src/share/vm/opto/macro.cpp

Fri, 27 Feb 2009 13:27:09 -0800

author
twisti
date
Fri, 27 Feb 2009 13:27:09 -0800
changeset 1040
98cb887364d3
parent 1036
523ded093c31
child 1063
7bb995fbd3c0
permissions
-rw-r--r--

6810672: Comment typos
Summary: I have collected some typos I have found while looking at the code.
Reviewed-by: kvn, 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 != NULL && 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->set_req(0, newcall->in(0)); // reset control edge
    68         new_in = transform_later(new_in); // Register new node.
    69       }
    70       old_in = new_in;
    71     }
    72     newcall->add_req(old_in);
    73   }
    75   newcall->set_jvms(oldcall->jvms());
    76   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
    77     jvms->set_map(newcall);
    78     jvms->set_locoff(jvms->locoff()+jvms_adj);
    79     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
    80     jvms->set_monoff(jvms->monoff()+jvms_adj);
    81     jvms->set_scloff(jvms->scloff()+jvms_adj);
    82     jvms->set_endoff(jvms->endoff()+jvms_adj);
    83   }
    84 }
    86 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
    87   Node* cmp;
    88   if (mask != 0) {
    89     Node* and_node = transform_later(new (C, 3) AndXNode(word, MakeConX(mask)));
    90     cmp = transform_later(new (C, 3) CmpXNode(and_node, MakeConX(bits)));
    91   } else {
    92     cmp = word;
    93   }
    94   Node* bol = transform_later(new (C, 2) BoolNode(cmp, BoolTest::ne));
    95   IfNode* iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
    96   transform_later(iff);
    98   // Fast path taken.
    99   Node *fast_taken = transform_later( new (C, 1) IfFalseNode(iff) );
   101   // Fast path not-taken, i.e. slow path
   102   Node *slow_taken = transform_later( new (C, 1) IfTrueNode(iff) );
   104   if (return_fast_path) {
   105     region->init_req(edge, slow_taken); // Capture slow-control
   106     return fast_taken;
   107   } else {
   108     region->init_req(edge, fast_taken); // Capture fast-control
   109     return slow_taken;
   110   }
   111 }
   113 //--------------------copy_predefined_input_for_runtime_call--------------------
   114 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
   115   // Set fixed predefined input arguments
   116   call->init_req( TypeFunc::Control, ctrl );
   117   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
   118   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
   119   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
   120   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
   121 }
   123 //------------------------------make_slow_call---------------------------------
   124 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) {
   126   // Slow-path call
   127   int size = slow_call_type->domain()->cnt();
   128  CallNode *call = leaf_name
   129    ? (CallNode*)new (C, size) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
   130    : (CallNode*)new (C, size) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
   132   // Slow path call has no side-effects, uses few values
   133   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
   134   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
   135   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
   136   copy_call_debug_info(oldcall, call);
   137   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
   138   _igvn.hash_delete(oldcall);
   139   _igvn.subsume_node(oldcall, call);
   140   transform_later(call);
   142   return call;
   143 }
   145 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
   146   _fallthroughproj = NULL;
   147   _fallthroughcatchproj = NULL;
   148   _ioproj_fallthrough = NULL;
   149   _ioproj_catchall = NULL;
   150   _catchallcatchproj = NULL;
   151   _memproj_fallthrough = NULL;
   152   _memproj_catchall = NULL;
   153   _resproj = NULL;
   154   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
   155     ProjNode *pn = call->fast_out(i)->as_Proj();
   156     switch (pn->_con) {
   157       case TypeFunc::Control:
   158       {
   159         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
   160         _fallthroughproj = pn;
   161         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
   162         const Node *cn = pn->fast_out(j);
   163         if (cn->is_Catch()) {
   164           ProjNode *cpn = NULL;
   165           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
   166             cpn = cn->fast_out(k)->as_Proj();
   167             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
   168             if (cpn->_con == CatchProjNode::fall_through_index)
   169               _fallthroughcatchproj = cpn;
   170             else {
   171               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
   172               _catchallcatchproj = cpn;
   173             }
   174           }
   175         }
   176         break;
   177       }
   178       case TypeFunc::I_O:
   179         if (pn->_is_io_use)
   180           _ioproj_catchall = pn;
   181         else
   182           _ioproj_fallthrough = pn;
   183         break;
   184       case TypeFunc::Memory:
   185         if (pn->_is_io_use)
   186           _memproj_catchall = pn;
   187         else
   188           _memproj_fallthrough = pn;
   189         break;
   190       case TypeFunc::Parms:
   191         _resproj = pn;
   192         break;
   193       default:
   194         assert(false, "unexpected projection from allocation node.");
   195     }
   196   }
   198 }
   200 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
   201 void PhaseMacroExpand::eliminate_card_mark(Node *p2x) {
   202   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
   203   Node *shift = p2x->unique_out();
   204   Node *addp = shift->unique_out();
   205   for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
   206     Node *st = addp->last_out(j);
   207     assert(st->is_Store(), "store required");
   208     _igvn.replace_node(st, st->in(MemNode::Memory));
   209   }
   210 }
   212 // Search for a memory operation for the specified memory slice.
   213 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
   214   Node *orig_mem = mem;
   215   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   216   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
   217   while (true) {
   218     if (mem == alloc_mem || mem == start_mem ) {
   219       return mem;  // hit one of our sentinels
   220     } else if (mem->is_MergeMem()) {
   221       mem = mem->as_MergeMem()->memory_at(alias_idx);
   222     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
   223       Node *in = mem->in(0);
   224       // we can safely skip over safepoints, calls, locks and membars because we
   225       // already know that the object is safe to eliminate.
   226       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
   227         return in;
   228       } else if (in->is_Call()) {
   229         CallNode *call = in->as_Call();
   230         if (!call->may_modify(tinst, phase)) {
   231           mem = call->in(TypeFunc::Memory);
   232         }
   233         mem = in->in(TypeFunc::Memory);
   234       } else if (in->is_MemBar()) {
   235         mem = in->in(TypeFunc::Memory);
   236       } else {
   237         assert(false, "unexpected projection");
   238       }
   239     } else if (mem->is_Store()) {
   240       const TypePtr* atype = mem->as_Store()->adr_type();
   241       int adr_idx = Compile::current()->get_alias_index(atype);
   242       if (adr_idx == alias_idx) {
   243         assert(atype->isa_oopptr(), "address type must be oopptr");
   244         int adr_offset = atype->offset();
   245         uint adr_iid = atype->is_oopptr()->instance_id();
   246         // Array elements references have the same alias_idx
   247         // but different offset and different instance_id.
   248         if (adr_offset == offset && adr_iid == alloc->_idx)
   249           return mem;
   250       } else {
   251         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
   252       }
   253       mem = mem->in(MemNode::Memory);
   254     } else if (mem->Opcode() == Op_SCMemProj) {
   255       assert(mem->in(0)->is_LoadStore(), "sanity");
   256       const TypePtr* atype = mem->in(0)->in(MemNode::Address)->bottom_type()->is_ptr();
   257       int adr_idx = Compile::current()->get_alias_index(atype);
   258       if (adr_idx == alias_idx) {
   259         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
   260         return NULL;
   261       }
   262       mem = mem->in(0)->in(MemNode::Memory);
   263     } else {
   264       return mem;
   265     }
   266     assert(mem != orig_mem, "dead memory loop");
   267   }
   268 }
   270 //
   271 // Given a Memory Phi, compute a value Phi containing the values from stores
   272 // on the input paths.
   273 // Note: this function is recursive, its depth is limied by the "level" argument
   274 // Returns the computed Phi, or NULL if it cannot compute it.
   275 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) {
   276   assert(mem->is_Phi(), "sanity");
   277   int alias_idx = C->get_alias_index(adr_t);
   278   int offset = adr_t->offset();
   279   int instance_id = adr_t->instance_id();
   281   // Check if an appropriate value phi already exists.
   282   Node* region = mem->in(0);
   283   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
   284     Node* phi = region->fast_out(k);
   285     if (phi->is_Phi() && phi != mem &&
   286         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
   287       return phi;
   288     }
   289   }
   290   // Check if an appropriate new value phi already exists.
   291   Node* new_phi = NULL;
   292   uint size = value_phis->size();
   293   for (uint i=0; i < size; i++) {
   294     if ( mem->_idx == value_phis->index_at(i) ) {
   295       return value_phis->node_at(i);
   296     }
   297   }
   299   if (level <= 0) {
   300     return NULL; // Give up: phi tree too deep
   301   }
   302   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   303   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   305   uint length = mem->req();
   306   GrowableArray <Node *> values(length, length, NULL);
   308   // create a new Phi for the value
   309   PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
   310   transform_later(phi);
   311   value_phis->push(phi, mem->_idx);
   313   for (uint j = 1; j < length; j++) {
   314     Node *in = mem->in(j);
   315     if (in == NULL || in->is_top()) {
   316       values.at_put(j, in);
   317     } else  {
   318       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
   319       if (val == start_mem || val == alloc_mem) {
   320         // hit a sentinel, return appropriate 0 value
   321         values.at_put(j, _igvn.zerocon(ft));
   322         continue;
   323       }
   324       if (val->is_Initialize()) {
   325         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   326       }
   327       if (val == NULL) {
   328         return NULL;  // can't find a value on this path
   329       }
   330       if (val == mem) {
   331         values.at_put(j, mem);
   332       } else if (val->is_Store()) {
   333         values.at_put(j, val->in(MemNode::ValueIn));
   334       } else if(val->is_Proj() && val->in(0) == alloc) {
   335         values.at_put(j, _igvn.zerocon(ft));
   336       } else if (val->is_Phi()) {
   337         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
   338         if (val == NULL) {
   339           return NULL;
   340         }
   341         values.at_put(j, val);
   342       } else if (val->Opcode() == Op_SCMemProj) {
   343         assert(val->in(0)->is_LoadStore(), "sanity");
   344         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
   345         return NULL;
   346       } else {
   347 #ifdef ASSERT
   348         val->dump();
   349         assert(false, "unknown node on this path");
   350 #endif
   351         return NULL;  // unknown node on this path
   352       }
   353     }
   354   }
   355   // Set Phi's inputs
   356   for (uint j = 1; j < length; j++) {
   357     if (values.at(j) == mem) {
   358       phi->init_req(j, phi);
   359     } else {
   360       phi->init_req(j, values.at(j));
   361     }
   362   }
   363   return phi;
   364 }
   366 // Search the last value stored into the object's field.
   367 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
   368   assert(adr_t->is_known_instance_field(), "instance required");
   369   int instance_id = adr_t->instance_id();
   370   assert((uint)instance_id == alloc->_idx, "wrong allocation");
   372   int alias_idx = C->get_alias_index(adr_t);
   373   int offset = adr_t->offset();
   374   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   375   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
   376   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   377   Arena *a = Thread::current()->resource_area();
   378   VectorSet visited(a);
   381   bool done = sfpt_mem == alloc_mem;
   382   Node *mem = sfpt_mem;
   383   while (!done) {
   384     if (visited.test_set(mem->_idx)) {
   385       return NULL;  // found a loop, give up
   386     }
   387     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
   388     if (mem == start_mem || mem == alloc_mem) {
   389       done = true;  // hit a sentinel, return appropriate 0 value
   390     } else if (mem->is_Initialize()) {
   391       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   392       if (mem == NULL) {
   393         done = true; // Something go wrong.
   394       } else if (mem->is_Store()) {
   395         const TypePtr* atype = mem->as_Store()->adr_type();
   396         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
   397         done = true;
   398       }
   399     } else if (mem->is_Store()) {
   400       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
   401       assert(atype != NULL, "address type must be oopptr");
   402       assert(C->get_alias_index(atype) == alias_idx &&
   403              atype->is_known_instance_field() && atype->offset() == offset &&
   404              atype->instance_id() == instance_id, "store is correct memory slice");
   405       done = true;
   406     } else if (mem->is_Phi()) {
   407       // try to find a phi's unique input
   408       Node *unique_input = NULL;
   409       Node *top = C->top();
   410       for (uint i = 1; i < mem->req(); i++) {
   411         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
   412         if (n == NULL || n == top || n == mem) {
   413           continue;
   414         } else if (unique_input == NULL) {
   415           unique_input = n;
   416         } else if (unique_input != n) {
   417           unique_input = top;
   418           break;
   419         }
   420       }
   421       if (unique_input != NULL && unique_input != top) {
   422         mem = unique_input;
   423       } else {
   424         done = true;
   425       }
   426     } else {
   427       assert(false, "unexpected node");
   428     }
   429   }
   430   if (mem != NULL) {
   431     if (mem == start_mem || mem == alloc_mem) {
   432       // hit a sentinel, return appropriate 0 value
   433       return _igvn.zerocon(ft);
   434     } else if (mem->is_Store()) {
   435       return mem->in(MemNode::ValueIn);
   436     } else if (mem->is_Phi()) {
   437       // attempt to produce a Phi reflecting the values on the input paths of the Phi
   438       Node_Stack value_phis(a, 8);
   439       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
   440       if (phi != NULL) {
   441         return phi;
   442       } else {
   443         // Kill all new Phis
   444         while(value_phis.is_nonempty()) {
   445           Node* n = value_phis.node();
   446           _igvn.hash_delete(n);
   447           _igvn.subsume_node(n, C->top());
   448           value_phis.pop();
   449         }
   450       }
   451     }
   452   }
   453   // Something go wrong.
   454   return NULL;
   455 }
   457 // Check the possibility of scalar replacement.
   458 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   459   //  Scan the uses of the allocation to check for anything that would
   460   //  prevent us from eliminating it.
   461   NOT_PRODUCT( const char* fail_eliminate = NULL; )
   462   DEBUG_ONLY( Node* disq_node = NULL; )
   463   bool  can_eliminate = true;
   465   Node* res = alloc->result_cast();
   466   const TypeOopPtr* res_type = NULL;
   467   if (res == NULL) {
   468     // All users were eliminated.
   469   } else if (!res->is_CheckCastPP()) {
   470     alloc->_is_scalar_replaceable = false;  // don't try again
   471     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
   472     can_eliminate = false;
   473   } else {
   474     res_type = _igvn.type(res)->isa_oopptr();
   475     if (res_type == NULL) {
   476       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
   477       can_eliminate = false;
   478     } else if (res_type->isa_aryptr()) {
   479       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   480       if (length < 0) {
   481         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
   482         can_eliminate = false;
   483       }
   484     }
   485   }
   487   if (can_eliminate && res != NULL) {
   488     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
   489                                j < jmax && can_eliminate; j++) {
   490       Node* use = res->fast_out(j);
   492       if (use->is_AddP()) {
   493         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
   494         int offset = addp_type->offset();
   496         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
   497           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
   498           can_eliminate = false;
   499           break;
   500         }
   501         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
   502                                    k < kmax && can_eliminate; k++) {
   503           Node* n = use->fast_out(k);
   504           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
   505             DEBUG_ONLY(disq_node = n;)
   506             if (n->is_Load() || n->is_LoadStore()) {
   507               NOT_PRODUCT(fail_eliminate = "Field load";)
   508             } else {
   509               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
   510             }
   511             can_eliminate = false;
   512           }
   513         }
   514       } else if (use->is_SafePoint()) {
   515         SafePointNode* sfpt = use->as_SafePoint();
   516         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
   517           // Object is passed as argument.
   518           DEBUG_ONLY(disq_node = use;)
   519           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
   520           can_eliminate = false;
   521         }
   522         Node* sfptMem = sfpt->memory();
   523         if (sfptMem == NULL || sfptMem->is_top()) {
   524           DEBUG_ONLY(disq_node = use;)
   525           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
   526           can_eliminate = false;
   527         } else {
   528           safepoints.append_if_missing(sfpt);
   529         }
   530       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
   531         if (use->is_Phi()) {
   532           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
   533             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   534           } else {
   535             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
   536           }
   537           DEBUG_ONLY(disq_node = use;)
   538         } else {
   539           if (use->Opcode() == Op_Return) {
   540             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   541           }else {
   542             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
   543           }
   544           DEBUG_ONLY(disq_node = use;)
   545         }
   546         can_eliminate = false;
   547       }
   548     }
   549   }
   551 #ifndef PRODUCT
   552   if (PrintEliminateAllocations) {
   553     if (can_eliminate) {
   554       tty->print("Scalar ");
   555       if (res == NULL)
   556         alloc->dump();
   557       else
   558         res->dump();
   559     } else {
   560       tty->print("NotScalar (%s)", fail_eliminate);
   561       if (res == NULL)
   562         alloc->dump();
   563       else
   564         res->dump();
   565 #ifdef ASSERT
   566       if (disq_node != NULL) {
   567           tty->print("  >>>> ");
   568           disq_node->dump();
   569       }
   570 #endif /*ASSERT*/
   571     }
   572   }
   573 #endif
   574   return can_eliminate;
   575 }
   577 // Do scalar replacement.
   578 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   579   GrowableArray <SafePointNode *> safepoints_done;
   581   ciKlass* klass = NULL;
   582   ciInstanceKlass* iklass = NULL;
   583   int nfields = 0;
   584   int array_base;
   585   int element_size;
   586   BasicType basic_elem_type;
   587   ciType* elem_type;
   589   Node* res = alloc->result_cast();
   590   const TypeOopPtr* res_type = NULL;
   591   if (res != NULL) { // Could be NULL when there are no users
   592     res_type = _igvn.type(res)->isa_oopptr();
   593   }
   595   if (res != NULL) {
   596     klass = res_type->klass();
   597     if (res_type->isa_instptr()) {
   598       // find the fields of the class which will be needed for safepoint debug information
   599       assert(klass->is_instance_klass(), "must be an instance klass.");
   600       iklass = klass->as_instance_klass();
   601       nfields = iklass->nof_nonstatic_fields();
   602     } else {
   603       // find the array's elements which will be needed for safepoint debug information
   604       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   605       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
   606       elem_type = klass->as_array_klass()->element_type();
   607       basic_elem_type = elem_type->basic_type();
   608       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
   609       element_size = type2aelembytes(basic_elem_type);
   610     }
   611   }
   612   //
   613   // Process the safepoint uses
   614   //
   615   while (safepoints.length() > 0) {
   616     SafePointNode* sfpt = safepoints.pop();
   617     Node* mem = sfpt->memory();
   618     uint first_ind = sfpt->req();
   619     SafePointScalarObjectNode* sobj = new (C, 1) SafePointScalarObjectNode(res_type,
   620 #ifdef ASSERT
   621                                                  alloc,
   622 #endif
   623                                                  first_ind, nfields);
   624     sobj->init_req(0, sfpt->in(TypeFunc::Control));
   625     transform_later(sobj);
   627     // Scan object's fields adding an input to the safepoint for each field.
   628     for (int j = 0; j < nfields; j++) {
   629       intptr_t offset;
   630       ciField* field = NULL;
   631       if (iklass != NULL) {
   632         field = iklass->nonstatic_field_at(j);
   633         offset = field->offset();
   634         elem_type = field->type();
   635         basic_elem_type = field->layout_type();
   636       } else {
   637         offset = array_base + j * (intptr_t)element_size;
   638       }
   640       const Type *field_type;
   641       // The next code is taken from Parse::do_get_xxx().
   642       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
   643         if (!elem_type->is_loaded()) {
   644           field_type = TypeInstPtr::BOTTOM;
   645         } else if (field != NULL && field->is_constant()) {
   646           // This can happen if the constant oop is non-perm.
   647           ciObject* con = field->constant_value().as_object();
   648           // Do not "join" in the previous type; it doesn't add value,
   649           // and may yield a vacuous result if the field is of interface type.
   650           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
   651           assert(field_type != NULL, "field singleton type must be consistent");
   652         } else {
   653           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
   654         }
   655         if (UseCompressedOops) {
   656           field_type = field_type->make_narrowoop();
   657           basic_elem_type = T_NARROWOOP;
   658         }
   659       } else {
   660         field_type = Type::get_const_basic_type(basic_elem_type);
   661       }
   663       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
   665       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
   666       if (field_val == NULL) {
   667         // we weren't able to find a value for this field,
   668         // give up on eliminating this allocation
   669         alloc->_is_scalar_replaceable = false;  // don't try again
   670         // remove any extra entries we added to the safepoint
   671         uint last = sfpt->req() - 1;
   672         for (int k = 0;  k < j; k++) {
   673           sfpt->del_req(last--);
   674         }
   675         // rollback processed safepoints
   676         while (safepoints_done.length() > 0) {
   677           SafePointNode* sfpt_done = safepoints_done.pop();
   678           // remove any extra entries we added to the safepoint
   679           last = sfpt_done->req() - 1;
   680           for (int k = 0;  k < nfields; k++) {
   681             sfpt_done->del_req(last--);
   682           }
   683           JVMState *jvms = sfpt_done->jvms();
   684           jvms->set_endoff(sfpt_done->req());
   685           // Now make a pass over the debug information replacing any references
   686           // to SafePointScalarObjectNode with the allocated object.
   687           int start = jvms->debug_start();
   688           int end   = jvms->debug_end();
   689           for (int i = start; i < end; i++) {
   690             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
   691               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
   692               if (scobj->first_index() == sfpt_done->req() &&
   693                   scobj->n_fields() == (uint)nfields) {
   694                 assert(scobj->alloc() == alloc, "sanity");
   695                 sfpt_done->set_req(i, res);
   696               }
   697             }
   698           }
   699         }
   700 #ifndef PRODUCT
   701         if (PrintEliminateAllocations) {
   702           if (field != NULL) {
   703             tty->print("=== At SafePoint node %d can't find value of Field: ",
   704                        sfpt->_idx);
   705             field->print();
   706             int field_idx = C->get_alias_index(field_addr_type);
   707             tty->print(" (alias_idx=%d)", field_idx);
   708           } else { // Array's element
   709             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
   710                        sfpt->_idx, j);
   711           }
   712           tty->print(", which prevents elimination of: ");
   713           if (res == NULL)
   714             alloc->dump();
   715           else
   716             res->dump();
   717         }
   718 #endif
   719         return false;
   720       }
   721       if (UseCompressedOops && field_type->isa_narrowoop()) {
   722         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
   723         // to be able scalar replace the allocation.
   724         if (field_val->is_EncodeP()) {
   725           field_val = field_val->in(1);
   726         } else {
   727           field_val = transform_later(new (C, 2) DecodeNNode(field_val, field_val->bottom_type()->make_ptr()));
   728         }
   729       }
   730       sfpt->add_req(field_val);
   731     }
   732     JVMState *jvms = sfpt->jvms();
   733     jvms->set_endoff(sfpt->req());
   734     // Now make a pass over the debug information replacing any references
   735     // to the allocated object with "sobj"
   736     int start = jvms->debug_start();
   737     int end   = jvms->debug_end();
   738     for (int i = start; i < end; i++) {
   739       if (sfpt->in(i) == res) {
   740         sfpt->set_req(i, sobj);
   741       }
   742     }
   743     safepoints_done.append_if_missing(sfpt); // keep it for rollback
   744   }
   745   return true;
   746 }
   748 // Process users of eliminated allocation.
   749 void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
   750   Node* res = alloc->result_cast();
   751   if (res != NULL) {
   752     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
   753       Node *use = res->last_out(j);
   754       uint oc1 = res->outcnt();
   756       if (use->is_AddP()) {
   757         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
   758           Node *n = use->last_out(k);
   759           uint oc2 = use->outcnt();
   760           if (n->is_Store()) {
   761             _igvn.replace_node(n, n->in(MemNode::Memory));
   762           } else {
   763             assert( n->Opcode() == Op_CastP2X, "CastP2X required");
   764             eliminate_card_mark(n);
   765           }
   766           k -= (oc2 - use->outcnt());
   767         }
   768       } else {
   769         assert( !use->is_SafePoint(), "safepoint uses must have been already elimiated");
   770         assert( use->Opcode() == Op_CastP2X, "CastP2X required");
   771         eliminate_card_mark(use);
   772       }
   773       j -= (oc1 - res->outcnt());
   774     }
   775     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
   776     _igvn.remove_dead_node(res);
   777   }
   779   //
   780   // Process other users of allocation's projections
   781   //
   782   if (_resproj != NULL && _resproj->outcnt() != 0) {
   783     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
   784       Node *use = _resproj->last_out(j);
   785       uint oc1 = _resproj->outcnt();
   786       if (use->is_Initialize()) {
   787         // Eliminate Initialize node.
   788         InitializeNode *init = use->as_Initialize();
   789         assert(init->outcnt() <= 2, "only a control and memory projection expected");
   790         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
   791         if (ctrl_proj != NULL) {
   792            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
   793           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
   794         }
   795         Node *mem_proj = init->proj_out(TypeFunc::Memory);
   796         if (mem_proj != NULL) {
   797           Node *mem = init->in(TypeFunc::Memory);
   798 #ifdef ASSERT
   799           if (mem->is_MergeMem()) {
   800             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
   801           } else {
   802             assert(mem == _memproj_fallthrough, "allocation memory projection");
   803           }
   804 #endif
   805           _igvn.replace_node(mem_proj, mem);
   806         }
   807       } else if (use->is_AddP()) {
   808         // raw memory addresses used only by the initialization
   809         _igvn.hash_delete(use);
   810         _igvn.subsume_node(use, C->top());
   811       } else  {
   812         assert(false, "only Initialize or AddP expected");
   813       }
   814       j -= (oc1 - _resproj->outcnt());
   815     }
   816   }
   817   if (_fallthroughcatchproj != NULL) {
   818     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
   819   }
   820   if (_memproj_fallthrough != NULL) {
   821     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
   822   }
   823   if (_memproj_catchall != NULL) {
   824     _igvn.replace_node(_memproj_catchall, C->top());
   825   }
   826   if (_ioproj_fallthrough != NULL) {
   827     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
   828   }
   829   if (_ioproj_catchall != NULL) {
   830     _igvn.replace_node(_ioproj_catchall, C->top());
   831   }
   832   if (_catchallcatchproj != NULL) {
   833     _igvn.replace_node(_catchallcatchproj, C->top());
   834   }
   835 }
   837 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
   839   if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {
   840     return false;
   841   }
   843   extract_call_projections(alloc);
   845   GrowableArray <SafePointNode *> safepoints;
   846   if (!can_eliminate_allocation(alloc, safepoints)) {
   847     return false;
   848   }
   850   if (!scalar_replacement(alloc, safepoints)) {
   851     return false;
   852   }
   854   process_users_of_allocation(alloc);
   856 #ifndef PRODUCT
   857 if (PrintEliminateAllocations) {
   858   if (alloc->is_AllocateArray())
   859     tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
   860   else
   861     tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
   862 }
   863 #endif
   865   return true;
   866 }
   869 //---------------------------set_eden_pointers-------------------------
   870 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
   871   if (UseTLAB) {                // Private allocation: load from TLS
   872     Node* thread = transform_later(new (C, 1) ThreadLocalNode());
   873     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
   874     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
   875     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
   876     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
   877   } else {                      // Shared allocation: load from globals
   878     CollectedHeap* ch = Universe::heap();
   879     address top_adr = (address)ch->top_addr();
   880     address end_adr = (address)ch->end_addr();
   881     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
   882     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
   883   }
   884 }
   887 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
   888   Node* adr = basic_plus_adr(base, offset);
   889   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
   890   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
   891   transform_later(value);
   892   return value;
   893 }
   896 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
   897   Node* adr = basic_plus_adr(base, offset);
   898   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
   899   transform_later(mem);
   900   return mem;
   901 }
   903 //=============================================================================
   904 //
   905 //                              A L L O C A T I O N
   906 //
   907 // Allocation attempts to be fast in the case of frequent small objects.
   908 // It breaks down like this:
   909 //
   910 // 1) Size in doublewords is computed.  This is a constant for objects and
   911 // variable for most arrays.  Doubleword units are used to avoid size
   912 // overflow of huge doubleword arrays.  We need doublewords in the end for
   913 // rounding.
   914 //
   915 // 2) Size is checked for being 'too large'.  Too-large allocations will go
   916 // the slow path into the VM.  The slow path can throw any required
   917 // exceptions, and does all the special checks for very large arrays.  The
   918 // size test can constant-fold away for objects.  For objects with
   919 // finalizers it constant-folds the otherway: you always go slow with
   920 // finalizers.
   921 //
   922 // 3) If NOT using TLABs, this is the contended loop-back point.
   923 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
   924 //
   925 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
   926 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
   927 // "size*8" we always enter the VM, where "largish" is a constant picked small
   928 // enough that there's always space between the eden max and 4Gig (old space is
   929 // there so it's quite large) and large enough that the cost of entering the VM
   930 // is dwarfed by the cost to initialize the space.
   931 //
   932 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
   933 // down.  If contended, repeat at step 3.  If using TLABs normal-store
   934 // adjusted heap top back down; there is no contention.
   935 //
   936 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
   937 // fields.
   938 //
   939 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
   940 // oop flavor.
   941 //
   942 //=============================================================================
   943 // FastAllocateSizeLimit value is in DOUBLEWORDS.
   944 // Allocations bigger than this always go the slow route.
   945 // This value must be small enough that allocation attempts that need to
   946 // trigger exceptions go the slow route.  Also, it must be small enough so
   947 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
   948 //=============================================================================j//
   949 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
   950 // The allocator will coalesce int->oop copies away.  See comment in
   951 // coalesce.cpp about how this works.  It depends critically on the exact
   952 // code shape produced here, so if you are changing this code shape
   953 // make sure the GC info for the heap-top is correct in and around the
   954 // slow-path call.
   955 //
   957 void PhaseMacroExpand::expand_allocate_common(
   958             AllocateNode* alloc, // allocation node to be expanded
   959             Node* length,  // array length for an array allocation
   960             const TypeFunc* slow_call_type, // Type of slow call
   961             address slow_call_address  // Address of slow call
   962     )
   963 {
   965   Node* ctrl = alloc->in(TypeFunc::Control);
   966   Node* mem  = alloc->in(TypeFunc::Memory);
   967   Node* i_o  = alloc->in(TypeFunc::I_O);
   968   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
   969   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
   970   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
   972   assert(ctrl != NULL, "must have control");
   973   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
   974   // they will not be used if "always_slow" is set
   975   enum { slow_result_path = 1, fast_result_path = 2 };
   976   Node *result_region;
   977   Node *result_phi_rawmem;
   978   Node *result_phi_rawoop;
   979   Node *result_phi_i_o;
   981   // The initial slow comparison is a size check, the comparison
   982   // we want to do is a BoolTest::gt
   983   bool always_slow = false;
   984   int tv = _igvn.find_int_con(initial_slow_test, -1);
   985   if (tv >= 0) {
   986     always_slow = (tv == 1);
   987     initial_slow_test = NULL;
   988   } else {
   989     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
   990   }
   992   if (DTraceAllocProbes ||
   993       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
   994                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
   995     // Force slow-path allocation
   996     always_slow = true;
   997     initial_slow_test = NULL;
   998   }
  1001   enum { too_big_or_final_path = 1, need_gc_path = 2 };
  1002   Node *slow_region = NULL;
  1003   Node *toobig_false = ctrl;
  1005   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
  1006   // generate the initial test if necessary
  1007   if (initial_slow_test != NULL ) {
  1008     slow_region = new (C, 3) RegionNode(3);
  1010     // Now make the initial failure test.  Usually a too-big test but
  1011     // might be a TRUE for finalizers or a fancy class check for
  1012     // newInstance0.
  1013     IfNode *toobig_iff = new (C, 2) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
  1014     transform_later(toobig_iff);
  1015     // Plug the failing-too-big test into the slow-path region
  1016     Node *toobig_true = new (C, 1) IfTrueNode( toobig_iff );
  1017     transform_later(toobig_true);
  1018     slow_region    ->init_req( too_big_or_final_path, toobig_true );
  1019     toobig_false = new (C, 1) IfFalseNode( toobig_iff );
  1020     transform_later(toobig_false);
  1021   } else {         // No initial test, just fall into next case
  1022     toobig_false = ctrl;
  1023     debug_only(slow_region = NodeSentinel);
  1026   Node *slow_mem = mem;  // save the current memory state for slow path
  1027   // generate the fast allocation code unless we know that the initial test will always go slow
  1028   if (!always_slow) {
  1029     // Fast path modifies only raw memory.
  1030     if (mem->is_MergeMem()) {
  1031       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
  1034     Node* eden_top_adr;
  1035     Node* eden_end_adr;
  1037     set_eden_pointers(eden_top_adr, eden_end_adr);
  1039     // Load Eden::end.  Loop invariant and hoisted.
  1040     //
  1041     // Note: We set the control input on "eden_end" and "old_eden_top" when using
  1042     //       a TLAB to work around a bug where these values were being moved across
  1043     //       a safepoint.  These are not oops, so they cannot be include in the oop
  1044     //       map, but the can be changed by a GC.   The proper way to fix this would
  1045     //       be to set the raw memory state when generating a  SafepointNode.  However
  1046     //       this will require extensive changes to the loop optimization in order to
  1047     //       prevent a degradation of the optimization.
  1048     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
  1049     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
  1051     // allocate the Region and Phi nodes for the result
  1052     result_region = new (C, 3) RegionNode(3);
  1053     result_phi_rawmem = new (C, 3) PhiNode( result_region, Type::MEMORY, TypeRawPtr::BOTTOM );
  1054     result_phi_rawoop = new (C, 3) PhiNode( result_region, TypeRawPtr::BOTTOM );
  1055     result_phi_i_o    = new (C, 3) PhiNode( result_region, Type::ABIO ); // I/O is used for Prefetch
  1057     // We need a Region for the loop-back contended case.
  1058     enum { fall_in_path = 1, contended_loopback_path = 2 };
  1059     Node *contended_region;
  1060     Node *contended_phi_rawmem;
  1061     if( UseTLAB ) {
  1062       contended_region = toobig_false;
  1063       contended_phi_rawmem = mem;
  1064     } else {
  1065       contended_region = new (C, 3) RegionNode(3);
  1066       contended_phi_rawmem = new (C, 3) PhiNode( contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1067       // Now handle the passing-too-big test.  We fall into the contended
  1068       // loop-back merge point.
  1069       contended_region    ->init_req( fall_in_path, toobig_false );
  1070       contended_phi_rawmem->init_req( fall_in_path, mem );
  1071       transform_later(contended_region);
  1072       transform_later(contended_phi_rawmem);
  1075     // Load(-locked) the heap top.
  1076     // See note above concerning the control input when using a TLAB
  1077     Node *old_eden_top = UseTLAB
  1078       ? new (C, 3) LoadPNode     ( ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM )
  1079       : new (C, 3) LoadPLockedNode( contended_region, contended_phi_rawmem, eden_top_adr );
  1081     transform_later(old_eden_top);
  1082     // Add to heap top to get a new heap top
  1083     Node *new_eden_top = new (C, 4) AddPNode( top(), old_eden_top, size_in_bytes );
  1084     transform_later(new_eden_top);
  1085     // Check for needing a GC; compare against heap end
  1086     Node *needgc_cmp = new (C, 3) CmpPNode( new_eden_top, eden_end );
  1087     transform_later(needgc_cmp);
  1088     Node *needgc_bol = new (C, 2) BoolNode( needgc_cmp, BoolTest::ge );
  1089     transform_later(needgc_bol);
  1090     IfNode *needgc_iff = new (C, 2) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
  1091     transform_later(needgc_iff);
  1093     // Plug the failing-heap-space-need-gc test into the slow-path region
  1094     Node *needgc_true = new (C, 1) IfTrueNode( needgc_iff );
  1095     transform_later(needgc_true);
  1096     if( initial_slow_test ) {
  1097       slow_region    ->init_req( need_gc_path, needgc_true );
  1098       // This completes all paths into the slow merge point
  1099       transform_later(slow_region);
  1100     } else {                      // No initial slow path needed!
  1101       // Just fall from the need-GC path straight into the VM call.
  1102       slow_region    = needgc_true;
  1104     // No need for a GC.  Setup for the Store-Conditional
  1105     Node *needgc_false = new (C, 1) IfFalseNode( needgc_iff );
  1106     transform_later(needgc_false);
  1108     // Grab regular I/O before optional prefetch may change it.
  1109     // Slow-path does no I/O so just set it to the original I/O.
  1110     result_phi_i_o->init_req( slow_result_path, i_o );
  1112     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
  1113                               old_eden_top, new_eden_top, length);
  1115     // Store (-conditional) the modified eden top back down.
  1116     // StorePConditional produces flags for a test PLUS a modified raw
  1117     // memory state.
  1118     Node *store_eden_top;
  1119     Node *fast_oop_ctrl;
  1120     if( UseTLAB ) {
  1121       store_eden_top = new (C, 4) StorePNode( needgc_false, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, new_eden_top );
  1122       transform_later(store_eden_top);
  1123       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
  1124     } else {
  1125       store_eden_top = new (C, 5) StorePConditionalNode( needgc_false, contended_phi_rawmem, eden_top_adr, new_eden_top, old_eden_top );
  1126       transform_later(store_eden_top);
  1127       Node *contention_check = new (C, 2) BoolNode( store_eden_top, BoolTest::ne );
  1128       transform_later(contention_check);
  1129       store_eden_top = new (C, 1) SCMemProjNode(store_eden_top);
  1130       transform_later(store_eden_top);
  1132       // If not using TLABs, check to see if there was contention.
  1133       IfNode *contention_iff = new (C, 2) IfNode ( needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN );
  1134       transform_later(contention_iff);
  1135       Node *contention_true = new (C, 1) IfTrueNode( contention_iff );
  1136       transform_later(contention_true);
  1137       // If contention, loopback and try again.
  1138       contended_region->init_req( contended_loopback_path, contention_true );
  1139       contended_phi_rawmem->init_req( contended_loopback_path, store_eden_top );
  1141       // Fast-path succeeded with no contention!
  1142       Node *contention_false = new (C, 1) IfFalseNode( contention_iff );
  1143       transform_later(contention_false);
  1144       fast_oop_ctrl = contention_false;
  1147     // Rename successful fast-path variables to make meaning more obvious
  1148     Node* fast_oop        = old_eden_top;
  1149     Node* fast_oop_rawmem = store_eden_top;
  1150     fast_oop_rawmem = initialize_object(alloc,
  1151                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
  1152                                         klass_node, length, size_in_bytes);
  1154     if (ExtendedDTraceProbes) {
  1155       // Slow-path call
  1156       int size = TypeFunc::Parms + 2;
  1157       CallLeafNode *call = new (C, size) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
  1158                                                       CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
  1159                                                       "dtrace_object_alloc",
  1160                                                       TypeRawPtr::BOTTOM);
  1162       // Get base of thread-local storage area
  1163       Node* thread = new (C, 1) ThreadLocalNode();
  1164       transform_later(thread);
  1166       call->init_req(TypeFunc::Parms+0, thread);
  1167       call->init_req(TypeFunc::Parms+1, fast_oop);
  1168       call->init_req( TypeFunc::Control, fast_oop_ctrl );
  1169       call->init_req( TypeFunc::I_O    , top() )        ;   // does no i/o
  1170       call->init_req( TypeFunc::Memory , fast_oop_rawmem );
  1171       call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
  1172       call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
  1173       transform_later(call);
  1174       fast_oop_ctrl = new (C, 1) ProjNode(call,TypeFunc::Control);
  1175       transform_later(fast_oop_ctrl);
  1176       fast_oop_rawmem = new (C, 1) ProjNode(call,TypeFunc::Memory);
  1177       transform_later(fast_oop_rawmem);
  1180     // Plug in the successful fast-path into the result merge point
  1181     result_region    ->init_req( fast_result_path, fast_oop_ctrl );
  1182     result_phi_rawoop->init_req( fast_result_path, fast_oop );
  1183     result_phi_i_o   ->init_req( fast_result_path, i_o );
  1184     result_phi_rawmem->init_req( fast_result_path, fast_oop_rawmem );
  1185   } else {
  1186     slow_region = ctrl;
  1189   // Generate slow-path call
  1190   CallNode *call = new (C, slow_call_type->domain()->cnt())
  1191     CallStaticJavaNode(slow_call_type, slow_call_address,
  1192                        OptoRuntime::stub_name(slow_call_address),
  1193                        alloc->jvms()->bci(),
  1194                        TypePtr::BOTTOM);
  1195   call->init_req( TypeFunc::Control, slow_region );
  1196   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
  1197   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
  1198   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
  1199   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
  1201   call->init_req(TypeFunc::Parms+0, klass_node);
  1202   if (length != NULL) {
  1203     call->init_req(TypeFunc::Parms+1, length);
  1206   // Copy debug information and adjust JVMState information, then replace
  1207   // allocate node with the call
  1208   copy_call_debug_info((CallNode *) alloc,  call);
  1209   if (!always_slow) {
  1210     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
  1212   _igvn.hash_delete(alloc);
  1213   _igvn.subsume_node(alloc, call);
  1214   transform_later(call);
  1216   // Identify the output projections from the allocate node and
  1217   // adjust any references to them.
  1218   // The control and io projections look like:
  1219   //
  1220   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
  1221   //  Allocate                   Catch
  1222   //        ^---Proj(io) <-------+   ^---CatchProj(io)
  1223   //
  1224   //  We are interested in the CatchProj nodes.
  1225   //
  1226   extract_call_projections(call);
  1228   // An allocate node has separate memory projections for the uses on the control and i_o paths
  1229   // Replace uses of the control memory projection with result_phi_rawmem (unless we are only generating a slow call)
  1230   if (!always_slow && _memproj_fallthrough != NULL) {
  1231     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1232       Node *use = _memproj_fallthrough->fast_out(i);
  1233       _igvn.hash_delete(use);
  1234       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
  1235       _igvn._worklist.push(use);
  1236       // back up iterator
  1237       --i;
  1240   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete _memproj_catchall so
  1241   // we end up with a call that has only 1 memory projection
  1242   if (_memproj_catchall != NULL ) {
  1243     if (_memproj_fallthrough == NULL) {
  1244       _memproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::Memory);
  1245       transform_later(_memproj_fallthrough);
  1247     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
  1248       Node *use = _memproj_catchall->fast_out(i);
  1249       _igvn.hash_delete(use);
  1250       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
  1251       _igvn._worklist.push(use);
  1252       // back up iterator
  1253       --i;
  1257   // An allocate node has separate i_o projections for the uses on the control and i_o paths
  1258   // Replace uses of the control i_o projection with result_phi_i_o (unless we are only generating a slow call)
  1259   if (_ioproj_fallthrough == NULL) {
  1260     _ioproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::I_O);
  1261     transform_later(_ioproj_fallthrough);
  1262   } else if (!always_slow) {
  1263     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1264       Node *use = _ioproj_fallthrough->fast_out(i);
  1266       _igvn.hash_delete(use);
  1267       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
  1268       _igvn._worklist.push(use);
  1269       // back up iterator
  1270       --i;
  1273   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete _ioproj_catchall so
  1274   // we end up with a call that has only 1 control projection
  1275   if (_ioproj_catchall != NULL ) {
  1276     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
  1277       Node *use = _ioproj_catchall->fast_out(i);
  1278       _igvn.hash_delete(use);
  1279       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
  1280       _igvn._worklist.push(use);
  1281       // back up iterator
  1282       --i;
  1286   // if we generated only a slow call, we are done
  1287   if (always_slow)
  1288     return;
  1291   if (_fallthroughcatchproj != NULL) {
  1292     ctrl = _fallthroughcatchproj->clone();
  1293     transform_later(ctrl);
  1294     _igvn.hash_delete(_fallthroughcatchproj);
  1295     _igvn.subsume_node(_fallthroughcatchproj, result_region);
  1296   } else {
  1297     ctrl = top();
  1299   Node *slow_result;
  1300   if (_resproj == NULL) {
  1301     // no uses of the allocation result
  1302     slow_result = top();
  1303   } else {
  1304     slow_result = _resproj->clone();
  1305     transform_later(slow_result);
  1306     _igvn.hash_delete(_resproj);
  1307     _igvn.subsume_node(_resproj, result_phi_rawoop);
  1310   // Plug slow-path into result merge point
  1311   result_region    ->init_req( slow_result_path, ctrl );
  1312   result_phi_rawoop->init_req( slow_result_path, slow_result);
  1313   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
  1314   transform_later(result_region);
  1315   transform_later(result_phi_rawoop);
  1316   transform_later(result_phi_rawmem);
  1317   transform_later(result_phi_i_o);
  1318   // This completes all paths into the result merge point
  1322 // Helper for PhaseMacroExpand::expand_allocate_common.
  1323 // Initializes the newly-allocated storage.
  1324 Node*
  1325 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
  1326                                     Node* control, Node* rawmem, Node* object,
  1327                                     Node* klass_node, Node* length,
  1328                                     Node* size_in_bytes) {
  1329   InitializeNode* init = alloc->initialization();
  1330   // Store the klass & mark bits
  1331   Node* mark_node = NULL;
  1332   // For now only enable fast locking for non-array types
  1333   if (UseBiasedLocking && (length == NULL)) {
  1334     mark_node = make_load(NULL, rawmem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeRawPtr::BOTTOM, T_ADDRESS);
  1335   } else {
  1336     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
  1338   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
  1340   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_OBJECT);
  1341   int header_size = alloc->minimum_header_size();  // conservatively small
  1343   // Array length
  1344   if (length != NULL) {         // Arrays need length field
  1345     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
  1346     // conservatively small header size:
  1347     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1348     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1349     if (k->is_array_klass())    // we know the exact header size in most cases:
  1350       header_size = Klass::layout_helper_header_size(k->layout_helper());
  1353   // Clear the object body, if necessary.
  1354   if (init == NULL) {
  1355     // The init has somehow disappeared; be cautious and clear everything.
  1356     //
  1357     // This can happen if a node is allocated but an uncommon trap occurs
  1358     // immediately.  In this case, the Initialize gets associated with the
  1359     // trap, and may be placed in a different (outer) loop, if the Allocate
  1360     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
  1361     // there can be two Allocates to one Initialize.  The answer in all these
  1362     // edge cases is safety first.  It is always safe to clear immediately
  1363     // within an Allocate, and then (maybe or maybe not) clear some more later.
  1364     if (!ZeroTLAB)
  1365       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
  1366                                             header_size, size_in_bytes,
  1367                                             &_igvn);
  1368   } else {
  1369     if (!init->is_complete()) {
  1370       // Try to win by zeroing only what the init does not store.
  1371       // We can also try to do some peephole optimizations,
  1372       // such as combining some adjacent subword stores.
  1373       rawmem = init->complete_stores(control, rawmem, object,
  1374                                      header_size, size_in_bytes, &_igvn);
  1376     // We have no more use for this link, since the AllocateNode goes away:
  1377     init->set_req(InitializeNode::RawAddress, top());
  1378     // (If we keep the link, it just confuses the register allocator,
  1379     // who thinks he sees a real use of the address by the membar.)
  1382   return rawmem;
  1385 // Generate prefetch instructions for next allocations.
  1386 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
  1387                                         Node*& contended_phi_rawmem,
  1388                                         Node* old_eden_top, Node* new_eden_top,
  1389                                         Node* length) {
  1390    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
  1391       // Generate prefetch allocation with watermark check.
  1392       // As an allocation hits the watermark, we will prefetch starting
  1393       // at a "distance" away from watermark.
  1394       enum { fall_in_path = 1, pf_path = 2 };
  1396       Node *pf_region = new (C, 3) RegionNode(3);
  1397       Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
  1398                                                 TypeRawPtr::BOTTOM );
  1399       // I/O is used for Prefetch
  1400       Node *pf_phi_abio = new (C, 3) PhiNode( pf_region, Type::ABIO );
  1402       Node *thread = new (C, 1) ThreadLocalNode();
  1403       transform_later(thread);
  1405       Node *eden_pf_adr = new (C, 4) AddPNode( top()/*not oop*/, thread,
  1406                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
  1407       transform_later(eden_pf_adr);
  1409       Node *old_pf_wm = new (C, 3) LoadPNode( needgc_false,
  1410                                    contended_phi_rawmem, eden_pf_adr,
  1411                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
  1412       transform_later(old_pf_wm);
  1414       // check against new_eden_top
  1415       Node *need_pf_cmp = new (C, 3) CmpPNode( new_eden_top, old_pf_wm );
  1416       transform_later(need_pf_cmp);
  1417       Node *need_pf_bol = new (C, 2) BoolNode( need_pf_cmp, BoolTest::ge );
  1418       transform_later(need_pf_bol);
  1419       IfNode *need_pf_iff = new (C, 2) IfNode( needgc_false, need_pf_bol,
  1420                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
  1421       transform_later(need_pf_iff);
  1423       // true node, add prefetchdistance
  1424       Node *need_pf_true = new (C, 1) IfTrueNode( need_pf_iff );
  1425       transform_later(need_pf_true);
  1427       Node *need_pf_false = new (C, 1) IfFalseNode( need_pf_iff );
  1428       transform_later(need_pf_false);
  1430       Node *new_pf_wmt = new (C, 4) AddPNode( top(), old_pf_wm,
  1431                                     _igvn.MakeConX(AllocatePrefetchDistance) );
  1432       transform_later(new_pf_wmt );
  1433       new_pf_wmt->set_req(0, need_pf_true);
  1435       Node *store_new_wmt = new (C, 4) StorePNode( need_pf_true,
  1436                                        contended_phi_rawmem, eden_pf_adr,
  1437                                        TypeRawPtr::BOTTOM, new_pf_wmt );
  1438       transform_later(store_new_wmt);
  1440       // adding prefetches
  1441       pf_phi_abio->init_req( fall_in_path, i_o );
  1443       Node *prefetch_adr;
  1444       Node *prefetch;
  1445       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
  1446       uint step_size = AllocatePrefetchStepSize;
  1447       uint distance = 0;
  1449       for ( uint i = 0; i < lines; i++ ) {
  1450         prefetch_adr = new (C, 4) AddPNode( old_pf_wm, new_pf_wmt,
  1451                                             _igvn.MakeConX(distance) );
  1452         transform_later(prefetch_adr);
  1453         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
  1454         transform_later(prefetch);
  1455         distance += step_size;
  1456         i_o = prefetch;
  1458       pf_phi_abio->set_req( pf_path, i_o );
  1460       pf_region->init_req( fall_in_path, need_pf_false );
  1461       pf_region->init_req( pf_path, need_pf_true );
  1463       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
  1464       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
  1466       transform_later(pf_region);
  1467       transform_later(pf_phi_rawmem);
  1468       transform_later(pf_phi_abio);
  1470       needgc_false = pf_region;
  1471       contended_phi_rawmem = pf_phi_rawmem;
  1472       i_o = pf_phi_abio;
  1473    } else if( AllocatePrefetchStyle > 0 ) {
  1474       // Insert a prefetch for each allocation only on the fast-path
  1475       Node *prefetch_adr;
  1476       Node *prefetch;
  1477       // Generate several prefetch instructions only for arrays.
  1478       uint lines = (length != NULL) ? AllocatePrefetchLines : 1;
  1479       uint step_size = AllocatePrefetchStepSize;
  1480       uint distance = AllocatePrefetchDistance;
  1481       for ( uint i = 0; i < lines; i++ ) {
  1482         prefetch_adr = new (C, 4) AddPNode( old_eden_top, new_eden_top,
  1483                                             _igvn.MakeConX(distance) );
  1484         transform_later(prefetch_adr);
  1485         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
  1486         // Do not let it float too high, since if eden_top == eden_end,
  1487         // both might be null.
  1488         if( i == 0 ) { // Set control for first prefetch, next follows it
  1489           prefetch->init_req(0, needgc_false);
  1491         transform_later(prefetch);
  1492         distance += step_size;
  1493         i_o = prefetch;
  1496    return i_o;
  1500 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
  1501   expand_allocate_common(alloc, NULL,
  1502                          OptoRuntime::new_instance_Type(),
  1503                          OptoRuntime::new_instance_Java());
  1506 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
  1507   Node* length = alloc->in(AllocateNode::ALength);
  1508   expand_allocate_common(alloc, length,
  1509                          OptoRuntime::new_array_Type(),
  1510                          OptoRuntime::new_array_Java());
  1514 // we have determined that this lock/unlock can be eliminated, we simply
  1515 // eliminate the node without expanding it.
  1516 //
  1517 // Note:  The membar's associated with the lock/unlock are currently not
  1518 //        eliminated.  This should be investigated as a future enhancement.
  1519 //
  1520 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
  1522   if (!alock->is_eliminated()) {
  1523     return false;
  1525   if (alock->is_Lock() && !alock->is_coarsened()) {
  1526       // Create new "eliminated" BoxLock node and use it
  1527       // in monitor debug info for the same object.
  1528       BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
  1529       Node* obj = alock->obj_node();
  1530       if (!oldbox->is_eliminated()) {
  1531         BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
  1532         newbox->set_eliminated();
  1533         transform_later(newbox);
  1534         // Replace old box node with new box for all users
  1535         // of the same object.
  1536         for (uint i = 0; i < oldbox->outcnt();) {
  1538           bool next_edge = true;
  1539           Node* u = oldbox->raw_out(i);
  1540           if (u == alock) {
  1541             i++;
  1542             continue; // It will be removed below
  1544           if (u->is_Lock() &&
  1545               u->as_Lock()->obj_node() == obj &&
  1546               // oldbox could be referenced in debug info also
  1547               u->as_Lock()->box_node() == oldbox) {
  1548             assert(u->as_Lock()->is_eliminated(), "sanity");
  1549             _igvn.hash_delete(u);
  1550             u->set_req(TypeFunc::Parms + 1, newbox);
  1551             next_edge = false;
  1552 #ifdef ASSERT
  1553           } else if (u->is_Unlock() && u->as_Unlock()->obj_node() == obj) {
  1554             assert(u->as_Unlock()->is_eliminated(), "sanity");
  1555 #endif
  1557           // Replace old box in monitor debug info.
  1558           if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
  1559             SafePointNode* sfn = u->as_SafePoint();
  1560             JVMState* youngest_jvms = sfn->jvms();
  1561             int max_depth = youngest_jvms->depth();
  1562             for (int depth = 1; depth <= max_depth; depth++) {
  1563               JVMState* jvms = youngest_jvms->of_depth(depth);
  1564               int num_mon  = jvms->nof_monitors();
  1565               // Loop over monitors
  1566               for (int idx = 0; idx < num_mon; idx++) {
  1567                 Node* obj_node = sfn->monitor_obj(jvms, idx);
  1568                 Node* box_node = sfn->monitor_box(jvms, idx);
  1569                 if (box_node == oldbox && obj_node == obj) {
  1570                   int j = jvms->monitor_box_offset(idx);
  1571                   _igvn.hash_delete(u);
  1572                   u->set_req(j, newbox);
  1573                   next_edge = false;
  1575               } // for (int idx = 0;
  1576             } // for (int depth = 1;
  1577           } // if (u->is_SafePoint()
  1578           if (next_edge) i++;
  1579         } // for (uint i = 0; i < oldbox->outcnt();)
  1580       } // if (!oldbox->is_eliminated())
  1581   } // if (alock->is_Lock() && !lock->is_coarsened())
  1583   #ifndef PRODUCT
  1584   if (PrintEliminateLocks) {
  1585     if (alock->is_Lock()) {
  1586       tty->print_cr("++++ Eliminating: %d Lock", alock->_idx);
  1587     } else {
  1588       tty->print_cr("++++ Eliminating: %d Unlock", alock->_idx);
  1591   #endif
  1593   Node* mem  = alock->in(TypeFunc::Memory);
  1594   Node* ctrl = alock->in(TypeFunc::Control);
  1596   extract_call_projections(alock);
  1597   // There are 2 projections from the lock.  The lock node will
  1598   // be deleted when its last use is subsumed below.
  1599   assert(alock->outcnt() == 2 &&
  1600          _fallthroughproj != NULL &&
  1601          _memproj_fallthrough != NULL,
  1602          "Unexpected projections from Lock/Unlock");
  1604   Node* fallthroughproj = _fallthroughproj;
  1605   Node* memproj_fallthrough = _memproj_fallthrough;
  1607   // The memory projection from a lock/unlock is RawMem
  1608   // The input to a Lock is merged memory, so extract its RawMem input
  1609   // (unless the MergeMem has been optimized away.)
  1610   if (alock->is_Lock()) {
  1611     // Seach for MemBarAcquire node and delete it also.
  1612     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
  1613     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquire, "");
  1614     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
  1615     Node* memproj = membar->proj_out(TypeFunc::Memory);
  1616     _igvn.hash_delete(ctrlproj);
  1617     _igvn.subsume_node(ctrlproj, fallthroughproj);
  1618     _igvn.hash_delete(memproj);
  1619     _igvn.subsume_node(memproj, memproj_fallthrough);
  1621     // Delete FastLock node also if this Lock node is unique user
  1622     // (a loop peeling may clone a Lock node).
  1623     Node* flock = alock->as_Lock()->fastlock_node();
  1624     if (flock->outcnt() == 1) {
  1625       assert(flock->unique_out() == alock, "sanity");
  1626       _igvn.hash_delete(flock);
  1627       _igvn.subsume_node(flock, top());
  1631   // Seach for MemBarRelease node and delete it also.
  1632   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
  1633       ctrl->in(0)->is_MemBar()) {
  1634     MemBarNode* membar = ctrl->in(0)->as_MemBar();
  1635     assert(membar->Opcode() == Op_MemBarRelease &&
  1636            mem->is_Proj() && membar == mem->in(0), "");
  1637     _igvn.hash_delete(fallthroughproj);
  1638     _igvn.subsume_node(fallthroughproj, ctrl);
  1639     _igvn.hash_delete(memproj_fallthrough);
  1640     _igvn.subsume_node(memproj_fallthrough, mem);
  1641     fallthroughproj = ctrl;
  1642     memproj_fallthrough = mem;
  1643     ctrl = membar->in(TypeFunc::Control);
  1644     mem  = membar->in(TypeFunc::Memory);
  1647   _igvn.hash_delete(fallthroughproj);
  1648   _igvn.subsume_node(fallthroughproj, ctrl);
  1649   _igvn.hash_delete(memproj_fallthrough);
  1650   _igvn.subsume_node(memproj_fallthrough, mem);
  1651   return true;
  1655 //------------------------------expand_lock_node----------------------
  1656 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
  1658   Node* ctrl = lock->in(TypeFunc::Control);
  1659   Node* mem = lock->in(TypeFunc::Memory);
  1660   Node* obj = lock->obj_node();
  1661   Node* box = lock->box_node();
  1662   Node* flock = lock->fastlock_node();
  1664   // Make the merge point
  1665   Node *region;
  1666   Node *mem_phi;
  1667   Node *slow_path;
  1669   if (UseOptoBiasInlining) {
  1670     /*
  1671      *  See the full description in MacroAssembler::biased_locking_enter().
  1673      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
  1674      *    // The object is biased.
  1675      *    proto_node = klass->prototype_header;
  1676      *    o_node = thread | proto_node;
  1677      *    x_node = o_node ^ mark_word;
  1678      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
  1679      *      // Done.
  1680      *    } else {
  1681      *      if( (x_node & biased_lock_mask) != 0 ) {
  1682      *        // The klass's prototype header is no longer biased.
  1683      *        cas(&mark_word, mark_word, proto_node)
  1684      *        goto cas_lock;
  1685      *      } else {
  1686      *        // The klass's prototype header is still biased.
  1687      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
  1688      *          old = mark_word;
  1689      *          new = o_node;
  1690      *        } else {
  1691      *          // Different thread or anonymous biased.
  1692      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
  1693      *          new = thread | old;
  1694      *        }
  1695      *        // Try to rebias.
  1696      *        if( cas(&mark_word, old, new) == 0 ) {
  1697      *          // Done.
  1698      *        } else {
  1699      *          goto slow_path; // Failed.
  1700      *        }
  1701      *      }
  1702      *    }
  1703      *  } else {
  1704      *    // The object is not biased.
  1705      *    cas_lock:
  1706      *    if( FastLock(obj) == 0 ) {
  1707      *      // Done.
  1708      *    } else {
  1709      *      slow_path:
  1710      *      OptoRuntime::complete_monitor_locking_Java(obj);
  1711      *    }
  1712      *  }
  1713      */
  1715     region  = new (C, 5) RegionNode(5);
  1716     // create a Phi for the memory state
  1717     mem_phi = new (C, 5) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1719     Node* fast_lock_region  = new (C, 3) RegionNode(3);
  1720     Node* fast_lock_mem_phi = new (C, 3) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1722     // First, check mark word for the biased lock pattern.
  1723     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  1725     // Get fast path - mark word has the biased lock pattern.
  1726     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
  1727                          markOopDesc::biased_lock_mask_in_place,
  1728                          markOopDesc::biased_lock_pattern, true);
  1729     // fast_lock_region->in(1) is set to slow path.
  1730     fast_lock_mem_phi->init_req(1, mem);
  1732     // Now check that the lock is biased to the current thread and has
  1733     // the same epoch and bias as Klass::_prototype_header.
  1735     // Special-case a fresh allocation to avoid building nodes:
  1736     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
  1737     if (klass_node == NULL) {
  1738       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
  1739       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
  1740 #ifdef _LP64
  1741       if (UseCompressedOops && klass_node->is_DecodeN()) {
  1742         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
  1743         klass_node->in(1)->init_req(0, ctrl);
  1744       } else
  1745 #endif
  1746       klass_node->init_req(0, ctrl);
  1748     Node *proto_node = make_load(ctrl, mem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeX_X, TypeX_X->basic_type());
  1750     Node* thread = transform_later(new (C, 1) ThreadLocalNode());
  1751     Node* cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
  1752     Node* o_node = transform_later(new (C, 3) OrXNode(cast_thread, proto_node));
  1753     Node* x_node = transform_later(new (C, 3) XorXNode(o_node, mark_node));
  1755     // Get slow path - mark word does NOT match the value.
  1756     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
  1757                                       (~markOopDesc::age_mask_in_place), 0);
  1758     // region->in(3) is set to fast path - the object is biased to the current thread.
  1759     mem_phi->init_req(3, mem);
  1762     // Mark word does NOT match the value (thread | Klass::_prototype_header).
  1765     // First, check biased pattern.
  1766     // Get fast path - _prototype_header has the same biased lock pattern.
  1767     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
  1768                           markOopDesc::biased_lock_mask_in_place, 0, true);
  1770     not_biased_ctrl = fast_lock_region->in(2); // Slow path
  1771     // fast_lock_region->in(2) - the prototype header is no longer biased
  1772     // and we have to revoke the bias on this object.
  1773     // We are going to try to reset the mark of this object to the prototype
  1774     // value and fall through to the CAS-based locking scheme.
  1775     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
  1776     Node* cas = new (C, 5) StoreXConditionalNode(not_biased_ctrl, mem, adr,
  1777                                                  proto_node, mark_node);
  1778     transform_later(cas);
  1779     Node* proj = transform_later( new (C, 1) SCMemProjNode(cas));
  1780     fast_lock_mem_phi->init_req(2, proj);
  1783     // Second, check epoch bits.
  1784     Node* rebiased_region  = new (C, 3) RegionNode(3);
  1785     Node* old_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
  1786     Node* new_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
  1788     // Get slow path - mark word does NOT match epoch bits.
  1789     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
  1790                                       markOopDesc::epoch_mask_in_place, 0);
  1791     // The epoch of the current bias is not valid, attempt to rebias the object
  1792     // toward the current thread.
  1793     rebiased_region->init_req(2, epoch_ctrl);
  1794     old_phi->init_req(2, mark_node);
  1795     new_phi->init_req(2, o_node);
  1797     // rebiased_region->in(1) is set to fast path.
  1798     // The epoch of the current bias is still valid but we know
  1799     // nothing about the owner; it might be set or it might be clear.
  1800     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
  1801                              markOopDesc::age_mask_in_place |
  1802                              markOopDesc::epoch_mask_in_place);
  1803     Node* old = transform_later(new (C, 3) AndXNode(mark_node, cmask));
  1804     cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
  1805     Node* new_mark = transform_later(new (C, 3) OrXNode(cast_thread, old));
  1806     old_phi->init_req(1, old);
  1807     new_phi->init_req(1, new_mark);
  1809     transform_later(rebiased_region);
  1810     transform_later(old_phi);
  1811     transform_later(new_phi);
  1813     // Try to acquire the bias of the object using an atomic operation.
  1814     // If this fails we will go in to the runtime to revoke the object's bias.
  1815     cas = new (C, 5) StoreXConditionalNode(rebiased_region, mem, adr,
  1816                                            new_phi, old_phi);
  1817     transform_later(cas);
  1818     proj = transform_later( new (C, 1) SCMemProjNode(cas));
  1820     // Get slow path - Failed to CAS.
  1821     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
  1822     mem_phi->init_req(4, proj);
  1823     // region->in(4) is set to fast path - the object is rebiased to the current thread.
  1825     // Failed to CAS.
  1826     slow_path  = new (C, 3) RegionNode(3);
  1827     Node *slow_mem = new (C, 3) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
  1829     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
  1830     slow_mem->init_req(1, proj);
  1832     // Call CAS-based locking scheme (FastLock node).
  1834     transform_later(fast_lock_region);
  1835     transform_later(fast_lock_mem_phi);
  1837     // Get slow path - FastLock failed to lock the object.
  1838     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
  1839     mem_phi->init_req(2, fast_lock_mem_phi);
  1840     // region->in(2) is set to fast path - the object is locked to the current thread.
  1842     slow_path->init_req(2, ctrl); // Capture slow-control
  1843     slow_mem->init_req(2, fast_lock_mem_phi);
  1845     transform_later(slow_path);
  1846     transform_later(slow_mem);
  1847     // Reset lock's memory edge.
  1848     lock->set_req(TypeFunc::Memory, slow_mem);
  1850   } else {
  1851     region  = new (C, 3) RegionNode(3);
  1852     // create a Phi for the memory state
  1853     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1855     // Optimize test; set region slot 2
  1856     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
  1857     mem_phi->init_req(2, mem);
  1860   // Make slow path call
  1861   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
  1863   extract_call_projections(call);
  1865   // Slow path can only throw asynchronous exceptions, which are always
  1866   // de-opted.  So the compiler thinks the slow-call can never throw an
  1867   // exception.  If it DOES throw an exception we would need the debug
  1868   // info removed first (since if it throws there is no monitor).
  1869   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  1870            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  1872   // Capture slow path
  1873   // disconnect fall-through projection from call and create a new one
  1874   // hook up users of fall-through projection to region
  1875   Node *slow_ctrl = _fallthroughproj->clone();
  1876   transform_later(slow_ctrl);
  1877   _igvn.hash_delete(_fallthroughproj);
  1878   _fallthroughproj->disconnect_inputs(NULL);
  1879   region->init_req(1, slow_ctrl);
  1880   // region inputs are now complete
  1881   transform_later(region);
  1882   _igvn.subsume_node(_fallthroughproj, region);
  1884   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
  1885   mem_phi->init_req(1, memproj );
  1886   transform_later(mem_phi);
  1887   _igvn.hash_delete(_memproj_fallthrough);
  1888   _igvn.subsume_node(_memproj_fallthrough, mem_phi);
  1891 //------------------------------expand_unlock_node----------------------
  1892 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
  1894   Node* ctrl = unlock->in(TypeFunc::Control);
  1895   Node* mem = unlock->in(TypeFunc::Memory);
  1896   Node* obj = unlock->obj_node();
  1897   Node* box = unlock->box_node();
  1899   // No need for a null check on unlock
  1901   // Make the merge point
  1902   Node *region;
  1903   Node *mem_phi;
  1905   if (UseOptoBiasInlining) {
  1906     // Check for biased locking unlock case, which is a no-op.
  1907     // See the full description in MacroAssembler::biased_locking_exit().
  1908     region  = new (C, 4) RegionNode(4);
  1909     // create a Phi for the memory state
  1910     mem_phi = new (C, 4) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1911     mem_phi->init_req(3, mem);
  1913     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  1914     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
  1915                          markOopDesc::biased_lock_mask_in_place,
  1916                          markOopDesc::biased_lock_pattern);
  1917   } else {
  1918     region  = new (C, 3) RegionNode(3);
  1919     // create a Phi for the memory state
  1920     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1923   FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box );
  1924   funlock = transform_later( funlock )->as_FastUnlock();
  1925   // Optimize test; set region slot 2
  1926   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
  1928   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 );
  1930   extract_call_projections(call);
  1932   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  1933            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  1935   // No exceptions for unlocking
  1936   // Capture slow path
  1937   // disconnect fall-through projection from call and create a new one
  1938   // hook up users of fall-through projection to region
  1939   Node *slow_ctrl = _fallthroughproj->clone();
  1940   transform_later(slow_ctrl);
  1941   _igvn.hash_delete(_fallthroughproj);
  1942   _fallthroughproj->disconnect_inputs(NULL);
  1943   region->init_req(1, slow_ctrl);
  1944   // region inputs are now complete
  1945   transform_later(region);
  1946   _igvn.subsume_node(_fallthroughproj, region);
  1948   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
  1949   mem_phi->init_req(1, memproj );
  1950   mem_phi->init_req(2, mem);
  1951   transform_later(mem_phi);
  1952   _igvn.hash_delete(_memproj_fallthrough);
  1953   _igvn.subsume_node(_memproj_fallthrough, mem_phi);
  1956 //------------------------------expand_macro_nodes----------------------
  1957 //  Returns true if a failure occurred.
  1958 bool PhaseMacroExpand::expand_macro_nodes() {
  1959   if (C->macro_count() == 0)
  1960     return false;
  1961   // First, attempt to eliminate locks
  1962   bool progress = true;
  1963   while (progress) {
  1964     progress = false;
  1965     for (int i = C->macro_count(); i > 0; i--) {
  1966       Node * n = C->macro_node(i-1);
  1967       bool success = false;
  1968       debug_only(int old_macro_count = C->macro_count(););
  1969       if (n->is_AbstractLock()) {
  1970         success = eliminate_locking_node(n->as_AbstractLock());
  1971       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
  1972         _igvn.add_users_to_worklist(n);
  1973         _igvn.hash_delete(n);
  1974         _igvn.subsume_node(n, n->in(1));
  1975         success = true;
  1977       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  1978       progress = progress || success;
  1981   // Next, attempt to eliminate allocations
  1982   progress = true;
  1983   while (progress) {
  1984     progress = false;
  1985     for (int i = C->macro_count(); i > 0; i--) {
  1986       Node * n = C->macro_node(i-1);
  1987       bool success = false;
  1988       debug_only(int old_macro_count = C->macro_count(););
  1989       switch (n->class_id()) {
  1990       case Node::Class_Allocate:
  1991       case Node::Class_AllocateArray:
  1992         success = eliminate_allocate_node(n->as_Allocate());
  1993         break;
  1994       case Node::Class_Lock:
  1995       case Node::Class_Unlock:
  1996         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
  1997         break;
  1998       default:
  1999         assert(false, "unknown node type in macro list");
  2001       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2002       progress = progress || success;
  2005   // Make sure expansion will not cause node limit to be exceeded.
  2006   // Worst case is a macro node gets expanded into about 50 nodes.
  2007   // Allow 50% more for optimization.
  2008   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
  2009     return true;
  2011   // expand "macro" nodes
  2012   // nodes are removed from the macro list as they are processed
  2013   while (C->macro_count() > 0) {
  2014     int macro_count = C->macro_count();
  2015     Node * n = C->macro_node(macro_count-1);
  2016     assert(n->is_macro(), "only macro nodes expected here");
  2017     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
  2018       // node is unreachable, so don't try to expand it
  2019       C->remove_macro_node(n);
  2020       continue;
  2022     switch (n->class_id()) {
  2023     case Node::Class_Allocate:
  2024       expand_allocate(n->as_Allocate());
  2025       break;
  2026     case Node::Class_AllocateArray:
  2027       expand_allocate_array(n->as_AllocateArray());
  2028       break;
  2029     case Node::Class_Lock:
  2030       expand_lock_node(n->as_Lock());
  2031       break;
  2032     case Node::Class_Unlock:
  2033       expand_unlock_node(n->as_Unlock());
  2034       break;
  2035     default:
  2036       assert(false, "unknown node type in macro list");
  2038     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
  2039     if (C->failing())  return true;
  2042   _igvn.set_delay_transform(false);
  2043   _igvn.optimize();
  2044   return false;

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