src/share/vm/opto/callnode.cpp

Thu, 05 Feb 2009 11:42:10 -0800

author
never
date
Thu, 05 Feb 2009 11:42:10 -0800
changeset 979
82a980778b92
parent 895
424f9bfe6b96
child 1036
523ded093c31
permissions
-rw-r--r--

6793828: G1: invariant: queues are empty when activated
Reviewed-by: jrose, kvn

     1 /*
     2  * Copyright 1997-2008 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 // Portions of code courtesy of Clifford Click
    27 // Optimization - Graph Style
    29 #include "incls/_precompiled.incl"
    30 #include "incls/_callnode.cpp.incl"
    32 //=============================================================================
    33 uint StartNode::size_of() const { return sizeof(*this); }
    34 uint StartNode::cmp( const Node &n ) const
    35 { return _domain == ((StartNode&)n)._domain; }
    36 const Type *StartNode::bottom_type() const { return _domain; }
    37 const Type *StartNode::Value(PhaseTransform *phase) const { return _domain; }
    38 #ifndef PRODUCT
    39 void StartNode::dump_spec(outputStream *st) const { st->print(" #"); _domain->dump_on(st);}
    40 #endif
    42 //------------------------------Ideal------------------------------------------
    43 Node *StartNode::Ideal(PhaseGVN *phase, bool can_reshape){
    44   return remove_dead_region(phase, can_reshape) ? this : NULL;
    45 }
    47 //------------------------------calling_convention-----------------------------
    48 void StartNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
    49   Matcher::calling_convention( sig_bt, parm_regs, argcnt, false );
    50 }
    52 //------------------------------Registers--------------------------------------
    53 const RegMask &StartNode::in_RegMask(uint) const {
    54   return RegMask::Empty;
    55 }
    57 //------------------------------match------------------------------------------
    58 // Construct projections for incoming parameters, and their RegMask info
    59 Node *StartNode::match( const ProjNode *proj, const Matcher *match ) {
    60   switch (proj->_con) {
    61   case TypeFunc::Control:
    62   case TypeFunc::I_O:
    63   case TypeFunc::Memory:
    64     return new (match->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
    65   case TypeFunc::FramePtr:
    66     return new (match->C, 1) MachProjNode(this,proj->_con,Matcher::c_frame_ptr_mask, Op_RegP);
    67   case TypeFunc::ReturnAdr:
    68     return new (match->C, 1) MachProjNode(this,proj->_con,match->_return_addr_mask,Op_RegP);
    69   case TypeFunc::Parms:
    70   default: {
    71       uint parm_num = proj->_con - TypeFunc::Parms;
    72       const Type *t = _domain->field_at(proj->_con);
    73       if (t->base() == Type::Half)  // 2nd half of Longs and Doubles
    74         return new (match->C, 1) ConNode(Type::TOP);
    75       uint ideal_reg = Matcher::base2reg[t->base()];
    76       RegMask &rm = match->_calling_convention_mask[parm_num];
    77       return new (match->C, 1) MachProjNode(this,proj->_con,rm,ideal_reg);
    78     }
    79   }
    80   return NULL;
    81 }
    83 //------------------------------StartOSRNode----------------------------------
    84 // The method start node for an on stack replacement adapter
    86 //------------------------------osr_domain-----------------------------
    87 const TypeTuple *StartOSRNode::osr_domain() {
    88   const Type **fields = TypeTuple::fields(2);
    89   fields[TypeFunc::Parms+0] = TypeRawPtr::BOTTOM;  // address of osr buffer
    91   return TypeTuple::make(TypeFunc::Parms+1, fields);
    92 }
    94 //=============================================================================
    95 const char * const ParmNode::names[TypeFunc::Parms+1] = {
    96   "Control", "I_O", "Memory", "FramePtr", "ReturnAdr", "Parms"
    97 };
    99 #ifndef PRODUCT
   100 void ParmNode::dump_spec(outputStream *st) const {
   101   if( _con < TypeFunc::Parms ) {
   102     st->print(names[_con]);
   103   } else {
   104     st->print("Parm%d: ",_con-TypeFunc::Parms);
   105     // Verbose and WizardMode dump bottom_type for all nodes
   106     if( !Verbose && !WizardMode )   bottom_type()->dump_on(st);
   107   }
   108 }
   109 #endif
   111 uint ParmNode::ideal_reg() const {
   112   switch( _con ) {
   113   case TypeFunc::Control  : // fall through
   114   case TypeFunc::I_O      : // fall through
   115   case TypeFunc::Memory   : return 0;
   116   case TypeFunc::FramePtr : // fall through
   117   case TypeFunc::ReturnAdr: return Op_RegP;
   118   default                 : assert( _con > TypeFunc::Parms, "" );
   119     // fall through
   120   case TypeFunc::Parms    : {
   121     // Type of argument being passed
   122     const Type *t = in(0)->as_Start()->_domain->field_at(_con);
   123     return Matcher::base2reg[t->base()];
   124   }
   125   }
   126   ShouldNotReachHere();
   127   return 0;
   128 }
   130 //=============================================================================
   131 ReturnNode::ReturnNode(uint edges, Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *retadr ) : Node(edges) {
   132   init_req(TypeFunc::Control,cntrl);
   133   init_req(TypeFunc::I_O,i_o);
   134   init_req(TypeFunc::Memory,memory);
   135   init_req(TypeFunc::FramePtr,frameptr);
   136   init_req(TypeFunc::ReturnAdr,retadr);
   137 }
   139 Node *ReturnNode::Ideal(PhaseGVN *phase, bool can_reshape){
   140   return remove_dead_region(phase, can_reshape) ? this : NULL;
   141 }
   143 const Type *ReturnNode::Value( PhaseTransform *phase ) const {
   144   return ( phase->type(in(TypeFunc::Control)) == Type::TOP)
   145     ? Type::TOP
   146     : Type::BOTTOM;
   147 }
   149 // Do we Match on this edge index or not?  No edges on return nodes
   150 uint ReturnNode::match_edge(uint idx) const {
   151   return 0;
   152 }
   155 #ifndef PRODUCT
   156 void ReturnNode::dump_req() const {
   157   // Dump the required inputs, enclosed in '(' and ')'
   158   uint i;                       // Exit value of loop
   159   for( i=0; i<req(); i++ ) {    // For all required inputs
   160     if( i == TypeFunc::Parms ) tty->print("returns");
   161     if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
   162     else tty->print("_ ");
   163   }
   164 }
   165 #endif
   167 //=============================================================================
   168 RethrowNode::RethrowNode(
   169   Node* cntrl,
   170   Node* i_o,
   171   Node* memory,
   172   Node* frameptr,
   173   Node* ret_adr,
   174   Node* exception
   175 ) : Node(TypeFunc::Parms + 1) {
   176   init_req(TypeFunc::Control  , cntrl    );
   177   init_req(TypeFunc::I_O      , i_o      );
   178   init_req(TypeFunc::Memory   , memory   );
   179   init_req(TypeFunc::FramePtr , frameptr );
   180   init_req(TypeFunc::ReturnAdr, ret_adr);
   181   init_req(TypeFunc::Parms    , exception);
   182 }
   184 Node *RethrowNode::Ideal(PhaseGVN *phase, bool can_reshape){
   185   return remove_dead_region(phase, can_reshape) ? this : NULL;
   186 }
   188 const Type *RethrowNode::Value( PhaseTransform *phase ) const {
   189   return (phase->type(in(TypeFunc::Control)) == Type::TOP)
   190     ? Type::TOP
   191     : Type::BOTTOM;
   192 }
   194 uint RethrowNode::match_edge(uint idx) const {
   195   return 0;
   196 }
   198 #ifndef PRODUCT
   199 void RethrowNode::dump_req() const {
   200   // Dump the required inputs, enclosed in '(' and ')'
   201   uint i;                       // Exit value of loop
   202   for( i=0; i<req(); i++ ) {    // For all required inputs
   203     if( i == TypeFunc::Parms ) tty->print("exception");
   204     if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
   205     else tty->print("_ ");
   206   }
   207 }
   208 #endif
   210 //=============================================================================
   211 // Do we Match on this edge index or not?  Match only target address & method
   212 uint TailCallNode::match_edge(uint idx) const {
   213   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
   214 }
   216 //=============================================================================
   217 // Do we Match on this edge index or not?  Match only target address & oop
   218 uint TailJumpNode::match_edge(uint idx) const {
   219   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
   220 }
   222 //=============================================================================
   223 JVMState::JVMState(ciMethod* method, JVMState* caller) {
   224   assert(method != NULL, "must be valid call site");
   225   _method = method;
   226   debug_only(_bci = -99);  // random garbage value
   227   debug_only(_map = (SafePointNode*)-1);
   228   _caller = caller;
   229   _depth  = 1 + (caller == NULL ? 0 : caller->depth());
   230   _locoff = TypeFunc::Parms;
   231   _stkoff = _locoff + _method->max_locals();
   232   _monoff = _stkoff + _method->max_stack();
   233   _scloff = _monoff;
   234   _endoff = _monoff;
   235   _sp = 0;
   236 }
   237 JVMState::JVMState(int stack_size) {
   238   _method = NULL;
   239   _bci = InvocationEntryBci;
   240   debug_only(_map = (SafePointNode*)-1);
   241   _caller = NULL;
   242   _depth  = 1;
   243   _locoff = TypeFunc::Parms;
   244   _stkoff = _locoff;
   245   _monoff = _stkoff + stack_size;
   246   _scloff = _monoff;
   247   _endoff = _monoff;
   248   _sp = 0;
   249 }
   251 //--------------------------------of_depth-------------------------------------
   252 JVMState* JVMState::of_depth(int d) const {
   253   const JVMState* jvmp = this;
   254   assert(0 < d && (uint)d <= depth(), "oob");
   255   for (int skip = depth() - d; skip > 0; skip--) {
   256     jvmp = jvmp->caller();
   257   }
   258   assert(jvmp->depth() == (uint)d, "found the right one");
   259   return (JVMState*)jvmp;
   260 }
   262 //-----------------------------same_calls_as-----------------------------------
   263 bool JVMState::same_calls_as(const JVMState* that) const {
   264   if (this == that)                    return true;
   265   if (this->depth() != that->depth())  return false;
   266   const JVMState* p = this;
   267   const JVMState* q = that;
   268   for (;;) {
   269     if (p->_method != q->_method)    return false;
   270     if (p->_method == NULL)          return true;   // bci is irrelevant
   271     if (p->_bci    != q->_bci)       return false;
   272     p = p->caller();
   273     q = q->caller();
   274     if (p == q)                      return true;
   275     assert(p != NULL && q != NULL, "depth check ensures we don't run off end");
   276   }
   277 }
   279 //------------------------------debug_start------------------------------------
   280 uint JVMState::debug_start()  const {
   281   debug_only(JVMState* jvmroot = of_depth(1));
   282   assert(jvmroot->locoff() <= this->locoff(), "youngest JVMState must be last");
   283   return of_depth(1)->locoff();
   284 }
   286 //-------------------------------debug_end-------------------------------------
   287 uint JVMState::debug_end() const {
   288   debug_only(JVMState* jvmroot = of_depth(1));
   289   assert(jvmroot->endoff() <= this->endoff(), "youngest JVMState must be last");
   290   return endoff();
   291 }
   293 //------------------------------debug_depth------------------------------------
   294 uint JVMState::debug_depth() const {
   295   uint total = 0;
   296   for (const JVMState* jvmp = this; jvmp != NULL; jvmp = jvmp->caller()) {
   297     total += jvmp->debug_size();
   298   }
   299   return total;
   300 }
   302 #ifndef PRODUCT
   304 //------------------------------format_helper----------------------------------
   305 // Given an allocation (a Chaitin object) and a Node decide if the Node carries
   306 // any defined value or not.  If it does, print out the register or constant.
   307 static void format_helper( PhaseRegAlloc *regalloc, outputStream* st, Node *n, const char *msg, uint i, GrowableArray<SafePointScalarObjectNode*> *scobjs ) {
   308   if (n == NULL) { st->print(" NULL"); return; }
   309   if (n->is_SafePointScalarObject()) {
   310     // Scalar replacement.
   311     SafePointScalarObjectNode* spobj = n->as_SafePointScalarObject();
   312     scobjs->append_if_missing(spobj);
   313     int sco_n = scobjs->find(spobj);
   314     assert(sco_n >= 0, "");
   315     st->print(" %s%d]=#ScObj" INT32_FORMAT, msg, i, sco_n);
   316     return;
   317   }
   318   if( OptoReg::is_valid(regalloc->get_reg_first(n))) { // Check for undefined
   319     char buf[50];
   320     regalloc->dump_register(n,buf);
   321     st->print(" %s%d]=%s",msg,i,buf);
   322   } else {                      // No register, but might be constant
   323     const Type *t = n->bottom_type();
   324     switch (t->base()) {
   325     case Type::Int:
   326       st->print(" %s%d]=#"INT32_FORMAT,msg,i,t->is_int()->get_con());
   327       break;
   328     case Type::AnyPtr:
   329       assert( t == TypePtr::NULL_PTR, "" );
   330       st->print(" %s%d]=#NULL",msg,i);
   331       break;
   332     case Type::AryPtr:
   333     case Type::KlassPtr:
   334     case Type::InstPtr:
   335       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,t->isa_oopptr()->const_oop());
   336       break;
   337     case Type::NarrowOop:
   338       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,t->make_ptr()->isa_oopptr()->const_oop());
   339       break;
   340     case Type::RawPtr:
   341       st->print(" %s%d]=#Raw" INTPTR_FORMAT,msg,i,t->is_rawptr());
   342       break;
   343     case Type::DoubleCon:
   344       st->print(" %s%d]=#%fD",msg,i,t->is_double_constant()->_d);
   345       break;
   346     case Type::FloatCon:
   347       st->print(" %s%d]=#%fF",msg,i,t->is_float_constant()->_f);
   348       break;
   349     case Type::Long:
   350       st->print(" %s%d]=#"INT64_FORMAT,msg,i,t->is_long()->get_con());
   351       break;
   352     case Type::Half:
   353     case Type::Top:
   354       st->print(" %s%d]=_",msg,i);
   355       break;
   356     default: ShouldNotReachHere();
   357     }
   358   }
   359 }
   361 //------------------------------format-----------------------------------------
   362 void JVMState::format(PhaseRegAlloc *regalloc, const Node *n, outputStream* st) const {
   363   st->print("        #");
   364   if( _method ) {
   365     _method->print_short_name(st);
   366     st->print(" @ bci:%d ",_bci);
   367   } else {
   368     st->print_cr(" runtime stub ");
   369     return;
   370   }
   371   if (n->is_MachSafePoint()) {
   372     GrowableArray<SafePointScalarObjectNode*> scobjs;
   373     MachSafePointNode *mcall = n->as_MachSafePoint();
   374     uint i;
   375     // Print locals
   376     for( i = 0; i < (uint)loc_size(); i++ )
   377       format_helper( regalloc, st, mcall->local(this, i), "L[", i, &scobjs );
   378     // Print stack
   379     for (i = 0; i < (uint)stk_size(); i++) {
   380       if ((uint)(_stkoff + i) >= mcall->len())
   381         st->print(" oob ");
   382       else
   383        format_helper( regalloc, st, mcall->stack(this, i), "STK[", i, &scobjs );
   384     }
   385     for (i = 0; (int)i < nof_monitors(); i++) {
   386       Node *box = mcall->monitor_box(this, i);
   387       Node *obj = mcall->monitor_obj(this, i);
   388       if ( OptoReg::is_valid(regalloc->get_reg_first(box)) ) {
   389         while( !box->is_BoxLock() )  box = box->in(1);
   390         format_helper( regalloc, st, box, "MON-BOX[", i, &scobjs );
   391       } else {
   392         OptoReg::Name box_reg = BoxLockNode::stack_slot(box);
   393         st->print(" MON-BOX%d=%s+%d",
   394                    i,
   395                    OptoReg::regname(OptoReg::c_frame_pointer),
   396                    regalloc->reg2offset(box_reg));
   397       }
   398       const char* obj_msg = "MON-OBJ[";
   399       if (EliminateLocks) {
   400         while( !box->is_BoxLock() )  box = box->in(1);
   401         if (box->as_BoxLock()->is_eliminated())
   402           obj_msg = "MON-OBJ(LOCK ELIMINATED)[";
   403       }
   404       format_helper( regalloc, st, obj, obj_msg, i, &scobjs );
   405     }
   407     for (i = 0; i < (uint)scobjs.length(); i++) {
   408       // Scalar replaced objects.
   409       st->print_cr("");
   410       st->print("        # ScObj" INT32_FORMAT " ", i);
   411       SafePointScalarObjectNode* spobj = scobjs.at(i);
   412       ciKlass* cik = spobj->bottom_type()->is_oopptr()->klass();
   413       assert(cik->is_instance_klass() ||
   414              cik->is_array_klass(), "Not supported allocation.");
   415       ciInstanceKlass *iklass = NULL;
   416       if (cik->is_instance_klass()) {
   417         cik->print_name_on(st);
   418         iklass = cik->as_instance_klass();
   419       } else if (cik->is_type_array_klass()) {
   420         cik->as_array_klass()->base_element_type()->print_name_on(st);
   421         st->print("[%d]=", spobj->n_fields());
   422       } else if (cik->is_obj_array_klass()) {
   423         ciType* cie = cik->as_array_klass()->base_element_type();
   424         int ndim = 1;
   425         while (cie->is_obj_array_klass()) {
   426           ndim += 1;
   427           cie = cie->as_array_klass()->base_element_type();
   428         }
   429         cie->print_name_on(st);
   430         while (ndim-- > 0) {
   431           st->print("[]");
   432         }
   433         st->print("[%d]=", spobj->n_fields());
   434       }
   435       st->print("{");
   436       uint nf = spobj->n_fields();
   437       if (nf > 0) {
   438         uint first_ind = spobj->first_index();
   439         Node* fld_node = mcall->in(first_ind);
   440         ciField* cifield;
   441         if (iklass != NULL) {
   442           st->print(" [");
   443           cifield = iklass->nonstatic_field_at(0);
   444           cifield->print_name_on(st);
   445           format_helper( regalloc, st, fld_node, ":", 0, &scobjs );
   446         } else {
   447           format_helper( regalloc, st, fld_node, "[", 0, &scobjs );
   448         }
   449         for (uint j = 1; j < nf; j++) {
   450           fld_node = mcall->in(first_ind+j);
   451           if (iklass != NULL) {
   452             st->print(", [");
   453             cifield = iklass->nonstatic_field_at(j);
   454             cifield->print_name_on(st);
   455             format_helper( regalloc, st, fld_node, ":", j, &scobjs );
   456           } else {
   457             format_helper( regalloc, st, fld_node, ", [", j, &scobjs );
   458           }
   459         }
   460       }
   461       st->print(" }");
   462     }
   463   }
   464   st->print_cr("");
   465   if (caller() != NULL)  caller()->format(regalloc, n, st);
   466 }
   469 void JVMState::dump_spec(outputStream *st) const {
   470   if (_method != NULL) {
   471     bool printed = false;
   472     if (!Verbose) {
   473       // The JVMS dumps make really, really long lines.
   474       // Take out the most boring parts, which are the package prefixes.
   475       char buf[500];
   476       stringStream namest(buf, sizeof(buf));
   477       _method->print_short_name(&namest);
   478       if (namest.count() < sizeof(buf)) {
   479         const char* name = namest.base();
   480         if (name[0] == ' ')  ++name;
   481         const char* endcn = strchr(name, ':');  // end of class name
   482         if (endcn == NULL)  endcn = strchr(name, '(');
   483         if (endcn == NULL)  endcn = name + strlen(name);
   484         while (endcn > name && endcn[-1] != '.' && endcn[-1] != '/')
   485           --endcn;
   486         st->print(" %s", endcn);
   487         printed = true;
   488       }
   489     }
   490     if (!printed)
   491       _method->print_short_name(st);
   492     st->print(" @ bci:%d",_bci);
   493   } else {
   494     st->print(" runtime stub");
   495   }
   496   if (caller() != NULL)  caller()->dump_spec(st);
   497 }
   500 void JVMState::dump_on(outputStream* st) const {
   501   if (_map && !((uintptr_t)_map & 1)) {
   502     if (_map->len() > _map->req()) {  // _map->has_exceptions()
   503       Node* ex = _map->in(_map->req());  // _map->next_exception()
   504       // skip the first one; it's already being printed
   505       while (ex != NULL && ex->len() > ex->req()) {
   506         ex = ex->in(ex->req());  // ex->next_exception()
   507         ex->dump(1);
   508       }
   509     }
   510     _map->dump(2);
   511   }
   512   st->print("JVMS depth=%d loc=%d stk=%d mon=%d scalar=%d end=%d mondepth=%d sp=%d bci=%d method=",
   513              depth(), locoff(), stkoff(), monoff(), scloff(), endoff(), monitor_depth(), sp(), bci());
   514   if (_method == NULL) {
   515     st->print_cr("(none)");
   516   } else {
   517     _method->print_name(st);
   518     st->cr();
   519     if (bci() >= 0 && bci() < _method->code_size()) {
   520       st->print("    bc: ");
   521       _method->print_codes_on(bci(), bci()+1, st);
   522     }
   523   }
   524   if (caller() != NULL) {
   525     caller()->dump_on(st);
   526   }
   527 }
   529 // Extra way to dump a jvms from the debugger,
   530 // to avoid a bug with C++ member function calls.
   531 void dump_jvms(JVMState* jvms) {
   532   jvms->dump();
   533 }
   534 #endif
   536 //--------------------------clone_shallow--------------------------------------
   537 JVMState* JVMState::clone_shallow(Compile* C) const {
   538   JVMState* n = has_method() ? new (C) JVMState(_method, _caller) : new (C) JVMState(0);
   539   n->set_bci(_bci);
   540   n->set_locoff(_locoff);
   541   n->set_stkoff(_stkoff);
   542   n->set_monoff(_monoff);
   543   n->set_scloff(_scloff);
   544   n->set_endoff(_endoff);
   545   n->set_sp(_sp);
   546   n->set_map(_map);
   547   return n;
   548 }
   550 //---------------------------clone_deep----------------------------------------
   551 JVMState* JVMState::clone_deep(Compile* C) const {
   552   JVMState* n = clone_shallow(C);
   553   for (JVMState* p = n; p->_caller != NULL; p = p->_caller) {
   554     p->_caller = p->_caller->clone_shallow(C);
   555   }
   556   assert(n->depth() == depth(), "sanity");
   557   assert(n->debug_depth() == debug_depth(), "sanity");
   558   return n;
   559 }
   561 //=============================================================================
   562 uint CallNode::cmp( const Node &n ) const
   563 { return _tf == ((CallNode&)n)._tf && _jvms == ((CallNode&)n)._jvms; }
   564 #ifndef PRODUCT
   565 void CallNode::dump_req() const {
   566   // Dump the required inputs, enclosed in '(' and ')'
   567   uint i;                       // Exit value of loop
   568   for( i=0; i<req(); i++ ) {    // For all required inputs
   569     if( i == TypeFunc::Parms ) tty->print("(");
   570     if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
   571     else tty->print("_ ");
   572   }
   573   tty->print(")");
   574 }
   576 void CallNode::dump_spec(outputStream *st) const {
   577   st->print(" ");
   578   tf()->dump_on(st);
   579   if (_cnt != COUNT_UNKNOWN)  st->print(" C=%f",_cnt);
   580   if (jvms() != NULL)  jvms()->dump_spec(st);
   581 }
   582 #endif
   584 const Type *CallNode::bottom_type() const { return tf()->range(); }
   585 const Type *CallNode::Value(PhaseTransform *phase) const {
   586   if (phase->type(in(0)) == Type::TOP)  return Type::TOP;
   587   return tf()->range();
   588 }
   590 //------------------------------calling_convention-----------------------------
   591 void CallNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
   592   // Use the standard compiler calling convention
   593   Matcher::calling_convention( sig_bt, parm_regs, argcnt, true );
   594 }
   597 //------------------------------match------------------------------------------
   598 // Construct projections for control, I/O, memory-fields, ..., and
   599 // return result(s) along with their RegMask info
   600 Node *CallNode::match( const ProjNode *proj, const Matcher *match ) {
   601   switch (proj->_con) {
   602   case TypeFunc::Control:
   603   case TypeFunc::I_O:
   604   case TypeFunc::Memory:
   605     return new (match->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
   607   case TypeFunc::Parms+1:       // For LONG & DOUBLE returns
   608     assert(tf()->_range->field_at(TypeFunc::Parms+1) == Type::HALF, "");
   609     // 2nd half of doubles and longs
   610     return new (match->C, 1) MachProjNode(this,proj->_con, RegMask::Empty, (uint)OptoReg::Bad);
   612   case TypeFunc::Parms: {       // Normal returns
   613     uint ideal_reg = Matcher::base2reg[tf()->range()->field_at(TypeFunc::Parms)->base()];
   614     OptoRegPair regs = is_CallRuntime()
   615       ? match->c_return_value(ideal_reg,true)  // Calls into C runtime
   616       : match->  return_value(ideal_reg,true); // Calls into compiled Java code
   617     RegMask rm = RegMask(regs.first());
   618     if( OptoReg::is_valid(regs.second()) )
   619       rm.Insert( regs.second() );
   620     return new (match->C, 1) MachProjNode(this,proj->_con,rm,ideal_reg);
   621   }
   623   case TypeFunc::ReturnAdr:
   624   case TypeFunc::FramePtr:
   625   default:
   626     ShouldNotReachHere();
   627   }
   628   return NULL;
   629 }
   631 // Do we Match on this edge index or not?  Match no edges
   632 uint CallNode::match_edge(uint idx) const {
   633   return 0;
   634 }
   636 //
   637 // Determine whether the call could modify the field of the specified
   638 // instance at the specified offset.
   639 //
   640 bool CallNode::may_modify(const TypePtr *addr_t, PhaseTransform *phase) {
   641   const TypeOopPtr *adrInst_t  = addr_t->isa_oopptr();
   643   // If not an OopPtr or not an instance type, assume the worst.
   644   // Note: currently this method is called only for instance types.
   645   if (adrInst_t == NULL || !adrInst_t->is_known_instance()) {
   646     return true;
   647   }
   648   // The instance_id is set only for scalar-replaceable allocations which
   649   // are not passed as arguments according to Escape Analysis.
   650   return false;
   651 }
   653 // Does this call have a direct reference to n other than debug information?
   654 bool CallNode::has_non_debug_use(Node *n) {
   655   const TypeTuple * d = tf()->domain();
   656   for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
   657     Node *arg = in(i);
   658     if (arg == n) {
   659       return true;
   660     }
   661   }
   662   return false;
   663 }
   665 // Returns the unique CheckCastPP of a call
   666 // or 'this' if there are several CheckCastPP
   667 // or returns NULL if there is no one.
   668 Node *CallNode::result_cast() {
   669   Node *cast = NULL;
   671   Node *p = proj_out(TypeFunc::Parms);
   672   if (p == NULL)
   673     return NULL;
   675   for (DUIterator_Fast imax, i = p->fast_outs(imax); i < imax; i++) {
   676     Node *use = p->fast_out(i);
   677     if (use->is_CheckCastPP()) {
   678       if (cast != NULL) {
   679         return this;  // more than 1 CheckCastPP
   680       }
   681       cast = use;
   682     }
   683   }
   684   return cast;
   685 }
   688 //=============================================================================
   689 uint CallJavaNode::size_of() const { return sizeof(*this); }
   690 uint CallJavaNode::cmp( const Node &n ) const {
   691   CallJavaNode &call = (CallJavaNode&)n;
   692   return CallNode::cmp(call) && _method == call._method;
   693 }
   694 #ifndef PRODUCT
   695 void CallJavaNode::dump_spec(outputStream *st) const {
   696   if( _method ) _method->print_short_name(st);
   697   CallNode::dump_spec(st);
   698 }
   699 #endif
   701 //=============================================================================
   702 uint CallStaticJavaNode::size_of() const { return sizeof(*this); }
   703 uint CallStaticJavaNode::cmp( const Node &n ) const {
   704   CallStaticJavaNode &call = (CallStaticJavaNode&)n;
   705   return CallJavaNode::cmp(call);
   706 }
   708 //----------------------------uncommon_trap_request----------------------------
   709 // If this is an uncommon trap, return the request code, else zero.
   710 int CallStaticJavaNode::uncommon_trap_request() const {
   711   if (_name != NULL && !strcmp(_name, "uncommon_trap")) {
   712     return extract_uncommon_trap_request(this);
   713   }
   714   return 0;
   715 }
   716 int CallStaticJavaNode::extract_uncommon_trap_request(const Node* call) {
   717 #ifndef PRODUCT
   718   if (!(call->req() > TypeFunc::Parms &&
   719         call->in(TypeFunc::Parms) != NULL &&
   720         call->in(TypeFunc::Parms)->is_Con())) {
   721     assert(_in_dump_cnt != 0, "OK if dumping");
   722     tty->print("[bad uncommon trap]");
   723     return 0;
   724   }
   725 #endif
   726   return call->in(TypeFunc::Parms)->bottom_type()->is_int()->get_con();
   727 }
   729 #ifndef PRODUCT
   730 void CallStaticJavaNode::dump_spec(outputStream *st) const {
   731   st->print("# Static ");
   732   if (_name != NULL) {
   733     st->print("%s", _name);
   734     int trap_req = uncommon_trap_request();
   735     if (trap_req != 0) {
   736       char buf[100];
   737       st->print("(%s)",
   738                  Deoptimization::format_trap_request(buf, sizeof(buf),
   739                                                      trap_req));
   740     }
   741     st->print(" ");
   742   }
   743   CallJavaNode::dump_spec(st);
   744 }
   745 #endif
   747 //=============================================================================
   748 uint CallDynamicJavaNode::size_of() const { return sizeof(*this); }
   749 uint CallDynamicJavaNode::cmp( const Node &n ) const {
   750   CallDynamicJavaNode &call = (CallDynamicJavaNode&)n;
   751   return CallJavaNode::cmp(call);
   752 }
   753 #ifndef PRODUCT
   754 void CallDynamicJavaNode::dump_spec(outputStream *st) const {
   755   st->print("# Dynamic ");
   756   CallJavaNode::dump_spec(st);
   757 }
   758 #endif
   760 //=============================================================================
   761 uint CallRuntimeNode::size_of() const { return sizeof(*this); }
   762 uint CallRuntimeNode::cmp( const Node &n ) const {
   763   CallRuntimeNode &call = (CallRuntimeNode&)n;
   764   return CallNode::cmp(call) && !strcmp(_name,call._name);
   765 }
   766 #ifndef PRODUCT
   767 void CallRuntimeNode::dump_spec(outputStream *st) const {
   768   st->print("# ");
   769   st->print(_name);
   770   CallNode::dump_spec(st);
   771 }
   772 #endif
   774 //------------------------------calling_convention-----------------------------
   775 void CallRuntimeNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
   776   Matcher::c_calling_convention( sig_bt, parm_regs, argcnt );
   777 }
   779 //=============================================================================
   780 //------------------------------calling_convention-----------------------------
   783 //=============================================================================
   784 #ifndef PRODUCT
   785 void CallLeafNode::dump_spec(outputStream *st) const {
   786   st->print("# ");
   787   st->print(_name);
   788   CallNode::dump_spec(st);
   789 }
   790 #endif
   792 //=============================================================================
   794 void SafePointNode::set_local(JVMState* jvms, uint idx, Node *c) {
   795   assert(verify_jvms(jvms), "jvms must match");
   796   int loc = jvms->locoff() + idx;
   797   if (in(loc)->is_top() && idx > 0 && !c->is_top() ) {
   798     // If current local idx is top then local idx - 1 could
   799     // be a long/double that needs to be killed since top could
   800     // represent the 2nd half ofthe long/double.
   801     uint ideal = in(loc -1)->ideal_reg();
   802     if (ideal == Op_RegD || ideal == Op_RegL) {
   803       // set other (low index) half to top
   804       set_req(loc - 1, in(loc));
   805     }
   806   }
   807   set_req(loc, c);
   808 }
   810 uint SafePointNode::size_of() const { return sizeof(*this); }
   811 uint SafePointNode::cmp( const Node &n ) const {
   812   return (&n == this);          // Always fail except on self
   813 }
   815 //-------------------------set_next_exception----------------------------------
   816 void SafePointNode::set_next_exception(SafePointNode* n) {
   817   assert(n == NULL || n->Opcode() == Op_SafePoint, "correct value for next_exception");
   818   if (len() == req()) {
   819     if (n != NULL)  add_prec(n);
   820   } else {
   821     set_prec(req(), n);
   822   }
   823 }
   826 //----------------------------next_exception-----------------------------------
   827 SafePointNode* SafePointNode::next_exception() const {
   828   if (len() == req()) {
   829     return NULL;
   830   } else {
   831     Node* n = in(req());
   832     assert(n == NULL || n->Opcode() == Op_SafePoint, "no other uses of prec edges");
   833     return (SafePointNode*) n;
   834   }
   835 }
   838 //------------------------------Ideal------------------------------------------
   839 // Skip over any collapsed Regions
   840 Node *SafePointNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   841   return remove_dead_region(phase, can_reshape) ? this : NULL;
   842 }
   844 //------------------------------Identity---------------------------------------
   845 // Remove obviously duplicate safepoints
   846 Node *SafePointNode::Identity( PhaseTransform *phase ) {
   848   // If you have back to back safepoints, remove one
   849   if( in(TypeFunc::Control)->is_SafePoint() )
   850     return in(TypeFunc::Control);
   852   if( in(0)->is_Proj() ) {
   853     Node *n0 = in(0)->in(0);
   854     // Check if he is a call projection (except Leaf Call)
   855     if( n0->is_Catch() ) {
   856       n0 = n0->in(0)->in(0);
   857       assert( n0->is_Call(), "expect a call here" );
   858     }
   859     if( n0->is_Call() && n0->as_Call()->guaranteed_safepoint() ) {
   860       // Useless Safepoint, so remove it
   861       return in(TypeFunc::Control);
   862     }
   863   }
   865   return this;
   866 }
   868 //------------------------------Value------------------------------------------
   869 const Type *SafePointNode::Value( PhaseTransform *phase ) const {
   870   if( phase->type(in(0)) == Type::TOP ) return Type::TOP;
   871   if( phase->eqv( in(0), this ) ) return Type::TOP; // Dead infinite loop
   872   return Type::CONTROL;
   873 }
   875 #ifndef PRODUCT
   876 void SafePointNode::dump_spec(outputStream *st) const {
   877   st->print(" SafePoint ");
   878 }
   879 #endif
   881 const RegMask &SafePointNode::in_RegMask(uint idx) const {
   882   if( idx < TypeFunc::Parms ) return RegMask::Empty;
   883   // Values outside the domain represent debug info
   884   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
   885 }
   886 const RegMask &SafePointNode::out_RegMask() const {
   887   return RegMask::Empty;
   888 }
   891 void SafePointNode::grow_stack(JVMState* jvms, uint grow_by) {
   892   assert((int)grow_by > 0, "sanity");
   893   int monoff = jvms->monoff();
   894   int scloff = jvms->scloff();
   895   int endoff = jvms->endoff();
   896   assert(endoff == (int)req(), "no other states or debug info after me");
   897   Node* top = Compile::current()->top();
   898   for (uint i = 0; i < grow_by; i++) {
   899     ins_req(monoff, top);
   900   }
   901   jvms->set_monoff(monoff + grow_by);
   902   jvms->set_scloff(scloff + grow_by);
   903   jvms->set_endoff(endoff + grow_by);
   904 }
   906 void SafePointNode::push_monitor(const FastLockNode *lock) {
   907   // Add a LockNode, which points to both the original BoxLockNode (the
   908   // stack space for the monitor) and the Object being locked.
   909   const int MonitorEdges = 2;
   910   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
   911   assert(req() == jvms()->endoff(), "correct sizing");
   912   int nextmon = jvms()->scloff();
   913   if (GenerateSynchronizationCode) {
   914     add_req(lock->box_node());
   915     add_req(lock->obj_node());
   916   } else {
   917     Node* top = Compile::current()->top();
   918     add_req(top);
   919     add_req(top);
   920   }
   921   jvms()->set_scloff(nextmon+MonitorEdges);
   922   jvms()->set_endoff(req());
   923 }
   925 void SafePointNode::pop_monitor() {
   926   // Delete last monitor from debug info
   927   debug_only(int num_before_pop = jvms()->nof_monitors());
   928   const int MonitorEdges = (1<<JVMState::logMonitorEdges);
   929   int scloff = jvms()->scloff();
   930   int endoff = jvms()->endoff();
   931   int new_scloff = scloff - MonitorEdges;
   932   int new_endoff = endoff - MonitorEdges;
   933   jvms()->set_scloff(new_scloff);
   934   jvms()->set_endoff(new_endoff);
   935   while (scloff > new_scloff)  del_req(--scloff);
   936   assert(jvms()->nof_monitors() == num_before_pop-1, "");
   937 }
   939 Node *SafePointNode::peek_monitor_box() const {
   940   int mon = jvms()->nof_monitors() - 1;
   941   assert(mon >= 0, "most have a monitor");
   942   return monitor_box(jvms(), mon);
   943 }
   945 Node *SafePointNode::peek_monitor_obj() const {
   946   int mon = jvms()->nof_monitors() - 1;
   947   assert(mon >= 0, "most have a monitor");
   948   return monitor_obj(jvms(), mon);
   949 }
   951 // Do we Match on this edge index or not?  Match no edges
   952 uint SafePointNode::match_edge(uint idx) const {
   953   if( !needs_polling_address_input() )
   954     return 0;
   956   return (TypeFunc::Parms == idx);
   957 }
   959 //==============  SafePointScalarObjectNode  ==============
   961 SafePointScalarObjectNode::SafePointScalarObjectNode(const TypeOopPtr* tp,
   962 #ifdef ASSERT
   963                                                      AllocateNode* alloc,
   964 #endif
   965                                                      uint first_index,
   966                                                      uint n_fields) :
   967   TypeNode(tp, 1), // 1 control input -- seems required.  Get from root.
   968 #ifdef ASSERT
   969   _alloc(alloc),
   970 #endif
   971   _first_index(first_index),
   972   _n_fields(n_fields)
   973 {
   974   init_class_id(Class_SafePointScalarObject);
   975 }
   977 bool SafePointScalarObjectNode::pinned() const { return true; }
   979 uint SafePointScalarObjectNode::ideal_reg() const {
   980   return 0; // No matching to machine instruction
   981 }
   983 const RegMask &SafePointScalarObjectNode::in_RegMask(uint idx) const {
   984   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
   985 }
   987 const RegMask &SafePointScalarObjectNode::out_RegMask() const {
   988   return RegMask::Empty;
   989 }
   991 uint SafePointScalarObjectNode::match_edge(uint idx) const {
   992   return 0;
   993 }
   995 SafePointScalarObjectNode*
   996 SafePointScalarObjectNode::clone(int jvms_adj, Dict* sosn_map) const {
   997   void* cached = (*sosn_map)[(void*)this];
   998   if (cached != NULL) {
   999     return (SafePointScalarObjectNode*)cached;
  1001   Compile* C = Compile::current();
  1002   SafePointScalarObjectNode* res = (SafePointScalarObjectNode*)Node::clone();
  1003   res->_first_index += jvms_adj;
  1004   sosn_map->Insert((void*)this, (void*)res);
  1005   return res;
  1009 #ifndef PRODUCT
  1010 void SafePointScalarObjectNode::dump_spec(outputStream *st) const {
  1011   st->print(" # fields@[%d..%d]", first_index(),
  1012              first_index() + n_fields() - 1);
  1015 #endif
  1017 //=============================================================================
  1018 uint AllocateNode::size_of() const { return sizeof(*this); }
  1020 AllocateNode::AllocateNode(Compile* C, const TypeFunc *atype,
  1021                            Node *ctrl, Node *mem, Node *abio,
  1022                            Node *size, Node *klass_node, Node *initial_test)
  1023   : CallNode(atype, NULL, TypeRawPtr::BOTTOM)
  1025   init_class_id(Class_Allocate);
  1026   init_flags(Flag_is_macro);
  1027   _is_scalar_replaceable = false;
  1028   Node *topnode = C->top();
  1030   init_req( TypeFunc::Control  , ctrl );
  1031   init_req( TypeFunc::I_O      , abio );
  1032   init_req( TypeFunc::Memory   , mem );
  1033   init_req( TypeFunc::ReturnAdr, topnode );
  1034   init_req( TypeFunc::FramePtr , topnode );
  1035   init_req( AllocSize          , size);
  1036   init_req( KlassNode          , klass_node);
  1037   init_req( InitialTest        , initial_test);
  1038   init_req( ALength            , topnode);
  1039   C->add_macro_node(this);
  1042 //=============================================================================
  1043 uint AllocateArrayNode::size_of() const { return sizeof(*this); }
  1045 // Retrieve the length from the AllocateArrayNode. Narrow the type with a
  1046 // CastII, if appropriate.  If we are not allowed to create new nodes, and
  1047 // a CastII is appropriate, return NULL.
  1048 Node *AllocateArrayNode::make_ideal_length(const TypeOopPtr* oop_type, PhaseTransform *phase, bool allow_new_nodes) {
  1049   Node *length = in(AllocateNode::ALength);
  1050   assert(length != NULL, "length is not null");
  1052   const TypeInt* length_type = phase->find_int_type(length);
  1053   const TypeAryPtr* ary_type = oop_type->isa_aryptr();
  1055   if (ary_type != NULL && length_type != NULL) {
  1056     const TypeInt* narrow_length_type = ary_type->narrow_size_type(length_type);
  1057     if (narrow_length_type != length_type) {
  1058       // Assert one of:
  1059       //   - the narrow_length is 0
  1060       //   - the narrow_length is not wider than length
  1061       assert(narrow_length_type == TypeInt::ZERO ||
  1062              (narrow_length_type->_hi <= length_type->_hi &&
  1063               narrow_length_type->_lo >= length_type->_lo),
  1064              "narrow type must be narrower than length type");
  1066       // Return NULL if new nodes are not allowed
  1067       if (!allow_new_nodes) return NULL;
  1068       // Create a cast which is control dependent on the initialization to
  1069       // propagate the fact that the array length must be positive.
  1070       length = new (phase->C, 2) CastIINode(length, narrow_length_type);
  1071       length->set_req(0, initialization()->proj_out(0));
  1075   return length;
  1078 //=============================================================================
  1079 uint LockNode::size_of() const { return sizeof(*this); }
  1081 // Redundant lock elimination
  1082 //
  1083 // There are various patterns of locking where we release and
  1084 // immediately reacquire a lock in a piece of code where no operations
  1085 // occur in between that would be observable.  In those cases we can
  1086 // skip releasing and reacquiring the lock without violating any
  1087 // fairness requirements.  Doing this around a loop could cause a lock
  1088 // to be held for a very long time so we concentrate on non-looping
  1089 // control flow.  We also require that the operations are fully
  1090 // redundant meaning that we don't introduce new lock operations on
  1091 // some paths so to be able to eliminate it on others ala PRE.  This
  1092 // would probably require some more extensive graph manipulation to
  1093 // guarantee that the memory edges were all handled correctly.
  1094 //
  1095 // Assuming p is a simple predicate which can't trap in any way and s
  1096 // is a synchronized method consider this code:
  1097 //
  1098 //   s();
  1099 //   if (p)
  1100 //     s();
  1101 //   else
  1102 //     s();
  1103 //   s();
  1104 //
  1105 // 1. The unlocks of the first call to s can be eliminated if the
  1106 // locks inside the then and else branches are eliminated.
  1107 //
  1108 // 2. The unlocks of the then and else branches can be eliminated if
  1109 // the lock of the final call to s is eliminated.
  1110 //
  1111 // Either of these cases subsumes the simple case of sequential control flow
  1112 //
  1113 // Addtionally we can eliminate versions without the else case:
  1114 //
  1115 //   s();
  1116 //   if (p)
  1117 //     s();
  1118 //   s();
  1119 //
  1120 // 3. In this case we eliminate the unlock of the first s, the lock
  1121 // and unlock in the then case and the lock in the final s.
  1122 //
  1123 // Note also that in all these cases the then/else pieces don't have
  1124 // to be trivial as long as they begin and end with synchronization
  1125 // operations.
  1126 //
  1127 //   s();
  1128 //   if (p)
  1129 //     s();
  1130 //     f();
  1131 //     s();
  1132 //   s();
  1133 //
  1134 // The code will work properly for this case, leaving in the unlock
  1135 // before the call to f and the relock after it.
  1136 //
  1137 // A potentially interesting case which isn't handled here is when the
  1138 // locking is partially redundant.
  1139 //
  1140 //   s();
  1141 //   if (p)
  1142 //     s();
  1143 //
  1144 // This could be eliminated putting unlocking on the else case and
  1145 // eliminating the first unlock and the lock in the then side.
  1146 // Alternatively the unlock could be moved out of the then side so it
  1147 // was after the merge and the first unlock and second lock
  1148 // eliminated.  This might require less manipulation of the memory
  1149 // state to get correct.
  1150 //
  1151 // Additionally we might allow work between a unlock and lock before
  1152 // giving up eliminating the locks.  The current code disallows any
  1153 // conditional control flow between these operations.  A formulation
  1154 // similar to partial redundancy elimination computing the
  1155 // availability of unlocking and the anticipatability of locking at a
  1156 // program point would allow detection of fully redundant locking with
  1157 // some amount of work in between.  I'm not sure how often I really
  1158 // think that would occur though.  Most of the cases I've seen
  1159 // indicate it's likely non-trivial work would occur in between.
  1160 // There may be other more complicated constructs where we could
  1161 // eliminate locking but I haven't seen any others appear as hot or
  1162 // interesting.
  1163 //
  1164 // Locking and unlocking have a canonical form in ideal that looks
  1165 // roughly like this:
  1166 //
  1167 //              <obj>
  1168 //                | \\------+
  1169 //                |  \       \
  1170 //                | BoxLock   \
  1171 //                |  |   |     \
  1172 //                |  |    \     \
  1173 //                |  |   FastLock
  1174 //                |  |   /
  1175 //                |  |  /
  1176 //                |  |  |
  1177 //
  1178 //               Lock
  1179 //                |
  1180 //            Proj #0
  1181 //                |
  1182 //            MembarAcquire
  1183 //                |
  1184 //            Proj #0
  1185 //
  1186 //            MembarRelease
  1187 //                |
  1188 //            Proj #0
  1189 //                |
  1190 //              Unlock
  1191 //                |
  1192 //            Proj #0
  1193 //
  1194 //
  1195 // This code proceeds by processing Lock nodes during PhaseIterGVN
  1196 // and searching back through its control for the proper code
  1197 // patterns.  Once it finds a set of lock and unlock operations to
  1198 // eliminate they are marked as eliminatable which causes the
  1199 // expansion of the Lock and Unlock macro nodes to make the operation a NOP
  1200 //
  1201 //=============================================================================
  1203 //
  1204 // Utility function to skip over uninteresting control nodes.  Nodes skipped are:
  1205 //   - copy regions.  (These may not have been optimized away yet.)
  1206 //   - eliminated locking nodes
  1207 //
  1208 static Node *next_control(Node *ctrl) {
  1209   if (ctrl == NULL)
  1210     return NULL;
  1211   while (1) {
  1212     if (ctrl->is_Region()) {
  1213       RegionNode *r = ctrl->as_Region();
  1214       Node *n = r->is_copy();
  1215       if (n == NULL)
  1216         break;  // hit a region, return it
  1217       else
  1218         ctrl = n;
  1219     } else if (ctrl->is_Proj()) {
  1220       Node *in0 = ctrl->in(0);
  1221       if (in0->is_AbstractLock() && in0->as_AbstractLock()->is_eliminated()) {
  1222         ctrl = in0->in(0);
  1223       } else {
  1224         break;
  1226     } else {
  1227       break; // found an interesting control
  1230   return ctrl;
  1232 //
  1233 // Given a control, see if it's the control projection of an Unlock which
  1234 // operating on the same object as lock.
  1235 //
  1236 bool AbstractLockNode::find_matching_unlock(const Node* ctrl, LockNode* lock,
  1237                                             GrowableArray<AbstractLockNode*> &lock_ops) {
  1238   ProjNode *ctrl_proj = (ctrl->is_Proj()) ? ctrl->as_Proj() : NULL;
  1239   if (ctrl_proj != NULL && ctrl_proj->_con == TypeFunc::Control) {
  1240     Node *n = ctrl_proj->in(0);
  1241     if (n != NULL && n->is_Unlock()) {
  1242       UnlockNode *unlock = n->as_Unlock();
  1243       if ((lock->obj_node() == unlock->obj_node()) &&
  1244           (lock->box_node() == unlock->box_node()) && !unlock->is_eliminated()) {
  1245         lock_ops.append(unlock);
  1246         return true;
  1250   return false;
  1253 //
  1254 // Find the lock matching an unlock.  Returns null if a safepoint
  1255 // or complicated control is encountered first.
  1256 LockNode *AbstractLockNode::find_matching_lock(UnlockNode* unlock) {
  1257   LockNode *lock_result = NULL;
  1258   // find the matching lock, or an intervening safepoint
  1259   Node *ctrl = next_control(unlock->in(0));
  1260   while (1) {
  1261     assert(ctrl != NULL, "invalid control graph");
  1262     assert(!ctrl->is_Start(), "missing lock for unlock");
  1263     if (ctrl->is_top()) break;  // dead control path
  1264     if (ctrl->is_Proj()) ctrl = ctrl->in(0);
  1265     if (ctrl->is_SafePoint()) {
  1266         break;  // found a safepoint (may be the lock we are searching for)
  1267     } else if (ctrl->is_Region()) {
  1268       // Check for a simple diamond pattern.  Punt on anything more complicated
  1269       if (ctrl->req() == 3 && ctrl->in(1) != NULL && ctrl->in(2) != NULL) {
  1270         Node *in1 = next_control(ctrl->in(1));
  1271         Node *in2 = next_control(ctrl->in(2));
  1272         if (((in1->is_IfTrue() && in2->is_IfFalse()) ||
  1273              (in2->is_IfTrue() && in1->is_IfFalse())) && (in1->in(0) == in2->in(0))) {
  1274           ctrl = next_control(in1->in(0)->in(0));
  1275         } else {
  1276           break;
  1278       } else {
  1279         break;
  1281     } else {
  1282       ctrl = next_control(ctrl->in(0));  // keep searching
  1285   if (ctrl->is_Lock()) {
  1286     LockNode *lock = ctrl->as_Lock();
  1287     if ((lock->obj_node() == unlock->obj_node()) &&
  1288             (lock->box_node() == unlock->box_node())) {
  1289       lock_result = lock;
  1292   return lock_result;
  1295 // This code corresponds to case 3 above.
  1297 bool AbstractLockNode::find_lock_and_unlock_through_if(Node* node, LockNode* lock,
  1298                                                        GrowableArray<AbstractLockNode*> &lock_ops) {
  1299   Node* if_node = node->in(0);
  1300   bool  if_true = node->is_IfTrue();
  1302   if (if_node->is_If() && if_node->outcnt() == 2 && (if_true || node->is_IfFalse())) {
  1303     Node *lock_ctrl = next_control(if_node->in(0));
  1304     if (find_matching_unlock(lock_ctrl, lock, lock_ops)) {
  1305       Node* lock1_node = NULL;
  1306       ProjNode* proj = if_node->as_If()->proj_out(!if_true);
  1307       if (if_true) {
  1308         if (proj->is_IfFalse() && proj->outcnt() == 1) {
  1309           lock1_node = proj->unique_out();
  1311       } else {
  1312         if (proj->is_IfTrue() && proj->outcnt() == 1) {
  1313           lock1_node = proj->unique_out();
  1316       if (lock1_node != NULL && lock1_node->is_Lock()) {
  1317         LockNode *lock1 = lock1_node->as_Lock();
  1318         if ((lock->obj_node() == lock1->obj_node()) &&
  1319             (lock->box_node() == lock1->box_node()) && !lock1->is_eliminated()) {
  1320           lock_ops.append(lock1);
  1321           return true;
  1327   lock_ops.trunc_to(0);
  1328   return false;
  1331 bool AbstractLockNode::find_unlocks_for_region(const RegionNode* region, LockNode* lock,
  1332                                GrowableArray<AbstractLockNode*> &lock_ops) {
  1333   // check each control merging at this point for a matching unlock.
  1334   // in(0) should be self edge so skip it.
  1335   for (int i = 1; i < (int)region->req(); i++) {
  1336     Node *in_node = next_control(region->in(i));
  1337     if (in_node != NULL) {
  1338       if (find_matching_unlock(in_node, lock, lock_ops)) {
  1339         // found a match so keep on checking.
  1340         continue;
  1341       } else if (find_lock_and_unlock_through_if(in_node, lock, lock_ops)) {
  1342         continue;
  1345       // If we fall through to here then it was some kind of node we
  1346       // don't understand or there wasn't a matching unlock, so give
  1347       // up trying to merge locks.
  1348       lock_ops.trunc_to(0);
  1349       return false;
  1352   return true;
  1356 #ifndef PRODUCT
  1357 //
  1358 // Create a counter which counts the number of times this lock is acquired
  1359 //
  1360 void AbstractLockNode::create_lock_counter(JVMState* state) {
  1361   _counter = OptoRuntime::new_named_counter(state, NamedCounter::LockCounter);
  1363 #endif
  1365 void AbstractLockNode::set_eliminated() {
  1366   _eliminate = true;
  1367 #ifndef PRODUCT
  1368   if (_counter) {
  1369     // Update the counter to indicate that this lock was eliminated.
  1370     // The counter update code will stay around even though the
  1371     // optimizer will eliminate the lock operation itself.
  1372     _counter->set_tag(NamedCounter::EliminatedLockCounter);
  1374 #endif
  1377 //=============================================================================
  1378 Node *LockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
  1380   // perform any generic optimizations first (returns 'this' or NULL)
  1381   Node *result = SafePointNode::Ideal(phase, can_reshape);
  1383   // Now see if we can optimize away this lock.  We don't actually
  1384   // remove the locking here, we simply set the _eliminate flag which
  1385   // prevents macro expansion from expanding the lock.  Since we don't
  1386   // modify the graph, the value returned from this function is the
  1387   // one computed above.
  1388   if (result == NULL && can_reshape && EliminateLocks && !is_eliminated()) {
  1389     //
  1390     // If we are locking an unescaped object, the lock/unlock is unnecessary
  1391     //
  1392     ConnectionGraph *cgr = phase->C->congraph();
  1393     PointsToNode::EscapeState es = PointsToNode::GlobalEscape;
  1394     if (cgr != NULL)
  1395       es = cgr->escape_state(obj_node(), phase);
  1396     if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
  1397       // Mark it eliminated to update any counters
  1398       this->set_eliminated();
  1399       return result;
  1402     //
  1403     // Try lock coarsening
  1404     //
  1405     PhaseIterGVN* iter = phase->is_IterGVN();
  1406     if (iter != NULL) {
  1408       GrowableArray<AbstractLockNode*>   lock_ops;
  1410       Node *ctrl = next_control(in(0));
  1412       // now search back for a matching Unlock
  1413       if (find_matching_unlock(ctrl, this, lock_ops)) {
  1414         // found an unlock directly preceding this lock.  This is the
  1415         // case of single unlock directly control dependent on a
  1416         // single lock which is the trivial version of case 1 or 2.
  1417       } else if (ctrl->is_Region() ) {
  1418         if (find_unlocks_for_region(ctrl->as_Region(), this, lock_ops)) {
  1419         // found lock preceded by multiple unlocks along all paths
  1420         // joining at this point which is case 3 in description above.
  1422       } else {
  1423         // see if this lock comes from either half of an if and the
  1424         // predecessors merges unlocks and the other half of the if
  1425         // performs a lock.
  1426         if (find_lock_and_unlock_through_if(ctrl, this, lock_ops)) {
  1427           // found unlock splitting to an if with locks on both branches.
  1431       if (lock_ops.length() > 0) {
  1432         // add ourselves to the list of locks to be eliminated.
  1433         lock_ops.append(this);
  1435   #ifndef PRODUCT
  1436         if (PrintEliminateLocks) {
  1437           int locks = 0;
  1438           int unlocks = 0;
  1439           for (int i = 0; i < lock_ops.length(); i++) {
  1440             AbstractLockNode* lock = lock_ops.at(i);
  1441             if (lock->Opcode() == Op_Lock)
  1442               locks++;
  1443             else
  1444               unlocks++;
  1445             if (Verbose) {
  1446               lock->dump(1);
  1449           tty->print_cr("***Eliminated %d unlocks and %d locks", unlocks, locks);
  1451   #endif
  1453         // for each of the identified locks, mark them
  1454         // as eliminatable
  1455         for (int i = 0; i < lock_ops.length(); i++) {
  1456           AbstractLockNode* lock = lock_ops.at(i);
  1458           // Mark it eliminated to update any counters
  1459           lock->set_eliminated();
  1460           lock->set_coarsened();
  1462       } else if (result != NULL && ctrl->is_Region() &&
  1463                  iter->_worklist.member(ctrl)) {
  1464         // We weren't able to find any opportunities but the region this
  1465         // lock is control dependent on hasn't been processed yet so put
  1466         // this lock back on the worklist so we can check again once any
  1467         // region simplification has occurred.
  1468         iter->_worklist.push(this);
  1473   return result;
  1476 //=============================================================================
  1477 uint UnlockNode::size_of() const { return sizeof(*this); }
  1479 //=============================================================================
  1480 Node *UnlockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
  1482   // perform any generic optimizations first (returns 'this' or NULL)
  1483   Node * result = SafePointNode::Ideal(phase, can_reshape);
  1485   // Now see if we can optimize away this unlock.  We don't actually
  1486   // remove the unlocking here, we simply set the _eliminate flag which
  1487   // prevents macro expansion from expanding the unlock.  Since we don't
  1488   // modify the graph, the value returned from this function is the
  1489   // one computed above.
  1490   // Escape state is defined after Parse phase.
  1491   if (result == NULL && can_reshape && EliminateLocks && !is_eliminated()) {
  1492     //
  1493     // If we are unlocking an unescaped object, the lock/unlock is unnecessary.
  1494     //
  1495     ConnectionGraph *cgr = phase->C->congraph();
  1496     PointsToNode::EscapeState es = PointsToNode::GlobalEscape;
  1497     if (cgr != NULL)
  1498       es = cgr->escape_state(obj_node(), phase);
  1499     if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
  1500       // Mark it eliminated to update any counters
  1501       this->set_eliminated();
  1504   return result;

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