1 /*
   2  * Copyright (c) 1997, 2015, 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  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "ci/bcEscapeAnalyzer.hpp"
  28 #include "compiler/oopMap.hpp"
  29 #include "opto/callGenerator.hpp"
  30 #include "opto/callnode.hpp"
  31 #include "opto/escape.hpp"
  32 #include "opto/locknode.hpp"
  33 #include "opto/machnode.hpp"
  34 #include "opto/matcher.hpp"
  35 #include "opto/parse.hpp"
  36 #include "opto/regalloc.hpp"
  37 #include "opto/regmask.hpp"
  38 #include "opto/rootnode.hpp"
  39 #include "opto/runtime.hpp"
  40 
  41 // Portions of code courtesy of Clifford Click
  42 
  43 // Optimization - Graph Style
  44 
  45 //=============================================================================
  46 uint StartNode::size_of() const { return sizeof(*this); }
  47 uint StartNode::cmp( const Node &n ) const
  48 { return _domain == ((StartNode&)n)._domain; }
  49 const Type *StartNode::bottom_type() const { return _domain; }
  50 const Type *StartNode::Value(PhaseTransform *phase) const { return _domain; }
  51 #ifndef PRODUCT
  52 void StartNode::dump_spec(outputStream *st) const { st->print(" #"); _domain->dump_on(st);}
  53 #endif
  54 
  55 //------------------------------Ideal------------------------------------------
  56 Node *StartNode::Ideal(PhaseGVN *phase, bool can_reshape){
  57   return remove_dead_region(phase, can_reshape) ? this : NULL;
  58 }
  59 
  60 //------------------------------calling_convention-----------------------------
  61 void StartNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
  62   Matcher::calling_convention( sig_bt, parm_regs, argcnt, false );
  63 }
  64 
  65 //------------------------------Registers--------------------------------------
  66 const RegMask &StartNode::in_RegMask(uint) const {
  67   return RegMask::Empty;
  68 }
  69 
  70 //------------------------------match------------------------------------------
  71 // Construct projections for incoming parameters, and their RegMask info
  72 Node *StartNode::match( const ProjNode *proj, const Matcher *match ) {
  73   switch (proj->_con) {
  74   case TypeFunc::Control:
  75   case TypeFunc::I_O:
  76   case TypeFunc::Memory:
  77     return new (match->C) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
  78   case TypeFunc::FramePtr:
  79     return new (match->C) MachProjNode(this,proj->_con,Matcher::c_frame_ptr_mask, Op_RegP);
  80   case TypeFunc::ReturnAdr:
  81     return new (match->C) MachProjNode(this,proj->_con,match->_return_addr_mask,Op_RegP);
  82   case TypeFunc::Parms:
  83   default: {
  84       uint parm_num = proj->_con - TypeFunc::Parms;
  85       const Type *t = _domain->field_at(proj->_con);
  86       if (t->base() == Type::Half)  // 2nd half of Longs and Doubles
  87         return new (match->C) ConNode(Type::TOP);
  88       uint ideal_reg = t->ideal_reg();
  89       RegMask &rm = match->_calling_convention_mask[parm_num];
  90       return new (match->C) MachProjNode(this,proj->_con,rm,ideal_reg);
  91     }
  92   }
  93   return NULL;
  94 }
  95 
  96 //------------------------------StartOSRNode----------------------------------
  97 // The method start node for an on stack replacement adapter
  98 
  99 //------------------------------osr_domain-----------------------------
 100 const TypeTuple *StartOSRNode::osr_domain() {
 101   const Type **fields = TypeTuple::fields(2);
 102   fields[TypeFunc::Parms+0] = TypeRawPtr::BOTTOM;  // address of osr buffer
 103 
 104   return TypeTuple::make(TypeFunc::Parms+1, fields);
 105 }
 106 
 107 //=============================================================================
 108 const char * const ParmNode::names[TypeFunc::Parms+1] = {
 109   "Control", "I_O", "Memory", "FramePtr", "ReturnAdr", "Parms"
 110 };
 111 
 112 #ifndef PRODUCT
 113 void ParmNode::dump_spec(outputStream *st) const {
 114   if( _con < TypeFunc::Parms ) {
 115     st->print("%s", names[_con]);
 116   } else {
 117     st->print("Parm%d: ",_con-TypeFunc::Parms);
 118     // Verbose and WizardMode dump bottom_type for all nodes
 119     if( !Verbose && !WizardMode )   bottom_type()->dump_on(st);
 120   }
 121 }
 122 #endif
 123 
 124 uint ParmNode::ideal_reg() const {
 125   switch( _con ) {
 126   case TypeFunc::Control  : // fall through
 127   case TypeFunc::I_O      : // fall through
 128   case TypeFunc::Memory   : return 0;
 129   case TypeFunc::FramePtr : // fall through
 130   case TypeFunc::ReturnAdr: return Op_RegP;
 131   default                 : assert( _con > TypeFunc::Parms, "" );
 132     // fall through
 133   case TypeFunc::Parms    : {
 134     // Type of argument being passed
 135     const Type *t = in(0)->as_Start()->_domain->field_at(_con);
 136     return t->ideal_reg();
 137   }
 138   }
 139   ShouldNotReachHere();
 140   return 0;
 141 }
 142 
 143 //=============================================================================
 144 ReturnNode::ReturnNode(uint edges, Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *retadr ) : Node(edges) {
 145   init_req(TypeFunc::Control,cntrl);
 146   init_req(TypeFunc::I_O,i_o);
 147   init_req(TypeFunc::Memory,memory);
 148   init_req(TypeFunc::FramePtr,frameptr);
 149   init_req(TypeFunc::ReturnAdr,retadr);
 150 }
 151 
 152 Node *ReturnNode::Ideal(PhaseGVN *phase, bool can_reshape){
 153   return remove_dead_region(phase, can_reshape) ? this : NULL;
 154 }
 155 
 156 const Type *ReturnNode::Value( PhaseTransform *phase ) const {
 157   return ( phase->type(in(TypeFunc::Control)) == Type::TOP)
 158     ? Type::TOP
 159     : Type::BOTTOM;
 160 }
 161 
 162 // Do we Match on this edge index or not?  No edges on return nodes
 163 uint ReturnNode::match_edge(uint idx) const {
 164   return 0;
 165 }
 166 
 167 
 168 #ifndef PRODUCT
 169 void ReturnNode::dump_req(outputStream *st) const {
 170   // Dump the required inputs, enclosed in '(' and ')'
 171   uint i;                       // Exit value of loop
 172   for (i = 0; i < req(); i++) {    // For all required inputs
 173     if (i == TypeFunc::Parms) st->print("returns");
 174     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 175     else st->print("_ ");
 176   }
 177 }
 178 #endif
 179 
 180 //=============================================================================
 181 RethrowNode::RethrowNode(
 182   Node* cntrl,
 183   Node* i_o,
 184   Node* memory,
 185   Node* frameptr,
 186   Node* ret_adr,
 187   Node* exception
 188 ) : Node(TypeFunc::Parms + 1) {
 189   init_req(TypeFunc::Control  , cntrl    );
 190   init_req(TypeFunc::I_O      , i_o      );
 191   init_req(TypeFunc::Memory   , memory   );
 192   init_req(TypeFunc::FramePtr , frameptr );
 193   init_req(TypeFunc::ReturnAdr, ret_adr);
 194   init_req(TypeFunc::Parms    , exception);
 195 }
 196 
 197 Node *RethrowNode::Ideal(PhaseGVN *phase, bool can_reshape){
 198   return remove_dead_region(phase, can_reshape) ? this : NULL;
 199 }
 200 
 201 const Type *RethrowNode::Value( PhaseTransform *phase ) const {
 202   return (phase->type(in(TypeFunc::Control)) == Type::TOP)
 203     ? Type::TOP
 204     : Type::BOTTOM;
 205 }
 206 
 207 uint RethrowNode::match_edge(uint idx) const {
 208   return 0;
 209 }
 210 
 211 #ifndef PRODUCT
 212 void RethrowNode::dump_req(outputStream *st) const {
 213   // Dump the required inputs, enclosed in '(' and ')'
 214   uint i;                       // Exit value of loop
 215   for (i = 0; i < req(); i++) {    // For all required inputs
 216     if (i == TypeFunc::Parms) st->print("exception");
 217     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 218     else st->print("_ ");
 219   }
 220 }
 221 #endif
 222 
 223 //=============================================================================
 224 // Do we Match on this edge index or not?  Match only target address & method
 225 uint TailCallNode::match_edge(uint idx) const {
 226   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 227 }
 228 
 229 //=============================================================================
 230 // Do we Match on this edge index or not?  Match only target address & oop
 231 uint TailJumpNode::match_edge(uint idx) const {
 232   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 233 }
 234 
 235 //=============================================================================
 236 JVMState::JVMState(ciMethod* method, JVMState* caller) :
 237   _method(method) {
 238   assert(method != NULL, "must be valid call site");
 239   _reexecute = Reexecute_Undefined;
 240   debug_only(_bci = -99);  // random garbage value
 241   debug_only(_map = (SafePointNode*)-1);
 242   _caller = caller;
 243   _depth  = 1 + (caller == NULL ? 0 : caller->depth());
 244   _locoff = TypeFunc::Parms;
 245   _stkoff = _locoff + _method->max_locals();
 246   _monoff = _stkoff + _method->max_stack();
 247   _scloff = _monoff;
 248   _endoff = _monoff;
 249   _sp = 0;
 250 }
 251 JVMState::JVMState(int stack_size) :
 252   _method(NULL) {
 253   _bci = InvocationEntryBci;
 254   _reexecute = Reexecute_Undefined;
 255   debug_only(_map = (SafePointNode*)-1);
 256   _caller = NULL;
 257   _depth  = 1;
 258   _locoff = TypeFunc::Parms;
 259   _stkoff = _locoff;
 260   _monoff = _stkoff + stack_size;
 261   _scloff = _monoff;
 262   _endoff = _monoff;
 263   _sp = 0;
 264 }
 265 
 266 //--------------------------------of_depth-------------------------------------
 267 JVMState* JVMState::of_depth(int d) const {
 268   const JVMState* jvmp = this;
 269   assert(0 < d && (uint)d <= depth(), "oob");
 270   for (int skip = depth() - d; skip > 0; skip--) {
 271     jvmp = jvmp->caller();
 272   }
 273   assert(jvmp->depth() == (uint)d, "found the right one");
 274   return (JVMState*)jvmp;
 275 }
 276 
 277 //-----------------------------same_calls_as-----------------------------------
 278 bool JVMState::same_calls_as(const JVMState* that) const {
 279   if (this == that)                    return true;
 280   if (this->depth() != that->depth())  return false;
 281   const JVMState* p = this;
 282   const JVMState* q = that;
 283   for (;;) {
 284     if (p->_method != q->_method)    return false;
 285     if (p->_method == NULL)          return true;   // bci is irrelevant
 286     if (p->_bci    != q->_bci)       return false;
 287     if (p->_reexecute != q->_reexecute)  return false;
 288     p = p->caller();
 289     q = q->caller();
 290     if (p == q)                      return true;
 291     assert(p != NULL && q != NULL, "depth check ensures we don't run off end");
 292   }
 293 }
 294 
 295 //------------------------------debug_start------------------------------------
 296 uint JVMState::debug_start()  const {
 297   debug_only(JVMState* jvmroot = of_depth(1));
 298   assert(jvmroot->locoff() <= this->locoff(), "youngest JVMState must be last");
 299   return of_depth(1)->locoff();
 300 }
 301 
 302 //-------------------------------debug_end-------------------------------------
 303 uint JVMState::debug_end() const {
 304   debug_only(JVMState* jvmroot = of_depth(1));
 305   assert(jvmroot->endoff() <= this->endoff(), "youngest JVMState must be last");
 306   return endoff();
 307 }
 308 
 309 //------------------------------debug_depth------------------------------------
 310 uint JVMState::debug_depth() const {
 311   uint total = 0;
 312   for (const JVMState* jvmp = this; jvmp != NULL; jvmp = jvmp->caller()) {
 313     total += jvmp->debug_size();
 314   }
 315   return total;
 316 }
 317 
 318 #ifndef PRODUCT
 319 
 320 //------------------------------format_helper----------------------------------
 321 // Given an allocation (a Chaitin object) and a Node decide if the Node carries
 322 // any defined value or not.  If it does, print out the register or constant.
 323 static void format_helper( PhaseRegAlloc *regalloc, outputStream* st, Node *n, const char *msg, uint i, GrowableArray<SafePointScalarObjectNode*> *scobjs ) {
 324   if (n == NULL) { st->print(" NULL"); return; }
 325   if (n->is_SafePointScalarObject()) {
 326     // Scalar replacement.
 327     SafePointScalarObjectNode* spobj = n->as_SafePointScalarObject();
 328     scobjs->append_if_missing(spobj);
 329     int sco_n = scobjs->find(spobj);
 330     assert(sco_n >= 0, "");
 331     st->print(" %s%d]=#ScObj" INT32_FORMAT, msg, i, sco_n);
 332     return;
 333   }
 334   if (regalloc->node_regs_max_index() > 0 &&
 335       OptoReg::is_valid(regalloc->get_reg_first(n))) { // Check for undefined
 336     char buf[50];
 337     regalloc->dump_register(n,buf);
 338     st->print(" %s%d]=%s",msg,i,buf);
 339   } else {                      // No register, but might be constant
 340     const Type *t = n->bottom_type();
 341     switch (t->base()) {
 342     case Type::Int:
 343       st->print(" %s%d]=#" INT32_FORMAT,msg,i,t->is_int()->get_con());
 344       break;
 345     case Type::AnyPtr:
 346       assert( t == TypePtr::NULL_PTR || n->in_dump(), "" );
 347       st->print(" %s%d]=#NULL",msg,i);
 348       break;
 349     case Type::AryPtr:
 350     case Type::InstPtr:
 351       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->isa_oopptr()->const_oop()));
 352       break;
 353     case Type::KlassPtr:
 354       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_klassptr()->klass()));
 355       break;
 356     case Type::MetadataPtr:
 357       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_metadataptr()->metadata()));
 358       break;
 359     case Type::NarrowOop:
 360       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_oopptr()->const_oop()));
 361       break;
 362     case Type::RawPtr:
 363       st->print(" %s%d]=#Raw" INTPTR_FORMAT,msg,i,p2i(t->is_rawptr()));
 364       break;
 365     case Type::DoubleCon:
 366       st->print(" %s%d]=#%fD",msg,i,t->is_double_constant()->_d);
 367       break;
 368     case Type::FloatCon:
 369       st->print(" %s%d]=#%fF",msg,i,t->is_float_constant()->_f);
 370       break;
 371     case Type::Long:
 372       st->print(" %s%d]=#" INT64_FORMAT,msg,i,(int64_t)(t->is_long()->get_con()));
 373       break;
 374     case Type::Half:
 375     case Type::Top:
 376       st->print(" %s%d]=_",msg,i);
 377       break;
 378     default: ShouldNotReachHere();
 379     }
 380   }
 381 }
 382 
 383 //------------------------------format-----------------------------------------
 384 void JVMState::format(PhaseRegAlloc *regalloc, const Node *n, outputStream* st) const {
 385   st->print("        #");
 386   if (_method) {
 387     _method->print_short_name(st);
 388     st->print(" @ bci:%d ",_bci);
 389   } else {
 390     st->print_cr(" runtime stub ");
 391     return;
 392   }
 393   if (n->is_MachSafePoint()) {
 394     GrowableArray<SafePointScalarObjectNode*> scobjs;
 395     MachSafePointNode *mcall = n->as_MachSafePoint();
 396     uint i;
 397     // Print locals
 398     for (i = 0; i < (uint)loc_size(); i++)
 399       format_helper(regalloc, st, mcall->local(this, i), "L[", i, &scobjs);
 400     // Print stack
 401     for (i = 0; i < (uint)stk_size(); i++) {
 402       if ((uint)(_stkoff + i) >= mcall->len())
 403         st->print(" oob ");
 404       else
 405        format_helper(regalloc, st, mcall->stack(this, i), "STK[", i, &scobjs);
 406     }
 407     for (i = 0; (int)i < nof_monitors(); i++) {
 408       Node *box = mcall->monitor_box(this, i);
 409       Node *obj = mcall->monitor_obj(this, i);
 410       if (regalloc->node_regs_max_index() > 0 &&
 411           OptoReg::is_valid(regalloc->get_reg_first(box))) {
 412         box = BoxLockNode::box_node(box);
 413         format_helper(regalloc, st, box, "MON-BOX[", i, &scobjs);
 414       } else {
 415         OptoReg::Name box_reg = BoxLockNode::reg(box);
 416         st->print(" MON-BOX%d=%s+%d",
 417                    i,
 418                    OptoReg::regname(OptoReg::c_frame_pointer),
 419                    regalloc->reg2offset(box_reg));
 420       }
 421       const char* obj_msg = "MON-OBJ[";
 422       if (EliminateLocks) {
 423         if (BoxLockNode::box_node(box)->is_eliminated())
 424           obj_msg = "MON-OBJ(LOCK ELIMINATED)[";
 425       }
 426       format_helper(regalloc, st, obj, obj_msg, i, &scobjs);
 427     }
 428 
 429     for (i = 0; i < (uint)scobjs.length(); i++) {
 430       // Scalar replaced objects.
 431       st->cr();
 432       st->print("        # ScObj" INT32_FORMAT " ", i);
 433       SafePointScalarObjectNode* spobj = scobjs.at(i);
 434       ciKlass* cik = spobj->bottom_type()->is_oopptr()->klass();
 435       assert(cik->is_instance_klass() ||
 436              cik->is_array_klass(), "Not supported allocation.");
 437       ciInstanceKlass *iklass = NULL;
 438       if (cik->is_instance_klass()) {
 439         cik->print_name_on(st);
 440         iklass = cik->as_instance_klass();
 441       } else if (cik->is_type_array_klass()) {
 442         cik->as_array_klass()->base_element_type()->print_name_on(st);
 443         st->print("[%d]", spobj->n_fields());
 444       } else if (cik->is_obj_array_klass()) {
 445         ciKlass* cie = cik->as_obj_array_klass()->base_element_klass();
 446         if (cie->is_instance_klass()) {
 447           cie->print_name_on(st);
 448         } else if (cie->is_type_array_klass()) {
 449           cie->as_array_klass()->base_element_type()->print_name_on(st);
 450         } else {
 451           ShouldNotReachHere();
 452         }
 453         st->print("[%d]", spobj->n_fields());
 454         int ndim = cik->as_array_klass()->dimension() - 1;
 455         while (ndim-- > 0) {
 456           st->print("[]");
 457         }
 458       }
 459       st->print("={");
 460       uint nf = spobj->n_fields();
 461       if (nf > 0) {
 462         uint first_ind = spobj->first_index(mcall->jvms());
 463         Node* fld_node = mcall->in(first_ind);
 464         ciField* cifield;
 465         if (iklass != NULL) {
 466           st->print(" [");
 467           cifield = iklass->nonstatic_field_at(0);
 468           cifield->print_name_on(st);
 469           format_helper(regalloc, st, fld_node, ":", 0, &scobjs);
 470         } else {
 471           format_helper(regalloc, st, fld_node, "[", 0, &scobjs);
 472         }
 473         for (uint j = 1; j < nf; j++) {
 474           fld_node = mcall->in(first_ind+j);
 475           if (iklass != NULL) {
 476             st->print(", [");
 477             cifield = iklass->nonstatic_field_at(j);
 478             cifield->print_name_on(st);
 479             format_helper(regalloc, st, fld_node, ":", j, &scobjs);
 480           } else {
 481             format_helper(regalloc, st, fld_node, ", [", j, &scobjs);
 482           }
 483         }
 484       }
 485       st->print(" }");
 486     }
 487   }
 488   st->cr();
 489   if (caller() != NULL) caller()->format(regalloc, n, st);
 490 }
 491 
 492 
 493 void JVMState::dump_spec(outputStream *st) const {
 494   if (_method != NULL) {
 495     bool printed = false;
 496     if (!Verbose) {
 497       // The JVMS dumps make really, really long lines.
 498       // Take out the most boring parts, which are the package prefixes.
 499       char buf[500];
 500       stringStream namest(buf, sizeof(buf));
 501       _method->print_short_name(&namest);
 502       if (namest.count() < sizeof(buf)) {
 503         const char* name = namest.base();
 504         if (name[0] == ' ')  ++name;
 505         const char* endcn = strchr(name, ':');  // end of class name
 506         if (endcn == NULL)  endcn = strchr(name, '(');
 507         if (endcn == NULL)  endcn = name + strlen(name);
 508         while (endcn > name && endcn[-1] != '.' && endcn[-1] != '/')
 509           --endcn;
 510         st->print(" %s", endcn);
 511         printed = true;
 512       }
 513     }
 514     if (!printed)
 515       _method->print_short_name(st);
 516     st->print(" @ bci:%d",_bci);
 517     if(_reexecute == Reexecute_True)
 518       st->print(" reexecute");
 519   } else {
 520     st->print(" runtime stub");
 521   }
 522   if (caller() != NULL)  caller()->dump_spec(st);
 523 }
 524 
 525 
 526 void JVMState::dump_on(outputStream* st) const {
 527   bool print_map = _map && !((uintptr_t)_map & 1) &&
 528                   ((caller() == NULL) || (caller()->map() != _map));
 529   if (print_map) {
 530     if (_map->len() > _map->req()) {  // _map->has_exceptions()
 531       Node* ex = _map->in(_map->req());  // _map->next_exception()
 532       // skip the first one; it's already being printed
 533       while (ex != NULL && ex->len() > ex->req()) {
 534         ex = ex->in(ex->req());  // ex->next_exception()
 535         ex->dump(1);
 536       }
 537     }
 538     _map->dump(Verbose ? 2 : 1);
 539   }
 540   if (caller() != NULL) {
 541     caller()->dump_on(st);
 542   }
 543   st->print("JVMS depth=%d loc=%d stk=%d arg=%d mon=%d scalar=%d end=%d mondepth=%d sp=%d bci=%d reexecute=%s method=",
 544              depth(), locoff(), stkoff(), argoff(), monoff(), scloff(), endoff(), monitor_depth(), sp(), bci(), should_reexecute()?"true":"false");
 545   if (_method == NULL) {
 546     st->print_cr("(none)");
 547   } else {
 548     _method->print_name(st);
 549     st->cr();
 550     if (bci() >= 0 && bci() < _method->code_size()) {
 551       st->print("    bc: ");
 552       _method->print_codes_on(bci(), bci()+1, st);
 553     }
 554   }
 555 }
 556 
 557 // Extra way to dump a jvms from the debugger,
 558 // to avoid a bug with C++ member function calls.
 559 void dump_jvms(JVMState* jvms) {
 560   jvms->dump();
 561 }
 562 #endif
 563 
 564 //--------------------------clone_shallow--------------------------------------
 565 JVMState* JVMState::clone_shallow(Compile* C) const {
 566   JVMState* n = has_method() ? new (C) JVMState(_method, _caller) : new (C) JVMState(0);
 567   n->set_bci(_bci);
 568   n->_reexecute = _reexecute;
 569   n->set_locoff(_locoff);
 570   n->set_stkoff(_stkoff);
 571   n->set_monoff(_monoff);
 572   n->set_scloff(_scloff);
 573   n->set_endoff(_endoff);
 574   n->set_sp(_sp);
 575   n->set_map(_map);
 576   return n;
 577 }
 578 
 579 //---------------------------clone_deep----------------------------------------
 580 JVMState* JVMState::clone_deep(Compile* C) const {
 581   JVMState* n = clone_shallow(C);
 582   for (JVMState* p = n; p->_caller != NULL; p = p->_caller) {
 583     p->_caller = p->_caller->clone_shallow(C);
 584   }
 585   assert(n->depth() == depth(), "sanity");
 586   assert(n->debug_depth() == debug_depth(), "sanity");
 587   return n;
 588 }
 589 
 590 /**
 591  * Reset map for all callers
 592  */
 593 void JVMState::set_map_deep(SafePointNode* map) {
 594   for (JVMState* p = this; p->_caller != NULL; p = p->_caller) {
 595     p->set_map(map);
 596   }
 597 }
 598 
 599 // Adapt offsets in in-array after adding or removing an edge.
 600 // Prerequisite is that the JVMState is used by only one node.
 601 void JVMState::adapt_position(int delta) {
 602   for (JVMState* jvms = this; jvms != NULL; jvms = jvms->caller()) {
 603     jvms->set_locoff(jvms->locoff() + delta);
 604     jvms->set_stkoff(jvms->stkoff() + delta);
 605     jvms->set_monoff(jvms->monoff() + delta);
 606     jvms->set_scloff(jvms->scloff() + delta);
 607     jvms->set_endoff(jvms->endoff() + delta);
 608   }
 609 }
 610 
 611 // Mirror the stack size calculation in the deopt code
 612 // How much stack space would we need at this point in the program in
 613 // case of deoptimization?
 614 int JVMState::interpreter_frame_size() const {
 615   const JVMState* jvms = this;
 616   int size = 0;
 617   int callee_parameters = 0;
 618   int callee_locals = 0;
 619   int extra_args = method()->max_stack() - stk_size();
 620 
 621   while (jvms != NULL) {
 622     int locks = jvms->nof_monitors();
 623     int temps = jvms->stk_size();
 624     bool is_top_frame = (jvms == this);
 625     ciMethod* method = jvms->method();
 626 
 627     int frame_size = BytesPerWord * Interpreter::size_activation(method->max_stack(),
 628                                                                  temps + callee_parameters,
 629                                                                  extra_args,
 630                                                                  locks,
 631                                                                  callee_parameters,
 632                                                                  callee_locals,
 633                                                                  is_top_frame);
 634     size += frame_size;
 635 
 636     callee_parameters = method->size_of_parameters();
 637     callee_locals = method->max_locals();
 638     extra_args = 0;
 639     jvms = jvms->caller();
 640   }
 641   return size + Deoptimization::last_frame_adjust(0, callee_locals) * BytesPerWord;
 642 }
 643 
 644 //=============================================================================
 645 uint CallNode::cmp( const Node &n ) const
 646 { return _tf == ((CallNode&)n)._tf && _jvms == ((CallNode&)n)._jvms; }
 647 #ifndef PRODUCT
 648 void CallNode::dump_req(outputStream *st) const {
 649   // Dump the required inputs, enclosed in '(' and ')'
 650   uint i;                       // Exit value of loop
 651   for (i = 0; i < req(); i++) {    // For all required inputs
 652     if (i == TypeFunc::Parms) st->print("(");
 653     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 654     else st->print("_ ");
 655   }
 656   st->print(")");
 657 }
 658 
 659 void CallNode::dump_spec(outputStream *st) const {
 660   st->print(" ");
 661   tf()->dump_on(st);
 662   if (_cnt != COUNT_UNKNOWN)  st->print(" C=%f",_cnt);
 663   if (jvms() != NULL)  jvms()->dump_spec(st);
 664 }
 665 #endif
 666 
 667 const Type *CallNode::bottom_type() const { return tf()->range(); }
 668 const Type *CallNode::Value(PhaseTransform *phase) const {
 669   if (phase->type(in(0)) == Type::TOP)  return Type::TOP;
 670   return tf()->range();
 671 }
 672 
 673 //------------------------------calling_convention-----------------------------
 674 void CallNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
 675   // Use the standard compiler calling convention
 676   Matcher::calling_convention( sig_bt, parm_regs, argcnt, true );
 677 }
 678 
 679 
 680 //------------------------------match------------------------------------------
 681 // Construct projections for control, I/O, memory-fields, ..., and
 682 // return result(s) along with their RegMask info
 683 Node *CallNode::match( const ProjNode *proj, const Matcher *match ) {
 684   switch (proj->_con) {
 685   case TypeFunc::Control:
 686   case TypeFunc::I_O:
 687   case TypeFunc::Memory:
 688     return new (match->C) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
 689 
 690   case TypeFunc::Parms+1:       // For LONG & DOUBLE returns
 691     assert(tf()->_range->field_at(TypeFunc::Parms+1) == Type::HALF, "");
 692     // 2nd half of doubles and longs
 693     return new (match->C) MachProjNode(this,proj->_con, RegMask::Empty, (uint)OptoReg::Bad);
 694 
 695   case TypeFunc::Parms: {       // Normal returns
 696     uint ideal_reg = tf()->range()->field_at(TypeFunc::Parms)->ideal_reg();
 697     OptoRegPair regs = is_CallRuntime()
 698       ? match->c_return_value(ideal_reg,true)  // Calls into C runtime
 699       : match->  return_value(ideal_reg,true); // Calls into compiled Java code
 700     RegMask rm = RegMask(regs.first());
 701     if( OptoReg::is_valid(regs.second()) )
 702       rm.Insert( regs.second() );
 703     return new (match->C) MachProjNode(this,proj->_con,rm,ideal_reg);
 704   }
 705 
 706   case TypeFunc::ReturnAdr:
 707   case TypeFunc::FramePtr:
 708   default:
 709     ShouldNotReachHere();
 710   }
 711   return NULL;
 712 }
 713 
 714 // Do we Match on this edge index or not?  Match no edges
 715 uint CallNode::match_edge(uint idx) const {
 716   return 0;
 717 }
 718 
 719 //
 720 // Determine whether the call could modify the field of the specified
 721 // instance at the specified offset.
 722 //
 723 bool CallNode::may_modify(const TypeOopPtr *t_oop, PhaseTransform *phase) {
 724   assert((t_oop != NULL), "sanity");
 725   if (t_oop->is_known_instance()) {
 726     // The instance_id is set only for scalar-replaceable allocations which
 727     // are not passed as arguments according to Escape Analysis.
 728     return false;
 729   }
 730   if (t_oop->is_ptr_to_boxed_value()) {
 731     ciKlass* boxing_klass = t_oop->klass();
 732     if (is_CallStaticJava() && as_CallStaticJava()->is_boxing_method()) {
 733       // Skip unrelated boxing methods.
 734       Node* proj = proj_out(TypeFunc::Parms);
 735       if ((proj == NULL) || (phase->type(proj)->is_instptr()->klass() != boxing_klass)) {
 736         return false;
 737       }
 738     }
 739     if (is_CallJava() && as_CallJava()->method() != NULL) {
 740       ciMethod* meth = as_CallJava()->method();
 741       if (meth->is_accessor()) {
 742         return false;
 743       }
 744       // May modify (by reflection) if an boxing object is passed
 745       // as argument or returned.
 746       Node* proj = returns_pointer() ? proj_out(TypeFunc::Parms) : NULL;
 747       if (proj != NULL) {
 748         const TypeInstPtr* inst_t = phase->type(proj)->isa_instptr();
 749         if ((inst_t != NULL) && (!inst_t->klass_is_exact() ||
 750                                  (inst_t->klass() == boxing_klass))) {
 751           return true;
 752         }
 753       }
 754       const TypeTuple* d = tf()->domain();
 755       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 756         const TypeInstPtr* inst_t = d->field_at(i)->isa_instptr();
 757         if ((inst_t != NULL) && (!inst_t->klass_is_exact() ||
 758                                  (inst_t->klass() == boxing_klass))) {
 759           return true;
 760         }
 761       }
 762       return false;
 763     }
 764   }
 765   return true;
 766 }
 767 
 768 // Does this call have a direct reference to n other than debug information?
 769 bool CallNode::has_non_debug_use(Node *n) {
 770   const TypeTuple * d = tf()->domain();
 771   for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 772     Node *arg = in(i);
 773     if (arg == n) {
 774       return true;
 775     }
 776   }
 777   return false;
 778 }
 779 
 780 // Returns the unique CheckCastPP of a call
 781 // or 'this' if there are several CheckCastPP or unexpected uses
 782 // or returns NULL if there is no one.
 783 Node *CallNode::result_cast() {
 784   Node *cast = NULL;
 785 
 786   Node *p = proj_out(TypeFunc::Parms);
 787   if (p == NULL)
 788     return NULL;
 789 
 790   for (DUIterator_Fast imax, i = p->fast_outs(imax); i < imax; i++) {
 791     Node *use = p->fast_out(i);
 792     if (use->is_CheckCastPP()) {
 793       if (cast != NULL) {
 794         return this;  // more than 1 CheckCastPP
 795       }
 796       cast = use;
 797     } else if (!use->is_Initialize() &&
 798                !use->is_AddP()) {
 799       // Expected uses are restricted to a CheckCastPP, an Initialize
 800       // node, and AddP nodes. If we encounter any other use (a Phi
 801       // node can be seen in rare cases) return this to prevent
 802       // incorrect optimizations.
 803       return this;
 804     }
 805   }
 806   return cast;
 807 }
 808 
 809 
 810 void CallNode::extract_projections(CallProjections* projs, bool separate_io_proj) {
 811   projs->fallthrough_proj      = NULL;
 812   projs->fallthrough_catchproj = NULL;
 813   projs->fallthrough_ioproj    = NULL;
 814   projs->catchall_ioproj       = NULL;
 815   projs->catchall_catchproj    = NULL;
 816   projs->fallthrough_memproj   = NULL;
 817   projs->catchall_memproj      = NULL;
 818   projs->resproj               = NULL;
 819   projs->exobj                 = NULL;
 820 
 821   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 822     ProjNode *pn = fast_out(i)->as_Proj();
 823     if (pn->outcnt() == 0) continue;
 824     switch (pn->_con) {
 825     case TypeFunc::Control:
 826       {
 827         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 828         projs->fallthrough_proj = pn;
 829         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 830         const Node *cn = pn->fast_out(j);
 831         if (cn->is_Catch()) {
 832           ProjNode *cpn = NULL;
 833           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 834             cpn = cn->fast_out(k)->as_Proj();
 835             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 836             if (cpn->_con == CatchProjNode::fall_through_index)
 837               projs->fallthrough_catchproj = cpn;
 838             else {
 839               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 840               projs->catchall_catchproj = cpn;
 841             }
 842           }
 843         }
 844         break;
 845       }
 846     case TypeFunc::I_O:
 847       if (pn->_is_io_use)
 848         projs->catchall_ioproj = pn;
 849       else
 850         projs->fallthrough_ioproj = pn;
 851       for (DUIterator j = pn->outs(); pn->has_out(j); j++) {
 852         Node* e = pn->out(j);
 853         if (e->Opcode() == Op_CreateEx && e->in(0)->is_CatchProj() && e->outcnt() > 0) {
 854           assert(projs->exobj == NULL, "only one");
 855           projs->exobj = e;
 856         }
 857       }
 858       break;
 859     case TypeFunc::Memory:
 860       if (pn->_is_io_use)
 861         projs->catchall_memproj = pn;
 862       else
 863         projs->fallthrough_memproj = pn;
 864       break;
 865     case TypeFunc::Parms:
 866       projs->resproj = pn;
 867       break;
 868     default:
 869       assert(false, "unexpected projection from allocation node.");
 870     }
 871   }
 872 
 873   // The resproj may not exist because the result couuld be ignored
 874   // and the exception object may not exist if an exception handler
 875   // swallows the exception but all the other must exist and be found.
 876   assert(projs->fallthrough_proj      != NULL, "must be found");
 877   assert(Compile::current()->inlining_incrementally() || projs->fallthrough_catchproj != NULL, "must be found");
 878   assert(Compile::current()->inlining_incrementally() || projs->fallthrough_memproj   != NULL, "must be found");
 879   assert(Compile::current()->inlining_incrementally() || projs->fallthrough_ioproj    != NULL, "must be found");
 880   assert(Compile::current()->inlining_incrementally() || projs->catchall_catchproj    != NULL, "must be found");
 881   if (separate_io_proj) {
 882     assert(Compile::current()->inlining_incrementally() || projs->catchall_memproj    != NULL, "must be found");
 883     assert(Compile::current()->inlining_incrementally() || projs->catchall_ioproj     != NULL, "must be found");
 884   }
 885 }
 886 
 887 Node *CallNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 888   CallGenerator* cg = generator();
 889   if (can_reshape && cg != NULL && cg->is_mh_late_inline() && !cg->already_attempted()) {
 890     // Check whether this MH handle call becomes a candidate for inlining
 891     ciMethod* callee = cg->method();
 892     vmIntrinsics::ID iid = callee->intrinsic_id();
 893     if (iid == vmIntrinsics::_invokeBasic) {
 894       if (in(TypeFunc::Parms)->Opcode() == Op_ConP) {
 895         phase->C->prepend_late_inline(cg);
 896         set_generator(NULL);
 897       }
 898     } else {
 899       assert(callee->has_member_arg(), "wrong type of call?");
 900       if (in(TypeFunc::Parms + callee->arg_size() - 1)->Opcode() == Op_ConP) {
 901         phase->C->prepend_late_inline(cg);
 902         set_generator(NULL);
 903       }
 904     }
 905   }
 906   return SafePointNode::Ideal(phase, can_reshape);
 907 }
 908 
 909 
 910 //=============================================================================
 911 uint CallJavaNode::size_of() const { return sizeof(*this); }
 912 uint CallJavaNode::cmp( const Node &n ) const {
 913   CallJavaNode &call = (CallJavaNode&)n;
 914   return CallNode::cmp(call) && _method == call._method;
 915 }
 916 #ifndef PRODUCT
 917 void CallJavaNode::dump_spec(outputStream *st) const {
 918   if( _method ) _method->print_short_name(st);
 919   CallNode::dump_spec(st);
 920 }
 921 #endif
 922 
 923 //=============================================================================
 924 uint CallStaticJavaNode::size_of() const { return sizeof(*this); }
 925 uint CallStaticJavaNode::cmp( const Node &n ) const {
 926   CallStaticJavaNode &call = (CallStaticJavaNode&)n;
 927   return CallJavaNode::cmp(call);
 928 }
 929 
 930 //----------------------------uncommon_trap_request----------------------------
 931 // If this is an uncommon trap, return the request code, else zero.
 932 int CallStaticJavaNode::uncommon_trap_request() const {
 933   if (_name != NULL && !strcmp(_name, "uncommon_trap")) {
 934     return extract_uncommon_trap_request(this);
 935   }
 936   return 0;
 937 }
 938 int CallStaticJavaNode::extract_uncommon_trap_request(const Node* call) {
 939 #ifndef PRODUCT
 940   if (!(call->req() > TypeFunc::Parms &&
 941         call->in(TypeFunc::Parms) != NULL &&
 942         call->in(TypeFunc::Parms)->is_Con())) {
 943     assert(in_dump() != 0, "OK if dumping");
 944     tty->print("[bad uncommon trap]");
 945     return 0;
 946   }
 947 #endif
 948   return call->in(TypeFunc::Parms)->bottom_type()->is_int()->get_con();
 949 }
 950 
 951 #ifndef PRODUCT
 952 void CallStaticJavaNode::dump_spec(outputStream *st) const {
 953   st->print("# Static ");
 954   if (_name != NULL) {
 955     st->print("%s", _name);
 956     int trap_req = uncommon_trap_request();
 957     if (trap_req != 0) {
 958       char buf[100];
 959       st->print("(%s)",
 960                  Deoptimization::format_trap_request(buf, sizeof(buf),
 961                                                      trap_req));
 962     }
 963     st->print(" ");
 964   }
 965   CallJavaNode::dump_spec(st);
 966 }
 967 #endif
 968 
 969 //=============================================================================
 970 uint CallDynamicJavaNode::size_of() const { return sizeof(*this); }
 971 uint CallDynamicJavaNode::cmp( const Node &n ) const {
 972   CallDynamicJavaNode &call = (CallDynamicJavaNode&)n;
 973   return CallJavaNode::cmp(call);
 974 }
 975 #ifndef PRODUCT
 976 void CallDynamicJavaNode::dump_spec(outputStream *st) const {
 977   st->print("# Dynamic ");
 978   CallJavaNode::dump_spec(st);
 979 }
 980 #endif
 981 
 982 //=============================================================================
 983 uint CallRuntimeNode::size_of() const { return sizeof(*this); }
 984 uint CallRuntimeNode::cmp( const Node &n ) const {
 985   CallRuntimeNode &call = (CallRuntimeNode&)n;
 986   return CallNode::cmp(call) && !strcmp(_name,call._name);
 987 }
 988 #ifndef PRODUCT
 989 void CallRuntimeNode::dump_spec(outputStream *st) const {
 990   st->print("# ");
 991   st->print("%s", _name);
 992   CallNode::dump_spec(st);
 993 }
 994 #endif
 995 
 996 //------------------------------calling_convention-----------------------------
 997 void CallRuntimeNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
 998   Matcher::c_calling_convention( sig_bt, parm_regs, argcnt );
 999 }
1000 
1001 //=============================================================================
1002 //------------------------------calling_convention-----------------------------
1003 
1004 
1005 //=============================================================================
1006 #ifndef PRODUCT
1007 void CallLeafNode::dump_spec(outputStream *st) const {
1008   st->print("# ");
1009   st->print("%s", _name);
1010   CallNode::dump_spec(st);
1011 }
1012 #endif
1013 
1014 //=============================================================================
1015 
1016 void SafePointNode::set_local(JVMState* jvms, uint idx, Node *c) {
1017   assert(verify_jvms(jvms), "jvms must match");
1018   int loc = jvms->locoff() + idx;
1019   if (in(loc)->is_top() && idx > 0 && !c->is_top() ) {
1020     // If current local idx is top then local idx - 1 could
1021     // be a long/double that needs to be killed since top could
1022     // represent the 2nd half ofthe long/double.
1023     uint ideal = in(loc -1)->ideal_reg();
1024     if (ideal == Op_RegD || ideal == Op_RegL) {
1025       // set other (low index) half to top
1026       set_req(loc - 1, in(loc));
1027     }
1028   }
1029   set_req(loc, c);
1030 }
1031 
1032 uint SafePointNode::size_of() const { return sizeof(*this); }
1033 uint SafePointNode::cmp( const Node &n ) const {
1034   return (&n == this);          // Always fail except on self
1035 }
1036 
1037 //-------------------------set_next_exception----------------------------------
1038 void SafePointNode::set_next_exception(SafePointNode* n) {
1039   assert(n == NULL || n->Opcode() == Op_SafePoint, "correct value for next_exception");
1040   if (len() == req()) {
1041     if (n != NULL)  add_prec(n);
1042   } else {
1043     set_prec(req(), n);
1044   }
1045 }
1046 
1047 
1048 //----------------------------next_exception-----------------------------------
1049 SafePointNode* SafePointNode::next_exception() const {
1050   if (len() == req()) {
1051     return NULL;
1052   } else {
1053     Node* n = in(req());
1054     assert(n == NULL || n->Opcode() == Op_SafePoint, "no other uses of prec edges");
1055     return (SafePointNode*) n;
1056   }
1057 }
1058 
1059 
1060 //------------------------------Ideal------------------------------------------
1061 // Skip over any collapsed Regions
1062 Node *SafePointNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1063   return remove_dead_region(phase, can_reshape) ? this : NULL;
1064 }
1065 
1066 //------------------------------Identity---------------------------------------
1067 // Remove obviously duplicate safepoints
1068 Node *SafePointNode::Identity( PhaseTransform *phase ) {
1069 
1070   // If you have back to back safepoints, remove one
1071   if( in(TypeFunc::Control)->is_SafePoint() )
1072     return in(TypeFunc::Control);
1073 
1074   if( in(0)->is_Proj() ) {
1075     Node *n0 = in(0)->in(0);
1076     // Check if he is a call projection (except Leaf Call)
1077     if( n0->is_Catch() ) {
1078       n0 = n0->in(0)->in(0);
1079       assert( n0->is_Call(), "expect a call here" );
1080     }
1081     if( n0->is_Call() && n0->as_Call()->guaranteed_safepoint() ) {
1082       // Useless Safepoint, so remove it
1083       return in(TypeFunc::Control);
1084     }
1085   }
1086 
1087   return this;
1088 }
1089 
1090 //------------------------------Value------------------------------------------
1091 const Type *SafePointNode::Value( PhaseTransform *phase ) const {
1092   if( phase->type(in(0)) == Type::TOP ) return Type::TOP;
1093   if( phase->eqv( in(0), this ) ) return Type::TOP; // Dead infinite loop
1094   return Type::CONTROL;
1095 }
1096 
1097 #ifndef PRODUCT
1098 void SafePointNode::dump_spec(outputStream *st) const {
1099   st->print(" SafePoint ");
1100   _replaced_nodes.dump(st);
1101 }
1102 #endif
1103 
1104 const RegMask &SafePointNode::in_RegMask(uint idx) const {
1105   if( idx < TypeFunc::Parms ) return RegMask::Empty;
1106   // Values outside the domain represent debug info
1107   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
1108 }
1109 const RegMask &SafePointNode::out_RegMask() const {
1110   return RegMask::Empty;
1111 }
1112 
1113 
1114 void SafePointNode::grow_stack(JVMState* jvms, uint grow_by) {
1115   assert((int)grow_by > 0, "sanity");
1116   int monoff = jvms->monoff();
1117   int scloff = jvms->scloff();
1118   int endoff = jvms->endoff();
1119   assert(endoff == (int)req(), "no other states or debug info after me");
1120   Node* top = Compile::current()->top();
1121   for (uint i = 0; i < grow_by; i++) {
1122     ins_req(monoff, top);
1123   }
1124   jvms->set_monoff(monoff + grow_by);
1125   jvms->set_scloff(scloff + grow_by);
1126   jvms->set_endoff(endoff + grow_by);
1127 }
1128 
1129 void SafePointNode::push_monitor(const FastLockNode *lock) {
1130   // Add a LockNode, which points to both the original BoxLockNode (the
1131   // stack space for the monitor) and the Object being locked.
1132   const int MonitorEdges = 2;
1133   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
1134   assert(req() == jvms()->endoff(), "correct sizing");
1135   int nextmon = jvms()->scloff();
1136   if (GenerateSynchronizationCode) {
1137     ins_req(nextmon,   lock->box_node());
1138     ins_req(nextmon+1, lock->obj_node());
1139   } else {
1140     Node* top = Compile::current()->top();
1141     ins_req(nextmon, top);
1142     ins_req(nextmon, top);
1143   }
1144   jvms()->set_scloff(nextmon + MonitorEdges);
1145   jvms()->set_endoff(req());
1146 }
1147 
1148 void SafePointNode::pop_monitor() {
1149   // Delete last monitor from debug info
1150   debug_only(int num_before_pop = jvms()->nof_monitors());
1151   const int MonitorEdges = 2;
1152   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
1153   int scloff = jvms()->scloff();
1154   int endoff = jvms()->endoff();
1155   int new_scloff = scloff - MonitorEdges;
1156   int new_endoff = endoff - MonitorEdges;
1157   jvms()->set_scloff(new_scloff);
1158   jvms()->set_endoff(new_endoff);
1159   while (scloff > new_scloff)  del_req_ordered(--scloff);
1160   assert(jvms()->nof_monitors() == num_before_pop-1, "");
1161 }
1162 
1163 Node *SafePointNode::peek_monitor_box() const {
1164   int mon = jvms()->nof_monitors() - 1;
1165   assert(mon >= 0, "most have a monitor");
1166   return monitor_box(jvms(), mon);
1167 }
1168 
1169 Node *SafePointNode::peek_monitor_obj() const {
1170   int mon = jvms()->nof_monitors() - 1;
1171   assert(mon >= 0, "most have a monitor");
1172   return monitor_obj(jvms(), mon);
1173 }
1174 
1175 // Do we Match on this edge index or not?  Match no edges
1176 uint SafePointNode::match_edge(uint idx) const {
1177   if( !needs_polling_address_input() )
1178     return 0;
1179 
1180   return (TypeFunc::Parms == idx);
1181 }
1182 
1183 void SafePointNode::disconnect_from_root(PhaseIterGVN *igvn) {
1184   assert(Opcode() == Op_SafePoint, "only value for safepoint in loops");
1185   int nb = igvn->C->root()->find_prec_edge(this);
1186   if (nb != -1) {
1187     igvn->C->root()->rm_prec(nb);
1188   }
1189 }
1190 
1191 //==============  SafePointScalarObjectNode  ==============
1192 
1193 SafePointScalarObjectNode::SafePointScalarObjectNode(const TypeOopPtr* tp,
1194 #ifdef ASSERT
1195                                                      AllocateNode* alloc,
1196 #endif
1197                                                      uint first_index,
1198                                                      uint n_fields) :
1199   TypeNode(tp, 1), // 1 control input -- seems required.  Get from root.
1200 #ifdef ASSERT
1201   _alloc(alloc),
1202 #endif
1203   _first_index(first_index),
1204   _n_fields(n_fields)
1205 {
1206   init_class_id(Class_SafePointScalarObject);
1207 }
1208 
1209 // Do not allow value-numbering for SafePointScalarObject node.
1210 uint SafePointScalarObjectNode::hash() const { return NO_HASH; }
1211 uint SafePointScalarObjectNode::cmp( const Node &n ) const {
1212   return (&n == this); // Always fail except on self
1213 }
1214 
1215 uint SafePointScalarObjectNode::ideal_reg() const {
1216   return 0; // No matching to machine instruction
1217 }
1218 
1219 const RegMask &SafePointScalarObjectNode::in_RegMask(uint idx) const {
1220   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
1221 }
1222 
1223 const RegMask &SafePointScalarObjectNode::out_RegMask() const {
1224   return RegMask::Empty;
1225 }
1226 
1227 uint SafePointScalarObjectNode::match_edge(uint idx) const {
1228   return 0;
1229 }
1230 
1231 SafePointScalarObjectNode*
1232 SafePointScalarObjectNode::clone(Dict* sosn_map) const {
1233   void* cached = (*sosn_map)[(void*)this];
1234   if (cached != NULL) {
1235     return (SafePointScalarObjectNode*)cached;
1236   }
1237   SafePointScalarObjectNode* res = (SafePointScalarObjectNode*)Node::clone();
1238   sosn_map->Insert((void*)this, (void*)res);
1239   return res;
1240 }
1241 
1242 
1243 #ifndef PRODUCT
1244 void SafePointScalarObjectNode::dump_spec(outputStream *st) const {
1245   st->print(" # fields@[%d..%d]", first_index(),
1246              first_index() + n_fields() - 1);
1247 }
1248 
1249 #endif
1250 
1251 //=============================================================================
1252 uint AllocateNode::size_of() const { return sizeof(*this); }
1253 
1254 AllocateNode::AllocateNode(Compile* C, const TypeFunc *atype,
1255                            Node *ctrl, Node *mem, Node *abio,
1256                            Node *size, Node *klass_node, Node *initial_test)
1257   : CallNode(atype, NULL, TypeRawPtr::BOTTOM)
1258 {
1259   init_class_id(Class_Allocate);
1260   init_flags(Flag_is_macro);
1261   _is_scalar_replaceable = false;
1262   _is_non_escaping = false;
1263   Node *topnode = C->top();
1264 
1265   init_req( TypeFunc::Control  , ctrl );
1266   init_req( TypeFunc::I_O      , abio );
1267   init_req( TypeFunc::Memory   , mem );
1268   init_req( TypeFunc::ReturnAdr, topnode );
1269   init_req( TypeFunc::FramePtr , topnode );
1270   init_req( AllocSize          , size);
1271   init_req( KlassNode          , klass_node);
1272   init_req( InitialTest        , initial_test);
1273   init_req( ALength            , topnode);
1274   C->add_macro_node(this);
1275 }
1276 
1277 //=============================================================================
1278 Node* AllocateArrayNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1279   if (remove_dead_region(phase, can_reshape))  return this;
1280   // Don't bother trying to transform a dead node
1281   if (in(0) && in(0)->is_top())  return NULL;
1282 
1283   const Type* type = phase->type(Ideal_length());
1284   if (type->isa_int() && type->is_int()->_hi < 0) {
1285     if (can_reshape) {
1286       PhaseIterGVN *igvn = phase->is_IterGVN();
1287       // Unreachable fall through path (negative array length),
1288       // the allocation can only throw so disconnect it.
1289       Node* proj = proj_out(TypeFunc::Control);
1290       Node* catchproj = NULL;
1291       if (proj != NULL) {
1292         for (DUIterator_Fast imax, i = proj->fast_outs(imax); i < imax; i++) {
1293           Node *cn = proj->fast_out(i);
1294           if (cn->is_Catch()) {
1295             catchproj = cn->as_Multi()->proj_out(CatchProjNode::fall_through_index);
1296             break;
1297           }
1298         }
1299       }
1300       if (catchproj != NULL && catchproj->outcnt() > 0 &&
1301           (catchproj->outcnt() > 1 ||
1302            catchproj->unique_out()->Opcode() != Op_Halt)) {
1303         assert(catchproj->is_CatchProj(), "must be a CatchProjNode");
1304         Node* nproj = catchproj->clone();
1305         igvn->register_new_node_with_optimizer(nproj);
1306 
1307         Node *frame = new (phase->C) ParmNode( phase->C->start(), TypeFunc::FramePtr );
1308         frame = phase->transform(frame);
1309         // Halt & Catch Fire
1310         Node *halt = new (phase->C) HaltNode( nproj, frame );
1311         phase->C->root()->add_req(halt);
1312         phase->transform(halt);
1313 
1314         igvn->replace_node(catchproj, phase->C->top());
1315         return this;
1316       }
1317     } else {
1318       // Can't correct it during regular GVN so register for IGVN
1319       phase->C->record_for_igvn(this);
1320     }
1321   }
1322   return NULL;
1323 }
1324 
1325 // Retrieve the length from the AllocateArrayNode. Narrow the type with a
1326 // CastII, if appropriate.  If we are not allowed to create new nodes, and
1327 // a CastII is appropriate, return NULL.
1328 Node *AllocateArrayNode::make_ideal_length(const TypeOopPtr* oop_type, PhaseTransform *phase, bool allow_new_nodes) {
1329   Node *length = in(AllocateNode::ALength);
1330   assert(length != NULL, "length is not null");
1331 
1332   const TypeInt* length_type = phase->find_int_type(length);
1333   const TypeAryPtr* ary_type = oop_type->isa_aryptr();
1334 
1335   if (ary_type != NULL && length_type != NULL) {
1336     const TypeInt* narrow_length_type = ary_type->narrow_size_type(length_type);
1337     if (narrow_length_type != length_type) {
1338       // Assert one of:
1339       //   - the narrow_length is 0
1340       //   - the narrow_length is not wider than length
1341       assert(narrow_length_type == TypeInt::ZERO ||
1342              length_type->is_con() && narrow_length_type->is_con() &&
1343                 (narrow_length_type->_hi <= length_type->_lo) ||
1344              (narrow_length_type->_hi <= length_type->_hi &&
1345               narrow_length_type->_lo >= length_type->_lo),
1346              "narrow type must be narrower than length type");
1347 
1348       // Return NULL if new nodes are not allowed
1349       if (!allow_new_nodes) return NULL;
1350       // Create a cast which is control dependent on the initialization to
1351       // propagate the fact that the array length must be positive.
1352       length = new (phase->C) CastIINode(length, narrow_length_type);
1353       length->set_req(0, initialization()->proj_out(0));
1354     }
1355   }
1356 
1357   return length;
1358 }
1359 
1360 //=============================================================================
1361 uint LockNode::size_of() const { return sizeof(*this); }
1362 
1363 // Redundant lock elimination
1364 //
1365 // There are various patterns of locking where we release and
1366 // immediately reacquire a lock in a piece of code where no operations
1367 // occur in between that would be observable.  In those cases we can
1368 // skip releasing and reacquiring the lock without violating any
1369 // fairness requirements.  Doing this around a loop could cause a lock
1370 // to be held for a very long time so we concentrate on non-looping
1371 // control flow.  We also require that the operations are fully
1372 // redundant meaning that we don't introduce new lock operations on
1373 // some paths so to be able to eliminate it on others ala PRE.  This
1374 // would probably require some more extensive graph manipulation to
1375 // guarantee that the memory edges were all handled correctly.
1376 //
1377 // Assuming p is a simple predicate which can't trap in any way and s
1378 // is a synchronized method consider this code:
1379 //
1380 //   s();
1381 //   if (p)
1382 //     s();
1383 //   else
1384 //     s();
1385 //   s();
1386 //
1387 // 1. The unlocks of the first call to s can be eliminated if the
1388 // locks inside the then and else branches are eliminated.
1389 //
1390 // 2. The unlocks of the then and else branches can be eliminated if
1391 // the lock of the final call to s is eliminated.
1392 //
1393 // Either of these cases subsumes the simple case of sequential control flow
1394 //
1395 // Addtionally we can eliminate versions without the else case:
1396 //
1397 //   s();
1398 //   if (p)
1399 //     s();
1400 //   s();
1401 //
1402 // 3. In this case we eliminate the unlock of the first s, the lock
1403 // and unlock in the then case and the lock in the final s.
1404 //
1405 // Note also that in all these cases the then/else pieces don't have
1406 // to be trivial as long as they begin and end with synchronization
1407 // operations.
1408 //
1409 //   s();
1410 //   if (p)
1411 //     s();
1412 //     f();
1413 //     s();
1414 //   s();
1415 //
1416 // The code will work properly for this case, leaving in the unlock
1417 // before the call to f and the relock after it.
1418 //
1419 // A potentially interesting case which isn't handled here is when the
1420 // locking is partially redundant.
1421 //
1422 //   s();
1423 //   if (p)
1424 //     s();
1425 //
1426 // This could be eliminated putting unlocking on the else case and
1427 // eliminating the first unlock and the lock in the then side.
1428 // Alternatively the unlock could be moved out of the then side so it
1429 // was after the merge and the first unlock and second lock
1430 // eliminated.  This might require less manipulation of the memory
1431 // state to get correct.
1432 //
1433 // Additionally we might allow work between a unlock and lock before
1434 // giving up eliminating the locks.  The current code disallows any
1435 // conditional control flow between these operations.  A formulation
1436 // similar to partial redundancy elimination computing the
1437 // availability of unlocking and the anticipatability of locking at a
1438 // program point would allow detection of fully redundant locking with
1439 // some amount of work in between.  I'm not sure how often I really
1440 // think that would occur though.  Most of the cases I've seen
1441 // indicate it's likely non-trivial work would occur in between.
1442 // There may be other more complicated constructs where we could
1443 // eliminate locking but I haven't seen any others appear as hot or
1444 // interesting.
1445 //
1446 // Locking and unlocking have a canonical form in ideal that looks
1447 // roughly like this:
1448 //
1449 //              <obj>
1450 //                | \\------+
1451 //                |  \       \
1452 //                | BoxLock   \
1453 //                |  |   |     \
1454 //                |  |    \     \
1455 //                |  |   FastLock
1456 //                |  |   /
1457 //                |  |  /
1458 //                |  |  |
1459 //
1460 //               Lock
1461 //                |
1462 //            Proj #0
1463 //                |
1464 //            MembarAcquire
1465 //                |
1466 //            Proj #0
1467 //
1468 //            MembarRelease
1469 //                |
1470 //            Proj #0
1471 //                |
1472 //              Unlock
1473 //                |
1474 //            Proj #0
1475 //
1476 //
1477 // This code proceeds by processing Lock nodes during PhaseIterGVN
1478 // and searching back through its control for the proper code
1479 // patterns.  Once it finds a set of lock and unlock operations to
1480 // eliminate they are marked as eliminatable which causes the
1481 // expansion of the Lock and Unlock macro nodes to make the operation a NOP
1482 //
1483 //=============================================================================
1484 
1485 //
1486 // Utility function to skip over uninteresting control nodes.  Nodes skipped are:
1487 //   - copy regions.  (These may not have been optimized away yet.)
1488 //   - eliminated locking nodes
1489 //
1490 static Node *next_control(Node *ctrl) {
1491   if (ctrl == NULL)
1492     return NULL;
1493   while (1) {
1494     if (ctrl->is_Region()) {
1495       RegionNode *r = ctrl->as_Region();
1496       Node *n = r->is_copy();
1497       if (n == NULL)
1498         break;  // hit a region, return it
1499       else
1500         ctrl = n;
1501     } else if (ctrl->is_Proj()) {
1502       Node *in0 = ctrl->in(0);
1503       if (in0->is_AbstractLock() && in0->as_AbstractLock()->is_eliminated()) {
1504         ctrl = in0->in(0);
1505       } else {
1506         break;
1507       }
1508     } else {
1509       break; // found an interesting control
1510     }
1511   }
1512   return ctrl;
1513 }
1514 //
1515 // Given a control, see if it's the control projection of an Unlock which
1516 // operating on the same object as lock.
1517 //
1518 bool AbstractLockNode::find_matching_unlock(const Node* ctrl, LockNode* lock,
1519                                             GrowableArray<AbstractLockNode*> &lock_ops) {
1520   ProjNode *ctrl_proj = (ctrl->is_Proj()) ? ctrl->as_Proj() : NULL;
1521   if (ctrl_proj != NULL && ctrl_proj->_con == TypeFunc::Control) {
1522     Node *n = ctrl_proj->in(0);
1523     if (n != NULL && n->is_Unlock()) {
1524       UnlockNode *unlock = n->as_Unlock();
1525       if (lock->obj_node()->eqv_uncast(unlock->obj_node()) &&
1526           BoxLockNode::same_slot(lock->box_node(), unlock->box_node()) &&
1527           !unlock->is_eliminated()) {
1528         lock_ops.append(unlock);
1529         return true;
1530       }
1531     }
1532   }
1533   return false;
1534 }
1535 
1536 //
1537 // Find the lock matching an unlock.  Returns null if a safepoint
1538 // or complicated control is encountered first.
1539 LockNode *AbstractLockNode::find_matching_lock(UnlockNode* unlock) {
1540   LockNode *lock_result = NULL;
1541   // find the matching lock, or an intervening safepoint
1542   Node *ctrl = next_control(unlock->in(0));
1543   while (1) {
1544     assert(ctrl != NULL, "invalid control graph");
1545     assert(!ctrl->is_Start(), "missing lock for unlock");
1546     if (ctrl->is_top()) break;  // dead control path
1547     if (ctrl->is_Proj()) ctrl = ctrl->in(0);
1548     if (ctrl->is_SafePoint()) {
1549         break;  // found a safepoint (may be the lock we are searching for)
1550     } else if (ctrl->is_Region()) {
1551       // Check for a simple diamond pattern.  Punt on anything more complicated
1552       if (ctrl->req() == 3 && ctrl->in(1) != NULL && ctrl->in(2) != NULL) {
1553         Node *in1 = next_control(ctrl->in(1));
1554         Node *in2 = next_control(ctrl->in(2));
1555         if (((in1->is_IfTrue() && in2->is_IfFalse()) ||
1556              (in2->is_IfTrue() && in1->is_IfFalse())) && (in1->in(0) == in2->in(0))) {
1557           ctrl = next_control(in1->in(0)->in(0));
1558         } else {
1559           break;
1560         }
1561       } else {
1562         break;
1563       }
1564     } else {
1565       ctrl = next_control(ctrl->in(0));  // keep searching
1566     }
1567   }
1568   if (ctrl->is_Lock()) {
1569     LockNode *lock = ctrl->as_Lock();
1570     if (lock->obj_node()->eqv_uncast(unlock->obj_node()) &&
1571         BoxLockNode::same_slot(lock->box_node(), unlock->box_node())) {
1572       lock_result = lock;
1573     }
1574   }
1575   return lock_result;
1576 }
1577 
1578 // This code corresponds to case 3 above.
1579 
1580 bool AbstractLockNode::find_lock_and_unlock_through_if(Node* node, LockNode* lock,
1581                                                        GrowableArray<AbstractLockNode*> &lock_ops) {
1582   Node* if_node = node->in(0);
1583   bool  if_true = node->is_IfTrue();
1584 
1585   if (if_node->is_If() && if_node->outcnt() == 2 && (if_true || node->is_IfFalse())) {
1586     Node *lock_ctrl = next_control(if_node->in(0));
1587     if (find_matching_unlock(lock_ctrl, lock, lock_ops)) {
1588       Node* lock1_node = NULL;
1589       ProjNode* proj = if_node->as_If()->proj_out(!if_true);
1590       if (if_true) {
1591         if (proj->is_IfFalse() && proj->outcnt() == 1) {
1592           lock1_node = proj->unique_out();
1593         }
1594       } else {
1595         if (proj->is_IfTrue() && proj->outcnt() == 1) {
1596           lock1_node = proj->unique_out();
1597         }
1598       }
1599       if (lock1_node != NULL && lock1_node->is_Lock()) {
1600         LockNode *lock1 = lock1_node->as_Lock();
1601         if (lock->obj_node()->eqv_uncast(lock1->obj_node()) &&
1602             BoxLockNode::same_slot(lock->box_node(), lock1->box_node()) &&
1603             !lock1->is_eliminated()) {
1604           lock_ops.append(lock1);
1605           return true;
1606         }
1607       }
1608     }
1609   }
1610 
1611   lock_ops.trunc_to(0);
1612   return false;
1613 }
1614 
1615 bool AbstractLockNode::find_unlocks_for_region(const RegionNode* region, LockNode* lock,
1616                                GrowableArray<AbstractLockNode*> &lock_ops) {
1617   // check each control merging at this point for a matching unlock.
1618   // in(0) should be self edge so skip it.
1619   for (int i = 1; i < (int)region->req(); i++) {
1620     Node *in_node = next_control(region->in(i));
1621     if (in_node != NULL) {
1622       if (find_matching_unlock(in_node, lock, lock_ops)) {
1623         // found a match so keep on checking.
1624         continue;
1625       } else if (find_lock_and_unlock_through_if(in_node, lock, lock_ops)) {
1626         continue;
1627       }
1628 
1629       // If we fall through to here then it was some kind of node we
1630       // don't understand or there wasn't a matching unlock, so give
1631       // up trying to merge locks.
1632       lock_ops.trunc_to(0);
1633       return false;
1634     }
1635   }
1636   return true;
1637 
1638 }
1639 
1640 #ifndef PRODUCT
1641 //
1642 // Create a counter which counts the number of times this lock is acquired
1643 //
1644 void AbstractLockNode::create_lock_counter(JVMState* state) {
1645   _counter = OptoRuntime::new_named_counter(state, NamedCounter::LockCounter);
1646 }
1647 
1648 void AbstractLockNode::set_eliminated_lock_counter() {
1649   if (_counter) {
1650     // Update the counter to indicate that this lock was eliminated.
1651     // The counter update code will stay around even though the
1652     // optimizer will eliminate the lock operation itself.
1653     _counter->set_tag(NamedCounter::EliminatedLockCounter);
1654   }
1655 }
1656 #endif
1657 
1658 //=============================================================================
1659 Node *LockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1660 
1661   // perform any generic optimizations first (returns 'this' or NULL)
1662   Node *result = SafePointNode::Ideal(phase, can_reshape);
1663   if (result != NULL)  return result;
1664   // Don't bother trying to transform a dead node
1665   if (in(0) && in(0)->is_top())  return NULL;
1666 
1667   // Now see if we can optimize away this lock.  We don't actually
1668   // remove the locking here, we simply set the _eliminate flag which
1669   // prevents macro expansion from expanding the lock.  Since we don't
1670   // modify the graph, the value returned from this function is the
1671   // one computed above.
1672   if (can_reshape && EliminateLocks && !is_non_esc_obj()) {
1673     //
1674     // If we are locking an unescaped object, the lock/unlock is unnecessary
1675     //
1676     ConnectionGraph *cgr = phase->C->congraph();
1677     if (cgr != NULL && cgr->not_global_escape(obj_node())) {
1678       assert(!is_eliminated() || is_coarsened(), "sanity");
1679       // The lock could be marked eliminated by lock coarsening
1680       // code during first IGVN before EA. Replace coarsened flag
1681       // to eliminate all associated locks/unlocks.
1682 #ifdef ASSERT
1683       this->log_lock_optimization(phase->C,"eliminate_lock_set_non_esc1");
1684 #endif
1685       this->set_non_esc_obj();
1686       return result;
1687     }
1688 
1689     //
1690     // Try lock coarsening
1691     //
1692     PhaseIterGVN* iter = phase->is_IterGVN();
1693     if (iter != NULL && !is_eliminated()) {
1694 
1695       GrowableArray<AbstractLockNode*>   lock_ops;
1696 
1697       Node *ctrl = next_control(in(0));
1698 
1699       // now search back for a matching Unlock
1700       if (find_matching_unlock(ctrl, this, lock_ops)) {
1701         // found an unlock directly preceding this lock.  This is the
1702         // case of single unlock directly control dependent on a
1703         // single lock which is the trivial version of case 1 or 2.
1704       } else if (ctrl->is_Region() ) {
1705         if (find_unlocks_for_region(ctrl->as_Region(), this, lock_ops)) {
1706         // found lock preceded by multiple unlocks along all paths
1707         // joining at this point which is case 3 in description above.
1708         }
1709       } else {
1710         // see if this lock comes from either half of an if and the
1711         // predecessors merges unlocks and the other half of the if
1712         // performs a lock.
1713         if (find_lock_and_unlock_through_if(ctrl, this, lock_ops)) {
1714           // found unlock splitting to an if with locks on both branches.
1715         }
1716       }
1717 
1718       if (lock_ops.length() > 0) {
1719         // add ourselves to the list of locks to be eliminated.
1720         lock_ops.append(this);
1721 
1722   #ifndef PRODUCT
1723         if (PrintEliminateLocks) {
1724           int locks = 0;
1725           int unlocks = 0;
1726           for (int i = 0; i < lock_ops.length(); i++) {
1727             AbstractLockNode* lock = lock_ops.at(i);
1728             if (lock->Opcode() == Op_Lock)
1729               locks++;
1730             else
1731               unlocks++;
1732             if (Verbose) {
1733               lock->dump(1);
1734             }
1735           }
1736           tty->print_cr("***Eliminated %d unlocks and %d locks", unlocks, locks);
1737         }
1738   #endif
1739 
1740         // for each of the identified locks, mark them
1741         // as eliminatable
1742         for (int i = 0; i < lock_ops.length(); i++) {
1743           AbstractLockNode* lock = lock_ops.at(i);
1744 
1745           // Mark it eliminated by coarsening and update any counters
1746 #ifdef ASSERT
1747           lock->log_lock_optimization(phase->C, "eliminate_lock_set_coarsened");
1748 #endif
1749           lock->set_coarsened();
1750         }
1751       } else if (ctrl->is_Region() &&
1752                  iter->_worklist.member(ctrl)) {
1753         // We weren't able to find any opportunities but the region this
1754         // lock is control dependent on hasn't been processed yet so put
1755         // this lock back on the worklist so we can check again once any
1756         // region simplification has occurred.
1757         iter->_worklist.push(this);
1758       }
1759     }
1760   }
1761 
1762   return result;
1763 }
1764 
1765 //=============================================================================
1766 bool LockNode::is_nested_lock_region() {
1767   return is_nested_lock_region(NULL);
1768 }
1769 
1770 // p is used for access to compilation log; no logging if NULL
1771 bool LockNode::is_nested_lock_region(Compile * c) {
1772   BoxLockNode* box = box_node()->as_BoxLock();
1773   int stk_slot = box->stack_slot();
1774   if (stk_slot <= 0) {
1775 #ifdef ASSERT
1776     this->log_lock_optimization(c, "eliminate_lock_INLR_1");
1777 #endif
1778     return false; // External lock or it is not Box (Phi node).
1779   }
1780 
1781   // Ignore complex cases: merged locks or multiple locks.
1782   Node* obj = obj_node();
1783   LockNode* unique_lock = NULL;
1784   if (!box->is_simple_lock_region(&unique_lock, obj)) {
1785 #ifdef ASSERT
1786     this->log_lock_optimization(c, "eliminate_lock_INLR_2a");
1787 #endif
1788     return false;
1789   }
1790   if (unique_lock != this) {
1791 #ifdef ASSERT
1792     this->log_lock_optimization(c, "eliminate_lock_INLR_2b");
1793 #endif
1794     return false;
1795   }
1796 
1797   // Look for external lock for the same object.
1798   SafePointNode* sfn = this->as_SafePoint();
1799   JVMState* youngest_jvms = sfn->jvms();
1800   int max_depth = youngest_jvms->depth();
1801   for (int depth = 1; depth <= max_depth; depth++) {
1802     JVMState* jvms = youngest_jvms->of_depth(depth);
1803     int num_mon  = jvms->nof_monitors();
1804     // Loop over monitors
1805     for (int idx = 0; idx < num_mon; idx++) {
1806       Node* obj_node = sfn->monitor_obj(jvms, idx);
1807       BoxLockNode* box_node = sfn->monitor_box(jvms, idx)->as_BoxLock();
1808       if ((box_node->stack_slot() < stk_slot) && obj_node->eqv_uncast(obj)) {
1809         return true;
1810       }
1811     }
1812   }
1813 #ifdef ASSERT
1814   this->log_lock_optimization(c, "eliminate_lock_INLR_3");
1815 #endif
1816   return false;
1817 }
1818 
1819 //=============================================================================
1820 uint UnlockNode::size_of() const { return sizeof(*this); }
1821 
1822 //=============================================================================
1823 Node *UnlockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1824 
1825   // perform any generic optimizations first (returns 'this' or NULL)
1826   Node *result = SafePointNode::Ideal(phase, can_reshape);
1827   if (result != NULL)  return result;
1828   // Don't bother trying to transform a dead node
1829   if (in(0) && in(0)->is_top())  return NULL;
1830 
1831   // Now see if we can optimize away this unlock.  We don't actually
1832   // remove the unlocking here, we simply set the _eliminate flag which
1833   // prevents macro expansion from expanding the unlock.  Since we don't
1834   // modify the graph, the value returned from this function is the
1835   // one computed above.
1836   // Escape state is defined after Parse phase.
1837   if (can_reshape && EliminateLocks && !is_non_esc_obj()) {
1838     //
1839     // If we are unlocking an unescaped object, the lock/unlock is unnecessary.
1840     //
1841     ConnectionGraph *cgr = phase->C->congraph();
1842     if (cgr != NULL && cgr->not_global_escape(obj_node())) {
1843       assert(!is_eliminated() || is_coarsened(), "sanity");
1844       // The lock could be marked eliminated by lock coarsening
1845       // code during first IGVN before EA. Replace coarsened flag
1846       // to eliminate all associated locks/unlocks.
1847 #ifdef ASSERT
1848       this->log_lock_optimization(phase->C, "eliminate_lock_set_non_esc2");
1849 #endif
1850       this->set_non_esc_obj();
1851     }
1852   }
1853   return result;
1854 }
1855 
1856 const char * AbstractLockNode::kind_as_string() const {
1857   return is_coarsened()   ? "coarsened" :
1858          is_nested()      ? "nested" :
1859          is_non_esc_obj() ? "non_escaping" :
1860          "?";
1861 }
1862 
1863 void AbstractLockNode::log_lock_optimization(Compile *C, const char * tag)  const {
1864   if (C == NULL) {
1865     return;
1866   }
1867   CompileLog* log = C->log();
1868   if (log != NULL) {
1869     log->begin_head("%s lock='%d' compile_id='%d' class_id='%s' kind='%s'",
1870           tag, is_Lock(), C->compile_id(),
1871           is_Unlock() ? "unlock" : is_Lock() ? "lock" : "?",
1872           kind_as_string());
1873     log->stamp();
1874     log->end_head();
1875     JVMState* p = is_Unlock() ? (as_Unlock()->dbg_jvms()) : jvms();
1876     while (p != NULL) {
1877       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1878       p = p->caller();
1879     }
1880     log->tail(tag);
1881   }
1882 }
1883