/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "opto/addnode.hpp"

#include "opto/castnode.hpp"

#include "opto/connode.hpp"

#include "opto/matcher.hpp"

#include "opto/phaseX.hpp"

#include "opto/subnode.hpp"

#include "opto/type.hpp"

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

// If input is already higher or equal to cast type, then this is an identity.

Node *ConstraintCastNode::Identity( PhaseTransform *phase ) {

  return phase->type(in(1))->higher_equal_speculative(_type) ? in(1) : this;

}

//------------------------------Value------------------------------------------

// Take 'join' of input and cast-up type

const Type *ConstraintCastNode::Value( PhaseTransform *phase ) const {

  if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;

  const Type* ft = phase->type(in(1))->filter_speculative(_type);

#ifdef ASSERT

  // Previous versions of this function had some special case logic,

  // which is no longer necessary.  Make sure of the required effects.

  switch (Opcode()) {

    case Op_CastII:

    {

      const Type* t1 = phase->type(in(1));

      if( t1 == Type::TOP )  assert(ft == Type::TOP, "special case #1");

      const Type* rt = t1->join_speculative(_type);

      if (rt->empty())       assert(ft == Type::TOP, "special case #2");

      break;

    }

    case Op_CastPP:

    if (phase->type(in(1)) == TypePtr::NULL_PTR &&

        _type->isa_ptr() && _type->is_ptr()->_ptr == TypePtr::NotNull)

    assert(ft == Type::TOP, "special case #3");

    break;

  }

#endif //ASSERT

  return ft;

}

//------------------------------Ideal------------------------------------------

// Return a node which is more "ideal" than the current node.  Strip out

// control copies

Node *ConstraintCastNode::Ideal(PhaseGVN *phase, bool can_reshape){

  return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;

}

//------------------------------Ideal_DU_postCCP-------------------------------

// Throw away cast after constant propagation

Node *ConstraintCastNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {

  const Type *t = ccp->type(in(1));

  ccp->hash_delete(this);

  set_type(t);                   // Turn into ID function

  ccp->hash_insert(this);

  return this;

}

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

//------------------------------Ideal_DU_postCCP-------------------------------

// If not converting int->oop, throw away cast after constant propagation

Node *CastPPNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {

  const Type *t = ccp->type(in(1));

  if (!t->isa_oop_ptr() || ((in(1)->is_DecodeN()) && Matcher::gen_narrow_oop_implicit_null_checks())) {

    return NULL; // do not transform raw pointers or narrow oops

  }

  return ConstraintCastNode::Ideal_DU_postCCP(ccp);

}

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

//------------------------------Identity---------------------------------------

// If input is already higher or equal to cast type, then this is an identity.

Node *CheckCastPPNode::Identity( PhaseTransform *phase ) {

  // Toned down to rescue meeting at a Phi 3 different oops all implementing

  // the same interface.  CompileTheWorld starting at 502, kd12rc1.zip.

  return (phase->type(in(1)) == phase->type(this)) ? in(1) : this;

}

//------------------------------Value------------------------------------------

// Take 'join' of input and cast-up type, unless working with an Interface

const Type *CheckCastPPNode::Value( PhaseTransform *phase ) const {

  if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;

  const Type *inn = phase->type(in(1));

  if( inn == Type::TOP ) return Type::TOP;  // No information yet

  const TypePtr *in_type   = inn->isa_ptr();

  const TypePtr *my_type   = _type->isa_ptr();

  const Type *result = _type;

  if( in_type != NULL && my_type != NULL ) {

    TypePtr::PTR   in_ptr    = in_type->ptr();

    if( in_ptr == TypePtr::Null ) {

      result = in_type;

    } else if( in_ptr == TypePtr::Constant ) {

      // Casting a constant oop to an interface?

      // (i.e., a String to a Comparable?)

      // Then return the interface.

      const TypeOopPtr *jptr = my_type->isa_oopptr();

      assert( jptr, "" );

      result =  (jptr->klass()->is_interface() || !in_type->higher_equal(_type))

      ? my_type->cast_to_ptr_type( TypePtr::NotNull )

      : in_type;

    } else {

      result =  my_type->cast_to_ptr_type( my_type->join_ptr(in_ptr) );

    }

  }

  // This is the code from TypePtr::xmeet() that prevents us from

  // having 2 ways to represent the same type. We have to replicate it

  // here because we don't go through meet/join.

  if (result->remove_speculative() == result->speculative()) {

    result = result->remove_speculative();

  }

  // Same as above: because we don't go through meet/join, remove the

  // speculative type if we know we won't use it.

  return result->cleanup_speculative();

  // JOIN NOT DONE HERE BECAUSE OF INTERFACE ISSUES.

  // FIX THIS (DO THE JOIN) WHEN UNION TYPES APPEAR!

  //

  // Remove this code after overnight run indicates no performance

  // loss from not performing JOIN at CheckCastPPNode

  //

  // const TypeInstPtr *in_oop = in->isa_instptr();

  // const TypeInstPtr *my_oop = _type->isa_instptr();

  // // If either input is an 'interface', return destination type

  // assert (in_oop == NULL || in_oop->klass() != NULL, "");

  // assert (my_oop == NULL || my_oop->klass() != NULL, "");

  // if( (in_oop && in_oop->klass()->is_interface())

  //   ||(my_oop && my_oop->klass()->is_interface()) ) {

  //   TypePtr::PTR  in_ptr = in->isa_ptr() ? in->is_ptr()->_ptr : TypePtr::BotPTR;

  //   // Preserve cast away nullness for interfaces

  //   if( in_ptr == TypePtr::NotNull && my_oop && my_oop->_ptr == TypePtr::BotPTR ) {

  //     return my_oop->cast_to_ptr_type(TypePtr::NotNull);

  //   }

  //   return _type;

  // }

  //

  // // Neither the input nor the destination type is an interface,

  //

  // // history: JOIN used to cause weird corner case bugs

  // //          return (in == TypeOopPtr::NULL_PTR) ? in : _type;

  // // JOIN picks up NotNull in common instance-of/check-cast idioms, both oops.

  // // JOIN does not preserve NotNull in other cases, e.g. RawPtr vs InstPtr

  // const Type *join = in->join(_type);

  // // Check if join preserved NotNull'ness for pointers

  // if( join->isa_ptr() && _type->isa_ptr() ) {

  //   TypePtr::PTR join_ptr = join->is_ptr()->_ptr;

  //   TypePtr::PTR type_ptr = _type->is_ptr()->_ptr;

  //   // If there isn't any NotNull'ness to preserve

  //   // OR if join preserved NotNull'ness then return it

  //   if( type_ptr == TypePtr::BotPTR  || type_ptr == TypePtr::Null ||

  //       join_ptr == TypePtr::NotNull || join_ptr == TypePtr::Constant ) {

  //     return join;

  //   }

  //   // ELSE return same old type as before

  //   return _type;

  // }

  // // Not joining two pointers

  // return join;

}

//------------------------------Ideal------------------------------------------

// Return a node which is more "ideal" than the current node.  Strip out

// control copies

Node *CheckCastPPNode::Ideal(PhaseGVN *phase, bool can_reshape){

  return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;

}

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

//------------------------------Value------------------------------------------

const Type *CastX2PNode::Value( PhaseTransform *phase ) const {

  const Type* t = phase->type(in(1));

  if (t == Type::TOP) return Type::TOP;

  if (t->base() == Type_X && t->singleton()) {

    uintptr_t bits = (uintptr_t) t->is_intptr_t()->get_con();

    if (bits == 0)   return TypePtr::NULL_PTR;

    return TypeRawPtr::make((address) bits);

  }

  return CastX2PNode::bottom_type();

}

//------------------------------Idealize---------------------------------------

static inline bool fits_in_int(const Type* t, bool but_not_min_int = false) {

  if (t == Type::TOP)  return false;

  const TypeX* tl = t->is_intptr_t();

  jint lo = min_jint;

  jint hi = max_jint;

  if (but_not_min_int)  ++lo;  // caller wants to negate the value w/o overflow

  return (tl->_lo >= lo) && (tl->_hi <= hi);

}

static inline Node* addP_of_X2P(PhaseGVN *phase,

                                Node* base,

                                Node* dispX,

                                bool negate = false) {

  if (negate) {

  }

}

Node *CastX2PNode::Ideal(PhaseGVN *phase, bool can_reshape) {

  // convert CastX2P(AddX(x, y)) to AddP(CastX2P(x), y) if y fits in an int

  int op = in(1)->Opcode();

  Node* x;

  Node* y;

  switch (op) {

    case Op_SubX:

    x = in(1)->in(1);

    // Avoid ideal transformations ping-pong between this and AddP for raw pointers.

    if (phase->find_intptr_t_con(x, -1) == 0)

    break;

    y = in(1)->in(2);

    if (fits_in_int(phase->type(y), true)) {

      return addP_of_X2P(phase, x, y, true);

    }

    break;

    case Op_AddX:

    x = in(1)->in(1);

    y = in(1)->in(2);

    if (fits_in_int(phase->type(y))) {

      return addP_of_X2P(phase, x, y);

    }

    if (fits_in_int(phase->type(x))) {

      return addP_of_X2P(phase, y, x);

    }

    break;

  }

  return NULL;

}

//------------------------------Identity---------------------------------------

Node *CastX2PNode::Identity( PhaseTransform *phase ) {

  if (in(1)->Opcode() == Op_CastP2X)  return in(1)->in(1);

  return this;

}

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

//------------------------------Value------------------------------------------

const Type *CastP2XNode::Value( PhaseTransform *phase ) const {

  const Type* t = phase->type(in(1));

  if (t == Type::TOP) return Type::TOP;

  if (t->base() == Type::RawPtr && t->singleton()) {

    uintptr_t bits = (uintptr_t) t->is_rawptr()->get_con();

    return TypeX::make(bits);

  }

  return CastP2XNode::bottom_type();

}

Node *CastP2XNode::Ideal(PhaseGVN *phase, bool can_reshape) {

  return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;

}

//------------------------------Identity---------------------------------------

Node *CastP2XNode::Identity( PhaseTransform *phase ) {

  if (in(1)->Opcode() == Op_CastX2P)  return in(1)->in(1);

  return this;

}