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/castnode.hpp"
  32 #include "opto/convertnode.hpp"
  33 #include "opto/escape.hpp"
  34 #include "opto/locknode.hpp"
  35 #include "opto/machnode.hpp"
  36 #include "opto/matcher.hpp"
  37 #include "opto/parse.hpp"
  38 #include "opto/regalloc.hpp"
  39 #include "opto/regmask.hpp"
  40 #include "opto/rootnode.hpp"
  41 #include "opto/runtime.hpp"
  42 #include "opto/valuetypenode.hpp"
  43 
  44 // Portions of code courtesy of Clifford Click
  45 
  46 // Optimization - Graph Style
  47 
  48 //=============================================================================
  49 uint StartNode::size_of() const { return sizeof(*this); }
  50 uint StartNode::cmp( const Node &n ) const
  51 { return _domain == ((StartNode&)n)._domain; }
  52 const Type *StartNode::bottom_type() const { return _domain; }
  53 const Type* StartNode::Value(PhaseGVN* phase) const { return _domain; }
  54 #ifndef PRODUCT
  55 void StartNode::dump_spec(outputStream *st) const { st->print(" #"); _domain->dump_on(st);}
  56 void StartNode::dump_compact_spec(outputStream *st) const { /* empty */ }
  57 #endif
  58 
  59 //------------------------------Ideal------------------------------------------
  60 Node *StartNode::Ideal(PhaseGVN *phase, bool can_reshape){
  61   return remove_dead_region(phase, can_reshape) ? this : NULL;
  62 }
  63 
  64 //------------------------------calling_convention-----------------------------
  65 void StartNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
  66   Matcher::calling_convention( sig_bt, parm_regs, argcnt, false );
  67 }
  68 
  69 //------------------------------Registers--------------------------------------
  70 const RegMask &StartNode::in_RegMask(uint) const {
  71   return RegMask::Empty;
  72 }
  73 
  74 //------------------------------match------------------------------------------
  75 // Construct projections for incoming parameters, and their RegMask info
  76 Node *StartNode::match( const ProjNode *proj, const Matcher *match ) {
  77   switch (proj->_con) {
  78   case TypeFunc::Control:
  79   case TypeFunc::I_O:
  80   case TypeFunc::Memory:
  81     return new MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
  82   case TypeFunc::FramePtr:
  83     return new MachProjNode(this,proj->_con,Matcher::c_frame_ptr_mask, Op_RegP);
  84   case TypeFunc::ReturnAdr:
  85     return new MachProjNode(this,proj->_con,match->_return_addr_mask,Op_RegP);
  86   case TypeFunc::Parms:
  87   default: {
  88       uint parm_num = proj->_con - TypeFunc::Parms;
  89       const Type *t = _domain->field_at(proj->_con);
  90       if (t->base() == Type::Half)  // 2nd half of Longs and Doubles
  91         return new ConNode(Type::TOP);
  92       uint ideal_reg = t->ideal_reg();
  93       RegMask &rm = match->_calling_convention_mask[parm_num];
  94       return new MachProjNode(this,proj->_con,rm,ideal_reg);
  95     }
  96   }
  97   return NULL;
  98 }
  99 
 100 //------------------------------StartOSRNode----------------------------------
 101 // The method start node for an on stack replacement adapter
 102 
 103 //------------------------------osr_domain-----------------------------
 104 const TypeTuple *StartOSRNode::osr_domain() {
 105   const Type **fields = TypeTuple::fields(2);
 106   fields[TypeFunc::Parms+0] = TypeRawPtr::BOTTOM;  // address of osr buffer
 107 
 108   return TypeTuple::make(TypeFunc::Parms+1, fields);
 109 }
 110 
 111 //=============================================================================
 112 const char * const ParmNode::names[TypeFunc::Parms+1] = {
 113   "Control", "I_O", "Memory", "FramePtr", "ReturnAdr", "Parms"
 114 };
 115 
 116 #ifndef PRODUCT
 117 void ParmNode::dump_spec(outputStream *st) const {
 118   if( _con < TypeFunc::Parms ) {
 119     st->print("%s", names[_con]);
 120   } else {
 121     st->print("Parm%d: ",_con-TypeFunc::Parms);
 122     // Verbose and WizardMode dump bottom_type for all nodes
 123     if( !Verbose && !WizardMode )   bottom_type()->dump_on(st);
 124   }
 125 }
 126 
 127 void ParmNode::dump_compact_spec(outputStream *st) const {
 128   if (_con < TypeFunc::Parms) {
 129     st->print("%s", names[_con]);
 130   } else {
 131     st->print("%d:", _con-TypeFunc::Parms);
 132     // unconditionally dump bottom_type
 133     bottom_type()->dump_on(st);
 134   }
 135 }
 136 
 137 // For a ParmNode, all immediate inputs and outputs are considered relevant
 138 // both in compact and standard representation.
 139 void ParmNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
 140   this->collect_nodes(in_rel, 1, false, false);
 141   this->collect_nodes(out_rel, -1, false, false);
 142 }
 143 #endif
 144 
 145 uint ParmNode::ideal_reg() const {
 146   switch( _con ) {
 147   case TypeFunc::Control  : // fall through
 148   case TypeFunc::I_O      : // fall through
 149   case TypeFunc::Memory   : return 0;
 150   case TypeFunc::FramePtr : // fall through
 151   case TypeFunc::ReturnAdr: return Op_RegP;
 152   default                 : assert( _con > TypeFunc::Parms, "" );
 153     // fall through
 154   case TypeFunc::Parms    : {
 155     // Type of argument being passed
 156     const Type *t = in(0)->as_Start()->_domain->field_at(_con);
 157     return t->ideal_reg();
 158   }
 159   }
 160   ShouldNotReachHere();
 161   return 0;
 162 }
 163 
 164 //=============================================================================
 165 ReturnNode::ReturnNode(uint edges, Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *retadr ) : Node(edges) {
 166   init_req(TypeFunc::Control,cntrl);
 167   init_req(TypeFunc::I_O,i_o);
 168   init_req(TypeFunc::Memory,memory);
 169   init_req(TypeFunc::FramePtr,frameptr);
 170   init_req(TypeFunc::ReturnAdr,retadr);
 171 }
 172 
 173 Node *ReturnNode::Ideal(PhaseGVN *phase, bool can_reshape){
 174   return remove_dead_region(phase, can_reshape) ? this : NULL;
 175 }
 176 
 177 const Type* ReturnNode::Value(PhaseGVN* phase) const {
 178   return ( phase->type(in(TypeFunc::Control)) == Type::TOP)
 179     ? Type::TOP
 180     : Type::BOTTOM;
 181 }
 182 
 183 // Do we Match on this edge index or not?  No edges on return nodes
 184 uint ReturnNode::match_edge(uint idx) const {
 185   return 0;
 186 }
 187 
 188 
 189 #ifndef PRODUCT
 190 void ReturnNode::dump_req(outputStream *st) const {
 191   // Dump the required inputs, enclosed in '(' and ')'
 192   uint i;                       // Exit value of loop
 193   for (i = 0; i < req(); i++) {    // For all required inputs
 194     if (i == TypeFunc::Parms) st->print("returns");
 195     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 196     else st->print("_ ");
 197   }
 198 }
 199 #endif
 200 
 201 //=============================================================================
 202 RethrowNode::RethrowNode(
 203   Node* cntrl,
 204   Node* i_o,
 205   Node* memory,
 206   Node* frameptr,
 207   Node* ret_adr,
 208   Node* exception
 209 ) : Node(TypeFunc::Parms + 1) {
 210   init_req(TypeFunc::Control  , cntrl    );
 211   init_req(TypeFunc::I_O      , i_o      );
 212   init_req(TypeFunc::Memory   , memory   );
 213   init_req(TypeFunc::FramePtr , frameptr );
 214   init_req(TypeFunc::ReturnAdr, ret_adr);
 215   init_req(TypeFunc::Parms    , exception);
 216 }
 217 
 218 Node *RethrowNode::Ideal(PhaseGVN *phase, bool can_reshape){
 219   return remove_dead_region(phase, can_reshape) ? this : NULL;
 220 }
 221 
 222 const Type* RethrowNode::Value(PhaseGVN* phase) const {
 223   return (phase->type(in(TypeFunc::Control)) == Type::TOP)
 224     ? Type::TOP
 225     : Type::BOTTOM;
 226 }
 227 
 228 uint RethrowNode::match_edge(uint idx) const {
 229   return 0;
 230 }
 231 
 232 #ifndef PRODUCT
 233 void RethrowNode::dump_req(outputStream *st) const {
 234   // Dump the required inputs, enclosed in '(' and ')'
 235   uint i;                       // Exit value of loop
 236   for (i = 0; i < req(); i++) {    // For all required inputs
 237     if (i == TypeFunc::Parms) st->print("exception");
 238     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 239     else st->print("_ ");
 240   }
 241 }
 242 #endif
 243 
 244 //=============================================================================
 245 // Do we Match on this edge index or not?  Match only target address & method
 246 uint TailCallNode::match_edge(uint idx) const {
 247   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 248 }
 249 
 250 //=============================================================================
 251 // Do we Match on this edge index or not?  Match only target address & oop
 252 uint TailJumpNode::match_edge(uint idx) const {
 253   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 254 }
 255 
 256 //=============================================================================
 257 JVMState::JVMState(ciMethod* method, JVMState* caller) :
 258   _method(method) {
 259   assert(method != NULL, "must be valid call site");
 260   _bci = InvocationEntryBci;
 261   _reexecute = Reexecute_Undefined;
 262   debug_only(_bci = -99);  // random garbage value
 263   debug_only(_map = (SafePointNode*)-1);
 264   _caller = caller;
 265   _depth  = 1 + (caller == NULL ? 0 : caller->depth());
 266   _locoff = TypeFunc::Parms;
 267   _stkoff = _locoff + _method->max_locals();
 268   _monoff = _stkoff + _method->max_stack();
 269   _scloff = _monoff;
 270   _endoff = _monoff;
 271   _sp = 0;
 272 }
 273 JVMState::JVMState(int stack_size) :
 274   _method(NULL) {
 275   _bci = InvocationEntryBci;
 276   _reexecute = Reexecute_Undefined;
 277   debug_only(_map = (SafePointNode*)-1);
 278   _caller = NULL;
 279   _depth  = 1;
 280   _locoff = TypeFunc::Parms;
 281   _stkoff = _locoff;
 282   _monoff = _stkoff + stack_size;
 283   _scloff = _monoff;
 284   _endoff = _monoff;
 285   _sp = 0;
 286 }
 287 
 288 //--------------------------------of_depth-------------------------------------
 289 JVMState* JVMState::of_depth(int d) const {
 290   const JVMState* jvmp = this;
 291   assert(0 < d && (uint)d <= depth(), "oob");
 292   for (int skip = depth() - d; skip > 0; skip--) {
 293     jvmp = jvmp->caller();
 294   }
 295   assert(jvmp->depth() == (uint)d, "found the right one");
 296   return (JVMState*)jvmp;
 297 }
 298 
 299 //-----------------------------same_calls_as-----------------------------------
 300 bool JVMState::same_calls_as(const JVMState* that) const {
 301   if (this == that)                    return true;
 302   if (this->depth() != that->depth())  return false;
 303   const JVMState* p = this;
 304   const JVMState* q = that;
 305   for (;;) {
 306     if (p->_method != q->_method)    return false;
 307     if (p->_method == NULL)          return true;   // bci is irrelevant
 308     if (p->_bci    != q->_bci)       return false;
 309     if (p->_reexecute != q->_reexecute)  return false;
 310     p = p->caller();
 311     q = q->caller();
 312     if (p == q)                      return true;
 313     assert(p != NULL && q != NULL, "depth check ensures we don't run off end");
 314   }
 315 }
 316 
 317 //------------------------------debug_start------------------------------------
 318 uint JVMState::debug_start()  const {
 319   debug_only(JVMState* jvmroot = of_depth(1));
 320   assert(jvmroot->locoff() <= this->locoff(), "youngest JVMState must be last");
 321   return of_depth(1)->locoff();
 322 }
 323 
 324 //-------------------------------debug_end-------------------------------------
 325 uint JVMState::debug_end() const {
 326   debug_only(JVMState* jvmroot = of_depth(1));
 327   assert(jvmroot->endoff() <= this->endoff(), "youngest JVMState must be last");
 328   return endoff();
 329 }
 330 
 331 //------------------------------debug_depth------------------------------------
 332 uint JVMState::debug_depth() const {
 333   uint total = 0;
 334   for (const JVMState* jvmp = this; jvmp != NULL; jvmp = jvmp->caller()) {
 335     total += jvmp->debug_size();
 336   }
 337   return total;
 338 }
 339 
 340 #ifndef PRODUCT
 341 
 342 //------------------------------format_helper----------------------------------
 343 // Given an allocation (a Chaitin object) and a Node decide if the Node carries
 344 // any defined value or not.  If it does, print out the register or constant.
 345 static void format_helper( PhaseRegAlloc *regalloc, outputStream* st, Node *n, const char *msg, uint i, GrowableArray<SafePointScalarObjectNode*> *scobjs ) {
 346   if (n == NULL) { st->print(" NULL"); return; }
 347   if (n->is_SafePointScalarObject()) {
 348     // Scalar replacement.
 349     SafePointScalarObjectNode* spobj = n->as_SafePointScalarObject();
 350     scobjs->append_if_missing(spobj);
 351     int sco_n = scobjs->find(spobj);
 352     assert(sco_n >= 0, "");
 353     st->print(" %s%d]=#ScObj" INT32_FORMAT, msg, i, sco_n);
 354     return;
 355   }
 356   if (regalloc->node_regs_max_index() > 0 &&
 357       OptoReg::is_valid(regalloc->get_reg_first(n))) { // Check for undefined
 358     char buf[50];
 359     regalloc->dump_register(n,buf);
 360     st->print(" %s%d]=%s",msg,i,buf);
 361   } else {                      // No register, but might be constant
 362     const Type *t = n->bottom_type();
 363     switch (t->base()) {
 364     case Type::Int:
 365       st->print(" %s%d]=#" INT32_FORMAT,msg,i,t->is_int()->get_con());
 366       break;
 367     case Type::AnyPtr:
 368       assert( t == TypePtr::NULL_PTR || n->in_dump(), "" );
 369       st->print(" %s%d]=#NULL",msg,i);
 370       break;
 371     case Type::AryPtr:
 372     case Type::ValueTypePtr:
 373     case Type::InstPtr:
 374       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->isa_oopptr()->const_oop()));
 375       break;
 376     case Type::KlassPtr:
 377       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_klassptr()->klass()));
 378       break;
 379     case Type::MetadataPtr:
 380       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_metadataptr()->metadata()));
 381       break;
 382     case Type::NarrowOop:
 383       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,p2i(t->make_ptr()->isa_oopptr()->const_oop()));
 384       break;
 385     case Type::RawPtr:
 386       st->print(" %s%d]=#Raw" INTPTR_FORMAT,msg,i,p2i(t->is_rawptr()));
 387       break;
 388     case Type::DoubleCon:
 389       st->print(" %s%d]=#%fD",msg,i,t->is_double_constant()->_d);
 390       break;
 391     case Type::FloatCon:
 392       st->print(" %s%d]=#%fF",msg,i,t->is_float_constant()->_f);
 393       break;
 394     case Type::Long:
 395       st->print(" %s%d]=#" INT64_FORMAT,msg,i,(int64_t)(t->is_long()->get_con()));
 396       break;
 397     case Type::Half:
 398     case Type::Top:
 399       st->print(" %s%d]=_",msg,i);
 400       break;
 401     default: ShouldNotReachHere();
 402     }
 403   }
 404 }
 405 
 406 //------------------------------format-----------------------------------------
 407 void JVMState::format(PhaseRegAlloc *regalloc, const Node *n, outputStream* st) const {
 408   st->print("        #");
 409   if (_method) {
 410     _method->print_short_name(st);
 411     st->print(" @ bci:%d ",_bci);
 412   } else {
 413     st->print_cr(" runtime stub ");
 414     return;
 415   }
 416   if (n->is_MachSafePoint()) {
 417     GrowableArray<SafePointScalarObjectNode*> scobjs;
 418     MachSafePointNode *mcall = n->as_MachSafePoint();
 419     uint i;
 420     // Print locals
 421     for (i = 0; i < (uint)loc_size(); i++)
 422       format_helper(regalloc, st, mcall->local(this, i), "L[", i, &scobjs);
 423     // Print stack
 424     for (i = 0; i < (uint)stk_size(); i++) {
 425       if ((uint)(_stkoff + i) >= mcall->len())
 426         st->print(" oob ");
 427       else
 428        format_helper(regalloc, st, mcall->stack(this, i), "STK[", i, &scobjs);
 429     }
 430     for (i = 0; (int)i < nof_monitors(); i++) {
 431       Node *box = mcall->monitor_box(this, i);
 432       Node *obj = mcall->monitor_obj(this, i);
 433       if (regalloc->node_regs_max_index() > 0 &&
 434           OptoReg::is_valid(regalloc->get_reg_first(box))) {
 435         box = BoxLockNode::box_node(box);
 436         format_helper(regalloc, st, box, "MON-BOX[", i, &scobjs);
 437       } else {
 438         OptoReg::Name box_reg = BoxLockNode::reg(box);
 439         st->print(" MON-BOX%d=%s+%d",
 440                    i,
 441                    OptoReg::regname(OptoReg::c_frame_pointer),
 442                    regalloc->reg2offset(box_reg));
 443       }
 444       const char* obj_msg = "MON-OBJ[";
 445       if (EliminateLocks) {
 446         if (BoxLockNode::box_node(box)->is_eliminated())
 447           obj_msg = "MON-OBJ(LOCK ELIMINATED)[";
 448       }
 449       format_helper(regalloc, st, obj, obj_msg, i, &scobjs);
 450     }
 451 
 452     for (i = 0; i < (uint)scobjs.length(); i++) {
 453       // Scalar replaced objects.
 454       st->cr();
 455       st->print("        # ScObj" INT32_FORMAT " ", i);
 456       SafePointScalarObjectNode* spobj = scobjs.at(i);
 457       ciKlass* cik = spobj->bottom_type()->is_oopptr()->klass();
 458       assert(cik->is_instance_klass() ||
 459              cik->is_array_klass(), "Not supported allocation.");
 460       ciInstanceKlass *iklass = NULL;
 461       if (cik->is_instance_klass()) {
 462         cik->print_name_on(st);
 463         iklass = cik->as_instance_klass();
 464       } else if (cik->is_type_array_klass()) {
 465         cik->as_array_klass()->base_element_type()->print_name_on(st);
 466         st->print("[%d]", spobj->n_fields());
 467       } else if (cik->is_obj_array_klass()) {
 468         ciKlass* cie = cik->as_obj_array_klass()->base_element_klass();
 469         if (cie->is_instance_klass()) {
 470           cie->print_name_on(st);
 471         } else if (cie->is_type_array_klass()) {
 472           cie->as_array_klass()->base_element_type()->print_name_on(st);
 473         } else {
 474           ShouldNotReachHere();
 475         }
 476         st->print("[%d]", spobj->n_fields());
 477         int ndim = cik->as_array_klass()->dimension() - 1;
 478         while (ndim-- > 0) {
 479           st->print("[]");
 480         }
 481       }
 482       st->print("={");
 483       uint nf = spobj->n_fields();
 484       if (nf > 0) {
 485         uint first_ind = spobj->first_index(mcall->jvms());
 486         Node* fld_node = mcall->in(first_ind);
 487         ciField* cifield;
 488         if (iklass != NULL) {
 489           st->print(" [");
 490           cifield = iklass->nonstatic_field_at(0);
 491           cifield->print_name_on(st);
 492           format_helper(regalloc, st, fld_node, ":", 0, &scobjs);
 493         } else {
 494           format_helper(regalloc, st, fld_node, "[", 0, &scobjs);
 495         }
 496         for (uint j = 1; j < nf; j++) {
 497           fld_node = mcall->in(first_ind+j);
 498           if (iklass != NULL) {
 499             st->print(", [");
 500             cifield = iklass->nonstatic_field_at(j);
 501             cifield->print_name_on(st);
 502             format_helper(regalloc, st, fld_node, ":", j, &scobjs);
 503           } else {
 504             format_helper(regalloc, st, fld_node, ", [", j, &scobjs);
 505           }
 506         }
 507       }
 508       st->print(" }");
 509     }
 510   }
 511   st->cr();
 512   if (caller() != NULL) caller()->format(regalloc, n, st);
 513 }
 514 
 515 
 516 void JVMState::dump_spec(outputStream *st) const {
 517   if (_method != NULL) {
 518     bool printed = false;
 519     if (!Verbose) {
 520       // The JVMS dumps make really, really long lines.
 521       // Take out the most boring parts, which are the package prefixes.
 522       char buf[500];
 523       stringStream namest(buf, sizeof(buf));
 524       _method->print_short_name(&namest);
 525       if (namest.count() < sizeof(buf)) {
 526         const char* name = namest.base();
 527         if (name[0] == ' ')  ++name;
 528         const char* endcn = strchr(name, ':');  // end of class name
 529         if (endcn == NULL)  endcn = strchr(name, '(');
 530         if (endcn == NULL)  endcn = name + strlen(name);
 531         while (endcn > name && endcn[-1] != '.' && endcn[-1] != '/')
 532           --endcn;
 533         st->print(" %s", endcn);
 534         printed = true;
 535       }
 536     }
 537     if (!printed)
 538       _method->print_short_name(st);
 539     st->print(" @ bci:%d",_bci);
 540     if(_reexecute == Reexecute_True)
 541       st->print(" reexecute");
 542   } else {
 543     st->print(" runtime stub");
 544   }
 545   if (caller() != NULL)  caller()->dump_spec(st);
 546 }
 547 
 548 
 549 void JVMState::dump_on(outputStream* st) const {
 550   bool print_map = _map && !((uintptr_t)_map & 1) &&
 551                   ((caller() == NULL) || (caller()->map() != _map));
 552   if (print_map) {
 553     if (_map->len() > _map->req()) {  // _map->has_exceptions()
 554       Node* ex = _map->in(_map->req());  // _map->next_exception()
 555       // skip the first one; it's already being printed
 556       while (ex != NULL && ex->len() > ex->req()) {
 557         ex = ex->in(ex->req());  // ex->next_exception()
 558         ex->dump(1);
 559       }
 560     }
 561     _map->dump(Verbose ? 2 : 1);
 562   }
 563   if (caller() != NULL) {
 564     caller()->dump_on(st);
 565   }
 566   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=",
 567              depth(), locoff(), stkoff(), argoff(), monoff(), scloff(), endoff(), monitor_depth(), sp(), bci(), should_reexecute()?"true":"false");
 568   if (_method == NULL) {
 569     st->print_cr("(none)");
 570   } else {
 571     _method->print_name(st);
 572     st->cr();
 573     if (bci() >= 0 && bci() < _method->code_size()) {
 574       st->print("    bc: ");
 575       _method->print_codes_on(bci(), bci()+1, st);
 576     }
 577   }
 578 }
 579 
 580 // Extra way to dump a jvms from the debugger,
 581 // to avoid a bug with C++ member function calls.
 582 void dump_jvms(JVMState* jvms) {
 583   jvms->dump();
 584 }
 585 #endif
 586 
 587 //--------------------------clone_shallow--------------------------------------
 588 JVMState* JVMState::clone_shallow(Compile* C) const {
 589   JVMState* n = has_method() ? new (C) JVMState(_method, _caller) : new (C) JVMState(0);
 590   n->set_bci(_bci);
 591   n->_reexecute = _reexecute;
 592   n->set_locoff(_locoff);
 593   n->set_stkoff(_stkoff);
 594   n->set_monoff(_monoff);
 595   n->set_scloff(_scloff);
 596   n->set_endoff(_endoff);
 597   n->set_sp(_sp);
 598   n->set_map(_map);
 599   return n;
 600 }
 601 
 602 //---------------------------clone_deep----------------------------------------
 603 JVMState* JVMState::clone_deep(Compile* C) const {
 604   JVMState* n = clone_shallow(C);
 605   for (JVMState* p = n; p->_caller != NULL; p = p->_caller) {
 606     p->_caller = p->_caller->clone_shallow(C);
 607   }
 608   assert(n->depth() == depth(), "sanity");
 609   assert(n->debug_depth() == debug_depth(), "sanity");
 610   return n;
 611 }
 612 
 613 /**
 614  * Reset map for all callers
 615  */
 616 void JVMState::set_map_deep(SafePointNode* map) {
 617   for (JVMState* p = this; p->_caller != NULL; p = p->_caller) {
 618     p->set_map(map);
 619   }
 620 }
 621 
 622 // Adapt offsets in in-array after adding or removing an edge.
 623 // Prerequisite is that the JVMState is used by only one node.
 624 void JVMState::adapt_position(int delta) {
 625   for (JVMState* jvms = this; jvms != NULL; jvms = jvms->caller()) {
 626     jvms->set_locoff(jvms->locoff() + delta);
 627     jvms->set_stkoff(jvms->stkoff() + delta);
 628     jvms->set_monoff(jvms->monoff() + delta);
 629     jvms->set_scloff(jvms->scloff() + delta);
 630     jvms->set_endoff(jvms->endoff() + delta);
 631   }
 632 }
 633 
 634 // Mirror the stack size calculation in the deopt code
 635 // How much stack space would we need at this point in the program in
 636 // case of deoptimization?
 637 int JVMState::interpreter_frame_size() const {
 638   const JVMState* jvms = this;
 639   int size = 0;
 640   int callee_parameters = 0;
 641   int callee_locals = 0;
 642   int extra_args = method()->max_stack() - stk_size();
 643 
 644   while (jvms != NULL) {
 645     int locks = jvms->nof_monitors();
 646     int temps = jvms->stk_size();
 647     bool is_top_frame = (jvms == this);
 648     ciMethod* method = jvms->method();
 649 
 650     int frame_size = BytesPerWord * Interpreter::size_activation(method->max_stack(),
 651                                                                  temps + callee_parameters,
 652                                                                  extra_args,
 653                                                                  locks,
 654                                                                  callee_parameters,
 655                                                                  callee_locals,
 656                                                                  is_top_frame);
 657     size += frame_size;
 658 
 659     callee_parameters = method->size_of_parameters();
 660     callee_locals = method->max_locals();
 661     extra_args = 0;
 662     jvms = jvms->caller();
 663   }
 664   return size + Deoptimization::last_frame_adjust(0, callee_locals) * BytesPerWord;
 665 }
 666 
 667 //=============================================================================
 668 uint CallNode::cmp( const Node &n ) const
 669 { return _tf == ((CallNode&)n)._tf && _jvms == ((CallNode&)n)._jvms; }
 670 #ifndef PRODUCT
 671 void CallNode::dump_req(outputStream *st) const {
 672   // Dump the required inputs, enclosed in '(' and ')'
 673   uint i;                       // Exit value of loop
 674   for (i = 0; i < req(); i++) {    // For all required inputs
 675     if (i == TypeFunc::Parms) st->print("(");
 676     if (in(i)) st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
 677     else st->print("_ ");
 678   }
 679   st->print(")");
 680 }
 681 
 682 void CallNode::dump_spec(outputStream *st) const {
 683   st->print(" ");
 684   if (tf() != NULL)  tf()->dump_on(st);
 685   if (_cnt != COUNT_UNKNOWN)  st->print(" C=%f",_cnt);
 686   if (jvms() != NULL)  jvms()->dump_spec(st);
 687 }
 688 #endif
 689 
 690 const Type *CallNode::bottom_type() const { return tf()->range(); }
 691 const Type* CallNode::Value(PhaseGVN* phase) const {
 692   if (phase->type(in(0)) == Type::TOP)  return Type::TOP;
 693   return tf()->range();
 694 }
 695 
 696 //------------------------------calling_convention-----------------------------
 697 void CallNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
 698   // Use the standard compiler calling convention
 699   Matcher::calling_convention( sig_bt, parm_regs, argcnt, true );
 700 }
 701 
 702 
 703 //------------------------------match------------------------------------------
 704 // Construct projections for control, I/O, memory-fields, ..., and
 705 // return result(s) along with their RegMask info
 706 Node *CallNode::match( const ProjNode *proj, const Matcher *match ) {
 707   switch (proj->_con) {
 708   case TypeFunc::Control:
 709   case TypeFunc::I_O:
 710   case TypeFunc::Memory:
 711     return new MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
 712 
 713   case TypeFunc::Parms+1:       // For LONG & DOUBLE returns
 714     assert(tf()->range()->field_at(TypeFunc::Parms+1) == Type::HALF, "");
 715     // 2nd half of doubles and longs
 716     return new MachProjNode(this,proj->_con, RegMask::Empty, (uint)OptoReg::Bad);
 717 
 718   case TypeFunc::Parms: {       // Normal returns
 719     uint ideal_reg = tf()->range()->field_at(TypeFunc::Parms)->ideal_reg();
 720     OptoRegPair regs = is_CallRuntime()
 721       ? match->c_return_value(ideal_reg,true)  // Calls into C runtime
 722       : match->  return_value(ideal_reg,true); // Calls into compiled Java code
 723     RegMask rm = RegMask(regs.first());
 724     if( OptoReg::is_valid(regs.second()) )
 725       rm.Insert( regs.second() );
 726     return new MachProjNode(this,proj->_con,rm,ideal_reg);
 727   }
 728 
 729   case TypeFunc::ReturnAdr:
 730   case TypeFunc::FramePtr:
 731   default:
 732     ShouldNotReachHere();
 733   }
 734   return NULL;
 735 }
 736 
 737 // Do we Match on this edge index or not?  Match no edges
 738 uint CallNode::match_edge(uint idx) const {
 739   return 0;
 740 }
 741 
 742 //
 743 // Determine whether the call could modify the field of the specified
 744 // instance at the specified offset.
 745 //
 746 bool CallNode::may_modify(const TypeOopPtr *t_oop, PhaseTransform *phase) {
 747   assert((t_oop != NULL), "sanity");
 748   if (is_call_to_arraycopystub() && strcmp(_name, "unsafe_arraycopy") != 0) {
 749     const TypeTuple* args = _tf->domain_sig();
 750     Node* dest = NULL;
 751     // Stubs that can be called once an ArrayCopyNode is expanded have
 752     // different signatures. Look for the second pointer argument,
 753     // that is the destination of the copy.
 754     for (uint i = TypeFunc::Parms, j = 0; i < args->cnt(); i++) {
 755       if (args->field_at(i)->isa_ptr()) {
 756         j++;
 757         if (j == 2) {
 758           dest = in(i);
 759           break;
 760         }
 761       }
 762     }
 763     if (!dest->is_top() && may_modify_arraycopy_helper(phase->type(dest)->is_oopptr(), t_oop, phase)) {
 764       return true;
 765     }
 766     return false;
 767   }
 768   if (t_oop->is_known_instance()) {
 769     // The instance_id is set only for scalar-replaceable allocations which
 770     // are not passed as arguments according to Escape Analysis.
 771     return false;
 772   }
 773   if (t_oop->is_ptr_to_boxed_value()) {
 774     ciKlass* boxing_klass = t_oop->klass();
 775     if (is_CallStaticJava() && as_CallStaticJava()->is_boxing_method()) {
 776       // Skip unrelated boxing methods.
 777       Node* proj = proj_out(TypeFunc::Parms);
 778       if ((proj == NULL) || (phase->type(proj)->is_instptr()->klass() != boxing_klass)) {
 779         return false;
 780       }
 781     }
 782     if (is_CallJava() && as_CallJava()->method() != NULL) {
 783       ciMethod* meth = as_CallJava()->method();
 784       if (meth->is_getter()) {
 785         return false;
 786       }
 787       // May modify (by reflection) if an boxing object is passed
 788       // as argument or returned.
 789       if (returns_pointer() && (proj_out(TypeFunc::Parms) != NULL)) {
 790         Node* proj = proj_out(TypeFunc::Parms);
 791         const TypeInstPtr* inst_t = phase->type(proj)->isa_instptr();
 792         if ((inst_t != NULL) && (!inst_t->klass_is_exact() ||
 793                                  (inst_t->klass() == boxing_klass))) {
 794           return true;
 795         }
 796       }
 797       const TypeTuple* d = tf()->domain_cc();
 798       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 799         const TypeInstPtr* inst_t = d->field_at(i)->isa_instptr();
 800         if ((inst_t != NULL) && (!inst_t->klass_is_exact() ||
 801                                  (inst_t->klass() == boxing_klass))) {
 802           return true;
 803         }
 804       }
 805       return false;
 806     }
 807   }
 808   return true;
 809 }
 810 
 811 // Does this call have a direct reference to n other than debug information?
 812 bool CallNode::has_non_debug_use(Node *n) {
 813   const TypeTuple * d = tf()->domain_cc();
 814   for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 815     Node *arg = in(i);
 816     if (arg == n) {
 817       return true;
 818     }
 819   }
 820   return false;
 821 }
 822 
 823 bool CallNode::has_debug_use(Node *n) {
 824   for (uint i = jvms()->debug_start(); i < jvms()->debug_end(); i++) {
 825     Node *arg = in(i);
 826     if (arg == n) {
 827       return true;
 828     }
 829   }
 830   return false;
 831 }
 832 
 833 // Returns the unique CheckCastPP of a call
 834 // or 'this' if there are several CheckCastPP or unexpected uses
 835 // or returns NULL if there is no one.
 836 Node *CallNode::result_cast() {
 837   Node *cast = NULL;
 838 
 839   Node *p = proj_out(TypeFunc::Parms);
 840   if (p == NULL)
 841     return NULL;
 842 
 843   for (DUIterator_Fast imax, i = p->fast_outs(imax); i < imax; i++) {
 844     Node *use = p->fast_out(i);
 845     if (use->is_CheckCastPP()) {
 846       if (cast != NULL) {
 847         return this;  // more than 1 CheckCastPP
 848       }
 849       cast = use;
 850     } else if (!use->is_Initialize() &&
 851                !use->is_AddP() &&
 852                use->Opcode() != Op_MemBarStoreStore) {
 853       // Expected uses are restricted to a CheckCastPP, an Initialize
 854       // node, a MemBarStoreStore (clone) and AddP nodes. If we
 855       // encounter any other use (a Phi node can be seen in rare
 856       // cases) return this to prevent incorrect optimizations.
 857       return this;
 858     }
 859   }
 860   return cast;
 861 }
 862 
 863 
 864 void CallNode::extract_projections(CallProjections* projs, bool separate_io_proj, bool do_asserts) {
 865   projs->fallthrough_proj      = NULL;
 866   projs->fallthrough_catchproj = NULL;
 867   projs->fallthrough_ioproj    = NULL;
 868   projs->catchall_ioproj       = NULL;
 869   projs->catchall_catchproj    = NULL;
 870   projs->fallthrough_memproj   = NULL;
 871   projs->catchall_memproj      = NULL;
 872   projs->resproj               = NULL;
 873   projs->exobj                 = NULL;
 874 
 875   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 876     ProjNode *pn = fast_out(i)->as_Proj();
 877     if (pn->outcnt() == 0) continue;
 878     switch (pn->_con) {
 879     case TypeFunc::Control:
 880       {
 881         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 882         projs->fallthrough_proj = pn;
 883         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 884         const Node *cn = pn->fast_out(j);
 885         if (cn->is_Catch()) {
 886           ProjNode *cpn = NULL;
 887           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 888             cpn = cn->fast_out(k)->as_Proj();
 889             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 890             if (cpn->_con == CatchProjNode::fall_through_index)
 891               projs->fallthrough_catchproj = cpn;
 892             else {
 893               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 894               projs->catchall_catchproj = cpn;
 895             }
 896           }
 897         }
 898         break;
 899       }
 900     case TypeFunc::I_O:
 901       if (pn->_is_io_use)
 902         projs->catchall_ioproj = pn;
 903       else
 904         projs->fallthrough_ioproj = pn;
 905       for (DUIterator j = pn->outs(); pn->has_out(j); j++) {
 906         Node* e = pn->out(j);
 907         if (e->Opcode() == Op_CreateEx && e->in(0)->is_CatchProj() && e->outcnt() > 0) {
 908           assert(projs->exobj == NULL, "only one");
 909           projs->exobj = e;
 910         }
 911       }
 912       break;
 913     case TypeFunc::Memory:
 914       if (pn->_is_io_use)
 915         projs->catchall_memproj = pn;
 916       else
 917         projs->fallthrough_memproj = pn;
 918       break;
 919     case TypeFunc::Parms:
 920       projs->resproj = pn;
 921       break;
 922     default:
 923       assert(false, "unexpected projection from allocation node.");
 924     }
 925   }
 926 
 927   // The resproj may not exist because the result could be ignored
 928   // and the exception object may not exist if an exception handler
 929   // swallows the exception but all the other must exist and be found.
 930   assert(projs->fallthrough_proj      != NULL, "must be found");
 931   do_asserts = do_asserts && !Compile::current()->inlining_incrementally();
 932   assert(!do_asserts || projs->fallthrough_catchproj != NULL, "must be found");
 933   assert(!do_asserts || projs->fallthrough_memproj   != NULL, "must be found");
 934   assert(!do_asserts || projs->fallthrough_ioproj    != NULL, "must be found");
 935   assert(!do_asserts || projs->catchall_catchproj    != NULL, "must be found");
 936   if (separate_io_proj) {
 937     assert(!do_asserts || projs->catchall_memproj    != NULL, "must be found");
 938     assert(!do_asserts || projs->catchall_ioproj     != NULL, "must be found");
 939   }
 940 }
 941 
 942 Node *CallNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 943   CallGenerator* cg = generator();
 944   if (can_reshape && cg != NULL && cg->is_mh_late_inline() && !cg->already_attempted()) {
 945     // Check whether this MH handle call becomes a candidate for inlining
 946     ciMethod* callee = cg->method();
 947     vmIntrinsics::ID iid = callee->intrinsic_id();
 948     if (iid == vmIntrinsics::_invokeBasic) {
 949       if (in(TypeFunc::Parms)->Opcode() == Op_ConP) {
 950         phase->C->prepend_late_inline(cg);
 951         set_generator(NULL);
 952       }
 953     } else {
 954       assert(callee->has_member_arg(), "wrong type of call?");
 955       if (in(TypeFunc::Parms + callee->arg_size() - 1)->Opcode() == Op_ConP) {
 956         phase->C->prepend_late_inline(cg);
 957         set_generator(NULL);
 958       }
 959     }
 960   }
 961   return SafePointNode::Ideal(phase, can_reshape);
 962 }
 963 
 964 bool CallNode::is_call_to_arraycopystub() const {
 965   if (_name != NULL && strstr(_name, "arraycopy") != 0) {
 966     return true;
 967   }
 968   return false;
 969 }
 970 
 971 //=============================================================================
 972 uint CallJavaNode::size_of() const { return sizeof(*this); }
 973 uint CallJavaNode::cmp( const Node &n ) const {
 974   CallJavaNode &call = (CallJavaNode&)n;
 975   return CallNode::cmp(call) && _method == call._method &&
 976          _override_symbolic_info == call._override_symbolic_info;
 977 }
 978 #ifndef PRODUCT
 979 void CallJavaNode::dump_spec(outputStream *st) const {
 980   if( _method ) _method->print_short_name(st);
 981   CallNode::dump_spec(st);
 982 }
 983 
 984 void CallJavaNode::dump_compact_spec(outputStream* st) const {
 985   if (_method) {
 986     _method->print_short_name(st);
 987   } else {
 988     st->print("<?>");
 989   }
 990 }
 991 #endif
 992 
 993 //=============================================================================
 994 uint CallStaticJavaNode::size_of() const { return sizeof(*this); }
 995 uint CallStaticJavaNode::cmp( const Node &n ) const {
 996   CallStaticJavaNode &call = (CallStaticJavaNode&)n;
 997   return CallJavaNode::cmp(call);
 998 }
 999 
1000 //----------------------------uncommon_trap_request----------------------------
1001 // If this is an uncommon trap, return the request code, else zero.
1002 int CallStaticJavaNode::uncommon_trap_request() const {
1003   if (_name != NULL && !strcmp(_name, "uncommon_trap")) {
1004     return extract_uncommon_trap_request(this);
1005   }
1006   return 0;
1007 }
1008 int CallStaticJavaNode::extract_uncommon_trap_request(const Node* call) {
1009 #ifndef PRODUCT
1010   if (!(call->req() > TypeFunc::Parms &&
1011         call->in(TypeFunc::Parms) != NULL &&
1012         call->in(TypeFunc::Parms)->is_Con() &&
1013         call->in(TypeFunc::Parms)->bottom_type()->isa_int())) {
1014     assert(in_dump() != 0, "OK if dumping");
1015     tty->print("[bad uncommon trap]");
1016     return 0;
1017   }
1018 #endif
1019   return call->in(TypeFunc::Parms)->bottom_type()->is_int()->get_con();
1020 }
1021 
1022 #ifndef PRODUCT
1023 void CallStaticJavaNode::dump_spec(outputStream *st) const {
1024   st->print("# Static ");
1025   if (_name != NULL) {
1026     st->print("%s", _name);
1027     int trap_req = uncommon_trap_request();
1028     if (trap_req != 0) {
1029       char buf[100];
1030       st->print("(%s)",
1031                  Deoptimization::format_trap_request(buf, sizeof(buf),
1032                                                      trap_req));
1033     }
1034     st->print(" ");
1035   }
1036   CallJavaNode::dump_spec(st);
1037 }
1038 
1039 void CallStaticJavaNode::dump_compact_spec(outputStream* st) const {
1040   if (_method) {
1041     _method->print_short_name(st);
1042   } else if (_name) {
1043     st->print("%s", _name);
1044   } else {
1045     st->print("<?>");
1046   }
1047 }
1048 #endif
1049 
1050 //=============================================================================
1051 uint CallDynamicJavaNode::size_of() const { return sizeof(*this); }
1052 uint CallDynamicJavaNode::cmp( const Node &n ) const {
1053   CallDynamicJavaNode &call = (CallDynamicJavaNode&)n;
1054   return CallJavaNode::cmp(call);
1055 }
1056 #ifndef PRODUCT
1057 void CallDynamicJavaNode::dump_spec(outputStream *st) const {
1058   st->print("# Dynamic ");
1059   CallJavaNode::dump_spec(st);
1060 }
1061 #endif
1062 
1063 //=============================================================================
1064 uint CallRuntimeNode::size_of() const { return sizeof(*this); }
1065 uint CallRuntimeNode::cmp( const Node &n ) const {
1066   CallRuntimeNode &call = (CallRuntimeNode&)n;
1067   return CallNode::cmp(call) && !strcmp(_name,call._name);
1068 }
1069 #ifndef PRODUCT
1070 void CallRuntimeNode::dump_spec(outputStream *st) const {
1071   st->print("# ");
1072   st->print("%s", _name);
1073   CallNode::dump_spec(st);
1074 }
1075 #endif
1076 
1077 //------------------------------calling_convention-----------------------------
1078 void CallRuntimeNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
1079   Matcher::c_calling_convention( sig_bt, parm_regs, argcnt );
1080 }
1081 
1082 //=============================================================================
1083 //------------------------------calling_convention-----------------------------
1084 
1085 
1086 //=============================================================================
1087 #ifndef PRODUCT
1088 void CallLeafNode::dump_spec(outputStream *st) const {
1089   st->print("# ");
1090   st->print("%s", _name);
1091   CallNode::dump_spec(st);
1092 }
1093 #endif
1094 
1095 //=============================================================================
1096 
1097 void SafePointNode::set_local(JVMState* jvms, uint idx, Node *c) {
1098   assert(verify_jvms(jvms), "jvms must match");
1099   int loc = jvms->locoff() + idx;
1100   if (in(loc)->is_top() && idx > 0 && !c->is_top() ) {
1101     // If current local idx is top then local idx - 1 could
1102     // be a long/double that needs to be killed since top could
1103     // represent the 2nd half ofthe long/double.
1104     uint ideal = in(loc -1)->ideal_reg();
1105     if (ideal == Op_RegD || ideal == Op_RegL) {
1106       // set other (low index) half to top
1107       set_req(loc - 1, in(loc));
1108     }
1109   }
1110   set_req(loc, c);
1111 }
1112 
1113 uint SafePointNode::size_of() const { return sizeof(*this); }
1114 uint SafePointNode::cmp( const Node &n ) const {
1115   return (&n == this);          // Always fail except on self
1116 }
1117 
1118 //-------------------------set_next_exception----------------------------------
1119 void SafePointNode::set_next_exception(SafePointNode* n) {
1120   assert(n == NULL || n->Opcode() == Op_SafePoint, "correct value for next_exception");
1121   if (len() == req()) {
1122     if (n != NULL)  add_prec(n);
1123   } else {
1124     set_prec(req(), n);
1125   }
1126 }
1127 
1128 
1129 //----------------------------next_exception-----------------------------------
1130 SafePointNode* SafePointNode::next_exception() const {
1131   if (len() == req()) {
1132     return NULL;
1133   } else {
1134     Node* n = in(req());
1135     assert(n == NULL || n->Opcode() == Op_SafePoint, "no other uses of prec edges");
1136     return (SafePointNode*) n;
1137   }
1138 }
1139 
1140 
1141 //------------------------------Ideal------------------------------------------
1142 // Skip over any collapsed Regions
1143 Node *SafePointNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1144   if (remove_dead_region(phase, can_reshape)) {
1145     return this;
1146   }
1147   if (jvms() != NULL) {
1148     bool progress = false;
1149     // A ValueTypeNode that was already heap allocated in the debug
1150     // info?  Reference the object directly. Helps removal of useless
1151     // value type allocations with incremental inlining.
1152     for (uint i = jvms()->debug_start(); i < jvms()->debug_end(); i++) {
1153       Node *arg = in(i);
1154       if (arg->is_ValueType()) {
1155         ValueTypeNode* vt = arg->as_ValueType();
1156         Node* in_oop = vt->get_oop();
1157         const Type* oop_type = phase->type(in_oop);
1158         if (!TypePtr::NULL_PTR->higher_equal(oop_type)) {
1159           set_req(i, in_oop);
1160           progress = true;
1161         }
1162       }
1163     }
1164     if (progress) {
1165       return this;
1166     }
1167   }
1168   return NULL;
1169 }
1170 
1171 //------------------------------Identity---------------------------------------
1172 // Remove obviously duplicate safepoints
1173 Node* SafePointNode::Identity(PhaseGVN* phase) {
1174 
1175   // If you have back to back safepoints, remove one
1176   if( in(TypeFunc::Control)->is_SafePoint() )
1177     return in(TypeFunc::Control);
1178 
1179   if( in(0)->is_Proj() ) {
1180     Node *n0 = in(0)->in(0);
1181     // Check if he is a call projection (except Leaf Call)
1182     if( n0->is_Catch() ) {
1183       n0 = n0->in(0)->in(0);
1184       assert( n0->is_Call(), "expect a call here" );
1185     }
1186     if( n0->is_Call() && n0->as_Call()->guaranteed_safepoint() ) {
1187       // Useless Safepoint, so remove it
1188       return in(TypeFunc::Control);
1189     }
1190   }
1191 
1192   return this;
1193 }
1194 
1195 //------------------------------Value------------------------------------------
1196 const Type* SafePointNode::Value(PhaseGVN* phase) const {
1197   if( phase->type(in(0)) == Type::TOP ) return Type::TOP;
1198   if( phase->eqv( in(0), this ) ) return Type::TOP; // Dead infinite loop
1199   return Type::CONTROL;
1200 }
1201 
1202 #ifndef PRODUCT
1203 void SafePointNode::dump_spec(outputStream *st) const {
1204   st->print(" SafePoint ");
1205   _replaced_nodes.dump(st);
1206 }
1207 
1208 // The related nodes of a SafepointNode are all data inputs, excluding the
1209 // control boundary, as well as all outputs till level 2 (to include projection
1210 // nodes and targets). In compact mode, just include inputs till level 1 and
1211 // outputs as before.
1212 void SafePointNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1213   if (compact) {
1214     this->collect_nodes(in_rel, 1, false, false);
1215   } else {
1216     this->collect_nodes_in_all_data(in_rel, false);
1217   }
1218   this->collect_nodes(out_rel, -2, false, false);
1219 }
1220 #endif
1221 
1222 const RegMask &SafePointNode::in_RegMask(uint idx) const {
1223   if( idx < TypeFunc::Parms ) return RegMask::Empty;
1224   // Values outside the domain represent debug info
1225   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
1226 }
1227 const RegMask &SafePointNode::out_RegMask() const {
1228   return RegMask::Empty;
1229 }
1230 
1231 
1232 void SafePointNode::grow_stack(JVMState* jvms, uint grow_by) {
1233   assert((int)grow_by > 0, "sanity");
1234   int monoff = jvms->monoff();
1235   int scloff = jvms->scloff();
1236   int endoff = jvms->endoff();
1237   assert(endoff == (int)req(), "no other states or debug info after me");
1238   Node* top = Compile::current()->top();
1239   for (uint i = 0; i < grow_by; i++) {
1240     ins_req(monoff, top);
1241   }
1242   jvms->set_monoff(monoff + grow_by);
1243   jvms->set_scloff(scloff + grow_by);
1244   jvms->set_endoff(endoff + grow_by);
1245 }
1246 
1247 void SafePointNode::push_monitor(const FastLockNode *lock) {
1248   // Add a LockNode, which points to both the original BoxLockNode (the
1249   // stack space for the monitor) and the Object being locked.
1250   const int MonitorEdges = 2;
1251   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
1252   assert(req() == jvms()->endoff(), "correct sizing");
1253   int nextmon = jvms()->scloff();
1254   if (GenerateSynchronizationCode) {
1255     ins_req(nextmon,   lock->box_node());
1256     ins_req(nextmon+1, lock->obj_node());
1257   } else {
1258     Node* top = Compile::current()->top();
1259     ins_req(nextmon, top);
1260     ins_req(nextmon, top);
1261   }
1262   jvms()->set_scloff(nextmon + MonitorEdges);
1263   jvms()->set_endoff(req());
1264 }
1265 
1266 void SafePointNode::pop_monitor() {
1267   // Delete last monitor from debug info
1268   debug_only(int num_before_pop = jvms()->nof_monitors());
1269   const int MonitorEdges = 2;
1270   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
1271   int scloff = jvms()->scloff();
1272   int endoff = jvms()->endoff();
1273   int new_scloff = scloff - MonitorEdges;
1274   int new_endoff = endoff - MonitorEdges;
1275   jvms()->set_scloff(new_scloff);
1276   jvms()->set_endoff(new_endoff);
1277   while (scloff > new_scloff)  del_req_ordered(--scloff);
1278   assert(jvms()->nof_monitors() == num_before_pop-1, "");
1279 }
1280 
1281 Node *SafePointNode::peek_monitor_box() const {
1282   int mon = jvms()->nof_monitors() - 1;
1283   assert(mon >= 0, "must have a monitor");
1284   return monitor_box(jvms(), mon);
1285 }
1286 
1287 Node *SafePointNode::peek_monitor_obj() const {
1288   int mon = jvms()->nof_monitors() - 1;
1289   assert(mon >= 0, "must have a monitor");
1290   return monitor_obj(jvms(), mon);
1291 }
1292 
1293 // Do we Match on this edge index or not?  Match no edges
1294 uint SafePointNode::match_edge(uint idx) const {
1295   if( !needs_polling_address_input() )
1296     return 0;
1297 
1298   return (TypeFunc::Parms == idx);
1299 }
1300 
1301 //==============  SafePointScalarObjectNode  ==============
1302 
1303 SafePointScalarObjectNode::SafePointScalarObjectNode(const TypeOopPtr* tp,
1304 #ifdef ASSERT
1305                                                      AllocateNode* alloc,
1306 #endif
1307                                                      uint first_index,
1308                                                      uint n_fields) :
1309   TypeNode(tp, 1), // 1 control input -- seems required.  Get from root.
1310 #ifdef ASSERT
1311   _alloc(alloc),
1312 #endif
1313   _first_index(first_index),
1314   _n_fields(n_fields)
1315 {
1316   init_class_id(Class_SafePointScalarObject);
1317 }
1318 
1319 // Do not allow value-numbering for SafePointScalarObject node.
1320 uint SafePointScalarObjectNode::hash() const { return NO_HASH; }
1321 uint SafePointScalarObjectNode::cmp( const Node &n ) const {
1322   return (&n == this); // Always fail except on self
1323 }
1324 
1325 uint SafePointScalarObjectNode::ideal_reg() const {
1326   return 0; // No matching to machine instruction
1327 }
1328 
1329 const RegMask &SafePointScalarObjectNode::in_RegMask(uint idx) const {
1330   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
1331 }
1332 
1333 const RegMask &SafePointScalarObjectNode::out_RegMask() const {
1334   return RegMask::Empty;
1335 }
1336 
1337 uint SafePointScalarObjectNode::match_edge(uint idx) const {
1338   return 0;
1339 }
1340 
1341 SafePointScalarObjectNode*
1342 SafePointScalarObjectNode::clone(Dict* sosn_map) const {
1343   void* cached = (*sosn_map)[(void*)this];
1344   if (cached != NULL) {
1345     return (SafePointScalarObjectNode*)cached;
1346   }
1347   SafePointScalarObjectNode* res = (SafePointScalarObjectNode*)Node::clone();
1348   sosn_map->Insert((void*)this, (void*)res);
1349   return res;
1350 }
1351 
1352 
1353 #ifndef PRODUCT
1354 void SafePointScalarObjectNode::dump_spec(outputStream *st) const {
1355   st->print(" # fields@[%d..%d]", first_index(),
1356              first_index() + n_fields() - 1);
1357 }
1358 
1359 #endif
1360 
1361 //=============================================================================
1362 uint AllocateNode::size_of() const { return sizeof(*this); }
1363 
1364 AllocateNode::AllocateNode(Compile* C, const TypeFunc *atype,
1365                            Node *ctrl, Node *mem, Node *abio,
1366                            Node *size, Node *klass_node, Node *initial_test)
1367   : CallNode(atype, NULL, TypeRawPtr::BOTTOM)
1368 {
1369   init_class_id(Class_Allocate);
1370   init_flags(Flag_is_macro);
1371   _is_scalar_replaceable = false;
1372   _is_non_escaping = false;
1373   _is_allocation_MemBar_redundant = false;
1374   Node *topnode = C->top();
1375 
1376   init_req( TypeFunc::Control  , ctrl );
1377   init_req( TypeFunc::I_O      , abio );
1378   init_req( TypeFunc::Memory   , mem );
1379   init_req( TypeFunc::ReturnAdr, topnode );
1380   init_req( TypeFunc::FramePtr , topnode );
1381   init_req( AllocSize          , size);
1382   init_req( KlassNode          , klass_node);
1383   init_req( InitialTest        , initial_test);
1384   init_req( ALength            , topnode);
1385   C->add_macro_node(this);
1386 }
1387 
1388 void AllocateNode::compute_MemBar_redundancy(ciMethod* initializer)
1389 {
1390   assert(initializer != NULL &&
1391          initializer->is_initializer() &&
1392          !initializer->is_static(),
1393              "unexpected initializer method");
1394   BCEscapeAnalyzer* analyzer = initializer->get_bcea();
1395   if (analyzer == NULL) {
1396     return;
1397   }
1398 
1399   // Allocation node is first parameter in its initializer
1400   if (analyzer->is_arg_stack(0) || analyzer->is_arg_local(0)) {
1401     _is_allocation_MemBar_redundant = true;
1402   }
1403 }
1404 
1405 //=============================================================================
1406 Node* AllocateArrayNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1407   Node* res = SafePointNode::Ideal(phase, can_reshape);
1408   if (res != NULL) {
1409     return res;
1410   }
1411   // Don't bother trying to transform a dead node
1412   if (in(0) && in(0)->is_top())  return NULL;
1413 
1414   const Type* type = phase->type(Ideal_length());
1415   if (type->isa_int() && type->is_int()->_hi < 0) {
1416     if (can_reshape) {
1417       PhaseIterGVN *igvn = phase->is_IterGVN();
1418       // Unreachable fall through path (negative array length),
1419       // the allocation can only throw so disconnect it.
1420       Node* proj = proj_out(TypeFunc::Control);
1421       Node* catchproj = NULL;
1422       if (proj != NULL) {
1423         for (DUIterator_Fast imax, i = proj->fast_outs(imax); i < imax; i++) {
1424           Node *cn = proj->fast_out(i);
1425           if (cn->is_Catch()) {
1426             catchproj = cn->as_Multi()->proj_out(CatchProjNode::fall_through_index);
1427             break;
1428           }
1429         }
1430       }
1431       if (catchproj != NULL && catchproj->outcnt() > 0 &&
1432           (catchproj->outcnt() > 1 ||
1433            catchproj->unique_out()->Opcode() != Op_Halt)) {
1434         assert(catchproj->is_CatchProj(), "must be a CatchProjNode");
1435         Node* nproj = catchproj->clone();
1436         igvn->register_new_node_with_optimizer(nproj);
1437 
1438         Node *frame = new ParmNode( phase->C->start(), TypeFunc::FramePtr );
1439         frame = phase->transform(frame);
1440         // Halt & Catch Fire
1441         Node *halt = new HaltNode( nproj, frame );
1442         phase->C->root()->add_req(halt);
1443         phase->transform(halt);
1444 
1445         igvn->replace_node(catchproj, phase->C->top());
1446         return this;
1447       }
1448     } else {
1449       // Can't correct it during regular GVN so register for IGVN
1450       phase->C->record_for_igvn(this);
1451     }
1452   }
1453   return NULL;
1454 }
1455 
1456 // Retrieve the length from the AllocateArrayNode. Narrow the type with a
1457 // CastII, if appropriate.  If we are not allowed to create new nodes, and
1458 // a CastII is appropriate, return NULL.
1459 Node *AllocateArrayNode::make_ideal_length(const TypeOopPtr* oop_type, PhaseTransform *phase, bool allow_new_nodes) {
1460   Node *length = in(AllocateNode::ALength);
1461   assert(length != NULL, "length is not null");
1462 
1463   const TypeInt* length_type = phase->find_int_type(length);
1464   const TypeAryPtr* ary_type = oop_type->isa_aryptr();
1465 
1466   if (ary_type != NULL && length_type != NULL) {
1467     const TypeInt* narrow_length_type = ary_type->narrow_size_type(length_type);
1468     if (narrow_length_type != length_type) {
1469       // Assert one of:
1470       //   - the narrow_length is 0
1471       //   - the narrow_length is not wider than length
1472       assert(narrow_length_type == TypeInt::ZERO ||
1473              length_type->is_con() && narrow_length_type->is_con() &&
1474                 (narrow_length_type->_hi <= length_type->_lo) ||
1475              (narrow_length_type->_hi <= length_type->_hi &&
1476               narrow_length_type->_lo >= length_type->_lo),
1477              "narrow type must be narrower than length type");
1478 
1479       // Return NULL if new nodes are not allowed
1480       if (!allow_new_nodes) return NULL;
1481       // Create a cast which is control dependent on the initialization to
1482       // propagate the fact that the array length must be positive.
1483       length = new CastIINode(length, narrow_length_type);
1484       length->set_req(0, initialization()->proj_out(0));
1485     }
1486   }
1487 
1488   return length;
1489 }
1490 
1491 //=============================================================================
1492 uint LockNode::size_of() const { return sizeof(*this); }
1493 
1494 // Redundant lock elimination
1495 //
1496 // There are various patterns of locking where we release and
1497 // immediately reacquire a lock in a piece of code where no operations
1498 // occur in between that would be observable.  In those cases we can
1499 // skip releasing and reacquiring the lock without violating any
1500 // fairness requirements.  Doing this around a loop could cause a lock
1501 // to be held for a very long time so we concentrate on non-looping
1502 // control flow.  We also require that the operations are fully
1503 // redundant meaning that we don't introduce new lock operations on
1504 // some paths so to be able to eliminate it on others ala PRE.  This
1505 // would probably require some more extensive graph manipulation to
1506 // guarantee that the memory edges were all handled correctly.
1507 //
1508 // Assuming p is a simple predicate which can't trap in any way and s
1509 // is a synchronized method consider this code:
1510 //
1511 //   s();
1512 //   if (p)
1513 //     s();
1514 //   else
1515 //     s();
1516 //   s();
1517 //
1518 // 1. The unlocks of the first call to s can be eliminated if the
1519 // locks inside the then and else branches are eliminated.
1520 //
1521 // 2. The unlocks of the then and else branches can be eliminated if
1522 // the lock of the final call to s is eliminated.
1523 //
1524 // Either of these cases subsumes the simple case of sequential control flow
1525 //
1526 // Addtionally we can eliminate versions without the else case:
1527 //
1528 //   s();
1529 //   if (p)
1530 //     s();
1531 //   s();
1532 //
1533 // 3. In this case we eliminate the unlock of the first s, the lock
1534 // and unlock in the then case and the lock in the final s.
1535 //
1536 // Note also that in all these cases the then/else pieces don't have
1537 // to be trivial as long as they begin and end with synchronization
1538 // operations.
1539 //
1540 //   s();
1541 //   if (p)
1542 //     s();
1543 //     f();
1544 //     s();
1545 //   s();
1546 //
1547 // The code will work properly for this case, leaving in the unlock
1548 // before the call to f and the relock after it.
1549 //
1550 // A potentially interesting case which isn't handled here is when the
1551 // locking is partially redundant.
1552 //
1553 //   s();
1554 //   if (p)
1555 //     s();
1556 //
1557 // This could be eliminated putting unlocking on the else case and
1558 // eliminating the first unlock and the lock in the then side.
1559 // Alternatively the unlock could be moved out of the then side so it
1560 // was after the merge and the first unlock and second lock
1561 // eliminated.  This might require less manipulation of the memory
1562 // state to get correct.
1563 //
1564 // Additionally we might allow work between a unlock and lock before
1565 // giving up eliminating the locks.  The current code disallows any
1566 // conditional control flow between these operations.  A formulation
1567 // similar to partial redundancy elimination computing the
1568 // availability of unlocking and the anticipatability of locking at a
1569 // program point would allow detection of fully redundant locking with
1570 // some amount of work in between.  I'm not sure how often I really
1571 // think that would occur though.  Most of the cases I've seen
1572 // indicate it's likely non-trivial work would occur in between.
1573 // There may be other more complicated constructs where we could
1574 // eliminate locking but I haven't seen any others appear as hot or
1575 // interesting.
1576 //
1577 // Locking and unlocking have a canonical form in ideal that looks
1578 // roughly like this:
1579 //
1580 //              <obj>
1581 //                | \\------+
1582 //                |  \       \
1583 //                | BoxLock   \
1584 //                |  |   |     \
1585 //                |  |    \     \
1586 //                |  |   FastLock
1587 //                |  |   /
1588 //                |  |  /
1589 //                |  |  |
1590 //
1591 //               Lock
1592 //                |
1593 //            Proj #0
1594 //                |
1595 //            MembarAcquire
1596 //                |
1597 //            Proj #0
1598 //
1599 //            MembarRelease
1600 //                |
1601 //            Proj #0
1602 //                |
1603 //              Unlock
1604 //                |
1605 //            Proj #0
1606 //
1607 //
1608 // This code proceeds by processing Lock nodes during PhaseIterGVN
1609 // and searching back through its control for the proper code
1610 // patterns.  Once it finds a set of lock and unlock operations to
1611 // eliminate they are marked as eliminatable which causes the
1612 // expansion of the Lock and Unlock macro nodes to make the operation a NOP
1613 //
1614 //=============================================================================
1615 
1616 //
1617 // Utility function to skip over uninteresting control nodes.  Nodes skipped are:
1618 //   - copy regions.  (These may not have been optimized away yet.)
1619 //   - eliminated locking nodes
1620 //
1621 static Node *next_control(Node *ctrl) {
1622   if (ctrl == NULL)
1623     return NULL;
1624   while (1) {
1625     if (ctrl->is_Region()) {
1626       RegionNode *r = ctrl->as_Region();
1627       Node *n = r->is_copy();
1628       if (n == NULL)
1629         break;  // hit a region, return it
1630       else
1631         ctrl = n;
1632     } else if (ctrl->is_Proj()) {
1633       Node *in0 = ctrl->in(0);
1634       if (in0->is_AbstractLock() && in0->as_AbstractLock()->is_eliminated()) {
1635         ctrl = in0->in(0);
1636       } else {
1637         break;
1638       }
1639     } else {
1640       break; // found an interesting control
1641     }
1642   }
1643   return ctrl;
1644 }
1645 //
1646 // Given a control, see if it's the control projection of an Unlock which
1647 // operating on the same object as lock.
1648 //
1649 bool AbstractLockNode::find_matching_unlock(const Node* ctrl, LockNode* lock,
1650                                             GrowableArray<AbstractLockNode*> &lock_ops) {
1651   ProjNode *ctrl_proj = (ctrl->is_Proj()) ? ctrl->as_Proj() : NULL;
1652   if (ctrl_proj != NULL && ctrl_proj->_con == TypeFunc::Control) {
1653     Node *n = ctrl_proj->in(0);
1654     if (n != NULL && n->is_Unlock()) {
1655       UnlockNode *unlock = n->as_Unlock();
1656       if (lock->obj_node()->eqv_uncast(unlock->obj_node()) &&
1657           BoxLockNode::same_slot(lock->box_node(), unlock->box_node()) &&
1658           !unlock->is_eliminated()) {
1659         lock_ops.append(unlock);
1660         return true;
1661       }
1662     }
1663   }
1664   return false;
1665 }
1666 
1667 //
1668 // Find the lock matching an unlock.  Returns null if a safepoint
1669 // or complicated control is encountered first.
1670 LockNode *AbstractLockNode::find_matching_lock(UnlockNode* unlock) {
1671   LockNode *lock_result = NULL;
1672   // find the matching lock, or an intervening safepoint
1673   Node *ctrl = next_control(unlock->in(0));
1674   while (1) {
1675     assert(ctrl != NULL, "invalid control graph");
1676     assert(!ctrl->is_Start(), "missing lock for unlock");
1677     if (ctrl->is_top()) break;  // dead control path
1678     if (ctrl->is_Proj()) ctrl = ctrl->in(0);
1679     if (ctrl->is_SafePoint()) {
1680         break;  // found a safepoint (may be the lock we are searching for)
1681     } else if (ctrl->is_Region()) {
1682       // Check for a simple diamond pattern.  Punt on anything more complicated
1683       if (ctrl->req() == 3 && ctrl->in(1) != NULL && ctrl->in(2) != NULL) {
1684         Node *in1 = next_control(ctrl->in(1));
1685         Node *in2 = next_control(ctrl->in(2));
1686         if (((in1->is_IfTrue() && in2->is_IfFalse()) ||
1687              (in2->is_IfTrue() && in1->is_IfFalse())) && (in1->in(0) == in2->in(0))) {
1688           ctrl = next_control(in1->in(0)->in(0));
1689         } else {
1690           break;
1691         }
1692       } else {
1693         break;
1694       }
1695     } else {
1696       ctrl = next_control(ctrl->in(0));  // keep searching
1697     }
1698   }
1699   if (ctrl->is_Lock()) {
1700     LockNode *lock = ctrl->as_Lock();
1701     if (lock->obj_node()->eqv_uncast(unlock->obj_node()) &&
1702         BoxLockNode::same_slot(lock->box_node(), unlock->box_node())) {
1703       lock_result = lock;
1704     }
1705   }
1706   return lock_result;
1707 }
1708 
1709 // This code corresponds to case 3 above.
1710 
1711 bool AbstractLockNode::find_lock_and_unlock_through_if(Node* node, LockNode* lock,
1712                                                        GrowableArray<AbstractLockNode*> &lock_ops) {
1713   Node* if_node = node->in(0);
1714   bool  if_true = node->is_IfTrue();
1715 
1716   if (if_node->is_If() && if_node->outcnt() == 2 && (if_true || node->is_IfFalse())) {
1717     Node *lock_ctrl = next_control(if_node->in(0));
1718     if (find_matching_unlock(lock_ctrl, lock, lock_ops)) {
1719       Node* lock1_node = NULL;
1720       ProjNode* proj = if_node->as_If()->proj_out(!if_true);
1721       if (if_true) {
1722         if (proj->is_IfFalse() && proj->outcnt() == 1) {
1723           lock1_node = proj->unique_out();
1724         }
1725       } else {
1726         if (proj->is_IfTrue() && proj->outcnt() == 1) {
1727           lock1_node = proj->unique_out();
1728         }
1729       }
1730       if (lock1_node != NULL && lock1_node->is_Lock()) {
1731         LockNode *lock1 = lock1_node->as_Lock();
1732         if (lock->obj_node()->eqv_uncast(lock1->obj_node()) &&
1733             BoxLockNode::same_slot(lock->box_node(), lock1->box_node()) &&
1734             !lock1->is_eliminated()) {
1735           lock_ops.append(lock1);
1736           return true;
1737         }
1738       }
1739     }
1740   }
1741 
1742   lock_ops.trunc_to(0);
1743   return false;
1744 }
1745 
1746 bool AbstractLockNode::find_unlocks_for_region(const RegionNode* region, LockNode* lock,
1747                                GrowableArray<AbstractLockNode*> &lock_ops) {
1748   // check each control merging at this point for a matching unlock.
1749   // in(0) should be self edge so skip it.
1750   for (int i = 1; i < (int)region->req(); i++) {
1751     Node *in_node = next_control(region->in(i));
1752     if (in_node != NULL) {
1753       if (find_matching_unlock(in_node, lock, lock_ops)) {
1754         // found a match so keep on checking.
1755         continue;
1756       } else if (find_lock_and_unlock_through_if(in_node, lock, lock_ops)) {
1757         continue;
1758       }
1759 
1760       // If we fall through to here then it was some kind of node we
1761       // don't understand or there wasn't a matching unlock, so give
1762       // up trying to merge locks.
1763       lock_ops.trunc_to(0);
1764       return false;
1765     }
1766   }
1767   return true;
1768 
1769 }
1770 
1771 #ifndef PRODUCT
1772 //
1773 // Create a counter which counts the number of times this lock is acquired
1774 //
1775 void AbstractLockNode::create_lock_counter(JVMState* state) {
1776   _counter = OptoRuntime::new_named_counter(state, NamedCounter::LockCounter);
1777 }
1778 
1779 void AbstractLockNode::set_eliminated_lock_counter() {
1780   if (_counter) {
1781     // Update the counter to indicate that this lock was eliminated.
1782     // The counter update code will stay around even though the
1783     // optimizer will eliminate the lock operation itself.
1784     _counter->set_tag(NamedCounter::EliminatedLockCounter);
1785   }
1786 }
1787 
1788 const char* AbstractLockNode::_kind_names[] = {"Regular", "NonEscObj", "Coarsened", "Nested"};
1789 
1790 void AbstractLockNode::dump_spec(outputStream* st) const {
1791   st->print("%s ", _kind_names[_kind]);
1792   CallNode::dump_spec(st);
1793 }
1794 
1795 void AbstractLockNode::dump_compact_spec(outputStream* st) const {
1796   st->print("%s", _kind_names[_kind]);
1797 }
1798 
1799 // The related set of lock nodes includes the control boundary.
1800 void AbstractLockNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1801   if (compact) {
1802       this->collect_nodes(in_rel, 1, false, false);
1803     } else {
1804       this->collect_nodes_in_all_data(in_rel, true);
1805     }
1806     this->collect_nodes(out_rel, -2, false, false);
1807 }
1808 #endif
1809 
1810 //=============================================================================
1811 Node *LockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1812 
1813   // perform any generic optimizations first (returns 'this' or NULL)
1814   Node *result = SafePointNode::Ideal(phase, can_reshape);
1815   if (result != NULL)  return result;
1816   // Don't bother trying to transform a dead node
1817   if (in(0) && in(0)->is_top())  return NULL;
1818 
1819   // Now see if we can optimize away this lock.  We don't actually
1820   // remove the locking here, we simply set the _eliminate flag which
1821   // prevents macro expansion from expanding the lock.  Since we don't
1822   // modify the graph, the value returned from this function is the
1823   // one computed above.
1824   if (can_reshape && EliminateLocks && !is_non_esc_obj()) {
1825     //
1826     // If we are locking an unescaped object, the lock/unlock is unnecessary
1827     //
1828     ConnectionGraph *cgr = phase->C->congraph();
1829     if (cgr != NULL && cgr->not_global_escape(obj_node())) {
1830       assert(!is_eliminated() || is_coarsened(), "sanity");
1831       // The lock could be marked eliminated by lock coarsening
1832       // code during first IGVN before EA. Replace coarsened flag
1833       // to eliminate all associated locks/unlocks.
1834 #ifdef ASSERT
1835       this->log_lock_optimization(phase->C,"eliminate_lock_set_non_esc1");
1836 #endif
1837       this->set_non_esc_obj();
1838       return result;
1839     }
1840 
1841     //
1842     // Try lock coarsening
1843     //
1844     PhaseIterGVN* iter = phase->is_IterGVN();
1845     if (iter != NULL && !is_eliminated()) {
1846 
1847       GrowableArray<AbstractLockNode*>   lock_ops;
1848 
1849       Node *ctrl = next_control(in(0));
1850 
1851       // now search back for a matching Unlock
1852       if (find_matching_unlock(ctrl, this, lock_ops)) {
1853         // found an unlock directly preceding this lock.  This is the
1854         // case of single unlock directly control dependent on a
1855         // single lock which is the trivial version of case 1 or 2.
1856       } else if (ctrl->is_Region() ) {
1857         if (find_unlocks_for_region(ctrl->as_Region(), this, lock_ops)) {
1858         // found lock preceded by multiple unlocks along all paths
1859         // joining at this point which is case 3 in description above.
1860         }
1861       } else {
1862         // see if this lock comes from either half of an if and the
1863         // predecessors merges unlocks and the other half of the if
1864         // performs a lock.
1865         if (find_lock_and_unlock_through_if(ctrl, this, lock_ops)) {
1866           // found unlock splitting to an if with locks on both branches.
1867         }
1868       }
1869 
1870       if (lock_ops.length() > 0) {
1871         // add ourselves to the list of locks to be eliminated.
1872         lock_ops.append(this);
1873 
1874   #ifndef PRODUCT
1875         if (PrintEliminateLocks) {
1876           int locks = 0;
1877           int unlocks = 0;
1878           for (int i = 0; i < lock_ops.length(); i++) {
1879             AbstractLockNode* lock = lock_ops.at(i);
1880             if (lock->Opcode() == Op_Lock)
1881               locks++;
1882             else
1883               unlocks++;
1884             if (Verbose) {
1885               lock->dump(1);
1886             }
1887           }
1888           tty->print_cr("***Eliminated %d unlocks and %d locks", unlocks, locks);
1889         }
1890   #endif
1891 
1892         // for each of the identified locks, mark them
1893         // as eliminatable
1894         for (int i = 0; i < lock_ops.length(); i++) {
1895           AbstractLockNode* lock = lock_ops.at(i);
1896 
1897           // Mark it eliminated by coarsening and update any counters
1898 #ifdef ASSERT
1899           lock->log_lock_optimization(phase->C, "eliminate_lock_set_coarsened");
1900 #endif
1901           lock->set_coarsened();
1902         }
1903       } else if (ctrl->is_Region() &&
1904                  iter->_worklist.member(ctrl)) {
1905         // We weren't able to find any opportunities but the region this
1906         // lock is control dependent on hasn't been processed yet so put
1907         // this lock back on the worklist so we can check again once any
1908         // region simplification has occurred.
1909         iter->_worklist.push(this);
1910       }
1911     }
1912   }
1913 
1914   return result;
1915 }
1916 
1917 //=============================================================================
1918 bool LockNode::is_nested_lock_region() {
1919   return is_nested_lock_region(NULL);
1920 }
1921 
1922 // p is used for access to compilation log; no logging if NULL
1923 bool LockNode::is_nested_lock_region(Compile * c) {
1924   BoxLockNode* box = box_node()->as_BoxLock();
1925   int stk_slot = box->stack_slot();
1926   if (stk_slot <= 0) {
1927 #ifdef ASSERT
1928     this->log_lock_optimization(c, "eliminate_lock_INLR_1");
1929 #endif
1930     return false; // External lock or it is not Box (Phi node).
1931   }
1932 
1933   // Ignore complex cases: merged locks or multiple locks.
1934   Node* obj = obj_node();
1935   LockNode* unique_lock = NULL;
1936   if (!box->is_simple_lock_region(&unique_lock, obj)) {
1937 #ifdef ASSERT
1938     this->log_lock_optimization(c, "eliminate_lock_INLR_2a");
1939 #endif
1940     return false;
1941   }
1942   if (unique_lock != this) {
1943 #ifdef ASSERT
1944     this->log_lock_optimization(c, "eliminate_lock_INLR_2b");
1945 #endif
1946     return false;
1947   }
1948 
1949   // Look for external lock for the same object.
1950   SafePointNode* sfn = this->as_SafePoint();
1951   JVMState* youngest_jvms = sfn->jvms();
1952   int max_depth = youngest_jvms->depth();
1953   for (int depth = 1; depth <= max_depth; depth++) {
1954     JVMState* jvms = youngest_jvms->of_depth(depth);
1955     int num_mon  = jvms->nof_monitors();
1956     // Loop over monitors
1957     for (int idx = 0; idx < num_mon; idx++) {
1958       Node* obj_node = sfn->monitor_obj(jvms, idx);
1959       BoxLockNode* box_node = sfn->monitor_box(jvms, idx)->as_BoxLock();
1960       if ((box_node->stack_slot() < stk_slot) && obj_node->eqv_uncast(obj)) {
1961         return true;
1962       }
1963     }
1964   }
1965 #ifdef ASSERT
1966   this->log_lock_optimization(c, "eliminate_lock_INLR_3");
1967 #endif
1968   return false;
1969 }
1970 
1971 //=============================================================================
1972 uint UnlockNode::size_of() const { return sizeof(*this); }
1973 
1974 //=============================================================================
1975 Node *UnlockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1976 
1977   // perform any generic optimizations first (returns 'this' or NULL)
1978   Node *result = SafePointNode::Ideal(phase, can_reshape);
1979   if (result != NULL)  return result;
1980   // Don't bother trying to transform a dead node
1981   if (in(0) && in(0)->is_top())  return NULL;
1982 
1983   // Now see if we can optimize away this unlock.  We don't actually
1984   // remove the unlocking here, we simply set the _eliminate flag which
1985   // prevents macro expansion from expanding the unlock.  Since we don't
1986   // modify the graph, the value returned from this function is the
1987   // one computed above.
1988   // Escape state is defined after Parse phase.
1989   if (can_reshape && EliminateLocks && !is_non_esc_obj()) {
1990     //
1991     // If we are unlocking an unescaped object, the lock/unlock is unnecessary.
1992     //
1993     ConnectionGraph *cgr = phase->C->congraph();
1994     if (cgr != NULL && cgr->not_global_escape(obj_node())) {
1995       assert(!is_eliminated() || is_coarsened(), "sanity");
1996       // The lock could be marked eliminated by lock coarsening
1997       // code during first IGVN before EA. Replace coarsened flag
1998       // to eliminate all associated locks/unlocks.
1999 #ifdef ASSERT
2000       this->log_lock_optimization(phase->C, "eliminate_lock_set_non_esc2");
2001 #endif
2002       this->set_non_esc_obj();
2003     }
2004   }
2005   return result;
2006 }
2007 
2008 const char * AbstractLockNode::kind_as_string() const {
2009   return is_coarsened()   ? "coarsened" :
2010          is_nested()      ? "nested" :
2011          is_non_esc_obj() ? "non_escaping" :
2012          "?";
2013 }
2014 
2015 void AbstractLockNode::log_lock_optimization(Compile *C, const char * tag)  const {
2016   if (C == NULL) {
2017     return;
2018   }
2019   CompileLog* log = C->log();
2020   if (log != NULL) {
2021     log->begin_head("%s lock='%d' compile_id='%d' class_id='%s' kind='%s'",
2022           tag, is_Lock(), C->compile_id(),
2023           is_Unlock() ? "unlock" : is_Lock() ? "lock" : "?",
2024           kind_as_string());
2025     log->stamp();
2026     log->end_head();
2027     JVMState* p = is_Unlock() ? (as_Unlock()->dbg_jvms()) : jvms();
2028     while (p != NULL) {
2029       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
2030       p = p->caller();
2031     }
2032     log->tail(tag);
2033   }
2034 }
2035 
2036 bool CallNode::may_modify_arraycopy_helper(const TypeOopPtr* dest_t, const TypeOopPtr *t_oop, PhaseTransform *phase) {
2037   if (dest_t->is_known_instance() && t_oop->is_known_instance()) {
2038     return dest_t->instance_id() == t_oop->instance_id();
2039   }
2040 
2041   if (dest_t->isa_instptr() && !dest_t->klass()->equals(phase->C->env()->Object_klass())) {
2042     // clone
2043     if (t_oop->isa_aryptr()) {
2044       return false;
2045     }
2046     if (!t_oop->isa_instptr()) {
2047       return true;
2048     }
2049     if (dest_t->klass()->is_subtype_of(t_oop->klass()) || t_oop->klass()->is_subtype_of(dest_t->klass())) {
2050       return true;
2051     }
2052     // unrelated
2053     return false;
2054   }
2055 
2056   if (dest_t->isa_aryptr()) {
2057     // arraycopy or array clone
2058     if (t_oop->isa_instptr()) {
2059       return false;
2060     }
2061     if (!t_oop->isa_aryptr()) {
2062       return true;
2063     }
2064 
2065     const Type* elem = dest_t->is_aryptr()->elem();
2066     if (elem == Type::BOTTOM) {
2067       // An array but we don't know what elements are
2068       return true;
2069     }
2070 
2071     dest_t = dest_t->add_offset(Type::OffsetBot)->is_oopptr();
2072     uint dest_alias = phase->C->get_alias_index(dest_t);
2073     uint t_oop_alias = phase->C->get_alias_index(t_oop);
2074 
2075     return dest_alias == t_oop_alias;
2076   }
2077 
2078   return true;
2079 }
2080