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 /*

  * Copyright 1997-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 // Portions of code courtesy of Clifford Click

 // Optimization - Graph Style

 #include "incls/_precompiled.incl"

 #include "incls/_type.cpp.incl"

 // Dictionary of types shared among compilations.

 Dict* Type::_shared_type_dict = NULL;

 // Array which maps compiler types to Basic Types

 const BasicType Type::_basic_type[Type::lastype] = {

   T_ILLEGAL,    // Bad

   T_ILLEGAL,    // Control

   T_VOID,       // Top

   T_INT,        // Int

   T_LONG,       // Long

   T_VOID,       // Half

   T_NARROWOOP,  // NarrowOop

   T_ILLEGAL,    // Tuple

   T_ARRAY,      // Array

   T_ADDRESS,    // AnyPtr   // shows up in factory methods for NULL_PTR

   T_ADDRESS,    // RawPtr

   T_OBJECT,     // OopPtr

   T_OBJECT,     // InstPtr

   T_OBJECT,     // AryPtr

   T_OBJECT,     // KlassPtr

   T_OBJECT,     // Function

   T_ILLEGAL,    // Abio

   T_ADDRESS,    // Return_Address

   T_ILLEGAL,    // Memory

   T_FLOAT,      // FloatTop

   T_FLOAT,      // FloatCon

   T_FLOAT,      // FloatBot

   T_DOUBLE,     // DoubleTop

   T_DOUBLE,     // DoubleCon

   T_DOUBLE,     // DoubleBot

   T_ILLEGAL,    // Bottom

 };

 // Map ideal registers (machine types) to ideal types

 const Type *Type::mreg2type[_last_machine_leaf];

 // Map basic types to canonical Type* pointers.

 const Type* Type::     _const_basic_type[T_CONFLICT+1];

 // Map basic types to constant-zero Types.

 const Type* Type::            _zero_type[T_CONFLICT+1];

 // Map basic types to array-body alias types.

 const TypeAryPtr* TypeAryPtr::_array_body_type[T_CONFLICT+1];

 //=============================================================================

 // Convenience common pre-built types.

 const Type *Type::ABIO;         // State-of-machine only

 const Type *Type::BOTTOM;       // All values

 const Type *Type::CONTROL;      // Control only

 const Type *Type::DOUBLE;       // All doubles

 const Type *Type::FLOAT;        // All floats

 const Type *Type::HALF;         // Placeholder half of doublewide type

 const Type *Type::MEMORY;       // Abstract store only

 const Type *Type::RETURN_ADDRESS;

 const Type *Type::TOP;          // No values in set

 //------------------------------get_const_type---------------------------

 const Type* Type::get_const_type(ciType* type) {

   if (type == NULL) {

     return NULL;

   } else if (type->is_primitive_type()) {

     return get_const_basic_type(type->basic_type());

   } else {

     return TypeOopPtr::make_from_klass(type->as_klass());

   }

 }

 //---------------------------array_element_basic_type---------------------------------

 // Mapping to the array element's basic type.

 BasicType Type::array_element_basic_type() const {

   BasicType bt = basic_type();

   if (bt == T_INT) {

     if (this == TypeInt::INT)   return T_INT;

     if (this == TypeInt::CHAR)  return T_CHAR;

     if (this == TypeInt::BYTE)  return T_BYTE;

     if (this == TypeInt::BOOL)  return T_BOOLEAN;

     if (this == TypeInt::SHORT) return T_SHORT;

     return T_VOID;

   }

   return bt;

 }

 //---------------------------get_typeflow_type---------------------------------

 // Import a type produced by ciTypeFlow.

 const Type* Type::get_typeflow_type(ciType* type) {

   switch (type->basic_type()) {

   case ciTypeFlow::StateVector::T_BOTTOM:

     assert(type == ciTypeFlow::StateVector::bottom_type(), "");

     return Type::BOTTOM;

   case ciTypeFlow::StateVector::T_TOP:

     assert(type == ciTypeFlow::StateVector::top_type(), "");

     return Type::TOP;

   case ciTypeFlow::StateVector::T_NULL:

     assert(type == ciTypeFlow::StateVector::null_type(), "");

     return TypePtr::NULL_PTR;

   case ciTypeFlow::StateVector::T_LONG2:

     // The ciTypeFlow pass pushes a long, then the half.

     // We do the same.

     assert(type == ciTypeFlow::StateVector::long2_type(), "");

     return TypeInt::TOP;

   case ciTypeFlow::StateVector::T_DOUBLE2:

     // The ciTypeFlow pass pushes double, then the half.

     // Our convention is the same.

     assert(type == ciTypeFlow::StateVector::double2_type(), "");

     return Type::TOP;

   case T_ADDRESS:

     assert(type->is_return_address(), "");

     return TypeRawPtr::make((address)(intptr_t)type->as_return_address()->bci());

   default:

     // make sure we did not mix up the cases:

     assert(type != ciTypeFlow::StateVector::bottom_type(), "");

     assert(type != ciTypeFlow::StateVector::top_type(), "");

     assert(type != ciTypeFlow::StateVector::null_type(), "");

     assert(type != ciTypeFlow::StateVector::long2_type(), "");

     assert(type != ciTypeFlow::StateVector::double2_type(), "");

     assert(!type->is_return_address(), "");

     return Type::get_const_type(type);

   }

 }

 //------------------------------make-------------------------------------------

 // Create a simple Type, with default empty symbol sets.  Then hashcons it

 // and look for an existing copy in the type dictionary.

 const Type *Type::make( enum TYPES t ) {

   return (new Type(t))->hashcons();

 }

 //------------------------------cmp--------------------------------------------

 int Type::cmp( const Type *const t1, const Type *const t2 ) {

   if( t1->_base != t2->_base )

     return 1;                   // Missed badly

   assert(t1 != t2 || t1->eq(t2), "eq must be reflexive");

   return !t1->eq(t2);           // Return ZERO if equal

 }

 //------------------------------hash-------------------------------------------

 int Type::uhash( const Type *const t ) {

   return t->hash();

 }

 //--------------------------Initialize_shared----------------------------------

 void Type::Initialize_shared(Compile* current) {

   // This method does not need to be locked because the first system

   // compilations (stub compilations) occur serially.  If they are

   // changed to proceed in parallel, then this section will need

   // locking.

   Arena* save = current->type_arena();

   Arena* shared_type_arena = new Arena();

   current->set_type_arena(shared_type_arena);

   _shared_type_dict =

     new (shared_type_arena) Dict( (CmpKey)Type::cmp, (Hash)Type::uhash,

                                   shared_type_arena, 128 );

   current->set_type_dict(_shared_type_dict);

   // Make shared pre-built types.

   CONTROL = make(Control);      // Control only

   TOP     = make(Top);          // No values in set

   MEMORY  = make(Memory);       // Abstract store only

   ABIO    = make(Abio);         // State-of-machine only

   RETURN_ADDRESS=make(Return_Address);

   FLOAT   = make(FloatBot);     // All floats

   DOUBLE  = make(DoubleBot);    // All doubles

   BOTTOM  = make(Bottom);       // Everything

   HALF    = make(Half);         // Placeholder half of doublewide type

   TypeF::ZERO = TypeF::make(0.0); // Float 0 (positive zero)

   TypeF::ONE  = TypeF::make(1.0); // Float 1

   TypeD::ZERO = TypeD::make(0.0); // Double 0 (positive zero)

   TypeD::ONE  = TypeD::make(1.0); // Double 1

   TypeInt::MINUS_1 = TypeInt::make(-1);  // -1

   TypeInt::ZERO    = TypeInt::make( 0);  //  0

   TypeInt::ONE     = TypeInt::make( 1);  //  1

   TypeInt::BOOL    = TypeInt::make(0,1,   WidenMin);  // 0 or 1, FALSE or TRUE.

   TypeInt::CC      = TypeInt::make(-1, 1, WidenMin);  // -1, 0 or 1, condition codes

   TypeInt::CC_LT   = TypeInt::make(-1,-1, WidenMin);  // == TypeInt::MINUS_1

   TypeInt::CC_GT   = TypeInt::make( 1, 1, WidenMin);  // == TypeInt::ONE

   TypeInt::CC_EQ   = TypeInt::make( 0, 0, WidenMin);  // == TypeInt::ZERO

   TypeInt::CC_LE   = TypeInt::make(-1, 0, WidenMin);

   TypeInt::CC_GE   = TypeInt::make( 0, 1, WidenMin);  // == TypeInt::BOOL

   TypeInt::BYTE    = TypeInt::make(-128,127,     WidenMin); // Bytes

   TypeInt::CHAR    = TypeInt::make(0,65535,      WidenMin); // Java chars

   TypeInt::SHORT   = TypeInt::make(-32768,32767, WidenMin); // Java shorts

   TypeInt::POS     = TypeInt::make(0,max_jint,   WidenMin); // Non-neg values

   TypeInt::POS1    = TypeInt::make(1,max_jint,   WidenMin); // Positive values

   TypeInt::INT     = TypeInt::make(min_jint,max_jint, WidenMax); // 32-bit integers

   TypeInt::SYMINT  = TypeInt::make(-max_jint,max_jint,WidenMin); // symmetric range

   // CmpL is overloaded both as the bytecode computation returning

   // a trinary (-1,0,+1) integer result AND as an efficient long

   // compare returning optimizer ideal-type flags.

   assert( TypeInt::CC_LT == TypeInt::MINUS_1, "types must match for CmpL to work" );

   assert( TypeInt::CC_GT == TypeInt::ONE,     "types must match for CmpL to work" );

   assert( TypeInt::CC_EQ == TypeInt::ZERO,    "types must match for CmpL to work" );

   assert( TypeInt::CC_GE == TypeInt::BOOL,    "types must match for CmpL to work" );

   TypeLong::MINUS_1 = TypeLong::make(-1);        // -1

   TypeLong::ZERO    = TypeLong::make( 0);        //  0

   TypeLong::ONE     = TypeLong::make( 1);        //  1

   TypeLong::POS     = TypeLong::make(0,max_jlong, WidenMin); // Non-neg values

   TypeLong::LONG    = TypeLong::make(min_jlong,max_jlong,WidenMax); // 64-bit integers

   TypeLong::INT     = TypeLong::make((jlong)min_jint,(jlong)max_jint,WidenMin);

   TypeLong::UINT    = TypeLong::make(0,(jlong)max_juint,WidenMin);

   const Type **fboth =(const Type**)shared_type_arena->Amalloc_4(2*sizeof(Type*));

   fboth[0] = Type::CONTROL;

   fboth[1] = Type::CONTROL;

   TypeTuple::IFBOTH = TypeTuple::make( 2, fboth );

   const Type **ffalse =(const Type**)shared_type_arena->Amalloc_4(2*sizeof(Type*));

   ffalse[0] = Type::CONTROL;

   ffalse[1] = Type::TOP;

   TypeTuple::IFFALSE = TypeTuple::make( 2, ffalse );

   const Type **fneither =(const Type**)shared_type_arena->Amalloc_4(2*sizeof(Type*));

   fneither[0] = Type::TOP;

   fneither[1] = Type::TOP;

   TypeTuple::IFNEITHER = TypeTuple::make( 2, fneither );

   const Type **ftrue =(const Type**)shared_type_arena->Amalloc_4(2*sizeof(Type*));

   ftrue[0] = Type::TOP;

   ftrue[1] = Type::CONTROL;

   TypeTuple::IFTRUE = TypeTuple::make( 2, ftrue );

   const Type **floop =(const Type**)shared_type_arena->Amalloc_4(2*sizeof(Type*));

   floop[0] = Type::CONTROL;

   floop[1] = TypeInt::INT;

   TypeTuple::LOOPBODY = TypeTuple::make( 2, floop );

   TypePtr::NULL_PTR= TypePtr::make( AnyPtr, TypePtr::Null, 0 );

   TypePtr::NOTNULL = TypePtr::make( AnyPtr, TypePtr::NotNull, OffsetBot );

   TypePtr::BOTTOM  = TypePtr::make( AnyPtr, TypePtr::BotPTR, OffsetBot );

   TypeRawPtr::BOTTOM = TypeRawPtr::make( TypePtr::BotPTR );

   TypeRawPtr::NOTNULL= TypeRawPtr::make( TypePtr::NotNull );

   const Type **fmembar = TypeTuple::fields(0);

   TypeTuple::MEMBAR = TypeTuple::make(TypeFunc::Parms+0, fmembar);

   const Type **fsc = (const Type**)shared_type_arena->Amalloc_4(2*sizeof(Type*));

   fsc[0] = TypeInt::CC;

   fsc[1] = Type::MEMORY;

   TypeTuple::STORECONDITIONAL = TypeTuple::make(2, fsc);

   TypeInstPtr::NOTNULL = TypeInstPtr::make(TypePtr::NotNull, current->env()->Object_klass());

   TypeInstPtr::BOTTOM  = TypeInstPtr::make(TypePtr::BotPTR,  current->env()->Object_klass());

   TypeInstPtr::MIRROR  = TypeInstPtr::make(TypePtr::NotNull, current->env()->Class_klass());

   TypeInstPtr::MARK    = TypeInstPtr::make(TypePtr::BotPTR,  current->env()->Object_klass(),

                                            false, 0, oopDesc::mark_offset_in_bytes());

   TypeInstPtr::KLASS   = TypeInstPtr::make(TypePtr::BotPTR,  current->env()->Object_klass(),

                                            false, 0, oopDesc::klass_offset_in_bytes());

   TypeOopPtr::BOTTOM  = TypeOopPtr::make(TypePtr::BotPTR, OffsetBot);

   TypeNarrowOop::NULL_PTR = TypeNarrowOop::make( TypePtr::NULL_PTR );

   TypeNarrowOop::BOTTOM   = TypeNarrowOop::make( TypeInstPtr::BOTTOM );

   mreg2type[Op_Node] = Type::BOTTOM;

   mreg2type[Op_Set ] = 0;

   mreg2type[Op_RegN] = TypeNarrowOop::BOTTOM;

   mreg2type[Op_RegI] = TypeInt::INT;

   mreg2type[Op_RegP] = TypePtr::BOTTOM;

   mreg2type[Op_RegF] = Type::FLOAT;

   mreg2type[Op_RegD] = Type::DOUBLE;

   mreg2type[Op_RegL] = TypeLong::LONG;

   mreg2type[Op_RegFlags] = TypeInt::CC;

   TypeAryPtr::RANGE   = TypeAryPtr::make( TypePtr::BotPTR, TypeAry::make(Type::BOTTOM,TypeInt::POS), current->env()->Object_klass(), false, arrayOopDesc::length_offset_in_bytes());

   // There is no shared klass for Object[].  See note in TypeAryPtr::klass().

   TypeAryPtr::OOPS    = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(TypeInstPtr::BOTTOM,TypeInt::POS), NULL /*ciArrayKlass::make(o)*/,  false,  Type::OffsetBot);

   TypeAryPtr::BYTES   = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(TypeInt::BYTE      ,TypeInt::POS), ciTypeArrayKlass::make(T_BYTE),   true,  Type::OffsetBot);

   TypeAryPtr::SHORTS  = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(TypeInt::SHORT     ,TypeInt::POS), ciTypeArrayKlass::make(T_SHORT),  true,  Type::OffsetBot);

   TypeAryPtr::CHARS   = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(TypeInt::CHAR      ,TypeInt::POS), ciTypeArrayKlass::make(T_CHAR),   true,  Type::OffsetBot);

   TypeAryPtr::INTS    = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(TypeInt::INT       ,TypeInt::POS), ciTypeArrayKlass::make(T_INT),    true,  Type::OffsetBot);

   TypeAryPtr::LONGS   = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(TypeLong::LONG     ,TypeInt::POS), ciTypeArrayKlass::make(T_LONG),   true,  Type::OffsetBot);

   TypeAryPtr::FLOATS  = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(Type::FLOAT        ,TypeInt::POS), ciTypeArrayKlass::make(T_FLOAT),  true,  Type::OffsetBot);

   TypeAryPtr::DOUBLES = TypeAryPtr::make(TypePtr::BotPTR, TypeAry::make(Type::DOUBLE       ,TypeInt::POS), ciTypeArrayKlass::make(T_DOUBLE), true,  Type::OffsetBot);

   TypeAryPtr::_array_body_type[T_NARROWOOP] = NULL; // what should this be?

   TypeAryPtr::_array_body_type[T_OBJECT]  = TypeAryPtr::OOPS;

   TypeAryPtr::_array_body_type[T_ARRAY]   = TypeAryPtr::OOPS;   // arrays are stored in oop arrays

   TypeAryPtr::_array_body_type[T_BYTE]    = TypeAryPtr::BYTES;

   TypeAryPtr::_array_body_type[T_BOOLEAN] = TypeAryPtr::BYTES;  // boolean[] is a byte array

   TypeAryPtr::_array_body_type[T_SHORT]   = TypeAryPtr::SHORTS;

   TypeAryPtr::_array_body_type[T_CHAR]    = TypeAryPtr::CHARS;

   TypeAryPtr::_array_body_type[T_INT]     = TypeAryPtr::INTS;

   TypeAryPtr::_array_body_type[T_LONG]    = TypeAryPtr::LONGS;

   TypeAryPtr::_array_body_type[T_FLOAT]   = TypeAryPtr::FLOATS;

   TypeAryPtr::_array_body_type[T_DOUBLE]  = TypeAryPtr::DOUBLES;

   TypeKlassPtr::OBJECT = TypeKlassPtr::make( TypePtr::NotNull, current->env()->Object_klass(), 0 );

   TypeKlassPtr::OBJECT_OR_NULL = TypeKlassPtr::make( TypePtr::BotPTR, current->env()->Object_klass(), 0 );

   const Type **fi2c = TypeTuple::fields(2);

   fi2c[TypeFunc::Parms+0] = TypeInstPtr::BOTTOM; // methodOop

   fi2c[TypeFunc::Parms+1] = TypeRawPtr::BOTTOM; // argument pointer

   TypeTuple::START_I2C = TypeTuple::make(TypeFunc::Parms+2, fi2c);

   const Type **intpair = TypeTuple::fields(2);

   intpair[0] = TypeInt::INT;

   intpair[1] = TypeInt::INT;

   TypeTuple::INT_PAIR = TypeTuple::make(2, intpair);

   const Type **longpair = TypeTuple::fields(2);

   longpair[0] = TypeLong::LONG;

   longpair[1] = TypeLong::LONG;

   TypeTuple::LONG_PAIR = TypeTuple::make(2, longpair);

   _const_basic_type[T_NARROWOOP] = TypeNarrowOop::BOTTOM;

   _const_basic_type[T_BOOLEAN] = TypeInt::BOOL;

   _const_basic_type[T_CHAR]    = TypeInt::CHAR;

   _const_basic_type[T_BYTE]    = TypeInt::BYTE;

   _const_basic_type[T_SHORT]   = TypeInt::SHORT;

   _const_basic_type[T_INT]     = TypeInt::INT;

   _const_basic_type[T_LONG]    = TypeLong::LONG;

   _const_basic_type[T_FLOAT]   = Type::FLOAT;

   _const_basic_type[T_DOUBLE]  = Type::DOUBLE;

   _const_basic_type[T_OBJECT]  = TypeInstPtr::BOTTOM;

   _const_basic_type[T_ARRAY]   = TypeInstPtr::BOTTOM; // there is no separate bottom for arrays

   _const_basic_type[T_VOID]    = TypePtr::NULL_PTR;   // reflection represents void this way

   _const_basic_type[T_ADDRESS] = TypeRawPtr::BOTTOM;  // both interpreter return addresses & random raw ptrs

   _const_basic_type[T_CONFLICT]= Type::BOTTOM;        // why not?

   _zero_type[T_NARROWOOP] = TypeNarrowOop::NULL_PTR;

   _zero_type[T_BOOLEAN] = TypeInt::ZERO;     // false == 0

   _zero_type[T_CHAR]    = TypeInt::ZERO;     // '\0' == 0

   _zero_type[T_BYTE]    = TypeInt::ZERO;     // 0x00 == 0

   _zero_type[T_SHORT]   = TypeInt::ZERO;     // 0x0000 == 0

   _zero_type[T_INT]     = TypeInt::ZERO;

   _zero_type[T_LONG]    = TypeLong::ZERO;

   _zero_type[T_FLOAT]   = TypeF::ZERO;

   _zero_type[T_DOUBLE]  = TypeD::ZERO;

   _zero_type[T_OBJECT]  = TypePtr::NULL_PTR;

   _zero_type[T_ARRAY]   = TypePtr::NULL_PTR; // null array is null oop

   _zero_type[T_ADDRESS] = TypePtr::NULL_PTR; // raw pointers use the same null

   _zero_type[T_VOID]    = Type::TOP;         // the only void value is no value at all

   // get_zero_type() should not happen for T_CONFLICT

   _zero_type[T_CONFLICT]= NULL;

   // Restore working type arena.

   current->set_type_arena(save);

   current->set_type_dict(NULL);

 }

 //------------------------------Initialize-------------------------------------

 void Type::Initialize(Compile* current) {

   assert(current->type_arena() != NULL, "must have created type arena");

   if (_shared_type_dict == NULL) {

     Initialize_shared(current);

   }

   Arena* type_arena = current->type_arena();

   // Create the hash-cons'ing dictionary with top-level storage allocation

   Dict *tdic = new (type_arena) Dict( (CmpKey)Type::cmp,(Hash)Type::uhash, type_arena, 128 );

   current->set_type_dict(tdic);

   // Transfer the shared types.

   DictI i(_shared_type_dict);

   for( ; i.test(); ++i ) {

     Type* t = (Type*)i._value;

     tdic->Insert(t,t);  // New Type, insert into Type table

   }

 #ifdef ASSERT

   verify_lastype();

 #endif

 }

 //------------------------------hashcons---------------------------------------

 // Do the hash-cons trick.  If the Type already exists in the type table,

 // delete the current Type and return the existing Type.  Otherwise stick the

 // current Type in the Type table.

 const Type *Type::hashcons(void) {

   debug_only(base());           // Check the assertion in Type::base().

   // Look up the Type in the Type dictionary

   Dict *tdic = type_dict();

   Type* old = (Type*)(tdic->Insert(this, this, false));

   if( old ) {                   // Pre-existing Type?

     if( old != this )           // Yes, this guy is not the pre-existing?

       delete this;              // Yes, Nuke this guy

     assert( old->_dual, "" );

     return old;                 // Return pre-existing

   }

   // Every type has a dual (to make my lattice symmetric).

   // Since we just discovered a new Type, compute its dual right now.

   assert( !_dual, "" );         // No dual yet

   _dual = xdual();              // Compute the dual

   if( cmp(this,_dual)==0 ) {    // Handle self-symmetric

     _dual = this;

     return this;

   }

   assert( !_dual->_dual, "" );  // No reverse dual yet

   assert( !(*tdic)[_dual], "" ); // Dual not in type system either

   // New Type, insert into Type table

   tdic->Insert((void*)_dual,(void*)_dual);

   ((Type*)_dual)->_dual = this; // Finish up being symmetric

 #ifdef ASSERT

   Type *dual_dual = (Type*)_dual->xdual();

   assert( eq(dual_dual), "xdual(xdual()) should be identity" );

   delete dual_dual;

 #endif

   return this;                  // Return new Type

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool Type::eq( const Type * ) const {

   return true;                  // Nothing else can go wrong

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int Type::hash(void) const {

   return _base;

 }

 //------------------------------is_finite--------------------------------------

 // Has a finite value

 bool Type::is_finite() const {

   return false;

 }

 //------------------------------is_nan-----------------------------------------

 // Is not a number (NaN)

 bool Type::is_nan()    const {

   return false;

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  NOT virtual.  It enforces that meet is

 // commutative and the lattice is symmetric.

 const Type *Type::meet( const Type *t ) const {

   if (isa_narrowoop() && t->isa_narrowoop()) {

     const Type* result = is_narrowoop()->make_oopptr()->meet(t->is_narrowoop()->make_oopptr());

     if (result->isa_oopptr()) {

       return result->isa_oopptr()->make_narrowoop();

     } else if (result == TypePtr::NULL_PTR) {

       return TypeNarrowOop::NULL_PTR;

     } else {

       return result;

     }

   }

   const Type *mt = xmeet(t);

   if (isa_narrowoop() || t->isa_narrowoop()) return mt;

 #ifdef ASSERT

   assert( mt == t->xmeet(this), "meet not commutative" );

   const Type* dual_join = mt->_dual;

   const Type *t2t    = dual_join->xmeet(t->_dual);

   const Type *t2this = dual_join->xmeet(   _dual);

   // Interface meet Oop is Not Symmetric:

   // Interface:AnyNull meet Oop:AnyNull == Interface:AnyNull

   // Interface:NotNull meet Oop:NotNull == java/lang/Object:NotNull

   const TypeInstPtr* this_inst = this->isa_instptr();

   const TypeInstPtr*    t_inst =    t->isa_instptr();

   bool interface_vs_oop = false;

   if( this_inst && this_inst->is_loaded() && t_inst && t_inst->is_loaded() ) {

     bool this_interface = this_inst->klass()->is_interface();

     bool    t_interface =    t_inst->klass()->is_interface();

     interface_vs_oop = this_interface ^ t_interface;

   }

   const Type *tdual = t->_dual;

   const Type *thisdual = _dual;

   // strip out instances

   if (t2t->isa_oopptr() != NULL) {

     t2t = t2t->isa_oopptr()->cast_to_instance(TypeOopPtr::UNKNOWN_INSTANCE);

   }

   if (t2this->isa_oopptr() != NULL) {

     t2this = t2this->isa_oopptr()->cast_to_instance(TypeOopPtr::UNKNOWN_INSTANCE);

   }

   if (tdual->isa_oopptr() != NULL) {

     tdual = tdual->isa_oopptr()->cast_to_instance(TypeOopPtr::UNKNOWN_INSTANCE);

   }

   if (thisdual->isa_oopptr() != NULL) {

     thisdual = thisdual->isa_oopptr()->cast_to_instance(TypeOopPtr::UNKNOWN_INSTANCE);

   }

   if( !interface_vs_oop && (t2t != tdual || t2this != thisdual) ) {

     tty->print_cr("=== Meet Not Symmetric ===");

     tty->print("t   =                   ");         t->dump(); tty->cr();

     tty->print("this=                   ");            dump(); tty->cr();

     tty->print("mt=(t meet this)=       ");        mt->dump(); tty->cr();

     tty->print("t_dual=                 ");  t->_dual->dump(); tty->cr();

     tty->print("this_dual=              ");     _dual->dump(); tty->cr();

     tty->print("mt_dual=                "); mt->_dual->dump(); tty->cr();

     tty->print("mt_dual meet t_dual=    "); t2t      ->dump(); tty->cr();

     tty->print("mt_dual meet this_dual= "); t2this   ->dump(); tty->cr();

     fatal("meet not symmetric" );

   }

 #endif

   return mt;

 }

 //------------------------------xmeet------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *Type::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Meeting TOP with anything?

   if( _base == Top ) return t;

   // Meeting BOTTOM with anything?

   if( _base == Bottom ) return BOTTOM;

   // Current "this->_base" is one of: Bad, Multi, Control, Top,

   // Abio, Abstore, Floatxxx, Doublexxx, Bottom, lastype.

   switch (t->base()) {  // Switch on original type

   // Cut in half the number of cases I must handle.  Only need cases for when

   // the given enum "t->type" is less than or equal to the local enum "type".

   case FloatCon:

   case DoubleCon:

   case Int:

   case Long:

     return t->xmeet(this);

   case OopPtr:

     return t->xmeet(this);

   case InstPtr:

     return t->xmeet(this);

   case KlassPtr:

     return t->xmeet(this);

   case AryPtr:

     return t->xmeet(this);

   case NarrowOop:

     return t->xmeet(this);

   case Bad:                     // Type check

   default:                      // Bogus type not in lattice

     typerr(t);

     return Type::BOTTOM;

   case Bottom:                  // Ye Olde Default

     return t;

   case FloatTop:

     if( _base == FloatTop ) return this;

   case FloatBot:                // Float

     if( _base == FloatBot || _base == FloatTop ) return FLOAT;

     if( _base == DoubleTop || _base == DoubleBot ) return Type::BOTTOM;

     typerr(t);

     return Type::BOTTOM;

   case DoubleTop:

     if( _base == DoubleTop ) return this;

   case DoubleBot:               // Double

     if( _base == DoubleBot || _base == DoubleTop ) return DOUBLE;

     if( _base == FloatTop || _base == FloatBot ) return Type::BOTTOM;

     typerr(t);

     return Type::BOTTOM;

   // These next few cases must match exactly or it is a compile-time error.

   case Control:                 // Control of code

   case Abio:                    // State of world outside of program

   case Memory:

     if( _base == t->_base )  return this;

     typerr(t);

     return Type::BOTTOM;

   case Top:                     // Top of the lattice

     return this;

   }

   // The type is unchanged

   return this;

 }

 //-----------------------------filter------------------------------------------

 const Type *Type::filter( const Type *kills ) const {

   const Type* ft = join(kills);

   if (ft->empty())

     return Type::TOP;           // Canonical empty value

   return ft;

 }

 //------------------------------xdual------------------------------------------

 // Compute dual right now.

 const Type::TYPES Type::dual_type[Type::lastype] = {

   Bad,          // Bad

   Control,      // Control

   Bottom,       // Top

   Bad,          // Int - handled in v-call

   Bad,          // Long - handled in v-call

   Half,         // Half

   Bad,          // NarrowOop - handled in v-call

   Bad,          // Tuple - handled in v-call

   Bad,          // Array - handled in v-call

   Bad,          // AnyPtr - handled in v-call

   Bad,          // RawPtr - handled in v-call

   Bad,          // OopPtr - handled in v-call

   Bad,          // InstPtr - handled in v-call

   Bad,          // AryPtr - handled in v-call

   Bad,          // KlassPtr - handled in v-call

   Bad,          // Function - handled in v-call

   Abio,         // Abio

   Return_Address,// Return_Address

   Memory,       // Memory

   FloatBot,     // FloatTop

   FloatCon,     // FloatCon

   FloatTop,     // FloatBot

   DoubleBot,    // DoubleTop

   DoubleCon,    // DoubleCon

   DoubleTop,    // DoubleBot

   Top           // Bottom

 };

 const Type *Type::xdual() const {

   // Note: the base() accessor asserts the sanity of _base.

   assert(dual_type[base()] != Bad, "implement with v-call");

   return new Type(dual_type[_base]);

 }

 //------------------------------has_memory-------------------------------------

 bool Type::has_memory() const {

   Type::TYPES tx = base();

   if (tx == Memory) return true;

   if (tx == Tuple) {

     const TypeTuple *t = is_tuple();

     for (uint i=0; i < t->cnt(); i++) {

       tx = t->field_at(i)->base();

       if (tx == Memory)  return true;

     }

   }

   return false;

 }

 #ifndef PRODUCT

 //------------------------------dump2------------------------------------------

 void Type::dump2( Dict &d, uint depth, outputStream *st ) const {

   st->print(msg[_base]);

 }

 //------------------------------dump-------------------------------------------

 void Type::dump_on(outputStream *st) const {

   ResourceMark rm;

   Dict d(cmpkey,hashkey);       // Stop recursive type dumping

   dump2(d,1, st);

   if (isa_ptr() && is_ptr()->is_narrow()) {

     st->print(" [narrow]");

   }

 }

 //------------------------------data-------------------------------------------

 const char * const Type::msg[Type::lastype] = {

   "bad","control","top","int:","long:","half", "narrowoop:",

   "tuple:", "aryptr",

   "anyptr:", "rawptr:", "java:", "inst:", "ary:", "klass:",

   "func", "abIO", "return_address", "memory",

   "float_top", "ftcon:", "float",

   "double_top", "dblcon:", "double",

   "bottom"

 };

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants (Ldi nodes).  Singletons are integer, float or double constants.

 bool Type::singleton(void) const {

   return _base == Top || _base == Half;

 }

 //------------------------------empty------------------------------------------

 // TRUE if Type is a type with no values, FALSE otherwise.

 bool Type::empty(void) const {

   switch (_base) {

   case DoubleTop:

   case FloatTop:

   case Top:

     return true;

   case Half:

   case Abio:

   case Return_Address:

   case Memory:

   case Bottom:

   case FloatBot:

   case DoubleBot:

     return false;  // never a singleton, therefore never empty

   }

   ShouldNotReachHere();

   return false;

 }

 //------------------------------dump_stats-------------------------------------

 // Dump collected statistics to stderr

 #ifndef PRODUCT

 void Type::dump_stats() {

   tty->print("Types made: %d\n", type_dict()->Size());

 }

 #endif

 //------------------------------typerr-----------------------------------------

 void Type::typerr( const Type *t ) const {

 #ifndef PRODUCT

   tty->print("\nError mixing types: ");

   dump();

   tty->print(" and ");

   t->dump();

   tty->print("\n");

 #endif

   ShouldNotReachHere();

 }

 //------------------------------isa_oop_ptr------------------------------------

 // Return true if type is an oop pointer type.  False for raw pointers.

 static char isa_oop_ptr_tbl[Type::lastype] = {

   0,0,0,0,0,0,0/*narrowoop*/,0/*tuple*/, 0/*ary*/,

   0/*anyptr*/,0/*rawptr*/,1/*OopPtr*/,1/*InstPtr*/,1/*AryPtr*/,1/*KlassPtr*/,

   0/*func*/,0,0/*return_address*/,0,

   /*floats*/0,0,0, /*doubles*/0,0,0,

   0

 };

 bool Type::isa_oop_ptr() const {

   return isa_oop_ptr_tbl[_base] != 0;

 }

 //------------------------------dump_stats-------------------------------------

 // // Check that arrays match type enum

 #ifndef PRODUCT

 void Type::verify_lastype() {

   // Check that arrays match enumeration

   assert( Type::dual_type  [Type::lastype - 1] == Type::Top, "did not update array");

   assert( strcmp(Type::msg [Type::lastype - 1],"bottom") == 0, "did not update array");

   // assert( PhiNode::tbl     [Type::lastype - 1] == NULL,    "did not update array");

   assert( Matcher::base2reg[Type::lastype - 1] == 0,      "did not update array");

   assert( isa_oop_ptr_tbl  [Type::lastype - 1] == (char)0,  "did not update array");

 }

 #endif

 //=============================================================================

 // Convenience common pre-built types.

 const TypeF *TypeF::ZERO;       // Floating point zero

 const TypeF *TypeF::ONE;        // Floating point one

 //------------------------------make-------------------------------------------

 // Create a float constant

 const TypeF *TypeF::make(float f) {

   return (TypeF*)(new TypeF(f))->hashcons();

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *TypeF::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Current "this->_base" is FloatCon

   switch (t->base()) {          // Switch on original type

   case AnyPtr:                  // Mixing with oops happens when javac

   case RawPtr:                  // reuses local variables

   case OopPtr:

   case InstPtr:

   case KlassPtr:

   case AryPtr:

   case Int:

   case Long:

   case DoubleTop:

   case DoubleCon:

   case DoubleBot:

   case Bottom:                  // Ye Olde Default

     return Type::BOTTOM;

   case FloatBot:

     return t;

   default:                      // All else is a mistake

     typerr(t);

   case FloatCon:                // Float-constant vs Float-constant?

     if( jint_cast(_f) != jint_cast(t->getf()) )         // unequal constants?

                                 // must compare bitwise as positive zero, negative zero and NaN have

                                 // all the same representation in C++

       return FLOAT;             // Return generic float

                                 // Equal constants

   case Top:

   case FloatTop:

     break;                      // Return the float constant

   }

   return this;                  // Return the float constant

 }

 //------------------------------xdual------------------------------------------

 // Dual: symmetric

 const Type *TypeF::xdual() const {

   return this;

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeF::eq( const Type *t ) const {

   if( g_isnan(_f) ||

       g_isnan(t->getf()) ) {

     // One or both are NANs.  If both are NANs return true, else false.

     return (g_isnan(_f) && g_isnan(t->getf()));

   }

   if (_f == t->getf()) {

     // (NaN is impossible at this point, since it is not equal even to itself)

     if (_f == 0.0) {

       // difference between positive and negative zero

       if (jint_cast(_f) != jint_cast(t->getf()))  return false;

     }

     return true;

   }

   return false;

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeF::hash(void) const {

   return *(int*)(&_f);

 }

 //------------------------------is_finite--------------------------------------

 // Has a finite value

 bool TypeF::is_finite() const {

   return g_isfinite(getf()) != 0;

 }

 //------------------------------is_nan-----------------------------------------

 // Is not a number (NaN)

 bool TypeF::is_nan()    const {

   return g_isnan(getf()) != 0;

 }

 //------------------------------dump2------------------------------------------

 // Dump float constant Type

 #ifndef PRODUCT

 void TypeF::dump2( Dict &d, uint depth, outputStream *st ) const {

   Type::dump2(d,depth, st);

   st->print("%f", _f);

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants (Ldi nodes).  Singletons are integer, float or double constants

 // or a single symbol.

 bool TypeF::singleton(void) const {

   return true;                  // Always a singleton

 }

 bool TypeF::empty(void) const {

   return false;                 // always exactly a singleton

 }

 //=============================================================================

 // Convenience common pre-built types.

 const TypeD *TypeD::ZERO;       // Floating point zero

 const TypeD *TypeD::ONE;        // Floating point one

 //------------------------------make-------------------------------------------

 const TypeD *TypeD::make(double d) {

   return (TypeD*)(new TypeD(d))->hashcons();

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *TypeD::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Current "this->_base" is DoubleCon

   switch (t->base()) {          // Switch on original type

   case AnyPtr:                  // Mixing with oops happens when javac

   case RawPtr:                  // reuses local variables

   case OopPtr:

   case InstPtr:

   case KlassPtr:

   case AryPtr:

   case Int:

   case Long:

   case FloatTop:

   case FloatCon:

   case FloatBot:

   case Bottom:                  // Ye Olde Default

     return Type::BOTTOM;

   case DoubleBot:

     return t;

   default:                      // All else is a mistake

     typerr(t);

   case DoubleCon:               // Double-constant vs Double-constant?

     if( jlong_cast(_d) != jlong_cast(t->getd()) )       // unequal constants? (see comment in TypeF::xmeet)

       return DOUBLE;            // Return generic double

   case Top:

   case DoubleTop:

     break;

   }

   return this;                  // Return the double constant

 }

 //------------------------------xdual------------------------------------------

 // Dual: symmetric

 const Type *TypeD::xdual() const {

   return this;

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeD::eq( const Type *t ) const {

   if( g_isnan(_d) ||

       g_isnan(t->getd()) ) {

     // One or both are NANs.  If both are NANs return true, else false.

     return (g_isnan(_d) && g_isnan(t->getd()));

   }

   if (_d == t->getd()) {

     // (NaN is impossible at this point, since it is not equal even to itself)

     if (_d == 0.0) {

       // difference between positive and negative zero

       if (jlong_cast(_d) != jlong_cast(t->getd()))  return false;

     }

     return true;

   }

   return false;

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeD::hash(void) const {

   return *(int*)(&_d);

 }

 //------------------------------is_finite--------------------------------------

 // Has a finite value

 bool TypeD::is_finite() const {

   return g_isfinite(getd()) != 0;

 }

 //------------------------------is_nan-----------------------------------------

 // Is not a number (NaN)

 bool TypeD::is_nan()    const {

   return g_isnan(getd()) != 0;

 }

 //------------------------------dump2------------------------------------------

 // Dump double constant Type

 #ifndef PRODUCT

 void TypeD::dump2( Dict &d, uint depth, outputStream *st ) const {

   Type::dump2(d,depth,st);

   st->print("%f", _d);

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants (Ldi nodes).  Singletons are integer, float or double constants

 // or a single symbol.

 bool TypeD::singleton(void) const {

   return true;                  // Always a singleton

 }

 bool TypeD::empty(void) const {

   return false;                 // always exactly a singleton

 }

 //=============================================================================

 // Convience common pre-built types.

 const TypeInt *TypeInt::MINUS_1;// -1

 const TypeInt *TypeInt::ZERO;   // 0

 const TypeInt *TypeInt::ONE;    // 1

 const TypeInt *TypeInt::BOOL;   // 0 or 1, FALSE or TRUE.

 const TypeInt *TypeInt::CC;     // -1,0 or 1, condition codes

 const TypeInt *TypeInt::CC_LT;  // [-1]  == MINUS_1

 const TypeInt *TypeInt::CC_GT;  // [1]   == ONE

 const TypeInt *TypeInt::CC_EQ;  // [0]   == ZERO

 const TypeInt *TypeInt::CC_LE;  // [-1,0]

 const TypeInt *TypeInt::CC_GE;  // [0,1] == BOOL (!)

 const TypeInt *TypeInt::BYTE;   // Bytes, -128 to 127

 const TypeInt *TypeInt::CHAR;   // Java chars, 0-65535

 const TypeInt *TypeInt::SHORT;  // Java shorts, -32768-32767

 const TypeInt *TypeInt::POS;    // Positive 32-bit integers or zero

 const TypeInt *TypeInt::POS1;   // Positive 32-bit integers

 const TypeInt *TypeInt::INT;    // 32-bit integers

 const TypeInt *TypeInt::SYMINT; // symmetric range [-max_jint..max_jint]

 //------------------------------TypeInt----------------------------------------

 TypeInt::TypeInt( jint lo, jint hi, int w ) : Type(Int), _lo(lo), _hi(hi), _widen(w) {

 }

 //------------------------------make-------------------------------------------

 const TypeInt *TypeInt::make( jint lo ) {

   return (TypeInt*)(new TypeInt(lo,lo,WidenMin))->hashcons();

 }

 #define SMALLINT ((juint)3)  // a value too insignificant to consider widening

 const TypeInt *TypeInt::make( jint lo, jint hi, int w ) {

   // Certain normalizations keep us sane when comparing types.

   // The 'SMALLINT' covers constants and also CC and its relatives.

   assert(CC == NULL || (juint)(CC->_hi - CC->_lo) <= SMALLINT, "CC is truly small");

   if (lo <= hi) {

     if ((juint)(hi - lo) <= SMALLINT)   w = Type::WidenMin;

     if ((juint)(hi - lo) >= max_juint)  w = Type::WidenMax; // plain int

   }

   return (TypeInt*)(new TypeInt(lo,hi,w))->hashcons();

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type representation object

 // with reference count equal to the number of Types pointing at it.

 // Caller should wrap a Types around it.

 const Type *TypeInt::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type?

   // Currently "this->_base" is a TypeInt

   switch (t->base()) {          // Switch on original type

   case AnyPtr:                  // Mixing with oops happens when javac

   case RawPtr:                  // reuses local variables

   case OopPtr:

   case InstPtr:

   case KlassPtr:

   case AryPtr:

   case Long:

   case FloatTop:

   case FloatCon:

   case FloatBot:

   case DoubleTop:

   case DoubleCon:

   case DoubleBot:

   case NarrowOop:

   case Bottom:                  // Ye Olde Default

     return Type::BOTTOM;

   default:                      // All else is a mistake

     typerr(t);

   case Top:                     // No change

     return this;

   case Int:                     // Int vs Int?

     break;

   }

   // Expand covered set

   const TypeInt *r = t->is_int();

   // (Avoid TypeInt::make, to avoid the argument normalizations it enforces.)

   return (new TypeInt( MIN2(_lo,r->_lo), MAX2(_hi,r->_hi), MAX2(_widen,r->_widen) ))->hashcons();

 }

 //------------------------------xdual------------------------------------------

 // Dual: reverse hi & lo; flip widen

 const Type *TypeInt::xdual() const {

   return new TypeInt(_hi,_lo,WidenMax-_widen);

 }

 //------------------------------widen------------------------------------------

 // Only happens for optimistic top-down optimizations.

 const Type *TypeInt::widen( const Type *old ) const {

   // Coming from TOP or such; no widening

   if( old->base() != Int ) return this;

   const TypeInt *ot = old->is_int();

   // If new guy is equal to old guy, no widening

   if( _lo == ot->_lo && _hi == ot->_hi )

     return old;

   // If new guy contains old, then we widened

   if( _lo <= ot->_lo && _hi >= ot->_hi ) {

     // New contains old

     // If new guy is already wider than old, no widening

     if( _widen > ot->_widen ) return this;

     // If old guy was a constant, do not bother

     if (ot->_lo == ot->_hi)  return this;

     // Now widen new guy.

     // Check for widening too far

     if (_widen == WidenMax) {

       if (min_jint < _lo && _hi < max_jint) {

         // If neither endpoint is extremal yet, push out the endpoint

         // which is closer to its respective limit.

         if (_lo >= 0 ||                 // easy common case

             (juint)(_lo - min_jint) >= (juint)(max_jint - _hi)) {

           // Try to widen to an unsigned range type of 31 bits:

           return make(_lo, max_jint, WidenMax);

         } else {

           return make(min_jint, _hi, WidenMax);

         }

       }

       return TypeInt::INT;

     }

     // Returned widened new guy

     return make(_lo,_hi,_widen+1);

   }

   // If old guy contains new, then we probably widened too far & dropped to

   // bottom.  Return the wider fellow.

   if ( ot->_lo <= _lo && ot->_hi >= _hi )

     return old;

   //fatal("Integer value range is not subset");

   //return this;

   return TypeInt::INT;

 }

 //------------------------------narrow---------------------------------------

 // Only happens for pessimistic optimizations.

 const Type *TypeInt::narrow( const Type *old ) const {

   if (_lo >= _hi)  return this;   // already narrow enough

   if (old == NULL)  return this;

   const TypeInt* ot = old->isa_int();

   if (ot == NULL)  return this;

   jint olo = ot->_lo;

   jint ohi = ot->_hi;

   // If new guy is equal to old guy, no narrowing

   if (_lo == olo && _hi == ohi)  return old;

   // If old guy was maximum range, allow the narrowing

   if (olo == min_jint && ohi == max_jint)  return this;

   if (_lo < olo || _hi > ohi)

     return this;                // doesn't narrow; pretty wierd

   // The new type narrows the old type, so look for a "death march".

   // See comments on PhaseTransform::saturate.

   juint nrange = _hi - _lo;

   juint orange = ohi - olo;

   if (nrange < max_juint - 1 && nrange > (orange >> 1) + (SMALLINT*2)) {

     // Use the new type only if the range shrinks a lot.

     // We do not want the optimizer computing 2^31 point by point.

     return old;

   }

   return this;

 }

 //-----------------------------filter------------------------------------------

 const Type *TypeInt::filter( const Type *kills ) const {

   const TypeInt* ft = join(kills)->isa_int();

   if (ft == NULL || ft->_lo > ft->_hi)

     return Type::TOP;           // Canonical empty value

   if (ft->_widen < this->_widen) {

     // Do not allow the value of kill->_widen to affect the outcome.

     // The widen bits must be allowed to run freely through the graph.

     ft = TypeInt::make(ft->_lo, ft->_hi, this->_widen);

   }

   return ft;

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeInt::eq( const Type *t ) const {

   const TypeInt *r = t->is_int(); // Handy access

   return r->_lo == _lo && r->_hi == _hi && r->_widen == _widen;

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeInt::hash(void) const {

   return _lo+_hi+_widen+(int)Type::Int;

 }

 //------------------------------is_finite--------------------------------------

 // Has a finite value

 bool TypeInt::is_finite() const {

   return true;

 }

 //------------------------------dump2------------------------------------------

 // Dump TypeInt

 #ifndef PRODUCT

 static const char* intname(char* buf, jint n) {

   if (n == min_jint)

     return "min";

   else if (n < min_jint + 10000)

     sprintf(buf, "min+" INT32_FORMAT, n - min_jint);

   else if (n == max_jint)

     return "max";

   else if (n > max_jint - 10000)

     sprintf(buf, "max-" INT32_FORMAT, max_jint - n);

   else

     sprintf(buf, INT32_FORMAT, n);

   return buf;

 }

 void TypeInt::dump2( Dict &d, uint depth, outputStream *st ) const {

   char buf[40], buf2[40];

   if (_lo == min_jint && _hi == max_jint)

     st->print("int");

   else if (is_con())

     st->print("int:%s", intname(buf, get_con()));

   else if (_lo == BOOL->_lo && _hi == BOOL->_hi)

     st->print("bool");

   else if (_lo == BYTE->_lo && _hi == BYTE->_hi)

     st->print("byte");

   else if (_lo == CHAR->_lo && _hi == CHAR->_hi)

     st->print("char");

   else if (_lo == SHORT->_lo && _hi == SHORT->_hi)

     st->print("short");

   else if (_hi == max_jint)

     st->print("int:>=%s", intname(buf, _lo));

   else if (_lo == min_jint)

     st->print("int:<=%s", intname(buf, _hi));

   else

     st->print("int:%s..%s", intname(buf, _lo), intname(buf2, _hi));

   if (_widen != 0 && this != TypeInt::INT)

     st->print(":%.*s", _widen, "wwww");

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants.

 bool TypeInt::singleton(void) const {

   return _lo >= _hi;

 }

 bool TypeInt::empty(void) const {

   return _lo > _hi;

 }

 //=============================================================================

 // Convenience common pre-built types.

 const TypeLong *TypeLong::MINUS_1;// -1

 const TypeLong *TypeLong::ZERO; // 0

 const TypeLong *TypeLong::ONE;  // 1

 const TypeLong *TypeLong::POS;  // >=0

 const TypeLong *TypeLong::LONG; // 64-bit integers

 const TypeLong *TypeLong::INT;  // 32-bit subrange

 const TypeLong *TypeLong::UINT; // 32-bit unsigned subrange

 //------------------------------TypeLong---------------------------------------

 TypeLong::TypeLong( jlong lo, jlong hi, int w ) : Type(Long), _lo(lo), _hi(hi), _widen(w) {

 }

 //------------------------------make-------------------------------------------

 const TypeLong *TypeLong::make( jlong lo ) {

   return (TypeLong*)(new TypeLong(lo,lo,WidenMin))->hashcons();

 }

 const TypeLong *TypeLong::make( jlong lo, jlong hi, int w ) {

   // Certain normalizations keep us sane when comparing types.

   // The '1' covers constants.

   if (lo <= hi) {

     if ((julong)(hi - lo) <= SMALLINT)    w = Type::WidenMin;

     if ((julong)(hi - lo) >= max_julong)  w = Type::WidenMax; // plain long

   }

   return (TypeLong*)(new TypeLong(lo,hi,w))->hashcons();

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type representation object

 // with reference count equal to the number of Types pointing at it.

 // Caller should wrap a Types around it.

 const Type *TypeLong::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type?

   // Currently "this->_base" is a TypeLong

   switch (t->base()) {          // Switch on original type

   case AnyPtr:                  // Mixing with oops happens when javac

   case RawPtr:                  // reuses local variables

   case OopPtr:

   case InstPtr:

   case KlassPtr:

   case AryPtr:

   case Int:

   case FloatTop:

   case FloatCon:

   case FloatBot:

   case DoubleTop:

   case DoubleCon:

   case DoubleBot:

   case Bottom:                  // Ye Olde Default

     return Type::BOTTOM;

   default:                      // All else is a mistake

     typerr(t);

   case Top:                     // No change

     return this;

   case Long:                    // Long vs Long?

     break;

   }

   // Expand covered set

   const TypeLong *r = t->is_long(); // Turn into a TypeLong

   // (Avoid TypeLong::make, to avoid the argument normalizations it enforces.)

   return (new TypeLong( MIN2(_lo,r->_lo), MAX2(_hi,r->_hi), MAX2(_widen,r->_widen) ))->hashcons();

 }

 //------------------------------xdual------------------------------------------

 // Dual: reverse hi & lo; flip widen

 const Type *TypeLong::xdual() const {

   return new TypeLong(_hi,_lo,WidenMax-_widen);

 }

 //------------------------------widen------------------------------------------

 // Only happens for optimistic top-down optimizations.

 const Type *TypeLong::widen( const Type *old ) const {

   // Coming from TOP or such; no widening

   if( old->base() != Long ) return this;

   const TypeLong *ot = old->is_long();

   // If new guy is equal to old guy, no widening

   if( _lo == ot->_lo && _hi == ot->_hi )

     return old;

   // If new guy contains old, then we widened

   if( _lo <= ot->_lo && _hi >= ot->_hi ) {

     // New contains old

     // If new guy is already wider than old, no widening

     if( _widen > ot->_widen ) return this;

     // If old guy was a constant, do not bother

     if (ot->_lo == ot->_hi)  return this;

     // Now widen new guy.

     // Check for widening too far

     if (_widen == WidenMax) {

       if (min_jlong < _lo && _hi < max_jlong) {

         // If neither endpoint is extremal yet, push out the endpoint

         // which is closer to its respective limit.

         if (_lo >= 0 ||                 // easy common case

             (julong)(_lo - min_jlong) >= (julong)(max_jlong - _hi)) {

           // Try to widen to an unsigned range type of 32/63 bits:

           if (_hi < max_juint)

             return make(_lo, max_juint, WidenMax);

           else

             return make(_lo, max_jlong, WidenMax);

         } else {

           return make(min_jlong, _hi, WidenMax);

         }

       }

       return TypeLong::LONG;

     }

     // Returned widened new guy

     return make(_lo,_hi,_widen+1);

   }

   // If old guy contains new, then we probably widened too far & dropped to

   // bottom.  Return the wider fellow.

   if ( ot->_lo <= _lo && ot->_hi >= _hi )

     return old;

   //  fatal("Long value range is not subset");

   // return this;

   return TypeLong::LONG;

 }

 //------------------------------narrow----------------------------------------

 // Only happens for pessimistic optimizations.

 const Type *TypeLong::narrow( const Type *old ) const {

   if (_lo >= _hi)  return this;   // already narrow enough

   if (old == NULL)  return this;

   const TypeLong* ot = old->isa_long();

   if (ot == NULL)  return this;

   jlong olo = ot->_lo;

   jlong ohi = ot->_hi;

   // If new guy is equal to old guy, no narrowing

   if (_lo == olo && _hi == ohi)  return old;

   // If old guy was maximum range, allow the narrowing

   if (olo == min_jlong && ohi == max_jlong)  return this;

   if (_lo < olo || _hi > ohi)

     return this;                // doesn't narrow; pretty wierd

   // The new type narrows the old type, so look for a "death march".

   // See comments on PhaseTransform::saturate.

   julong nrange = _hi - _lo;

   julong orange = ohi - olo;

   if (nrange < max_julong - 1 && nrange > (orange >> 1) + (SMALLINT*2)) {

     // Use the new type only if the range shrinks a lot.

     // We do not want the optimizer computing 2^31 point by point.

     return old;

   }

   return this;

 }

 //-----------------------------filter------------------------------------------

 const Type *TypeLong::filter( const Type *kills ) const {

   const TypeLong* ft = join(kills)->isa_long();

   if (ft == NULL || ft->_lo > ft->_hi)

     return Type::TOP;           // Canonical empty value

   if (ft->_widen < this->_widen) {

     // Do not allow the value of kill->_widen to affect the outcome.

     // The widen bits must be allowed to run freely through the graph.

     ft = TypeLong::make(ft->_lo, ft->_hi, this->_widen);

   }

   return ft;

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeLong::eq( const Type *t ) const {

   const TypeLong *r = t->is_long(); // Handy access

   return r->_lo == _lo &&  r->_hi == _hi  && r->_widen == _widen;

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeLong::hash(void) const {

   return (int)(_lo+_hi+_widen+(int)Type::Long);

 }

 //------------------------------is_finite--------------------------------------

 // Has a finite value

 bool TypeLong::is_finite() const {

   return true;

 }

 //------------------------------dump2------------------------------------------

 // Dump TypeLong

 #ifndef PRODUCT

 static const char* longnamenear(jlong x, const char* xname, char* buf, jlong n) {

   if (n > x) {

     if (n >= x + 10000)  return NULL;

     sprintf(buf, "%s+" INT64_FORMAT, xname, n - x);

   } else if (n < x) {

     if (n <= x - 10000)  return NULL;

     sprintf(buf, "%s-" INT64_FORMAT, xname, x - n);

   } else {

     return xname;

   }

   return buf;

 }

 static const char* longname(char* buf, jlong n) {

   const char* str;

   if (n == min_jlong)

     return "min";

   else if (n < min_jlong + 10000)

     sprintf(buf, "min+" INT64_FORMAT, n - min_jlong);

   else if (n == max_jlong)

     return "max";

   else if (n > max_jlong - 10000)

     sprintf(buf, "max-" INT64_FORMAT, max_jlong - n);

   else if ((str = longnamenear(max_juint, "maxuint", buf, n)) != NULL)

     return str;

   else if ((str = longnamenear(max_jint, "maxint", buf, n)) != NULL)

     return str;

   else if ((str = longnamenear(min_jint, "minint", buf, n)) != NULL)

     return str;

   else

     sprintf(buf, INT64_FORMAT, n);

   return buf;

 }

 void TypeLong::dump2( Dict &d, uint depth, outputStream *st ) const {

   char buf[80], buf2[80];

   if (_lo == min_jlong && _hi == max_jlong)

     st->print("long");

   else if (is_con())

     st->print("long:%s", longname(buf, get_con()));

   else if (_hi == max_jlong)

     st->print("long:>=%s", longname(buf, _lo));

   else if (_lo == min_jlong)

     st->print("long:<=%s", longname(buf, _hi));

   else

     st->print("long:%s..%s", longname(buf, _lo), longname(buf2, _hi));

   if (_widen != 0 && this != TypeLong::LONG)

     st->print(":%.*s", _widen, "wwww");

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants

 bool TypeLong::singleton(void) const {

   return _lo >= _hi;

 }

 bool TypeLong::empty(void) const {

   return _lo > _hi;

 }

 //=============================================================================

 // Convenience common pre-built types.

 const TypeTuple *TypeTuple::IFBOTH;     // Return both arms of IF as reachable

 const TypeTuple *TypeTuple::IFFALSE;

 const TypeTuple *TypeTuple::IFTRUE;

 const TypeTuple *TypeTuple::IFNEITHER;

 const TypeTuple *TypeTuple::LOOPBODY;

 const TypeTuple *TypeTuple::MEMBAR;

 const TypeTuple *TypeTuple::STORECONDITIONAL;

 const TypeTuple *TypeTuple::START_I2C;

 const TypeTuple *TypeTuple::INT_PAIR;

 const TypeTuple *TypeTuple::LONG_PAIR;

 //------------------------------make-------------------------------------------

 // Make a TypeTuple from the range of a method signature

 const TypeTuple *TypeTuple::make_range(ciSignature* sig) {

   ciType* return_type = sig->return_type();

   uint total_fields = TypeFunc::Parms + return_type->size();

   const Type **field_array = fields(total_fields);

   switch (return_type->basic_type()) {

   case T_LONG:

     field_array[TypeFunc::Parms]   = TypeLong::LONG;

     field_array[TypeFunc::Parms+1] = Type::HALF;

     break;

   case T_DOUBLE:

     field_array[TypeFunc::Parms]   = Type::DOUBLE;

     field_array[TypeFunc::Parms+1] = Type::HALF;

     break;

   case T_OBJECT:

   case T_ARRAY:

   case T_BOOLEAN:

   case T_CHAR:

   case T_FLOAT:

   case T_BYTE:

   case T_SHORT:

   case T_INT:

     field_array[TypeFunc::Parms] = get_const_type(return_type);

     break;

   case T_VOID:

     break;

   default:

     ShouldNotReachHere();

   }

   return (TypeTuple*)(new TypeTuple(total_fields,field_array))->hashcons();

 }

 // Make a TypeTuple from the domain of a method signature

 const TypeTuple *TypeTuple::make_domain(ciInstanceKlass* recv, ciSignature* sig) {

   uint total_fields = TypeFunc::Parms + sig->size();

   uint pos = TypeFunc::Parms;

   const Type **field_array;

   if (recv != NULL) {

     total_fields++;

     field_array = fields(total_fields);

     // Use get_const_type here because it respects UseUniqueSubclasses:

     field_array[pos++] = get_const_type(recv)->join(TypePtr::NOTNULL);

   } else {

     field_array = fields(total_fields);

   }

   int i = 0;

   while (pos < total_fields) {

     ciType* type = sig->type_at(i);

     switch (type->basic_type()) {

     case T_LONG:

       field_array[pos++] = TypeLong::LONG;

       field_array[pos++] = Type::HALF;

       break;

     case T_DOUBLE:

       field_array[pos++] = Type::DOUBLE;

       field_array[pos++] = Type::HALF;

       break;

     case T_OBJECT:

     case T_ARRAY:

     case T_BOOLEAN:

     case T_CHAR:

     case T_FLOAT:

     case T_BYTE:

     case T_SHORT:

     case T_INT:

       field_array[pos++] = get_const_type(type);

       break;

     default:

       ShouldNotReachHere();

     }

     i++;

   }

   return (TypeTuple*)(new TypeTuple(total_fields,field_array))->hashcons();

 }

 const TypeTuple *TypeTuple::make( uint cnt, const Type **fields ) {

   return (TypeTuple*)(new TypeTuple(cnt,fields))->hashcons();

 }

 //------------------------------fields-----------------------------------------

 // Subroutine call type with space allocated for argument types

 const Type **TypeTuple::fields( uint arg_cnt ) {

   const Type **flds = (const Type **)(Compile::current()->type_arena()->Amalloc_4((TypeFunc::Parms+arg_cnt)*sizeof(Type*) ));

   flds[TypeFunc::Control  ] = Type::CONTROL;

   flds[TypeFunc::I_O      ] = Type::ABIO;

   flds[TypeFunc::Memory   ] = Type::MEMORY;

   flds[TypeFunc::FramePtr ] = TypeRawPtr::BOTTOM;

   flds[TypeFunc::ReturnAdr] = Type::RETURN_ADDRESS;

   return flds;

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *TypeTuple::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Current "this->_base" is Tuple

   switch (t->base()) {          // switch on original type

   case Bottom:                  // Ye Olde Default

     return t;

   default:                      // All else is a mistake

     typerr(t);

   case Tuple: {                 // Meeting 2 signatures?

     const TypeTuple *x = t->is_tuple();

     assert( _cnt == x->_cnt, "" );

     const Type **fields = (const Type **)(Compile::current()->type_arena()->Amalloc_4( _cnt*sizeof(Type*) ));

     for( uint i=0; i<_cnt; i++ )

       fields[i] = field_at(i)->xmeet( x->field_at(i) );

     return TypeTuple::make(_cnt,fields);

   }

   case Top:

     break;

   }

   return this;                  // Return the double constant

 }

 //------------------------------xdual------------------------------------------

 // Dual: compute field-by-field dual

 const Type *TypeTuple::xdual() const {

   const Type **fields = (const Type **)(Compile::current()->type_arena()->Amalloc_4( _cnt*sizeof(Type*) ));

   for( uint i=0; i<_cnt; i++ )

     fields[i] = _fields[i]->dual();

   return new TypeTuple(_cnt,fields);

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeTuple::eq( const Type *t ) const {

   const TypeTuple *s = (const TypeTuple *)t;

   if (_cnt != s->_cnt)  return false;  // Unequal field counts

   for (uint i = 0; i < _cnt; i++)

     if (field_at(i) != s->field_at(i)) // POINTER COMPARE!  NO RECURSION!

       return false;             // Missed

   return true;

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeTuple::hash(void) const {

   intptr_t sum = _cnt;

   for( uint i=0; i<_cnt; i++ )

     sum += (intptr_t)_fields[i];     // Hash on pointers directly

   return sum;

 }

 //------------------------------dump2------------------------------------------

 // Dump signature Type

 #ifndef PRODUCT

 void TypeTuple::dump2( Dict &d, uint depth, outputStream *st ) const {

   st->print("{");

   if( !depth || d[this] ) {     // Check for recursive print

     st->print("...}");

     return;

   }

   d.Insert((void*)this, (void*)this);   // Stop recursion

   if( _cnt ) {

     uint i;

     for( i=0; i<_cnt-1; i++ ) {

       st->print("%d:", i);

       _fields[i]->dump2(d, depth-1, st);

       st->print(", ");

     }

     st->print("%d:", i);

     _fields[i]->dump2(d, depth-1, st);

   }

   st->print("}");

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants (Ldi nodes).  Singletons are integer, float or double constants

 // or a single symbol.

 bool TypeTuple::singleton(void) const {

   return false;                 // Never a singleton

 }

 bool TypeTuple::empty(void) const {

   for( uint i=0; i<_cnt; i++ ) {

     if (_fields[i]->empty())  return true;

   }

   return false;

 }

 //=============================================================================

 // Convenience common pre-built types.

 inline const TypeInt* normalize_array_size(const TypeInt* size) {

   // Certain normalizations keep us sane when comparing types.

   // We do not want arrayOop variables to differ only by the wideness

   // of their index types.  Pick minimum wideness, since that is the

   // forced wideness of small ranges anyway.

   if (size->_widen != Type::WidenMin)

     return TypeInt::make(size->_lo, size->_hi, Type::WidenMin);

   else

     return size;

 }

 //------------------------------make-------------------------------------------

 const TypeAry *TypeAry::make( const Type *elem, const TypeInt *size) {

   if (UseCompressedOops && elem->isa_oopptr()) {

     elem = elem->is_oopptr()->make_narrowoop();

   }

   size = normalize_array_size(size);

   return (TypeAry*)(new TypeAry(elem,size))->hashcons();

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *TypeAry::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Current "this->_base" is Ary

   switch (t->base()) {          // switch on original type

   case Bottom:                  // Ye Olde Default

     return t;

   default:                      // All else is a mistake

     typerr(t);

   case Array: {                 // Meeting 2 arrays?

     const TypeAry *a = t->is_ary();

     return TypeAry::make(_elem->meet(a->_elem),

                          _size->xmeet(a->_size)->is_int());

   }

   case Top:

     break;

   }

   return this;                  // Return the double constant

 }

 //------------------------------xdual------------------------------------------

 // Dual: compute field-by-field dual

 const Type *TypeAry::xdual() const {

   const TypeInt* size_dual = _size->dual()->is_int();

   size_dual = normalize_array_size(size_dual);

   return new TypeAry( _elem->dual(), size_dual);

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeAry::eq( const Type *t ) const {

   const TypeAry *a = (const TypeAry*)t;

   return _elem == a->_elem &&

     _size == a->_size;

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeAry::hash(void) const {

   return (intptr_t)_elem + (intptr_t)_size;

 }

 //------------------------------dump2------------------------------------------

 #ifndef PRODUCT

 void TypeAry::dump2( Dict &d, uint depth, outputStream *st ) const {

   _elem->dump2(d, depth, st);

   st->print("[");

   _size->dump2(d, depth, st);

   st->print("]");

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants (Ldi nodes).  Singletons are integer, float or double constants

 // or a single symbol.

 bool TypeAry::singleton(void) const {

   return false;                 // Never a singleton

 }

 bool TypeAry::empty(void) const {

   return _elem->empty() || _size->empty();

 }

 //--------------------------ary_must_be_exact----------------------------------

 bool TypeAry::ary_must_be_exact() const {

   if (!UseExactTypes)       return false;

   // This logic looks at the element type of an array, and returns true

   // if the element type is either a primitive or a final instance class.

   // In such cases, an array built on this ary must have no subclasses.

   if (_elem == BOTTOM)      return false;  // general array not exact

   if (_elem == TOP   )      return false;  // inverted general array not exact

   const TypeOopPtr*  toop = NULL;

   if (UseCompressedOops) {

     const TypeNarrowOop* noop = _elem->isa_narrowoop();

     if (noop) toop = noop->make_oopptr()->isa_oopptr();

   } else {

     toop = _elem->isa_oopptr();

   }

   if (!toop)                return true;   // a primitive type, like int

   ciKlass* tklass = toop->klass();

   if (tklass == NULL)       return false;  // unloaded class

   if (!tklass->is_loaded()) return false;  // unloaded class

   const TypeInstPtr* tinst;

   if (_elem->isa_narrowoop())

     tinst = _elem->is_narrowoop()->make_oopptr()->isa_instptr();

   else

     tinst = _elem->isa_instptr();

   if (tinst)                return tklass->as_instance_klass()->is_final();

   const TypeAryPtr*  tap;

   if (_elem->isa_narrowoop())

     tap = _elem->is_narrowoop()->make_oopptr()->isa_aryptr();

   else

     tap = _elem->isa_aryptr();

   if (tap)                  return tap->ary()->ary_must_be_exact();

   return false;

 }

 //=============================================================================

 // Convenience common pre-built types.

 const TypePtr *TypePtr::NULL_PTR;

 const TypePtr *TypePtr::NOTNULL;

 const TypePtr *TypePtr::BOTTOM;

 //------------------------------meet-------------------------------------------

 // Meet over the PTR enum

 const TypePtr::PTR TypePtr::ptr_meet[TypePtr::lastPTR][TypePtr::lastPTR] = {

   //              TopPTR,    AnyNull,   Constant, Null,   NotNull, BotPTR,

   { /* Top     */ TopPTR,    AnyNull,   Constant, Null,   NotNull, BotPTR,},

   { /* AnyNull */ AnyNull,   AnyNull,   Constant, BotPTR, NotNull, BotPTR,},

   { /* Constant*/ Constant,  Constant,  Constant, BotPTR, NotNull, BotPTR,},

   { /* Null    */ Null,      BotPTR,    BotPTR,   Null,   BotPTR,  BotPTR,},

   { /* NotNull */ NotNull,   NotNull,   NotNull,  BotPTR, NotNull, BotPTR,},

   { /* BotPTR  */ BotPTR,    BotPTR,    BotPTR,   BotPTR, BotPTR,  BotPTR,}

 };

 //------------------------------make-------------------------------------------

 const TypePtr *TypePtr::make( TYPES t, enum PTR ptr, int offset ) {

   return (TypePtr*)(new TypePtr(t,ptr,offset))->hashcons();

 }

 //------------------------------cast_to_ptr_type-------------------------------

 const Type *TypePtr::cast_to_ptr_type(PTR ptr) const {

   assert(_base == AnyPtr, "subclass must override cast_to_ptr_type");

   if( ptr == _ptr ) return this;

   return make(_base, ptr, _offset);

 }

 //------------------------------get_con----------------------------------------

 intptr_t TypePtr::get_con() const {

   assert( _ptr == Null, "" );

   return _offset;

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *TypePtr::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Current "this->_base" is AnyPtr

   switch (t->base()) {          // switch on original type

   case Int:                     // Mixing ints & oops happens when javac

   case Long:                    // reuses local variables

   case FloatTop:

   case FloatCon:

   case FloatBot:

   case DoubleTop:

   case DoubleCon:

   case DoubleBot:

   case NarrowOop:

   case Bottom:                  // Ye Olde Default

     return Type::BOTTOM;

   case Top:

     return this;

   case AnyPtr: {                // Meeting to AnyPtrs

     const TypePtr *tp = t->is_ptr();

     return make( AnyPtr, meet_ptr(tp->ptr()), meet_offset(tp->offset()) );

   }

   case RawPtr:                  // For these, flip the call around to cut down

   case OopPtr:

   case InstPtr:                 // on the cases I have to handle.

   case KlassPtr:

   case AryPtr:

     return t->xmeet(this);      // Call in reverse direction

   default:                      // All else is a mistake

     typerr(t);

   }

   return this;

 }

 //------------------------------meet_offset------------------------------------

 int TypePtr::meet_offset( int offset ) const {

   // Either is 'TOP' offset?  Return the other offset!

   if( _offset == OffsetTop ) return offset;

   if( offset == OffsetTop ) return _offset;

   // If either is different, return 'BOTTOM' offset

   if( _offset != offset ) return OffsetBot;

   return _offset;

 }

 //------------------------------dual_offset------------------------------------

 int TypePtr::dual_offset( ) const {

   if( _offset == OffsetTop ) return OffsetBot;// Map 'TOP' into 'BOTTOM'

   if( _offset == OffsetBot ) return OffsetTop;// Map 'BOTTOM' into 'TOP'

   return _offset;               // Map everything else into self

 }

 //------------------------------xdual------------------------------------------

 // Dual: compute field-by-field dual

 const TypePtr::PTR TypePtr::ptr_dual[TypePtr::lastPTR] = {

   BotPTR, NotNull, Constant, Null, AnyNull, TopPTR

 };

 const Type *TypePtr::xdual() const {

   return new TypePtr( AnyPtr, dual_ptr(), dual_offset() );

 }

 //------------------------------add_offset-------------------------------------

 const TypePtr *TypePtr::add_offset( int offset ) const {

   if( offset == 0 ) return this; // No change

   if( _offset == OffsetBot ) return this;

   if(  offset == OffsetBot ) offset = OffsetBot;

   else if( _offset == OffsetTop || offset == OffsetTop ) offset = OffsetTop;

   else offset += _offset;

   return make( AnyPtr, _ptr, offset );

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypePtr::eq( const Type *t ) const {

   const TypePtr *a = (const TypePtr*)t;

   return _ptr == a->ptr() && _offset == a->offset();

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypePtr::hash(void) const {

   return _ptr + _offset;

 }

 //------------------------------dump2------------------------------------------

 const char *const TypePtr::ptr_msg[TypePtr::lastPTR] = {

   "TopPTR","AnyNull","Constant","NULL","NotNull","BotPTR"

 };

 #ifndef PRODUCT

 void TypePtr::dump2( Dict &d, uint depth, outputStream *st ) const {

   if( _ptr == Null ) st->print("NULL");

   else st->print("%s *", ptr_msg[_ptr]);

   if( _offset == OffsetTop ) st->print("+top");

   else if( _offset == OffsetBot ) st->print("+bot");

   else if( _offset ) st->print("+%d", _offset);

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants

 bool TypePtr::singleton(void) const {

   // TopPTR, Null, AnyNull, Constant are all singletons

   return (_offset != OffsetBot) && !below_centerline(_ptr);

 }

 bool TypePtr::empty(void) const {

   return (_offset == OffsetTop) || above_centerline(_ptr);

 }

 //=============================================================================

 // Convenience common pre-built types.

 const TypeRawPtr *TypeRawPtr::BOTTOM;

 const TypeRawPtr *TypeRawPtr::NOTNULL;

 //------------------------------make-------------------------------------------

 const TypeRawPtr *TypeRawPtr::make( enum PTR ptr ) {

   assert( ptr != Constant, "what is the constant?" );

   assert( ptr != Null, "Use TypePtr for NULL" );

   return (TypeRawPtr*)(new TypeRawPtr(ptr,0))->hashcons();

 }

 const TypeRawPtr *TypeRawPtr::make( address bits ) {

   assert( bits, "Use TypePtr for NULL" );

   return (TypeRawPtr*)(new TypeRawPtr(Constant,bits))->hashcons();

 }

 //------------------------------cast_to_ptr_type-------------------------------

 const Type *TypeRawPtr::cast_to_ptr_type(PTR ptr) const {

   assert( ptr != Constant, "what is the constant?" );

   assert( ptr != Null, "Use TypePtr for NULL" );

   assert( _bits==0, "Why cast a constant address?");

   if( ptr == _ptr ) return this;

   return make(ptr);

 }

 //------------------------------get_con----------------------------------------

 intptr_t TypeRawPtr::get_con() const {

   assert( _ptr == Null || _ptr == Constant, "" );

   return (intptr_t)_bits;

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *TypeRawPtr::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Current "this->_base" is RawPtr

   switch( t->base() ) {         // switch on original type

   case Bottom:                  // Ye Olde Default

     return t;

   case Top:

     return this;

   case AnyPtr:                  // Meeting to AnyPtrs

     break;

   case RawPtr: {                // might be top, bot, any/not or constant

     enum PTR tptr = t->is_ptr()->ptr();

     enum PTR ptr = meet_ptr( tptr );

     if( ptr == Constant ) {     // Cannot be equal constants, so...

       if( tptr == Constant && _ptr != Constant)  return t;

       if( _ptr == Constant && tptr != Constant)  return this;

       ptr = NotNull;            // Fall down in lattice

     }

     return make( ptr );

   }

   case OopPtr:

   case InstPtr:

   case KlassPtr:

   case AryPtr:

     return TypePtr::BOTTOM;     // Oop meet raw is not well defined

   default:                      // All else is a mistake

     typerr(t);

   }

   // Found an AnyPtr type vs self-RawPtr type

   const TypePtr *tp = t->is_ptr();

   switch (tp->ptr()) {

   case TypePtr::TopPTR:  return this;

   case TypePtr::BotPTR:  return t;

   case TypePtr::Null:

     if( _ptr == TypePtr::TopPTR ) return t;

     return TypeRawPtr::BOTTOM;

   case TypePtr::NotNull: return TypePtr::make( AnyPtr, meet_ptr(TypePtr::NotNull), tp->meet_offset(0) );

   case TypePtr::AnyNull:

     if( _ptr == TypePtr::Constant) return this;

     return make( meet_ptr(TypePtr::AnyNull) );

   default: ShouldNotReachHere();

   }

   return this;

 }

 //------------------------------xdual------------------------------------------

 // Dual: compute field-by-field dual

 const Type *TypeRawPtr::xdual() const {

   return new TypeRawPtr( dual_ptr(), _bits );

 }

 //------------------------------add_offset-------------------------------------

 const TypePtr *TypeRawPtr::add_offset( int offset ) const {

   if( offset == OffsetTop ) return BOTTOM; // Undefined offset-> undefined pointer

   if( offset == OffsetBot ) return BOTTOM; // Unknown offset-> unknown pointer

   if( offset == 0 ) return this; // No change

   switch (_ptr) {

   case TypePtr::TopPTR:

   case TypePtr::BotPTR:

   case TypePtr::NotNull:

     return this;

   case TypePtr::Null:

   case TypePtr::Constant:

     return make( _bits+offset );

   default:  ShouldNotReachHere();

   }

   return NULL;                  // Lint noise

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeRawPtr::eq( const Type *t ) const {

   const TypeRawPtr *a = (const TypeRawPtr*)t;

   return _bits == a->_bits && TypePtr::eq(t);

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeRawPtr::hash(void) const {

   return (intptr_t)_bits + TypePtr::hash();

 }

 //------------------------------dump2------------------------------------------

 #ifndef PRODUCT

 void TypeRawPtr::dump2( Dict &d, uint depth, outputStream *st ) const {

   if( _ptr == Constant )

     st->print(INTPTR_FORMAT, _bits);

   else

     st->print("rawptr:%s", ptr_msg[_ptr]);

 }

 #endif

 //=============================================================================

 // Convenience common pre-built type.

 const TypeOopPtr *TypeOopPtr::BOTTOM;

 //------------------------------make-------------------------------------------

 const TypeOopPtr *TypeOopPtr::make(PTR ptr,

                                    int offset) {

   assert(ptr != Constant, "no constant generic pointers");

   ciKlass*  k = ciKlassKlass::make();

   bool      xk = false;

   ciObject* o = NULL;

   return (TypeOopPtr*)(new TypeOopPtr(OopPtr, ptr, k, xk, o, offset, UNKNOWN_INSTANCE))->hashcons();

 }

 //------------------------------cast_to_ptr_type-------------------------------

 const Type *TypeOopPtr::cast_to_ptr_type(PTR ptr) const {

   assert(_base == OopPtr, "subclass must override cast_to_ptr_type");

   if( ptr == _ptr ) return this;

   return make(ptr, _offset);

 }

 //-----------------------------cast_to_instance-------------------------------

 const TypeOopPtr *TypeOopPtr::cast_to_instance(int instance_id) const {

   // There are no instances of a general oop.

   // Return self unchanged.

   return this;

 }

 //-----------------------------cast_to_exactness-------------------------------

 const Type *TypeOopPtr::cast_to_exactness(bool klass_is_exact) const {

   // There is no such thing as an exact general oop.

   // Return self unchanged.

   return this;

 }

 //------------------------------as_klass_type----------------------------------

 // Return the klass type corresponding to this instance or array type.

 // It is the type that is loaded from an object of this type.

 const TypeKlassPtr* TypeOopPtr::as_klass_type() const {

   ciKlass* k = klass();

   bool    xk = klass_is_exact();

   if (k == NULL || !k->is_java_klass())

     return TypeKlassPtr::OBJECT;

   else

     return TypeKlassPtr::make(xk? Constant: NotNull, k, 0);

 }

 //------------------------------meet-------------------------------------------

 // Compute the MEET of two types.  It returns a new Type object.

 const Type *TypeOopPtr::xmeet( const Type *t ) const {

   // Perform a fast test for common case; meeting the same types together.

   if( this == t ) return this;  // Meeting same type-rep?

   // Current "this->_base" is OopPtr

   switch (t->base()) {          // switch on original type

   case Int:                     // Mixing ints & oops happens when javac

   case Long:                    // reuses local variables

   case FloatTop:

   case FloatCon:

   case FloatBot:

   case DoubleTop:

   case DoubleCon:

   case DoubleBot:

   case Bottom:                  // Ye Olde Default

     return Type::BOTTOM;

   case Top:

     return this;

   default:                      // All else is a mistake

     typerr(t);

   case RawPtr:

     return TypePtr::BOTTOM;     // Oop meet raw is not well defined

   case AnyPtr: {

     // Found an AnyPtr type vs self-OopPtr type

     const TypePtr *tp = t->is_ptr();

     int offset = meet_offset(tp->offset());

     PTR ptr = meet_ptr(tp->ptr());

     switch (tp->ptr()) {

     case Null:

       if (ptr == Null)  return TypePtr::make(AnyPtr, ptr, offset);

       // else fall through:

     case TopPTR:

     case AnyNull:

       return make(ptr, offset);

     case BotPTR:

     case NotNull:

       return TypePtr::make(AnyPtr, ptr, offset);

     default: typerr(t);

     }

   }

   case OopPtr: {                 // Meeting to other OopPtrs

     const TypeOopPtr *tp = t->is_oopptr();

     return make( meet_ptr(tp->ptr()), meet_offset(tp->offset()) );

   }

   case InstPtr:                  // For these, flip the call around to cut down

   case KlassPtr:                 // on the cases I have to handle.

   case AryPtr:

     return t->xmeet(this);      // Call in reverse direction

   } // End of switch

   return this;                  // Return the double constant

 }

 //------------------------------xdual------------------------------------------

 // Dual of a pure heap pointer.  No relevant klass or oop information.

 const Type *TypeOopPtr::xdual() const {

   assert(klass() == ciKlassKlass::make(), "no klasses here");

   assert(const_oop() == NULL,             "no constants here");

   return new TypeOopPtr(_base, dual_ptr(), klass(), klass_is_exact(), const_oop(), dual_offset(), dual_instance()  );

 }

 //--------------------------make_from_klass_common-----------------------------

 // Computes the element-type given a klass.

 const TypeOopPtr* TypeOopPtr::make_from_klass_common(ciKlass *klass, bool klass_change, bool try_for_exact) {

   assert(klass->is_java_klass(), "must be java language klass");

   if (klass->is_instance_klass()) {

     Compile* C = Compile::current();

     Dependencies* deps = C->dependencies();

     assert((deps != NULL) == (C->method() != NULL && C->method()->code_size() > 0), "sanity");

     // Element is an instance

     bool klass_is_exact = false;

     if (klass->is_loaded()) {

       // Try to set klass_is_exact.

       ciInstanceKlass* ik = klass->as_instance_klass();

       klass_is_exact = ik->is_final();

       if (!klass_is_exact && klass_change

           && deps != NULL && UseUniqueSubclasses) {

         ciInstanceKlass* sub = ik->unique_concrete_subklass();

         if (sub != NULL) {

           deps->assert_abstract_with_unique_concrete_subtype(ik, sub);

           klass = ik = sub;

           klass_is_exact = sub->is_final();

         }

       }

       if (!klass_is_exact && try_for_exact

           && deps != NULL && UseExactTypes) {

         if (!ik->is_interface() && !ik->has_subklass()) {

           // Add a dependence; if concrete subclass added we need to recompile

           deps->assert_leaf_type(ik);

           klass_is_exact = true;

         }

       }

     }

     return TypeInstPtr::make(TypePtr::BotPTR, klass, klass_is_exact, NULL, 0);

   } else if (klass->is_obj_array_klass()) {

     // Element is an object array. Recursively call ourself.

     const TypeOopPtr *etype = TypeOopPtr::make_from_klass_common(klass->as_obj_array_klass()->element_klass(), false, try_for_exact);

     bool xk = etype->klass_is_exact();

     const TypeAry* arr0 = TypeAry::make(etype, TypeInt::POS);

     // We used to pass NotNull in here, asserting that the sub-arrays

     // are all not-null.  This is not true in generally, as code can

     // slam NULLs down in the subarrays.

     const TypeAryPtr* arr = TypeAryPtr::make(TypePtr::BotPTR, arr0, klass, xk, 0);

     return arr;

   } else if (klass->is_type_array_klass()) {

     // Element is an typeArray

     const Type* etype = get_const_basic_type(klass->as_type_array_klass()->element_type());

     const TypeAry* arr0 = TypeAry::make(etype, TypeInt::POS);

     // We used to pass NotNull in here, asserting that the array pointer

     // is not-null. That was not true in general.

     const TypeAryPtr* arr = TypeAryPtr::make(TypePtr::BotPTR, arr0, klass, true, 0);

     return arr;

   } else {

     ShouldNotReachHere();

     return NULL;

   }

 }

 //------------------------------make_from_constant-----------------------------

 // Make a java pointer from an oop constant

 const TypeOopPtr* TypeOopPtr::make_from_constant(ciObject* o) {

   if (o->is_method_data() || o->is_method()) {

     // Treat much like a typeArray of bytes, like below, but fake the type...

     assert(o->has_encoding(), "must be a perm space object");

     const Type* etype = (Type*)get_const_basic_type(T_BYTE);

     const TypeAry* arr0 = TypeAry::make(etype, TypeInt::POS);

     ciKlass *klass = ciTypeArrayKlass::make((BasicType) T_BYTE);

     assert(o->has_encoding(), "method data oops should be tenured");

     const TypeAryPtr* arr = TypeAryPtr::make(TypePtr::Constant, o, arr0, klass, true, 0);

     return arr;

   } else {

     assert(o->is_java_object(), "must be java language object");

     assert(!o->is_null_object(), "null object not yet handled here.");

     ciKlass *klass = o->klass();

     if (klass->is_instance_klass()) {

       // Element is an instance

       if (!o->has_encoding()) {  // not a perm-space constant

         // %%% remove this restriction by rewriting non-perm ConPNodes in a later phase

         return TypeInstPtr::make(TypePtr::NotNull, klass, true, NULL, 0);

       }

       return TypeInstPtr::make(o);

     } else if (klass->is_obj_array_klass()) {

       // Element is an object array. Recursively call ourself.

       const Type *etype =

         TypeOopPtr::make_from_klass_raw(klass->as_obj_array_klass()->element_klass());

       const TypeAry* arr0 = TypeAry::make(etype, TypeInt::make(o->as_array()->length()));

       // We used to pass NotNull in here, asserting that the sub-arrays

       // are all not-null.  This is not true in generally, as code can

       // slam NULLs down in the subarrays.

       if (!o->has_encoding()) {  // not a perm-space constant

         // %%% remove this restriction by rewriting non-perm ConPNodes in a later phase

         return TypeAryPtr::make(TypePtr::NotNull, arr0, klass, true, 0);

       }

       const TypeAryPtr* arr = TypeAryPtr::make(TypePtr::Constant, o, arr0, klass, true, 0);

       return arr;

     } else if (klass->is_type_array_klass()) {

       // Element is an typeArray

       const Type* etype =

         (Type*)get_const_basic_type(klass->as_type_array_klass()->element_type());

       const TypeAry* arr0 = TypeAry::make(etype, TypeInt::make(o->as_array()->length()));

       // We used to pass NotNull in here, asserting that the array pointer

       // is not-null. That was not true in general.

       if (!o->has_encoding()) {  // not a perm-space constant

         // %%% remove this restriction by rewriting non-perm ConPNodes in a later phase

         return TypeAryPtr::make(TypePtr::NotNull, arr0, klass, true, 0);

       }

       const TypeAryPtr* arr = TypeAryPtr::make(TypePtr::Constant, o, arr0, klass, true, 0);

       return arr;

     }

   }

   ShouldNotReachHere();

   return NULL;

 }

 //------------------------------get_con----------------------------------------

 intptr_t TypeOopPtr::get_con() const {

   assert( _ptr == Null || _ptr == Constant, "" );

   assert( _offset >= 0, "" );

   if (_offset != 0) {

     // After being ported to the compiler interface, the compiler no longer

     // directly manipulates the addresses of oops.  Rather, it only has a pointer

     // to a handle at compile time.  This handle is embedded in the generated

     // code and dereferenced at the time the nmethod is made.  Until that time,

     // it is not reasonable to do arithmetic with the addresses of oops (we don't

     // have access to the addresses!).  This does not seem to currently happen,

     // but this assertion here is to help prevent its occurrance.

     tty->print_cr("Found oop constant with non-zero offset");

     ShouldNotReachHere();

   }

   return (intptr_t)const_oop()->encoding();

 }

 //-----------------------------filter------------------------------------------

 // Do not allow interface-vs.-noninterface joins to collapse to top.

 const Type *TypeOopPtr::filter( const Type *kills ) const {

   const Type* ft = join(kills);

   const TypeInstPtr* ftip = ft->isa_instptr();

   const TypeInstPtr* ktip = kills->isa_instptr();

   if (ft->empty()) {

     // Check for evil case of 'this' being a class and 'kills' expecting an

     // interface.  This can happen because the bytecodes do not contain

     // enough type info to distinguish a Java-level interface variable

     // from a Java-level object variable.  If we meet 2 classes which

     // both implement interface I, but their meet is at 'j/l/O' which

     // doesn't implement I, we have no way to tell if the result should

     // be 'I' or 'j/l/O'.  Thus we'll pick 'j/l/O'.  If this then flows

     // into a Phi which "knows" it's an Interface type we'll have to

     // uplift the type.

     if (!empty() && ktip != NULL && ktip->is_loaded() && ktip->klass()->is_interface())

       return kills;             // Uplift to interface

     return Type::TOP;           // Canonical empty value

   }

   // If we have an interface-typed Phi or cast and we narrow to a class type,

   // the join should report back the class.  However, if we have a J/L/Object

   // class-typed Phi and an interface flows in, it's possible that the meet &

   // join report an interface back out.  This isn't possible but happens

   // because the type system doesn't interact well with interfaces.

   if (ftip != NULL && ktip != NULL &&

       ftip->is_loaded() &&  ftip->klass()->is_interface() &&

       ktip->is_loaded() && !ktip->klass()->is_interface()) {

     // Happens in a CTW of rt.jar, 320-341, no extra flags

     return ktip->cast_to_ptr_type(ftip->ptr());

   }

   return ft;

 }

 //------------------------------eq---------------------------------------------

 // Structural equality check for Type representations

 bool TypeOopPtr::eq( const Type *t ) const {

   const TypeOopPtr *a = (const TypeOopPtr*)t;

   if (_klass_is_exact != a->_klass_is_exact ||

       _instance_id != a->_instance_id)  return false;

   ciObject* one = const_oop();

   ciObject* two = a->const_oop();

   if (one == NULL || two == NULL) {

     return (one == two) && TypePtr::eq(t);

   } else {

     return one->equals(two) && TypePtr::eq(t);

   }

 }

 //------------------------------hash-------------------------------------------

 // Type-specific hashing function.

 int TypeOopPtr::hash(void) const {

   return

     (const_oop() ? const_oop()->hash() : 0) +

     _klass_is_exact +

     _instance_id +

     TypePtr::hash();

 }

 //------------------------------dump2------------------------------------------

 #ifndef PRODUCT

 void TypeOopPtr::dump2( Dict &d, uint depth, outputStream *st ) const {

   st->print("oopptr:%s", ptr_msg[_ptr]);

   if( _klass_is_exact ) st->print(":exact");

   if( const_oop() ) st->print(INTPTR_FORMAT, const_oop());

   switch( _offset ) {

   case OffsetTop: st->print("+top"); break;

   case OffsetBot: st->print("+any"); break;

   case         0: break;

   default:        st->print("+%d",_offset); break;

   }

   if (_instance_id != UNKNOWN_INSTANCE)

     st->print(",iid=%d",_instance_id);

 }

 #endif

 //------------------------------singleton--------------------------------------

 // TRUE if Type is a singleton type, FALSE otherwise.   Singletons are simple

 // constants

 bool TypeOopPtr::singleton(void) const {

   // detune optimizer to not generate constant oop + constant offset as a constant!

   // TopPTR, Null, AnyNull, Constant are all singletons

   return (_offset == 0) && !below_centerline(_ptr);

 }

 //------------------------------xadd_offset------------------------------------

 int TypeOopPtr::xadd_offset( int offset ) const {

   // Adding to 'TOP' offset?  Return 'TOP'!

   if( _offset == OffsetTop || offset == OffsetTop ) return OffsetTop;

   // Adding to 'BOTTOM' offset?  Return 'BOTTOM'!

   if( _offset == OffsetBot || offset == OffsetBot ) return OffsetBot;

   // assert( _offset >= 0 && _offset+offset >= 0, "" );

   // It is possible to construct a negative offset during PhaseCCP

   return _offset+offset;        // Sum valid offsets

 }

 //------------------------------add_offset-------------------------------------

 const TypePtr *TypeOopPtr::add_offset( int offset ) const {

   return make( _ptr, xadd_offset(offset) );

 }

 const TypeNarrowOop* TypeOopPtr::make_narrowoop() const {

   return TypeNarrowOop::make(this);

 }

 int TypeOopPtr::meet_instance(int iid) const {

   if (iid == 0) {

     return (_instance_id < 0)  ? _instance_id : UNKNOWN_INSTANCE;

   } else if (_instance_id == UNKNOWN_INSTANCE) {

     return (iid < 0)  ? iid : UNKNOWN_INSTANCE;

   } else {

     return (_instance_id == iid) ? iid : UNKNOWN_INSTANCE;

   }

 }

 //=============================================================================

 // Convenience common pre-built types.

 const TypeInstPtr *TypeInstPtr::NOTNULL;

 const TypeInstPtr *TypeInstPtr::BOTTOM;

 const TypeInstPtr *TypeInstPtr::MIRROR;

 const TypeInstPtr *TypeInstPtr::MARK;

 const TypeInstPtr *TypeInstPtr::KLASS;

 //------------------------------TypeInstPtr-------------------------------------

 TypeInstPtr::TypeInstPtr(PTR ptr, ciKlass* k, bool xk, ciObject* o, int off, int instance_id)

  : TypeOopPtr(InstPtr, ptr, k, xk, o, off, instance_id), _name(k->name()) {

    assert(k != NULL &&

           (k->is_loaded() || o == NULL),

           "cannot have constants with non-loaded klass");

 };

 //------------------------------make-------------------------------------------

 const TypeInstPtr *TypeInstPtr::make(PTR ptr,

                                      ciKlass* k,

                                      bool xk,

                                      ciObject* o,

                                      int offset,

                                      int instance_id) {

   assert( !k->is_loaded() || k->is_instance_klass() ||

           k->is_method_klass(), "Must be for instance or method");

   // Either const_oop() is NULL or else ptr is Constant

   assert( (!o && ptr != Constant) || (o && ptr == Constant),

           "constant pointers must have a value supplied" );

   // Ptr is never Null

   assert( ptr != Null, "NULL pointers are not typed" );

   if (instance_id != UNKNOWN_INSTANCE)

     xk = true;  // instances are always exactly typed

   if (!UseExactTypes)  xk = false;

   if (ptr == Constant) {

     // Note:  This case includes meta-object constants, such as methods.

     xk = true;

   } else if (k->is_loaded()) {

     ciInstanceKlass* ik = k->as_instance_klass();

     if (!xk && ik->is_final())     xk = true;   // no inexact final klass

     if (xk && ik->is_interface())  xk = false;  // no exact interface

   }

   // Now hash this baby

   TypeInstPtr *result =

     (TypeInstPtr*)(new TypeInstPtr(ptr, k, xk, o ,offset, instance_id))->hashcons();

   return result;

 }

 //------------------------------cast_to_ptr_type-------------------------------

 const Type *TypeInstPtr::cast_to_ptr_type(PTR ptr) const {

   if( ptr == _ptr ) return this;

   // Reconstruct _sig info here since not a problem with later lazy

   // construction, _sig will show up on demand.

   return make(ptr, klass(), klass_is_exact(), const_oop(), _offset);

 }

 //-----------------------------cast_to_exactness-------------------------------

 const Type *TypeInstPtr::cast_to_exactness(bool klass_is_exact) const {

   if( klass_is_exact == _klass_is_exact ) return this;

   if (!UseExactTypes)  return this;

   if (!_klass->is_loaded())  return this;

   ciInstanceKlass* ik = _klass->as_instance_klass();

   if( (ik->is_final() || _const_oop) )  return this;  // cannot clear xk

   if( ik->is_interface() )              return this;  // cannot set xk

   return make(ptr(), klass(), klass_is_exact, const_oop(), _offset, _instance_id);

 }

 //-----------------------------cast_to_instance-------------------------------

 const TypeOopPtr *TypeInstPtr::cast_to_instance(int instance_id) const {

   if( instance_id == _instance_id) return this;

   bool exact = (instance_id == UNKNOWN_INSTANCE) ? _klass_is_exact : true;

   return make(ptr(), klass(), exact, const_oop(), _offset, instance_id);

 }

 //------------------------------xmeet_unloaded---------------------------------

 // Compute the MEET of two InstPtrs when at least one is unloaded.

 // Assume classes are different since called after check for same name/class-loader

 const TypeInstPtr *TypeInstPtr::xmeet_unloaded(const TypeInstPtr *tinst) const {

     int off = meet_offset(tinst->offset());

     PTR ptr = meet_ptr(tinst->ptr());

     const TypeInstPtr *loaded    = is_loaded() ? this  : tinst;

     const TypeInstPtr *unloaded  = is_loaded() ? tinst : this;

     if( loaded->klass()->equals(ciEnv::current()->Object_klass()) ) {

       //

       // Meet unloaded class with java/lang/Object

       //

       // Meet

       //          |                     Unloaded Class

       //  Object  |   TOP    |   AnyNull | Constant |   NotNull |  BOTTOM   |

       //  ===================================================================

       //   TOP    | ..........................Unloaded......................|

       //  AnyNull |  U-AN    |................Unloaded......................|

       // Constant | ... O-NN .................................. |   O-BOT   |

       //  NotNull | ... O-NN .................................. |   O-BOT   |

       //  BOTTOM  | ........................Object-BOTTOM ..................|

       //

       assert(loaded->ptr() != TypePtr::Null, "insanity check");

       //

       if(      loaded->ptr() == TypePtr::TopPTR ) { return unloaded; }

       else if (loaded->ptr() == TypePtr::AnyNull) { return TypeInstPtr::make( ptr, unloaded->klass() ); }

       else if (loaded->ptr() == TypePtr::BotPTR ) { return TypeInstPtr::BOTTOM; }

       else if (loaded->ptr() == TypePtr::Constant || loaded->ptr() == TypePtr::NotNull) {

         if (unloaded->ptr() == TypePtr::BotPTR  ) { return TypeInstPtr::BOTTOM;  }

         else                                      { return TypeInstPtr::NOTNULL; }

       }

       else if( unloaded->ptr() == TypePtr::TopPTR )  { return unloaded; }

       return unloaded->cast_to_ptr_type(TypePtr::AnyNull)->is_instptr();

     }

     // Both are unloaded, not the same class, not Object

     // Or meet unloaded with a different loaded class, not java/lang/Object

     if( ptr != TypePtr::BotPTR ) {

       return TypeInstPtr::NOTNULL;

     }

     return TypeInstPtr::BOTTOM;

 }