src/share/vm/opto/macro.cpp

Tue, 25 Nov 2014 17:33:59 +0100

author
roland
date
Tue, 25 Nov 2014 17:33:59 +0100
changeset 7419
d3f3f7677537
parent 7341
e7b3d177adda
child 7535
7ae4e26cb1e0
child 7605
6e8e0bf87bbe
permissions
-rw-r--r--

6898462: The escape analysis with G1 cause crash assertion src/share/vm/runtime/vframeArray.cpp:94
Summary: OOM during reallocation of scalar replaced objects in deoptimization causes crashes
Reviewed-by: kvn, jrose

     1 /*
     2  * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "compiler/compileLog.hpp"
    27 #include "libadt/vectset.hpp"
    28 #include "opto/addnode.hpp"
    29 #include "opto/callnode.hpp"
    30 #include "opto/cfgnode.hpp"
    31 #include "opto/compile.hpp"
    32 #include "opto/connode.hpp"
    33 #include "opto/locknode.hpp"
    34 #include "opto/loopnode.hpp"
    35 #include "opto/macro.hpp"
    36 #include "opto/memnode.hpp"
    37 #include "opto/node.hpp"
    38 #include "opto/phaseX.hpp"
    39 #include "opto/rootnode.hpp"
    40 #include "opto/runtime.hpp"
    41 #include "opto/subnode.hpp"
    42 #include "opto/type.hpp"
    43 #include "runtime/sharedRuntime.hpp"
    46 //
    47 // Replace any references to "oldref" in inputs to "use" with "newref".
    48 // Returns the number of replacements made.
    49 //
    50 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
    51   int nreplacements = 0;
    52   uint req = use->req();
    53   for (uint j = 0; j < use->len(); j++) {
    54     Node *uin = use->in(j);
    55     if (uin == oldref) {
    56       if (j < req)
    57         use->set_req(j, newref);
    58       else
    59         use->set_prec(j, newref);
    60       nreplacements++;
    61     } else if (j >= req && uin == NULL) {
    62       break;
    63     }
    64   }
    65   return nreplacements;
    66 }
    68 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
    69   // Copy debug information and adjust JVMState information
    70   uint old_dbg_start = oldcall->tf()->domain()->cnt();
    71   uint new_dbg_start = newcall->tf()->domain()->cnt();
    72   int jvms_adj  = new_dbg_start - old_dbg_start;
    73   assert (new_dbg_start == newcall->req(), "argument count mismatch");
    75   // SafePointScalarObject node could be referenced several times in debug info.
    76   // Use Dict to record cloned nodes.
    77   Dict* sosn_map = new Dict(cmpkey,hashkey);
    78   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
    79     Node* old_in = oldcall->in(i);
    80     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
    81     if (old_in != NULL && old_in->is_SafePointScalarObject()) {
    82       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
    83       uint old_unique = C->unique();
    84       Node* new_in = old_sosn->clone(sosn_map);
    85       if (old_unique != C->unique()) { // New node?
    86         new_in->set_req(0, C->root()); // reset control edge
    87         new_in = transform_later(new_in); // Register new node.
    88       }
    89       old_in = new_in;
    90     }
    91     newcall->add_req(old_in);
    92   }
    94   newcall->set_jvms(oldcall->jvms());
    95   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
    96     jvms->set_map(newcall);
    97     jvms->set_locoff(jvms->locoff()+jvms_adj);
    98     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
    99     jvms->set_monoff(jvms->monoff()+jvms_adj);
   100     jvms->set_scloff(jvms->scloff()+jvms_adj);
   101     jvms->set_endoff(jvms->endoff()+jvms_adj);
   102   }
   103 }
   105 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
   106   Node* cmp;
   107   if (mask != 0) {
   108     Node* and_node = transform_later(new (C) AndXNode(word, MakeConX(mask)));
   109     cmp = transform_later(new (C) CmpXNode(and_node, MakeConX(bits)));
   110   } else {
   111     cmp = word;
   112   }
   113   Node* bol = transform_later(new (C) BoolNode(cmp, BoolTest::ne));
   114   IfNode* iff = new (C) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
   115   transform_later(iff);
   117   // Fast path taken.
   118   Node *fast_taken = transform_later( new (C) IfFalseNode(iff) );
   120   // Fast path not-taken, i.e. slow path
   121   Node *slow_taken = transform_later( new (C) IfTrueNode(iff) );
   123   if (return_fast_path) {
   124     region->init_req(edge, slow_taken); // Capture slow-control
   125     return fast_taken;
   126   } else {
   127     region->init_req(edge, fast_taken); // Capture fast-control
   128     return slow_taken;
   129   }
   130 }
   132 //--------------------copy_predefined_input_for_runtime_call--------------------
   133 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
   134   // Set fixed predefined input arguments
   135   call->init_req( TypeFunc::Control, ctrl );
   136   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
   137   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
   138   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
   139   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
   140 }
   142 //------------------------------make_slow_call---------------------------------
   143 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) {
   145   // Slow-path call
   146  CallNode *call = leaf_name
   147    ? (CallNode*)new (C) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
   148    : (CallNode*)new (C) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
   150   // Slow path call has no side-effects, uses few values
   151   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
   152   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
   153   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
   154   copy_call_debug_info(oldcall, call);
   155   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
   156   _igvn.replace_node(oldcall, call);
   157   transform_later(call);
   159   return call;
   160 }
   162 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
   163   _fallthroughproj = NULL;
   164   _fallthroughcatchproj = NULL;
   165   _ioproj_fallthrough = NULL;
   166   _ioproj_catchall = NULL;
   167   _catchallcatchproj = NULL;
   168   _memproj_fallthrough = NULL;
   169   _memproj_catchall = NULL;
   170   _resproj = NULL;
   171   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
   172     ProjNode *pn = call->fast_out(i)->as_Proj();
   173     switch (pn->_con) {
   174       case TypeFunc::Control:
   175       {
   176         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
   177         _fallthroughproj = pn;
   178         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
   179         const Node *cn = pn->fast_out(j);
   180         if (cn->is_Catch()) {
   181           ProjNode *cpn = NULL;
   182           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
   183             cpn = cn->fast_out(k)->as_Proj();
   184             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
   185             if (cpn->_con == CatchProjNode::fall_through_index)
   186               _fallthroughcatchproj = cpn;
   187             else {
   188               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
   189               _catchallcatchproj = cpn;
   190             }
   191           }
   192         }
   193         break;
   194       }
   195       case TypeFunc::I_O:
   196         if (pn->_is_io_use)
   197           _ioproj_catchall = pn;
   198         else
   199           _ioproj_fallthrough = pn;
   200         break;
   201       case TypeFunc::Memory:
   202         if (pn->_is_io_use)
   203           _memproj_catchall = pn;
   204         else
   205           _memproj_fallthrough = pn;
   206         break;
   207       case TypeFunc::Parms:
   208         _resproj = pn;
   209         break;
   210       default:
   211         assert(false, "unexpected projection from allocation node.");
   212     }
   213   }
   215 }
   217 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
   218 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
   219   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
   220   if (!UseG1GC) {
   221     // vanilla/CMS post barrier
   222     Node *shift = p2x->unique_out();
   223     Node *addp = shift->unique_out();
   224     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
   225       Node *mem = addp->last_out(j);
   226       if (UseCondCardMark && mem->is_Load()) {
   227         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
   228         // The load is checking if the card has been written so
   229         // replace it with zero to fold the test.
   230         _igvn.replace_node(mem, intcon(0));
   231         continue;
   232       }
   233       assert(mem->is_Store(), "store required");
   234       _igvn.replace_node(mem, mem->in(MemNode::Memory));
   235     }
   236   } else {
   237     // G1 pre/post barriers
   238     assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
   239     // It could be only one user, URShift node, in Object.clone() instrinsic
   240     // but the new allocation is passed to arraycopy stub and it could not
   241     // be scalar replaced. So we don't check the case.
   243     // An other case of only one user (Xor) is when the value check for NULL
   244     // in G1 post barrier is folded after CCP so the code which used URShift
   245     // is removed.
   247     // Take Region node before eliminating post barrier since it also
   248     // eliminates CastP2X node when it has only one user.
   249     Node* this_region = p2x->in(0);
   250     assert(this_region != NULL, "");
   252     // Remove G1 post barrier.
   254     // Search for CastP2X->Xor->URShift->Cmp path which
   255     // checks if the store done to a different from the value's region.
   256     // And replace Cmp with #0 (false) to collapse G1 post barrier.
   257     Node* xorx = NULL;
   258     for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
   259       Node* u = p2x->fast_out(i);
   260       if (u->Opcode() == Op_XorX) {
   261         xorx = u;
   262         break;
   263       }
   264     }
   265     assert(xorx != NULL, "missing G1 post barrier");
   266     Node* shift = xorx->unique_out();
   267     Node* cmpx = shift->unique_out();
   268     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
   269     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
   270     "missing region check in G1 post barrier");
   271     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
   273     // Remove G1 pre barrier.
   275     // Search "if (marking != 0)" check and set it to "false".
   276     // There is no G1 pre barrier if previous stored value is NULL
   277     // (for example, after initialization).
   278     if (this_region->is_Region() && this_region->req() == 3) {
   279       int ind = 1;
   280       if (!this_region->in(ind)->is_IfFalse()) {
   281         ind = 2;
   282       }
   283       if (this_region->in(ind)->is_IfFalse()) {
   284         Node* bol = this_region->in(ind)->in(0)->in(1);
   285         assert(bol->is_Bool(), "");
   286         cmpx = bol->in(1);
   287         if (bol->as_Bool()->_test._test == BoolTest::ne &&
   288             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
   289             cmpx->in(1)->is_Load()) {
   290           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
   291           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
   292                                               PtrQueue::byte_offset_of_active());
   293           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
   294               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
   295               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
   296             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
   297           }
   298         }
   299       }
   300     }
   301     // Now CastP2X can be removed since it is used only on dead path
   302     // which currently still alive until igvn optimize it.
   303     assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
   304     _igvn.replace_node(p2x, top());
   305   }
   306 }
   308 // Search for a memory operation for the specified memory slice.
   309 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
   310   Node *orig_mem = mem;
   311   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   312   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
   313   while (true) {
   314     if (mem == alloc_mem || mem == start_mem ) {
   315       return mem;  // hit one of our sentinels
   316     } else if (mem->is_MergeMem()) {
   317       mem = mem->as_MergeMem()->memory_at(alias_idx);
   318     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
   319       Node *in = mem->in(0);
   320       // we can safely skip over safepoints, calls, locks and membars because we
   321       // already know that the object is safe to eliminate.
   322       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
   323         return in;
   324       } else if (in->is_Call()) {
   325         CallNode *call = in->as_Call();
   326         if (!call->may_modify(tinst, phase)) {
   327           mem = call->in(TypeFunc::Memory);
   328         }
   329         mem = in->in(TypeFunc::Memory);
   330       } else if (in->is_MemBar()) {
   331         mem = in->in(TypeFunc::Memory);
   332       } else {
   333         assert(false, "unexpected projection");
   334       }
   335     } else if (mem->is_Store()) {
   336       const TypePtr* atype = mem->as_Store()->adr_type();
   337       int adr_idx = Compile::current()->get_alias_index(atype);
   338       if (adr_idx == alias_idx) {
   339         assert(atype->isa_oopptr(), "address type must be oopptr");
   340         int adr_offset = atype->offset();
   341         uint adr_iid = atype->is_oopptr()->instance_id();
   342         // Array elements references have the same alias_idx
   343         // but different offset and different instance_id.
   344         if (adr_offset == offset && adr_iid == alloc->_idx)
   345           return mem;
   346       } else {
   347         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
   348       }
   349       mem = mem->in(MemNode::Memory);
   350     } else if (mem->is_ClearArray()) {
   351       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
   352         // Can not bypass initialization of the instance
   353         // we are looking.
   354         debug_only(intptr_t offset;)
   355         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
   356         InitializeNode* init = alloc->as_Allocate()->initialization();
   357         // We are looking for stored value, return Initialize node
   358         // or memory edge from Allocate node.
   359         if (init != NULL)
   360           return init;
   361         else
   362           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
   363       }
   364       // Otherwise skip it (the call updated 'mem' value).
   365     } else if (mem->Opcode() == Op_SCMemProj) {
   366       mem = mem->in(0);
   367       Node* adr = NULL;
   368       if (mem->is_LoadStore()) {
   369         adr = mem->in(MemNode::Address);
   370       } else {
   371         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
   372         adr = mem->in(3); // Destination array
   373       }
   374       const TypePtr* atype = adr->bottom_type()->is_ptr();
   375       int adr_idx = Compile::current()->get_alias_index(atype);
   376       if (adr_idx == alias_idx) {
   377         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
   378         return NULL;
   379       }
   380       mem = mem->in(MemNode::Memory);
   381     } else {
   382       return mem;
   383     }
   384     assert(mem != orig_mem, "dead memory loop");
   385   }
   386 }
   388 //
   389 // Given a Memory Phi, compute a value Phi containing the values from stores
   390 // on the input paths.
   391 // Note: this function is recursive, its depth is limied by the "level" argument
   392 // Returns the computed Phi, or NULL if it cannot compute it.
   393 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) {
   394   assert(mem->is_Phi(), "sanity");
   395   int alias_idx = C->get_alias_index(adr_t);
   396   int offset = adr_t->offset();
   397   int instance_id = adr_t->instance_id();
   399   // Check if an appropriate value phi already exists.
   400   Node* region = mem->in(0);
   401   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
   402     Node* phi = region->fast_out(k);
   403     if (phi->is_Phi() && phi != mem &&
   404         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
   405       return phi;
   406     }
   407   }
   408   // Check if an appropriate new value phi already exists.
   409   Node* new_phi = value_phis->find(mem->_idx);
   410   if (new_phi != NULL)
   411     return new_phi;
   413   if (level <= 0) {
   414     return NULL; // Give up: phi tree too deep
   415   }
   416   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   417   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   419   uint length = mem->req();
   420   GrowableArray <Node *> values(length, length, NULL, false);
   422   // create a new Phi for the value
   423   PhiNode *phi = new (C) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
   424   transform_later(phi);
   425   value_phis->push(phi, mem->_idx);
   427   for (uint j = 1; j < length; j++) {
   428     Node *in = mem->in(j);
   429     if (in == NULL || in->is_top()) {
   430       values.at_put(j, in);
   431     } else  {
   432       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
   433       if (val == start_mem || val == alloc_mem) {
   434         // hit a sentinel, return appropriate 0 value
   435         values.at_put(j, _igvn.zerocon(ft));
   436         continue;
   437       }
   438       if (val->is_Initialize()) {
   439         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   440       }
   441       if (val == NULL) {
   442         return NULL;  // can't find a value on this path
   443       }
   444       if (val == mem) {
   445         values.at_put(j, mem);
   446       } else if (val->is_Store()) {
   447         values.at_put(j, val->in(MemNode::ValueIn));
   448       } else if(val->is_Proj() && val->in(0) == alloc) {
   449         values.at_put(j, _igvn.zerocon(ft));
   450       } else if (val->is_Phi()) {
   451         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
   452         if (val == NULL) {
   453           return NULL;
   454         }
   455         values.at_put(j, val);
   456       } else if (val->Opcode() == Op_SCMemProj) {
   457         assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
   458         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
   459         return NULL;
   460       } else {
   461 #ifdef ASSERT
   462         val->dump();
   463         assert(false, "unknown node on this path");
   464 #endif
   465         return NULL;  // unknown node on this path
   466       }
   467     }
   468   }
   469   // Set Phi's inputs
   470   for (uint j = 1; j < length; j++) {
   471     if (values.at(j) == mem) {
   472       phi->init_req(j, phi);
   473     } else {
   474       phi->init_req(j, values.at(j));
   475     }
   476   }
   477   return phi;
   478 }
   480 // Search the last value stored into the object's field.
   481 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
   482   assert(adr_t->is_known_instance_field(), "instance required");
   483   int instance_id = adr_t->instance_id();
   484   assert((uint)instance_id == alloc->_idx, "wrong allocation");
   486   int alias_idx = C->get_alias_index(adr_t);
   487   int offset = adr_t->offset();
   488   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   489   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
   490   Node *alloc_mem = alloc->in(TypeFunc::Memory);
   491   Arena *a = Thread::current()->resource_area();
   492   VectorSet visited(a);
   495   bool done = sfpt_mem == alloc_mem;
   496   Node *mem = sfpt_mem;
   497   while (!done) {
   498     if (visited.test_set(mem->_idx)) {
   499       return NULL;  // found a loop, give up
   500     }
   501     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
   502     if (mem == start_mem || mem == alloc_mem) {
   503       done = true;  // hit a sentinel, return appropriate 0 value
   504     } else if (mem->is_Initialize()) {
   505       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
   506       if (mem == NULL) {
   507         done = true; // Something go wrong.
   508       } else if (mem->is_Store()) {
   509         const TypePtr* atype = mem->as_Store()->adr_type();
   510         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
   511         done = true;
   512       }
   513     } else if (mem->is_Store()) {
   514       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
   515       assert(atype != NULL, "address type must be oopptr");
   516       assert(C->get_alias_index(atype) == alias_idx &&
   517              atype->is_known_instance_field() && atype->offset() == offset &&
   518              atype->instance_id() == instance_id, "store is correct memory slice");
   519       done = true;
   520     } else if (mem->is_Phi()) {
   521       // try to find a phi's unique input
   522       Node *unique_input = NULL;
   523       Node *top = C->top();
   524       for (uint i = 1; i < mem->req(); i++) {
   525         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
   526         if (n == NULL || n == top || n == mem) {
   527           continue;
   528         } else if (unique_input == NULL) {
   529           unique_input = n;
   530         } else if (unique_input != n) {
   531           unique_input = top;
   532           break;
   533         }
   534       }
   535       if (unique_input != NULL && unique_input != top) {
   536         mem = unique_input;
   537       } else {
   538         done = true;
   539       }
   540     } else {
   541       assert(false, "unexpected node");
   542     }
   543   }
   544   if (mem != NULL) {
   545     if (mem == start_mem || mem == alloc_mem) {
   546       // hit a sentinel, return appropriate 0 value
   547       return _igvn.zerocon(ft);
   548     } else if (mem->is_Store()) {
   549       return mem->in(MemNode::ValueIn);
   550     } else if (mem->is_Phi()) {
   551       // attempt to produce a Phi reflecting the values on the input paths of the Phi
   552       Node_Stack value_phis(a, 8);
   553       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
   554       if (phi != NULL) {
   555         return phi;
   556       } else {
   557         // Kill all new Phis
   558         while(value_phis.is_nonempty()) {
   559           Node* n = value_phis.node();
   560           _igvn.replace_node(n, C->top());
   561           value_phis.pop();
   562         }
   563       }
   564     }
   565   }
   566   // Something go wrong.
   567   return NULL;
   568 }
   570 // Check the possibility of scalar replacement.
   571 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   572   //  Scan the uses of the allocation to check for anything that would
   573   //  prevent us from eliminating it.
   574   NOT_PRODUCT( const char* fail_eliminate = NULL; )
   575   DEBUG_ONLY( Node* disq_node = NULL; )
   576   bool  can_eliminate = true;
   578   Node* res = alloc->result_cast();
   579   const TypeOopPtr* res_type = NULL;
   580   if (res == NULL) {
   581     // All users were eliminated.
   582   } else if (!res->is_CheckCastPP()) {
   583     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
   584     can_eliminate = false;
   585   } else {
   586     res_type = _igvn.type(res)->isa_oopptr();
   587     if (res_type == NULL) {
   588       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
   589       can_eliminate = false;
   590     } else if (res_type->isa_aryptr()) {
   591       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   592       if (length < 0) {
   593         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
   594         can_eliminate = false;
   595       }
   596     }
   597   }
   599   if (can_eliminate && res != NULL) {
   600     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
   601                                j < jmax && can_eliminate; j++) {
   602       Node* use = res->fast_out(j);
   604       if (use->is_AddP()) {
   605         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
   606         int offset = addp_type->offset();
   608         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
   609           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
   610           can_eliminate = false;
   611           break;
   612         }
   613         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
   614                                    k < kmax && can_eliminate; k++) {
   615           Node* n = use->fast_out(k);
   616           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
   617             DEBUG_ONLY(disq_node = n;)
   618             if (n->is_Load() || n->is_LoadStore()) {
   619               NOT_PRODUCT(fail_eliminate = "Field load";)
   620             } else {
   621               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
   622             }
   623             can_eliminate = false;
   624           }
   625         }
   626       } else if (use->is_SafePoint()) {
   627         SafePointNode* sfpt = use->as_SafePoint();
   628         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
   629           // Object is passed as argument.
   630           DEBUG_ONLY(disq_node = use;)
   631           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
   632           can_eliminate = false;
   633         }
   634         Node* sfptMem = sfpt->memory();
   635         if (sfptMem == NULL || sfptMem->is_top()) {
   636           DEBUG_ONLY(disq_node = use;)
   637           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
   638           can_eliminate = false;
   639         } else {
   640           safepoints.append_if_missing(sfpt);
   641         }
   642       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
   643         if (use->is_Phi()) {
   644           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
   645             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   646           } else {
   647             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
   648           }
   649           DEBUG_ONLY(disq_node = use;)
   650         } else {
   651           if (use->Opcode() == Op_Return) {
   652             NOT_PRODUCT(fail_eliminate = "Object is return value";)
   653           }else {
   654             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
   655           }
   656           DEBUG_ONLY(disq_node = use;)
   657         }
   658         can_eliminate = false;
   659       }
   660     }
   661   }
   663 #ifndef PRODUCT
   664   if (PrintEliminateAllocations) {
   665     if (can_eliminate) {
   666       tty->print("Scalar ");
   667       if (res == NULL)
   668         alloc->dump();
   669       else
   670         res->dump();
   671     } else if (alloc->_is_scalar_replaceable) {
   672       tty->print("NotScalar (%s)", fail_eliminate);
   673       if (res == NULL)
   674         alloc->dump();
   675       else
   676         res->dump();
   677 #ifdef ASSERT
   678       if (disq_node != NULL) {
   679           tty->print("  >>>> ");
   680           disq_node->dump();
   681       }
   682 #endif /*ASSERT*/
   683     }
   684   }
   685 #endif
   686   return can_eliminate;
   687 }
   689 // Do scalar replacement.
   690 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
   691   GrowableArray <SafePointNode *> safepoints_done;
   693   ciKlass* klass = NULL;
   694   ciInstanceKlass* iklass = NULL;
   695   int nfields = 0;
   696   int array_base;
   697   int element_size;
   698   BasicType basic_elem_type;
   699   ciType* elem_type;
   701   Node* res = alloc->result_cast();
   702   assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result");
   703   const TypeOopPtr* res_type = NULL;
   704   if (res != NULL) { // Could be NULL when there are no users
   705     res_type = _igvn.type(res)->isa_oopptr();
   706   }
   708   if (res != NULL) {
   709     klass = res_type->klass();
   710     if (res_type->isa_instptr()) {
   711       // find the fields of the class which will be needed for safepoint debug information
   712       assert(klass->is_instance_klass(), "must be an instance klass.");
   713       iklass = klass->as_instance_klass();
   714       nfields = iklass->nof_nonstatic_fields();
   715     } else {
   716       // find the array's elements which will be needed for safepoint debug information
   717       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   718       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
   719       elem_type = klass->as_array_klass()->element_type();
   720       basic_elem_type = elem_type->basic_type();
   721       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
   722       element_size = type2aelembytes(basic_elem_type);
   723     }
   724   }
   725   //
   726   // Process the safepoint uses
   727   //
   728   while (safepoints.length() > 0) {
   729     SafePointNode* sfpt = safepoints.pop();
   730     Node* mem = sfpt->memory();
   731     assert(sfpt->jvms() != NULL, "missed JVMS");
   732     // Fields of scalar objs are referenced only at the end
   733     // of regular debuginfo at the last (youngest) JVMS.
   734     // Record relative start index.
   735     uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
   736     SafePointScalarObjectNode* sobj = new (C) SafePointScalarObjectNode(res_type,
   737 #ifdef ASSERT
   738                                                  alloc,
   739 #endif
   740                                                  first_ind, nfields);
   741     sobj->init_req(0, C->root());
   742     transform_later(sobj);
   744     // Scan object's fields adding an input to the safepoint for each field.
   745     for (int j = 0; j < nfields; j++) {
   746       intptr_t offset;
   747       ciField* field = NULL;
   748       if (iklass != NULL) {
   749         field = iklass->nonstatic_field_at(j);
   750         offset = field->offset();
   751         elem_type = field->type();
   752         basic_elem_type = field->layout_type();
   753       } else {
   754         offset = array_base + j * (intptr_t)element_size;
   755       }
   757       const Type *field_type;
   758       // The next code is taken from Parse::do_get_xxx().
   759       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
   760         if (!elem_type->is_loaded()) {
   761           field_type = TypeInstPtr::BOTTOM;
   762         } else if (field != NULL && field->is_constant() && field->is_static()) {
   763           // This can happen if the constant oop is non-perm.
   764           ciObject* con = field->constant_value().as_object();
   765           // Do not "join" in the previous type; it doesn't add value,
   766           // and may yield a vacuous result if the field is of interface type.
   767           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
   768           assert(field_type != NULL, "field singleton type must be consistent");
   769         } else {
   770           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
   771         }
   772         if (UseCompressedOops) {
   773           field_type = field_type->make_narrowoop();
   774           basic_elem_type = T_NARROWOOP;
   775         }
   776       } else {
   777         field_type = Type::get_const_basic_type(basic_elem_type);
   778       }
   780       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
   782       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
   783       if (field_val == NULL) {
   784         // We weren't able to find a value for this field,
   785         // give up on eliminating this allocation.
   787         // Remove any extra entries we added to the safepoint.
   788         uint last = sfpt->req() - 1;
   789         for (int k = 0;  k < j; k++) {
   790           sfpt->del_req(last--);
   791         }
   792         // rollback processed safepoints
   793         while (safepoints_done.length() > 0) {
   794           SafePointNode* sfpt_done = safepoints_done.pop();
   795           // remove any extra entries we added to the safepoint
   796           last = sfpt_done->req() - 1;
   797           for (int k = 0;  k < nfields; k++) {
   798             sfpt_done->del_req(last--);
   799           }
   800           JVMState *jvms = sfpt_done->jvms();
   801           jvms->set_endoff(sfpt_done->req());
   802           // Now make a pass over the debug information replacing any references
   803           // to SafePointScalarObjectNode with the allocated object.
   804           int start = jvms->debug_start();
   805           int end   = jvms->debug_end();
   806           for (int i = start; i < end; i++) {
   807             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
   808               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
   809               if (scobj->first_index(jvms) == sfpt_done->req() &&
   810                   scobj->n_fields() == (uint)nfields) {
   811                 assert(scobj->alloc() == alloc, "sanity");
   812                 sfpt_done->set_req(i, res);
   813               }
   814             }
   815           }
   816         }
   817 #ifndef PRODUCT
   818         if (PrintEliminateAllocations) {
   819           if (field != NULL) {
   820             tty->print("=== At SafePoint node %d can't find value of Field: ",
   821                        sfpt->_idx);
   822             field->print();
   823             int field_idx = C->get_alias_index(field_addr_type);
   824             tty->print(" (alias_idx=%d)", field_idx);
   825           } else { // Array's element
   826             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
   827                        sfpt->_idx, j);
   828           }
   829           tty->print(", which prevents elimination of: ");
   830           if (res == NULL)
   831             alloc->dump();
   832           else
   833             res->dump();
   834         }
   835 #endif
   836         return false;
   837       }
   838       if (UseCompressedOops && field_type->isa_narrowoop()) {
   839         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
   840         // to be able scalar replace the allocation.
   841         if (field_val->is_EncodeP()) {
   842           field_val = field_val->in(1);
   843         } else {
   844           field_val = transform_later(new (C) DecodeNNode(field_val, field_val->get_ptr_type()));
   845         }
   846       }
   847       sfpt->add_req(field_val);
   848     }
   849     JVMState *jvms = sfpt->jvms();
   850     jvms->set_endoff(sfpt->req());
   851     // Now make a pass over the debug information replacing any references
   852     // to the allocated object with "sobj"
   853     int start = jvms->debug_start();
   854     int end   = jvms->debug_end();
   855     sfpt->replace_edges_in_range(res, sobj, start, end);
   856     safepoints_done.append_if_missing(sfpt); // keep it for rollback
   857   }
   858   return true;
   859 }
   861 // Process users of eliminated allocation.
   862 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
   863   Node* res = alloc->result_cast();
   864   if (res != NULL) {
   865     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
   866       Node *use = res->last_out(j);
   867       uint oc1 = res->outcnt();
   869       if (use->is_AddP()) {
   870         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
   871           Node *n = use->last_out(k);
   872           uint oc2 = use->outcnt();
   873           if (n->is_Store()) {
   874 #ifdef ASSERT
   875             // Verify that there is no dependent MemBarVolatile nodes,
   876             // they should be removed during IGVN, see MemBarNode::Ideal().
   877             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
   878                                        p < pmax; p++) {
   879               Node* mb = n->fast_out(p);
   880               assert(mb->is_Initialize() || !mb->is_MemBar() ||
   881                      mb->req() <= MemBarNode::Precedent ||
   882                      mb->in(MemBarNode::Precedent) != n,
   883                      "MemBarVolatile should be eliminated for non-escaping object");
   884             }
   885 #endif
   886             _igvn.replace_node(n, n->in(MemNode::Memory));
   887           } else {
   888             eliminate_card_mark(n);
   889           }
   890           k -= (oc2 - use->outcnt());
   891         }
   892       } else {
   893         eliminate_card_mark(use);
   894       }
   895       j -= (oc1 - res->outcnt());
   896     }
   897     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
   898     _igvn.remove_dead_node(res);
   899   }
   901   //
   902   // Process other users of allocation's projections
   903   //
   904   if (_resproj != NULL && _resproj->outcnt() != 0) {
   905     // First disconnect stores captured by Initialize node.
   906     // If Initialize node is eliminated first in the following code,
   907     // it will kill such stores and DUIterator_Last will assert.
   908     for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax);  j < jmax; j++) {
   909       Node *use = _resproj->fast_out(j);
   910       if (use->is_AddP()) {
   911         // raw memory addresses used only by the initialization
   912         _igvn.replace_node(use, C->top());
   913         --j; --jmax;
   914       }
   915     }
   916     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
   917       Node *use = _resproj->last_out(j);
   918       uint oc1 = _resproj->outcnt();
   919       if (use->is_Initialize()) {
   920         // Eliminate Initialize node.
   921         InitializeNode *init = use->as_Initialize();
   922         assert(init->outcnt() <= 2, "only a control and memory projection expected");
   923         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
   924         if (ctrl_proj != NULL) {
   925            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
   926           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
   927         }
   928         Node *mem_proj = init->proj_out(TypeFunc::Memory);
   929         if (mem_proj != NULL) {
   930           Node *mem = init->in(TypeFunc::Memory);
   931 #ifdef ASSERT
   932           if (mem->is_MergeMem()) {
   933             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
   934           } else {
   935             assert(mem == _memproj_fallthrough, "allocation memory projection");
   936           }
   937 #endif
   938           _igvn.replace_node(mem_proj, mem);
   939         }
   940       } else  {
   941         assert(false, "only Initialize or AddP expected");
   942       }
   943       j -= (oc1 - _resproj->outcnt());
   944     }
   945   }
   946   if (_fallthroughcatchproj != NULL) {
   947     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
   948   }
   949   if (_memproj_fallthrough != NULL) {
   950     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
   951   }
   952   if (_memproj_catchall != NULL) {
   953     _igvn.replace_node(_memproj_catchall, C->top());
   954   }
   955   if (_ioproj_fallthrough != NULL) {
   956     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
   957   }
   958   if (_ioproj_catchall != NULL) {
   959     _igvn.replace_node(_ioproj_catchall, C->top());
   960   }
   961   if (_catchallcatchproj != NULL) {
   962     _igvn.replace_node(_catchallcatchproj, C->top());
   963   }
   964 }
   966 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
   967   // Don't do scalar replacement if the frame can be popped by JVMTI:
   968   // if reallocation fails during deoptimization we'll pop all
   969   // interpreter frames for this compiled frame and that won't play
   970   // nice with JVMTI popframe.
   971   if (!EliminateAllocations || JvmtiExport::can_pop_frame() || !alloc->_is_non_escaping) {
   972     return false;
   973   }
   974   Node* klass = alloc->in(AllocateNode::KlassNode);
   975   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
   976   Node* res = alloc->result_cast();
   977   // Eliminate boxing allocations which are not used
   978   // regardless scalar replacable status.
   979   bool boxing_alloc = C->eliminate_boxing() &&
   980                       tklass->klass()->is_instance_klass()  &&
   981                       tklass->klass()->as_instance_klass()->is_box_klass();
   982   if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
   983     return false;
   984   }
   986   extract_call_projections(alloc);
   988   GrowableArray <SafePointNode *> safepoints;
   989   if (!can_eliminate_allocation(alloc, safepoints)) {
   990     return false;
   991   }
   993   if (!alloc->_is_scalar_replaceable) {
   994     assert(res == NULL, "sanity");
   995     // We can only eliminate allocation if all debug info references
   996     // are already replaced with SafePointScalarObject because
   997     // we can't search for a fields value without instance_id.
   998     if (safepoints.length() > 0) {
   999       return false;
  1003   if (!scalar_replacement(alloc, safepoints)) {
  1004     return false;
  1007   CompileLog* log = C->log();
  1008   if (log != NULL) {
  1009     log->head("eliminate_allocation type='%d'",
  1010               log->identify(tklass->klass()));
  1011     JVMState* p = alloc->jvms();
  1012     while (p != NULL) {
  1013       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
  1014       p = p->caller();
  1016     log->tail("eliminate_allocation");
  1019   process_users_of_allocation(alloc);
  1021 #ifndef PRODUCT
  1022   if (PrintEliminateAllocations) {
  1023     if (alloc->is_AllocateArray())
  1024       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
  1025     else
  1026       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
  1028 #endif
  1030   return true;
  1033 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
  1034   // EA should remove all uses of non-escaping boxing node.
  1035   if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
  1036     return false;
  1039   assert(boxing->result_cast() == NULL, "unexpected boxing node result");
  1041   extract_call_projections(boxing);
  1043   const TypeTuple* r = boxing->tf()->range();
  1044   assert(r->cnt() > TypeFunc::Parms, "sanity");
  1045   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
  1046   assert(t != NULL, "sanity");
  1048   CompileLog* log = C->log();
  1049   if (log != NULL) {
  1050     log->head("eliminate_boxing type='%d'",
  1051               log->identify(t->klass()));
  1052     JVMState* p = boxing->jvms();
  1053     while (p != NULL) {
  1054       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
  1055       p = p->caller();
  1057     log->tail("eliminate_boxing");
  1060   process_users_of_allocation(boxing);
  1062 #ifndef PRODUCT
  1063   if (PrintEliminateAllocations) {
  1064     tty->print("++++ Eliminated: %d ", boxing->_idx);
  1065     boxing->method()->print_short_name(tty);
  1066     tty->cr();
  1068 #endif
  1070   return true;
  1073 //---------------------------set_eden_pointers-------------------------
  1074 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
  1075   if (UseTLAB) {                // Private allocation: load from TLS
  1076     Node* thread = transform_later(new (C) ThreadLocalNode());
  1077     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
  1078     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
  1079     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
  1080     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
  1081   } else {                      // Shared allocation: load from globals
  1082     CollectedHeap* ch = Universe::heap();
  1083     address top_adr = (address)ch->top_addr();
  1084     address end_adr = (address)ch->end_addr();
  1085     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
  1086     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
  1091 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
  1092   Node* adr = basic_plus_adr(base, offset);
  1093   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
  1094   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
  1095   transform_later(value);
  1096   return value;
  1100 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
  1101   Node* adr = basic_plus_adr(base, offset);
  1102   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
  1103   transform_later(mem);
  1104   return mem;
  1107 //=============================================================================
  1108 //
  1109 //                              A L L O C A T I O N
  1110 //
  1111 // Allocation attempts to be fast in the case of frequent small objects.
  1112 // It breaks down like this:
  1113 //
  1114 // 1) Size in doublewords is computed.  This is a constant for objects and
  1115 // variable for most arrays.  Doubleword units are used to avoid size
  1116 // overflow of huge doubleword arrays.  We need doublewords in the end for
  1117 // rounding.
  1118 //
  1119 // 2) Size is checked for being 'too large'.  Too-large allocations will go
  1120 // the slow path into the VM.  The slow path can throw any required
  1121 // exceptions, and does all the special checks for very large arrays.  The
  1122 // size test can constant-fold away for objects.  For objects with
  1123 // finalizers it constant-folds the otherway: you always go slow with
  1124 // finalizers.
  1125 //
  1126 // 3) If NOT using TLABs, this is the contended loop-back point.
  1127 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
  1128 //
  1129 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
  1130 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
  1131 // "size*8" we always enter the VM, where "largish" is a constant picked small
  1132 // enough that there's always space between the eden max and 4Gig (old space is
  1133 // there so it's quite large) and large enough that the cost of entering the VM
  1134 // is dwarfed by the cost to initialize the space.
  1135 //
  1136 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
  1137 // down.  If contended, repeat at step 3.  If using TLABs normal-store
  1138 // adjusted heap top back down; there is no contention.
  1139 //
  1140 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
  1141 // fields.
  1142 //
  1143 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
  1144 // oop flavor.
  1145 //
  1146 //=============================================================================
  1147 // FastAllocateSizeLimit value is in DOUBLEWORDS.
  1148 // Allocations bigger than this always go the slow route.
  1149 // This value must be small enough that allocation attempts that need to
  1150 // trigger exceptions go the slow route.  Also, it must be small enough so
  1151 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
  1152 //=============================================================================j//
  1153 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
  1154 // The allocator will coalesce int->oop copies away.  See comment in
  1155 // coalesce.cpp about how this works.  It depends critically on the exact
  1156 // code shape produced here, so if you are changing this code shape
  1157 // make sure the GC info for the heap-top is correct in and around the
  1158 // slow-path call.
  1159 //
  1161 void PhaseMacroExpand::expand_allocate_common(
  1162             AllocateNode* alloc, // allocation node to be expanded
  1163             Node* length,  // array length for an array allocation
  1164             const TypeFunc* slow_call_type, // Type of slow call
  1165             address slow_call_address  // Address of slow call
  1169   Node* ctrl = alloc->in(TypeFunc::Control);
  1170   Node* mem  = alloc->in(TypeFunc::Memory);
  1171   Node* i_o  = alloc->in(TypeFunc::I_O);
  1172   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
  1173   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
  1174   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
  1176   assert(ctrl != NULL, "must have control");
  1177   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
  1178   // they will not be used if "always_slow" is set
  1179   enum { slow_result_path = 1, fast_result_path = 2 };
  1180   Node *result_region;
  1181   Node *result_phi_rawmem;
  1182   Node *result_phi_rawoop;
  1183   Node *result_phi_i_o;
  1185   // The initial slow comparison is a size check, the comparison
  1186   // we want to do is a BoolTest::gt
  1187   bool always_slow = false;
  1188   int tv = _igvn.find_int_con(initial_slow_test, -1);
  1189   if (tv >= 0) {
  1190     always_slow = (tv == 1);
  1191     initial_slow_test = NULL;
  1192   } else {
  1193     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
  1196   if (C->env()->dtrace_alloc_probes() ||
  1197       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
  1198                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
  1199     // Force slow-path allocation
  1200     always_slow = true;
  1201     initial_slow_test = NULL;
  1205   enum { too_big_or_final_path = 1, need_gc_path = 2 };
  1206   Node *slow_region = NULL;
  1207   Node *toobig_false = ctrl;
  1209   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
  1210   // generate the initial test if necessary
  1211   if (initial_slow_test != NULL ) {
  1212     slow_region = new (C) RegionNode(3);
  1214     // Now make the initial failure test.  Usually a too-big test but
  1215     // might be a TRUE for finalizers or a fancy class check for
  1216     // newInstance0.
  1217     IfNode *toobig_iff = new (C) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
  1218     transform_later(toobig_iff);
  1219     // Plug the failing-too-big test into the slow-path region
  1220     Node *toobig_true = new (C) IfTrueNode( toobig_iff );
  1221     transform_later(toobig_true);
  1222     slow_region    ->init_req( too_big_or_final_path, toobig_true );
  1223     toobig_false = new (C) IfFalseNode( toobig_iff );
  1224     transform_later(toobig_false);
  1225   } else {         // No initial test, just fall into next case
  1226     toobig_false = ctrl;
  1227     debug_only(slow_region = NodeSentinel);
  1230   Node *slow_mem = mem;  // save the current memory state for slow path
  1231   // generate the fast allocation code unless we know that the initial test will always go slow
  1232   if (!always_slow) {
  1233     // Fast path modifies only raw memory.
  1234     if (mem->is_MergeMem()) {
  1235       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
  1238     Node* eden_top_adr;
  1239     Node* eden_end_adr;
  1241     set_eden_pointers(eden_top_adr, eden_end_adr);
  1243     // Load Eden::end.  Loop invariant and hoisted.
  1244     //
  1245     // Note: We set the control input on "eden_end" and "old_eden_top" when using
  1246     //       a TLAB to work around a bug where these values were being moved across
  1247     //       a safepoint.  These are not oops, so they cannot be include in the oop
  1248     //       map, but they can be changed by a GC.   The proper way to fix this would
  1249     //       be to set the raw memory state when generating a  SafepointNode.  However
  1250     //       this will require extensive changes to the loop optimization in order to
  1251     //       prevent a degradation of the optimization.
  1252     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
  1253     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
  1255     // allocate the Region and Phi nodes for the result
  1256     result_region = new (C) RegionNode(3);
  1257     result_phi_rawmem = new (C) PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1258     result_phi_rawoop = new (C) PhiNode(result_region, TypeRawPtr::BOTTOM);
  1259     result_phi_i_o    = new (C) PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
  1261     // We need a Region for the loop-back contended case.
  1262     enum { fall_in_path = 1, contended_loopback_path = 2 };
  1263     Node *contended_region;
  1264     Node *contended_phi_rawmem;
  1265     if (UseTLAB) {
  1266       contended_region = toobig_false;
  1267       contended_phi_rawmem = mem;
  1268     } else {
  1269       contended_region = new (C) RegionNode(3);
  1270       contended_phi_rawmem = new (C) PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1271       // Now handle the passing-too-big test.  We fall into the contended
  1272       // loop-back merge point.
  1273       contended_region    ->init_req(fall_in_path, toobig_false);
  1274       contended_phi_rawmem->init_req(fall_in_path, mem);
  1275       transform_later(contended_region);
  1276       transform_later(contended_phi_rawmem);
  1279     // Load(-locked) the heap top.
  1280     // See note above concerning the control input when using a TLAB
  1281     Node *old_eden_top = UseTLAB
  1282       ? new (C) LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered)
  1283       : new (C) LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr, MemNode::acquire);
  1285     transform_later(old_eden_top);
  1286     // Add to heap top to get a new heap top
  1287     Node *new_eden_top = new (C) AddPNode(top(), old_eden_top, size_in_bytes);
  1288     transform_later(new_eden_top);
  1289     // Check for needing a GC; compare against heap end
  1290     Node *needgc_cmp = new (C) CmpPNode(new_eden_top, eden_end);
  1291     transform_later(needgc_cmp);
  1292     Node *needgc_bol = new (C) BoolNode(needgc_cmp, BoolTest::ge);
  1293     transform_later(needgc_bol);
  1294     IfNode *needgc_iff = new (C) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
  1295     transform_later(needgc_iff);
  1297     // Plug the failing-heap-space-need-gc test into the slow-path region
  1298     Node *needgc_true = new (C) IfTrueNode(needgc_iff);
  1299     transform_later(needgc_true);
  1300     if (initial_slow_test) {
  1301       slow_region->init_req(need_gc_path, needgc_true);
  1302       // This completes all paths into the slow merge point
  1303       transform_later(slow_region);
  1304     } else {                      // No initial slow path needed!
  1305       // Just fall from the need-GC path straight into the VM call.
  1306       slow_region = needgc_true;
  1308     // No need for a GC.  Setup for the Store-Conditional
  1309     Node *needgc_false = new (C) IfFalseNode(needgc_iff);
  1310     transform_later(needgc_false);
  1312     // Grab regular I/O before optional prefetch may change it.
  1313     // Slow-path does no I/O so just set it to the original I/O.
  1314     result_phi_i_o->init_req(slow_result_path, i_o);
  1316     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
  1317                               old_eden_top, new_eden_top, length);
  1319     // Name successful fast-path variables
  1320     Node* fast_oop = old_eden_top;
  1321     Node* fast_oop_ctrl;
  1322     Node* fast_oop_rawmem;
  1324     // Store (-conditional) the modified eden top back down.
  1325     // StorePConditional produces flags for a test PLUS a modified raw
  1326     // memory state.
  1327     if (UseTLAB) {
  1328       Node* store_eden_top =
  1329         new (C) StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
  1330                               TypeRawPtr::BOTTOM, new_eden_top, MemNode::unordered);
  1331       transform_later(store_eden_top);
  1332       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
  1333       fast_oop_rawmem = store_eden_top;
  1334     } else {
  1335       Node* store_eden_top =
  1336         new (C) StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
  1337                                          new_eden_top, fast_oop/*old_eden_top*/);
  1338       transform_later(store_eden_top);
  1339       Node *contention_check = new (C) BoolNode(store_eden_top, BoolTest::ne);
  1340       transform_later(contention_check);
  1341       store_eden_top = new (C) SCMemProjNode(store_eden_top);
  1342       transform_later(store_eden_top);
  1344       // If not using TLABs, check to see if there was contention.
  1345       IfNode *contention_iff = new (C) IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
  1346       transform_later(contention_iff);
  1347       Node *contention_true = new (C) IfTrueNode(contention_iff);
  1348       transform_later(contention_true);
  1349       // If contention, loopback and try again.
  1350       contended_region->init_req(contended_loopback_path, contention_true);
  1351       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
  1353       // Fast-path succeeded with no contention!
  1354       Node *contention_false = new (C) IfFalseNode(contention_iff);
  1355       transform_later(contention_false);
  1356       fast_oop_ctrl = contention_false;
  1358       // Bump total allocated bytes for this thread
  1359       Node* thread = new (C) ThreadLocalNode();
  1360       transform_later(thread);
  1361       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
  1362                                              in_bytes(JavaThread::allocated_bytes_offset()));
  1363       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
  1364                                     0, TypeLong::LONG, T_LONG);
  1365 #ifdef _LP64
  1366       Node* alloc_size = size_in_bytes;
  1367 #else
  1368       Node* alloc_size = new (C) ConvI2LNode(size_in_bytes);
  1369       transform_later(alloc_size);
  1370 #endif
  1371       Node* new_alloc_bytes = new (C) AddLNode(alloc_bytes, alloc_size);
  1372       transform_later(new_alloc_bytes);
  1373       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
  1374                                    0, new_alloc_bytes, T_LONG);
  1377     InitializeNode* init = alloc->initialization();
  1378     fast_oop_rawmem = initialize_object(alloc,
  1379                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
  1380                                         klass_node, length, size_in_bytes);
  1382     // If initialization is performed by an array copy, any required
  1383     // MemBarStoreStore was already added. If the object does not
  1384     // escape no need for a MemBarStoreStore. Otherwise we need a
  1385     // MemBarStoreStore so that stores that initialize this object
  1386     // can't be reordered with a subsequent store that makes this
  1387     // object accessible by other threads.
  1388     if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
  1389       if (init == NULL || init->req() < InitializeNode::RawStores) {
  1390         // No InitializeNode or no stores captured by zeroing
  1391         // elimination. Simply add the MemBarStoreStore after object
  1392         // initialization.
  1393         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
  1394         transform_later(mb);
  1396         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
  1397         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
  1398         fast_oop_ctrl = new (C) ProjNode(mb,TypeFunc::Control);
  1399         transform_later(fast_oop_ctrl);
  1400         fast_oop_rawmem = new (C) ProjNode(mb,TypeFunc::Memory);
  1401         transform_later(fast_oop_rawmem);
  1402       } else {
  1403         // Add the MemBarStoreStore after the InitializeNode so that
  1404         // all stores performing the initialization that were moved
  1405         // before the InitializeNode happen before the storestore
  1406         // barrier.
  1408         Node* init_ctrl = init->proj_out(TypeFunc::Control);
  1409         Node* init_mem = init->proj_out(TypeFunc::Memory);
  1411         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
  1412         transform_later(mb);
  1414         Node* ctrl = new (C) ProjNode(init,TypeFunc::Control);
  1415         transform_later(ctrl);
  1416         Node* mem = new (C) ProjNode(init,TypeFunc::Memory);
  1417         transform_later(mem);
  1419         // The MemBarStoreStore depends on control and memory coming
  1420         // from the InitializeNode
  1421         mb->init_req(TypeFunc::Memory, mem);
  1422         mb->init_req(TypeFunc::Control, ctrl);
  1424         ctrl = new (C) ProjNode(mb,TypeFunc::Control);
  1425         transform_later(ctrl);
  1426         mem = new (C) ProjNode(mb,TypeFunc::Memory);
  1427         transform_later(mem);
  1429         // All nodes that depended on the InitializeNode for control
  1430         // and memory must now depend on the MemBarNode that itself
  1431         // depends on the InitializeNode
  1432         _igvn.replace_node(init_ctrl, ctrl);
  1433         _igvn.replace_node(init_mem, mem);
  1437     if (C->env()->dtrace_extended_probes()) {
  1438       // Slow-path call
  1439       int size = TypeFunc::Parms + 2;
  1440       CallLeafNode *call = new (C) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
  1441                                                 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
  1442                                                 "dtrace_object_alloc",
  1443                                                 TypeRawPtr::BOTTOM);
  1445       // Get base of thread-local storage area
  1446       Node* thread = new (C) ThreadLocalNode();
  1447       transform_later(thread);
  1449       call->init_req(TypeFunc::Parms+0, thread);
  1450       call->init_req(TypeFunc::Parms+1, fast_oop);
  1451       call->init_req(TypeFunc::Control, fast_oop_ctrl);
  1452       call->init_req(TypeFunc::I_O    , top()); // does no i/o
  1453       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
  1454       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
  1455       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
  1456       transform_later(call);
  1457       fast_oop_ctrl = new (C) ProjNode(call,TypeFunc::Control);
  1458       transform_later(fast_oop_ctrl);
  1459       fast_oop_rawmem = new (C) ProjNode(call,TypeFunc::Memory);
  1460       transform_later(fast_oop_rawmem);
  1463     // Plug in the successful fast-path into the result merge point
  1464     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
  1465     result_phi_rawoop->init_req(fast_result_path, fast_oop);
  1466     result_phi_i_o   ->init_req(fast_result_path, i_o);
  1467     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
  1468   } else {
  1469     slow_region = ctrl;
  1470     result_phi_i_o = i_o; // Rename it to use in the following code.
  1473   // Generate slow-path call
  1474   CallNode *call = new (C) CallStaticJavaNode(slow_call_type, slow_call_address,
  1475                                OptoRuntime::stub_name(slow_call_address),
  1476                                alloc->jvms()->bci(),
  1477                                TypePtr::BOTTOM);
  1478   call->init_req( TypeFunc::Control, slow_region );
  1479   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
  1480   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
  1481   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
  1482   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
  1484   call->init_req(TypeFunc::Parms+0, klass_node);
  1485   if (length != NULL) {
  1486     call->init_req(TypeFunc::Parms+1, length);
  1489   // Copy debug information and adjust JVMState information, then replace
  1490   // allocate node with the call
  1491   copy_call_debug_info((CallNode *) alloc,  call);
  1492   if (!always_slow) {
  1493     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
  1494   } else {
  1495     // Hook i_o projection to avoid its elimination during allocation
  1496     // replacement (when only a slow call is generated).
  1497     call->set_req(TypeFunc::I_O, result_phi_i_o);
  1499   _igvn.replace_node(alloc, call);
  1500   transform_later(call);
  1502   // Identify the output projections from the allocate node and
  1503   // adjust any references to them.
  1504   // The control and io projections look like:
  1505   //
  1506   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
  1507   //  Allocate                   Catch
  1508   //        ^---Proj(io) <-------+   ^---CatchProj(io)
  1509   //
  1510   //  We are interested in the CatchProj nodes.
  1511   //
  1512   extract_call_projections(call);
  1514   // An allocate node has separate memory projections for the uses on
  1515   // the control and i_o paths. Replace the control memory projection with
  1516   // result_phi_rawmem (unless we are only generating a slow call when
  1517   // both memory projections are combined)
  1518   if (!always_slow && _memproj_fallthrough != NULL) {
  1519     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1520       Node *use = _memproj_fallthrough->fast_out(i);
  1521       _igvn.rehash_node_delayed(use);
  1522       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
  1523       // back up iterator
  1524       --i;
  1527   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
  1528   // _memproj_catchall so we end up with a call that has only 1 memory projection.
  1529   if (_memproj_catchall != NULL ) {
  1530     if (_memproj_fallthrough == NULL) {
  1531       _memproj_fallthrough = new (C) ProjNode(call, TypeFunc::Memory);
  1532       transform_later(_memproj_fallthrough);
  1534     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
  1535       Node *use = _memproj_catchall->fast_out(i);
  1536       _igvn.rehash_node_delayed(use);
  1537       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
  1538       // back up iterator
  1539       --i;
  1541     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
  1542     _igvn.remove_dead_node(_memproj_catchall);
  1545   // An allocate node has separate i_o projections for the uses on the control
  1546   // and i_o paths. Always replace the control i_o projection with result i_o
  1547   // otherwise incoming i_o become dead when only a slow call is generated
  1548   // (it is different from memory projections where both projections are
  1549   // combined in such case).
  1550   if (_ioproj_fallthrough != NULL) {
  1551     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1552       Node *use = _ioproj_fallthrough->fast_out(i);
  1553       _igvn.rehash_node_delayed(use);
  1554       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
  1555       // back up iterator
  1556       --i;
  1559   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
  1560   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
  1561   if (_ioproj_catchall != NULL ) {
  1562     if (_ioproj_fallthrough == NULL) {
  1563       _ioproj_fallthrough = new (C) ProjNode(call, TypeFunc::I_O);
  1564       transform_later(_ioproj_fallthrough);
  1566     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
  1567       Node *use = _ioproj_catchall->fast_out(i);
  1568       _igvn.rehash_node_delayed(use);
  1569       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
  1570       // back up iterator
  1571       --i;
  1573     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
  1574     _igvn.remove_dead_node(_ioproj_catchall);
  1577   // if we generated only a slow call, we are done
  1578   if (always_slow) {
  1579     // Now we can unhook i_o.
  1580     if (result_phi_i_o->outcnt() > 1) {
  1581       call->set_req(TypeFunc::I_O, top());
  1582     } else {
  1583       assert(result_phi_i_o->unique_ctrl_out() == call, "");
  1584       // Case of new array with negative size known during compilation.
  1585       // AllocateArrayNode::Ideal() optimization disconnect unreachable
  1586       // following code since call to runtime will throw exception.
  1587       // As result there will be no users of i_o after the call.
  1588       // Leave i_o attached to this call to avoid problems in preceding graph.
  1590     return;
  1594   if (_fallthroughcatchproj != NULL) {
  1595     ctrl = _fallthroughcatchproj->clone();
  1596     transform_later(ctrl);
  1597     _igvn.replace_node(_fallthroughcatchproj, result_region);
  1598   } else {
  1599     ctrl = top();
  1601   Node *slow_result;
  1602   if (_resproj == NULL) {
  1603     // no uses of the allocation result
  1604     slow_result = top();
  1605   } else {
  1606     slow_result = _resproj->clone();
  1607     transform_later(slow_result);
  1608     _igvn.replace_node(_resproj, result_phi_rawoop);
  1611   // Plug slow-path into result merge point
  1612   result_region    ->init_req( slow_result_path, ctrl );
  1613   result_phi_rawoop->init_req( slow_result_path, slow_result);
  1614   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
  1615   transform_later(result_region);
  1616   transform_later(result_phi_rawoop);
  1617   transform_later(result_phi_rawmem);
  1618   transform_later(result_phi_i_o);
  1619   // This completes all paths into the result merge point
  1623 // Helper for PhaseMacroExpand::expand_allocate_common.
  1624 // Initializes the newly-allocated storage.
  1625 Node*
  1626 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
  1627                                     Node* control, Node* rawmem, Node* object,
  1628                                     Node* klass_node, Node* length,
  1629                                     Node* size_in_bytes) {
  1630   InitializeNode* init = alloc->initialization();
  1631   // Store the klass & mark bits
  1632   Node* mark_node = NULL;
  1633   // For now only enable fast locking for non-array types
  1634   if (UseBiasedLocking && (length == NULL)) {
  1635     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
  1636   } else {
  1637     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
  1639   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
  1641   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
  1642   int header_size = alloc->minimum_header_size();  // conservatively small
  1644   // Array length
  1645   if (length != NULL) {         // Arrays need length field
  1646     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
  1647     // conservatively small header size:
  1648     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1649     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1650     if (k->is_array_klass())    // we know the exact header size in most cases:
  1651       header_size = Klass::layout_helper_header_size(k->layout_helper());
  1654   // Clear the object body, if necessary.
  1655   if (init == NULL) {
  1656     // The init has somehow disappeared; be cautious and clear everything.
  1657     //
  1658     // This can happen if a node is allocated but an uncommon trap occurs
  1659     // immediately.  In this case, the Initialize gets associated with the
  1660     // trap, and may be placed in a different (outer) loop, if the Allocate
  1661     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
  1662     // there can be two Allocates to one Initialize.  The answer in all these
  1663     // edge cases is safety first.  It is always safe to clear immediately
  1664     // within an Allocate, and then (maybe or maybe not) clear some more later.
  1665     if (!ZeroTLAB)
  1666       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
  1667                                             header_size, size_in_bytes,
  1668                                             &_igvn);
  1669   } else {
  1670     if (!init->is_complete()) {
  1671       // Try to win by zeroing only what the init does not store.
  1672       // We can also try to do some peephole optimizations,
  1673       // such as combining some adjacent subword stores.
  1674       rawmem = init->complete_stores(control, rawmem, object,
  1675                                      header_size, size_in_bytes, &_igvn);
  1677     // We have no more use for this link, since the AllocateNode goes away:
  1678     init->set_req(InitializeNode::RawAddress, top());
  1679     // (If we keep the link, it just confuses the register allocator,
  1680     // who thinks he sees a real use of the address by the membar.)
  1683   return rawmem;
  1686 // Generate prefetch instructions for next allocations.
  1687 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
  1688                                         Node*& contended_phi_rawmem,
  1689                                         Node* old_eden_top, Node* new_eden_top,
  1690                                         Node* length) {
  1691    enum { fall_in_path = 1, pf_path = 2 };
  1692    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
  1693       // Generate prefetch allocation with watermark check.
  1694       // As an allocation hits the watermark, we will prefetch starting
  1695       // at a "distance" away from watermark.
  1697       Node *pf_region = new (C) RegionNode(3);
  1698       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
  1699                                                 TypeRawPtr::BOTTOM );
  1700       // I/O is used for Prefetch
  1701       Node *pf_phi_abio = new (C) PhiNode( pf_region, Type::ABIO );
  1703       Node *thread = new (C) ThreadLocalNode();
  1704       transform_later(thread);
  1706       Node *eden_pf_adr = new (C) AddPNode( top()/*not oop*/, thread,
  1707                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
  1708       transform_later(eden_pf_adr);
  1710       Node *old_pf_wm = new (C) LoadPNode(needgc_false,
  1711                                    contended_phi_rawmem, eden_pf_adr,
  1712                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
  1713                                    MemNode::unordered);
  1714       transform_later(old_pf_wm);
  1716       // check against new_eden_top
  1717       Node *need_pf_cmp = new (C) CmpPNode( new_eden_top, old_pf_wm );
  1718       transform_later(need_pf_cmp);
  1719       Node *need_pf_bol = new (C) BoolNode( need_pf_cmp, BoolTest::ge );
  1720       transform_later(need_pf_bol);
  1721       IfNode *need_pf_iff = new (C) IfNode( needgc_false, need_pf_bol,
  1722                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
  1723       transform_later(need_pf_iff);
  1725       // true node, add prefetchdistance
  1726       Node *need_pf_true = new (C) IfTrueNode( need_pf_iff );
  1727       transform_later(need_pf_true);
  1729       Node *need_pf_false = new (C) IfFalseNode( need_pf_iff );
  1730       transform_later(need_pf_false);
  1732       Node *new_pf_wmt = new (C) AddPNode( top(), old_pf_wm,
  1733                                     _igvn.MakeConX(AllocatePrefetchDistance) );
  1734       transform_later(new_pf_wmt );
  1735       new_pf_wmt->set_req(0, need_pf_true);
  1737       Node *store_new_wmt = new (C) StorePNode(need_pf_true,
  1738                                        contended_phi_rawmem, eden_pf_adr,
  1739                                        TypeRawPtr::BOTTOM, new_pf_wmt,
  1740                                        MemNode::unordered);
  1741       transform_later(store_new_wmt);
  1743       // adding prefetches
  1744       pf_phi_abio->init_req( fall_in_path, i_o );
  1746       Node *prefetch_adr;
  1747       Node *prefetch;
  1748       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
  1749       uint step_size = AllocatePrefetchStepSize;
  1750       uint distance = 0;
  1752       for ( uint i = 0; i < lines; i++ ) {
  1753         prefetch_adr = new (C) AddPNode( old_pf_wm, new_pf_wmt,
  1754                                             _igvn.MakeConX(distance) );
  1755         transform_later(prefetch_adr);
  1756         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
  1757         transform_later(prefetch);
  1758         distance += step_size;
  1759         i_o = prefetch;
  1761       pf_phi_abio->set_req( pf_path, i_o );
  1763       pf_region->init_req( fall_in_path, need_pf_false );
  1764       pf_region->init_req( pf_path, need_pf_true );
  1766       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
  1767       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
  1769       transform_later(pf_region);
  1770       transform_later(pf_phi_rawmem);
  1771       transform_later(pf_phi_abio);
  1773       needgc_false = pf_region;
  1774       contended_phi_rawmem = pf_phi_rawmem;
  1775       i_o = pf_phi_abio;
  1776    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
  1777       // Insert a prefetch for each allocation.
  1778       // This code is used for Sparc with BIS.
  1779       Node *pf_region = new (C) RegionNode(3);
  1780       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
  1781                                              TypeRawPtr::BOTTOM );
  1783       // Generate several prefetch instructions.
  1784       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
  1785       uint step_size = AllocatePrefetchStepSize;
  1786       uint distance = AllocatePrefetchDistance;
  1788       // Next cache address.
  1789       Node *cache_adr = new (C) AddPNode(old_eden_top, old_eden_top,
  1790                                             _igvn.MakeConX(distance));
  1791       transform_later(cache_adr);
  1792       cache_adr = new (C) CastP2XNode(needgc_false, cache_adr);
  1793       transform_later(cache_adr);
  1794       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
  1795       cache_adr = new (C) AndXNode(cache_adr, mask);
  1796       transform_later(cache_adr);
  1797       cache_adr = new (C) CastX2PNode(cache_adr);
  1798       transform_later(cache_adr);
  1800       // Prefetch
  1801       Node *prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
  1802       prefetch->set_req(0, needgc_false);
  1803       transform_later(prefetch);
  1804       contended_phi_rawmem = prefetch;
  1805       Node *prefetch_adr;
  1806       distance = step_size;
  1807       for ( uint i = 1; i < lines; i++ ) {
  1808         prefetch_adr = new (C) AddPNode( cache_adr, cache_adr,
  1809                                             _igvn.MakeConX(distance) );
  1810         transform_later(prefetch_adr);
  1811         prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
  1812         transform_later(prefetch);
  1813         distance += step_size;
  1814         contended_phi_rawmem = prefetch;
  1816    } else if( AllocatePrefetchStyle > 0 ) {
  1817       // Insert a prefetch for each allocation only on the fast-path
  1818       Node *prefetch_adr;
  1819       Node *prefetch;
  1820       // Generate several prefetch instructions.
  1821       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
  1822       uint step_size = AllocatePrefetchStepSize;
  1823       uint distance = AllocatePrefetchDistance;
  1824       for ( uint i = 0; i < lines; i++ ) {
  1825         prefetch_adr = new (C) AddPNode( old_eden_top, new_eden_top,
  1826                                             _igvn.MakeConX(distance) );
  1827         transform_later(prefetch_adr);
  1828         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
  1829         // Do not let it float too high, since if eden_top == eden_end,
  1830         // both might be null.
  1831         if( i == 0 ) { // Set control for first prefetch, next follows it
  1832           prefetch->init_req(0, needgc_false);
  1834         transform_later(prefetch);
  1835         distance += step_size;
  1836         i_o = prefetch;
  1839    return i_o;
  1843 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
  1844   expand_allocate_common(alloc, NULL,
  1845                          OptoRuntime::new_instance_Type(),
  1846                          OptoRuntime::new_instance_Java());
  1849 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
  1850   Node* length = alloc->in(AllocateNode::ALength);
  1851   InitializeNode* init = alloc->initialization();
  1852   Node* klass_node = alloc->in(AllocateNode::KlassNode);
  1853   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1854   address slow_call_address;  // Address of slow call
  1855   if (init != NULL && init->is_complete_with_arraycopy() &&
  1856       k->is_type_array_klass()) {
  1857     // Don't zero type array during slow allocation in VM since
  1858     // it will be initialized later by arraycopy in compiled code.
  1859     slow_call_address = OptoRuntime::new_array_nozero_Java();
  1860   } else {
  1861     slow_call_address = OptoRuntime::new_array_Java();
  1863   expand_allocate_common(alloc, length,
  1864                          OptoRuntime::new_array_Type(),
  1865                          slow_call_address);
  1868 //-------------------mark_eliminated_box----------------------------------
  1869 //
  1870 // During EA obj may point to several objects but after few ideal graph
  1871 // transformations (CCP) it may point to only one non escaping object
  1872 // (but still using phi), corresponding locks and unlocks will be marked
  1873 // for elimination. Later obj could be replaced with a new node (new phi)
  1874 // and which does not have escape information. And later after some graph
  1875 // reshape other locks and unlocks (which were not marked for elimination
  1876 // before) are connected to this new obj (phi) but they still will not be
  1877 // marked for elimination since new obj has no escape information.
  1878 // Mark all associated (same box and obj) lock and unlock nodes for
  1879 // elimination if some of them marked already.
  1880 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
  1881   if (oldbox->as_BoxLock()->is_eliminated())
  1882     return; // This BoxLock node was processed already.
  1884   // New implementation (EliminateNestedLocks) has separate BoxLock
  1885   // node for each locked region so mark all associated locks/unlocks as
  1886   // eliminated even if different objects are referenced in one locked region
  1887   // (for example, OSR compilation of nested loop inside locked scope).
  1888   if (EliminateNestedLocks ||
  1889       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
  1890     // Box is used only in one lock region. Mark this box as eliminated.
  1891     _igvn.hash_delete(oldbox);
  1892     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
  1893     _igvn.hash_insert(oldbox);
  1895     for (uint i = 0; i < oldbox->outcnt(); i++) {
  1896       Node* u = oldbox->raw_out(i);
  1897       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
  1898         AbstractLockNode* alock = u->as_AbstractLock();
  1899         // Check lock's box since box could be referenced by Lock's debug info.
  1900         if (alock->box_node() == oldbox) {
  1901           // Mark eliminated all related locks and unlocks.
  1902           alock->set_non_esc_obj();
  1906     return;
  1909   // Create new "eliminated" BoxLock node and use it in monitor debug info
  1910   // instead of oldbox for the same object.
  1911   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
  1913   // Note: BoxLock node is marked eliminated only here and it is used
  1914   // to indicate that all associated lock and unlock nodes are marked
  1915   // for elimination.
  1916   newbox->set_eliminated();
  1917   transform_later(newbox);
  1919   // Replace old box node with new box for all users of the same object.
  1920   for (uint i = 0; i < oldbox->outcnt();) {
  1921     bool next_edge = true;
  1923     Node* u = oldbox->raw_out(i);
  1924     if (u->is_AbstractLock()) {
  1925       AbstractLockNode* alock = u->as_AbstractLock();
  1926       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
  1927         // Replace Box and mark eliminated all related locks and unlocks.
  1928         alock->set_non_esc_obj();
  1929         _igvn.rehash_node_delayed(alock);
  1930         alock->set_box_node(newbox);
  1931         next_edge = false;
  1934     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
  1935       FastLockNode* flock = u->as_FastLock();
  1936       assert(flock->box_node() == oldbox, "sanity");
  1937       _igvn.rehash_node_delayed(flock);
  1938       flock->set_box_node(newbox);
  1939       next_edge = false;
  1942     // Replace old box in monitor debug info.
  1943     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
  1944       SafePointNode* sfn = u->as_SafePoint();
  1945       JVMState* youngest_jvms = sfn->jvms();
  1946       int max_depth = youngest_jvms->depth();
  1947       for (int depth = 1; depth <= max_depth; depth++) {
  1948         JVMState* jvms = youngest_jvms->of_depth(depth);
  1949         int num_mon  = jvms->nof_monitors();
  1950         // Loop over monitors
  1951         for (int idx = 0; idx < num_mon; idx++) {
  1952           Node* obj_node = sfn->monitor_obj(jvms, idx);
  1953           Node* box_node = sfn->monitor_box(jvms, idx);
  1954           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
  1955             int j = jvms->monitor_box_offset(idx);
  1956             _igvn.replace_input_of(u, j, newbox);
  1957             next_edge = false;
  1962     if (next_edge) i++;
  1966 //-----------------------mark_eliminated_locking_nodes-----------------------
  1967 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
  1968   if (EliminateNestedLocks) {
  1969     if (alock->is_nested()) {
  1970        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
  1971        return;
  1972     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
  1973       // Only Lock node has JVMState needed here.
  1974       if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
  1975         // Mark eliminated related nested locks and unlocks.
  1976         Node* obj = alock->obj_node();
  1977         BoxLockNode* box_node = alock->box_node()->as_BoxLock();
  1978         assert(!box_node->is_eliminated(), "should not be marked yet");
  1979         // Note: BoxLock node is marked eliminated only here
  1980         // and it is used to indicate that all associated lock
  1981         // and unlock nodes are marked for elimination.
  1982         box_node->set_eliminated(); // Box's hash is always NO_HASH here
  1983         for (uint i = 0; i < box_node->outcnt(); i++) {
  1984           Node* u = box_node->raw_out(i);
  1985           if (u->is_AbstractLock()) {
  1986             alock = u->as_AbstractLock();
  1987             if (alock->box_node() == box_node) {
  1988               // Verify that this Box is referenced only by related locks.
  1989               assert(alock->obj_node()->eqv_uncast(obj), "");
  1990               // Mark all related locks and unlocks.
  1991               alock->set_nested();
  1996       return;
  1998     // Process locks for non escaping object
  1999     assert(alock->is_non_esc_obj(), "");
  2000   } // EliminateNestedLocks
  2002   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
  2003     // Look for all locks of this object and mark them and
  2004     // corresponding BoxLock nodes as eliminated.
  2005     Node* obj = alock->obj_node();
  2006     for (uint j = 0; j < obj->outcnt(); j++) {
  2007       Node* o = obj->raw_out(j);
  2008       if (o->is_AbstractLock() &&
  2009           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
  2010         alock = o->as_AbstractLock();
  2011         Node* box = alock->box_node();
  2012         // Replace old box node with new eliminated box for all users
  2013         // of the same object and mark related locks as eliminated.
  2014         mark_eliminated_box(box, obj);
  2020 // we have determined that this lock/unlock can be eliminated, we simply
  2021 // eliminate the node without expanding it.
  2022 //
  2023 // Note:  The membar's associated with the lock/unlock are currently not
  2024 //        eliminated.  This should be investigated as a future enhancement.
  2025 //
  2026 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
  2028   if (!alock->is_eliminated()) {
  2029     return false;
  2031 #ifdef ASSERT
  2032   if (!alock->is_coarsened()) {
  2033     // Check that new "eliminated" BoxLock node is created.
  2034     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
  2035     assert(oldbox->is_eliminated(), "should be done already");
  2037 #endif
  2038   CompileLog* log = C->log();
  2039   if (log != NULL) {
  2040     log->head("eliminate_lock lock='%d'",
  2041               alock->is_Lock());
  2042     JVMState* p = alock->jvms();
  2043     while (p != NULL) {
  2044       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
  2045       p = p->caller();
  2047     log->tail("eliminate_lock");
  2050   #ifndef PRODUCT
  2051   if (PrintEliminateLocks) {
  2052     if (alock->is_Lock()) {
  2053       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
  2054     } else {
  2055       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
  2058   #endif
  2060   Node* mem  = alock->in(TypeFunc::Memory);
  2061   Node* ctrl = alock->in(TypeFunc::Control);
  2063   extract_call_projections(alock);
  2064   // There are 2 projections from the lock.  The lock node will
  2065   // be deleted when its last use is subsumed below.
  2066   assert(alock->outcnt() == 2 &&
  2067          _fallthroughproj != NULL &&
  2068          _memproj_fallthrough != NULL,
  2069          "Unexpected projections from Lock/Unlock");
  2071   Node* fallthroughproj = _fallthroughproj;
  2072   Node* memproj_fallthrough = _memproj_fallthrough;
  2074   // The memory projection from a lock/unlock is RawMem
  2075   // The input to a Lock is merged memory, so extract its RawMem input
  2076   // (unless the MergeMem has been optimized away.)
  2077   if (alock->is_Lock()) {
  2078     // Seach for MemBarAcquireLock node and delete it also.
  2079     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
  2080     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
  2081     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
  2082     Node* memproj = membar->proj_out(TypeFunc::Memory);
  2083     _igvn.replace_node(ctrlproj, fallthroughproj);
  2084     _igvn.replace_node(memproj, memproj_fallthrough);
  2086     // Delete FastLock node also if this Lock node is unique user
  2087     // (a loop peeling may clone a Lock node).
  2088     Node* flock = alock->as_Lock()->fastlock_node();
  2089     if (flock->outcnt() == 1) {
  2090       assert(flock->unique_out() == alock, "sanity");
  2091       _igvn.replace_node(flock, top());
  2095   // Seach for MemBarReleaseLock node and delete it also.
  2096   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
  2097       ctrl->in(0)->is_MemBar()) {
  2098     MemBarNode* membar = ctrl->in(0)->as_MemBar();
  2099     assert(membar->Opcode() == Op_MemBarReleaseLock &&
  2100            mem->is_Proj() && membar == mem->in(0), "");
  2101     _igvn.replace_node(fallthroughproj, ctrl);
  2102     _igvn.replace_node(memproj_fallthrough, mem);
  2103     fallthroughproj = ctrl;
  2104     memproj_fallthrough = mem;
  2105     ctrl = membar->in(TypeFunc::Control);
  2106     mem  = membar->in(TypeFunc::Memory);
  2109   _igvn.replace_node(fallthroughproj, ctrl);
  2110   _igvn.replace_node(memproj_fallthrough, mem);
  2111   return true;
  2115 //------------------------------expand_lock_node----------------------
  2116 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
  2118   Node* ctrl = lock->in(TypeFunc::Control);
  2119   Node* mem = lock->in(TypeFunc::Memory);
  2120   Node* obj = lock->obj_node();
  2121   Node* box = lock->box_node();
  2122   Node* flock = lock->fastlock_node();
  2124   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
  2126   // Make the merge point
  2127   Node *region;
  2128   Node *mem_phi;
  2129   Node *slow_path;
  2131   if (UseOptoBiasInlining) {
  2132     /*
  2133      *  See the full description in MacroAssembler::biased_locking_enter().
  2135      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
  2136      *    // The object is biased.
  2137      *    proto_node = klass->prototype_header;
  2138      *    o_node = thread | proto_node;
  2139      *    x_node = o_node ^ mark_word;
  2140      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
  2141      *      // Done.
  2142      *    } else {
  2143      *      if( (x_node & biased_lock_mask) != 0 ) {
  2144      *        // The klass's prototype header is no longer biased.
  2145      *        cas(&mark_word, mark_word, proto_node)
  2146      *        goto cas_lock;
  2147      *      } else {
  2148      *        // The klass's prototype header is still biased.
  2149      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
  2150      *          old = mark_word;
  2151      *          new = o_node;
  2152      *        } else {
  2153      *          // Different thread or anonymous biased.
  2154      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
  2155      *          new = thread | old;
  2156      *        }
  2157      *        // Try to rebias.
  2158      *        if( cas(&mark_word, old, new) == 0 ) {
  2159      *          // Done.
  2160      *        } else {
  2161      *          goto slow_path; // Failed.
  2162      *        }
  2163      *      }
  2164      *    }
  2165      *  } else {
  2166      *    // The object is not biased.
  2167      *    cas_lock:
  2168      *    if( FastLock(obj) == 0 ) {
  2169      *      // Done.
  2170      *    } else {
  2171      *      slow_path:
  2172      *      OptoRuntime::complete_monitor_locking_Java(obj);
  2173      *    }
  2174      *  }
  2175      */
  2177     region  = new (C) RegionNode(5);
  2178     // create a Phi for the memory state
  2179     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2181     Node* fast_lock_region  = new (C) RegionNode(3);
  2182     Node* fast_lock_mem_phi = new (C) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2184     // First, check mark word for the biased lock pattern.
  2185     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  2187     // Get fast path - mark word has the biased lock pattern.
  2188     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
  2189                          markOopDesc::biased_lock_mask_in_place,
  2190                          markOopDesc::biased_lock_pattern, true);
  2191     // fast_lock_region->in(1) is set to slow path.
  2192     fast_lock_mem_phi->init_req(1, mem);
  2194     // Now check that the lock is biased to the current thread and has
  2195     // the same epoch and bias as Klass::_prototype_header.
  2197     // Special-case a fresh allocation to avoid building nodes:
  2198     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
  2199     if (klass_node == NULL) {
  2200       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
  2201       klass_node = transform_later(LoadKlassNode::make(_igvn, NULL, mem, k_adr, _igvn.type(k_adr)->is_ptr()));
  2202 #ifdef _LP64
  2203       if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
  2204         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
  2205         klass_node->in(1)->init_req(0, ctrl);
  2206       } else
  2207 #endif
  2208       klass_node->init_req(0, ctrl);
  2210     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
  2212     Node* thread = transform_later(new (C) ThreadLocalNode());
  2213     Node* cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
  2214     Node* o_node = transform_later(new (C) OrXNode(cast_thread, proto_node));
  2215     Node* x_node = transform_later(new (C) XorXNode(o_node, mark_node));
  2217     // Get slow path - mark word does NOT match the value.
  2218     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
  2219                                       (~markOopDesc::age_mask_in_place), 0);
  2220     // region->in(3) is set to fast path - the object is biased to the current thread.
  2221     mem_phi->init_req(3, mem);
  2224     // Mark word does NOT match the value (thread | Klass::_prototype_header).
  2227     // First, check biased pattern.
  2228     // Get fast path - _prototype_header has the same biased lock pattern.
  2229     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
  2230                           markOopDesc::biased_lock_mask_in_place, 0, true);
  2232     not_biased_ctrl = fast_lock_region->in(2); // Slow path
  2233     // fast_lock_region->in(2) - the prototype header is no longer biased
  2234     // and we have to revoke the bias on this object.
  2235     // We are going to try to reset the mark of this object to the prototype
  2236     // value and fall through to the CAS-based locking scheme.
  2237     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
  2238     Node* cas = new (C) StoreXConditionalNode(not_biased_ctrl, mem, adr,
  2239                                               proto_node, mark_node);
  2240     transform_later(cas);
  2241     Node* proj = transform_later( new (C) SCMemProjNode(cas));
  2242     fast_lock_mem_phi->init_req(2, proj);
  2245     // Second, check epoch bits.
  2246     Node* rebiased_region  = new (C) RegionNode(3);
  2247     Node* old_phi = new (C) PhiNode( rebiased_region, TypeX_X);
  2248     Node* new_phi = new (C) PhiNode( rebiased_region, TypeX_X);
  2250     // Get slow path - mark word does NOT match epoch bits.
  2251     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
  2252                                       markOopDesc::epoch_mask_in_place, 0);
  2253     // The epoch of the current bias is not valid, attempt to rebias the object
  2254     // toward the current thread.
  2255     rebiased_region->init_req(2, epoch_ctrl);
  2256     old_phi->init_req(2, mark_node);
  2257     new_phi->init_req(2, o_node);
  2259     // rebiased_region->in(1) is set to fast path.
  2260     // The epoch of the current bias is still valid but we know
  2261     // nothing about the owner; it might be set or it might be clear.
  2262     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
  2263                              markOopDesc::age_mask_in_place |
  2264                              markOopDesc::epoch_mask_in_place);
  2265     Node* old = transform_later(new (C) AndXNode(mark_node, cmask));
  2266     cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
  2267     Node* new_mark = transform_later(new (C) OrXNode(cast_thread, old));
  2268     old_phi->init_req(1, old);
  2269     new_phi->init_req(1, new_mark);
  2271     transform_later(rebiased_region);
  2272     transform_later(old_phi);
  2273     transform_later(new_phi);
  2275     // Try to acquire the bias of the object using an atomic operation.
  2276     // If this fails we will go in to the runtime to revoke the object's bias.
  2277     cas = new (C) StoreXConditionalNode(rebiased_region, mem, adr,
  2278                                            new_phi, old_phi);
  2279     transform_later(cas);
  2280     proj = transform_later( new (C) SCMemProjNode(cas));
  2282     // Get slow path - Failed to CAS.
  2283     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
  2284     mem_phi->init_req(4, proj);
  2285     // region->in(4) is set to fast path - the object is rebiased to the current thread.
  2287     // Failed to CAS.
  2288     slow_path  = new (C) RegionNode(3);
  2289     Node *slow_mem = new (C) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
  2291     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
  2292     slow_mem->init_req(1, proj);
  2294     // Call CAS-based locking scheme (FastLock node).
  2296     transform_later(fast_lock_region);
  2297     transform_later(fast_lock_mem_phi);
  2299     // Get slow path - FastLock failed to lock the object.
  2300     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
  2301     mem_phi->init_req(2, fast_lock_mem_phi);
  2302     // region->in(2) is set to fast path - the object is locked to the current thread.
  2304     slow_path->init_req(2, ctrl); // Capture slow-control
  2305     slow_mem->init_req(2, fast_lock_mem_phi);
  2307     transform_later(slow_path);
  2308     transform_later(slow_mem);
  2309     // Reset lock's memory edge.
  2310     lock->set_req(TypeFunc::Memory, slow_mem);
  2312   } else {
  2313     region  = new (C) RegionNode(3);
  2314     // create a Phi for the memory state
  2315     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2317     // Optimize test; set region slot 2
  2318     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
  2319     mem_phi->init_req(2, mem);
  2322   // Make slow path call
  2323   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
  2325   extract_call_projections(call);
  2327   // Slow path can only throw asynchronous exceptions, which are always
  2328   // de-opted.  So the compiler thinks the slow-call can never throw an
  2329   // exception.  If it DOES throw an exception we would need the debug
  2330   // info removed first (since if it throws there is no monitor).
  2331   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  2332            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  2334   // Capture slow path
  2335   // disconnect fall-through projection from call and create a new one
  2336   // hook up users of fall-through projection to region
  2337   Node *slow_ctrl = _fallthroughproj->clone();
  2338   transform_later(slow_ctrl);
  2339   _igvn.hash_delete(_fallthroughproj);
  2340   _fallthroughproj->disconnect_inputs(NULL, C);
  2341   region->init_req(1, slow_ctrl);
  2342   // region inputs are now complete
  2343   transform_later(region);
  2344   _igvn.replace_node(_fallthroughproj, region);
  2346   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
  2347   mem_phi->init_req(1, memproj );
  2348   transform_later(mem_phi);
  2349   _igvn.replace_node(_memproj_fallthrough, mem_phi);
  2352 //------------------------------expand_unlock_node----------------------
  2353 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
  2355   Node* ctrl = unlock->in(TypeFunc::Control);
  2356   Node* mem = unlock->in(TypeFunc::Memory);
  2357   Node* obj = unlock->obj_node();
  2358   Node* box = unlock->box_node();
  2360   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
  2362   // No need for a null check on unlock
  2364   // Make the merge point
  2365   Node *region;
  2366   Node *mem_phi;
  2368   if (UseOptoBiasInlining) {
  2369     // Check for biased locking unlock case, which is a no-op.
  2370     // See the full description in MacroAssembler::biased_locking_exit().
  2371     region  = new (C) RegionNode(4);
  2372     // create a Phi for the memory state
  2373     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2374     mem_phi->init_req(3, mem);
  2376     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  2377     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
  2378                          markOopDesc::biased_lock_mask_in_place,
  2379                          markOopDesc::biased_lock_pattern);
  2380   } else {
  2381     region  = new (C) RegionNode(3);
  2382     // create a Phi for the memory state
  2383     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2386   FastUnlockNode *funlock = new (C) FastUnlockNode( ctrl, obj, box );
  2387   funlock = transform_later( funlock )->as_FastUnlock();
  2388   // Optimize test; set region slot 2
  2389   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
  2391   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 );
  2393   extract_call_projections(call);
  2395   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  2396            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  2398   // No exceptions for unlocking
  2399   // Capture slow path
  2400   // disconnect fall-through projection from call and create a new one
  2401   // hook up users of fall-through projection to region
  2402   Node *slow_ctrl = _fallthroughproj->clone();
  2403   transform_later(slow_ctrl);
  2404   _igvn.hash_delete(_fallthroughproj);
  2405   _fallthroughproj->disconnect_inputs(NULL, C);
  2406   region->init_req(1, slow_ctrl);
  2407   // region inputs are now complete
  2408   transform_later(region);
  2409   _igvn.replace_node(_fallthroughproj, region);
  2411   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
  2412   mem_phi->init_req(1, memproj );
  2413   mem_phi->init_req(2, mem);
  2414   transform_later(mem_phi);
  2415   _igvn.replace_node(_memproj_fallthrough, mem_phi);
  2418 //---------------------------eliminate_macro_nodes----------------------
  2419 // Eliminate scalar replaced allocations and associated locks.
  2420 void PhaseMacroExpand::eliminate_macro_nodes() {
  2421   if (C->macro_count() == 0)
  2422     return;
  2424   // First, attempt to eliminate locks
  2425   int cnt = C->macro_count();
  2426   for (int i=0; i < cnt; i++) {
  2427     Node *n = C->macro_node(i);
  2428     if (n->is_AbstractLock()) { // Lock and Unlock nodes
  2429       // Before elimination mark all associated (same box and obj)
  2430       // lock and unlock nodes.
  2431       mark_eliminated_locking_nodes(n->as_AbstractLock());
  2434   bool progress = true;
  2435   while (progress) {
  2436     progress = false;
  2437     for (int i = C->macro_count(); i > 0; i--) {
  2438       Node * n = C->macro_node(i-1);
  2439       bool success = false;
  2440       debug_only(int old_macro_count = C->macro_count(););
  2441       if (n->is_AbstractLock()) {
  2442         success = eliminate_locking_node(n->as_AbstractLock());
  2444       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2445       progress = progress || success;
  2448   // Next, attempt to eliminate allocations
  2449   _has_locks = false;
  2450   progress = true;
  2451   while (progress) {
  2452     progress = false;
  2453     for (int i = C->macro_count(); i > 0; i--) {
  2454       Node * n = C->macro_node(i-1);
  2455       bool success = false;
  2456       debug_only(int old_macro_count = C->macro_count(););
  2457       switch (n->class_id()) {
  2458       case Node::Class_Allocate:
  2459       case Node::Class_AllocateArray:
  2460         success = eliminate_allocate_node(n->as_Allocate());
  2461         break;
  2462       case Node::Class_CallStaticJava:
  2463         success = eliminate_boxing_node(n->as_CallStaticJava());
  2464         break;
  2465       case Node::Class_Lock:
  2466       case Node::Class_Unlock:
  2467         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
  2468         _has_locks = true;
  2469         break;
  2470       default:
  2471         assert(n->Opcode() == Op_LoopLimit ||
  2472                n->Opcode() == Op_Opaque1   ||
  2473                n->Opcode() == Op_Opaque2   ||
  2474                n->Opcode() == Op_Opaque3, "unknown node type in macro list");
  2476       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2477       progress = progress || success;
  2482 //------------------------------expand_macro_nodes----------------------
  2483 //  Returns true if a failure occurred.
  2484 bool PhaseMacroExpand::expand_macro_nodes() {
  2485   // Last attempt to eliminate macro nodes.
  2486   eliminate_macro_nodes();
  2488   // Make sure expansion will not cause node limit to be exceeded.
  2489   // Worst case is a macro node gets expanded into about 50 nodes.
  2490   // Allow 50% more for optimization.
  2491   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
  2492     return true;
  2494   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
  2495   bool progress = true;
  2496   while (progress) {
  2497     progress = false;
  2498     for (int i = C->macro_count(); i > 0; i--) {
  2499       Node * n = C->macro_node(i-1);
  2500       bool success = false;
  2501       debug_only(int old_macro_count = C->macro_count(););
  2502       if (n->Opcode() == Op_LoopLimit) {
  2503         // Remove it from macro list and put on IGVN worklist to optimize.
  2504         C->remove_macro_node(n);
  2505         _igvn._worklist.push(n);
  2506         success = true;
  2507       } else if (n->Opcode() == Op_CallStaticJava) {
  2508         // Remove it from macro list and put on IGVN worklist to optimize.
  2509         C->remove_macro_node(n);
  2510         _igvn._worklist.push(n);
  2511         success = true;
  2512       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
  2513         _igvn.replace_node(n, n->in(1));
  2514         success = true;
  2515 #if INCLUDE_RTM_OPT
  2516       } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
  2517         assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
  2518         assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
  2519         Node* cmp = n->unique_out();
  2520 #ifdef ASSERT
  2521         // Validate graph.
  2522         assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
  2523         BoolNode* bol = cmp->unique_out()->as_Bool();
  2524         assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
  2525                (bol->_test._test == BoolTest::ne), "");
  2526         IfNode* ifn = bol->unique_out()->as_If();
  2527         assert((ifn->outcnt() == 2) &&
  2528                ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change), "");
  2529 #endif
  2530         Node* repl = n->in(1);
  2531         if (!_has_locks) {
  2532           // Remove RTM state check if there are no locks in the code.
  2533           // Replace input to compare the same value.
  2534           repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
  2536         _igvn.replace_node(n, repl);
  2537         success = true;
  2538 #endif
  2540       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2541       progress = progress || success;
  2545   // expand "macro" nodes
  2546   // nodes are removed from the macro list as they are processed
  2547   while (C->macro_count() > 0) {
  2548     int macro_count = C->macro_count();
  2549     Node * n = C->macro_node(macro_count-1);
  2550     assert(n->is_macro(), "only macro nodes expected here");
  2551     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
  2552       // node is unreachable, so don't try to expand it
  2553       C->remove_macro_node(n);
  2554       continue;
  2556     switch (n->class_id()) {
  2557     case Node::Class_Allocate:
  2558       expand_allocate(n->as_Allocate());
  2559       break;
  2560     case Node::Class_AllocateArray:
  2561       expand_allocate_array(n->as_AllocateArray());
  2562       break;
  2563     case Node::Class_Lock:
  2564       expand_lock_node(n->as_Lock());
  2565       break;
  2566     case Node::Class_Unlock:
  2567       expand_unlock_node(n->as_Unlock());
  2568       break;
  2569     default:
  2570       assert(false, "unknown node type in macro list");
  2572     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
  2573     if (C->failing())  return true;
  2576   _igvn.set_delay_transform(false);
  2577   _igvn.optimize();
  2578   if (C->failing())  return true;
  2579   return false;

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