jdk8-mips64-public/hotspot: src/share/vm/opto/callnode.cpp@1bd45abaa507 (annotated)

src/share/vm/opto/callnode.cpp@1bd45abaa507 (annotated)

src/share/vm/opto/callnode.cpp

Wed, 16 Nov 2011 09:13:57 -0800

author: kvn
date: Wed, 16 Nov 2011 09:13:57 -0800
changeset 3311: 1bd45abaa507
parent 2314: f95d63e2154a
child 3406: e9a5e0a812c8
permissions: -rw-r--r--

6890673: Eliminate allocations immediately after EA
Summary: Try to eliminate allocations and related locks immediately after escape analysis.
Reviewed-by: never

 /*
  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "ci/bcEscapeAnalyzer.hpp"
 #include "compiler/oopMap.hpp"
 #include "opto/callnode.hpp"
 #include "opto/escape.hpp"
 #include "opto/locknode.hpp"
 #include "opto/machnode.hpp"
 #include "opto/matcher.hpp"
 #include "opto/parse.hpp"
 #include "opto/regalloc.hpp"
 #include "opto/regmask.hpp"
 #include "opto/rootnode.hpp"
 #include "opto/runtime.hpp"
 // Portions of code courtesy of Clifford Click
 // Optimization - Graph Style
 //=============================================================================
 uint StartNode::size_of() const { return sizeof(*this); }
 uint StartNode::cmp( const Node &n ) const
 { return _domain == ((StartNode&)n)._domain; }
 const Type *StartNode::bottom_type() const { return _domain; }
 const Type *StartNode::Value(PhaseTransform *phase) const { return _domain; }
 #ifndef PRODUCT
 void StartNode::dump_spec(outputStream *st) const { st->print(" #"); _domain->dump_on(st);}
 #endif
 //------------------------------Ideal------------------------------------------
 Node *StartNode::Ideal(PhaseGVN *phase, bool can_reshape){
   return remove_dead_region(phase, can_reshape) ? this : NULL;
 }
 //------------------------------calling_convention-----------------------------
 void StartNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
   Matcher::calling_convention( sig_bt, parm_regs, argcnt, false );
 }
 //------------------------------Registers--------------------------------------
 const RegMask &StartNode::in_RegMask(uint) const {
   return RegMask::Empty;
 }
 //------------------------------match------------------------------------------
 // Construct projections for incoming parameters, and their RegMask info
 Node *StartNode::match( const ProjNode *proj, const Matcher *match ) {
   switch (proj->_con) {
   case TypeFunc::Control:
   case TypeFunc::I_O:
   case TypeFunc::Memory:
     return new (match->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
   case TypeFunc::FramePtr:
     return new (match->C, 1) MachProjNode(this,proj->_con,Matcher::c_frame_ptr_mask, Op_RegP);
   case TypeFunc::ReturnAdr:
     return new (match->C, 1) MachProjNode(this,proj->_con,match->_return_addr_mask,Op_RegP);
   case TypeFunc::Parms:
   default: {
       uint parm_num = proj->_con - TypeFunc::Parms;
       const Type *t = _domain->field_at(proj->_con);
       if (t->base() == Type::Half)  // 2nd half of Longs and Doubles
         return new (match->C, 1) ConNode(Type::TOP);
       uint ideal_reg = Matcher::base2reg[t->base()];
       RegMask &rm = match->_calling_convention_mask[parm_num];
       return new (match->C, 1) MachProjNode(this,proj->_con,rm,ideal_reg);
     }
   }
   return NULL;
 }
 //------------------------------StartOSRNode----------------------------------
 // The method start node for an on stack replacement adapter
 //------------------------------osr_domain-----------------------------
 const TypeTuple *StartOSRNode::osr_domain() {
   const Type **fields = TypeTuple::fields(2);
   fields[TypeFunc::Parms+0] = TypeRawPtr::BOTTOM;  // address of osr buffer
   return TypeTuple::make(TypeFunc::Parms+1, fields);
 }
 //=============================================================================
 const char * const ParmNode::names[TypeFunc::Parms+1] = {
   "Control", "I_O", "Memory", "FramePtr", "ReturnAdr", "Parms"
 };
 #ifndef PRODUCT
 void ParmNode::dump_spec(outputStream *st) const {
   if( _con < TypeFunc::Parms ) {
     st->print(names[_con]);
   } else {
     st->print("Parm%d: ",_con-TypeFunc::Parms);
     // Verbose and WizardMode dump bottom_type for all nodes
     if( !Verbose && !WizardMode )   bottom_type()->dump_on(st);
   }
 }
 #endif
 uint ParmNode::ideal_reg() const {
   switch( _con ) {
   case TypeFunc::Control  : // fall through
   case TypeFunc::I_O      : // fall through
   case TypeFunc::Memory   : return 0;
   case TypeFunc::FramePtr : // fall through
   case TypeFunc::ReturnAdr: return Op_RegP;
   default                 : assert( _con > TypeFunc::Parms, "" );
     // fall through
   case TypeFunc::Parms    : {
     // Type of argument being passed
     const Type *t = in(0)->as_Start()->_domain->field_at(_con);
     return Matcher::base2reg[t->base()];
   }
   }
   ShouldNotReachHere();
   return 0;
 }
 //=============================================================================
 ReturnNode::ReturnNode(uint edges, Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *retadr ) : Node(edges) {
   init_req(TypeFunc::Control,cntrl);
   init_req(TypeFunc::I_O,i_o);
   init_req(TypeFunc::Memory,memory);
   init_req(TypeFunc::FramePtr,frameptr);
   init_req(TypeFunc::ReturnAdr,retadr);
 }
 Node *ReturnNode::Ideal(PhaseGVN *phase, bool can_reshape){
   return remove_dead_region(phase, can_reshape) ? this : NULL;
 }
 const Type *ReturnNode::Value( PhaseTransform *phase ) const {
   return ( phase->type(in(TypeFunc::Control)) == Type::TOP)
     ? Type::TOP
     : Type::BOTTOM;
 }
 // Do we Match on this edge index or not?  No edges on return nodes
 uint ReturnNode::match_edge(uint idx) const {
   return 0;
 }
 #ifndef PRODUCT
 void ReturnNode::dump_req() const {
   // Dump the required inputs, enclosed in '(' and ')'
   uint i;                       // Exit value of loop
   for( i=0; i<req(); i++ ) {    // For all required inputs
     if( i == TypeFunc::Parms ) tty->print("returns");
     if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
     else tty->print("_ ");
   }
 }
 #endif
 //=============================================================================
 RethrowNode::RethrowNode(
   Node* cntrl,
   Node* i_o,
   Node* memory,
   Node* frameptr,
   Node* ret_adr,
   Node* exception
 ) : Node(TypeFunc::Parms + 1) {
   init_req(TypeFunc::Control  , cntrl    );
   init_req(TypeFunc::I_O      , i_o      );
   init_req(TypeFunc::Memory   , memory   );
   init_req(TypeFunc::FramePtr , frameptr );
   init_req(TypeFunc::ReturnAdr, ret_adr);
   init_req(TypeFunc::Parms    , exception);
 }
 Node *RethrowNode::Ideal(PhaseGVN *phase, bool can_reshape){
   return remove_dead_region(phase, can_reshape) ? this : NULL;
 }
 const Type *RethrowNode::Value( PhaseTransform *phase ) const {
   return (phase->type(in(TypeFunc::Control)) == Type::TOP)
     ? Type::TOP
     : Type::BOTTOM;
 }
 uint RethrowNode::match_edge(uint idx) const {
   return 0;
 }
 #ifndef PRODUCT
 void RethrowNode::dump_req() const {
   // Dump the required inputs, enclosed in '(' and ')'
   uint i;                       // Exit value of loop
   for( i=0; i<req(); i++ ) {    // For all required inputs
     if( i == TypeFunc::Parms ) tty->print("exception");
     if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
     else tty->print("_ ");
   }
 }
 #endif
 //=============================================================================
 // Do we Match on this edge index or not?  Match only target address & method
 uint TailCallNode::match_edge(uint idx) const {
   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 }
 //=============================================================================
 // Do we Match on this edge index or not?  Match only target address & oop
 uint TailJumpNode::match_edge(uint idx) const {
   return TypeFunc::Parms <= idx  &&  idx <= TypeFunc::Parms+1;
 }
 //=============================================================================
 JVMState::JVMState(ciMethod* method, JVMState* caller) {
   assert(method != NULL, "must be valid call site");
   _method = method;
   _reexecute = Reexecute_Undefined;
   debug_only(_bci = -99);  // random garbage value
   debug_only(_map = (SafePointNode*)-1);
   _caller = caller;
   _depth  = 1 + (caller == NULL ? 0 : caller->depth());
   _locoff = TypeFunc::Parms;
   _stkoff = _locoff + _method->max_locals();
   _monoff = _stkoff + _method->max_stack();
   _scloff = _monoff;
   _endoff = _monoff;
   _sp = 0;
 }
 JVMState::JVMState(int stack_size) {
   _method = NULL;
   _bci = InvocationEntryBci;
   _reexecute = Reexecute_Undefined;
   debug_only(_map = (SafePointNode*)-1);
   _caller = NULL;
   _depth  = 1;
   _locoff = TypeFunc::Parms;
   _stkoff = _locoff;
   _monoff = _stkoff + stack_size;
   _scloff = _monoff;
   _endoff = _monoff;
   _sp = 0;
 }
 //--------------------------------of_depth-------------------------------------
 JVMState* JVMState::of_depth(int d) const {
   const JVMState* jvmp = this;
   assert(0 < d && (uint)d <= depth(), "oob");
   for (int skip = depth() - d; skip > 0; skip--) {
     jvmp = jvmp->caller();
   }
   assert(jvmp->depth() == (uint)d, "found the right one");
   return (JVMState*)jvmp;
 }
 //-----------------------------same_calls_as-----------------------------------
 bool JVMState::same_calls_as(const JVMState* that) const {
   if (this == that)                    return true;
   if (this->depth() != that->depth())  return false;
   const JVMState* p = this;
   const JVMState* q = that;
   for (;;) {
     if (p->_method != q->_method)    return false;
     if (p->_method == NULL)          return true;   // bci is irrelevant
     if (p->_bci    != q->_bci)       return false;
     if (p->_reexecute != q->_reexecute)  return false;
     p = p->caller();
     q = q->caller();
     if (p == q)                      return true;
     assert(p != NULL && q != NULL, "depth check ensures we don't run off end");
   }
 }
 //------------------------------debug_start------------------------------------
 uint JVMState::debug_start()  const {
   debug_only(JVMState* jvmroot = of_depth(1));
   assert(jvmroot->locoff() <= this->locoff(), "youngest JVMState must be last");
   return of_depth(1)->locoff();
 }
 //-------------------------------debug_end-------------------------------------
 uint JVMState::debug_end() const {
   debug_only(JVMState* jvmroot = of_depth(1));
   assert(jvmroot->endoff() <= this->endoff(), "youngest JVMState must be last");
   return endoff();
 }
 //------------------------------debug_depth------------------------------------
 uint JVMState::debug_depth() const {
   uint total = 0;
   for (const JVMState* jvmp = this; jvmp != NULL; jvmp = jvmp->caller()) {
     total += jvmp->debug_size();
   }
   return total;
 }
 #ifndef PRODUCT
 //------------------------------format_helper----------------------------------
 // Given an allocation (a Chaitin object) and a Node decide if the Node carries
 // any defined value or not.  If it does, print out the register or constant.
 static void format_helper( PhaseRegAlloc *regalloc, outputStream* st, Node *n, const char *msg, uint i, GrowableArray<SafePointScalarObjectNode*> *scobjs ) {
   if (n == NULL) { st->print(" NULL"); return; }
   if (n->is_SafePointScalarObject()) {
     // Scalar replacement.
     SafePointScalarObjectNode* spobj = n->as_SafePointScalarObject();
     scobjs->append_if_missing(spobj);
     int sco_n = scobjs->find(spobj);
     assert(sco_n >= 0, "");
     st->print(" %s%d]=#ScObj" INT32_FORMAT, msg, i, sco_n);
     return;
   }
   if( OptoReg::is_valid(regalloc->get_reg_first(n))) { // Check for undefined
     char buf[50];
     regalloc->dump_register(n,buf);
     st->print(" %s%d]=%s",msg,i,buf);
   } else {                      // No register, but might be constant
     const Type *t = n->bottom_type();
     switch (t->base()) {
     case Type::Int:
       st->print(" %s%d]=#"INT32_FORMAT,msg,i,t->is_int()->get_con());
       break;
     case Type::AnyPtr:
       assert( t == TypePtr::NULL_PTR, "" );
       st->print(" %s%d]=#NULL",msg,i);
       break;
     case Type::AryPtr:
     case Type::KlassPtr:
     case Type::InstPtr:
       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,t->isa_oopptr()->const_oop());
       break;
     case Type::NarrowOop:
       st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,t->make_ptr()->isa_oopptr()->const_oop());
       break;
     case Type::RawPtr:
       st->print(" %s%d]=#Raw" INTPTR_FORMAT,msg,i,t->is_rawptr());
       break;
     case Type::DoubleCon:
       st->print(" %s%d]=#%fD",msg,i,t->is_double_constant()->_d);
       break;
     case Type::FloatCon:
       st->print(" %s%d]=#%fF",msg,i,t->is_float_constant()->_f);
       break;
     case Type::Long:
       st->print(" %s%d]=#"INT64_FORMAT,msg,i,t->is_long()->get_con());
       break;
     case Type::Half:
     case Type::Top:
       st->print(" %s%d]=_",msg,i);
       break;
     default: ShouldNotReachHere();
     }
   }
 }
 //------------------------------format-----------------------------------------
 void JVMState::format(PhaseRegAlloc *regalloc, const Node *n, outputStream* st) const {
   st->print("        #");
   if( _method ) {
     _method->print_short_name(st);
     st->print(" @ bci:%d ",_bci);
   } else {
     st->print_cr(" runtime stub ");
     return;
   }
   if (n->is_MachSafePoint()) {
     GrowableArray<SafePointScalarObjectNode*> scobjs;
     MachSafePointNode *mcall = n->as_MachSafePoint();
     uint i;
     // Print locals
     for( i = 0; i < (uint)loc_size(); i++ )
       format_helper( regalloc, st, mcall->local(this, i), "L[", i, &scobjs );
     // Print stack
     for (i = 0; i < (uint)stk_size(); i++) {
       if ((uint)(_stkoff + i) >= mcall->len())
         st->print(" oob ");
       else
        format_helper( regalloc, st, mcall->stack(this, i), "STK[", i, &scobjs );
     }
     for (i = 0; (int)i < nof_monitors(); i++) {
       Node *box = mcall->monitor_box(this, i);
       Node *obj = mcall->monitor_obj(this, i);
       if ( OptoReg::is_valid(regalloc->get_reg_first(box)) ) {
         while( !box->is_BoxLock() )  box = box->in(1);
         format_helper( regalloc, st, box, "MON-BOX[", i, &scobjs );
       } else {
         OptoReg::Name box_reg = BoxLockNode::stack_slot(box);
         st->print(" MON-BOX%d=%s+%d",
                    i,
                    OptoReg::regname(OptoReg::c_frame_pointer),
                    regalloc->reg2offset(box_reg));
       }
       const char* obj_msg = "MON-OBJ[";
       if (EliminateLocks) {
         while( !box->is_BoxLock() )  box = box->in(1);
         if (box->as_BoxLock()->is_eliminated())
           obj_msg = "MON-OBJ(LOCK ELIMINATED)[";
       }
       format_helper( regalloc, st, obj, obj_msg, i, &scobjs );
     }
     for (i = 0; i < (uint)scobjs.length(); i++) {
       // Scalar replaced objects.
       st->print_cr("");
       st->print("        # ScObj" INT32_FORMAT " ", i);
       SafePointScalarObjectNode* spobj = scobjs.at(i);
       ciKlass* cik = spobj->bottom_type()->is_oopptr()->klass();
       assert(cik->is_instance_klass() ||
              cik->is_array_klass(), "Not supported allocation.");
       ciInstanceKlass *iklass = NULL;
       if (cik->is_instance_klass()) {
         cik->print_name_on(st);
         iklass = cik->as_instance_klass();
       } else if (cik->is_type_array_klass()) {
         cik->as_array_klass()->base_element_type()->print_name_on(st);
         st->print("[%d]", spobj->n_fields());
       } else if (cik->is_obj_array_klass()) {
         ciKlass* cie = cik->as_obj_array_klass()->base_element_klass();
         if (cie->is_instance_klass()) {
           cie->print_name_on(st);
         } else if (cie->is_type_array_klass()) {
           cie->as_array_klass()->base_element_type()->print_name_on(st);
         } else {
           ShouldNotReachHere();
         }
         st->print("[%d]", spobj->n_fields());
         int ndim = cik->as_array_klass()->dimension() - 1;
         while (ndim-- > 0) {
           st->print("[]");
         }
       }
       st->print("={");
       uint nf = spobj->n_fields();
       if (nf > 0) {
         uint first_ind = spobj->first_index();
         Node* fld_node = mcall->in(first_ind);
         ciField* cifield;
         if (iklass != NULL) {
           st->print(" [");
           cifield = iklass->nonstatic_field_at(0);
           cifield->print_name_on(st);
           format_helper( regalloc, st, fld_node, ":", 0, &scobjs );
         } else {
           format_helper( regalloc, st, fld_node, "[", 0, &scobjs );
         }
         for (uint j = 1; j < nf; j++) {
           fld_node = mcall->in(first_ind+j);
           if (iklass != NULL) {
             st->print(", [");
             cifield = iklass->nonstatic_field_at(j);
             cifield->print_name_on(st);
             format_helper( regalloc, st, fld_node, ":", j, &scobjs );
           } else {
             format_helper( regalloc, st, fld_node, ", [", j, &scobjs );
           }
         }
       }
       st->print(" }");
     }
   }
   st->print_cr("");
   if (caller() != NULL)  caller()->format(regalloc, n, st);
 }
 void JVMState::dump_spec(outputStream *st) const {
   if (_method != NULL) {
     bool printed = false;
     if (!Verbose) {
       // The JVMS dumps make really, really long lines.
       // Take out the most boring parts, which are the package prefixes.
       char buf[500];
       stringStream namest(buf, sizeof(buf));
       _method->print_short_name(&namest);
       if (namest.count() < sizeof(buf)) {
         const char* name = namest.base();
         if (name[0] == ' ')  ++name;
         const char* endcn = strchr(name, ':');  // end of class name
         if (endcn == NULL)  endcn = strchr(name, '(');
         if (endcn == NULL)  endcn = name + strlen(name);
         while (endcn > name && endcn[-1] != '.' && endcn[-1] != '/')
           --endcn;
         st->print(" %s", endcn);
         printed = true;
       }
     }
     if (!printed)
       _method->print_short_name(st);
     st->print(" @ bci:%d",_bci);
     if(_reexecute == Reexecute_True)
       st->print(" reexecute");
   } else {
     st->print(" runtime stub");
   }
   if (caller() != NULL)  caller()->dump_spec(st);
 }
 void JVMState::dump_on(outputStream* st) const {
   if (_map && !((uintptr_t)_map & 1)) {
     if (_map->len() > _map->req()) {  // _map->has_exceptions()
       Node* ex = _map->in(_map->req());  // _map->next_exception()
       // skip the first one; it's already being printed
       while (ex != NULL && ex->len() > ex->req()) {
         ex = ex->in(ex->req());  // ex->next_exception()
         ex->dump(1);
       }
     }
     _map->dump(2);
   }
   st->print("JVMS depth=%d loc=%d stk=%d mon=%d scalar=%d end=%d mondepth=%d sp=%d bci=%d reexecute=%s method=",
              depth(), locoff(), stkoff(), monoff(), scloff(), endoff(), monitor_depth(), sp(), bci(), should_reexecute()?"true":"false");
   if (_method == NULL) {
     st->print_cr("(none)");
   } else {
     _method->print_name(st);
     st->cr();
     if (bci() >= 0 && bci() < _method->code_size()) {
       st->print("    bc: ");
       _method->print_codes_on(bci(), bci()+1, st);
     }
   }
   if (caller() != NULL) {
     caller()->dump_on(st);
   }
 }
 // Extra way to dump a jvms from the debugger,
 // to avoid a bug with C++ member function calls.
 void dump_jvms(JVMState* jvms) {
   jvms->dump();
 }
 #endif
 //--------------------------clone_shallow--------------------------------------
 JVMState* JVMState::clone_shallow(Compile* C) const {
   JVMState* n = has_method() ? new (C) JVMState(_method, _caller) : new (C) JVMState(0);
   n->set_bci(_bci);
   n->_reexecute = _reexecute;
   n->set_locoff(_locoff);
   n->set_stkoff(_stkoff);
   n->set_monoff(_monoff);
   n->set_scloff(_scloff);
   n->set_endoff(_endoff);
   n->set_sp(_sp);
   n->set_map(_map);
   return n;
 }
 //---------------------------clone_deep----------------------------------------
 JVMState* JVMState::clone_deep(Compile* C) const {
   JVMState* n = clone_shallow(C);
   for (JVMState* p = n; p->_caller != NULL; p = p->_caller) {
     p->_caller = p->_caller->clone_shallow(C);
   }
   assert(n->depth() == depth(), "sanity");
   assert(n->debug_depth() == debug_depth(), "sanity");
   return n;
 }
 //=============================================================================
 uint CallNode::cmp( const Node &n ) const
 { return _tf == ((CallNode&)n)._tf && _jvms == ((CallNode&)n)._jvms; }
 #ifndef PRODUCT
 void CallNode::dump_req() const {
   // Dump the required inputs, enclosed in '(' and ')'
   uint i;                       // Exit value of loop
   for( i=0; i<req(); i++ ) {    // For all required inputs
     if( i == TypeFunc::Parms ) tty->print("(");
     if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
     else tty->print("_ ");
   }
   tty->print(")");
 }
 void CallNode::dump_spec(outputStream *st) const {
   st->print(" ");
   tf()->dump_on(st);
   if (_cnt != COUNT_UNKNOWN)  st->print(" C=%f",_cnt);
   if (jvms() != NULL)  jvms()->dump_spec(st);
 }
 #endif
 const Type *CallNode::bottom_type() const { return tf()->range(); }
 const Type *CallNode::Value(PhaseTransform *phase) const {
   if (phase->type(in(0)) == Type::TOP)  return Type::TOP;
   return tf()->range();
 }
 //------------------------------calling_convention-----------------------------
 void CallNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
   // Use the standard compiler calling convention
   Matcher::calling_convention( sig_bt, parm_regs, argcnt, true );
 }
 //------------------------------match------------------------------------------
 // Construct projections for control, I/O, memory-fields, ..., and
 // return result(s) along with their RegMask info
 Node *CallNode::match( const ProjNode *proj, const Matcher *match ) {
   switch (proj->_con) {
   case TypeFunc::Control:
   case TypeFunc::I_O:
   case TypeFunc::Memory:
     return new (match->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
   case TypeFunc::Parms+1:       // For LONG & DOUBLE returns
     assert(tf()->_range->field_at(TypeFunc::Parms+1) == Type::HALF, "");
     // 2nd half of doubles and longs
     return new (match->C, 1) MachProjNode(this,proj->_con, RegMask::Empty, (uint)OptoReg::Bad);
   case TypeFunc::Parms: {       // Normal returns
     uint ideal_reg = Matcher::base2reg[tf()->range()->field_at(TypeFunc::Parms)->base()];
     OptoRegPair regs = is_CallRuntime()
       ? match->c_return_value(ideal_reg,true)  // Calls into C runtime
       : match->  return_value(ideal_reg,true); // Calls into compiled Java code
     RegMask rm = RegMask(regs.first());
     if( OptoReg::is_valid(regs.second()) )
       rm.Insert( regs.second() );
     return new (match->C, 1) MachProjNode(this,proj->_con,rm,ideal_reg);
   }
   case TypeFunc::ReturnAdr:
   case TypeFunc::FramePtr:
   default:
     ShouldNotReachHere();
   }
   return NULL;
 }
 // Do we Match on this edge index or not?  Match no edges
 uint CallNode::match_edge(uint idx) const {
   return 0;
 }
 //
 // Determine whether the call could modify the field of the specified
 // instance at the specified offset.
 //
 bool CallNode::may_modify(const TypePtr *addr_t, PhaseTransform *phase) {
   const TypeOopPtr *adrInst_t  = addr_t->isa_oopptr();
   // If not an OopPtr or not an instance type, assume the worst.
   // Note: currently this method is called only for instance types.
   if (adrInst_t == NULL || !adrInst_t->is_known_instance()) {
     return true;
   }
   // The instance_id is set only for scalar-replaceable allocations which
   // are not passed as arguments according to Escape Analysis.
   return false;
 }
 // Does this call have a direct reference to n other than debug information?
 bool CallNode::has_non_debug_use(Node *n) {
   const TypeTuple * d = tf()->domain();
   for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
     Node *arg = in(i);
     if (arg == n) {
       return true;
     }
   }
   return false;
 }
 // Returns the unique CheckCastPP of a call
 // or 'this' if there are several CheckCastPP
 // or returns NULL if there is no one.
 Node *CallNode::result_cast() {
   Node *cast = NULL;
   Node *p = proj_out(TypeFunc::Parms);
   if (p == NULL)
     return NULL;
   for (DUIterator_Fast imax, i = p->fast_outs(imax); i < imax; i++) {
     Node *use = p->fast_out(i);
     if (use->is_CheckCastPP()) {
       if (cast != NULL) {
         return this;  // more than 1 CheckCastPP
       }
       cast = use;
     }
   }
   return cast;
 }
 void CallNode::extract_projections(CallProjections* projs, bool separate_io_proj) {
   projs->fallthrough_proj      = NULL;
   projs->fallthrough_catchproj = NULL;
   projs->fallthrough_ioproj    = NULL;
   projs->catchall_ioproj       = NULL;
   projs->catchall_catchproj    = NULL;
   projs->fallthrough_memproj   = NULL;
   projs->catchall_memproj      = NULL;
   projs->resproj               = NULL;
   projs->exobj                 = NULL;
   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
     ProjNode *pn = fast_out(i)->as_Proj();
     if (pn->outcnt() == 0) continue;
     switch (pn->_con) {
     case TypeFunc::Control:
       {
         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
         projs->fallthrough_proj = pn;
         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
         const Node *cn = pn->fast_out(j);
         if (cn->is_Catch()) {
           ProjNode *cpn = NULL;
           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
             cpn = cn->fast_out(k)->as_Proj();
             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
             if (cpn->_con == CatchProjNode::fall_through_index)
               projs->fallthrough_catchproj = cpn;
             else {
               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
               projs->catchall_catchproj = cpn;
             }
           }
         }
         break;
       }
     case TypeFunc::I_O:
       if (pn->_is_io_use)
         projs->catchall_ioproj = pn;
       else
         projs->fallthrough_ioproj = pn;
       for (DUIterator j = pn->outs(); pn->has_out(j); j++) {
         Node* e = pn->out(j);
         if (e->Opcode() == Op_CreateEx && e->in(0)->is_CatchProj()) {
           assert(projs->exobj == NULL, "only one");
           projs->exobj = e;
         }
       }
       break;
     case TypeFunc::Memory:
       if (pn->_is_io_use)
         projs->catchall_memproj = pn;
       else
         projs->fallthrough_memproj = pn;
       break;
     case TypeFunc::Parms:
       projs->resproj = pn;
       break;
     default:
       assert(false, "unexpected projection from allocation node.");
     }
   }
   // The resproj may not exist because the result couuld be ignored
   // and the exception object may not exist if an exception handler
   // swallows the exception but all the other must exist and be found.
   assert(projs->fallthrough_proj      != NULL, "must be found");
   assert(projs->fallthrough_catchproj != NULL, "must be found");
   assert(projs->fallthrough_memproj   != NULL, "must be found");
   assert(projs->fallthrough_ioproj    != NULL, "must be found");
   assert(projs->catchall_catchproj    != NULL, "must be found");
   if (separate_io_proj) {
     assert(projs->catchall_memproj      != NULL, "must be found");
     assert(projs->catchall_ioproj       != NULL, "must be found");
   }
 }
 //=============================================================================
 uint CallJavaNode::size_of() const { return sizeof(*this); }
 uint CallJavaNode::cmp( const Node &n ) const {
   CallJavaNode &call = (CallJavaNode&)n;
   return CallNode::cmp(call) && _method == call._method;
 }
 #ifndef PRODUCT
 void CallJavaNode::dump_spec(outputStream *st) const {
   if( _method ) _method->print_short_name(st);
   CallNode::dump_spec(st);
 }
 #endif
 //=============================================================================
 uint CallStaticJavaNode::size_of() const { return sizeof(*this); }
 uint CallStaticJavaNode::cmp( const Node &n ) const {
   CallStaticJavaNode &call = (CallStaticJavaNode&)n;
   return CallJavaNode::cmp(call);
 }
 //----------------------------uncommon_trap_request----------------------------
 // If this is an uncommon trap, return the request code, else zero.
 int CallStaticJavaNode::uncommon_trap_request() const {
   if (_name != NULL && !strcmp(_name, "uncommon_trap")) {
     return extract_uncommon_trap_request(this);
   }
   return 0;
 }
 int CallStaticJavaNode::extract_uncommon_trap_request(const Node* call) {
 #ifndef PRODUCT
   if (!(call->req() > TypeFunc::Parms &&
         call->in(TypeFunc::Parms) != NULL &&
         call->in(TypeFunc::Parms)->is_Con())) {
     assert(_in_dump_cnt != 0, "OK if dumping");
     tty->print("[bad uncommon trap]");
     return 0;
   }
 #endif
   return call->in(TypeFunc::Parms)->bottom_type()->is_int()->get_con();
 }
 #ifndef PRODUCT
 void CallStaticJavaNode::dump_spec(outputStream *st) const {
   st->print("# Static ");
   if (_name != NULL) {
     st->print("%s", _name);
     int trap_req = uncommon_trap_request();
     if (trap_req != 0) {
       char buf[100];
       st->print("(%s)",
                  Deoptimization::format_trap_request(buf, sizeof(buf),
                                                      trap_req));
     }
     st->print(" ");
   }
   CallJavaNode::dump_spec(st);
 }
 #endif
 //=============================================================================
 uint CallDynamicJavaNode::size_of() const { return sizeof(*this); }
 uint CallDynamicJavaNode::cmp( const Node &n ) const {
   CallDynamicJavaNode &call = (CallDynamicJavaNode&)n;
   return CallJavaNode::cmp(call);
 }
 #ifndef PRODUCT
 void CallDynamicJavaNode::dump_spec(outputStream *st) const {
   st->print("# Dynamic ");
   CallJavaNode::dump_spec(st);
 }
 #endif
 //=============================================================================
 uint CallRuntimeNode::size_of() const { return sizeof(*this); }
 uint CallRuntimeNode::cmp( const Node &n ) const {
   CallRuntimeNode &call = (CallRuntimeNode&)n;
   return CallNode::cmp(call) && !strcmp(_name,call._name);
 }
 #ifndef PRODUCT
 void CallRuntimeNode::dump_spec(outputStream *st) const {
   st->print("# ");
   st->print(_name);
   CallNode::dump_spec(st);
 }
 #endif
 //------------------------------calling_convention-----------------------------
 void CallRuntimeNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
   Matcher::c_calling_convention( sig_bt, parm_regs, argcnt );
 }
 //=============================================================================
 //------------------------------calling_convention-----------------------------
 //=============================================================================
 #ifndef PRODUCT
 void CallLeafNode::dump_spec(outputStream *st) const {
   st->print("# ");
   st->print(_name);
   CallNode::dump_spec(st);
 }
 #endif
 //=============================================================================
 void SafePointNode::set_local(JVMState* jvms, uint idx, Node *c) {
   assert(verify_jvms(jvms), "jvms must match");
   int loc = jvms->locoff() + idx;
   if (in(loc)->is_top() && idx > 0 && !c->is_top() ) {
     // If current local idx is top then local idx - 1 could
     // be a long/double that needs to be killed since top could
     // represent the 2nd half ofthe long/double.
     uint ideal = in(loc -1)->ideal_reg();
     if (ideal == Op_RegD || ideal == Op_RegL) {
       // set other (low index) half to top
       set_req(loc - 1, in(loc));
     }
   }
   set_req(loc, c);
 }
 uint SafePointNode::size_of() const { return sizeof(*this); }
 uint SafePointNode::cmp( const Node &n ) const {
   return (&n == this);          // Always fail except on self
 }
 //-------------------------set_next_exception----------------------------------
 void SafePointNode::set_next_exception(SafePointNode* n) {
   assert(n == NULL || n->Opcode() == Op_SafePoint, "correct value for next_exception");
   if (len() == req()) {
     if (n != NULL)  add_prec(n);
   } else {
     set_prec(req(), n);
   }
 }
 //----------------------------next_exception-----------------------------------
 SafePointNode* SafePointNode::next_exception() const {
   if (len() == req()) {
     return NULL;
   } else {
     Node* n = in(req());
     assert(n == NULL || n->Opcode() == Op_SafePoint, "no other uses of prec edges");
     return (SafePointNode*) n;
   }
 }
 //------------------------------Ideal------------------------------------------
 // Skip over any collapsed Regions
 Node *SafePointNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   return remove_dead_region(phase, can_reshape) ? this : NULL;
 }
 //------------------------------Identity---------------------------------------
 // Remove obviously duplicate safepoints
 Node *SafePointNode::Identity( PhaseTransform *phase ) {
   // If you have back to back safepoints, remove one
   if( in(TypeFunc::Control)->is_SafePoint() )
     return in(TypeFunc::Control);
   if( in(0)->is_Proj() ) {
     Node *n0 = in(0)->in(0);
     // Check if he is a call projection (except Leaf Call)
     if( n0->is_Catch() ) {
       n0 = n0->in(0)->in(0);
       assert( n0->is_Call(), "expect a call here" );
     }
     if( n0->is_Call() && n0->as_Call()->guaranteed_safepoint() ) {
       // Useless Safepoint, so remove it
       return in(TypeFunc::Control);
     }
   }
   return this;
 }
 //------------------------------Value------------------------------------------
 const Type *SafePointNode::Value( PhaseTransform *phase ) const {
   if( phase->type(in(0)) == Type::TOP ) return Type::TOP;
   if( phase->eqv( in(0), this ) ) return Type::TOP; // Dead infinite loop
   return Type::CONTROL;
 }
 #ifndef PRODUCT
 void SafePointNode::dump_spec(outputStream *st) const {
   st->print(" SafePoint ");
 }
 #endif
 const RegMask &SafePointNode::in_RegMask(uint idx) const {
   if( idx < TypeFunc::Parms ) return RegMask::Empty;
   // Values outside the domain represent debug info
   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
 }
 const RegMask &SafePointNode::out_RegMask() const {
   return RegMask::Empty;
 }
 void SafePointNode::grow_stack(JVMState* jvms, uint grow_by) {
   assert((int)grow_by > 0, "sanity");
   int monoff = jvms->monoff();
   int scloff = jvms->scloff();
   int endoff = jvms->endoff();
   assert(endoff == (int)req(), "no other states or debug info after me");
   Node* top = Compile::current()->top();
   for (uint i = 0; i < grow_by; i++) {
     ins_req(monoff, top);
   }
   jvms->set_monoff(monoff + grow_by);
   jvms->set_scloff(scloff + grow_by);
   jvms->set_endoff(endoff + grow_by);
 }
 void SafePointNode::push_monitor(const FastLockNode *lock) {
   // Add a LockNode, which points to both the original BoxLockNode (the
   // stack space for the monitor) and the Object being locked.
   const int MonitorEdges = 2;
   assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
   assert(req() == jvms()->endoff(), "correct sizing");
   int nextmon = jvms()->scloff();
   if (GenerateSynchronizationCode) {
     add_req(lock->box_node());
     add_req(lock->obj_node());
   } else {
     Node* top = Compile::current()->top();
     add_req(top);
     add_req(top);
   }
   jvms()->set_scloff(nextmon+MonitorEdges);
   jvms()->set_endoff(req());
 }
 void SafePointNode::pop_monitor() {
   // Delete last monitor from debug info
   debug_only(int num_before_pop = jvms()->nof_monitors());
   const int MonitorEdges = (1<<JVMState::logMonitorEdges);
   int scloff = jvms()->scloff();
   int endoff = jvms()->endoff();
   int new_scloff = scloff - MonitorEdges;
   int new_endoff = endoff - MonitorEdges;
   jvms()->set_scloff(new_scloff);
   jvms()->set_endoff(new_endoff);
   while (scloff > new_scloff)  del_req(--scloff);
   assert(jvms()->nof_monitors() == num_before_pop-1, "");
 }
 Node *SafePointNode::peek_monitor_box() const {
   int mon = jvms()->nof_monitors() - 1;
   assert(mon >= 0, "most have a monitor");
   return monitor_box(jvms(), mon);
 }
 Node *SafePointNode::peek_monitor_obj() const {
   int mon = jvms()->nof_monitors() - 1;
   assert(mon >= 0, "most have a monitor");
   return monitor_obj(jvms(), mon);
 }
 // Do we Match on this edge index or not?  Match no edges
 uint SafePointNode::match_edge(uint idx) const {
   if( !needs_polling_address_input() )
     return 0;
   return (TypeFunc::Parms == idx);
 }
 //==============  SafePointScalarObjectNode  ==============
 SafePointScalarObjectNode::SafePointScalarObjectNode(const TypeOopPtr* tp,
 #ifdef ASSERT
                                                      AllocateNode* alloc,
 #endif
                                                      uint first_index,
                                                      uint n_fields) :
   TypeNode(tp, 1), // 1 control input -- seems required.  Get from root.
 #ifdef ASSERT
   _alloc(alloc),
 #endif
   _first_index(first_index),
   _n_fields(n_fields)
 {
   init_class_id(Class_SafePointScalarObject);
 }
 // Do not allow value-numbering for SafePointScalarObject node.
 uint SafePointScalarObjectNode::hash() const { return NO_HASH; }
 uint SafePointScalarObjectNode::cmp( const Node &n ) const {
   return (&n == this); // Always fail except on self
 }
 uint SafePointScalarObjectNode::ideal_reg() const {
   return 0; // No matching to machine instruction
 }
 const RegMask &SafePointScalarObjectNode::in_RegMask(uint idx) const {
   return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
 }
 const RegMask &SafePointScalarObjectNode::out_RegMask() const {
   return RegMask::Empty;
 }
 uint SafePointScalarObjectNode::match_edge(uint idx) const {
   return 0;
 }
 SafePointScalarObjectNode*
 SafePointScalarObjectNode::clone(int jvms_adj, Dict* sosn_map) const {
   void* cached = (*sosn_map)[(void*)this];
   if (cached != NULL) {
     return (SafePointScalarObjectNode*)cached;
   }
   SafePointScalarObjectNode* res = (SafePointScalarObjectNode*)Node::clone();
   res->_first_index += jvms_adj;
   sosn_map->Insert((void*)this, (void*)res);
   return res;
 }
 #ifndef PRODUCT
 void SafePointScalarObjectNode::dump_spec(outputStream *st) const {
   st->print(" # fields@[%d..%d]", first_index(),
              first_index() + n_fields() - 1);
 }
 #endif
 //=============================================================================
 uint AllocateNode::size_of() const { return sizeof(*this); }
 AllocateNode::AllocateNode(Compile* C, const TypeFunc *atype,
                            Node *ctrl, Node *mem, Node *abio,
                            Node *size, Node *klass_node, Node *initial_test)
   : CallNode(atype, NULL, TypeRawPtr::BOTTOM)
 {
   init_class_id(Class_Allocate);
   init_flags(Flag_is_macro);
   _is_scalar_replaceable = false;
   Node *topnode = C->top();
   init_req( TypeFunc::Control  , ctrl );
   init_req( TypeFunc::I_O      , abio );
   init_req( TypeFunc::Memory   , mem );
   init_req( TypeFunc::ReturnAdr, topnode );
   init_req( TypeFunc::FramePtr , topnode );
   init_req( AllocSize          , size);
   init_req( KlassNode          , klass_node);
   init_req( InitialTest        , initial_test);
   init_req( ALength            , topnode);
   C->add_macro_node(this);
 }
 //=============================================================================
 uint AllocateArrayNode::size_of() const { return sizeof(*this); }
 Node* AllocateArrayNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   if (remove_dead_region(phase, can_reshape))  return this;
   // Don't bother trying to transform a dead node
   if (in(0) && in(0)->is_top())  return NULL;
   const Type* type = phase->type(Ideal_length());
   if (type->isa_int() && type->is_int()->_hi < 0) {
     if (can_reshape) {
       PhaseIterGVN *igvn = phase->is_IterGVN();
       // Unreachable fall through path (negative array length),
       // the allocation can only throw so disconnect it.
       Node* proj = proj_out(TypeFunc::Control);
       Node* catchproj = NULL;
       if (proj != NULL) {
         for (DUIterator_Fast imax, i = proj->fast_outs(imax); i < imax; i++) {
           Node *cn = proj->fast_out(i);
           if (cn->is_Catch()) {
             catchproj = cn->as_Multi()->proj_out(CatchProjNode::fall_through_index);
             break;
           }
         }
       }
       if (catchproj != NULL && catchproj->outcnt() > 0 &&
           (catchproj->outcnt() > 1 ||
            catchproj->unique_out()->Opcode() != Op_Halt)) {
         assert(catchproj->is_CatchProj(), "must be a CatchProjNode");
         Node* nproj = catchproj->clone();
         igvn->register_new_node_with_optimizer(nproj);
         Node *frame = new (phase->C, 1) ParmNode( phase->C->start(), TypeFunc::FramePtr );
         frame = phase->transform(frame);
         // Halt & Catch Fire
         Node *halt = new (phase->C, TypeFunc::Parms) HaltNode( nproj, frame );
         phase->C->root()->add_req(halt);
         phase->transform(halt);
         igvn->replace_node(catchproj, phase->C->top());
         return this;
       }
     } else {
       // Can't correct it during regular GVN so register for IGVN
       phase->C->record_for_igvn(this);
     }
   }
   return NULL;
 }
 // Retrieve the length from the AllocateArrayNode. Narrow the type with a
 // CastII, if appropriate.  If we are not allowed to create new nodes, and
 // a CastII is appropriate, return NULL.
 Node *AllocateArrayNode::make_ideal_length(const TypeOopPtr* oop_type, PhaseTransform *phase, bool allow_new_nodes) {
   Node *length = in(AllocateNode::ALength);
   assert(length != NULL, "length is not null");
   const TypeInt* length_type = phase->find_int_type(length);
   const TypeAryPtr* ary_type = oop_type->isa_aryptr();
   if (ary_type != NULL && length_type != NULL) {
     const TypeInt* narrow_length_type = ary_type->narrow_size_type(length_type);
     if (narrow_length_type != length_type) {
       // Assert one of:
       //   - the narrow_length is 0
       //   - the narrow_length is not wider than length
       assert(narrow_length_type == TypeInt::ZERO ||
              (narrow_length_type->_hi <= length_type->_hi &&
               narrow_length_type->_lo >= length_type->_lo),
              "narrow type must be narrower than length type");
       // Return NULL if new nodes are not allowed
       if (!allow_new_nodes) return NULL;
       // Create a cast which is control dependent on the initialization to
       // propagate the fact that the array length must be positive.
       length = new (phase->C, 2) CastIINode(length, narrow_length_type);
       length->set_req(0, initialization()->proj_out(0));
     }
   }
   return length;
 }
 //=============================================================================
 uint LockNode::size_of() const { return sizeof(*this); }
 // Redundant lock elimination
 //
 // There are various patterns of locking where we release and
 // immediately reacquire a lock in a piece of code where no operations
 // occur in between that would be observable.  In those cases we can
 // skip releasing and reacquiring the lock without violating any
 // fairness requirements.  Doing this around a loop could cause a lock
 // to be held for a very long time so we concentrate on non-looping
 // control flow.  We also require that the operations are fully
 // redundant meaning that we don't introduce new lock operations on
 // some paths so to be able to eliminate it on others ala PRE.  This
 // would probably require some more extensive graph manipulation to
 // guarantee that the memory edges were all handled correctly.
 //
 // Assuming p is a simple predicate which can't trap in any way and s
 // is a synchronized method consider this code:
 //
 //   s();
 //   if (p)
 //     s();
 //   else
 //     s();
 //   s();
 //
 // 1. The unlocks of the first call to s can be eliminated if the
 // locks inside the then and else branches are eliminated.
 //
 // 2. The unlocks of the then and else branches can be eliminated if
 // the lock of the final call to s is eliminated.
 //
 // Either of these cases subsumes the simple case of sequential control flow
 //
 // Addtionally we can eliminate versions without the else case:
 //
 //   s();
 //   if (p)
 //     s();
 //   s();
 //
 // 3. In this case we eliminate the unlock of the first s, the lock
 // and unlock in the then case and the lock in the final s.
 //
 // Note also that in all these cases the then/else pieces don't have
 // to be trivial as long as they begin and end with synchronization
 // operations.
 //
 //   s();
 //   if (p)
 //     s();
 //     f();
 //     s();
 //   s();
 //
 // The code will work properly for this case, leaving in the unlock
 // before the call to f and the relock after it.
 //
 // A potentially interesting case which isn't handled here is when the
 // locking is partially redundant.
 //
 //   s();
 //   if (p)
 //     s();
 //
 // This could be eliminated putting unlocking on the else case and
 // eliminating the first unlock and the lock in the then side.
 // Alternatively the unlock could be moved out of the then side so it
 // was after the merge and the first unlock and second lock
 // eliminated.  This might require less manipulation of the memory
 // state to get correct.
 //
 // Additionally we might allow work between a unlock and lock before
 // giving up eliminating the locks.  The current code disallows any
 // conditional control flow between these operations.  A formulation
 // similar to partial redundancy elimination computing the
 // availability of unlocking and the anticipatability of locking at a
 // program point would allow detection of fully redundant locking with
 // some amount of work in between.  I'm not sure how often I really
 // think that would occur though.  Most of the cases I've seen
 // indicate it's likely non-trivial work would occur in between.
 // There may be other more complicated constructs where we could
 // eliminate locking but I haven't seen any others appear as hot or
 // interesting.
 //
 // Locking and unlocking have a canonical form in ideal that looks
 // roughly like this:
 //
 //              <obj>
 //                | \\------+
 //                |  \       \
 //                | BoxLock   \
 //                |  |   |     \
 //                |  |    \     \
 //                |  |   FastLock
 //                |  |   /
 //                |  |  /
 //                |  |  |
 //
 //               Lock
 //                |
 //            Proj #0
 //                |
 //            MembarAcquire
 //                |
 //            Proj #0
 //
 //            MembarRelease
 //                |
 //            Proj #0
 //                |
 //              Unlock
 //                |
 //            Proj #0
 //
 //
 // This code proceeds by processing Lock nodes during PhaseIterGVN
 // and searching back through its control for the proper code
 // patterns.  Once it finds a set of lock and unlock operations to
 // eliminate they are marked as eliminatable which causes the
 // expansion of the Lock and Unlock macro nodes to make the operation a NOP
 //
 //=============================================================================
 //
 // Utility function to skip over uninteresting control nodes.  Nodes skipped are:
 //   - copy regions.  (These may not have been optimized away yet.)
 //   - eliminated locking nodes
 //
 static Node *next_control(Node *ctrl) {
   if (ctrl == NULL)
     return NULL;
   while (1) {
     if (ctrl->is_Region()) {
       RegionNode *r = ctrl->as_Region();
       Node *n = r->is_copy();
       if (n == NULL)
         break;  // hit a region, return it
       else
         ctrl = n;
     } else if (ctrl->is_Proj()) {
       Node *in0 = ctrl->in(0);
       if (in0->is_AbstractLock() && in0->as_AbstractLock()->is_eliminated()) {
         ctrl = in0->in(0);
       } else {
         break;
       }
     } else {
       break; // found an interesting control
     }
   }
   return ctrl;
 }
 //
 // Given a control, see if it's the control projection of an Unlock which
 // operating on the same object as lock.
 //
 bool AbstractLockNode::find_matching_unlock(const Node* ctrl, LockNode* lock,
                                             GrowableArray<AbstractLockNode*> &lock_ops) {
   ProjNode *ctrl_proj = (ctrl->is_Proj()) ? ctrl->as_Proj() : NULL;
   if (ctrl_proj != NULL && ctrl_proj->_con == TypeFunc::Control) {
     Node *n = ctrl_proj->in(0);
     if (n != NULL && n->is_Unlock()) {
       UnlockNode *unlock = n->as_Unlock();
       if ((lock->obj_node() == unlock->obj_node()) &&
           (lock->box_node() == unlock->box_node()) && !unlock->is_eliminated()) {
         lock_ops.append(unlock);
         return true;
       }
     }
   }
   return false;
 }
 //
 // Find the lock matching an unlock.  Returns null if a safepoint
 // or complicated control is encountered first.
 LockNode *AbstractLockNode::find_matching_lock(UnlockNode* unlock) {
   LockNode *lock_result = NULL;
   // find the matching lock, or an intervening safepoint
   Node *ctrl = next_control(unlock->in(0));
   while (1) {
     assert(ctrl != NULL, "invalid control graph");
     assert(!ctrl->is_Start(), "missing lock for unlock");
     if (ctrl->is_top()) break;  // dead control path
     if (ctrl->is_Proj()) ctrl = ctrl->in(0);
     if (ctrl->is_SafePoint()) {
         break;  // found a safepoint (may be the lock we are searching for)
     } else if (ctrl->is_Region()) {
       // Check for a simple diamond pattern.  Punt on anything more complicated
       if (ctrl->req() == 3 && ctrl->in(1) != NULL && ctrl->in(2) != NULL) {
         Node *in1 = next_control(ctrl->in(1));
         Node *in2 = next_control(ctrl->in(2));
         if (((in1->is_IfTrue() && in2->is_IfFalse()) ||
              (in2->is_IfTrue() && in1->is_IfFalse())) && (in1->in(0) == in2->in(0))) {
           ctrl = next_control(in1->in(0)->in(0));
         } else {
           break;
         }
       } else {
         break;
       }
     } else {
       ctrl = next_control(ctrl->in(0));  // keep searching
     }
   }
   if (ctrl->is_Lock()) {
     LockNode *lock = ctrl->as_Lock();
     if ((lock->obj_node() == unlock->obj_node()) &&
             (lock->box_node() == unlock->box_node())) {
       lock_result = lock;
     }
   }
   return lock_result;
 }
 // This code corresponds to case 3 above.
 bool AbstractLockNode::find_lock_and_unlock_through_if(Node* node, LockNode* lock,
                                                        GrowableArray<AbstractLockNode*> &lock_ops) {
   Node* if_node = node->in(0);
   bool  if_true = node->is_IfTrue();
   if (if_node->is_If() && if_node->outcnt() == 2 && (if_true || node->is_IfFalse())) {
     Node *lock_ctrl = next_control(if_node->in(0));
     if (find_matching_unlock(lock_ctrl, lock, lock_ops)) {
       Node* lock1_node = NULL;
       ProjNode* proj = if_node->as_If()->proj_out(!if_true);
       if (if_true) {
         if (proj->is_IfFalse() && proj->outcnt() == 1) {
           lock1_node = proj->unique_out();
         }
       } else {
         if (proj->is_IfTrue() && proj->outcnt() == 1) {
           lock1_node = proj->unique_out();
         }
       }
       if (lock1_node != NULL && lock1_node->is_Lock()) {
         LockNode *lock1 = lock1_node->as_Lock();
         if ((lock->obj_node() == lock1->obj_node()) &&
             (lock->box_node() == lock1->box_node()) && !lock1->is_eliminated()) {
           lock_ops.append(lock1);
           return true;
         }
       }
     }
   }
   lock_ops.trunc_to(0);
   return false;
 }
 bool AbstractLockNode::find_unlocks_for_region(const RegionNode* region, LockNode* lock,
                                GrowableArray<AbstractLockNode*> &lock_ops) {
   // check each control merging at this point for a matching unlock.
   // in(0) should be self edge so skip it.
   for (int i = 1; i < (int)region->req(); i++) {
     Node *in_node = next_control(region->in(i));
     if (in_node != NULL) {
       if (find_matching_unlock(in_node, lock, lock_ops)) {
         // found a match so keep on checking.
         continue;
       } else if (find_lock_and_unlock_through_if(in_node, lock, lock_ops)) {
         continue;
       }
       // If we fall through to here then it was some kind of node we
       // don't understand or there wasn't a matching unlock, so give
       // up trying to merge locks.
       lock_ops.trunc_to(0);
       return false;
     }
   }
   return true;
 }
 #ifndef PRODUCT
 //
 // Create a counter which counts the number of times this lock is acquired
 //
 void AbstractLockNode::create_lock_counter(JVMState* state) {
   _counter = OptoRuntime::new_named_counter(state, NamedCounter::LockCounter);
 }
 #endif
 void AbstractLockNode::set_eliminated() {
   _eliminate = true;
 #ifndef PRODUCT
   if (_counter) {
     // Update the counter to indicate that this lock was eliminated.
     // The counter update code will stay around even though the
     // optimizer will eliminate the lock operation itself.
     _counter->set_tag(NamedCounter::EliminatedLockCounter);
   }
 #endif
 }
 //=============================================================================
 Node *LockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   // perform any generic optimizations first (returns 'this' or NULL)
   Node *result = SafePointNode::Ideal(phase, can_reshape);
   if (result != NULL)  return result;
   // Don't bother trying to transform a dead node
   if (in(0) && in(0)->is_top())  return NULL;
   // Now see if we can optimize away this lock.  We don't actually
   // remove the locking here, we simply set the _eliminate flag which
   // prevents macro expansion from expanding the lock.  Since we don't
   // modify the graph, the value returned from this function is the
   // one computed above.
   if (can_reshape && EliminateLocks && (!is_eliminated() || is_coarsened())) {
     //
     // If we are locking an unescaped object, the lock/unlock is unnecessary
     //
     ConnectionGraph *cgr = phase->C->congraph();
     PointsToNode::EscapeState es = PointsToNode::GlobalEscape;
     if (cgr != NULL)
       es = cgr->escape_state(obj_node());
     if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
       if (!is_eliminated()) {
         // Mark it eliminated to update any counters
         this->set_eliminated();
       } else {
         assert(is_coarsened(), "sanity");
         // The lock could be marked eliminated by lock coarsening
         // code during first IGVN before EA. Clear coarsened flag
         // to eliminate all associated locks/unlocks.
         this->clear_coarsened();
       }
       return result;
     }
     //
     // Try lock coarsening
     //
     PhaseIterGVN* iter = phase->is_IterGVN();
     if (iter != NULL && !is_eliminated()) {
       GrowableArray<AbstractLockNode*>   lock_ops;
       Node *ctrl = next_control(in(0));
       // now search back for a matching Unlock
       if (find_matching_unlock(ctrl, this, lock_ops)) {
         // found an unlock directly preceding this lock.  This is the
         // case of single unlock directly control dependent on a
         // single lock which is the trivial version of case 1 or 2.
       } else if (ctrl->is_Region() ) {
         if (find_unlocks_for_region(ctrl->as_Region(), this, lock_ops)) {
         // found lock preceded by multiple unlocks along all paths
         // joining at this point which is case 3 in description above.
         }
       } else {
         // see if this lock comes from either half of an if and the
         // predecessors merges unlocks and the other half of the if
         // performs a lock.
         if (find_lock_and_unlock_through_if(ctrl, this, lock_ops)) {
           // found unlock splitting to an if with locks on both branches.
         }
       }
       if (lock_ops.length() > 0) {
         // add ourselves to the list of locks to be eliminated.
         lock_ops.append(this);
   #ifndef PRODUCT
         if (PrintEliminateLocks) {
           int locks = 0;
           int unlocks = 0;
           for (int i = 0; i < lock_ops.length(); i++) {
             AbstractLockNode* lock = lock_ops.at(i);
             if (lock->Opcode() == Op_Lock)
               locks++;
             else
               unlocks++;
             if (Verbose) {
               lock->dump(1);
             }
           }
           tty->print_cr("***Eliminated %d unlocks and %d locks", unlocks, locks);
         }
   #endif
         // for each of the identified locks, mark them
         // as eliminatable
         for (int i = 0; i < lock_ops.length(); i++) {
           AbstractLockNode* lock = lock_ops.at(i);
           // Mark it eliminated to update any counters
           lock->set_eliminated();
           lock->set_coarsened();
         }
       } else if (ctrl->is_Region() &&
                  iter->_worklist.member(ctrl)) {
         // We weren't able to find any opportunities but the region this
         // lock is control dependent on hasn't been processed yet so put
         // this lock back on the worklist so we can check again once any
         // region simplification has occurred.
         iter->_worklist.push(this);
       }
     }
   }
   return result;
 }
 //=============================================================================
 uint UnlockNode::size_of() const { return sizeof(*this); }
 //=============================================================================
 Node *UnlockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   // perform any generic optimizations first (returns 'this' or NULL)
   Node *result = SafePointNode::Ideal(phase, can_reshape);
   if (result != NULL)  return result;
   // Don't bother trying to transform a dead node
   if (in(0) && in(0)->is_top())  return NULL;
   // Now see if we can optimize away this unlock.  We don't actually
   // remove the unlocking here, we simply set the _eliminate flag which
   // prevents macro expansion from expanding the unlock.  Since we don't
   // modify the graph, the value returned from this function is the
   // one computed above.
   // Escape state is defined after Parse phase.
   if (can_reshape && EliminateLocks && (!is_eliminated() || is_coarsened())) {
     //
     // If we are unlocking an unescaped object, the lock/unlock is unnecessary.
     //
     ConnectionGraph *cgr = phase->C->congraph();
     PointsToNode::EscapeState es = PointsToNode::GlobalEscape;
     if (cgr != NULL)
       es = cgr->escape_state(obj_node());
     if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
       if (!is_eliminated()) {
         // Mark it eliminated to update any counters
         this->set_eliminated();
       } else {
         assert(is_coarsened(), "sanity");
         // The lock could be marked eliminated by lock coarsening
         // code during first IGVN before EA. Clear coarsened flag
         // to eliminate all associated locks/unlocks.
         this->clear_coarsened();
       }
     }
   }
   return result;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/callnode.cpp@1bd45abaa507 (annotated)

src/share/vm/opto/callnode.cpp