src/share/vm/opto/macro.cpp

Fri, 07 Nov 2008 09:29:38 -0800

author
kvn
date
Fri, 07 Nov 2008 09:29:38 -0800
changeset 855
a1980da045cc
parent 797
f8199438385b
child 871
87559db65269
permissions
-rw-r--r--

6462850: generate biased locking code in C2 ideal graph
Summary: Inline biased locking code in C2 ideal graph during macro nodes expansion
Reviewed-by: never

     1 /*
     2  * Copyright 2005-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_macro.cpp.incl"
    29 //
    30 // Replace any references to "oldref" in inputs to "use" with "newref".
    31 // Returns the number of replacements made.
    32 //
    33 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
    34   int nreplacements = 0;
    35   uint req = use->req();
    36   for (uint j = 0; j < use->len(); j++) {
    37     Node *uin = use->in(j);
    38     if (uin == oldref) {
    39       if (j < req)
    40         use->set_req(j, newref);
    41       else
    42         use->set_prec(j, newref);
    43       nreplacements++;
    44     } else if (j >= req && uin == NULL) {
    45       break;
    46     }
    47   }
    48   return nreplacements;
    49 }
    51 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
    52   // Copy debug information and adjust JVMState information
    53   uint old_dbg_start = oldcall->tf()->domain()->cnt();
    54   uint new_dbg_start = newcall->tf()->domain()->cnt();
    55   int jvms_adj  = new_dbg_start - old_dbg_start;
    56   assert (new_dbg_start == newcall->req(), "argument count mismatch");
    58   Dict* sosn_map = new Dict(cmpkey,hashkey);
    59   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
    60     Node* old_in = oldcall->in(i);
    61     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
    62     if (old_in->is_SafePointScalarObject()) {
    63       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
    64       uint old_unique = C->unique();
    65       Node* new_in = old_sosn->clone(jvms_adj, sosn_map);
    66       if (old_unique != C->unique()) {
    67         new_in = transform_later(new_in); // Register new node.
    68       }
    69       old_in = new_in;
    70     }
    71     newcall->add_req(old_in);
    72   }
    74   newcall->set_jvms(oldcall->jvms());
    75   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
    76     jvms->set_map(newcall);
    77     jvms->set_locoff(jvms->locoff()+jvms_adj);
    78     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
    79     jvms->set_monoff(jvms->monoff()+jvms_adj);
    80     jvms->set_scloff(jvms->scloff()+jvms_adj);
    81     jvms->set_endoff(jvms->endoff()+jvms_adj);
    82   }
    83 }
    85 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
    86   Node* cmp;
    87   if (mask != 0) {
    88     Node* and_node = transform_later(new (C, 3) AndXNode(word, MakeConX(mask)));
    89     cmp = transform_later(new (C, 3) CmpXNode(and_node, MakeConX(bits)));
    90   } else {
    91     cmp = word;
    92   }
    93   Node* bol = transform_later(new (C, 2) BoolNode(cmp, BoolTest::ne));
    94   IfNode* iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
    95   transform_later(iff);
    97   // Fast path taken.
    98   Node *fast_taken = transform_later( new (C, 1) IfFalseNode(iff) );
   100   // Fast path not-taken, i.e. slow path
   101   Node *slow_taken = transform_later( new (C, 1) IfTrueNode(iff) );
   103   if (return_fast_path) {
   104     region->init_req(edge, slow_taken); // Capture slow-control
   105     return fast_taken;
   106   } else {
   107     region->init_req(edge, fast_taken); // Capture fast-control
   108     return slow_taken;
   109   }
   110 }
   112 //--------------------copy_predefined_input_for_runtime_call--------------------
   113 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
   114   // Set fixed predefined input arguments
   115   call->init_req( TypeFunc::Control, ctrl );
   116   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
   117   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
   118   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
   119   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
   120 }
   122 //------------------------------make_slow_call---------------------------------
   123 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) {
   125   // Slow-path call
   126   int size = slow_call_type->domain()->cnt();
   127  CallNode *call = leaf_name
   128    ? (CallNode*)new (C, size) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
   129    : (CallNode*)new (C, size) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
   131   // Slow path call has no side-effects, uses few values
   132   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
   133   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
   134   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
   135   copy_call_debug_info(oldcall, call);
   136   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
   137   _igvn.hash_delete(oldcall);
   138   _igvn.subsume_node(oldcall, call);
   139   transform_later(call);
   141   return call;
   142 }
   144 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
   145   _fallthroughproj = NULL;
   146   _fallthroughcatchproj = NULL;
   147   _ioproj_fallthrough = NULL;
   148   _ioproj_catchall = NULL;
   149   _catchallcatchproj = NULL;
   150   _memproj_fallthrough = NULL;
   151   _memproj_catchall = NULL;
   152   _resproj = NULL;
   153   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
   154     ProjNode *pn = call->fast_out(i)->as_Proj();
   155     switch (pn->_con) {
   156       case TypeFunc::Control:
   157       {
   158         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
   159         _fallthroughproj = pn;
   160         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
   161         const Node *cn = pn->fast_out(j);
   162         if (cn->is_Catch()) {
   163           ProjNode *cpn = NULL;
   164           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
   165             cpn = cn->fast_out(k)->as_Proj();
   166             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
   167             if (cpn->_con == CatchProjNode::fall_through_index)
   168               _fallthroughcatchproj = cpn;
   169             else {
   170               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
   171               _catchallcatchproj = cpn;
   172             }
   173           }
   174         }
   175         break;
   176       }
   177       case TypeFunc::I_O:
   178         if (pn->_is_io_use)
   179           _ioproj_catchall = pn;
   180         else
   181           _ioproj_fallthrough = pn;
   182         break;
   183       case TypeFunc::Memory:
   184         if (pn->_is_io_use)
   185           _memproj_catchall = pn;
   186         else
   187           _memproj_fallthrough = pn;
   188         break;
   189       case TypeFunc::Parms:
   190         _resproj = pn;
   191         break;
   192       default:
   193         assert(false, "unexpected projection from allocation node.");
   194     }
   195   }
   197 }
   199 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
   200 void PhaseMacroExpand::eliminate_card_mark(Node *p2x) {
   201   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
   202   Node *shift = p2x->unique_out();
   203   Node *addp = shift->unique_out();
   204   for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
   205     Node *st = addp->last_out(j);
   206     assert(st->is_Store(), "store required");
   207     _igvn.replace_node(st, st->in(MemNode::Memory));
   208   }
   209 }
   211 // Search for a memory operation for the specified memory slice.
   212 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
   213   Node *orig_mem = mem;
   214   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   215   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
   216   while (true) {
   217     if (mem == alloc_mem || mem == start_mem ) {
   218       return mem;  // hit one of our sentinals
   219     } else if (mem->is_MergeMem()) {
   220       mem = mem->as_MergeMem()->memory_at(alias_idx);
   221     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
   222       Node *in = mem->in(0);
   223       // we can safely skip over safepoints, calls, locks and membars because we
   224       // already know that the object is safe to eliminate.
   225       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
   226         return in;
   227       } else if (in->is_Call()) {
   228         CallNode *call = in->as_Call();
   229         if (!call->may_modify(tinst, phase)) {
   230           mem = call->in(TypeFunc::Memory);
   231         }
   232         mem = in->in(TypeFunc::Memory);
   233       } else if (in->is_MemBar()) {
   234         mem = in->in(TypeFunc::Memory);
   235       } else {
   236         assert(false, "unexpected projection");
   237       }
   238     } else if (mem->is_Store()) {
   239       const TypePtr* atype = mem->as_Store()->adr_type();
   240       int adr_idx = Compile::current()->get_alias_index(atype);
   241       if (adr_idx == alias_idx) {
   242         assert(atype->isa_oopptr(), "address type must be oopptr");
   243         int adr_offset = atype->offset();
   244         uint adr_iid = atype->is_oopptr()->instance_id();
   245         // Array elements references have the same alias_idx
   246         // but different offset and different instance_id.
   247         if (adr_offset == offset && adr_iid == alloc->_idx)
   248           return mem;
   249       } else {
   250         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
   251       }
   252       mem = mem->in(MemNode::Memory);
   253     } else {
   254       return mem;
   255     }
   256     assert(mem != orig_mem, "dead memory loop");
   257   }
   258 }
   260 //
   261 // Given a Memory Phi, compute a value Phi containing the values from stores
   262 // on the input paths.
   263 // Note: this function is recursive, its depth is limied by the "level" argument
   264 // Returns the computed Phi, or NULL if it cannot compute it.
   265 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) {
   266   assert(mem->is_Phi(), "sanity");
   267   int alias_idx = C->get_alias_index(adr_t);
   268   int offset = adr_t->offset();
   269   int instance_id = adr_t->instance_id();
   271   // Check if an appropriate value phi already exists.
   272   Node* region = mem->in(0);
   273   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
   274     Node* phi = region->fast_out(k);
   275     if (phi->is_Phi() && phi != mem &&
   276         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
   277       return phi;
   278     }
   279   }
   280   // Check if an appropriate new value phi already exists.
   281   Node* new_phi = NULL;
   282   uint size = value_phis->size();
   283   for (uint i=0; i < size; i++) {
   284     if ( mem->_idx == value_phis->index_at(i) ) {
   285       return value_phis->node_at(i);
   286     }
   287   }
   289   if (level <= 0) {
   290     return NULL; // Give up: phi tree too deep
   291   }
   292   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   293   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   295   uint length = mem->req();
   296   GrowableArray <Node *> values(length, length, NULL);
   298   // create a new Phi for the value
   299   PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
   300   transform_later(phi);
   301   value_phis->push(phi, mem->_idx);
   303   for (uint j = 1; j < length; j++) {
   304     Node *in = mem->in(j);
   305     if (in == NULL || in->is_top()) {
   306       values.at_put(j, in);
   307     } else  {
   308       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
   309       if (val == start_mem || val == alloc_mem) {
   310         // hit a sentinel, return appropriate 0 value
   311         values.at_put(j, _igvn.zerocon(ft));
   312         continue;
   313       }
   314       if (val->is_Initialize()) {
   315         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   316       }
   317       if (val == NULL) {
   318         return NULL;  // can't find a value on this path
   319       }
   320       if (val == mem) {
   321         values.at_put(j, mem);
   322       } else if (val->is_Store()) {
   323         values.at_put(j, val->in(MemNode::ValueIn));
   324       } else if(val->is_Proj() && val->in(0) == alloc) {
   325         values.at_put(j, _igvn.zerocon(ft));
   326       } else if (val->is_Phi()) {
   327         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
   328         if (val == NULL) {
   329           return NULL;
   330         }
   331         values.at_put(j, val);
   332       } else {
   333         assert(false, "unknown node on this path");
   334         return NULL;  // unknown node on this path
   335       }
   336     }
   337   }
   338   // Set Phi's inputs
   339   for (uint j = 1; j < length; j++) {
   340     if (values.at(j) == mem) {
   341       phi->init_req(j, phi);
   342     } else {
   343       phi->init_req(j, values.at(j));
   344     }
   345   }
   346   return phi;
   347 }
   349 // Search the last value stored into the object's field.
   350 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
   351   assert(adr_t->is_known_instance_field(), "instance required");
   352   int instance_id = adr_t->instance_id();
   353   assert((uint)instance_id == alloc->_idx, "wrong allocation");
   355   int alias_idx = C->get_alias_index(adr_t);
   356   int offset = adr_t->offset();
   357   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   358   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
   359   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   360   Arena *a = Thread::current()->resource_area();
   361   VectorSet visited(a);
   364   bool done = sfpt_mem == alloc_mem;
   365   Node *mem = sfpt_mem;
   366   while (!done) {
   367     if (visited.test_set(mem->_idx)) {
   368       return NULL;  // found a loop, give up
   369     }
   370     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
   371     if (mem == start_mem || mem == alloc_mem) {
   372       done = true;  // hit a sentinel, return appropriate 0 value
   373     } else if (mem->is_Initialize()) {
   374       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   375       if (mem == NULL) {
   376         done = true; // Something go wrong.
   377       } else if (mem->is_Store()) {
   378         const TypePtr* atype = mem->as_Store()->adr_type();
   379         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
   380         done = true;
   381       }
   382     } else if (mem->is_Store()) {
   383       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
   384       assert(atype != NULL, "address type must be oopptr");
   385       assert(C->get_alias_index(atype) == alias_idx &&
   386              atype->is_known_instance_field() && atype->offset() == offset &&
   387              atype->instance_id() == instance_id, "store is correct memory slice");
   388       done = true;
   389     } else if (mem->is_Phi()) {
   390       // try to find a phi's unique input
   391       Node *unique_input = NULL;
   392       Node *top = C->top();
   393       for (uint i = 1; i < mem->req(); i++) {
   394         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
   395         if (n == NULL || n == top || n == mem) {
   396           continue;
   397         } else if (unique_input == NULL) {
   398           unique_input = n;
   399         } else if (unique_input != n) {
   400           unique_input = top;
   401           break;
   402         }
   403       }
   404       if (unique_input != NULL && unique_input != top) {
   405         mem = unique_input;
   406       } else {
   407         done = true;
   408       }
   409     } else {
   410       assert(false, "unexpected node");
   411     }
   412   }
   413   if (mem != NULL) {
   414     if (mem == start_mem || mem == alloc_mem) {
   415       // hit a sentinel, return appropriate 0 value
   416       return _igvn.zerocon(ft);
   417     } else if (mem->is_Store()) {
   418       return mem->in(MemNode::ValueIn);
   419     } else if (mem->is_Phi()) {
   420       // attempt to produce a Phi reflecting the values on the input paths of the Phi
   421       Node_Stack value_phis(a, 8);
   422       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
   423       if (phi != NULL) {
   424         return phi;
   425       } else {
   426         // Kill all new Phis
   427         while(value_phis.is_nonempty()) {
   428           Node* n = value_phis.node();
   429           _igvn.hash_delete(n);
   430           _igvn.subsume_node(n, C->top());
   431           value_phis.pop();
   432         }
   433       }
   434     }
   435   }
   436   // Something go wrong.
   437   return NULL;
   438 }
   440 // Check the possibility of scalar replacement.
   441 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   442   //  Scan the uses of the allocation to check for anything that would
   443   //  prevent us from eliminating it.
   444   NOT_PRODUCT( const char* fail_eliminate = NULL; )
   445   DEBUG_ONLY( Node* disq_node = NULL; )
   446   bool  can_eliminate = true;
   448   Node* res = alloc->result_cast();
   449   const TypeOopPtr* res_type = NULL;
   450   if (res == NULL) {
   451     // All users were eliminated.
   452   } else if (!res->is_CheckCastPP()) {
   453     alloc->_is_scalar_replaceable = false;  // don't try again
   454     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
   455     can_eliminate = false;
   456   } else {
   457     res_type = _igvn.type(res)->isa_oopptr();
   458     if (res_type == NULL) {
   459       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
   460       can_eliminate = false;
   461     } else if (res_type->isa_aryptr()) {
   462       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   463       if (length < 0) {
   464         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
   465         can_eliminate = false;
   466       }
   467     }
   468   }
   470   if (can_eliminate && res != NULL) {
   471     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
   472                                j < jmax && can_eliminate; j++) {
   473       Node* use = res->fast_out(j);
   475       if (use->is_AddP()) {
   476         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
   477         int offset = addp_type->offset();
   479         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
   480           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
   481           can_eliminate = false;
   482           break;
   483         }
   484         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
   485                                    k < kmax && can_eliminate; k++) {
   486           Node* n = use->fast_out(k);
   487           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
   488             DEBUG_ONLY(disq_node = n;)
   489             if (n->is_Load() || n->is_LoadStore()) {
   490               NOT_PRODUCT(fail_eliminate = "Field load";)
   491             } else {
   492               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
   493             }
   494             can_eliminate = false;
   495           }
   496         }
   497       } else if (use->is_SafePoint()) {
   498         SafePointNode* sfpt = use->as_SafePoint();
   499         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
   500           // Object is passed as argument.
   501           DEBUG_ONLY(disq_node = use;)
   502           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
   503           can_eliminate = false;
   504         }
   505         Node* sfptMem = sfpt->memory();
   506         if (sfptMem == NULL || sfptMem->is_top()) {
   507           DEBUG_ONLY(disq_node = use;)
   508           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
   509           can_eliminate = false;
   510         } else {
   511           safepoints.append_if_missing(sfpt);
   512         }
   513       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
   514         if (use->is_Phi()) {
   515           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
   516             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   517           } else {
   518             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
   519           }
   520           DEBUG_ONLY(disq_node = use;)
   521         } else {
   522           if (use->Opcode() == Op_Return) {
   523             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   524           }else {
   525             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
   526           }
   527           DEBUG_ONLY(disq_node = use;)
   528         }
   529         can_eliminate = false;
   530       }
   531     }
   532   }
   534 #ifndef PRODUCT
   535   if (PrintEliminateAllocations) {
   536     if (can_eliminate) {
   537       tty->print("Scalar ");
   538       if (res == NULL)
   539         alloc->dump();
   540       else
   541         res->dump();
   542     } else {
   543       tty->print("NotScalar (%s)", fail_eliminate);
   544       if (res == NULL)
   545         alloc->dump();
   546       else
   547         res->dump();
   548 #ifdef ASSERT
   549       if (disq_node != NULL) {
   550           tty->print("  >>>> ");
   551           disq_node->dump();
   552       }
   553 #endif /*ASSERT*/
   554     }
   555   }
   556 #endif
   557   return can_eliminate;
   558 }
   560 // Do scalar replacement.
   561 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   562   GrowableArray <SafePointNode *> safepoints_done;
   564   ciKlass* klass = NULL;
   565   ciInstanceKlass* iklass = NULL;
   566   int nfields = 0;
   567   int array_base;
   568   int element_size;
   569   BasicType basic_elem_type;
   570   ciType* elem_type;
   572   Node* res = alloc->result_cast();
   573   const TypeOopPtr* res_type = NULL;
   574   if (res != NULL) { // Could be NULL when there are no users
   575     res_type = _igvn.type(res)->isa_oopptr();
   576   }
   578   if (res != NULL) {
   579     klass = res_type->klass();
   580     if (res_type->isa_instptr()) {
   581       // find the fields of the class which will be needed for safepoint debug information
   582       assert(klass->is_instance_klass(), "must be an instance klass.");
   583       iklass = klass->as_instance_klass();
   584       nfields = iklass->nof_nonstatic_fields();
   585     } else {
   586       // find the array's elements which will be needed for safepoint debug information
   587       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   588       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
   589       elem_type = klass->as_array_klass()->element_type();
   590       basic_elem_type = elem_type->basic_type();
   591       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
   592       element_size = type2aelembytes(basic_elem_type);
   593     }
   594   }
   595   //
   596   // Process the safepoint uses
   597   //
   598   while (safepoints.length() > 0) {
   599     SafePointNode* sfpt = safepoints.pop();
   600     Node* mem = sfpt->memory();
   601     uint first_ind = sfpt->req();
   602     SafePointScalarObjectNode* sobj = new (C, 1) SafePointScalarObjectNode(res_type,
   603 #ifdef ASSERT
   604                                                  alloc,
   605 #endif
   606                                                  first_ind, nfields);
   607     sobj->init_req(0, sfpt->in(TypeFunc::Control));
   608     transform_later(sobj);
   610     // Scan object's fields adding an input to the safepoint for each field.
   611     for (int j = 0; j < nfields; j++) {
   612       intptr_t offset;
   613       ciField* field = NULL;
   614       if (iklass != NULL) {
   615         field = iklass->nonstatic_field_at(j);
   616         offset = field->offset();
   617         elem_type = field->type();
   618         basic_elem_type = field->layout_type();
   619       } else {
   620         offset = array_base + j * (intptr_t)element_size;
   621       }
   623       const Type *field_type;
   624       // The next code is taken from Parse::do_get_xxx().
   625       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
   626         if (!elem_type->is_loaded()) {
   627           field_type = TypeInstPtr::BOTTOM;
   628         } else if (field != NULL && field->is_constant()) {
   629           // This can happen if the constant oop is non-perm.
   630           ciObject* con = field->constant_value().as_object();
   631           // Do not "join" in the previous type; it doesn't add value,
   632           // and may yield a vacuous result if the field is of interface type.
   633           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
   634           assert(field_type != NULL, "field singleton type must be consistent");
   635         } else {
   636           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
   637         }
   638         if (UseCompressedOops) {
   639           field_type = field_type->make_narrowoop();
   640           basic_elem_type = T_NARROWOOP;
   641         }
   642       } else {
   643         field_type = Type::get_const_basic_type(basic_elem_type);
   644       }
   646       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
   648       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
   649       if (field_val == NULL) {
   650         // we weren't able to find a value for this field,
   651         // give up on eliminating this allocation
   652         alloc->_is_scalar_replaceable = false;  // don't try again
   653         // remove any extra entries we added to the safepoint
   654         uint last = sfpt->req() - 1;
   655         for (int k = 0;  k < j; k++) {
   656           sfpt->del_req(last--);
   657         }
   658         // rollback processed safepoints
   659         while (safepoints_done.length() > 0) {
   660           SafePointNode* sfpt_done = safepoints_done.pop();
   661           // remove any extra entries we added to the safepoint
   662           last = sfpt_done->req() - 1;
   663           for (int k = 0;  k < nfields; k++) {
   664             sfpt_done->del_req(last--);
   665           }
   666           JVMState *jvms = sfpt_done->jvms();
   667           jvms->set_endoff(sfpt_done->req());
   668           // Now make a pass over the debug information replacing any references
   669           // to SafePointScalarObjectNode with the allocated object.
   670           int start = jvms->debug_start();
   671           int end   = jvms->debug_end();
   672           for (int i = start; i < end; i++) {
   673             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
   674               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
   675               if (scobj->first_index() == sfpt_done->req() &&
   676                   scobj->n_fields() == (uint)nfields) {
   677                 assert(scobj->alloc() == alloc, "sanity");
   678                 sfpt_done->set_req(i, res);
   679               }
   680             }
   681           }
   682         }
   683 #ifndef PRODUCT
   684         if (PrintEliminateAllocations) {
   685           if (field != NULL) {
   686             tty->print("=== At SafePoint node %d can't find value of Field: ",
   687                        sfpt->_idx);
   688             field->print();
   689             int field_idx = C->get_alias_index(field_addr_type);
   690             tty->print(" (alias_idx=%d)", field_idx);
   691           } else { // Array's element
   692             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
   693                        sfpt->_idx, j);
   694           }
   695           tty->print(", which prevents elimination of: ");
   696           if (res == NULL)
   697             alloc->dump();
   698           else
   699             res->dump();
   700         }
   701 #endif
   702         return false;
   703       }
   704       if (UseCompressedOops && field_type->isa_narrowoop()) {
   705         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
   706         // to be able scalar replace the allocation.
   707         if (field_val->is_EncodeP()) {
   708           field_val = field_val->in(1);
   709         } else {
   710           field_val = transform_later(new (C, 2) DecodeNNode(field_val, field_val->bottom_type()->make_ptr()));
   711         }
   712       }
   713       sfpt->add_req(field_val);
   714     }
   715     JVMState *jvms = sfpt->jvms();
   716     jvms->set_endoff(sfpt->req());
   717     // Now make a pass over the debug information replacing any references
   718     // to the allocated object with "sobj"
   719     int start = jvms->debug_start();
   720     int end   = jvms->debug_end();
   721     for (int i = start; i < end; i++) {
   722       if (sfpt->in(i) == res) {
   723         sfpt->set_req(i, sobj);
   724       }
   725     }
   726     safepoints_done.append_if_missing(sfpt); // keep it for rollback
   727   }
   728   return true;
   729 }
   731 // Process users of eliminated allocation.
   732 void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
   733   Node* res = alloc->result_cast();
   734   if (res != NULL) {
   735     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
   736       Node *use = res->last_out(j);
   737       uint oc1 = res->outcnt();
   739       if (use->is_AddP()) {
   740         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
   741           Node *n = use->last_out(k);
   742           uint oc2 = use->outcnt();
   743           if (n->is_Store()) {
   744             _igvn.replace_node(n, n->in(MemNode::Memory));
   745           } else {
   746             assert( n->Opcode() == Op_CastP2X, "CastP2X required");
   747             eliminate_card_mark(n);
   748           }
   749           k -= (oc2 - use->outcnt());
   750         }
   751       } else {
   752         assert( !use->is_SafePoint(), "safepoint uses must have been already elimiated");
   753         assert( use->Opcode() == Op_CastP2X, "CastP2X required");
   754         eliminate_card_mark(use);
   755       }
   756       j -= (oc1 - res->outcnt());
   757     }
   758     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
   759     _igvn.remove_dead_node(res);
   760   }
   762   //
   763   // Process other users of allocation's projections
   764   //
   765   if (_resproj != NULL && _resproj->outcnt() != 0) {
   766     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
   767       Node *use = _resproj->last_out(j);
   768       uint oc1 = _resproj->outcnt();
   769       if (use->is_Initialize()) {
   770         // Eliminate Initialize node.
   771         InitializeNode *init = use->as_Initialize();
   772         assert(init->outcnt() <= 2, "only a control and memory projection expected");
   773         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
   774         if (ctrl_proj != NULL) {
   775            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
   776           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
   777         }
   778         Node *mem_proj = init->proj_out(TypeFunc::Memory);
   779         if (mem_proj != NULL) {
   780           Node *mem = init->in(TypeFunc::Memory);
   781 #ifdef ASSERT
   782           if (mem->is_MergeMem()) {
   783             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
   784           } else {
   785             assert(mem == _memproj_fallthrough, "allocation memory projection");
   786           }
   787 #endif
   788           _igvn.replace_node(mem_proj, mem);
   789         }
   790       } else if (use->is_AddP()) {
   791         // raw memory addresses used only by the initialization
   792         _igvn.hash_delete(use);
   793         _igvn.subsume_node(use, C->top());
   794       } else  {
   795         assert(false, "only Initialize or AddP expected");
   796       }
   797       j -= (oc1 - _resproj->outcnt());
   798     }
   799   }
   800   if (_fallthroughcatchproj != NULL) {
   801     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
   802   }
   803   if (_memproj_fallthrough != NULL) {
   804     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
   805   }
   806   if (_memproj_catchall != NULL) {
   807     _igvn.replace_node(_memproj_catchall, C->top());
   808   }
   809   if (_ioproj_fallthrough != NULL) {
   810     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
   811   }
   812   if (_ioproj_catchall != NULL) {
   813     _igvn.replace_node(_ioproj_catchall, C->top());
   814   }
   815   if (_catchallcatchproj != NULL) {
   816     _igvn.replace_node(_catchallcatchproj, C->top());
   817   }
   818 }
   820 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
   822   if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {
   823     return false;
   824   }
   826   extract_call_projections(alloc);
   828   GrowableArray <SafePointNode *> safepoints;
   829   if (!can_eliminate_allocation(alloc, safepoints)) {
   830     return false;
   831   }
   833   if (!scalar_replacement(alloc, safepoints)) {
   834     return false;
   835   }
   837   process_users_of_allocation(alloc);
   839 #ifndef PRODUCT
   840 if (PrintEliminateAllocations) {
   841   if (alloc->is_AllocateArray())
   842     tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
   843   else
   844     tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
   845 }
   846 #endif
   848   return true;
   849 }
   852 //---------------------------set_eden_pointers-------------------------
   853 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
   854   if (UseTLAB) {                // Private allocation: load from TLS
   855     Node* thread = transform_later(new (C, 1) ThreadLocalNode());
   856     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
   857     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
   858     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
   859     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
   860   } else {                      // Shared allocation: load from globals
   861     CollectedHeap* ch = Universe::heap();
   862     address top_adr = (address)ch->top_addr();
   863     address end_adr = (address)ch->end_addr();
   864     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
   865     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
   866   }
   867 }
   870 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
   871   Node* adr = basic_plus_adr(base, offset);
   872   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
   873   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
   874   transform_later(value);
   875   return value;
   876 }
   879 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
   880   Node* adr = basic_plus_adr(base, offset);
   881   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
   882   transform_later(mem);
   883   return mem;
   884 }
   886 //=============================================================================
   887 //
   888 //                              A L L O C A T I O N
   889 //
   890 // Allocation attempts to be fast in the case of frequent small objects.
   891 // It breaks down like this:
   892 //
   893 // 1) Size in doublewords is computed.  This is a constant for objects and
   894 // variable for most arrays.  Doubleword units are used to avoid size
   895 // overflow of huge doubleword arrays.  We need doublewords in the end for
   896 // rounding.
   897 //
   898 // 2) Size is checked for being 'too large'.  Too-large allocations will go
   899 // the slow path into the VM.  The slow path can throw any required
   900 // exceptions, and does all the special checks for very large arrays.  The
   901 // size test can constant-fold away for objects.  For objects with
   902 // finalizers it constant-folds the otherway: you always go slow with
   903 // finalizers.
   904 //
   905 // 3) If NOT using TLABs, this is the contended loop-back point.
   906 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
   907 //
   908 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
   909 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
   910 // "size*8" we always enter the VM, where "largish" is a constant picked small
   911 // enough that there's always space between the eden max and 4Gig (old space is
   912 // there so it's quite large) and large enough that the cost of entering the VM
   913 // is dwarfed by the cost to initialize the space.
   914 //
   915 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
   916 // down.  If contended, repeat at step 3.  If using TLABs normal-store
   917 // adjusted heap top back down; there is no contention.
   918 //
   919 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
   920 // fields.
   921 //
   922 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
   923 // oop flavor.
   924 //
   925 //=============================================================================
   926 // FastAllocateSizeLimit value is in DOUBLEWORDS.
   927 // Allocations bigger than this always go the slow route.
   928 // This value must be small enough that allocation attempts that need to
   929 // trigger exceptions go the slow route.  Also, it must be small enough so
   930 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
   931 //=============================================================================j//
   932 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
   933 // The allocator will coalesce int->oop copies away.  See comment in
   934 // coalesce.cpp about how this works.  It depends critically on the exact
   935 // code shape produced here, so if you are changing this code shape
   936 // make sure the GC info for the heap-top is correct in and around the
   937 // slow-path call.
   938 //
   940 void PhaseMacroExpand::expand_allocate_common(
   941             AllocateNode* alloc, // allocation node to be expanded
   942             Node* length,  // array length for an array allocation
   943             const TypeFunc* slow_call_type, // Type of slow call
   944             address slow_call_address  // Address of slow call
   945     )
   946 {
   948   Node* ctrl = alloc->in(TypeFunc::Control);
   949   Node* mem  = alloc->in(TypeFunc::Memory);
   950   Node* i_o  = alloc->in(TypeFunc::I_O);
   951   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
   952   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
   953   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
   955   // With escape analysis, the entire memory state was needed to be able to
   956   // eliminate the allocation.  Since the allocations cannot be eliminated,
   957   // optimize it to the raw slice.
   958   if (mem->is_MergeMem()) {
   959     mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
   960   }
   962   assert(ctrl != NULL, "must have control");
   963   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
   964   // they will not be used if "always_slow" is set
   965   enum { slow_result_path = 1, fast_result_path = 2 };
   966   Node *result_region;
   967   Node *result_phi_rawmem;
   968   Node *result_phi_rawoop;
   969   Node *result_phi_i_o;
   971   // The initial slow comparison is a size check, the comparison
   972   // we want to do is a BoolTest::gt
   973   bool always_slow = false;
   974   int tv = _igvn.find_int_con(initial_slow_test, -1);
   975   if (tv >= 0) {
   976     always_slow = (tv == 1);
   977     initial_slow_test = NULL;
   978   } else {
   979     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
   980   }
   982   if (DTraceAllocProbes ||
   983       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
   984                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
   985     // Force slow-path allocation
   986     always_slow = true;
   987     initial_slow_test = NULL;
   988   }
   991   enum { too_big_or_final_path = 1, need_gc_path = 2 };
   992   Node *slow_region = NULL;
   993   Node *toobig_false = ctrl;
   995   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
   996   // generate the initial test if necessary
   997   if (initial_slow_test != NULL ) {
   998     slow_region = new (C, 3) RegionNode(3);
  1000     // Now make the initial failure test.  Usually a too-big test but
  1001     // might be a TRUE for finalizers or a fancy class check for
  1002     // newInstance0.
  1003     IfNode *toobig_iff = new (C, 2) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
  1004     transform_later(toobig_iff);
  1005     // Plug the failing-too-big test into the slow-path region
  1006     Node *toobig_true = new (C, 1) IfTrueNode( toobig_iff );
  1007     transform_later(toobig_true);
  1008     slow_region    ->init_req( too_big_or_final_path, toobig_true );
  1009     toobig_false = new (C, 1) IfFalseNode( toobig_iff );
  1010     transform_later(toobig_false);
  1011   } else {         // No initial test, just fall into next case
  1012     toobig_false = ctrl;
  1013     debug_only(slow_region = NodeSentinel);
  1016   Node *slow_mem = mem;  // save the current memory state for slow path
  1017   // generate the fast allocation code unless we know that the initial test will always go slow
  1018   if (!always_slow) {
  1019     Node* eden_top_adr;
  1020     Node* eden_end_adr;
  1022     set_eden_pointers(eden_top_adr, eden_end_adr);
  1024     // Load Eden::end.  Loop invariant and hoisted.
  1025     //
  1026     // Note: We set the control input on "eden_end" and "old_eden_top" when using
  1027     //       a TLAB to work around a bug where these values were being moved across
  1028     //       a safepoint.  These are not oops, so they cannot be include in the oop
  1029     //       map, but the can be changed by a GC.   The proper way to fix this would
  1030     //       be to set the raw memory state when generating a  SafepointNode.  However
  1031     //       this will require extensive changes to the loop optimization in order to
  1032     //       prevent a degradation of the optimization.
  1033     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
  1034     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
  1036     // allocate the Region and Phi nodes for the result
  1037     result_region = new (C, 3) RegionNode(3);
  1038     result_phi_rawmem = new (C, 3) PhiNode( result_region, Type::MEMORY, TypeRawPtr::BOTTOM );
  1039     result_phi_rawoop = new (C, 3) PhiNode( result_region, TypeRawPtr::BOTTOM );
  1040     result_phi_i_o    = new (C, 3) PhiNode( result_region, Type::ABIO ); // I/O is used for Prefetch
  1042     // We need a Region for the loop-back contended case.
  1043     enum { fall_in_path = 1, contended_loopback_path = 2 };
  1044     Node *contended_region;
  1045     Node *contended_phi_rawmem;
  1046     if( UseTLAB ) {
  1047       contended_region = toobig_false;
  1048       contended_phi_rawmem = mem;
  1049     } else {
  1050       contended_region = new (C, 3) RegionNode(3);
  1051       contended_phi_rawmem = new (C, 3) PhiNode( contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1052       // Now handle the passing-too-big test.  We fall into the contended
  1053       // loop-back merge point.
  1054       contended_region    ->init_req( fall_in_path, toobig_false );
  1055       contended_phi_rawmem->init_req( fall_in_path, mem );
  1056       transform_later(contended_region);
  1057       transform_later(contended_phi_rawmem);
  1060     // Load(-locked) the heap top.
  1061     // See note above concerning the control input when using a TLAB
  1062     Node *old_eden_top = UseTLAB
  1063       ? new (C, 3) LoadPNode     ( ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM )
  1064       : new (C, 3) LoadPLockedNode( contended_region, contended_phi_rawmem, eden_top_adr );
  1066     transform_later(old_eden_top);
  1067     // Add to heap top to get a new heap top
  1068     Node *new_eden_top = new (C, 4) AddPNode( top(), old_eden_top, size_in_bytes );
  1069     transform_later(new_eden_top);
  1070     // Check for needing a GC; compare against heap end
  1071     Node *needgc_cmp = new (C, 3) CmpPNode( new_eden_top, eden_end );
  1072     transform_later(needgc_cmp);
  1073     Node *needgc_bol = new (C, 2) BoolNode( needgc_cmp, BoolTest::ge );
  1074     transform_later(needgc_bol);
  1075     IfNode *needgc_iff = new (C, 2) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
  1076     transform_later(needgc_iff);
  1078     // Plug the failing-heap-space-need-gc test into the slow-path region
  1079     Node *needgc_true = new (C, 1) IfTrueNode( needgc_iff );
  1080     transform_later(needgc_true);
  1081     if( initial_slow_test ) {
  1082       slow_region    ->init_req( need_gc_path, needgc_true );
  1083       // This completes all paths into the slow merge point
  1084       transform_later(slow_region);
  1085     } else {                      // No initial slow path needed!
  1086       // Just fall from the need-GC path straight into the VM call.
  1087       slow_region    = needgc_true;
  1089     // No need for a GC.  Setup for the Store-Conditional
  1090     Node *needgc_false = new (C, 1) IfFalseNode( needgc_iff );
  1091     transform_later(needgc_false);
  1093     // Grab regular I/O before optional prefetch may change it.
  1094     // Slow-path does no I/O so just set it to the original I/O.
  1095     result_phi_i_o->init_req( slow_result_path, i_o );
  1097     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
  1098                               old_eden_top, new_eden_top, length);
  1100     // Store (-conditional) the modified eden top back down.
  1101     // StorePConditional produces flags for a test PLUS a modified raw
  1102     // memory state.
  1103     Node *store_eden_top;
  1104     Node *fast_oop_ctrl;
  1105     if( UseTLAB ) {
  1106       store_eden_top = new (C, 4) StorePNode( needgc_false, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, new_eden_top );
  1107       transform_later(store_eden_top);
  1108       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
  1109     } else {
  1110       store_eden_top = new (C, 5) StorePConditionalNode( needgc_false, contended_phi_rawmem, eden_top_adr, new_eden_top, old_eden_top );
  1111       transform_later(store_eden_top);
  1112       Node *contention_check = new (C, 2) BoolNode( store_eden_top, BoolTest::ne );
  1113       transform_later(contention_check);
  1114       store_eden_top = new (C, 1) SCMemProjNode(store_eden_top);
  1115       transform_later(store_eden_top);
  1117       // If not using TLABs, check to see if there was contention.
  1118       IfNode *contention_iff = new (C, 2) IfNode ( needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN );
  1119       transform_later(contention_iff);
  1120       Node *contention_true = new (C, 1) IfTrueNode( contention_iff );
  1121       transform_later(contention_true);
  1122       // If contention, loopback and try again.
  1123       contended_region->init_req( contended_loopback_path, contention_true );
  1124       contended_phi_rawmem->init_req( contended_loopback_path, store_eden_top );
  1126       // Fast-path succeeded with no contention!
  1127       Node *contention_false = new (C, 1) IfFalseNode( contention_iff );
  1128       transform_later(contention_false);
  1129       fast_oop_ctrl = contention_false;
  1132     // Rename successful fast-path variables to make meaning more obvious
  1133     Node* fast_oop        = old_eden_top;
  1134     Node* fast_oop_rawmem = store_eden_top;
  1135     fast_oop_rawmem = initialize_object(alloc,
  1136                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
  1137                                         klass_node, length, size_in_bytes);
  1139     if (ExtendedDTraceProbes) {
  1140       // Slow-path call
  1141       int size = TypeFunc::Parms + 2;
  1142       CallLeafNode *call = new (C, size) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
  1143                                                       CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
  1144                                                       "dtrace_object_alloc",
  1145                                                       TypeRawPtr::BOTTOM);
  1147       // Get base of thread-local storage area
  1148       Node* thread = new (C, 1) ThreadLocalNode();
  1149       transform_later(thread);
  1151       call->init_req(TypeFunc::Parms+0, thread);
  1152       call->init_req(TypeFunc::Parms+1, fast_oop);
  1153       call->init_req( TypeFunc::Control, fast_oop_ctrl );
  1154       call->init_req( TypeFunc::I_O    , top() )        ;   // does no i/o
  1155       call->init_req( TypeFunc::Memory , fast_oop_rawmem );
  1156       call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
  1157       call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
  1158       transform_later(call);
  1159       fast_oop_ctrl = new (C, 1) ProjNode(call,TypeFunc::Control);
  1160       transform_later(fast_oop_ctrl);
  1161       fast_oop_rawmem = new (C, 1) ProjNode(call,TypeFunc::Memory);
  1162       transform_later(fast_oop_rawmem);
  1165     // Plug in the successful fast-path into the result merge point
  1166     result_region    ->init_req( fast_result_path, fast_oop_ctrl );
  1167     result_phi_rawoop->init_req( fast_result_path, fast_oop );
  1168     result_phi_i_o   ->init_req( fast_result_path, i_o );
  1169     result_phi_rawmem->init_req( fast_result_path, fast_oop_rawmem );
  1170   } else {
  1171     slow_region = ctrl;
  1174   // Generate slow-path call
  1175   CallNode *call = new (C, slow_call_type->domain()->cnt())
  1176     CallStaticJavaNode(slow_call_type, slow_call_address,
  1177                        OptoRuntime::stub_name(slow_call_address),
  1178                        alloc->jvms()->bci(),
  1179                        TypePtr::BOTTOM);
  1180   call->init_req( TypeFunc::Control, slow_region );
  1181   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
  1182   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
  1183   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
  1184   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
  1186   call->init_req(TypeFunc::Parms+0, klass_node);
  1187   if (length != NULL) {
  1188     call->init_req(TypeFunc::Parms+1, length);
  1191   // Copy debug information and adjust JVMState information, then replace
  1192   // allocate node with the call
  1193   copy_call_debug_info((CallNode *) alloc,  call);
  1194   if (!always_slow) {
  1195     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
  1197   _igvn.hash_delete(alloc);
  1198   _igvn.subsume_node(alloc, call);
  1199   transform_later(call);
  1201   // Identify the output projections from the allocate node and
  1202   // adjust any references to them.
  1203   // The control and io projections look like:
  1204   //
  1205   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
  1206   //  Allocate                   Catch
  1207   //        ^---Proj(io) <-------+   ^---CatchProj(io)
  1208   //
  1209   //  We are interested in the CatchProj nodes.
  1210   //
  1211   extract_call_projections(call);
  1213   // An allocate node has separate memory projections for the uses on the control and i_o paths
  1214   // Replace uses of the control memory projection with result_phi_rawmem (unless we are only generating a slow call)
  1215   if (!always_slow && _memproj_fallthrough != NULL) {
  1216     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1217       Node *use = _memproj_fallthrough->fast_out(i);
  1218       _igvn.hash_delete(use);
  1219       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
  1220       _igvn._worklist.push(use);
  1221       // back up iterator
  1222       --i;
  1225   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete _memproj_catchall so
  1226   // we end up with a call that has only 1 memory projection
  1227   if (_memproj_catchall != NULL ) {
  1228     if (_memproj_fallthrough == NULL) {
  1229       _memproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::Memory);
  1230       transform_later(_memproj_fallthrough);
  1232     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
  1233       Node *use = _memproj_catchall->fast_out(i);
  1234       _igvn.hash_delete(use);
  1235       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
  1236       _igvn._worklist.push(use);
  1237       // back up iterator
  1238       --i;
  1242   mem = result_phi_rawmem;
  1244   // An allocate node has separate i_o projections for the uses on the control and i_o paths
  1245   // Replace uses of the control i_o projection with result_phi_i_o (unless we are only generating a slow call)
  1246   if (_ioproj_fallthrough == NULL) {
  1247     _ioproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::I_O);
  1248     transform_later(_ioproj_fallthrough);
  1249   } else if (!always_slow) {
  1250     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1251       Node *use = _ioproj_fallthrough->fast_out(i);
  1253       _igvn.hash_delete(use);
  1254       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
  1255       _igvn._worklist.push(use);
  1256       // back up iterator
  1257       --i;
  1260   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete _ioproj_catchall so
  1261   // we end up with a call that has only 1 control projection
  1262   if (_ioproj_catchall != NULL ) {
  1263     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
  1264       Node *use = _ioproj_catchall->fast_out(i);
  1265       _igvn.hash_delete(use);
  1266       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
  1267       _igvn._worklist.push(use);
  1268       // back up iterator
  1269       --i;
  1273   // if we generated only a slow call, we are done
  1274   if (always_slow)
  1275     return;
  1278   if (_fallthroughcatchproj != NULL) {
  1279     ctrl = _fallthroughcatchproj->clone();
  1280     transform_later(ctrl);
  1281     _igvn.hash_delete(_fallthroughcatchproj);
  1282     _igvn.subsume_node(_fallthroughcatchproj, result_region);
  1283   } else {
  1284     ctrl = top();
  1286   Node *slow_result;
  1287   if (_resproj == NULL) {
  1288     // no uses of the allocation result
  1289     slow_result = top();
  1290   } else {
  1291     slow_result = _resproj->clone();
  1292     transform_later(slow_result);
  1293     _igvn.hash_delete(_resproj);
  1294     _igvn.subsume_node(_resproj, result_phi_rawoop);
  1297   // Plug slow-path into result merge point
  1298   result_region    ->init_req( slow_result_path, ctrl );
  1299   result_phi_rawoop->init_req( slow_result_path, slow_result);
  1300   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
  1301   transform_later(result_region);
  1302   transform_later(result_phi_rawoop);
  1303   transform_later(result_phi_rawmem);
  1304   transform_later(result_phi_i_o);
  1305   // This completes all paths into the result merge point
  1309 // Helper for PhaseMacroExpand::expand_allocate_common.
  1310 // Initializes the newly-allocated storage.
  1311 Node*
  1312 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
  1313                                     Node* control, Node* rawmem, Node* object,
  1314                                     Node* klass_node, Node* length,
  1315                                     Node* size_in_bytes) {
  1316   InitializeNode* init = alloc->initialization();
  1317   // Store the klass & mark bits
  1318   Node* mark_node = NULL;
  1319   // For now only enable fast locking for non-array types
  1320   if (UseBiasedLocking && (length == NULL)) {
  1321     mark_node = make_load(NULL, rawmem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeRawPtr::BOTTOM, T_ADDRESS);
  1322   } else {
  1323     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
  1325   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
  1327   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_OBJECT);
  1328   int header_size = alloc->minimum_header_size();  // conservatively small
  1330   // Array length
  1331   if (length != NULL) {         // Arrays need length field
  1332     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
  1333     // conservatively small header size:
  1334     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1335     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1336     if (k->is_array_klass())    // we know the exact header size in most cases:
  1337       header_size = Klass::layout_helper_header_size(k->layout_helper());
  1340   // Clear the object body, if necessary.
  1341   if (init == NULL) {
  1342     // The init has somehow disappeared; be cautious and clear everything.
  1343     //
  1344     // This can happen if a node is allocated but an uncommon trap occurs
  1345     // immediately.  In this case, the Initialize gets associated with the
  1346     // trap, and may be placed in a different (outer) loop, if the Allocate
  1347     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
  1348     // there can be two Allocates to one Initialize.  The answer in all these
  1349     // edge cases is safety first.  It is always safe to clear immediately
  1350     // within an Allocate, and then (maybe or maybe not) clear some more later.
  1351     if (!ZeroTLAB)
  1352       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
  1353                                             header_size, size_in_bytes,
  1354                                             &_igvn);
  1355   } else {
  1356     if (!init->is_complete()) {
  1357       // Try to win by zeroing only what the init does not store.
  1358       // We can also try to do some peephole optimizations,
  1359       // such as combining some adjacent subword stores.
  1360       rawmem = init->complete_stores(control, rawmem, object,
  1361                                      header_size, size_in_bytes, &_igvn);
  1363     // We have no more use for this link, since the AllocateNode goes away:
  1364     init->set_req(InitializeNode::RawAddress, top());
  1365     // (If we keep the link, it just confuses the register allocator,
  1366     // who thinks he sees a real use of the address by the membar.)
  1369   return rawmem;
  1372 // Generate prefetch instructions for next allocations.
  1373 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
  1374                                         Node*& contended_phi_rawmem,
  1375                                         Node* old_eden_top, Node* new_eden_top,
  1376                                         Node* length) {
  1377    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
  1378       // Generate prefetch allocation with watermark check.
  1379       // As an allocation hits the watermark, we will prefetch starting
  1380       // at a "distance" away from watermark.
  1381       enum { fall_in_path = 1, pf_path = 2 };
  1383       Node *pf_region = new (C, 3) RegionNode(3);
  1384       Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
  1385                                                 TypeRawPtr::BOTTOM );
  1386       // I/O is used for Prefetch
  1387       Node *pf_phi_abio = new (C, 3) PhiNode( pf_region, Type::ABIO );
  1389       Node *thread = new (C, 1) ThreadLocalNode();
  1390       transform_later(thread);
  1392       Node *eden_pf_adr = new (C, 4) AddPNode( top()/*not oop*/, thread,
  1393                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
  1394       transform_later(eden_pf_adr);
  1396       Node *old_pf_wm = new (C, 3) LoadPNode( needgc_false,
  1397                                    contended_phi_rawmem, eden_pf_adr,
  1398                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
  1399       transform_later(old_pf_wm);
  1401       // check against new_eden_top
  1402       Node *need_pf_cmp = new (C, 3) CmpPNode( new_eden_top, old_pf_wm );
  1403       transform_later(need_pf_cmp);
  1404       Node *need_pf_bol = new (C, 2) BoolNode( need_pf_cmp, BoolTest::ge );
  1405       transform_later(need_pf_bol);
  1406       IfNode *need_pf_iff = new (C, 2) IfNode( needgc_false, need_pf_bol,
  1407                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
  1408       transform_later(need_pf_iff);
  1410       // true node, add prefetchdistance
  1411       Node *need_pf_true = new (C, 1) IfTrueNode( need_pf_iff );
  1412       transform_later(need_pf_true);
  1414       Node *need_pf_false = new (C, 1) IfFalseNode( need_pf_iff );
  1415       transform_later(need_pf_false);
  1417       Node *new_pf_wmt = new (C, 4) AddPNode( top(), old_pf_wm,
  1418                                     _igvn.MakeConX(AllocatePrefetchDistance) );
  1419       transform_later(new_pf_wmt );
  1420       new_pf_wmt->set_req(0, need_pf_true);
  1422       Node *store_new_wmt = new (C, 4) StorePNode( need_pf_true,
  1423                                        contended_phi_rawmem, eden_pf_adr,
  1424                                        TypeRawPtr::BOTTOM, new_pf_wmt );
  1425       transform_later(store_new_wmt);
  1427       // adding prefetches
  1428       pf_phi_abio->init_req( fall_in_path, i_o );
  1430       Node *prefetch_adr;
  1431       Node *prefetch;
  1432       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
  1433       uint step_size = AllocatePrefetchStepSize;
  1434       uint distance = 0;
  1436       for ( uint i = 0; i < lines; i++ ) {
  1437         prefetch_adr = new (C, 4) AddPNode( old_pf_wm, new_pf_wmt,
  1438                                             _igvn.MakeConX(distance) );
  1439         transform_later(prefetch_adr);
  1440         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
  1441         transform_later(prefetch);
  1442         distance += step_size;
  1443         i_o = prefetch;
  1445       pf_phi_abio->set_req( pf_path, i_o );
  1447       pf_region->init_req( fall_in_path, need_pf_false );
  1448       pf_region->init_req( pf_path, need_pf_true );
  1450       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
  1451       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
  1453       transform_later(pf_region);
  1454       transform_later(pf_phi_rawmem);
  1455       transform_later(pf_phi_abio);
  1457       needgc_false = pf_region;
  1458       contended_phi_rawmem = pf_phi_rawmem;
  1459       i_o = pf_phi_abio;
  1460    } else if( AllocatePrefetchStyle > 0 ) {
  1461       // Insert a prefetch for each allocation only on the fast-path
  1462       Node *prefetch_adr;
  1463       Node *prefetch;
  1464       // Generate several prefetch instructions only for arrays.
  1465       uint lines = (length != NULL) ? AllocatePrefetchLines : 1;
  1466       uint step_size = AllocatePrefetchStepSize;
  1467       uint distance = AllocatePrefetchDistance;
  1468       for ( uint i = 0; i < lines; i++ ) {
  1469         prefetch_adr = new (C, 4) AddPNode( old_eden_top, new_eden_top,
  1470                                             _igvn.MakeConX(distance) );
  1471         transform_later(prefetch_adr);
  1472         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
  1473         // Do not let it float too high, since if eden_top == eden_end,
  1474         // both might be null.
  1475         if( i == 0 ) { // Set control for first prefetch, next follows it
  1476           prefetch->init_req(0, needgc_false);
  1478         transform_later(prefetch);
  1479         distance += step_size;
  1480         i_o = prefetch;
  1483    return i_o;
  1487 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
  1488   expand_allocate_common(alloc, NULL,
  1489                          OptoRuntime::new_instance_Type(),
  1490                          OptoRuntime::new_instance_Java());
  1493 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
  1494   Node* length = alloc->in(AllocateNode::ALength);
  1495   expand_allocate_common(alloc, length,
  1496                          OptoRuntime::new_array_Type(),
  1497                          OptoRuntime::new_array_Java());
  1501 // we have determined that this lock/unlock can be eliminated, we simply
  1502 // eliminate the node without expanding it.
  1503 //
  1504 // Note:  The membar's associated with the lock/unlock are currently not
  1505 //        eliminated.  This should be investigated as a future enhancement.
  1506 //
  1507 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
  1509   if (!alock->is_eliminated()) {
  1510     return false;
  1512   // Mark the box lock as eliminated if all correspondent locks are eliminated
  1513   // to construct correct debug info.
  1514   BoxLockNode* box = alock->box_node()->as_BoxLock();
  1515   if (!box->is_eliminated()) {
  1516     bool eliminate = true;
  1517     for (DUIterator_Fast imax, i = box->fast_outs(imax); i < imax; i++) {
  1518       Node *lck = box->fast_out(i);
  1519       if (lck->is_Lock() && !lck->as_AbstractLock()->is_eliminated()) {
  1520         eliminate = false;
  1521         break;
  1524     if (eliminate)
  1525       box->set_eliminated();
  1528   #ifndef PRODUCT
  1529   if (PrintEliminateLocks) {
  1530     if (alock->is_Lock()) {
  1531       tty->print_cr("++++ Eliminating: %d Lock", alock->_idx);
  1532     } else {
  1533       tty->print_cr("++++ Eliminating: %d Unlock", alock->_idx);
  1536   #endif
  1538   Node* mem  = alock->in(TypeFunc::Memory);
  1539   Node* ctrl = alock->in(TypeFunc::Control);
  1541   extract_call_projections(alock);
  1542   // There are 2 projections from the lock.  The lock node will
  1543   // be deleted when its last use is subsumed below.
  1544   assert(alock->outcnt() == 2 &&
  1545          _fallthroughproj != NULL &&
  1546          _memproj_fallthrough != NULL,
  1547          "Unexpected projections from Lock/Unlock");
  1549   Node* fallthroughproj = _fallthroughproj;
  1550   Node* memproj_fallthrough = _memproj_fallthrough;
  1552   // The memory projection from a lock/unlock is RawMem
  1553   // The input to a Lock is merged memory, so extract its RawMem input
  1554   // (unless the MergeMem has been optimized away.)
  1555   if (alock->is_Lock()) {
  1556     // Seach for MemBarAcquire node and delete it also.
  1557     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
  1558     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquire, "");
  1559     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
  1560     Node* memproj = membar->proj_out(TypeFunc::Memory);
  1561     _igvn.hash_delete(ctrlproj);
  1562     _igvn.subsume_node(ctrlproj, fallthroughproj);
  1563     _igvn.hash_delete(memproj);
  1564     _igvn.subsume_node(memproj, memproj_fallthrough);
  1567   // Seach for MemBarRelease node and delete it also.
  1568   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
  1569       ctrl->in(0)->is_MemBar()) {
  1570     MemBarNode* membar = ctrl->in(0)->as_MemBar();
  1571     assert(membar->Opcode() == Op_MemBarRelease &&
  1572            mem->is_Proj() && membar == mem->in(0), "");
  1573     _igvn.hash_delete(fallthroughproj);
  1574     _igvn.subsume_node(fallthroughproj, ctrl);
  1575     _igvn.hash_delete(memproj_fallthrough);
  1576     _igvn.subsume_node(memproj_fallthrough, mem);
  1577     fallthroughproj = ctrl;
  1578     memproj_fallthrough = mem;
  1579     ctrl = membar->in(TypeFunc::Control);
  1580     mem  = membar->in(TypeFunc::Memory);
  1583   _igvn.hash_delete(fallthroughproj);
  1584   _igvn.subsume_node(fallthroughproj, ctrl);
  1585   _igvn.hash_delete(memproj_fallthrough);
  1586   _igvn.subsume_node(memproj_fallthrough, mem);
  1587   return true;
  1591 //------------------------------expand_lock_node----------------------
  1592 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
  1594   Node* ctrl = lock->in(TypeFunc::Control);
  1595   Node* mem = lock->in(TypeFunc::Memory);
  1596   Node* obj = lock->obj_node();
  1597   Node* box = lock->box_node();
  1598   Node* flock = lock->fastlock_node();
  1600   // Make the merge point
  1601   Node *region;
  1602   Node *mem_phi;
  1603   Node *slow_path;
  1605   if (UseOptoBiasInlining) {
  1606     /*
  1607      *  See the full descrition in MacroAssembler::biased_locking_enter().
  1609      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
  1610      *    // The object is biased.
  1611      *    proto_node = klass->prototype_header;
  1612      *    o_node = thread | proto_node;
  1613      *    x_node = o_node ^ mark_word;
  1614      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
  1615      *      // Done.
  1616      *    } else {
  1617      *      if( (x_node & biased_lock_mask) != 0 ) {
  1618      *        // The klass's prototype header is no longer biased.
  1619      *        cas(&mark_word, mark_word, proto_node)
  1620      *        goto cas_lock;
  1621      *      } else {
  1622      *        // The klass's prototype header is still biased.
  1623      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
  1624      *          old = mark_word;
  1625      *          new = o_node;
  1626      *        } else {
  1627      *          // Different thread or anonymous biased.
  1628      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
  1629      *          new = thread | old;
  1630      *        }
  1631      *        // Try to rebias.
  1632      *        if( cas(&mark_word, old, new) == 0 ) {
  1633      *          // Done.
  1634      *        } else {
  1635      *          goto slow_path; // Failed.
  1636      *        }
  1637      *      }
  1638      *    }
  1639      *  } else {
  1640      *    // The object is not biased.
  1641      *    cas_lock:
  1642      *    if( FastLock(obj) == 0 ) {
  1643      *      // Done.
  1644      *    } else {
  1645      *      slow_path:
  1646      *      OptoRuntime::complete_monitor_locking_Java(obj);
  1647      *    }
  1648      *  }
  1649      */
  1651     region  = new (C, 5) RegionNode(5);
  1652     // create a Phi for the memory state
  1653     mem_phi = new (C, 5) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1655     Node* fast_lock_region  = new (C, 3) RegionNode(3);
  1656     Node* fast_lock_mem_phi = new (C, 3) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1658     // First, check mark word for the biased lock pattern.
  1659     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  1661     // Get fast path - mark word has the biased lock pattern.
  1662     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
  1663                          markOopDesc::biased_lock_mask_in_place,
  1664                          markOopDesc::biased_lock_pattern, true);
  1665     // fast_lock_region->in(1) is set to slow path.
  1666     fast_lock_mem_phi->init_req(1, mem);
  1668     // Now check that the lock is biased to the current thread and has
  1669     // the same epoch and bias as Klass::_prototype_header.
  1671     // Special-case a fresh allocation to avoid building nodes:
  1672     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
  1673     if (klass_node == NULL) {
  1674       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
  1675       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
  1676       klass_node->init_req(0, ctrl);
  1678     Node *proto_node = make_load(ctrl, mem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeX_X, TypeX_X->basic_type());
  1680     Node* thread = transform_later(new (C, 1) ThreadLocalNode());
  1681     Node* cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
  1682     Node* o_node = transform_later(new (C, 3) OrXNode(cast_thread, proto_node));
  1683     Node* x_node = transform_later(new (C, 3) XorXNode(o_node, mark_node));
  1685     // Get slow path - mark word does NOT match the value.
  1686     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
  1687                                       (~markOopDesc::age_mask_in_place), 0);
  1688     // region->in(3) is set to fast path - the object is biased to the current thread.
  1689     mem_phi->init_req(3, mem);
  1692     // Mark word does NOT match the value (thread | Klass::_prototype_header).
  1695     // First, check biased pattern.
  1696     // Get fast path - _prototype_header has the same biased lock pattern.
  1697     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
  1698                           markOopDesc::biased_lock_mask_in_place, 0, true);
  1700     not_biased_ctrl = fast_lock_region->in(2); // Slow path
  1701     // fast_lock_region->in(2) - the prototype header is no longer biased
  1702     // and we have to revoke the bias on this object.
  1703     // We are going to try to reset the mark of this object to the prototype
  1704     // value and fall through to the CAS-based locking scheme.
  1705     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
  1706     Node* cas = new (C, 5) StoreXConditionalNode(not_biased_ctrl, mem, adr,
  1707                                                  proto_node, mark_node);
  1708     transform_later(cas);
  1709     Node* proj = transform_later( new (C, 1) SCMemProjNode(cas));
  1710     fast_lock_mem_phi->init_req(2, proj);
  1713     // Second, check epoch bits.
  1714     Node* rebiased_region  = new (C, 3) RegionNode(3);
  1715     Node* old_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
  1716     Node* new_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
  1718     // Get slow path - mark word does NOT match epoch bits.
  1719     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
  1720                                       markOopDesc::epoch_mask_in_place, 0);
  1721     // The epoch of the current bias is not valid, attempt to rebias the object
  1722     // toward the current thread.
  1723     rebiased_region->init_req(2, epoch_ctrl);
  1724     old_phi->init_req(2, mark_node);
  1725     new_phi->init_req(2, o_node);
  1727     // rebiased_region->in(1) is set to fast path.
  1728     // The epoch of the current bias is still valid but we know
  1729     // nothing about the owner; it might be set or it might be clear.
  1730     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
  1731                              markOopDesc::age_mask_in_place |
  1732                              markOopDesc::epoch_mask_in_place);
  1733     Node* old = transform_later(new (C, 3) AndXNode(mark_node, cmask));
  1734     cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
  1735     Node* new_mark = transform_later(new (C, 3) OrXNode(cast_thread, old));
  1736     old_phi->init_req(1, old);
  1737     new_phi->init_req(1, new_mark);
  1739     transform_later(rebiased_region);
  1740     transform_later(old_phi);
  1741     transform_later(new_phi);
  1743     // Try to acquire the bias of the object using an atomic operation.
  1744     // If this fails we will go in to the runtime to revoke the object's bias.
  1745     cas = new (C, 5) StoreXConditionalNode(rebiased_region, mem, adr,
  1746                                            new_phi, old_phi);
  1747     transform_later(cas);
  1748     proj = transform_later( new (C, 1) SCMemProjNode(cas));
  1750     // Get slow path - Failed to CAS.
  1751     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
  1752     mem_phi->init_req(4, proj);
  1753     // region->in(4) is set to fast path - the object is rebiased to the current thread.
  1755     // Failed to CAS.
  1756     slow_path  = new (C, 3) RegionNode(3);
  1757     Node *slow_mem = new (C, 3) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
  1759     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
  1760     slow_mem->init_req(1, proj);
  1762     // Call CAS-based locking scheme (FastLock node).
  1764     transform_later(fast_lock_region);
  1765     transform_later(fast_lock_mem_phi);
  1767     // Get slow path - FastLock failed to lock the object.
  1768     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
  1769     mem_phi->init_req(2, fast_lock_mem_phi);
  1770     // region->in(2) is set to fast path - the object is locked to the current thread.
  1772     slow_path->init_req(2, ctrl); // Capture slow-control
  1773     slow_mem->init_req(2, fast_lock_mem_phi);
  1775     transform_later(slow_path);
  1776     transform_later(slow_mem);
  1777     // Reset lock's memory edge.
  1778     lock->set_req(TypeFunc::Memory, slow_mem);
  1780   } else {
  1781     region  = new (C, 3) RegionNode(3);
  1782     // create a Phi for the memory state
  1783     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1785     // Optimize test; set region slot 2
  1786     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
  1787     mem_phi->init_req(2, mem);
  1790   // Make slow path call
  1791   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
  1793   extract_call_projections(call);
  1795   // Slow path can only throw asynchronous exceptions, which are always
  1796   // de-opted.  So the compiler thinks the slow-call can never throw an
  1797   // exception.  If it DOES throw an exception we would need the debug
  1798   // info removed first (since if it throws there is no monitor).
  1799   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  1800            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  1802   // Capture slow path
  1803   // disconnect fall-through projection from call and create a new one
  1804   // hook up users of fall-through projection to region
  1805   Node *slow_ctrl = _fallthroughproj->clone();
  1806   transform_later(slow_ctrl);
  1807   _igvn.hash_delete(_fallthroughproj);
  1808   _fallthroughproj->disconnect_inputs(NULL);
  1809   region->init_req(1, slow_ctrl);
  1810   // region inputs are now complete
  1811   transform_later(region);
  1812   _igvn.subsume_node(_fallthroughproj, region);
  1814   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
  1815   mem_phi->init_req(1, memproj );
  1816   transform_later(mem_phi);
  1817   _igvn.hash_delete(_memproj_fallthrough);
  1818   _igvn.subsume_node(_memproj_fallthrough, mem_phi);
  1821 //------------------------------expand_unlock_node----------------------
  1822 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
  1824   Node* ctrl = unlock->in(TypeFunc::Control);
  1825   Node* mem = unlock->in(TypeFunc::Memory);
  1826   Node* obj = unlock->obj_node();
  1827   Node* box = unlock->box_node();
  1829   // No need for a null check on unlock
  1831   // Make the merge point
  1832   Node *region;
  1833   Node *mem_phi;
  1835   if (UseOptoBiasInlining) {
  1836     // Check for biased locking unlock case, which is a no-op.
  1837     // See the full descrition in MacroAssembler::biased_locking_exit().
  1838     region  = new (C, 4) RegionNode(4);
  1839     // create a Phi for the memory state
  1840     mem_phi = new (C, 4) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1841     mem_phi->init_req(3, mem);
  1843     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  1844     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
  1845                          markOopDesc::biased_lock_mask_in_place,
  1846                          markOopDesc::biased_lock_pattern);
  1847   } else {
  1848     region  = new (C, 3) RegionNode(3);
  1849     // create a Phi for the memory state
  1850     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1853   FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box );
  1854   funlock = transform_later( funlock )->as_FastUnlock();
  1855   // Optimize test; set region slot 2
  1856   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
  1858   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 );
  1860   extract_call_projections(call);
  1862   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  1863            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  1865   // No exceptions for unlocking
  1866   // Capture slow path
  1867   // disconnect fall-through projection from call and create a new one
  1868   // hook up users of fall-through projection to region
  1869   Node *slow_ctrl = _fallthroughproj->clone();
  1870   transform_later(slow_ctrl);
  1871   _igvn.hash_delete(_fallthroughproj);
  1872   _fallthroughproj->disconnect_inputs(NULL);
  1873   region->init_req(1, slow_ctrl);
  1874   // region inputs are now complete
  1875   transform_later(region);
  1876   _igvn.subsume_node(_fallthroughproj, region);
  1878   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
  1879   mem_phi->init_req(1, memproj );
  1880   mem_phi->init_req(2, mem);
  1881   transform_later(mem_phi);
  1882   _igvn.hash_delete(_memproj_fallthrough);
  1883   _igvn.subsume_node(_memproj_fallthrough, mem_phi);
  1886 //------------------------------expand_macro_nodes----------------------
  1887 //  Returns true if a failure occurred.
  1888 bool PhaseMacroExpand::expand_macro_nodes() {
  1889   if (C->macro_count() == 0)
  1890     return false;
  1891   // attempt to eliminate allocations
  1892   bool progress = true;
  1893   while (progress) {
  1894     progress = false;
  1895     for (int i = C->macro_count(); i > 0; i--) {
  1896       Node * n = C->macro_node(i-1);
  1897       bool success = false;
  1898       debug_only(int old_macro_count = C->macro_count(););
  1899       switch (n->class_id()) {
  1900       case Node::Class_Allocate:
  1901       case Node::Class_AllocateArray:
  1902         success = eliminate_allocate_node(n->as_Allocate());
  1903         break;
  1904       case Node::Class_Lock:
  1905       case Node::Class_Unlock:
  1906         success = eliminate_locking_node(n->as_AbstractLock());
  1907         break;
  1908       default:
  1909         if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
  1910           _igvn.add_users_to_worklist(n);
  1911           _igvn.hash_delete(n);
  1912           _igvn.subsume_node(n, n->in(1));
  1913           success = true;
  1914         } else {
  1915           assert(false, "unknown node type in macro list");
  1918       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  1919       progress = progress || success;
  1922   // Make sure expansion will not cause node limit to be exceeded.
  1923   // Worst case is a macro node gets expanded into about 50 nodes.
  1924   // Allow 50% more for optimization.
  1925   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
  1926     return true;
  1928   // expand "macro" nodes
  1929   // nodes are removed from the macro list as they are processed
  1930   while (C->macro_count() > 0) {
  1931     int macro_count = C->macro_count();
  1932     Node * n = C->macro_node(macro_count-1);
  1933     assert(n->is_macro(), "only macro nodes expected here");
  1934     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
  1935       // node is unreachable, so don't try to expand it
  1936       C->remove_macro_node(n);
  1937       continue;
  1939     switch (n->class_id()) {
  1940     case Node::Class_Allocate:
  1941       expand_allocate(n->as_Allocate());
  1942       break;
  1943     case Node::Class_AllocateArray:
  1944       expand_allocate_array(n->as_AllocateArray());
  1945       break;
  1946     case Node::Class_Lock:
  1947       expand_lock_node(n->as_Lock());
  1948       break;
  1949     case Node::Class_Unlock:
  1950       expand_unlock_node(n->as_Unlock());
  1951       break;
  1952     default:
  1953       assert(false, "unknown node type in macro list");
  1955     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
  1956     if (C->failing())  return true;
  1959   _igvn.set_delay_transform(false);
  1960   _igvn.optimize();
  1961   return false;

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