1 /*
   2  * Copyright (c) 1997, 2018, 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 "gc/shared/barrierSet.hpp"
  30 #include "gc/shared/c2/barrierSetC2.hpp"
  31 #include "interpreter/interpreter.hpp"
  32 #include "opto/callGenerator.hpp"
  33 #include "opto/callnode.hpp"
  34 #include "opto/castnode.hpp"
  35 #include "opto/convertnode.hpp"
  36 #include "opto/escape.hpp"
  37 #include "opto/locknode.hpp"
  38 #include "opto/machnode.hpp"
  39 #include "opto/matcher.hpp"
  40 #include "opto/parse.hpp"
  41 #include "opto/regalloc.hpp"
  42 #include "opto/regmask.hpp"
  43 #include "opto/rootnode.hpp"
  44 #include "opto/runtime.hpp"
  45 
  46 // Portions of code courtesy of Clifford Click
  47 
  48 // Optimization - Graph Style
  49 
  50 //=============================================================================
  51 uint StartNode::size_of() const { return sizeof(*this); }
  52 uint StartNode::cmp( const Node &n ) const
  53 { return _domain == ((StartNode&)n)._domain; }
  54 const Type *StartNode::bottom_type() const { return _domain; }
  55 const Type* StartNode::Value(PhaseGVN* phase) const { return _domain; }
  56 #ifndef PRODUCT
  57 void StartNode::dump_spec(outputStream *st) const { st->print(" #"); _domain->dump_on(st);}
  58 void StartNode::dump_compact_spec(outputStream *st) const { /* empty */ }
  59 #endif
  60 
  61 //------------------------------Ideal------------------------------------------
  62 Node *StartNode::Ideal(PhaseGVN *phase, bool can_reshape){
  63   return remove_dead_region(phase, can_reshape) ? this : NULL;
  64 }
  65 
  66 //------------------------------calling_convention-----------------------------
  67 void StartNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
  68   Matcher::calling_convention( sig_bt, parm_regs, argcnt, false );
  69 }
  70 
  71 //------------------------------Registers--------------------------------------
  72 const RegMask &StartNode::in_RegMask(uint) const {
  73   return RegMask::Empty;
  74 }
  75 
  76 //------------------------------match------------------------------------------
  77 // Construct projections for incoming parameters, and their RegMask info
  78 Node *StartNode::match( const ProjNode *proj, const Matcher *match ) {
  79   switch (proj->_con) {
  80   case TypeFunc::Control:
  81   case TypeFunc::I_O:
  82   case TypeFunc::Memory:
  83     return new MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
  84   case TypeFunc::FramePtr:
  85     return new MachProjNode(this,proj->_con,Matcher::c_frame_ptr_mask, Op_RegP);
  86   case TypeFunc::ReturnAdr:
  87     return new MachProjNode(this,proj->_con,match->_return_addr_mask,Op_RegP);
  88   case TypeFunc::Parms:
  89   default: {
  90       uint parm_num = proj->_con - TypeFunc::Parms;
  91       const Type *t = _domain->field_at(proj->_con);
  92       if (t->base() == Type::Half)  // 2nd half of Longs and Doubles
  93         return new ConNode(Type::TOP);
  94       uint ideal_reg = t->ideal_reg();
  95       RegMask &rm = match->_calling_convention_mask[parm_num];
  96       return new MachProjNode(this,proj->_con,rm,ideal_reg);
  97     }
  98   }
  99   return NULL;
 100 }
 101 
 102 //------------------------------StartOSRNode----------------------------------
 103 // The method start node for an on stack replacement adapter
 104 
 105 //------------------------------osr_domain-----------------------------
 106 const TypeTuple *StartOSRNode::osr_domain() {
 107   const Type **fields = TypeTuple::fields(2);
 108   fields[TypeFunc::Parms+0] = TypeRawPtr::BOTTOM;  // address of osr buffer
 109 
 110   return TypeTuple::make(TypeFunc::Parms+1, fields);
 111 }
 112 
 113 //=============================================================================
 114 const char * const ParmNode::names[TypeFunc::Parms+1] = {
 115   "Control", "I_O", "Memory", "FramePtr", "ReturnAdr", "Parms"
 116 };
 117 
 118 #ifndef PRODUCT
 119 void ParmNode::dump_spec(outputStream *st) const {
 120   if( _con < TypeFunc::Parms ) {
 121     st->print("%s", names[_con]);
 122   } else {
 123     st->print("Parm%d: ",_con-TypeFunc::Parms);
 124     // Verbose and WizardMode dump bottom_type for all nodes
 125     if( !Verbose && !WizardMode )   bottom_type()->dump_on(st);
 126   }
 127 }
 128 
 129 void ParmNode::dump_compact_spec(outputStream *st) const {
 130   if (_con < TypeFunc::Parms) {
 131     st->print("%s", names[_con]);
 132   } else {
 133     st->print("%d:", _con-TypeFunc::Parms);
 134     // unconditionally dump bottom_type
 135     bottom_type()->dump_on(st);
 136   }
 137 }
 138 
 139 // For a ParmNode, all immediate inputs and outputs are considered relevant
 140 // both in compact and standard representation.
 141 void ParmNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
 142   this->collect_nodes(in_rel, 1, false, false);
 143   this->collect_nodes(out_rel, -1, false, false);
 144 }
 145 #endif
 146 
 147 uint ParmNode::ideal_reg() const {
 148   switch( _con ) {
 149   case TypeFunc::Control  : // fall through
 150   case TypeFunc::I_O      : // fall through
 151   case TypeFunc::Memory   : return 0;
 152   case TypeFunc::FramePtr : // fall through
 153   case TypeFunc::ReturnAdr: return Op_RegP;
 154   default                 : assert( _con > TypeFunc::Parms, "" );
 155     // fall through
 156   case TypeFunc::Parms    : {
 157     // Type of argument being passed
 158     const Type *t = in(0)->as_Start()->_domain->field_at(_con);
 159     return t->ideal_reg();
 160   }
 161   }
 162   ShouldNotReachHere();
 163   return 0;
 164 }
 165 
 166 //=============================================================================
 167 ReturnNode::ReturnNode(uint edges, Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *retadr ) : Node(edges) {
 168   init_req(TypeFunc::Control,cntrl);
 169   init_req(TypeFunc::I_O,i_o);
 170   init_req(TypeFunc::Memory,memory);
 171   init_req(TypeFunc::FramePtr,frameptr);
 172   init_req(TypeFunc::ReturnAdr,retadr);
 173 }
 174 
 175 Node *ReturnNode::Ideal(PhaseGVN *phase, bool can_reshape){
 176   return remove_dead_region(phase, can_reshape) ? this : NULL;
 177 }
 178 
 179 const Type* ReturnNode::Value(PhaseGVN* phase) const {
 180   return ( phase->type(in(TypeFunc::Control)) == Type::TOP)
 181     ? Type::TOP
 182     : Type::BOTTOM;
 183 }
 184 
 185 // Do we Match on this edge index or not?  No edges on return nodes
 186 uint ReturnNode::match_edge(uint idx) const {
 187   return 0;
 188 }
 189 
 190 
 191 #ifndef PRODUCT
 192 void ReturnNode::dump_req(outputStream *st) const {
 193   // Dump the required inputs, enclosed in '(' and ')'
 194   uint i;                       // Exit value of loop
 195   for (i = 0; i < req(); i++) {    // For all required inputs
 196     if (i == TypeFunc::Parms) st->print("returns");
 197     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 198     else st->print("_ ");
 199   }
 200 }
 201 #endif
 202 
 203 //=============================================================================
 204 RethrowNode::RethrowNode(
 205   Node* cntrl,
 206   Node* i_o,
 207   Node* memory,
 208   Node* frameptr,
 209   Node* ret_adr,
 210   Node* exception
 211 ) : Node(TypeFunc::Parms + 1) {
 212   init_req(TypeFunc::Control  , cntrl    );
 213   init_req(TypeFunc::I_O      , i_o      );
 214   init_req(TypeFunc::Memory   , memory   );
 215   init_req(TypeFunc::FramePtr , frameptr );
 216   init_req(TypeFunc::ReturnAdr, ret_adr);
 217   init_req(TypeFunc::Parms    , exception);
 218 }
 219 
 220 Node *RethrowNode::Ideal(PhaseGVN *phase, bool can_reshape){
 221   return remove_dead_region(phase, can_reshape) ? this : NULL;
 222 }
 223 
 224 const Type* RethrowNode::Value(PhaseGVN* phase) const {
 225   return (phase->type(in(TypeFunc::Control)) == Type::TOP)
 226     ? Type::TOP
 227     : Type::BOTTOM;
 228 }
 229 
 230 uint RethrowNode::match_edge(uint idx) const {
 231   return 0;
 232 }
 233 
 234 #ifndef PRODUCT
 235 void RethrowNode::dump_req(outputStream *st) const {
 236   // Dump the required inputs, enclosed in '(' and ')'
 237   uint i;                       // Exit value of loop
 238   for (i = 0; i < req(); i++) {    // For all required inputs
 239     if (i == TypeFunc::Parms) st->print("exception");
 240     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 241     else st->print("_ ");
 242   }
 243 }
 244 #endif
 245 
 246 //=============================================================================
 247 // Do we Match on this edge index or not?  Match only target address & method
 248 uint TailCallNode::match_edge(uint idx) const {
 249   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 250 }
 251 
 252 //=============================================================================
 253 // Do we Match on this edge index or not?  Match only target address & oop
 254 uint TailJumpNode::match_edge(uint idx) const {
 255   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 256 }
 257 
 258 //=============================================================================
 259 JVMState::JVMState(ciMethod* method, JVMState* caller) :
 260   _method(method) {
 261   assert(method != NULL, "must be valid call site");
 262   _bci = InvocationEntryBci;
 263   _reexecute = Reexecute_Undefined;
 264   debug_only(_bci = -99);  // random garbage value
 265   debug_only(_map = (SafePointNode*)-1);
 266   _caller = caller;
 267   _depth  = 1 + (caller == NULL ? 0 : caller->depth());
 268   _locoff = TypeFunc::Parms;
 269   _stkoff = _locoff + _method->max_locals();
 270   _monoff = _stkoff + _method->max_stack();
 271   _scloff = _monoff;
 272   _endoff = _monoff;
 273   _sp = 0;
 274 }
 275 JVMState::JVMState(int stack_size) :
 276   _method(NULL) {
 277   _bci = InvocationEntryBci;
 278   _reexecute = Reexecute_Undefined;
 279   debug_only(_map = (SafePointNode*)-1);
 280   _caller = NULL;
 281   _depth  = 1;
 282   _locoff = TypeFunc::Parms;
 283   _stkoff = _locoff;
 284   _monoff = _stkoff + stack_size;
 285   _scloff = _monoff;
 286   _endoff = _monoff;
 287   _sp = 0;
 288 }
 289 
 290 //--------------------------------of_depth-------------------------------------
 291 JVMState* JVMState::of_depth(int d) const {
 292   const JVMState* jvmp = this;
 293   assert(0 < d && (uint)d <= depth(), "oob");
 294   for (int skip = depth() - d; skip > 0; skip--) {
 295     jvmp = jvmp->caller();
 296   }
 297   assert(jvmp->depth() == (uint)d, "found the right one");
 298   return (JVMState*)jvmp;
 299 }
 300 
 301 //-----------------------------same_calls_as-----------------------------------
 302 bool JVMState::same_calls_as(const JVMState* that) const {
 303   if (this == that)                    return true;
 304   if (this->depth() != that->depth())  return false;
 305   const JVMState* p = this;
 306   const JVMState* q = that;
 307   for (;;) {
 308     if (p->_method != q->_method)    return false;
 309     if (p->_method == NULL)          return true;   // bci is irrelevant
 310     if (p->_bci    != q->_bci)       return false;
 311     if (p->_reexecute != q->_reexecute)  return false;
 312     p = p->caller();
 313     q = q->caller();
 314     if (p == q)                      return true;
 315     assert(p != NULL && q != NULL, "depth check ensures we don't run off end");
 316   }
 317 }
 318 
 319 //------------------------------debug_start------------------------------------
 320 uint JVMState::debug_start()  const {
 321   debug_only(JVMState* jvmroot = of_depth(1));
 322   assert(jvmroot->locoff() <= this->locoff(), "youngest JVMState must be last");
 323   return of_depth(1)->locoff();
 324 }
 325 
 326 //-------------------------------debug_end-------------------------------------
 327 uint JVMState::debug_end() const {
 328   debug_only(JVMState* jvmroot = of_depth(1));
 329   assert(jvmroot->endoff() <= this->endoff(), "youngest JVMState must be last");
 330   return endoff();
 331 }
 332 
 333 //------------------------------debug_depth------------------------------------
 334 uint JVMState::debug_depth() const {
 335   uint total = 0;
 336   for (const JVMState* jvmp = this; jvmp != NULL; jvmp = jvmp->caller()) {
 337     total += jvmp->debug_size();
 338   }
 339   return total;
 340 }
 341 
 342 #ifndef PRODUCT
 343 
 344 //------------------------------format_helper----------------------------------
 345 // Given an allocation (a Chaitin object) and a Node decide if the Node carries
 346 // any defined value or not.  If it does, print out the register or constant.
 347 static void format_helper( PhaseRegAlloc *regalloc, outputStream* st, Node *n, const char *msg, uint i, GrowableArray<SafePointScalarObjectNode*> *scobjs ) {
 348   if (n == NULL) { st->print(" NULL"); return; }
 349   if (n->is_SafePointScalarObject()) {
 350     // Scalar replacement.
 351     SafePointScalarObjectNode* spobj = n->as_SafePointScalarObject();
 352     scobjs->append_if_missing(spobj);
 353     int sco_n = scobjs->find(spobj);
 354     assert(sco_n >= 0, "");
 355     st->print(" %s%d]=#ScObj" INT32_FORMAT, msg, i, sco_n);
 356     return;
 357   }
 358   if (regalloc->node_regs_max_index() > 0 &&
 359       OptoReg::is_valid(regalloc->get_reg_first(n))) { // Check for undefined
 360     char buf[50];
 361     regalloc->dump_register(n,buf);
 362     st->print(" %s%d]=%s",msg,i,buf);
 363   } else {                      // No register, but might be constant
 364     const Type *t = n->bottom_type();
 365     switch (t->base()) {
 366     case Type::Int:
 367       st->print(" %s%d]=#" INT32_FORMAT,msg,i,t->is_int()->get_con());
 368       break;
 369     case Type::AnyPtr:
 370       assert( t == TypePtr::NULL_PTR || n->in_dump(), "" );
 371       st->print(" %s%d]=#NULL",msg,i);
 372       break;
 373     case Type::AryPtr:
 374     case Type::InstPtr:
 375       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->isa_oopptr()->const_oop()));
 376       break;
 377     case Type::KlassPtr:
 378       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_klassptr()->klass()));
 379       break;
 380     case Type::MetadataPtr:
 381       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_metadataptr()->metadata()));
 382       break;
 383     case Type::NarrowOop:
 384       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_oopptr()->const_oop()));
 385       break;
 386     case Type::RawPtr:
 387       st->print(" %s%d]=#Raw" INTPTR_FORMAT,msg,i,p2i(t->is_rawptr()));
 388       break;
 389     case Type::DoubleCon:
 390       st->print(" %s%d]=#%fD",msg,i,t->is_double_constant()->_d);
 391       break;
 392     case Type::FloatCon:
 393       st->print(" %s%d]=#%fF",msg,i,t->is_float_constant()->_f);
 394       break;
 395     case Type::Long:
 396       st->print(" %s%d]=#" INT64_FORMAT,msg,i,(int64_t)(t->is_long()->get_con()));
 397       break;
 398     case Type::Half:
 399     case Type::Top:
 400       st->print(" %s%d]=_",msg,i);
 401       break;
 402     default: ShouldNotReachHere();
 403     }
 404   }
 405 }
 406 
 407 //------------------------------format-----------------------------------------
 408 void JVMState::format(PhaseRegAlloc *regalloc, const Node *n, outputStream* st) const {
 409   st->print("        #");
 410   if (_method) {
 411     _method->print_short_name(st);
 412     st->print(" @ bci:%d ",_bci);
 413   } else {
 414     st->print_cr(" runtime stub ");
 415     return;
 416   }
 417   if (n->is_MachSafePoint()) {
 418     GrowableArray<SafePointScalarObjectNode*> scobjs;
 419     MachSafePointNode *mcall = n->as_MachSafePoint();
 420     uint i;
 421     // Print locals
 422     for (i = 0; i < (uint)loc_size(); i++)
 423       format_helper(regalloc, st, mcall->local(this, i), "L[", i, &scobjs);
 424     // Print stack
 425     for (i = 0; i < (uint)stk_size(); i++) {
 426       if ((uint)(_stkoff + i) >= mcall->len())
 427         st->print(" oob ");
 428       else
 429        format_helper(regalloc, st, mcall->stack(this, i), "STK[", i, &scobjs);
 430     }
 431     for (i = 0; (int)i < nof_monitors(); i++) {
 432       Node *box = mcall->monitor_box(this, i);
 433       Node *obj = mcall->monitor_obj(this, i);
 434       if (regalloc->node_regs_max_index() > 0 &&
 435           OptoReg::is_valid(regalloc->get_reg_first(box))) {
 436         box = BoxLockNode::box_node(box);
 437         format_helper(regalloc, st, box, "MON-BOX[", i, &scobjs);
 438       } else {
 439         OptoReg::Name box_reg = BoxLockNode::reg(box);
 440         st->print(" MON-BOX%d=%s+%d",
 441                    i,
 442                    OptoReg::regname(OptoReg::c_frame_pointer),
 443                    regalloc->reg2offset(box_reg));
 444       }
 445       const char* obj_msg = "MON-OBJ[";
 446       if (EliminateLocks) {
 447         if (BoxLockNode::box_node(box)->is_eliminated())
 448           obj_msg = "MON-OBJ(LOCK ELIMINATED)[";
 449       }
 450       format_helper(regalloc, st, obj, obj_msg, i, &scobjs);
 451     }
 452 
 453     for (i = 0; i < (uint)scobjs.length(); i++) {
 454       // Scalar replaced objects.
 455       st->cr();
 456       st->print("        # ScObj" INT32_FORMAT " ", i);
 457       SafePointScalarObjectNode* spobj = scobjs.at(i);
 458       ciKlass* cik = spobj->bottom_type()->is_oopptr()->klass();
 459       assert(cik->is_instance_klass() ||
 460              cik->is_array_klass(), "Not supported allocation.");
 461       ciInstanceKlass *iklass = NULL;
 462       if (cik->is_instance_klass()) {
 463         cik->print_name_on(st);
 464         iklass = cik->as_instance_klass();
 465       } else if (cik->is_type_array_klass()) {
 466         cik->as_array_klass()->base_element_type()->print_name_on(st);
 467         st->print("[%d]", spobj->n_fields());
 468       } else if (cik->is_obj_array_klass()) {
 469         ciKlass* cie = cik->as_obj_array_klass()->base_element_klass();
 470         if (cie->is_instance_klass()) {
 471           cie->print_name_on(st);
 472         } else if (cie->is_type_array_klass()) {
 473           cie->as_array_klass()->base_element_type()->print_name_on(st);
 474         } else {
 475           ShouldNotReachHere();
 476         }
 477         st->print("[%d]", spobj->n_fields());
 478         int ndim = cik->as_array_klass()->dimension() - 1;
 479         while (ndim-- > 0) {
 480           st->print("[]");
 481         }
 482       }
 483       st->print("={");
 484       uint nf = spobj->n_fields();
 485       if (nf > 0) {
 486         uint first_ind = spobj->first_index(mcall->jvms());
 487         Node* fld_node = mcall->in(first_ind);
 488         ciField* cifield;
 489         if (iklass != NULL) {
 490           st->print(" [");
 491           cifield = iklass->nonstatic_field_at(0);
 492           cifield->print_name_on(st);
 493           format_helper(regalloc, st, fld_node, ":", 0, &scobjs);
 494         } else {
 495           format_helper(regalloc, st, fld_node, "[", 0, &scobjs);
 496         }
 497         for (uint j = 1; j < nf; j++) {
 498           fld_node = mcall->in(first_ind+j);
 499           if (iklass != NULL) {
 500             st->print(", [");
 501             cifield = iklass->nonstatic_field_at(j);
 502             cifield->print_name_on(st);
 503             format_helper(regalloc, st, fld_node, ":", j, &scobjs);
 504           } else {
 505             format_helper(regalloc, st, fld_node, ", [", j, &scobjs);
 506           }
 507         }
 508       }
 509       st->print(" }");
 510     }
 511   }
 512   st->cr();
 513   if (caller() != NULL) caller()->format(regalloc, n, st);
 514 }
 515 
 516 
 517 void JVMState::dump_spec(outputStream *st) const {
 518   if (_method != NULL) {
 519     bool printed = false;
 520     if (!Verbose) {
 521       // The JVMS dumps make really, really long lines.
 522       // Take out the most boring parts, which are the package prefixes.
 523       char buf[500];
 524       stringStream namest(buf, sizeof(buf));
 525       _method->print_short_name(&namest);
 526       if (namest.count() < sizeof(buf)) {
 527         const char* name = namest.base();
 528         if (name[0] == ' ')  ++name;
 529         const char* endcn = strchr(name, ':');  // end of class name
 530         if (endcn == NULL)  endcn = strchr(name, '(');
 531         if (endcn == NULL)  endcn = name + strlen(name);
 532         while (endcn > name && endcn[-1] != '.' && endcn[-1] != '/')
 533           --endcn;
 534         st->print(" %s", endcn);
 535         printed = true;
 536       }
 537     }
 538     if (!printed)
 539       _method->print_short_name(st);
 540     st->print(" @ bci:%d",_bci);
 541     if(_reexecute == Reexecute_True)
 542       st->print(" reexecute");
 543   } else {
 544     st->print(" runtime stub");
 545   }
 546   if (caller() != NULL)  caller()->dump_spec(st);
 547 }
 548 
 549 
 550 void JVMState::dump_on(outputStream* st) const {
 551   bool print_map = _map && !((uintptr_t)_map & 1) &&
 552                   ((caller() == NULL) || (caller()->map() != _map));
 553   if (print_map) {
 554     if (_map->len() > _map->req()) {  // _map->has_exceptions()
 555       Node* ex = _map->in(_map->req());  // _map->next_exception()
 556       // skip the first one; it's already being printed
 557       while (ex != NULL && ex->len() > ex->req()) {
 558         ex = ex->in(ex->req());  // ex->next_exception()
 559         ex->dump(1);
 560       }
 561     }
 562     _map->dump(Verbose ? 2 : 1);
 563   }
 564   if (caller() != NULL) {
 565     caller()->dump_on(st);
 566   }
 567   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=",
 568              depth(), locoff(), stkoff(), argoff(), monoff(), scloff(), endoff(), monitor_depth(), sp(), bci(), should_reexecute()?"true":"false");
 569   if (_method == NULL) {
 570     st->print_cr("(none)");
 571   } else {
 572     _method->print_name(st);
 573     st->cr();
 574     if (bci() >= 0 && bci() < _method->code_size()) {
 575       st->print("    bc: ");
 576       _method->print_codes_on(bci(), bci()+1, st);
 577     }
 578   }
 579 }
 580 
 581 // Extra way to dump a jvms from the debugger,
 582 // to avoid a bug with C++ member function calls.
 583 void dump_jvms(JVMState* jvms) {
 584   jvms->dump();
 585 }
 586 #endif
 587 
 588 //--------------------------clone_shallow--------------------------------------
 589 JVMState* JVMState::clone_shallow(Compile* C) const {
 590   JVMState* n = has_method() ? new (C) JVMState(_method, _caller) : new (C) JVMState(0);
 591   n->set_bci(_bci);
 592   n->_reexecute = _reexecute;
 593   n->set_locoff(_locoff);
 594   n->set_stkoff(_stkoff);
 595   n->set_monoff(_monoff);
 596   n->set_scloff(_scloff);
 597   n->set_endoff(_endoff);
 598   n->set_sp(_sp);
 599   n->set_map(_map);
 600   return n;
 601 }
 602 
 603 //---------------------------clone_deep----------------------------------------
 604 JVMState* JVMState::clone_deep(Compile* C) const {
 605   JVMState* n = clone_shallow(C);
 606   for (JVMState* p = n; p->_caller != NULL; p = p->_caller) {
 607     p->_caller = p->_caller->clone_shallow(C);
 608   }
 609   assert(n->depth() == depth(), "sanity");
 610   assert(n->debug_depth() == debug_depth(), "sanity");
 611   return n;
 612 }
 613 
 614 /**
 615  * Reset map for all callers
 616  */
 617 void JVMState::set_map_deep(SafePointNode* map) {
 618   for (JVMState* p = this; p->_caller != NULL; p = p->_caller) {
 619     p->set_map(map);
 620   }
 621 }
 622 
 623 // Adapt offsets in in-array after adding or removing an edge.
 624 // Prerequisite is that the JVMState is used by only one node.
 625 void JVMState::adapt_position(int delta) {
 626   for (JVMState* jvms = this; jvms != NULL; jvms = jvms->caller()) {
 627     jvms->set_locoff(jvms->locoff() + delta);
 628     jvms->set_stkoff(jvms->stkoff() + delta);
 629     jvms->set_monoff(jvms->monoff() + delta);
 630     jvms->set_scloff(jvms->scloff() + delta);
 631     jvms->set_endoff(jvms->endoff() + delta);
 632   }
 633 }
 634 
 635 // Mirror the stack size calculation in the deopt code
 636 // How much stack space would we need at this point in the program in
 637 // case of deoptimization?
 638 int JVMState::interpreter_frame_size() const {
 639   const JVMState* jvms = this;
 640   int size = 0;
 641   int callee_parameters = 0;
 642   int callee_locals = 0;
 643   int extra_args = method()->max_stack() - stk_size();
 644 
 645   while (jvms != NULL) {
 646     int locks = jvms->nof_monitors();
 647     int temps = jvms->stk_size();
 648     bool is_top_frame = (jvms == this);
 649     ciMethod* method = jvms->method();
 650 
 651     int frame_size = BytesPerWord * Interpreter::size_activation(method->max_stack(),
 652                                                                  temps + callee_parameters,
 653                                                                  extra_args,
 654                                                                  locks,
 655                                                                  callee_parameters,
 656                                                                  callee_locals,
 657                                                                  is_top_frame);
 658     size += frame_size;
 659 
 660     callee_parameters = method->size_of_parameters();
 661     callee_locals = method->max_locals();
 662     extra_args = 0;
 663     jvms = jvms->caller();
 664   }
 665   return size + Deoptimization::last_frame_adjust(0, callee_locals) * BytesPerWord;
 666 }
 667 
 668 //=============================================================================
 669 uint CallNode::cmp( const Node &n ) const
 670 { return _tf == ((CallNode&)n)._tf && _jvms == ((CallNode&)n)._jvms; }
 671 #ifndef PRODUCT
 672 void CallNode::dump_req(outputStream *st) const {
 673   // Dump the required inputs, enclosed in '(' and ')'
 674   uint i;                       // Exit value of loop
 675   for (i = 0; i < req(); i++) {    // For all required inputs
 676     if (i == TypeFunc::Parms) st->print("(");
 677     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 678     else st->print("_ ");
 679   }
 680   st->print(")");
 681 }
 682 
 683 void CallNode::dump_spec(outputStream *st) const {
 684   st->print(" ");
 685   if (tf() != NULL)  tf()->dump_on(st);
 686   if (_cnt != COUNT_UNKNOWN)  st->print(" C=%f",_cnt);
 687   if (jvms() != NULL)  jvms()->dump_spec(st);
 688 }
 689 #endif
 690 
 691 const Type *CallNode::bottom_type() const { return tf()->range(); }
 692 const Type* CallNode::Value(PhaseGVN* phase) const {
 693   if (phase->type(in(0)) == Type::TOP)  return Type::TOP;
 694   return tf()->range();
 695 }
 696 
 697 //------------------------------calling_convention-----------------------------
 698 void CallNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
 699   // Use the standard compiler calling convention
 700   Matcher::calling_convention( sig_bt, parm_regs, argcnt, true );
 701 }
 702 
 703 
 704 //------------------------------match------------------------------------------
 705 // Construct projections for control, I/O, memory-fields, ..., and
 706 // return result(s) along with their RegMask info
 707 Node *CallNode::match( const ProjNode *proj, const Matcher *match ) {
 708   switch (proj->_con) {
 709   case TypeFunc::Control:
 710   case TypeFunc::I_O:
 711   case TypeFunc::Memory:
 712     return new MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
 713 
 714   case TypeFunc::Parms+1:       // For LONG & DOUBLE returns
 715     assert(tf()->range()->field_at(TypeFunc::Parms+1) == Type::HALF, "");
 716     // 2nd half of doubles and longs
 717     return new MachProjNode(this,proj->_con, RegMask::Empty, (uint)OptoReg::Bad);
 718 
 719   case TypeFunc::Parms: {       // Normal returns
 720     uint ideal_reg = tf()->range()->field_at(TypeFunc::Parms)->ideal_reg();
 721     OptoRegPair regs = is_CallRuntime()
 722       ? match->c_return_value(ideal_reg,true)  // Calls into C runtime
 723       : match->  return_value(ideal_reg,true); // Calls into compiled Java code
 724     RegMask rm = RegMask(regs.first());
 725     if( OptoReg::is_valid(regs.second()) )
 726       rm.Insert( regs.second() );
 727     return new MachProjNode(this,proj->_con,rm,ideal_reg);
 728   }
 729 
 730   case TypeFunc::ReturnAdr:
 731   case TypeFunc::FramePtr:
 732   default:
 733     ShouldNotReachHere();
 734   }
 735   return NULL;
 736 }
 737 
 738 // Do we Match on this edge index or not?  Match no edges
 739 uint CallNode::match_edge(uint idx) const {
 740   return 0;
 741 }
 742 
 743 //
 744 // Determine whether the call could modify the field of the specified
 745 // instance at the specified offset.
 746 //
 747 bool CallNode::may_modify(const TypeOopPtr *t_oop, PhaseTransform *phase) {
 748   assert((t_oop != NULL), "sanity");
 749   if (is_call_to_arraycopystub() && strcmp(_name, "unsafe_arraycopy") != 0) {
 750     const TypeTuple* args = _tf->domain();
 751     Node* dest = NULL;
 752     // Stubs that can be called once an ArrayCopyNode is expanded have
 753     // different signatures. Look for the second pointer argument,
 754     // that is the destination of the copy.
 755     for (uint i = TypeFunc::Parms, j = 0; i < args->cnt(); i++) {
 756       if (args->field_at(i)->isa_ptr()) {
 757         j++;
 758         if (j == 2) {
 759           dest = in(i);
 760           break;
 761         }
 762       }
 763     }
 764     guarantee(dest != NULL, "Call had only one ptr in, broken IR!");
 765     if (!dest->is_top() && may_modify_arraycopy_helper(phase->type(dest)->is_oopptr(), t_oop, phase)) {
 766       return true;
 767     }
 768     return false;
 769   }
 770   if (t_oop->is_known_instance()) {
 771     // The instance_id is set only for scalar-replaceable allocations which
 772     // are not passed as arguments according to Escape Analysis.
 773     return false;
 774   }
 775   if (t_oop->is_ptr_to_boxed_value()) {
 776     ciKlass* boxing_klass = t_oop->klass();
 777     if (is_CallStaticJava() && as_CallStaticJava()->is_boxing_method()) {
 778       // Skip unrelated boxing methods.
 779       Node* proj = proj_out_or_null(TypeFunc::Parms);
 780       if ((proj == NULL) || (phase->type(proj)->is_instptr()->klass() != boxing_klass)) {
 781         return false;
 782       }
 783     }
 784     if (is_CallJava() && as_CallJava()->method() != NULL) {
 785       ciMethod* meth = as_CallJava()->method();
 786       if (meth->is_getter()) {
 787         return false;
 788       }
 789       // May modify (by reflection) if an boxing object is passed
 790       // as argument or returned.
 791       Node* proj = returns_pointer() ? proj_out_or_null(TypeFunc::Parms) : NULL;
 792       if (proj != NULL) {
 793         const TypeInstPtr* inst_t = phase->type(proj)->isa_instptr();
 794         if ((inst_t != NULL) && (!inst_t->klass_is_exact() ||
 795                                  (inst_t->klass() == boxing_klass))) {
 796           return true;
 797         }
 798       }
 799       const TypeTuple* d = tf()->domain();
 800       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 801         const TypeInstPtr* inst_t = d->field_at(i)->isa_instptr();
 802         if ((inst_t != NULL) && (!inst_t->klass_is_exact() ||
 803                                  (inst_t->klass() == boxing_klass))) {
 804           return true;
 805         }
 806       }
 807       return false;
 808     }
 809   }
 810   return true;
 811 }
 812 
 813 // Does this call have a direct reference to n other than debug information?
 814 bool CallNode::has_non_debug_use(Node *n) {
 815   const TypeTuple * d = tf()->domain();
 816   for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 817     Node *arg = in(i);
 818     if (arg == n) {
 819       return true;
 820     }
 821   }
 822   return false;
 823 }
 824 
 825 // Returns the unique CheckCastPP of a call
 826 // or 'this' if there are several CheckCastPP or unexpected uses
 827 // or returns NULL if there is no one.
 828 Node *CallNode::result_cast() {
 829   Node *cast = NULL;
 830 
 831   Node *p = proj_out_or_null(TypeFunc::Parms);
 832   if (p == NULL)
 833     return NULL;
 834 
 835   for (DUIterator_Fast imax, i = p->fast_outs(imax); i < imax; i++) {
 836     Node *use = p->fast_out(i);
 837     if (use->is_CheckCastPP()) {
 838       if (cast != NULL) {
 839         return this;  // more than 1 CheckCastPP
 840       }
 841       cast = use;
 842     } else if (!use->is_Initialize() &&
 843                !use->is_AddP() &&
 844                use->Opcode() != Op_MemBarStoreStore) {
 845       // Expected uses are restricted to a CheckCastPP, an Initialize
 846       // node, a MemBarStoreStore (clone) and AddP nodes. If we
 847       // encounter any other use (a Phi node can be seen in rare
 848       // cases) return this to prevent incorrect optimizations.
 849       return this;
 850     }
 851   }
 852   return cast;
 853 }
 854 
 855 
 856 void CallNode::extract_projections(CallProjections* projs, bool separate_io_proj, bool do_asserts) {
 857   projs->fallthrough_proj      = NULL;
 858   projs->fallthrough_catchproj = NULL;
 859   projs->fallthrough_ioproj    = NULL;
 860   projs->catchall_ioproj       = NULL;
 861   projs->catchall_catchproj    = NULL;
 862   projs->fallthrough_memproj   = NULL;
 863   projs->catchall_memproj      = NULL;
 864   projs->resproj               = NULL;
 865   projs->exobj                 = NULL;
 866 
 867   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 868     ProjNode *pn = fast_out(i)->as_Proj();
 869     if (pn->outcnt() == 0) continue;
 870     switch (pn->_con) {
 871     case TypeFunc::Control:
 872       {
 873         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 874         projs->fallthrough_proj = pn;
 875         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 876         const Node *cn = pn->fast_out(j);
 877         if (cn->is_Catch()) {
 878           ProjNode *cpn = NULL;
 879           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 880             cpn = cn->fast_out(k)->as_Proj();
 881             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 882             if (cpn->_con == CatchProjNode::fall_through_index)
 883               projs->fallthrough_catchproj = cpn;
 884             else {
 885               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 886               projs->catchall_catchproj = cpn;
 887             }
 888           }
 889         }
 890         break;
 891       }
 892     case TypeFunc::I_O:
 893       if (pn->_is_io_use)
 894         projs->catchall_ioproj = pn;
 895       else
 896         projs->fallthrough_ioproj = pn;
 897       for (DUIterator j = pn->outs(); pn->has_out(j); j++) {
 898         Node* e = pn->out(j);
 899         if (e->Opcode() == Op_CreateEx && e->in(0)->is_CatchProj() && e->outcnt() > 0) {
 900           assert(projs->exobj == NULL, "only one");
 901           projs->exobj = e;
 902         }
 903       }
 904       break;
 905     case TypeFunc::Memory:
 906       if (pn->_is_io_use)
 907         projs->catchall_memproj = pn;
 908       else
 909         projs->fallthrough_memproj = pn;
 910       break;
 911     case TypeFunc::Parms:
 912       projs->resproj = pn;
 913       break;
 914     default:
 915       assert(false, "unexpected projection from allocation node.");
 916     }
 917   }
 918 
 919   // The resproj may not exist because the result could be ignored
 920   // and the exception object may not exist if an exception handler
 921   // swallows the exception but all the other must exist and be found.
 922   assert(projs->fallthrough_proj      != NULL, "must be found");
 923   do_asserts = do_asserts && !Compile::current()->inlining_incrementally();
 924   assert(!do_asserts || projs->fallthrough_catchproj != NULL, "must be found");
 925   assert(!do_asserts || projs->fallthrough_memproj   != NULL, "must be found");
 926   assert(!do_asserts || projs->fallthrough_ioproj    != NULL, "must be found");
 927   assert(!do_asserts || projs->catchall_catchproj    != NULL, "must be found");
 928   if (separate_io_proj) {
 929     assert(!do_asserts || projs->catchall_memproj    != NULL, "must be found");
 930     assert(!do_asserts || projs->catchall_ioproj     != NULL, "must be found");
 931   }
 932 }
 933 
 934 Node *CallNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 935   CallGenerator* cg = generator();
 936   if (can_reshape && cg != NULL && cg->is_mh_late_inline() && !cg->already_attempted()) {
 937     // Check whether this MH handle call becomes a candidate for inlining
 938     ciMethod* callee = cg->method();
 939     vmIntrinsics::ID iid = callee->intrinsic_id();
 940     if (iid == vmIntrinsics::_invokeBasic) {
 941       if (in(TypeFunc::Parms)->Opcode() == Op_ConP) {
 942         phase->C->prepend_late_inline(cg);
 943         set_generator(NULL);
 944       }
 945     } else {
 946       assert(callee->has_member_arg(), "wrong type of call?");
 947       if (in(TypeFunc::Parms + callee->arg_size() - 1)->Opcode() == Op_ConP) {
 948         phase->C->prepend_late_inline(cg);
 949         set_generator(NULL);
 950       }
 951     }
 952   }
 953   return SafePointNode::Ideal(phase, can_reshape);
 954 }
 955 
 956 bool CallNode::is_call_to_arraycopystub() const {
 957   if (_name != NULL && strstr(_name, "arraycopy") != 0) {
 958     return true;
 959   }
 960   return false;
 961 }
 962 
 963 //=============================================================================
 964 uint CallJavaNode::size_of() const { return sizeof(*this); }
 965 uint CallJavaNode::cmp( const Node &n ) const {
 966   CallJavaNode &call = (CallJavaNode&)n;
 967   return CallNode::cmp(call) && _method == call._method &&
 968          _override_symbolic_info == call._override_symbolic_info;
 969 }
 970 #ifndef PRODUCT
 971 void CallJavaNode::dump_spec(outputStream *st) const {
 972   if( _method ) _method->print_short_name(st);
 973   CallNode::dump_spec(st);
 974 }
 975 
 976 void CallJavaNode::dump_compact_spec(outputStream* st) const {
 977   if (_method) {
 978     _method->print_short_name(st);
 979   } else {
 980     st->print("<?>");
 981   }
 982 }
 983 #endif
 984 
 985 //=============================================================================
 986 uint CallStaticJavaNode::size_of() const { return sizeof(*this); }
 987 uint CallStaticJavaNode::cmp( const Node &n ) const {
 988   CallStaticJavaNode &call = (CallStaticJavaNode&)n;
 989   return CallJavaNode::cmp(call);
 990 }
 991 
 992 //----------------------------uncommon_trap_request----------------------------
 993 // If this is an uncommon trap, return the request code, else zero.
 994 int CallStaticJavaNode::uncommon_trap_request() const {
 995   if (_name != NULL && !strcmp(_name, "uncommon_trap")) {
 996     return extract_uncommon_trap_request(this);
 997   }
 998   return 0;
 999 }
1000 int CallStaticJavaNode::extract_uncommon_trap_request(const Node* call) {
1001 #ifndef PRODUCT
1002   if (!(call->req() > TypeFunc::Parms &&
1003         call->in(TypeFunc::Parms) != NULL &&
1004         call->in(TypeFunc::Parms)->is_Con() &&
1005         call->in(TypeFunc::Parms)->bottom_type()->isa_int())) {
1006     assert(in_dump() != 0, "OK if dumping");
1007     tty->print("[bad uncommon trap]");
1008     return 0;
1009   }
1010 #endif
1011   return call->in(TypeFunc::Parms)->bottom_type()->is_int()->get_con();
1012 }
1013 
1014 #ifndef PRODUCT
1015 void CallStaticJavaNode::dump_spec(outputStream *st) const {
1016   st->print("# Static ");
1017   if (_name != NULL) {
1018     st->print("%s", _name);
1019     int trap_req = uncommon_trap_request();
1020     if (trap_req != 0) {
1021       char buf[100];
1022       st->print("(%s)",
1023                  Deoptimization::format_trap_request(buf, sizeof(buf),
1024                                                      trap_req));
1025     }
1026     st->print(" ");
1027   }
1028   CallJavaNode::dump_spec(st);
1029 }
1030 
1031 void CallStaticJavaNode::dump_compact_spec(outputStream* st) const {
1032   if (_method) {
1033     _method->print_short_name(st);
1034   } else if (_name) {
1035     st->print("%s", _name);
1036   } else {
1037     st->print("<?>");
1038   }
1039 }
1040 #endif
1041 
1042 //=============================================================================
1043 uint CallDynamicJavaNode::size_of() const { return sizeof(*this); }
1044 uint CallDynamicJavaNode::cmp( const Node &n ) const {
1045   CallDynamicJavaNode &call = (CallDynamicJavaNode&)n;
1046   return CallJavaNode::cmp(call);
1047 }
1048 #ifndef PRODUCT
1049 void CallDynamicJavaNode::dump_spec(outputStream *st) const {
1050   st->print("# Dynamic ");
1051   CallJavaNode::dump_spec(st);
1052 }
1053 #endif
1054 
1055 //=============================================================================
1056 uint CallRuntimeNode::size_of() const { return sizeof(*this); }
1057 uint CallRuntimeNode::cmp( const Node &n ) const {
1058   CallRuntimeNode &call = (CallRuntimeNode&)n;
1059   return CallNode::cmp(call) && !strcmp(_name,call._name);
1060 }
1061 #ifndef PRODUCT
1062 void CallRuntimeNode::dump_spec(outputStream *st) const {
1063   st->print("# ");
1064   st->print("%s", _name);
1065   CallNode::dump_spec(st);
1066 }
1067 #endif
1068 
1069 //------------------------------calling_convention-----------------------------
1070 void CallRuntimeNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
1071   Matcher::c_calling_convention( sig_bt, parm_regs, argcnt );
1072 }
1073 
1074 //=============================================================================
1075 //------------------------------calling_convention-----------------------------
1076 
1077 
1078 //=============================================================================
1079 uint CallLeafNode::size_of() const { return sizeof(*this); }
1080 uint CallLeafNode::cmp(const Node &n) const {
1081   CallLeafNode &call = (CallLeafNode&)n;
1082   return CallRuntimeNode::cmp(call) && _preserves_fp_registers == call._preserves_fp_registers;
1083 }
1084 
1085 #ifndef PRODUCT
1086 void CallLeafNode::dump_spec(outputStream *st) const {
1087   st->print("# ");
1088   st->print("%s", _name);
1089   if (_preserves_fp_registers) {
1090     st->print("preserves_fp_registers");
1091   }
1092   CallNode::dump_spec(st);
1093 }
1094 #endif
1095 
1096 //=============================================================================
1097 
1098 void SafePointNode::set_local(JVMState* jvms, uint idx, Node *c) {
1099   assert(verify_jvms(jvms), "jvms must match");
1100   int loc = jvms->locoff() + idx;
1101   if (in(loc)->is_top() && idx > 0 && !c->is_top() ) {
1102     // If current local idx is top then local idx - 1 could
1103     // be a long/double that needs to be killed since top could
1104     // represent the 2nd half ofthe long/double.
1105     uint ideal = in(loc -1)->ideal_reg();
1106     if (ideal == Op_RegD || ideal == Op_RegL) {
1107       // set other (low index) half to top
1108       set_req(loc - 1, in(loc));
1109     }
1110   }
1111   set_req(loc, c);
1112 }
1113 
1114 uint SafePointNode::size_of() const { return sizeof(*this); }
1115 uint SafePointNode::cmp( const Node &n ) const {
1116   return (&n == this);          // Always fail except on self
1117 }
1118 
1119 //-------------------------set_next_exception----------------------------------
1120 void SafePointNode::set_next_exception(SafePointNode* n) {
1121   assert(n == NULL || n->Opcode() == Op_SafePoint, "correct value for next_exception");
1122   if (len() == req()) {
1123     if (n != NULL)  add_prec(n);
1124   } else {
1125     set_prec(req(), n);
1126   }
1127 }
1128 
1129 
1130 //----------------------------next_exception-----------------------------------
1131 SafePointNode* SafePointNode::next_exception() const {
1132   if (len() == req()) {
1133     return NULL;
1134   } else {
1135     Node* n = in(req());
1136     assert(n == NULL || n->Opcode() == Op_SafePoint, "no other uses of prec edges");
1137     return (SafePointNode*) n;
1138   }
1139 }
1140 
1141 
1142 //------------------------------Ideal------------------------------------------
1143 // Skip over any collapsed Regions
1144 Node *SafePointNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1145   return remove_dead_region(phase, can_reshape) ? this : NULL;
1146 }
1147 
1148 //------------------------------Identity---------------------------------------
1149 // Remove obviously duplicate safepoints
1150 Node* SafePointNode::Identity(PhaseGVN* phase) {
1151 
1152   // If you have back to back safepoints, remove one
1153   if( in(TypeFunc::Control)->is_SafePoint() )
1154     return in(TypeFunc::Control);
1155 
1156   if( in(0)->is_Proj() ) {
1157     Node *n0 = in(0)->in(0);
1158     // Check if he is a call projection (except Leaf Call)
1159     if( n0->is_Catch() ) {
1160       n0 = n0->in(0)->in(0);
1161       assert( n0->is_Call(), "expect a call here" );
1162     }
1163     if( n0->is_Call() && n0->as_Call()->guaranteed_safepoint() ) {
1164       // Don't remove a safepoint belonging to an OuterStripMinedLoopEndNode.
1165       // If the loop dies, they will be removed together.
1166       if (has_out_with(Op_OuterStripMinedLoopEnd)) {
1167         return this;
1168       }
1169       // Useless Safepoint, so remove it
1170       return in(TypeFunc::Control);
1171     }
1172   }
1173 
1174   return this;
1175 }
1176 
1177 //------------------------------Value------------------------------------------
1178 const Type* SafePointNode::Value(PhaseGVN* phase) const {
1179   if( phase->type(in(0)) == Type::TOP ) return Type::TOP;
1180   if( phase->eqv( in(0), this ) ) return Type::TOP; // Dead infinite loop
1181   return Type::CONTROL;
1182 }
1183 
1184 #ifndef PRODUCT
1185 void SafePointNode::dump_spec(outputStream *st) const {
1186   st->print(" SafePoint ");
1187   _replaced_nodes.dump(st);
1188 }
1189 
1190 // The related nodes of a SafepointNode are all data inputs, excluding the
1191 // control boundary, as well as all outputs till level 2 (to include projection
1192 // nodes and targets). In compact mode, just include inputs till level 1 and
1193 // outputs as before.
1194 void SafePointNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1195   if (compact) {
1196     this->collect_nodes(in_rel, 1, false, false);
1197   } else {
1198     this->collect_nodes_in_all_data(in_rel, false);
1199   }
1200   this->collect_nodes(out_rel, -2, false, false);
1201 }
1202 #endif
1203 
1204 const RegMask &SafePointNode::in_RegMask(uint idx) const {
1205   if( idx < TypeFunc::Parms ) return RegMask::Empty;
1206   // Values outside the domain represent debug info
1207   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
1208 }
1209 const RegMask &SafePointNode::out_RegMask() const {
1210   return RegMask::Empty;
1211 }
1212 
1213 
1214 void SafePointNode::grow_stack(JVMState* jvms, uint grow_by) {
1215   assert((int)grow_by > 0, "sanity");
1216   int monoff = jvms->monoff();
1217   int scloff = jvms->scloff();
1218   int endoff = jvms->endoff();
1219   assert(endoff == (int)req(), "no other states or debug info after me");
1220   Node* top = Compile::current()->top();
1221   for (uint i = 0; i < grow_by; i++) {
1222     ins_req(monoff, top);
1223   }
1224   jvms->set_monoff(monoff + grow_by);
1225   jvms->set_scloff(scloff + grow_by);
1226   jvms->set_endoff(endoff + grow_by);
1227 }
1228 
1229 void SafePointNode::push_monitor(const FastLockNode *lock) {
1230   // Add a LockNode, which points to both the original BoxLockNode (the
1231   // stack space for the monitor) and the Object being locked.
1232   const int MonitorEdges = 2;
1233   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
1234   assert(req() == jvms()->endoff(), "correct sizing");
1235   int nextmon = jvms()->scloff();
1236   if (GenerateSynchronizationCode) {
1237     ins_req(nextmon,   lock->box_node());
1238     ins_req(nextmon+1, lock->obj_node());
1239   } else {
1240     Node* top = Compile::current()->top();
1241     ins_req(nextmon, top);
1242     ins_req(nextmon, top);
1243   }
1244   jvms()->set_scloff(nextmon + MonitorEdges);
1245   jvms()->set_endoff(req());
1246 }
1247 
1248 void SafePointNode::pop_monitor() {
1249   // Delete last monitor from debug info
1250   debug_only(int num_before_pop = jvms()->nof_monitors());
1251   const int MonitorEdges = 2;
1252   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
1253   int scloff = jvms()->scloff();
1254   int endoff = jvms()->endoff();
1255   int new_scloff = scloff - MonitorEdges;
1256   int new_endoff = endoff - MonitorEdges;
1257   jvms()->set_scloff(new_scloff);
1258   jvms()->set_endoff(new_endoff);
1259   while (scloff > new_scloff)  del_req_ordered(--scloff);
1260   assert(jvms()->nof_monitors() == num_before_pop-1, "");
1261 }
1262 
1263 Node *SafePointNode::peek_monitor_box() const {
1264   int mon = jvms()->nof_monitors() - 1;
1265   assert(mon >= 0, "must have a monitor");
1266   return monitor_box(jvms(), mon);
1267 }
1268 
1269 Node *SafePointNode::peek_monitor_obj() const {
1270   int mon = jvms()->nof_monitors() - 1;
1271   assert(mon >= 0, "must have a monitor");
1272   return monitor_obj(jvms(), mon);
1273 }
1274 
1275 // Do we Match on this edge index or not?  Match no edges
1276 uint SafePointNode::match_edge(uint idx) const {
1277   if( !needs_polling_address_input() )
1278     return 0;
1279 
1280   return (TypeFunc::Parms == idx);
1281 }
1282 
1283 //==============  SafePointScalarObjectNode  ==============
1284 
1285 SafePointScalarObjectNode::SafePointScalarObjectNode(const TypeOopPtr* tp,
1286 #ifdef ASSERT
1287                                                      AllocateNode* alloc,
1288 #endif
1289                                                      uint first_index,
1290                                                      uint n_fields) :
1291   TypeNode(tp, 1), // 1 control input -- seems required.  Get from root.
1292   _first_index(first_index),
1293   _n_fields(n_fields)
1294 #ifdef ASSERT
1295   , _alloc(alloc)
1296 #endif
1297 {
1298   init_class_id(Class_SafePointScalarObject);
1299 }
1300 
1301 // Do not allow value-numbering for SafePointScalarObject node.
1302 uint SafePointScalarObjectNode::hash() const { return NO_HASH; }
1303 uint SafePointScalarObjectNode::cmp( const Node &n ) const {
1304   return (&n == this); // Always fail except on self
1305 }
1306 
1307 uint SafePointScalarObjectNode::ideal_reg() const {
1308   return 0; // No matching to machine instruction
1309 }
1310 
1311 const RegMask &SafePointScalarObjectNode::in_RegMask(uint idx) const {
1312   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
1313 }
1314 
1315 const RegMask &SafePointScalarObjectNode::out_RegMask() const {
1316   return RegMask::Empty;
1317 }
1318 
1319 uint SafePointScalarObjectNode::match_edge(uint idx) const {
1320   return 0;
1321 }
1322 
1323 SafePointScalarObjectNode*
1324 SafePointScalarObjectNode::clone(Dict* sosn_map) const {
1325   void* cached = (*sosn_map)[(void*)this];
1326   if (cached != NULL) {
1327     return (SafePointScalarObjectNode*)cached;
1328   }
1329   SafePointScalarObjectNode* res = (SafePointScalarObjectNode*)Node::clone();
1330   sosn_map->Insert((void*)this, (void*)res);
1331   return res;
1332 }
1333 
1334 
1335 #ifndef PRODUCT
1336 void SafePointScalarObjectNode::dump_spec(outputStream *st) const {
1337   st->print(" # fields@[%d..%d]", first_index(),
1338              first_index() + n_fields() - 1);
1339 }
1340 
1341 #endif
1342 
1343 //=============================================================================
1344 uint AllocateNode::size_of() const { return sizeof(*this); }
1345 
1346 AllocateNode::AllocateNode(Compile* C, const TypeFunc *atype,
1347                            Node *ctrl, Node *mem, Node *abio,
1348                            Node *size, Node *klass_node, Node *initial_test)
1349   : CallNode(atype, NULL, TypeRawPtr::BOTTOM)
1350 {
1351   init_class_id(Class_Allocate);
1352   init_flags(Flag_is_macro);
1353   _is_scalar_replaceable = false;
1354   _is_non_escaping = false;
1355   _is_allocation_MemBar_redundant = false;
1356   Node *topnode = C->top();
1357 
1358   init_req( TypeFunc::Control  , ctrl );
1359   init_req( TypeFunc::I_O      , abio );
1360   init_req( TypeFunc::Memory   , mem );
1361   init_req( TypeFunc::ReturnAdr, topnode );
1362   init_req( TypeFunc::FramePtr , topnode );
1363   init_req( AllocSize          , size);
1364   init_req( KlassNode          , klass_node);
1365   init_req( InitialTest        , initial_test);
1366   init_req( ALength            , topnode);
1367   C->add_macro_node(this);
1368 }
1369 
1370 void AllocateNode::compute_MemBar_redundancy(ciMethod* initializer)
1371 {
1372   assert(initializer != NULL &&
1373          initializer->is_initializer() &&
1374          !initializer->is_static(),
1375              "unexpected initializer method");
1376   BCEscapeAnalyzer* analyzer = initializer->get_bcea();
1377   if (analyzer == NULL) {
1378     return;
1379   }
1380 
1381   // Allocation node is first parameter in its initializer
1382   if (analyzer->is_arg_stack(0) || analyzer->is_arg_local(0)) {
1383     _is_allocation_MemBar_redundant = true;
1384   }
1385 }
1386 
1387 //=============================================================================
1388 Node* AllocateArrayNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1389   if (remove_dead_region(phase, can_reshape))  return this;
1390   // Don't bother trying to transform a dead node
1391   if (in(0) && in(0)->is_top())  return NULL;
1392 
1393   const Type* type = phase->type(Ideal_length());
1394   if (type->isa_int() && type->is_int()->_hi < 0) {
1395     if (can_reshape) {
1396       PhaseIterGVN *igvn = phase->is_IterGVN();
1397       // Unreachable fall through path (negative array length),
1398       // the allocation can only throw so disconnect it.
1399       Node* proj = proj_out_or_null(TypeFunc::Control);
1400       Node* catchproj = NULL;
1401       if (proj != NULL) {
1402         for (DUIterator_Fast imax, i = proj->fast_outs(imax); i < imax; i++) {
1403           Node *cn = proj->fast_out(i);
1404           if (cn->is_Catch()) {
1405             catchproj = cn->as_Multi()->proj_out_or_null(CatchProjNode::fall_through_index);
1406             break;
1407           }
1408         }
1409       }
1410       if (catchproj != NULL && catchproj->outcnt() > 0 &&
1411           (catchproj->outcnt() > 1 ||
1412            catchproj->unique_out()->Opcode() != Op_Halt)) {
1413         assert(catchproj->is_CatchProj(), "must be a CatchProjNode");
1414         Node* nproj = catchproj->clone();
1415         igvn->register_new_node_with_optimizer(nproj);
1416 
1417         Node *frame = new ParmNode( phase->C->start(), TypeFunc::FramePtr );
1418         frame = phase->transform(frame);
1419         // Halt & Catch Fire
1420         Node *halt = new HaltNode( nproj, frame );
1421         phase->C->root()->add_req(halt);
1422         phase->transform(halt);
1423 
1424         igvn->replace_node(catchproj, phase->C->top());
1425         return this;
1426       }
1427     } else {
1428       // Can't correct it during regular GVN so register for IGVN
1429       phase->C->record_for_igvn(this);
1430     }
1431   }
1432   return NULL;
1433 }
1434 
1435 // Retrieve the length from the AllocateArrayNode. Narrow the type with a
1436 // CastII, if appropriate.  If we are not allowed to create new nodes, and
1437 // a CastII is appropriate, return NULL.
1438 Node *AllocateArrayNode::make_ideal_length(const TypeOopPtr* oop_type, PhaseTransform *phase, bool allow_new_nodes) {
1439   Node *length = in(AllocateNode::ALength);
1440   assert(length != NULL, "length is not null");
1441 
1442   const TypeInt* length_type = phase->find_int_type(length);
1443   const TypeAryPtr* ary_type = oop_type->isa_aryptr();
1444 
1445   if (ary_type != NULL && length_type != NULL) {
1446     const TypeInt* narrow_length_type = ary_type->narrow_size_type(length_type);
1447     if (narrow_length_type != length_type) {
1448       // Assert one of:
1449       //   - the narrow_length is 0
1450       //   - the narrow_length is not wider than length
1451       assert(narrow_length_type == TypeInt::ZERO ||
1452              length_type->is_con() && narrow_length_type->is_con() &&
1453                 (narrow_length_type->_hi <= length_type->_lo) ||
1454              (narrow_length_type->_hi <= length_type->_hi &&
1455               narrow_length_type->_lo >= length_type->_lo),
1456              "narrow type must be narrower than length type");
1457 
1458       // Return NULL if new nodes are not allowed
1459       if (!allow_new_nodes) return NULL;
1460       // Create a cast which is control dependent on the initialization to
1461       // propagate the fact that the array length must be positive.
1462       InitializeNode* init = initialization();
1463       assert(init != NULL, "initialization not found");
1464       length = new CastIINode(length, narrow_length_type);
1465       length->set_req(0, init->proj_out_or_null(0));
1466     }
1467   }
1468 
1469   return length;
1470 }
1471 
1472 //=============================================================================
1473 uint LockNode::size_of() const { return sizeof(*this); }
1474 
1475 // Redundant lock elimination
1476 //
1477 // There are various patterns of locking where we release and
1478 // immediately reacquire a lock in a piece of code where no operations
1479 // occur in between that would be observable.  In those cases we can
1480 // skip releasing and reacquiring the lock without violating any
1481 // fairness requirements.  Doing this around a loop could cause a lock
1482 // to be held for a very long time so we concentrate on non-looping
1483 // control flow.  We also require that the operations are fully
1484 // redundant meaning that we don't introduce new lock operations on
1485 // some paths so to be able to eliminate it on others ala PRE.  This
1486 // would probably require some more extensive graph manipulation to
1487 // guarantee that the memory edges were all handled correctly.
1488 //
1489 // Assuming p is a simple predicate which can't trap in any way and s
1490 // is a synchronized method consider this code:
1491 //
1492 //   s();
1493 //   if (p)
1494 //     s();
1495 //   else
1496 //     s();
1497 //   s();
1498 //
1499 // 1. The unlocks of the first call to s can be eliminated if the
1500 // locks inside the then and else branches are eliminated.
1501 //
1502 // 2. The unlocks of the then and else branches can be eliminated if
1503 // the lock of the final call to s is eliminated.
1504 //
1505 // Either of these cases subsumes the simple case of sequential control flow
1506 //
1507 // Addtionally we can eliminate versions without the else case:
1508 //
1509 //   s();
1510 //   if (p)
1511 //     s();
1512 //   s();
1513 //
1514 // 3. In this case we eliminate the unlock of the first s, the lock
1515 // and unlock in the then case and the lock in the final s.
1516 //
1517 // Note also that in all these cases the then/else pieces don't have
1518 // to be trivial as long as they begin and end with synchronization
1519 // operations.
1520 //
1521 //   s();
1522 //   if (p)
1523 //     s();
1524 //     f();
1525 //     s();
1526 //   s();
1527 //
1528 // The code will work properly for this case, leaving in the unlock
1529 // before the call to f and the relock after it.
1530 //
1531 // A potentially interesting case which isn't handled here is when the
1532 // locking is partially redundant.
1533 //
1534 //   s();
1535 //   if (p)
1536 //     s();
1537 //
1538 // This could be eliminated putting unlocking on the else case and
1539 // eliminating the first unlock and the lock in the then side.
1540 // Alternatively the unlock could be moved out of the then side so it
1541 // was after the merge and the first unlock and second lock
1542 // eliminated.  This might require less manipulation of the memory
1543 // state to get correct.
1544 //
1545 // Additionally we might allow work between a unlock and lock before
1546 // giving up eliminating the locks.  The current code disallows any
1547 // conditional control flow between these operations.  A formulation
1548 // similar to partial redundancy elimination computing the
1549 // availability of unlocking and the anticipatability of locking at a
1550 // program point would allow detection of fully redundant locking with
1551 // some amount of work in between.  I'm not sure how often I really
1552 // think that would occur though.  Most of the cases I've seen
1553 // indicate it's likely non-trivial work would occur in between.
1554 // There may be other more complicated constructs where we could
1555 // eliminate locking but I haven't seen any others appear as hot or
1556 // interesting.
1557 //
1558 // Locking and unlocking have a canonical form in ideal that looks
1559 // roughly like this:
1560 //
1561 //              <obj>
1562 //                | \\------+
1563 //                |  \       \
1564 //                | BoxLock   \
1565 //                |  |   |     \
1566 //                |  |    \     \
1567 //                |  |   FastLock
1568 //                |  |   /
1569 //                |  |  /
1570 //                |  |  |
1571 //
1572 //               Lock
1573 //                |
1574 //            Proj #0
1575 //                |
1576 //            MembarAcquire
1577 //                |
1578 //            Proj #0
1579 //
1580 //            MembarRelease
1581 //                |
1582 //            Proj #0
1583 //                |
1584 //              Unlock
1585 //                |
1586 //            Proj #0
1587 //
1588 //
1589 // This code proceeds by processing Lock nodes during PhaseIterGVN
1590 // and searching back through its control for the proper code
1591 // patterns.  Once it finds a set of lock and unlock operations to
1592 // eliminate they are marked as eliminatable which causes the
1593 // expansion of the Lock and Unlock macro nodes to make the operation a NOP
1594 //
1595 //=============================================================================
1596 
1597 //
1598 // Utility function to skip over uninteresting control nodes.  Nodes skipped are:
1599 //   - copy regions.  (These may not have been optimized away yet.)
1600 //   - eliminated locking nodes
1601 //
1602 static Node *next_control(Node *ctrl) {
1603   if (ctrl == NULL)
1604     return NULL;
1605   while (1) {
1606     if (ctrl->is_Region()) {
1607       RegionNode *r = ctrl->as_Region();
1608       Node *n = r->is_copy();
1609       if (n == NULL)
1610         break;  // hit a region, return it
1611       else
1612         ctrl = n;
1613     } else if (ctrl->is_Proj()) {
1614       Node *in0 = ctrl->in(0);
1615       if (in0->is_AbstractLock() && in0->as_AbstractLock()->is_eliminated()) {
1616         ctrl = in0->in(0);
1617       } else {
1618         break;
1619       }
1620     } else {
1621       break; // found an interesting control
1622     }
1623   }
1624   return ctrl;
1625 }
1626 //
1627 // Given a control, see if it's the control projection of an Unlock which
1628 // operating on the same object as lock.
1629 //
1630 bool AbstractLockNode::find_matching_unlock(const Node* ctrl, LockNode* lock,
1631                                             GrowableArray<AbstractLockNode*> &lock_ops) {
1632   ProjNode *ctrl_proj = (ctrl->is_Proj()) ? ctrl->as_Proj() : NULL;
1633   if (ctrl_proj != NULL && ctrl_proj->_con == TypeFunc::Control) {
1634     Node *n = ctrl_proj->in(0);
1635     if (n != NULL && n->is_Unlock()) {
1636       UnlockNode *unlock = n->as_Unlock();
1637       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1638       Node* lock_obj = bs->step_over_gc_barrier(lock->obj_node());
1639       Node* unlock_obj = bs->step_over_gc_barrier(unlock->obj_node());
1640       if (lock_obj->eqv_uncast(unlock_obj) &&
1641           BoxLockNode::same_slot(lock->box_node(), unlock->box_node()) &&
1642           !unlock->is_eliminated()) {
1643         lock_ops.append(unlock);
1644         return true;
1645       }
1646     }
1647   }
1648   return false;
1649 }
1650 
1651 //
1652 // Find the lock matching an unlock.  Returns null if a safepoint
1653 // or complicated control is encountered first.
1654 LockNode *AbstractLockNode::find_matching_lock(UnlockNode* unlock) {
1655   LockNode *lock_result = NULL;
1656   // find the matching lock, or an intervening safepoint
1657   Node *ctrl = next_control(unlock->in(0));
1658   while (1) {
1659     assert(ctrl != NULL, "invalid control graph");
1660     assert(!ctrl->is_Start(), "missing lock for unlock");
1661     if (ctrl->is_top()) break;  // dead control path
1662     if (ctrl->is_Proj()) ctrl = ctrl->in(0);
1663     if (ctrl->is_SafePoint()) {
1664         break;  // found a safepoint (may be the lock we are searching for)
1665     } else if (ctrl->is_Region()) {
1666       // Check for a simple diamond pattern.  Punt on anything more complicated
1667       if (ctrl->req() == 3 && ctrl->in(1) != NULL && ctrl->in(2) != NULL) {
1668         Node *in1 = next_control(ctrl->in(1));
1669         Node *in2 = next_control(ctrl->in(2));
1670         if (((in1->is_IfTrue() && in2->is_IfFalse()) ||
1671              (in2->is_IfTrue() && in1->is_IfFalse())) && (in1->in(0) == in2->in(0))) {
1672           ctrl = next_control(in1->in(0)->in(0));
1673         } else {
1674           break;
1675         }
1676       } else {
1677         break;
1678       }
1679     } else {
1680       ctrl = next_control(ctrl->in(0));  // keep searching
1681     }
1682   }
1683   if (ctrl->is_Lock()) {
1684     LockNode *lock = ctrl->as_Lock();
1685     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1686     Node* lock_obj = bs->step_over_gc_barrier(lock->obj_node());
1687     Node* unlock_obj = bs->step_over_gc_barrier(unlock->obj_node());
1688     if (lock_obj->eqv_uncast(unlock_obj) &&
1689         BoxLockNode::same_slot(lock->box_node(), unlock->box_node())) {
1690       lock_result = lock;
1691     }
1692   }
1693   return lock_result;
1694 }
1695 
1696 // This code corresponds to case 3 above.
1697 
1698 bool AbstractLockNode::find_lock_and_unlock_through_if(Node* node, LockNode* lock,
1699                                                        GrowableArray<AbstractLockNode*> &lock_ops) {
1700   Node* if_node = node->in(0);
1701   bool  if_true = node->is_IfTrue();
1702 
1703   if (if_node->is_If() && if_node->outcnt() == 2 && (if_true || node->is_IfFalse())) {
1704     Node *lock_ctrl = next_control(if_node->in(0));
1705     if (find_matching_unlock(lock_ctrl, lock, lock_ops)) {
1706       Node* lock1_node = NULL;
1707       ProjNode* proj = if_node->as_If()->proj_out(!if_true);
1708       if (if_true) {
1709         if (proj->is_IfFalse() && proj->outcnt() == 1) {
1710           lock1_node = proj->unique_out();
1711         }
1712       } else {
1713         if (proj->is_IfTrue() && proj->outcnt() == 1) {
1714           lock1_node = proj->unique_out();
1715         }
1716       }
1717       if (lock1_node != NULL && lock1_node->is_Lock()) {
1718         LockNode *lock1 = lock1_node->as_Lock();
1719         BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1720         Node* lock_obj = bs->step_over_gc_barrier(lock->obj_node());
1721         Node* lock1_obj = bs->step_over_gc_barrier(lock1->obj_node());
1722         if (lock_obj->eqv_uncast(lock1_obj) &&
1723             BoxLockNode::same_slot(lock->box_node(), lock1->box_node()) &&
1724             !lock1->is_eliminated()) {
1725           lock_ops.append(lock1);
1726           return true;
1727         }
1728       }
1729     }
1730   }
1731 
1732   lock_ops.trunc_to(0);
1733   return false;
1734 }
1735 
1736 bool AbstractLockNode::find_unlocks_for_region(const RegionNode* region, LockNode* lock,
1737                                GrowableArray<AbstractLockNode*> &lock_ops) {
1738   // check each control merging at this point for a matching unlock.
1739   // in(0) should be self edge so skip it.
1740   for (int i = 1; i < (int)region->req(); i++) {
1741     Node *in_node = next_control(region->in(i));
1742     if (in_node != NULL) {
1743       if (find_matching_unlock(in_node, lock, lock_ops)) {
1744         // found a match so keep on checking.
1745         continue;
1746       } else if (find_lock_and_unlock_through_if(in_node, lock, lock_ops)) {
1747         continue;
1748       }
1749 
1750       // If we fall through to here then it was some kind of node we
1751       // don't understand or there wasn't a matching unlock, so give
1752       // up trying to merge locks.
1753       lock_ops.trunc_to(0);
1754       return false;
1755     }
1756   }
1757   return true;
1758 
1759 }
1760 
1761 #ifndef PRODUCT
1762 //
1763 // Create a counter which counts the number of times this lock is acquired
1764 //
1765 void AbstractLockNode::create_lock_counter(JVMState* state) {
1766   _counter = OptoRuntime::new_named_counter(state, NamedCounter::LockCounter);
1767 }
1768 
1769 void AbstractLockNode::set_eliminated_lock_counter() {
1770   if (_counter) {
1771     // Update the counter to indicate that this lock was eliminated.
1772     // The counter update code will stay around even though the
1773     // optimizer will eliminate the lock operation itself.
1774     _counter->set_tag(NamedCounter::EliminatedLockCounter);
1775   }
1776 }
1777 
1778 const char* AbstractLockNode::_kind_names[] = {"Regular", "NonEscObj", "Coarsened", "Nested"};
1779 
1780 void AbstractLockNode::dump_spec(outputStream* st) const {
1781   st->print("%s ", _kind_names[_kind]);
1782   CallNode::dump_spec(st);
1783 }
1784 
1785 void AbstractLockNode::dump_compact_spec(outputStream* st) const {
1786   st->print("%s", _kind_names[_kind]);
1787 }
1788 
1789 // The related set of lock nodes includes the control boundary.
1790 void AbstractLockNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1791   if (compact) {
1792       this->collect_nodes(in_rel, 1, false, false);
1793     } else {
1794       this->collect_nodes_in_all_data(in_rel, true);
1795     }
1796     this->collect_nodes(out_rel, -2, false, false);
1797 }
1798 #endif
1799 
1800 //=============================================================================
1801 Node *LockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1802 
1803   // perform any generic optimizations first (returns 'this' or NULL)
1804   Node *result = SafePointNode::Ideal(phase, can_reshape);
1805   if (result != NULL)  return result;
1806   // Don't bother trying to transform a dead node
1807   if (in(0) && in(0)->is_top())  return NULL;
1808 
1809   // Now see if we can optimize away this lock.  We don't actually
1810   // remove the locking here, we simply set the _eliminate flag which
1811   // prevents macro expansion from expanding the lock.  Since we don't
1812   // modify the graph, the value returned from this function is the
1813   // one computed above.
1814   if (can_reshape && EliminateLocks && !is_non_esc_obj()) {
1815     //
1816     // If we are locking an unescaped object, the lock/unlock is unnecessary
1817     //
1818     ConnectionGraph *cgr = phase->C->congraph();
1819     if (cgr != NULL && cgr->not_global_escape(obj_node())) {
1820       assert(!is_eliminated() || is_coarsened(), "sanity");
1821       // The lock could be marked eliminated by lock coarsening
1822       // code during first IGVN before EA. Replace coarsened flag
1823       // to eliminate all associated locks/unlocks.
1824 #ifdef ASSERT
1825       this->log_lock_optimization(phase->C,"eliminate_lock_set_non_esc1");
1826 #endif
1827       this->set_non_esc_obj();
1828       return result;
1829     }
1830 
1831     //
1832     // Try lock coarsening
1833     //
1834     PhaseIterGVN* iter = phase->is_IterGVN();
1835     if (iter != NULL && !is_eliminated()) {
1836 
1837       GrowableArray<AbstractLockNode*>   lock_ops;
1838 
1839       Node *ctrl = next_control(in(0));
1840 
1841       // now search back for a matching Unlock
1842       if (find_matching_unlock(ctrl, this, lock_ops)) {
1843         // found an unlock directly preceding this lock.  This is the
1844         // case of single unlock directly control dependent on a
1845         // single lock which is the trivial version of case 1 or 2.
1846       } else if (ctrl->is_Region() ) {
1847         if (find_unlocks_for_region(ctrl->as_Region(), this, lock_ops)) {
1848         // found lock preceded by multiple unlocks along all paths
1849         // joining at this point which is case 3 in description above.
1850         }
1851       } else {
1852         // see if this lock comes from either half of an if and the
1853         // predecessors merges unlocks and the other half of the if
1854         // performs a lock.
1855         if (find_lock_and_unlock_through_if(ctrl, this, lock_ops)) {
1856           // found unlock splitting to an if with locks on both branches.
1857         }
1858       }
1859 
1860       if (lock_ops.length() > 0) {
1861         // add ourselves to the list of locks to be eliminated.
1862         lock_ops.append(this);
1863 
1864   #ifndef PRODUCT
1865         if (PrintEliminateLocks) {
1866           int locks = 0;
1867           int unlocks = 0;
1868           for (int i = 0; i < lock_ops.length(); i++) {
1869             AbstractLockNode* lock = lock_ops.at(i);
1870             if (lock->Opcode() == Op_Lock)
1871               locks++;
1872             else
1873               unlocks++;
1874             if (Verbose) {
1875               lock->dump(1);
1876             }
1877           }
1878           tty->print_cr("***Eliminated %d unlocks and %d locks", unlocks, locks);
1879         }
1880   #endif
1881 
1882         // for each of the identified locks, mark them
1883         // as eliminatable
1884         for (int i = 0; i < lock_ops.length(); i++) {
1885           AbstractLockNode* lock = lock_ops.at(i);
1886 
1887           // Mark it eliminated by coarsening and update any counters
1888 #ifdef ASSERT
1889           lock->log_lock_optimization(phase->C, "eliminate_lock_set_coarsened");
1890 #endif
1891           lock->set_coarsened();
1892         }
1893       } else if (ctrl->is_Region() &&
1894                  iter->_worklist.member(ctrl)) {
1895         // We weren't able to find any opportunities but the region this
1896         // lock is control dependent on hasn't been processed yet so put
1897         // this lock back on the worklist so we can check again once any
1898         // region simplification has occurred.
1899         iter->_worklist.push(this);
1900       }
1901     }
1902   }
1903 
1904   return result;
1905 }
1906 
1907 //=============================================================================
1908 bool LockNode::is_nested_lock_region() {
1909   return is_nested_lock_region(NULL);
1910 }
1911 
1912 // p is used for access to compilation log; no logging if NULL
1913 bool LockNode::is_nested_lock_region(Compile * c) {
1914   BoxLockNode* box = box_node()->as_BoxLock();
1915   int stk_slot = box->stack_slot();
1916   if (stk_slot <= 0) {
1917 #ifdef ASSERT
1918     this->log_lock_optimization(c, "eliminate_lock_INLR_1");
1919 #endif
1920     return false; // External lock or it is not Box (Phi node).
1921   }
1922 
1923   // Ignore complex cases: merged locks or multiple locks.
1924   Node* obj = obj_node();
1925   LockNode* unique_lock = NULL;
1926   if (!box->is_simple_lock_region(&unique_lock, obj)) {
1927 #ifdef ASSERT
1928     this->log_lock_optimization(c, "eliminate_lock_INLR_2a");
1929 #endif
1930     return false;
1931   }
1932   if (unique_lock != this) {
1933 #ifdef ASSERT
1934     this->log_lock_optimization(c, "eliminate_lock_INLR_2b");
1935 #endif
1936     return false;
1937   }
1938 
1939   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1940   obj = bs->step_over_gc_barrier(obj);
1941   // Look for external lock for the same object.
1942   SafePointNode* sfn = this->as_SafePoint();
1943   JVMState* youngest_jvms = sfn->jvms();
1944   int max_depth = youngest_jvms->depth();
1945   for (int depth = 1; depth <= max_depth; depth++) {
1946     JVMState* jvms = youngest_jvms->of_depth(depth);
1947     int num_mon  = jvms->nof_monitors();
1948     // Loop over monitors
1949     for (int idx = 0; idx < num_mon; idx++) {
1950       Node* obj_node = sfn->monitor_obj(jvms, idx);
1951       obj_node = bs->step_over_gc_barrier(obj_node);
1952       BoxLockNode* box_node = sfn->monitor_box(jvms, idx)->as_BoxLock();
1953       if ((box_node->stack_slot() < stk_slot) && obj_node->eqv_uncast(obj)) {
1954         return true;
1955       }
1956     }
1957   }
1958 #ifdef ASSERT
1959   this->log_lock_optimization(c, "eliminate_lock_INLR_3");
1960 #endif
1961   return false;
1962 }
1963 
1964 //=============================================================================
1965 uint UnlockNode::size_of() const { return sizeof(*this); }
1966 
1967 //=============================================================================
1968 Node *UnlockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1969 
1970   // perform any generic optimizations first (returns 'this' or NULL)
1971   Node *result = SafePointNode::Ideal(phase, can_reshape);
1972   if (result != NULL)  return result;
1973   // Don't bother trying to transform a dead node
1974   if (in(0) && in(0)->is_top())  return NULL;
1975 
1976   // Now see if we can optimize away this unlock.  We don't actually
1977   // remove the unlocking here, we simply set the _eliminate flag which
1978   // prevents macro expansion from expanding the unlock.  Since we don't
1979   // modify the graph, the value returned from this function is the
1980   // one computed above.
1981   // Escape state is defined after Parse phase.
1982   if (can_reshape && EliminateLocks && !is_non_esc_obj()) {
1983     //
1984     // If we are unlocking an unescaped object, the lock/unlock is unnecessary.
1985     //
1986     ConnectionGraph *cgr = phase->C->congraph();
1987     if (cgr != NULL && cgr->not_global_escape(obj_node())) {
1988       assert(!is_eliminated() || is_coarsened(), "sanity");
1989       // The lock could be marked eliminated by lock coarsening
1990       // code during first IGVN before EA. Replace coarsened flag
1991       // to eliminate all associated locks/unlocks.
1992 #ifdef ASSERT
1993       this->log_lock_optimization(phase->C, "eliminate_lock_set_non_esc2");
1994 #endif
1995       this->set_non_esc_obj();
1996     }
1997   }
1998   return result;
1999 }
2000 
2001 const char * AbstractLockNode::kind_as_string() const {
2002   return is_coarsened()   ? "coarsened" :
2003          is_nested()      ? "nested" :
2004          is_non_esc_obj() ? "non_escaping" :
2005          "?";
2006 }
2007 
2008 void AbstractLockNode::log_lock_optimization(Compile *C, const char * tag)  const {
2009   if (C == NULL) {
2010     return;
2011   }
2012   CompileLog* log = C->log();
2013   if (log != NULL) {
2014     log->begin_head("%s lock='%d' compile_id='%d' class_id='%s' kind='%s'",
2015           tag, is_Lock(), C->compile_id(),
2016           is_Unlock() ? "unlock" : is_Lock() ? "lock" : "?",
2017           kind_as_string());
2018     log->stamp();
2019     log->end_head();
2020     JVMState* p = is_Unlock() ? (as_Unlock()->dbg_jvms()) : jvms();
2021     while (p != NULL) {
2022       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
2023       p = p->caller();
2024     }
2025     log->tail(tag);
2026   }
2027 }
2028 
2029 bool CallNode::may_modify_arraycopy_helper(const TypeOopPtr* dest_t, const TypeOopPtr *t_oop, PhaseTransform *phase) {
2030   if (dest_t->is_known_instance() && t_oop->is_known_instance()) {
2031     return dest_t->instance_id() == t_oop->instance_id();
2032   }
2033 
2034   if (dest_t->isa_instptr() && !dest_t->klass()->equals(phase->C->env()->Object_klass())) {
2035     // clone
2036     if (t_oop->isa_aryptr()) {
2037       return false;
2038     }
2039     if (!t_oop->isa_instptr()) {
2040       return true;
2041     }
2042     if (dest_t->klass()->is_subtype_of(t_oop->klass()) || t_oop->klass()->is_subtype_of(dest_t->klass())) {
2043       return true;
2044     }
2045     // unrelated
2046     return false;
2047   }
2048 
2049   if (dest_t->isa_aryptr()) {
2050     // arraycopy or array clone
2051     if (t_oop->isa_instptr()) {
2052       return false;
2053     }
2054     if (!t_oop->isa_aryptr()) {
2055       return true;
2056     }
2057 
2058     const Type* elem = dest_t->is_aryptr()->elem();
2059     if (elem == Type::BOTTOM) {
2060       // An array but we don't know what elements are
2061       return true;
2062     }
2063 
2064     dest_t = dest_t->add_offset(Type::OffsetBot)->is_oopptr();
2065     uint dest_alias = phase->C->get_alias_index(dest_t);
2066     uint t_oop_alias = phase->C->get_alias_index(t_oop);
2067 
2068     return dest_alias == t_oop_alias;
2069   }
2070 
2071   return true;
2072 }
2073