src/share/vm/opto/macro.cpp

Mon, 12 Aug 2013 17:37:02 +0200

author
ehelin
date
Mon, 12 Aug 2013 17:37:02 +0200
changeset 5694
7944aba7ba41
parent 5626
766fac3395d6
child 6198
55fb97c4c58d
child 6479
2113136690bc
permissions
-rw-r--r--

8015107: NPG: Use consistent naming for metaspace concepts
Reviewed-by: coleenp, mgerdin, hseigel

     1 /*
     2  * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "compiler/compileLog.hpp"
    27 #include "libadt/vectset.hpp"
    28 #include "opto/addnode.hpp"
    29 #include "opto/callnode.hpp"
    30 #include "opto/cfgnode.hpp"
    31 #include "opto/compile.hpp"
    32 #include "opto/connode.hpp"
    33 #include "opto/locknode.hpp"
    34 #include "opto/loopnode.hpp"
    35 #include "opto/macro.hpp"
    36 #include "opto/memnode.hpp"
    37 #include "opto/node.hpp"
    38 #include "opto/phaseX.hpp"
    39 #include "opto/rootnode.hpp"
    40 #include "opto/runtime.hpp"
    41 #include "opto/subnode.hpp"
    42 #include "opto/type.hpp"
    43 #include "runtime/sharedRuntime.hpp"
    46 //
    47 // Replace any references to "oldref" in inputs to "use" with "newref".
    48 // Returns the number of replacements made.
    49 //
    50 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
    51   int nreplacements = 0;
    52   uint req = use->req();
    53   for (uint j = 0; j < use->len(); j++) {
    54     Node *uin = use->in(j);
    55     if (uin == oldref) {
    56       if (j < req)
    57         use->set_req(j, newref);
    58       else
    59         use->set_prec(j, newref);
    60       nreplacements++;
    61     } else if (j >= req && uin == NULL) {
    62       break;
    63     }
    64   }
    65   return nreplacements;
    66 }
    68 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
    69   // Copy debug information and adjust JVMState information
    70   uint old_dbg_start = oldcall->tf()->domain()->cnt();
    71   uint new_dbg_start = newcall->tf()->domain()->cnt();
    72   int jvms_adj  = new_dbg_start - old_dbg_start;
    73   assert (new_dbg_start == newcall->req(), "argument count mismatch");
    75   // 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   const TypeOopPtr* res_type = NULL;
   703   if (res != NULL) { // Could be NULL when there are no users
   704     res_type = _igvn.type(res)->isa_oopptr();
   705   }
   707   if (res != NULL) {
   708     klass = res_type->klass();
   709     if (res_type->isa_instptr()) {
   710       // find the fields of the class which will be needed for safepoint debug information
   711       assert(klass->is_instance_klass(), "must be an instance klass.");
   712       iklass = klass->as_instance_klass();
   713       nfields = iklass->nof_nonstatic_fields();
   714     } else {
   715       // find the array's elements which will be needed for safepoint debug information
   716       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
   717       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
   718       elem_type = klass->as_array_klass()->element_type();
   719       basic_elem_type = elem_type->basic_type();
   720       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
   721       element_size = type2aelembytes(basic_elem_type);
   722     }
   723   }
   724   //
   725   // Process the safepoint uses
   726   //
   727   while (safepoints.length() > 0) {
   728     SafePointNode* sfpt = safepoints.pop();
   729     Node* mem = sfpt->memory();
   730     assert(sfpt->jvms() != NULL, "missed JVMS");
   731     // Fields of scalar objs are referenced only at the end
   732     // of regular debuginfo at the last (youngest) JVMS.
   733     // Record relative start index.
   734     uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
   735     SafePointScalarObjectNode* sobj = new (C) SafePointScalarObjectNode(res_type,
   736 #ifdef ASSERT
   737                                                  alloc,
   738 #endif
   739                                                  first_ind, nfields);
   740     sobj->init_req(0, C->root());
   741     transform_later(sobj);
   743     // Scan object's fields adding an input to the safepoint for each field.
   744     for (int j = 0; j < nfields; j++) {
   745       intptr_t offset;
   746       ciField* field = NULL;
   747       if (iklass != NULL) {
   748         field = iklass->nonstatic_field_at(j);
   749         offset = field->offset();
   750         elem_type = field->type();
   751         basic_elem_type = field->layout_type();
   752       } else {
   753         offset = array_base + j * (intptr_t)element_size;
   754       }
   756       const Type *field_type;
   757       // The next code is taken from Parse::do_get_xxx().
   758       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
   759         if (!elem_type->is_loaded()) {
   760           field_type = TypeInstPtr::BOTTOM;
   761         } else if (field != NULL && field->is_constant() && field->is_static()) {
   762           // This can happen if the constant oop is non-perm.
   763           ciObject* con = field->constant_value().as_object();
   764           // Do not "join" in the previous type; it doesn't add value,
   765           // and may yield a vacuous result if the field is of interface type.
   766           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
   767           assert(field_type != NULL, "field singleton type must be consistent");
   768         } else {
   769           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
   770         }
   771         if (UseCompressedOops) {
   772           field_type = field_type->make_narrowoop();
   773           basic_elem_type = T_NARROWOOP;
   774         }
   775       } else {
   776         field_type = Type::get_const_basic_type(basic_elem_type);
   777       }
   779       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
   781       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
   782       if (field_val == NULL) {
   783         // We weren't able to find a value for this field,
   784         // give up on eliminating this allocation.
   786         // Remove any extra entries we added to the safepoint.
   787         uint last = sfpt->req() - 1;
   788         for (int k = 0;  k < j; k++) {
   789           sfpt->del_req(last--);
   790         }
   791         // rollback processed safepoints
   792         while (safepoints_done.length() > 0) {
   793           SafePointNode* sfpt_done = safepoints_done.pop();
   794           // remove any extra entries we added to the safepoint
   795           last = sfpt_done->req() - 1;
   796           for (int k = 0;  k < nfields; k++) {
   797             sfpt_done->del_req(last--);
   798           }
   799           JVMState *jvms = sfpt_done->jvms();
   800           jvms->set_endoff(sfpt_done->req());
   801           // Now make a pass over the debug information replacing any references
   802           // to SafePointScalarObjectNode with the allocated object.
   803           int start = jvms->debug_start();
   804           int end   = jvms->debug_end();
   805           for (int i = start; i < end; i++) {
   806             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
   807               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
   808               if (scobj->first_index(jvms) == sfpt_done->req() &&
   809                   scobj->n_fields() == (uint)nfields) {
   810                 assert(scobj->alloc() == alloc, "sanity");
   811                 sfpt_done->set_req(i, res);
   812               }
   813             }
   814           }
   815         }
   816 #ifndef PRODUCT
   817         if (PrintEliminateAllocations) {
   818           if (field != NULL) {
   819             tty->print("=== At SafePoint node %d can't find value of Field: ",
   820                        sfpt->_idx);
   821             field->print();
   822             int field_idx = C->get_alias_index(field_addr_type);
   823             tty->print(" (alias_idx=%d)", field_idx);
   824           } else { // Array's element
   825             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
   826                        sfpt->_idx, j);
   827           }
   828           tty->print(", which prevents elimination of: ");
   829           if (res == NULL)
   830             alloc->dump();
   831           else
   832             res->dump();
   833         }
   834 #endif
   835         return false;
   836       }
   837       if (UseCompressedOops && field_type->isa_narrowoop()) {
   838         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
   839         // to be able scalar replace the allocation.
   840         if (field_val->is_EncodeP()) {
   841           field_val = field_val->in(1);
   842         } else {
   843           field_val = transform_later(new (C) DecodeNNode(field_val, field_val->get_ptr_type()));
   844         }
   845       }
   846       sfpt->add_req(field_val);
   847     }
   848     JVMState *jvms = sfpt->jvms();
   849     jvms->set_endoff(sfpt->req());
   850     // Now make a pass over the debug information replacing any references
   851     // to the allocated object with "sobj"
   852     int start = jvms->debug_start();
   853     int end   = jvms->debug_end();
   854     sfpt->replace_edges_in_range(res, sobj, start, end);
   855     safepoints_done.append_if_missing(sfpt); // keep it for rollback
   856   }
   857   return true;
   858 }
   860 // Process users of eliminated allocation.
   861 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
   862   Node* res = alloc->result_cast();
   863   if (res != NULL) {
   864     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
   865       Node *use = res->last_out(j);
   866       uint oc1 = res->outcnt();
   868       if (use->is_AddP()) {
   869         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
   870           Node *n = use->last_out(k);
   871           uint oc2 = use->outcnt();
   872           if (n->is_Store()) {
   873 #ifdef ASSERT
   874             // Verify that there is no dependent MemBarVolatile nodes,
   875             // they should be removed during IGVN, see MemBarNode::Ideal().
   876             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
   877                                        p < pmax; p++) {
   878               Node* mb = n->fast_out(p);
   879               assert(mb->is_Initialize() || !mb->is_MemBar() ||
   880                      mb->req() <= MemBarNode::Precedent ||
   881                      mb->in(MemBarNode::Precedent) != n,
   882                      "MemBarVolatile should be eliminated for non-escaping object");
   883             }
   884 #endif
   885             _igvn.replace_node(n, n->in(MemNode::Memory));
   886           } else {
   887             eliminate_card_mark(n);
   888           }
   889           k -= (oc2 - use->outcnt());
   890         }
   891       } else {
   892         eliminate_card_mark(use);
   893       }
   894       j -= (oc1 - res->outcnt());
   895     }
   896     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
   897     _igvn.remove_dead_node(res);
   898   }
   900   //
   901   // Process other users of allocation's projections
   902   //
   903   if (_resproj != NULL && _resproj->outcnt() != 0) {
   904     // First disconnect stores captured by Initialize node.
   905     // If Initialize node is eliminated first in the following code,
   906     // it will kill such stores and DUIterator_Last will assert.
   907     for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax);  j < jmax; j++) {
   908       Node *use = _resproj->fast_out(j);
   909       if (use->is_AddP()) {
   910         // raw memory addresses used only by the initialization
   911         _igvn.replace_node(use, C->top());
   912         --j; --jmax;
   913       }
   914     }
   915     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
   916       Node *use = _resproj->last_out(j);
   917       uint oc1 = _resproj->outcnt();
   918       if (use->is_Initialize()) {
   919         // Eliminate Initialize node.
   920         InitializeNode *init = use->as_Initialize();
   921         assert(init->outcnt() <= 2, "only a control and memory projection expected");
   922         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
   923         if (ctrl_proj != NULL) {
   924            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
   925           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
   926         }
   927         Node *mem_proj = init->proj_out(TypeFunc::Memory);
   928         if (mem_proj != NULL) {
   929           Node *mem = init->in(TypeFunc::Memory);
   930 #ifdef ASSERT
   931           if (mem->is_MergeMem()) {
   932             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
   933           } else {
   934             assert(mem == _memproj_fallthrough, "allocation memory projection");
   935           }
   936 #endif
   937           _igvn.replace_node(mem_proj, mem);
   938         }
   939       } else  {
   940         assert(false, "only Initialize or AddP expected");
   941       }
   942       j -= (oc1 - _resproj->outcnt());
   943     }
   944   }
   945   if (_fallthroughcatchproj != NULL) {
   946     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
   947   }
   948   if (_memproj_fallthrough != NULL) {
   949     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
   950   }
   951   if (_memproj_catchall != NULL) {
   952     _igvn.replace_node(_memproj_catchall, C->top());
   953   }
   954   if (_ioproj_fallthrough != NULL) {
   955     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
   956   }
   957   if (_ioproj_catchall != NULL) {
   958     _igvn.replace_node(_ioproj_catchall, C->top());
   959   }
   960   if (_catchallcatchproj != NULL) {
   961     _igvn.replace_node(_catchallcatchproj, C->top());
   962   }
   963 }
   965 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
   966   if (!EliminateAllocations || !alloc->_is_non_escaping) {
   967     return false;
   968   }
   969   Node* klass = alloc->in(AllocateNode::KlassNode);
   970   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
   971   Node* res = alloc->result_cast();
   972   // Eliminate boxing allocations which are not used
   973   // regardless scalar replacable status.
   974   bool boxing_alloc = C->eliminate_boxing() &&
   975                       tklass->klass()->is_instance_klass()  &&
   976                       tklass->klass()->as_instance_klass()->is_box_klass();
   977   if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
   978     return false;
   979   }
   981   extract_call_projections(alloc);
   983   GrowableArray <SafePointNode *> safepoints;
   984   if (!can_eliminate_allocation(alloc, safepoints)) {
   985     return false;
   986   }
   988   if (!alloc->_is_scalar_replaceable) {
   989     assert(res == NULL, "sanity");
   990     // We can only eliminate allocation if all debug info references
   991     // are already replaced with SafePointScalarObject because
   992     // we can't search for a fields value without instance_id.
   993     if (safepoints.length() > 0) {
   994       return false;
   995     }
   996   }
   998   if (!scalar_replacement(alloc, safepoints)) {
   999     return false;
  1002   CompileLog* log = C->log();
  1003   if (log != NULL) {
  1004     log->head("eliminate_allocation type='%d'",
  1005               log->identify(tklass->klass()));
  1006     JVMState* p = alloc->jvms();
  1007     while (p != NULL) {
  1008       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
  1009       p = p->caller();
  1011     log->tail("eliminate_allocation");
  1014   process_users_of_allocation(alloc);
  1016 #ifndef PRODUCT
  1017   if (PrintEliminateAllocations) {
  1018     if (alloc->is_AllocateArray())
  1019       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
  1020     else
  1021       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
  1023 #endif
  1025   return true;
  1028 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
  1029   // EA should remove all uses of non-escaping boxing node.
  1030   if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
  1031     return false;
  1034   extract_call_projections(boxing);
  1036   const TypeTuple* r = boxing->tf()->range();
  1037   assert(r->cnt() > TypeFunc::Parms, "sanity");
  1038   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
  1039   assert(t != NULL, "sanity");
  1041   CompileLog* log = C->log();
  1042   if (log != NULL) {
  1043     log->head("eliminate_boxing type='%d'",
  1044               log->identify(t->klass()));
  1045     JVMState* p = boxing->jvms();
  1046     while (p != NULL) {
  1047       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
  1048       p = p->caller();
  1050     log->tail("eliminate_boxing");
  1053   process_users_of_allocation(boxing);
  1055 #ifndef PRODUCT
  1056   if (PrintEliminateAllocations) {
  1057     tty->print("++++ Eliminated: %d ", boxing->_idx);
  1058     boxing->method()->print_short_name(tty);
  1059     tty->cr();
  1061 #endif
  1063   return true;
  1066 //---------------------------set_eden_pointers-------------------------
  1067 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
  1068   if (UseTLAB) {                // Private allocation: load from TLS
  1069     Node* thread = transform_later(new (C) ThreadLocalNode());
  1070     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
  1071     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
  1072     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
  1073     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
  1074   } else {                      // Shared allocation: load from globals
  1075     CollectedHeap* ch = Universe::heap();
  1076     address top_adr = (address)ch->top_addr();
  1077     address end_adr = (address)ch->end_addr();
  1078     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
  1079     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
  1084 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
  1085   Node* adr = basic_plus_adr(base, offset);
  1086   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
  1087   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
  1088   transform_later(value);
  1089   return value;
  1093 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
  1094   Node* adr = basic_plus_adr(base, offset);
  1095   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
  1096   transform_later(mem);
  1097   return mem;
  1100 //=============================================================================
  1101 //
  1102 //                              A L L O C A T I O N
  1103 //
  1104 // Allocation attempts to be fast in the case of frequent small objects.
  1105 // It breaks down like this:
  1106 //
  1107 // 1) Size in doublewords is computed.  This is a constant for objects and
  1108 // variable for most arrays.  Doubleword units are used to avoid size
  1109 // overflow of huge doubleword arrays.  We need doublewords in the end for
  1110 // rounding.
  1111 //
  1112 // 2) Size is checked for being 'too large'.  Too-large allocations will go
  1113 // the slow path into the VM.  The slow path can throw any required
  1114 // exceptions, and does all the special checks for very large arrays.  The
  1115 // size test can constant-fold away for objects.  For objects with
  1116 // finalizers it constant-folds the otherway: you always go slow with
  1117 // finalizers.
  1118 //
  1119 // 3) If NOT using TLABs, this is the contended loop-back point.
  1120 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
  1121 //
  1122 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
  1123 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
  1124 // "size*8" we always enter the VM, where "largish" is a constant picked small
  1125 // enough that there's always space between the eden max and 4Gig (old space is
  1126 // there so it's quite large) and large enough that the cost of entering the VM
  1127 // is dwarfed by the cost to initialize the space.
  1128 //
  1129 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
  1130 // down.  If contended, repeat at step 3.  If using TLABs normal-store
  1131 // adjusted heap top back down; there is no contention.
  1132 //
  1133 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
  1134 // fields.
  1135 //
  1136 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
  1137 // oop flavor.
  1138 //
  1139 //=============================================================================
  1140 // FastAllocateSizeLimit value is in DOUBLEWORDS.
  1141 // Allocations bigger than this always go the slow route.
  1142 // This value must be small enough that allocation attempts that need to
  1143 // trigger exceptions go the slow route.  Also, it must be small enough so
  1144 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
  1145 //=============================================================================j//
  1146 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
  1147 // The allocator will coalesce int->oop copies away.  See comment in
  1148 // coalesce.cpp about how this works.  It depends critically on the exact
  1149 // code shape produced here, so if you are changing this code shape
  1150 // make sure the GC info for the heap-top is correct in and around the
  1151 // slow-path call.
  1152 //
  1154 void PhaseMacroExpand::expand_allocate_common(
  1155             AllocateNode* alloc, // allocation node to be expanded
  1156             Node* length,  // array length for an array allocation
  1157             const TypeFunc* slow_call_type, // Type of slow call
  1158             address slow_call_address  // Address of slow call
  1162   Node* ctrl = alloc->in(TypeFunc::Control);
  1163   Node* mem  = alloc->in(TypeFunc::Memory);
  1164   Node* i_o  = alloc->in(TypeFunc::I_O);
  1165   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
  1166   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
  1167   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
  1169   assert(ctrl != NULL, "must have control");
  1170   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
  1171   // they will not be used if "always_slow" is set
  1172   enum { slow_result_path = 1, fast_result_path = 2 };
  1173   Node *result_region;
  1174   Node *result_phi_rawmem;
  1175   Node *result_phi_rawoop;
  1176   Node *result_phi_i_o;
  1178   // The initial slow comparison is a size check, the comparison
  1179   // we want to do is a BoolTest::gt
  1180   bool always_slow = false;
  1181   int tv = _igvn.find_int_con(initial_slow_test, -1);
  1182   if (tv >= 0) {
  1183     always_slow = (tv == 1);
  1184     initial_slow_test = NULL;
  1185   } else {
  1186     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
  1189   if (C->env()->dtrace_alloc_probes() ||
  1190       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
  1191                    (UseConcMarkSweepGC && CMSIncrementalMode))) {
  1192     // Force slow-path allocation
  1193     always_slow = true;
  1194     initial_slow_test = NULL;
  1198   enum { too_big_or_final_path = 1, need_gc_path = 2 };
  1199   Node *slow_region = NULL;
  1200   Node *toobig_false = ctrl;
  1202   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
  1203   // generate the initial test if necessary
  1204   if (initial_slow_test != NULL ) {
  1205     slow_region = new (C) RegionNode(3);
  1207     // Now make the initial failure test.  Usually a too-big test but
  1208     // might be a TRUE for finalizers or a fancy class check for
  1209     // newInstance0.
  1210     IfNode *toobig_iff = new (C) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
  1211     transform_later(toobig_iff);
  1212     // Plug the failing-too-big test into the slow-path region
  1213     Node *toobig_true = new (C) IfTrueNode( toobig_iff );
  1214     transform_later(toobig_true);
  1215     slow_region    ->init_req( too_big_or_final_path, toobig_true );
  1216     toobig_false = new (C) IfFalseNode( toobig_iff );
  1217     transform_later(toobig_false);
  1218   } else {         // No initial test, just fall into next case
  1219     toobig_false = ctrl;
  1220     debug_only(slow_region = NodeSentinel);
  1223   Node *slow_mem = mem;  // save the current memory state for slow path
  1224   // generate the fast allocation code unless we know that the initial test will always go slow
  1225   if (!always_slow) {
  1226     // Fast path modifies only raw memory.
  1227     if (mem->is_MergeMem()) {
  1228       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
  1231     Node* eden_top_adr;
  1232     Node* eden_end_adr;
  1234     set_eden_pointers(eden_top_adr, eden_end_adr);
  1236     // Load Eden::end.  Loop invariant and hoisted.
  1237     //
  1238     // Note: We set the control input on "eden_end" and "old_eden_top" when using
  1239     //       a TLAB to work around a bug where these values were being moved across
  1240     //       a safepoint.  These are not oops, so they cannot be include in the oop
  1241     //       map, but they can be changed by a GC.   The proper way to fix this would
  1242     //       be to set the raw memory state when generating a  SafepointNode.  However
  1243     //       this will require extensive changes to the loop optimization in order to
  1244     //       prevent a degradation of the optimization.
  1245     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
  1246     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
  1248     // allocate the Region and Phi nodes for the result
  1249     result_region = new (C) RegionNode(3);
  1250     result_phi_rawmem = new (C) PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1251     result_phi_rawoop = new (C) PhiNode(result_region, TypeRawPtr::BOTTOM);
  1252     result_phi_i_o    = new (C) PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
  1254     // We need a Region for the loop-back contended case.
  1255     enum { fall_in_path = 1, contended_loopback_path = 2 };
  1256     Node *contended_region;
  1257     Node *contended_phi_rawmem;
  1258     if (UseTLAB) {
  1259       contended_region = toobig_false;
  1260       contended_phi_rawmem = mem;
  1261     } else {
  1262       contended_region = new (C) RegionNode(3);
  1263       contended_phi_rawmem = new (C) PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  1264       // Now handle the passing-too-big test.  We fall into the contended
  1265       // loop-back merge point.
  1266       contended_region    ->init_req(fall_in_path, toobig_false);
  1267       contended_phi_rawmem->init_req(fall_in_path, mem);
  1268       transform_later(contended_region);
  1269       transform_later(contended_phi_rawmem);
  1272     // Load(-locked) the heap top.
  1273     // See note above concerning the control input when using a TLAB
  1274     Node *old_eden_top = UseTLAB
  1275       ? new (C) LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM)
  1276       : new (C) LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr);
  1278     transform_later(old_eden_top);
  1279     // Add to heap top to get a new heap top
  1280     Node *new_eden_top = new (C) AddPNode(top(), old_eden_top, size_in_bytes);
  1281     transform_later(new_eden_top);
  1282     // Check for needing a GC; compare against heap end
  1283     Node *needgc_cmp = new (C) CmpPNode(new_eden_top, eden_end);
  1284     transform_later(needgc_cmp);
  1285     Node *needgc_bol = new (C) BoolNode(needgc_cmp, BoolTest::ge);
  1286     transform_later(needgc_bol);
  1287     IfNode *needgc_iff = new (C) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
  1288     transform_later(needgc_iff);
  1290     // Plug the failing-heap-space-need-gc test into the slow-path region
  1291     Node *needgc_true = new (C) IfTrueNode(needgc_iff);
  1292     transform_later(needgc_true);
  1293     if (initial_slow_test) {
  1294       slow_region->init_req(need_gc_path, needgc_true);
  1295       // This completes all paths into the slow merge point
  1296       transform_later(slow_region);
  1297     } else {                      // No initial slow path needed!
  1298       // Just fall from the need-GC path straight into the VM call.
  1299       slow_region = needgc_true;
  1301     // No need for a GC.  Setup for the Store-Conditional
  1302     Node *needgc_false = new (C) IfFalseNode(needgc_iff);
  1303     transform_later(needgc_false);
  1305     // Grab regular I/O before optional prefetch may change it.
  1306     // Slow-path does no I/O so just set it to the original I/O.
  1307     result_phi_i_o->init_req(slow_result_path, i_o);
  1309     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
  1310                               old_eden_top, new_eden_top, length);
  1312     // Name successful fast-path variables
  1313     Node* fast_oop = old_eden_top;
  1314     Node* fast_oop_ctrl;
  1315     Node* fast_oop_rawmem;
  1317     // Store (-conditional) the modified eden top back down.
  1318     // StorePConditional produces flags for a test PLUS a modified raw
  1319     // memory state.
  1320     if (UseTLAB) {
  1321       Node* store_eden_top =
  1322         new (C) StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
  1323                               TypeRawPtr::BOTTOM, new_eden_top);
  1324       transform_later(store_eden_top);
  1325       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
  1326       fast_oop_rawmem = store_eden_top;
  1327     } else {
  1328       Node* store_eden_top =
  1329         new (C) StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
  1330                                          new_eden_top, fast_oop/*old_eden_top*/);
  1331       transform_later(store_eden_top);
  1332       Node *contention_check = new (C) BoolNode(store_eden_top, BoolTest::ne);
  1333       transform_later(contention_check);
  1334       store_eden_top = new (C) SCMemProjNode(store_eden_top);
  1335       transform_later(store_eden_top);
  1337       // If not using TLABs, check to see if there was contention.
  1338       IfNode *contention_iff = new (C) IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
  1339       transform_later(contention_iff);
  1340       Node *contention_true = new (C) IfTrueNode(contention_iff);
  1341       transform_later(contention_true);
  1342       // If contention, loopback and try again.
  1343       contended_region->init_req(contended_loopback_path, contention_true);
  1344       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
  1346       // Fast-path succeeded with no contention!
  1347       Node *contention_false = new (C) IfFalseNode(contention_iff);
  1348       transform_later(contention_false);
  1349       fast_oop_ctrl = contention_false;
  1351       // Bump total allocated bytes for this thread
  1352       Node* thread = new (C) ThreadLocalNode();
  1353       transform_later(thread);
  1354       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
  1355                                              in_bytes(JavaThread::allocated_bytes_offset()));
  1356       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
  1357                                     0, TypeLong::LONG, T_LONG);
  1358 #ifdef _LP64
  1359       Node* alloc_size = size_in_bytes;
  1360 #else
  1361       Node* alloc_size = new (C) ConvI2LNode(size_in_bytes);
  1362       transform_later(alloc_size);
  1363 #endif
  1364       Node* new_alloc_bytes = new (C) AddLNode(alloc_bytes, alloc_size);
  1365       transform_later(new_alloc_bytes);
  1366       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
  1367                                    0, new_alloc_bytes, T_LONG);
  1370     InitializeNode* init = alloc->initialization();
  1371     fast_oop_rawmem = initialize_object(alloc,
  1372                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
  1373                                         klass_node, length, size_in_bytes);
  1375     // If initialization is performed by an array copy, any required
  1376     // MemBarStoreStore was already added. If the object does not
  1377     // escape no need for a MemBarStoreStore. Otherwise we need a
  1378     // MemBarStoreStore so that stores that initialize this object
  1379     // can't be reordered with a subsequent store that makes this
  1380     // object accessible by other threads.
  1381     if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
  1382       if (init == NULL || init->req() < InitializeNode::RawStores) {
  1383         // No InitializeNode or no stores captured by zeroing
  1384         // elimination. Simply add the MemBarStoreStore after object
  1385         // initialization.
  1386         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
  1387         transform_later(mb);
  1389         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
  1390         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
  1391         fast_oop_ctrl = new (C) ProjNode(mb,TypeFunc::Control);
  1392         transform_later(fast_oop_ctrl);
  1393         fast_oop_rawmem = new (C) ProjNode(mb,TypeFunc::Memory);
  1394         transform_later(fast_oop_rawmem);
  1395       } else {
  1396         // Add the MemBarStoreStore after the InitializeNode so that
  1397         // all stores performing the initialization that were moved
  1398         // before the InitializeNode happen before the storestore
  1399         // barrier.
  1401         Node* init_ctrl = init->proj_out(TypeFunc::Control);
  1402         Node* init_mem = init->proj_out(TypeFunc::Memory);
  1404         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
  1405         transform_later(mb);
  1407         Node* ctrl = new (C) ProjNode(init,TypeFunc::Control);
  1408         transform_later(ctrl);
  1409         Node* mem = new (C) ProjNode(init,TypeFunc::Memory);
  1410         transform_later(mem);
  1412         // The MemBarStoreStore depends on control and memory coming
  1413         // from the InitializeNode
  1414         mb->init_req(TypeFunc::Memory, mem);
  1415         mb->init_req(TypeFunc::Control, ctrl);
  1417         ctrl = new (C) ProjNode(mb,TypeFunc::Control);
  1418         transform_later(ctrl);
  1419         mem = new (C) ProjNode(mb,TypeFunc::Memory);
  1420         transform_later(mem);
  1422         // All nodes that depended on the InitializeNode for control
  1423         // and memory must now depend on the MemBarNode that itself
  1424         // depends on the InitializeNode
  1425         _igvn.replace_node(init_ctrl, ctrl);
  1426         _igvn.replace_node(init_mem, mem);
  1430     if (C->env()->dtrace_extended_probes()) {
  1431       // Slow-path call
  1432       int size = TypeFunc::Parms + 2;
  1433       CallLeafNode *call = new (C) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
  1434                                                 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
  1435                                                 "dtrace_object_alloc",
  1436                                                 TypeRawPtr::BOTTOM);
  1438       // Get base of thread-local storage area
  1439       Node* thread = new (C) ThreadLocalNode();
  1440       transform_later(thread);
  1442       call->init_req(TypeFunc::Parms+0, thread);
  1443       call->init_req(TypeFunc::Parms+1, fast_oop);
  1444       call->init_req(TypeFunc::Control, fast_oop_ctrl);
  1445       call->init_req(TypeFunc::I_O    , top()); // does no i/o
  1446       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
  1447       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
  1448       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
  1449       transform_later(call);
  1450       fast_oop_ctrl = new (C) ProjNode(call,TypeFunc::Control);
  1451       transform_later(fast_oop_ctrl);
  1452       fast_oop_rawmem = new (C) ProjNode(call,TypeFunc::Memory);
  1453       transform_later(fast_oop_rawmem);
  1456     // Plug in the successful fast-path into the result merge point
  1457     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
  1458     result_phi_rawoop->init_req(fast_result_path, fast_oop);
  1459     result_phi_i_o   ->init_req(fast_result_path, i_o);
  1460     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
  1461   } else {
  1462     slow_region = ctrl;
  1463     result_phi_i_o = i_o; // Rename it to use in the following code.
  1466   // Generate slow-path call
  1467   CallNode *call = new (C) CallStaticJavaNode(slow_call_type, slow_call_address,
  1468                                OptoRuntime::stub_name(slow_call_address),
  1469                                alloc->jvms()->bci(),
  1470                                TypePtr::BOTTOM);
  1471   call->init_req( TypeFunc::Control, slow_region );
  1472   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
  1473   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
  1474   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
  1475   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
  1477   call->init_req(TypeFunc::Parms+0, klass_node);
  1478   if (length != NULL) {
  1479     call->init_req(TypeFunc::Parms+1, length);
  1482   // Copy debug information and adjust JVMState information, then replace
  1483   // allocate node with the call
  1484   copy_call_debug_info((CallNode *) alloc,  call);
  1485   if (!always_slow) {
  1486     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
  1487   } else {
  1488     // Hook i_o projection to avoid its elimination during allocation
  1489     // replacement (when only a slow call is generated).
  1490     call->set_req(TypeFunc::I_O, result_phi_i_o);
  1492   _igvn.replace_node(alloc, call);
  1493   transform_later(call);
  1495   // Identify the output projections from the allocate node and
  1496   // adjust any references to them.
  1497   // The control and io projections look like:
  1498   //
  1499   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
  1500   //  Allocate                   Catch
  1501   //        ^---Proj(io) <-------+   ^---CatchProj(io)
  1502   //
  1503   //  We are interested in the CatchProj nodes.
  1504   //
  1505   extract_call_projections(call);
  1507   // An allocate node has separate memory projections for the uses on
  1508   // the control and i_o paths. Replace the control memory projection with
  1509   // result_phi_rawmem (unless we are only generating a slow call when
  1510   // both memory projections are combined)
  1511   if (!always_slow && _memproj_fallthrough != NULL) {
  1512     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1513       Node *use = _memproj_fallthrough->fast_out(i);
  1514       _igvn.rehash_node_delayed(use);
  1515       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
  1516       // back up iterator
  1517       --i;
  1520   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
  1521   // _memproj_catchall so we end up with a call that has only 1 memory projection.
  1522   if (_memproj_catchall != NULL ) {
  1523     if (_memproj_fallthrough == NULL) {
  1524       _memproj_fallthrough = new (C) ProjNode(call, TypeFunc::Memory);
  1525       transform_later(_memproj_fallthrough);
  1527     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
  1528       Node *use = _memproj_catchall->fast_out(i);
  1529       _igvn.rehash_node_delayed(use);
  1530       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
  1531       // back up iterator
  1532       --i;
  1534     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
  1535     _igvn.remove_dead_node(_memproj_catchall);
  1538   // An allocate node has separate i_o projections for the uses on the control
  1539   // and i_o paths. Always replace the control i_o projection with result i_o
  1540   // otherwise incoming i_o become dead when only a slow call is generated
  1541   // (it is different from memory projections where both projections are
  1542   // combined in such case).
  1543   if (_ioproj_fallthrough != NULL) {
  1544     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
  1545       Node *use = _ioproj_fallthrough->fast_out(i);
  1546       _igvn.rehash_node_delayed(use);
  1547       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
  1548       // back up iterator
  1549       --i;
  1552   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
  1553   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
  1554   if (_ioproj_catchall != NULL ) {
  1555     if (_ioproj_fallthrough == NULL) {
  1556       _ioproj_fallthrough = new (C) ProjNode(call, TypeFunc::I_O);
  1557       transform_later(_ioproj_fallthrough);
  1559     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
  1560       Node *use = _ioproj_catchall->fast_out(i);
  1561       _igvn.rehash_node_delayed(use);
  1562       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
  1563       // back up iterator
  1564       --i;
  1566     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
  1567     _igvn.remove_dead_node(_ioproj_catchall);
  1570   // if we generated only a slow call, we are done
  1571   if (always_slow) {
  1572     // Now we can unhook i_o.
  1573     if (result_phi_i_o->outcnt() > 1) {
  1574       call->set_req(TypeFunc::I_O, top());
  1575     } else {
  1576       assert(result_phi_i_o->unique_ctrl_out() == call, "");
  1577       // Case of new array with negative size known during compilation.
  1578       // AllocateArrayNode::Ideal() optimization disconnect unreachable
  1579       // following code since call to runtime will throw exception.
  1580       // As result there will be no users of i_o after the call.
  1581       // Leave i_o attached to this call to avoid problems in preceding graph.
  1583     return;
  1587   if (_fallthroughcatchproj != NULL) {
  1588     ctrl = _fallthroughcatchproj->clone();
  1589     transform_later(ctrl);
  1590     _igvn.replace_node(_fallthroughcatchproj, result_region);
  1591   } else {
  1592     ctrl = top();
  1594   Node *slow_result;
  1595   if (_resproj == NULL) {
  1596     // no uses of the allocation result
  1597     slow_result = top();
  1598   } else {
  1599     slow_result = _resproj->clone();
  1600     transform_later(slow_result);
  1601     _igvn.replace_node(_resproj, result_phi_rawoop);
  1604   // Plug slow-path into result merge point
  1605   result_region    ->init_req( slow_result_path, ctrl );
  1606   result_phi_rawoop->init_req( slow_result_path, slow_result);
  1607   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
  1608   transform_later(result_region);
  1609   transform_later(result_phi_rawoop);
  1610   transform_later(result_phi_rawmem);
  1611   transform_later(result_phi_i_o);
  1612   // This completes all paths into the result merge point
  1616 // Helper for PhaseMacroExpand::expand_allocate_common.
  1617 // Initializes the newly-allocated storage.
  1618 Node*
  1619 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
  1620                                     Node* control, Node* rawmem, Node* object,
  1621                                     Node* klass_node, Node* length,
  1622                                     Node* size_in_bytes) {
  1623   InitializeNode* init = alloc->initialization();
  1624   // Store the klass & mark bits
  1625   Node* mark_node = NULL;
  1626   // For now only enable fast locking for non-array types
  1627   if (UseBiasedLocking && (length == NULL)) {
  1628     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
  1629   } else {
  1630     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
  1632   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
  1634   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
  1635   int header_size = alloc->minimum_header_size();  // conservatively small
  1637   // Array length
  1638   if (length != NULL) {         // Arrays need length field
  1639     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
  1640     // conservatively small header size:
  1641     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1642     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1643     if (k->is_array_klass())    // we know the exact header size in most cases:
  1644       header_size = Klass::layout_helper_header_size(k->layout_helper());
  1647   // Clear the object body, if necessary.
  1648   if (init == NULL) {
  1649     // The init has somehow disappeared; be cautious and clear everything.
  1650     //
  1651     // This can happen if a node is allocated but an uncommon trap occurs
  1652     // immediately.  In this case, the Initialize gets associated with the
  1653     // trap, and may be placed in a different (outer) loop, if the Allocate
  1654     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
  1655     // there can be two Allocates to one Initialize.  The answer in all these
  1656     // edge cases is safety first.  It is always safe to clear immediately
  1657     // within an Allocate, and then (maybe or maybe not) clear some more later.
  1658     if (!ZeroTLAB)
  1659       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
  1660                                             header_size, size_in_bytes,
  1661                                             &_igvn);
  1662   } else {
  1663     if (!init->is_complete()) {
  1664       // Try to win by zeroing only what the init does not store.
  1665       // We can also try to do some peephole optimizations,
  1666       // such as combining some adjacent subword stores.
  1667       rawmem = init->complete_stores(control, rawmem, object,
  1668                                      header_size, size_in_bytes, &_igvn);
  1670     // We have no more use for this link, since the AllocateNode goes away:
  1671     init->set_req(InitializeNode::RawAddress, top());
  1672     // (If we keep the link, it just confuses the register allocator,
  1673     // who thinks he sees a real use of the address by the membar.)
  1676   return rawmem;
  1679 // Generate prefetch instructions for next allocations.
  1680 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
  1681                                         Node*& contended_phi_rawmem,
  1682                                         Node* old_eden_top, Node* new_eden_top,
  1683                                         Node* length) {
  1684    enum { fall_in_path = 1, pf_path = 2 };
  1685    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
  1686       // Generate prefetch allocation with watermark check.
  1687       // As an allocation hits the watermark, we will prefetch starting
  1688       // at a "distance" away from watermark.
  1690       Node *pf_region = new (C) RegionNode(3);
  1691       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
  1692                                                 TypeRawPtr::BOTTOM );
  1693       // I/O is used for Prefetch
  1694       Node *pf_phi_abio = new (C) PhiNode( pf_region, Type::ABIO );
  1696       Node *thread = new (C) ThreadLocalNode();
  1697       transform_later(thread);
  1699       Node *eden_pf_adr = new (C) AddPNode( top()/*not oop*/, thread,
  1700                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
  1701       transform_later(eden_pf_adr);
  1703       Node *old_pf_wm = new (C) LoadPNode( needgc_false,
  1704                                    contended_phi_rawmem, eden_pf_adr,
  1705                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
  1706       transform_later(old_pf_wm);
  1708       // check against new_eden_top
  1709       Node *need_pf_cmp = new (C) CmpPNode( new_eden_top, old_pf_wm );
  1710       transform_later(need_pf_cmp);
  1711       Node *need_pf_bol = new (C) BoolNode( need_pf_cmp, BoolTest::ge );
  1712       transform_later(need_pf_bol);
  1713       IfNode *need_pf_iff = new (C) IfNode( needgc_false, need_pf_bol,
  1714                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
  1715       transform_later(need_pf_iff);
  1717       // true node, add prefetchdistance
  1718       Node *need_pf_true = new (C) IfTrueNode( need_pf_iff );
  1719       transform_later(need_pf_true);
  1721       Node *need_pf_false = new (C) IfFalseNode( need_pf_iff );
  1722       transform_later(need_pf_false);
  1724       Node *new_pf_wmt = new (C) AddPNode( top(), old_pf_wm,
  1725                                     _igvn.MakeConX(AllocatePrefetchDistance) );
  1726       transform_later(new_pf_wmt );
  1727       new_pf_wmt->set_req(0, need_pf_true);
  1729       Node *store_new_wmt = new (C) StorePNode( need_pf_true,
  1730                                        contended_phi_rawmem, eden_pf_adr,
  1731                                        TypeRawPtr::BOTTOM, new_pf_wmt );
  1732       transform_later(store_new_wmt);
  1734       // adding prefetches
  1735       pf_phi_abio->init_req( fall_in_path, i_o );
  1737       Node *prefetch_adr;
  1738       Node *prefetch;
  1739       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
  1740       uint step_size = AllocatePrefetchStepSize;
  1741       uint distance = 0;
  1743       for ( uint i = 0; i < lines; i++ ) {
  1744         prefetch_adr = new (C) AddPNode( old_pf_wm, new_pf_wmt,
  1745                                             _igvn.MakeConX(distance) );
  1746         transform_later(prefetch_adr);
  1747         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
  1748         transform_later(prefetch);
  1749         distance += step_size;
  1750         i_o = prefetch;
  1752       pf_phi_abio->set_req( pf_path, i_o );
  1754       pf_region->init_req( fall_in_path, need_pf_false );
  1755       pf_region->init_req( pf_path, need_pf_true );
  1757       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
  1758       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
  1760       transform_later(pf_region);
  1761       transform_later(pf_phi_rawmem);
  1762       transform_later(pf_phi_abio);
  1764       needgc_false = pf_region;
  1765       contended_phi_rawmem = pf_phi_rawmem;
  1766       i_o = pf_phi_abio;
  1767    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
  1768       // Insert a prefetch for each allocation.
  1769       // This code is used for Sparc with BIS.
  1770       Node *pf_region = new (C) RegionNode(3);
  1771       Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
  1772                                              TypeRawPtr::BOTTOM );
  1774       // Generate several prefetch instructions.
  1775       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
  1776       uint step_size = AllocatePrefetchStepSize;
  1777       uint distance = AllocatePrefetchDistance;
  1779       // Next cache address.
  1780       Node *cache_adr = new (C) AddPNode(old_eden_top, old_eden_top,
  1781                                             _igvn.MakeConX(distance));
  1782       transform_later(cache_adr);
  1783       cache_adr = new (C) CastP2XNode(needgc_false, cache_adr);
  1784       transform_later(cache_adr);
  1785       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
  1786       cache_adr = new (C) AndXNode(cache_adr, mask);
  1787       transform_later(cache_adr);
  1788       cache_adr = new (C) CastX2PNode(cache_adr);
  1789       transform_later(cache_adr);
  1791       // Prefetch
  1792       Node *prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
  1793       prefetch->set_req(0, needgc_false);
  1794       transform_later(prefetch);
  1795       contended_phi_rawmem = prefetch;
  1796       Node *prefetch_adr;
  1797       distance = step_size;
  1798       for ( uint i = 1; i < lines; i++ ) {
  1799         prefetch_adr = new (C) AddPNode( cache_adr, cache_adr,
  1800                                             _igvn.MakeConX(distance) );
  1801         transform_later(prefetch_adr);
  1802         prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
  1803         transform_later(prefetch);
  1804         distance += step_size;
  1805         contended_phi_rawmem = prefetch;
  1807    } else if( AllocatePrefetchStyle > 0 ) {
  1808       // Insert a prefetch for each allocation only on the fast-path
  1809       Node *prefetch_adr;
  1810       Node *prefetch;
  1811       // Generate several prefetch instructions.
  1812       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
  1813       uint step_size = AllocatePrefetchStepSize;
  1814       uint distance = AllocatePrefetchDistance;
  1815       for ( uint i = 0; i < lines; i++ ) {
  1816         prefetch_adr = new (C) AddPNode( old_eden_top, new_eden_top,
  1817                                             _igvn.MakeConX(distance) );
  1818         transform_later(prefetch_adr);
  1819         prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
  1820         // Do not let it float too high, since if eden_top == eden_end,
  1821         // both might be null.
  1822         if( i == 0 ) { // Set control for first prefetch, next follows it
  1823           prefetch->init_req(0, needgc_false);
  1825         transform_later(prefetch);
  1826         distance += step_size;
  1827         i_o = prefetch;
  1830    return i_o;
  1834 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
  1835   expand_allocate_common(alloc, NULL,
  1836                          OptoRuntime::new_instance_Type(),
  1837                          OptoRuntime::new_instance_Java());
  1840 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
  1841   Node* length = alloc->in(AllocateNode::ALength);
  1842   InitializeNode* init = alloc->initialization();
  1843   Node* klass_node = alloc->in(AllocateNode::KlassNode);
  1844   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
  1845   address slow_call_address;  // Address of slow call
  1846   if (init != NULL && init->is_complete_with_arraycopy() &&
  1847       k->is_type_array_klass()) {
  1848     // Don't zero type array during slow allocation in VM since
  1849     // it will be initialized later by arraycopy in compiled code.
  1850     slow_call_address = OptoRuntime::new_array_nozero_Java();
  1851   } else {
  1852     slow_call_address = OptoRuntime::new_array_Java();
  1854   expand_allocate_common(alloc, length,
  1855                          OptoRuntime::new_array_Type(),
  1856                          slow_call_address);
  1859 //-------------------mark_eliminated_box----------------------------------
  1860 //
  1861 // During EA obj may point to several objects but after few ideal graph
  1862 // transformations (CCP) it may point to only one non escaping object
  1863 // (but still using phi), corresponding locks and unlocks will be marked
  1864 // for elimination. Later obj could be replaced with a new node (new phi)
  1865 // and which does not have escape information. And later after some graph
  1866 // reshape other locks and unlocks (which were not marked for elimination
  1867 // before) are connected to this new obj (phi) but they still will not be
  1868 // marked for elimination since new obj has no escape information.
  1869 // Mark all associated (same box and obj) lock and unlock nodes for
  1870 // elimination if some of them marked already.
  1871 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
  1872   if (oldbox->as_BoxLock()->is_eliminated())
  1873     return; // This BoxLock node was processed already.
  1875   // New implementation (EliminateNestedLocks) has separate BoxLock
  1876   // node for each locked region so mark all associated locks/unlocks as
  1877   // eliminated even if different objects are referenced in one locked region
  1878   // (for example, OSR compilation of nested loop inside locked scope).
  1879   if (EliminateNestedLocks ||
  1880       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
  1881     // Box is used only in one lock region. Mark this box as eliminated.
  1882     _igvn.hash_delete(oldbox);
  1883     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
  1884     _igvn.hash_insert(oldbox);
  1886     for (uint i = 0; i < oldbox->outcnt(); i++) {
  1887       Node* u = oldbox->raw_out(i);
  1888       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
  1889         AbstractLockNode* alock = u->as_AbstractLock();
  1890         // Check lock's box since box could be referenced by Lock's debug info.
  1891         if (alock->box_node() == oldbox) {
  1892           // Mark eliminated all related locks and unlocks.
  1893           alock->set_non_esc_obj();
  1897     return;
  1900   // Create new "eliminated" BoxLock node and use it in monitor debug info
  1901   // instead of oldbox for the same object.
  1902   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
  1904   // Note: BoxLock node is marked eliminated only here and it is used
  1905   // to indicate that all associated lock and unlock nodes are marked
  1906   // for elimination.
  1907   newbox->set_eliminated();
  1908   transform_later(newbox);
  1910   // Replace old box node with new box for all users of the same object.
  1911   for (uint i = 0; i < oldbox->outcnt();) {
  1912     bool next_edge = true;
  1914     Node* u = oldbox->raw_out(i);
  1915     if (u->is_AbstractLock()) {
  1916       AbstractLockNode* alock = u->as_AbstractLock();
  1917       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
  1918         // Replace Box and mark eliminated all related locks and unlocks.
  1919         alock->set_non_esc_obj();
  1920         _igvn.rehash_node_delayed(alock);
  1921         alock->set_box_node(newbox);
  1922         next_edge = false;
  1925     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
  1926       FastLockNode* flock = u->as_FastLock();
  1927       assert(flock->box_node() == oldbox, "sanity");
  1928       _igvn.rehash_node_delayed(flock);
  1929       flock->set_box_node(newbox);
  1930       next_edge = false;
  1933     // Replace old box in monitor debug info.
  1934     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
  1935       SafePointNode* sfn = u->as_SafePoint();
  1936       JVMState* youngest_jvms = sfn->jvms();
  1937       int max_depth = youngest_jvms->depth();
  1938       for (int depth = 1; depth <= max_depth; depth++) {
  1939         JVMState* jvms = youngest_jvms->of_depth(depth);
  1940         int num_mon  = jvms->nof_monitors();
  1941         // Loop over monitors
  1942         for (int idx = 0; idx < num_mon; idx++) {
  1943           Node* obj_node = sfn->monitor_obj(jvms, idx);
  1944           Node* box_node = sfn->monitor_box(jvms, idx);
  1945           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
  1946             int j = jvms->monitor_box_offset(idx);
  1947             _igvn.replace_input_of(u, j, newbox);
  1948             next_edge = false;
  1953     if (next_edge) i++;
  1957 //-----------------------mark_eliminated_locking_nodes-----------------------
  1958 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
  1959   if (EliminateNestedLocks) {
  1960     if (alock->is_nested()) {
  1961        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
  1962        return;
  1963     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
  1964       // Only Lock node has JVMState needed here.
  1965       if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
  1966         // Mark eliminated related nested locks and unlocks.
  1967         Node* obj = alock->obj_node();
  1968         BoxLockNode* box_node = alock->box_node()->as_BoxLock();
  1969         assert(!box_node->is_eliminated(), "should not be marked yet");
  1970         // Note: BoxLock node is marked eliminated only here
  1971         // and it is used to indicate that all associated lock
  1972         // and unlock nodes are marked for elimination.
  1973         box_node->set_eliminated(); // Box's hash is always NO_HASH here
  1974         for (uint i = 0; i < box_node->outcnt(); i++) {
  1975           Node* u = box_node->raw_out(i);
  1976           if (u->is_AbstractLock()) {
  1977             alock = u->as_AbstractLock();
  1978             if (alock->box_node() == box_node) {
  1979               // Verify that this Box is referenced only by related locks.
  1980               assert(alock->obj_node()->eqv_uncast(obj), "");
  1981               // Mark all related locks and unlocks.
  1982               alock->set_nested();
  1987       return;
  1989     // Process locks for non escaping object
  1990     assert(alock->is_non_esc_obj(), "");
  1991   } // EliminateNestedLocks
  1993   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
  1994     // Look for all locks of this object and mark them and
  1995     // corresponding BoxLock nodes as eliminated.
  1996     Node* obj = alock->obj_node();
  1997     for (uint j = 0; j < obj->outcnt(); j++) {
  1998       Node* o = obj->raw_out(j);
  1999       if (o->is_AbstractLock() &&
  2000           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
  2001         alock = o->as_AbstractLock();
  2002         Node* box = alock->box_node();
  2003         // Replace old box node with new eliminated box for all users
  2004         // of the same object and mark related locks as eliminated.
  2005         mark_eliminated_box(box, obj);
  2011 // we have determined that this lock/unlock can be eliminated, we simply
  2012 // eliminate the node without expanding it.
  2013 //
  2014 // Note:  The membar's associated with the lock/unlock are currently not
  2015 //        eliminated.  This should be investigated as a future enhancement.
  2016 //
  2017 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
  2019   if (!alock->is_eliminated()) {
  2020     return false;
  2022 #ifdef ASSERT
  2023   if (!alock->is_coarsened()) {
  2024     // Check that new "eliminated" BoxLock node is created.
  2025     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
  2026     assert(oldbox->is_eliminated(), "should be done already");
  2028 #endif
  2029   CompileLog* log = C->log();
  2030   if (log != NULL) {
  2031     log->head("eliminate_lock lock='%d'",
  2032               alock->is_Lock());
  2033     JVMState* p = alock->jvms();
  2034     while (p != NULL) {
  2035       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
  2036       p = p->caller();
  2038     log->tail("eliminate_lock");
  2041   #ifndef PRODUCT
  2042   if (PrintEliminateLocks) {
  2043     if (alock->is_Lock()) {
  2044       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
  2045     } else {
  2046       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
  2049   #endif
  2051   Node* mem  = alock->in(TypeFunc::Memory);
  2052   Node* ctrl = alock->in(TypeFunc::Control);
  2054   extract_call_projections(alock);
  2055   // There are 2 projections from the lock.  The lock node will
  2056   // be deleted when its last use is subsumed below.
  2057   assert(alock->outcnt() == 2 &&
  2058          _fallthroughproj != NULL &&
  2059          _memproj_fallthrough != NULL,
  2060          "Unexpected projections from Lock/Unlock");
  2062   Node* fallthroughproj = _fallthroughproj;
  2063   Node* memproj_fallthrough = _memproj_fallthrough;
  2065   // The memory projection from a lock/unlock is RawMem
  2066   // The input to a Lock is merged memory, so extract its RawMem input
  2067   // (unless the MergeMem has been optimized away.)
  2068   if (alock->is_Lock()) {
  2069     // Seach for MemBarAcquireLock node and delete it also.
  2070     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
  2071     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
  2072     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
  2073     Node* memproj = membar->proj_out(TypeFunc::Memory);
  2074     _igvn.replace_node(ctrlproj, fallthroughproj);
  2075     _igvn.replace_node(memproj, memproj_fallthrough);
  2077     // Delete FastLock node also if this Lock node is unique user
  2078     // (a loop peeling may clone a Lock node).
  2079     Node* flock = alock->as_Lock()->fastlock_node();
  2080     if (flock->outcnt() == 1) {
  2081       assert(flock->unique_out() == alock, "sanity");
  2082       _igvn.replace_node(flock, top());
  2086   // Seach for MemBarReleaseLock node and delete it also.
  2087   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
  2088       ctrl->in(0)->is_MemBar()) {
  2089     MemBarNode* membar = ctrl->in(0)->as_MemBar();
  2090     assert(membar->Opcode() == Op_MemBarReleaseLock &&
  2091            mem->is_Proj() && membar == mem->in(0), "");
  2092     _igvn.replace_node(fallthroughproj, ctrl);
  2093     _igvn.replace_node(memproj_fallthrough, mem);
  2094     fallthroughproj = ctrl;
  2095     memproj_fallthrough = mem;
  2096     ctrl = membar->in(TypeFunc::Control);
  2097     mem  = membar->in(TypeFunc::Memory);
  2100   _igvn.replace_node(fallthroughproj, ctrl);
  2101   _igvn.replace_node(memproj_fallthrough, mem);
  2102   return true;
  2106 //------------------------------expand_lock_node----------------------
  2107 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
  2109   Node* ctrl = lock->in(TypeFunc::Control);
  2110   Node* mem = lock->in(TypeFunc::Memory);
  2111   Node* obj = lock->obj_node();
  2112   Node* box = lock->box_node();
  2113   Node* flock = lock->fastlock_node();
  2115   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
  2117   // Make the merge point
  2118   Node *region;
  2119   Node *mem_phi;
  2120   Node *slow_path;
  2122   if (UseOptoBiasInlining) {
  2123     /*
  2124      *  See the full description in MacroAssembler::biased_locking_enter().
  2126      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
  2127      *    // The object is biased.
  2128      *    proto_node = klass->prototype_header;
  2129      *    o_node = thread | proto_node;
  2130      *    x_node = o_node ^ mark_word;
  2131      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
  2132      *      // Done.
  2133      *    } else {
  2134      *      if( (x_node & biased_lock_mask) != 0 ) {
  2135      *        // The klass's prototype header is no longer biased.
  2136      *        cas(&mark_word, mark_word, proto_node)
  2137      *        goto cas_lock;
  2138      *      } else {
  2139      *        // The klass's prototype header is still biased.
  2140      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
  2141      *          old = mark_word;
  2142      *          new = o_node;
  2143      *        } else {
  2144      *          // Different thread or anonymous biased.
  2145      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
  2146      *          new = thread | old;
  2147      *        }
  2148      *        // Try to rebias.
  2149      *        if( cas(&mark_word, old, new) == 0 ) {
  2150      *          // Done.
  2151      *        } else {
  2152      *          goto slow_path; // Failed.
  2153      *        }
  2154      *      }
  2155      *    }
  2156      *  } else {
  2157      *    // The object is not biased.
  2158      *    cas_lock:
  2159      *    if( FastLock(obj) == 0 ) {
  2160      *      // Done.
  2161      *    } else {
  2162      *      slow_path:
  2163      *      OptoRuntime::complete_monitor_locking_Java(obj);
  2164      *    }
  2165      *  }
  2166      */
  2168     region  = new (C) RegionNode(5);
  2169     // create a Phi for the memory state
  2170     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2172     Node* fast_lock_region  = new (C) RegionNode(3);
  2173     Node* fast_lock_mem_phi = new (C) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2175     // First, check mark word for the biased lock pattern.
  2176     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  2178     // Get fast path - mark word has the biased lock pattern.
  2179     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
  2180                          markOopDesc::biased_lock_mask_in_place,
  2181                          markOopDesc::biased_lock_pattern, true);
  2182     // fast_lock_region->in(1) is set to slow path.
  2183     fast_lock_mem_phi->init_req(1, mem);
  2185     // Now check that the lock is biased to the current thread and has
  2186     // the same epoch and bias as Klass::_prototype_header.
  2188     // Special-case a fresh allocation to avoid building nodes:
  2189     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
  2190     if (klass_node == NULL) {
  2191       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
  2192       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
  2193 #ifdef _LP64
  2194       if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
  2195         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
  2196         klass_node->in(1)->init_req(0, ctrl);
  2197       } else
  2198 #endif
  2199       klass_node->init_req(0, ctrl);
  2201     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
  2203     Node* thread = transform_later(new (C) ThreadLocalNode());
  2204     Node* cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
  2205     Node* o_node = transform_later(new (C) OrXNode(cast_thread, proto_node));
  2206     Node* x_node = transform_later(new (C) XorXNode(o_node, mark_node));
  2208     // Get slow path - mark word does NOT match the value.
  2209     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
  2210                                       (~markOopDesc::age_mask_in_place), 0);
  2211     // region->in(3) is set to fast path - the object is biased to the current thread.
  2212     mem_phi->init_req(3, mem);
  2215     // Mark word does NOT match the value (thread | Klass::_prototype_header).
  2218     // First, check biased pattern.
  2219     // Get fast path - _prototype_header has the same biased lock pattern.
  2220     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
  2221                           markOopDesc::biased_lock_mask_in_place, 0, true);
  2223     not_biased_ctrl = fast_lock_region->in(2); // Slow path
  2224     // fast_lock_region->in(2) - the prototype header is no longer biased
  2225     // and we have to revoke the bias on this object.
  2226     // We are going to try to reset the mark of this object to the prototype
  2227     // value and fall through to the CAS-based locking scheme.
  2228     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
  2229     Node* cas = new (C) StoreXConditionalNode(not_biased_ctrl, mem, adr,
  2230                                               proto_node, mark_node);
  2231     transform_later(cas);
  2232     Node* proj = transform_later( new (C) SCMemProjNode(cas));
  2233     fast_lock_mem_phi->init_req(2, proj);
  2236     // Second, check epoch bits.
  2237     Node* rebiased_region  = new (C) RegionNode(3);
  2238     Node* old_phi = new (C) PhiNode( rebiased_region, TypeX_X);
  2239     Node* new_phi = new (C) PhiNode( rebiased_region, TypeX_X);
  2241     // Get slow path - mark word does NOT match epoch bits.
  2242     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
  2243                                       markOopDesc::epoch_mask_in_place, 0);
  2244     // The epoch of the current bias is not valid, attempt to rebias the object
  2245     // toward the current thread.
  2246     rebiased_region->init_req(2, epoch_ctrl);
  2247     old_phi->init_req(2, mark_node);
  2248     new_phi->init_req(2, o_node);
  2250     // rebiased_region->in(1) is set to fast path.
  2251     // The epoch of the current bias is still valid but we know
  2252     // nothing about the owner; it might be set or it might be clear.
  2253     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
  2254                              markOopDesc::age_mask_in_place |
  2255                              markOopDesc::epoch_mask_in_place);
  2256     Node* old = transform_later(new (C) AndXNode(mark_node, cmask));
  2257     cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
  2258     Node* new_mark = transform_later(new (C) OrXNode(cast_thread, old));
  2259     old_phi->init_req(1, old);
  2260     new_phi->init_req(1, new_mark);
  2262     transform_later(rebiased_region);
  2263     transform_later(old_phi);
  2264     transform_later(new_phi);
  2266     // Try to acquire the bias of the object using an atomic operation.
  2267     // If this fails we will go in to the runtime to revoke the object's bias.
  2268     cas = new (C) StoreXConditionalNode(rebiased_region, mem, adr,
  2269                                            new_phi, old_phi);
  2270     transform_later(cas);
  2271     proj = transform_later( new (C) SCMemProjNode(cas));
  2273     // Get slow path - Failed to CAS.
  2274     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
  2275     mem_phi->init_req(4, proj);
  2276     // region->in(4) is set to fast path - the object is rebiased to the current thread.
  2278     // Failed to CAS.
  2279     slow_path  = new (C) RegionNode(3);
  2280     Node *slow_mem = new (C) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
  2282     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
  2283     slow_mem->init_req(1, proj);
  2285     // Call CAS-based locking scheme (FastLock node).
  2287     transform_later(fast_lock_region);
  2288     transform_later(fast_lock_mem_phi);
  2290     // Get slow path - FastLock failed to lock the object.
  2291     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
  2292     mem_phi->init_req(2, fast_lock_mem_phi);
  2293     // region->in(2) is set to fast path - the object is locked to the current thread.
  2295     slow_path->init_req(2, ctrl); // Capture slow-control
  2296     slow_mem->init_req(2, fast_lock_mem_phi);
  2298     transform_later(slow_path);
  2299     transform_later(slow_mem);
  2300     // Reset lock's memory edge.
  2301     lock->set_req(TypeFunc::Memory, slow_mem);
  2303   } else {
  2304     region  = new (C) RegionNode(3);
  2305     // create a Phi for the memory state
  2306     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2308     // Optimize test; set region slot 2
  2309     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
  2310     mem_phi->init_req(2, mem);
  2313   // Make slow path call
  2314   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
  2316   extract_call_projections(call);
  2318   // Slow path can only throw asynchronous exceptions, which are always
  2319   // de-opted.  So the compiler thinks the slow-call can never throw an
  2320   // exception.  If it DOES throw an exception we would need the debug
  2321   // info removed first (since if it throws there is no monitor).
  2322   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  2323            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  2325   // Capture slow path
  2326   // disconnect fall-through projection from call and create a new one
  2327   // hook up users of fall-through projection to region
  2328   Node *slow_ctrl = _fallthroughproj->clone();
  2329   transform_later(slow_ctrl);
  2330   _igvn.hash_delete(_fallthroughproj);
  2331   _fallthroughproj->disconnect_inputs(NULL, C);
  2332   region->init_req(1, slow_ctrl);
  2333   // region inputs are now complete
  2334   transform_later(region);
  2335   _igvn.replace_node(_fallthroughproj, region);
  2337   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
  2338   mem_phi->init_req(1, memproj );
  2339   transform_later(mem_phi);
  2340   _igvn.replace_node(_memproj_fallthrough, mem_phi);
  2343 //------------------------------expand_unlock_node----------------------
  2344 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
  2346   Node* ctrl = unlock->in(TypeFunc::Control);
  2347   Node* mem = unlock->in(TypeFunc::Memory);
  2348   Node* obj = unlock->obj_node();
  2349   Node* box = unlock->box_node();
  2351   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
  2353   // No need for a null check on unlock
  2355   // Make the merge point
  2356   Node *region;
  2357   Node *mem_phi;
  2359   if (UseOptoBiasInlining) {
  2360     // Check for biased locking unlock case, which is a no-op.
  2361     // See the full description in MacroAssembler::biased_locking_exit().
  2362     region  = new (C) RegionNode(4);
  2363     // create a Phi for the memory state
  2364     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2365     mem_phi->init_req(3, mem);
  2367     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
  2368     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
  2369                          markOopDesc::biased_lock_mask_in_place,
  2370                          markOopDesc::biased_lock_pattern);
  2371   } else {
  2372     region  = new (C) RegionNode(3);
  2373     // create a Phi for the memory state
  2374     mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
  2377   FastUnlockNode *funlock = new (C) FastUnlockNode( ctrl, obj, box );
  2378   funlock = transform_later( funlock )->as_FastUnlock();
  2379   // Optimize test; set region slot 2
  2380   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
  2382   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 );
  2384   extract_call_projections(call);
  2386   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
  2387            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
  2389   // No exceptions for unlocking
  2390   // Capture slow path
  2391   // disconnect fall-through projection from call and create a new one
  2392   // hook up users of fall-through projection to region
  2393   Node *slow_ctrl = _fallthroughproj->clone();
  2394   transform_later(slow_ctrl);
  2395   _igvn.hash_delete(_fallthroughproj);
  2396   _fallthroughproj->disconnect_inputs(NULL, C);
  2397   region->init_req(1, slow_ctrl);
  2398   // region inputs are now complete
  2399   transform_later(region);
  2400   _igvn.replace_node(_fallthroughproj, region);
  2402   Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
  2403   mem_phi->init_req(1, memproj );
  2404   mem_phi->init_req(2, mem);
  2405   transform_later(mem_phi);
  2406   _igvn.replace_node(_memproj_fallthrough, mem_phi);
  2409 //---------------------------eliminate_macro_nodes----------------------
  2410 // Eliminate scalar replaced allocations and associated locks.
  2411 void PhaseMacroExpand::eliminate_macro_nodes() {
  2412   if (C->macro_count() == 0)
  2413     return;
  2415   // First, attempt to eliminate locks
  2416   int cnt = C->macro_count();
  2417   for (int i=0; i < cnt; i++) {
  2418     Node *n = C->macro_node(i);
  2419     if (n->is_AbstractLock()) { // Lock and Unlock nodes
  2420       // Before elimination mark all associated (same box and obj)
  2421       // lock and unlock nodes.
  2422       mark_eliminated_locking_nodes(n->as_AbstractLock());
  2425   bool progress = true;
  2426   while (progress) {
  2427     progress = false;
  2428     for (int i = C->macro_count(); i > 0; i--) {
  2429       Node * n = C->macro_node(i-1);
  2430       bool success = false;
  2431       debug_only(int old_macro_count = C->macro_count(););
  2432       if (n->is_AbstractLock()) {
  2433         success = eliminate_locking_node(n->as_AbstractLock());
  2435       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2436       progress = progress || success;
  2439   // Next, attempt to eliminate allocations
  2440   progress = true;
  2441   while (progress) {
  2442     progress = false;
  2443     for (int i = C->macro_count(); i > 0; i--) {
  2444       Node * n = C->macro_node(i-1);
  2445       bool success = false;
  2446       debug_only(int old_macro_count = C->macro_count(););
  2447       switch (n->class_id()) {
  2448       case Node::Class_Allocate:
  2449       case Node::Class_AllocateArray:
  2450         success = eliminate_allocate_node(n->as_Allocate());
  2451         break;
  2452       case Node::Class_CallStaticJava:
  2453         success = eliminate_boxing_node(n->as_CallStaticJava());
  2454         break;
  2455       case Node::Class_Lock:
  2456       case Node::Class_Unlock:
  2457         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
  2458         break;
  2459       default:
  2460         assert(n->Opcode() == Op_LoopLimit ||
  2461                n->Opcode() == Op_Opaque1   ||
  2462                n->Opcode() == Op_Opaque2, "unknown node type in macro list");
  2464       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2465       progress = progress || success;
  2470 //------------------------------expand_macro_nodes----------------------
  2471 //  Returns true if a failure occurred.
  2472 bool PhaseMacroExpand::expand_macro_nodes() {
  2473   // Last attempt to eliminate macro nodes.
  2474   eliminate_macro_nodes();
  2476   // Make sure expansion will not cause node limit to be exceeded.
  2477   // Worst case is a macro node gets expanded into about 50 nodes.
  2478   // Allow 50% more for optimization.
  2479   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
  2480     return true;
  2482   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
  2483   bool progress = true;
  2484   while (progress) {
  2485     progress = false;
  2486     for (int i = C->macro_count(); i > 0; i--) {
  2487       Node * n = C->macro_node(i-1);
  2488       bool success = false;
  2489       debug_only(int old_macro_count = C->macro_count(););
  2490       if (n->Opcode() == Op_LoopLimit) {
  2491         // Remove it from macro list and put on IGVN worklist to optimize.
  2492         C->remove_macro_node(n);
  2493         _igvn._worklist.push(n);
  2494         success = true;
  2495       } else if (n->Opcode() == Op_CallStaticJava) {
  2496         // Remove it from macro list and put on IGVN worklist to optimize.
  2497         C->remove_macro_node(n);
  2498         _igvn._worklist.push(n);
  2499         success = true;
  2500       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
  2501         _igvn.replace_node(n, n->in(1));
  2502         success = true;
  2504       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
  2505       progress = progress || success;
  2509   // expand "macro" nodes
  2510   // nodes are removed from the macro list as they are processed
  2511   while (C->macro_count() > 0) {
  2512     int macro_count = C->macro_count();
  2513     Node * n = C->macro_node(macro_count-1);
  2514     assert(n->is_macro(), "only macro nodes expected here");
  2515     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
  2516       // node is unreachable, so don't try to expand it
  2517       C->remove_macro_node(n);
  2518       continue;
  2520     switch (n->class_id()) {
  2521     case Node::Class_Allocate:
  2522       expand_allocate(n->as_Allocate());
  2523       break;
  2524     case Node::Class_AllocateArray:
  2525       expand_allocate_array(n->as_AllocateArray());
  2526       break;
  2527     case Node::Class_Lock:
  2528       expand_lock_node(n->as_Lock());
  2529       break;
  2530     case Node::Class_Unlock:
  2531       expand_unlock_node(n->as_Unlock());
  2532       break;
  2533     default:
  2534       assert(false, "unknown node type in macro list");
  2536     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
  2537     if (C->failing())  return true;
  2540   _igvn.set_delay_transform(false);
  2541   _igvn.optimize();
  2542   if (C->failing())  return true;
  2543   return false;

mercurial