_in_path, need_pf_false );
  1690       pf_region->init_req( pf_path, need_pf_true );
  1692       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
  1693       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
  1695       transform_later(pf_region);
  1696       transform_later(pf_phi_rawmem);
  1697       transform_later(pf_phi_abio);
  1699       needgc_false = pf_region;
  1700       contended_phi_rawmem = pf_phi_rawmem;
  1701       i_o = pf_phi_abio;
  1702    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
  1703       // Insert a prefetch for each allocation.
  1704       // This code is used for Sparc with BIS.
  1705       Node *pf_region = new (C) RegionNode(3);
  1706       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
  1707                                              TypeRawPtr::BOTTOM );
  1709       // Generate several prefetch instructions.
  1710       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
  1711       uint step_size = AllocatePrefetchStepSize;
  1712       uint distance = AllocatePrefetchDistance;
  1714       // Next cache address.
  1715       Node *cache_adr = new (C) AddPNode(old_eden_top, old_eden_top,
  1716                                             _igvn.MakeConX(distance));
  1717       transform_later(cache_adr);
  1718       cache_adr = new (C) CastP2XNode(needgc_false, cache_adr);
  1719       transform_later(cache_adr);
  1720       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
  1721       cache_adr = new (C) AndXNode(cache_adr, mask);
  1722       transform_later(cache_adr);
  1723       cache_adr = new (C) CastX2PNode(cache_adr);
  1724       transform_later(cache_adr);
  1726       // Prefetch
  1727       Node *prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
  1728       prefetch->set_req(0, needgc_false);
  1729       transform_later(prefetch);
  1730       contended_phi_rawmem = prefetch;
  1731       Node *prefetch_adr;
  1732       distance = step_size;
  1733       for ( uint i = 1; i < lines; i++ ) {
  1734         prefetch_adr = new (C) AddPNode( cache_adr, cache_adr,
  1735                                             _igvn.MakeConX(distance) );
  1736         transform_later(prefetch_adr);
  1737         prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
  1738         transform_later(prefetch);
  1739         distance += step_size;
  1740         contended_phi_rawmem = prefetch;
  1742    } else if( AllocatePrefetchStyle > 0 ) {
  1743       // Insert a prefetch for each allocation only on the fast-path
  1744       Node *prefetch_adr;
  1745       Node *prefetch;
  1746       // Generate several prefetch instructions.
  1747       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
  1748       uint step_size = AllocatePrefetchStepSize;
  1749       uint distance = AllocatePrefetchDistance;
  1750       for ( uint i = 0; i < lines; i++ ) {
  1751         prefetch_adr = new (C) AddPNode( old_eden_top, new_eden_top,
  1752                                             _igvn.MakeConX(distance) );
  1753         transform_later(prefetch_adr);
  1754         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
  1755         // Do not let it float too high, since if eden_top == eden_end,
  1756         // both might be null.
  1757         if( i == 0 ) { // Set control for first prefetch, next follows it
  1758           prefetch->init_req(0, needgc_false);
  1760         transform_later(prefetch);
  1761         distance += step_size;
  1762         i_o = prefetch;
  1765    return i_o;
  1769 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
  1770   expand_allocate_common(alloc, NULL,
  1771                          OptoRuntime::new_instance_Type(),
  1772                          OptoRuntime::new_instance_Java());
  1775 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
  1776   Node* length = alloc->in(AllocateNode::ALength);
  1777   InitializeNode* init = alloc->initialization();
  1778   Node* klass_node = alloc->in(AllocateNode::KlassNode);
  1779   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1780   address slow_call_address;  // Address of slow call
  1781   if (init != NULL && init->is_complete_with_arraycopy() &&
  1782       k->is_type_array_klass()) {
  1783     // Don't zero type array during slow allocation in VM since
  1784     // it will be initialized later by arraycopy in compiled code.
  1785     slow_call_address = OptoRuntime::new_array_nozero_Java();
  1786   } else {
  1787     slow_call_address = OptoRuntime::new_array_Java();
  1789   expand_allocate_common(alloc, length,
  1790                          OptoRuntime::new_array_Type(),
  1791                          slow_call_address);
  1794 //-------------------mark_eliminated_box----------------------------------
  1795 //
  1796 // During EA obj may point to several objects but after few ideal graph
  1797 // transformations (CCP) it may point to only one non escaping object
  1798 // (but still using phi), corresponding locks and unlocks will be marked
  1799 // for elimination. Later obj could be replaced with a new node (new phi)
  1800 // and which does not have escape information. And later after some graph
  1801 // reshape other locks and unlocks (which were not marked for elimination
  1802 // before) are connected to this new obj (phi) but they still will not be
  1803 // marked for elimination since new obj has no escape information.
  1804 // Mark all associated (same box and obj) lock and unlock nodes for
  1805 // elimination if some of them marked already.
  1806 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
  1807   if (oldbox->as_BoxLock()->is_eliminated())
  1808     return; // This BoxLock node was processed already.
  1810   // New implementation (EliminateNestedLocks) has separate BoxLock
  1811   // node for each locked region so mark all associated locks/unlocks as
  1812   // eliminated even if different objects are referenced in one locked region
  1813   // (for example, OSR compilation of nested loop inside locked scope).
  1814   if (EliminateNestedLocks ||
  1815       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
  1816     // Box is used only in one lock region. Mark this box as eliminated.
  1817     _igvn.hash_delete(oldbox);
  1818     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
  1819     _igvn.hash_insert(oldbox);
  1821     for (uint i = 0; i < oldbox->outcnt(); i++) {
  1822       Node* u = oldbox->raw_out(i);
  1823       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
  1824         AbstractLockNode* alock = u->as_AbstractLock();
  1825         // Check lock's box since box could be referenced by Lock's debug info.
  1826         if (alock->box_node() == oldbox) {
  1827           // Mark eliminated all related locks and unlocks.
  1828           alock->set_non_esc_obj();
  1832     return;
  1835   // Create new "eliminated" BoxLock node and use it in monitor debug info
  1836   // instead of oldbox for the same object.
  1837   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
  1839   // Note: BoxLock node is marked eliminated only here and it is used
  1840   // to indicate that all associated lock and unlock nodes are marked
  1841   // for elimination.
  1842   newbox->set_eliminated();
  1843   transform_later(newbox);
  1845   // Replace old box node with new box for all users of the same object.
  1846   for (uint i = 0; i < oldbox->outcnt();) {
  1847     bool next_edge = true;
  1849     Node* u = oldbox->raw_out(i);
  1850     if (u->is_AbstractLock()) {
  1851       AbstractLockNode* alock = u->as_AbstractLock();
  1852       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
  1853         // Replace Box and mark eliminated all related locks and unlocks.
  1854         alock->set_non_esc_obj();
  1855         _igvn.rehash_node_delayed(alock);
  1856         alock->set_box_node(newbox);
  1857         next_edge = false;
  1860     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
  1861       FastLockNode* flock = u->as_FastLock();
  1862       assert(flock->box_node() == oldbox, "sanity");
  1863       _igvn.rehash_node_delayed(flock);
  1864       flock->set_box_node(newbox);
  1865       next_edge = false;
  1868     // Replace old box in monitor debug info.
  1869     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
  1870       SafePointNode* sfn = u->as_SafePoint();
  1871       JVMState* youngest_jvms = sfn->jvms();
  1872       int max_depth = youngest_jvms->depth();
  1873       for (int depth = 1; depth <= max_depth; depth++) {
  1874         JVMState* jvms = youngest_jvms->of_depth(depth);
  1875         int num_mon  = jvms->nof_monitors();
  1876         // Loop over monitors
  1877         for (int idx = 0; idx < num_mon; idx++) {
  1878           Node* obj_node = sfn->monitor_obj(jvms, idx);
  1879           Node* box_node = sfn->monitor_box(jvms, idx);
  1880           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
  1881             int j = jvms->monitor_box_offset(idx);
  1882             _igvn.replace_input_of(u, j, newbox);
  1883             next_edge = false;
  1888     if (next_edge) i++;
  1892 //-----------------------mark_eliminated_locking_nodes-----------------------
  1893 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
  1894   if (EliminateNestedLocks) {
  1895     if (alock->is_nested()) {
  1896        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
  1897        return;
  1898     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
  1899       // Only Lock node has JVMState needed here.
  1900       if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
  1901         // Mark eliminated related nested locks and unlocks.
  1902         Node* obj = alock->obj_node();
  1903         BoxLockNode* box_node = alock->box_node()->as_BoxLock();
  1904         assert(!box_node->is_eliminated(), "should not be marked yet");
  1905         // Note: BoxLock node is marked eliminated only here
  1906         // and it is used to indicate that all associated lock
  1907         // and unlock nodes are marked for elimination.
  1908         box_node->set_eliminated(); // Box's hash is always NO_HASH here
  1909         for (uint i = 0; i < box_node->outcnt(); i++) {
  1910           Node* u = box_node->raw_out(i);
  1911           if (u->is_AbstractLock()) {
  1912             alock = u->as_AbstractLock();
  1913             if (alock->box_node() == box_node) {
  1914               // Verify that this Box is referenced only by related locks.
  1915               assert(alock->obj_node()->eqv_uncast(obj), "");
  1916               // Mark all related locks and unlocks.
  1917               alock->set_nested();
  1922       return;
  1924     // Process locks for non escaping object
  1925     assert(alock->is_non_esc_obj(), "");
  1926   } // EliminateNestedLocks
  1928   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
  1929     // Look for all locks of this object and mark them and
  1930     // corresponding BoxLock nodes as eliminated.
  1931     Node* obj = alock->obj_node();
  1932     for (uint j = 0; j < obj->outcnt(); j++) {
  1933       Node* o = obj->raw_out(j);
  1934       if (o->is_AbstractLock() &&
  1935           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
  1936         alock = o->as_AbstractLock();
  1937         Node* box = alock->box_node();
  1938         // Replace old box node with new eliminated box for all users
  1939         // of the same object and mark related locks as eliminated.
  1940         mark_eliminated_box(box, obj);
  1946 // we have determined that this lock/unlock can be eliminated, we simply
  1947 // eliminate the node without expanding it.
  1948 //
  1949 // Note:  The membar's associated with the lock/unlock are currently not
  1950 //        eliminated.  This should be investigated as a future enhancement.
  1951 //
  1952 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
  1954   if (!alock->is_eliminated()) {
  1955     return false;
  1957 #ifdef ASSERT
  1958   if (!alock->is_coarsened()) {
  1959     // Check that new "eliminated" BoxLock node is created.
  1960     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
  1961     assert(oldbox->is_eliminated(), "should be done already");
  1963 #endif
  1964   CompileLog* log = C->log();
  1965   if (log != NULL) {
  1966     log->head("eliminate_lock lock='%d'",
  1967               alock->is_Lock());
  1968     JVMState* p = alock->jvms();
  1969     while (p != NULL) {
  1970       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
  1971       p = p->caller();
  1973     log->tail("eliminate_lock");
  1976   #ifndef PRODUCT
  1977   if (PrintEliminateLocks) {
  1978     if (alock->is_Lock()) {
  1979       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
  1980     } else {
  1981       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
  1984   #endif
  1986   Node* mem  = alock->in(TypeFunc::Memory);
  1987   Node* ctrl = alock->in(TypeFunc::Control);
  1989   extract_call_projections(alock);
  1990   // There are 2 projections from the lock.  The lock node will
  1991   // be deleted when its last use is subsumed below.
  1992   assert(alock->outcnt() == 2 &&
  1993          _fallthroughproj != NULL &&
  1994          _memproj_fallthrough != NULL,
  1995          "Unexpected projections from Lock/Unlock");
  1997   Node* fallthroughproj = _fallthroughproj;
  1998   Node* memproj_fallthrough = _memproj_fallthrough;
  2000   // The memory projection from a lock/unlock is RawMem
  2001   // The input to a Lock is merged memory, so extract its RawMem input
  2002   // (unless the MergeMem has been optimized away.)
  2003   if (alock->is_Lock()) {
  2004     // Seach for MemBarAcquireLock node and delete it also.
  2005     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
  2006     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
  2007     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
  2008     Node* memproj = membar->proj_out(TypeFunc::Memory);
  2009     _igvn.replace_node(ctrlproj, fallthroughproj);
  2010     _igvn.replace_node(memproj, memproj_fallthrough);
  2012     // Delete FastLock node also if this Lock node is unique user
  2013     // (a loop peeling may clone a Lock node).
  2014     Node* flock = alock->as_Lock()->fastlock_node();
  2015     if (flock->outcnt() == 1) {
  2016       assert(flock->unique_out() == alock, "sanity");
  2017       _igvn.replace_node(flock, top());
  2021   // Seach for MemBarReleaseLock node and delete it also.
  2022   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
  2023       ctrl->in(0)->is_MemBar()) {
  2024     MemBarNode* membar = ctrl->in(0)->as_MemBar();
  2025     assert(membar->Opcode() == Op_MemBarReleaseLock &&
  2026            mem->is_Proj() && membar == mem->in(0), "");
  2027     _igvn.replace_node(fallthroughproj, ctrl);
  2028     _igvn.replace_node(memproj_fallthrough, mem);
  2029     fallthroughproj = ctrl;
  2030     memproj_fallthrough = mem;
  2031     ctrl = membar->in(TypeFunc::Control);
  2032     mem  = membar->in(TypeFunc::Memory);
  2035   _igvn.replace_node(fallthroughproj, ctrl);
  2036   _igvn.replace_node(memproj_fallthrough, mem);
  2037   return true;
  2041 //------------------------------expand_lock_node----------------------
  2042 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
  2044   Node* ctrl = lock->in(TypeFunc::Control);
  2045   Node* mem = lock->in(TypeFunc::Memory);
  2046   Node* obj = lock->obj_node();
  2047   Node* box = lock->box_node();
  2048   Node* flock = lock->fastlock_node();
  2050   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
  2052   // Make the merge point
  2053   Node *region;
  2054   Node *mem_phi;
  2055   Node *slow_path;
  2057   if (UseOptoBiasInlining) {
  2058     /*
  2059      *  See the full description in MacroAssembler::biased_locking_enter().
  2061      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
  2062      *    // The object is biased.
  2063      *    proto_node = klass->prototype_header;
  2064      *    o_node = thread | proto_node;
  2065      *    x_node = o_node ^ mark_word;
  2066      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
  2067      *      // Done.
  2068      *    } else {
  2069      *      if( (x_node & biased_lock_mask) != 0 ) {
  2070      *        // The klass's prototype header is no longer biased.
  2071      *        cas(&mark_word, mark_word, proto_node)
  2072      *        goto cas_lock;
  2073      *      } else {
  2074      *        // The klass's prototype header is still biased.
  2075      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
  2076      *          old = mark_word;
  2077      *          new = o_node;
  2078      *        } else {
  2079      *          // Different thread or anonymous biased.
  2080      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
  2081      *          new = thread | old;
  2082      *        }
  2083      *        // Try to rebias.
  2084      *        if( cas(&mark_word, old, new) == 0 ) {
  2085      *          // Done.
  2086      *        } else {
  2087      *          goto slow_path; // Failed.
  2088      *        }
  2089      *      }
  2090      *    }
  2091      *  } else {
  2092      *    // The object is not biased.
  2093      *    cas_lock:
  2094      *    if( FastLock(obj) == 0 ) {
  2095      *      // Done.
  2096      *    } else {
  2097      *      slow_path:
  2098      *      OptoRuntime::complete_monitor_locking_Java(obj);
  2099      *    }
  2100      *  }
  2101      */
  2103     region  = new (C) RegionNode(5);
  2104     // create a Phi for the memory state
  2105     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2107     Node* fast_lock_region  = new (C) RegionNode(3);
  2108     Node* fast_lock_mem_phi = new (C) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2110     // First, check mark word for the biased lock pattern.
  2111     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  2113     // Get fast path - mark word has the biased lock pattern.
  2114     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
  2115                          markOopDesc::biased_lock_mask_in_place,
  2116                          markOopDesc::biased_lock_pattern, true);
  2117     // fast_lock_region->in(1) is set to slow path.
  2118     fast_lock_mem_phi->init_req(1, mem);
  2120     // Now check that the lock is biased to the current thread and has
  2121     // the same epoch and bias as Klass::_prototype_header.
  2123     // Special-case a fresh allocation to avoid building nodes:
  2124     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
  2125     if (klass_node == NULL) {
  2126       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
  2127       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
  2128 #ifdef _LP64
  2129       if (UseCompressedKlassPointers && klass_node->is_DecodeNKlass()) {
  2130         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
  2131         klass_node->in(1)->init_req(0, ctrl);
  2132       } else
  2133 #endif
  2134       klass_node->init_req(0, ctrl);
  2136     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
  2138     Node* thread = transform_later(new (C) ThreadLocalNode());
  2139     Node* cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
  2140     Node* o_node = transform_later(new (C) OrXNode(cast_thread, proto_node));
  2141     Node* x_node = transform_later(new (C) XorXNode(o_node, mark_node));
  2143     // Get slow path - mark word does NOT match the value.
  2144     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
  2145                                       (~markOopDesc::age_mask_in_place), 0);
  2146     // region->in(3) is set to fast path - the object is biased to the current thread.
  2147     mem_phi->init_req(3, mem);
  2150     // Mark word does NOT match the value (thread | Klass::_prototype_header).
  2153     // First, check biased pattern.
  2154     // Get fast path - _prototype_header has the same biased lock pattern.
  2155     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
  2156                           markOopDesc::biased_lock_mask_in_place, 0, true);
  2158     not_biased_ctrl = fast_lock_region->in(2); // Slow path
  2159     // fast_lock_region->in(2) - the prototype header is no longer biased
  2160     // and we have to revoke the bias on this object.
  2161     // We are going to try to reset the mark of this object to the prototype
  2162     // value and fall through to the CAS-based locking scheme.
  2163     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
  2164     Node* cas = new (C) StoreXConditionalNode(not_biased_ctrl, mem, adr,
  2165                                               proto_node, mark_node);
  2166     transform_later(cas);
  2167     Node* proj = transform_later( new (C) SCMemProjNode(cas));
  2168     fast_lock_mem_phi->init_req(2, proj);
  2171     // Second, check epoch bits.
  2172     Node* rebiased_region  = new (C) RegionNode(3);
  2173     Node* old_phi = new (C) PhiNode( rebiased_region, TypeX_X);
  2174     Node* new_phi = new (C) PhiNode( rebiased_region, TypeX_X);
  2176     // Get slow path - mark word does NOT match epoch bits.
  2177     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
  2178                                       markOopDesc::epoch_mask_in_place, 0);
  2179     // The epoch of the current bias is not valid, attempt to rebias the object
  2180     // toward the current thread.
  2181     rebiased_region->init_req(2, epoch_ctrl);
  2182     old_phi->init_req(2, mark_node);
  2183     new_phi->init_req(2, o_node);
  2185     // rebiased_region->in(1) is set to fast path.
  2186     // The epoch of the current bias is still valid but we know
  2187     // nothing about the owner; it might be set or it might be clear.
  2188     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
  2189                              markOopDesc::age_mask_in_place |
  2190                              markOopDesc::epoch_mask_in_place);
  2191     Node* old = transform_later(new (C) AndXNode(mark_node, cmask));
  2192     cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
  2193     Node* new_mark = transform_later(new (C) OrXNode(cast_thread, old));
  2194     old_phi->init_req(1, old);
  2195     new_phi->init_req(1, new_mark);
  2197     transform_later(rebiased_region);
  2198     transform_later(old_phi);
  2199     transform_later(new_phi);
  2201     // Try to acquire the bias of the object using an atomic operation.
  2202     // If this fails we will go in to the runtime to revoke the object's bias.
  2203     cas = new (C) StoreXConditionalNode(rebiased_region, mem, adr,
  2204                                            new_phi, old_phi);
  2205     transform_later(cas);
  2206     proj = transform_later( new (C) SCMemProjNode(cas));
  2208     // Get slow path - Failed to CAS.
  2209     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
  2210     mem_phi->init_req(4, proj);
  2211     // region->in(4) is set to fast path - the object is rebiased to the current thread.
  2213     // Failed to CAS.
  2214     slow_path  = new (C) RegionNode(3);
  2215     Node *slow_mem = new (C) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
  2217     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
  2218     slow_mem->init_req(1, proj);
  2220     // Call CAS-based locking scheme (FastLock node).
  2222     transform_later(fast_lock_region);
  2223     transform_later(fast_lock_mem_phi);
  2225     // Get slow path - FastLock failed to lock the object.
  2226     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
  2227     mem_phi->init_req(2, fast_lock_mem_phi);
  2228     // region->in(2) is set to fast path - the object is locked to the current thread.
  2230     slow_path->init_req(2, ctrl); // Capture slow-control
  2231     slow_mem->init_req(2, fast_lock_mem_phi);
  2233     transform_later(slow_path);
  2234     transform_later(slow_mem);
  2235     // Reset lock's memory edge.
  2236     lock->set_req(TypeFunc::Memory, slow_mem);
  2238   } else {
  2239     region  = new (C) RegionNode(3);
  2240     // create a Phi for the memory state
  2241     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2243     // Optimize test; set region slot 2
  2244     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
  2245     mem_phi->init_req(2, mem);
  2248   // Make slow path call
  2249   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
  2251   extract_call_projections(call);
  2253   // Slow path can only throw asynchronous exceptions, which are always
  2254   // de-opted.  So the compiler thinks the slow-call can never throw an
  2255   // exception.  If it DOES throw an exception we would need the debug
  2256   // info removed first (since if it throws there is no monitor).
  2257   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  2258            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  2260   // Capture slow path
  2261   // disconnect fall-through projection from call and create a new one
  2262   // hook up users of fall-through projection to region
  2263   Node *slow_ctrl = _fallthroughproj->clone();
  2264   transform_later(slow_ctrl);
  2265   _igvn.hash_delete(_fallthroughproj);
  2266   _fallthroughproj->disconnect_inputs(NULL, C);
  2267   region->init_req(1, slow_ctrl);
  2268   // region inputs are now complete
  2269   transform_later(region);
  2270   _igvn.replace_node(_fallthroughproj, region);
  2272   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
  2273   mem_phi->init_req(1, memproj );
  2274   transform_later(mem_phi);
  2275   _igvn.replace_node(_memproj_fallthrough, mem_phi);
  2278 //------------------------------expand_unlock_node----------------------
  2279 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
  2281   Node* ctrl = unlock->in(TypeFunc::Control);
  2282   Node* mem = unlock->in(TypeFunc::Memory);
  2283   Node* obj = unlock->obj_node();
  2284   Node* box = unlock->box_node();
  2286   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
  2288   // No need for a null check on unlock
  2290   // Make the merge point
  2291   Node *region;
  2292   Node *mem_phi;
  2294   if (UseOptoBiasInlining) {
  2295     // Check for biased locking unlock case, which is a no-op.
  2296     // See the full description in MacroAssembler::biased_locking_exit().
  2297     region  = new (C) RegionNode(4);
  2298     // create a Phi for the memory state
  2299     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2300     mem_phi->init_req(3, mem);
  2302     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  2303     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
  2304                          markOopDesc::biased_lock_mask_in_place,
  2305                          markOopDesc::biased_lock_pattern);
  2306   } else {
  2307     region  = new (C) RegionNode(3);
  2308     // create a Phi for the memory state
  2309     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2312   FastUnlockNode *funlock = new (C) FastUnlockNode( ctrl, obj, box );
  2313   funlock = transform_later( funlock )->as_FastUnlock();
  2314   // Optimize test; set region slot 2
  2315   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
  2317   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 );
  2319   extract_call_projections(call);
  2321   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  2322            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  2324   // No exceptions for unlocking
  2325   // Capture slow path
  2326   // disconnect fall-through projection from call and create a new one
  2327   // hook up users of fall-through projection to region
  2328   Node *slow_ctrl = _fallthroughproj->clone();
  2329   transform_later(slow_ctrl);
  2330   _igvn.hash_delete(_fallthroughproj);
  2331   _fallthroughproj->disconnect_inputs(NULL, C);
  2332   region->init_req(1, slow_ctrl);
  2333   // region inputs are now complete
  2334   transform_later(region);
  2335   _igvn.replace_node(_fallthroughproj, region);
  2337   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
  2338   mem_phi->init_req(1, memproj );
  2339   mem_phi->init_req(2, mem);
  2340   transform_later(mem_phi);
  2341   _igvn.replace_node(_memproj_fallthrough, mem_phi);
  2344 //---------------------------eliminate_macro_nodes----------------------
  2345 // Eliminate scalar replaced allocations and associated locks.
  2346 void PhaseMacroExpand::eliminate_macro_nodes() {
  2347   if (C->macro_count() == 0)
  2348     return;
  2350   // First, attempt to eliminate locks
  2351   int cnt = C->macro_count();
  2352   for (int i=0; i < cnt; i++) {
  2353     Node *n = C->macro_node(i);
  2354     if (n->is_AbstractLock()) { // Lock and Unlock nodes
  2355       // Before elimination mark all associated (same box and obj)
  2356       // lock and unlock nodes.
  2357       mark_eliminated_locking_nodes(n->as_AbstractLock());
  2360   bool progress = true;
  2361   while (progress) {
  2362     progress = false;
  2363     for (int i = C->macro_count(); i > 0; i--) {
  2364       Node * n = C->macro_node(i-1);
  2365       bool success = false;
  2366       debug_only(int old_macro_count = C->macro_count(););
  2367       if (n->is_AbstractLock()) {
  2368         success = eliminate_locking_node(n->as_AbstractLock());
  2370       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2371       progress = progress || success;
  2374   // Next, attempt to eliminate allocations
  2375   progress = true;
  2376   while (progress) {
  2377     progress = false;
  2378     for (int i = C->macro_count(); i > 0; i--) {
  2379       Node * n = C->macro_node(i-1);
  2380       bool success = false;
  2381       debug_only(int old_macro_count = C->macro_count(););
  2382       switch (n->class_id()) {
  2383       case Node::Class_Allocate:
  2384       case Node::Class_AllocateArray:
  2385         success = eliminate_allocate_node(n->as_Allocate());
  2386         break;
  2387       case Node::Class_Lock:
  2388       case Node::Class_Unlock:
  2389         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
  2390         break;
  2391       default:
  2392         assert(n->Opcode() == Op_LoopLimit ||
  2393                n->Opcode() == Op_Opaque1   ||
  2394                n->Opcode() == Op_Opaque2, "unknown node type in macro list");
  2396       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2397       progress = progress || success;
  2402 //------------------------------expand_macro_nodes----------------------
  2403 //  Returns true if a failure occurred.
  2404 bool PhaseMacroExpand::expand_macro_nodes() {
  2405   // Last attempt to eliminate macro nodes.
  2406   eliminate_macro_nodes();
  2408   // Make sure expansion will not cause node limit to be exceeded.
  2409   // Worst case is a macro node gets expanded into about 50 nodes.
  2410   // Allow 50% more for optimization.
  2411   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
  2412     return true;
  2414   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
  2415   bool progress = true;
  2416   while (progress) {
  2417     progress = false;
  2418     for (int i = C->macro_count(); i > 0; i--) {
  2419       Node * n = C->macro_node(i-1);
  2420       bool success = false;
  2421       debug_only(int old_macro_count = C->macro_count(););
  2422       if (n->Opcode() == Op_LoopLimit) {
  2423         // Remove it from macro list and put on IGVN worklist to optimize.
  2424         C->remove_macro_node(n);
  2425         _igvn._worklist.push(n);
  2426         success = true;
  2427       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
  2428         _igvn.replace_node(n, n->in(1));
  2429         success = true;
  2431       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2432       progress = progress || success;
  2436   // expand "macro" nodes
  2437   // nodes are removed from the macro list as they are processed
  2438   while (C->macro_count() > 0) {
  2439     int macro_count = C->macro_count();
  2440     Node * n = C->macro_node(macro_count-1);
  2441     assert(n->is_macro(), "only macro nodes expected here");
  2442     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
  2443       // node is unreachable, so don't try to expand it
  2444       C->remove_macro_node(n);
  2445       continue;
  2447     switch (n->class_id()) {
  2448     case Node::Class_Allocate:
  2449       expand_allocate(n->as_Allocate());
  2450       break;
  2451     case Node::Class_AllocateArray:
  2452       expand_allocate_array(n->as_AllocateArray());
  2453       break;
  2454     case Node::Class_Lock:
  2455       expand_lock_node(n->as_Lock());
  2456       break;
  2457     case Node::Class_Unlock:
  2458       expand_unlock_node(n->as_Unlock());
  2459       break;
  2460     default:
  2461       assert(false, "unknown node type in macro list");
  2463     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
  2464     if (C->failing())  return true;
  2467   _igvn.set_delay_transform(false);
  2468   _igvn.optimize();
  2469   if (C->failing())  return true;
  2470   return false;

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