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