/*

 * 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/callnode.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(PhaseGVN* phase) {

  Node* dom = dominating_cast(phase);

  if (dom != NULL) {

    assert(_carry_dependency, "only for casts that carry a dependency");

    return dom;

  }

  if (_carry_dependency) {

    return this;

  }

  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(PhaseGVN* 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;

}

uint ConstraintCastNode::cmp(const Node &n) const {

  return TypeNode::cmp(n) && ((ConstraintCastNode&)n)._carry_dependency == _carry_dependency;

}

uint ConstraintCastNode::size_of() const {

  return sizeof(*this);

}

Node* ConstraintCastNode::make_cast(int opcode, Node* c, Node *n, const Type *t, bool carry_dependency) {

  switch(opcode) {

  case Op_CastII: {

    Node* cast = new CastIINode(n, t, carry_dependency);

    cast->set_req(0, c);

    return cast;

  }

  case Op_CastPP: {

    Node* cast = new CastPPNode(n, t, carry_dependency);

    cast->set_req(0, c);

    return cast;

  }

  case Op_CheckCastPP: return new CheckCastPPNode(c, n, t, carry_dependency);

  default:

    fatal("Bad opcode %d", opcode);

  }

  return NULL;

}

TypeNode* ConstraintCastNode::dominating_cast(PhaseTransform *phase) const {

  if (!carry_dependency()) {

    return NULL;

  }

  Node* val = in(1);

  Node* ctl = in(0);

  int opc = Opcode();

  if (ctl == NULL) {

    return NULL;

  }

  for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) {

    Node* u = val->fast_out(i);

    if (u != this &&

        u->Opcode() == opc &&

        u->in(0) != NULL &&

        u->bottom_type()->higher_equal(type())) {

      if (phase->is_dominator(u->in(0), ctl)) {

        return u->as_Type();

      }

      if (is_CheckCastPP() && u->in(1)->is_Proj() && u->in(1)->in(0)->is_Allocate() &&

          u->in(0)->is_Proj() && u->in(0)->in(0)->is_Initialize() &&

          u->in(1)->in(0)->as_Allocate()->initialization() == u->in(0)->in(0)) {

        // CheckCastPP following an allocation always dominates all

        // use of the allocation result

        return u->as_Type();

      }

    }

  }

  return NULL;

}

#ifndef PRODUCT

void ConstraintCastNode::dump_spec(outputStream *st) const {

  TypeNode::dump_spec(st);

  if (_carry_dependency) {

    st->print(" carry dependency");

  }

}

#endif

const Type* CastIINode::Value(PhaseGVN* phase) const {

  const Type *res = ConstraintCastNode::Value(phase);

  // Try to improve the type of the CastII if we recognize a CmpI/If

  // pattern.

  if (_carry_dependency) {

    if (in(0) != NULL && in(0)->in(0) != NULL && in(0)->in(0)->is_If()) {

      assert(in(0)->is_IfFalse() || in(0)->is_IfTrue(), "should be If proj");

      Node* proj = in(0);

      if (proj->in(0)->in(1)->is_Bool()) {

        Node* b = proj->in(0)->in(1);

        if (b->in(1)->Opcode() == Op_CmpI) {

          Node* cmp = b->in(1);

          if (cmp->in(1) == in(1) && phase->type(cmp->in(2))->isa_int()) {

            const TypeInt* in2_t = phase->type(cmp->in(2))->is_int();

            const Type* t = TypeInt::INT;

            BoolTest test = b->as_Bool()->_test;

            if (proj->is_IfFalse()) {

              test = test.negate();

            }

            BoolTest::mask m = test._test;

            jlong lo_long = min_jint;

            jlong hi_long = max_jint;

            if (m == BoolTest::le || m == BoolTest::lt) {

              hi_long = in2_t->_hi;

              if (m == BoolTest::lt) {

                hi_long -= 1;

              }

            } else if (m == BoolTest::ge || m == BoolTest::gt) {

              lo_long = in2_t->_lo;

              if (m == BoolTest::gt) {

                lo_long += 1;

              }

            } else if (m == BoolTest::eq) {

              lo_long = in2_t->_lo;

              hi_long = in2_t->_hi;

            } else if (m == BoolTest::ne) {

              // can't do any better

            } else {

              stringStream ss;

              test.dump_on(&ss);

              fatal("unexpected comparison %s", ss.as_string());

            }

            int lo_int = (int)lo_long;

            int hi_int = (int)hi_long;

            if (lo_long != (jlong)lo_int) {

              lo_int = min_jint;

            }

            if (hi_long != (jlong)hi_int) {

              hi_int = max_jint;

            }

            t = TypeInt::make(lo_int, hi_int, Type::WidenMax);

            res = res->filter_speculative(t);

            return res;

          }

        }

      }

    }

  }

  return res;

}

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

  Node* progress = ConstraintCastNode::Ideal(phase, can_reshape);

  if (progress != NULL) {

    return progress;

  }

  // transform:

  // (CastII (AddI x const)) -> (AddI (CastII x) const)

  // So the AddI has a chance to be optimized out

  if (in(1)->Opcode() == Op_AddI) {

    Node* in2 = in(1)->in(2);

    const TypeInt* in2_t = phase->type(in2)->isa_int();

    if (in2_t != NULL && in2_t->singleton()) {

      int in2_const = in2_t->_lo;

      const TypeInt* current_type = _type->is_int();

      jlong new_lo_long = ((jlong)current_type->_lo) - in2_const;

      jlong new_hi_long = ((jlong)current_type->_hi) - in2_const;

      int new_lo = (int)new_lo_long;

      int new_hi = (int)new_hi_long;

      if (((jlong)new_lo) == new_lo_long && ((jlong)new_hi) == new_hi_long) {

        Node* in1 = in(1)->in(1);

        CastIINode* new_cast = (CastIINode*)clone();

        AddINode* new_add = (AddINode*)in(1)->clone();

        new_cast->set_type(TypeInt::make(new_lo, new_hi, current_type->_widen));

        new_cast->set_req(1, in1);

        new_add->set_req(1, phase->transform(new_cast));

        return new_add;

      }

    }

  }

  // Similar to ConvI2LNode::Ideal() for the same reasons

  if (can_reshape && !phase->C->major_progress()) {

    const TypeInt* this_type = this->type()->is_int();

    const TypeInt* in_type = phase->type(in(1))->isa_int();

    if (in_type != NULL && this_type != NULL &&

        (in_type->_lo != this_type->_lo ||

         in_type->_hi != this_type->_hi)) {

      int lo1 = this_type->_lo;

      int hi1 = this_type->_hi;

      int w1  = this_type->_widen;

      if (lo1 >= 0) {

        // Keep a range assertion of >=0.

        lo1 = 0;        hi1 = max_jint;

      } else if (hi1 < 0) {

        // Keep a range assertion of <0.

        lo1 = min_jint; hi1 = -1;

      } else {

        lo1 = min_jint; hi1 = max_jint;

      }

      const TypeInt* wtype = TypeInt::make(MAX2(in_type->_lo, lo1),

                                           MIN2(in_type->_hi, hi1),

                                           MAX2((int)in_type->_widen, w1));

      if (wtype != type()) {

        set_type(wtype);

        return this;

      }

    }

  }

  return NULL;

}

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

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

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

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

  Node* dom = dominating_cast(phase);

  if (dom != NULL) {

    assert(_carry_dependency, "only for casts that carry a dependency");

    return dom;

  }

  if (_carry_dependency) {

    return this;

  }

  // 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(PhaseGVN* 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) {

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

      assert(jptr, "");

      result = !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;

}

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

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

const Type* CastX2PNode::Value(PhaseGVN* 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) {

    dispX = new SubXNode(phase->MakeConX(0), phase->transform(dispX));

  }

  return new AddPNode(phase->C->top(),

                      phase->transform(new CastX2PNode(base)),

                      phase->transform(dispX));

}

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(PhaseGVN* phase) {

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

  return this;

}

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

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

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

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

  return this;

}