/*

 * Copyright (c) 2014, 2015, 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/convertnode.hpp"

#include "opto/matcher.hpp"

#include "opto/phaseX.hpp"

#include "opto/subnode.hpp"

#include "runtime/sharedRuntime.hpp"

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

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

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

  if( t == Type::TOP ) return in(1);

  if( t == TypeInt::ZERO ) return in(1);

  if( t == TypeInt::ONE ) return in(1);

  if( t == TypeInt::BOOL ) return in(1);

  return this;

}

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

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

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

  if( t == TypeInt::ZERO ) return TypeInt::ZERO;

  if( t == TypePtr::NULL_PTR ) return TypeInt::ZERO;

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

  if( tp != NULL ) {

    if( tp->ptr() == TypePtr::AnyNull ) return Type::TOP;

    if( tp->ptr() == TypePtr::Constant) return TypeInt::ONE;

    if (tp->ptr() == TypePtr::NotNull)  return TypeInt::ONE;

    return TypeInt::BOOL;

  }

  if (t->base() != Type::Int) return TypeInt::BOOL;

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

  if( ti->_hi < 0 || ti->_lo > 0 ) return TypeInt::ONE;

  return TypeInt::BOOL;

}

// The conversions operations are all Alpha sorted.  Please keep it that way!

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

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

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

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

  if( t == Type::DOUBLE ) return Type::FLOAT;

  const TypeD *td = t->is_double_constant();

  return TypeF::make( (float)td->getd() );

}

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

// Float's can be converted to doubles with no loss of bits.  Hence

// converting a float to a double and back to a float is a NOP.

  return (in(1)->Opcode() == Op_ConvF2D) ? in(1)->in(1) : this;

}

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

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

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

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

  if( t == Type::DOUBLE ) return TypeInt::INT;

  const TypeD *td = t->is_double_constant();

  return TypeInt::make( SharedRuntime::d2i( td->getd() ) );

}

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

// If converting to an int type, skip any rounding nodes

Node *ConvD2INode::Ideal(PhaseGVN *phase, bool can_reshape) {

  if( in(1)->Opcode() == Op_RoundDouble )

  set_req(1,in(1)->in(1));

  return NULL;

}

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

// Int's can be converted to doubles with no loss of bits.  Hence

// converting an integer to a double and back to an integer is a NOP.

  return (in(1)->Opcode() == Op_ConvI2D) ? in(1)->in(1) : this;

}

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

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

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

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

  if( t == Type::DOUBLE ) return TypeLong::LONG;

  const TypeD *td = t->is_double_constant();

  return TypeLong::make( SharedRuntime::d2l( td->getd() ) );

}

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

  // Remove ConvD2L->ConvL2D->ConvD2L sequences.

  if( in(1)       ->Opcode() == Op_ConvL2D &&

     in(1)->in(1)->Opcode() == Op_ConvD2L )

  return in(1)->in(1);

  return this;

}

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

// If converting to an int type, skip any rounding nodes

Node *ConvD2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {

  if( in(1)->Opcode() == Op_RoundDouble )

  set_req(1,in(1)->in(1));

  return NULL;

}

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

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

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

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

  if( t == Type::FLOAT ) return Type::DOUBLE;

  const TypeF *tf = t->is_float_constant();

  return TypeD::make( (double)tf->getf() );

}

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

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

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

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

  if( t == Type::FLOAT ) return TypeInt::INT;

  const TypeF *tf = t->is_float_constant();

  return TypeInt::make( SharedRuntime::f2i( tf->getf() ) );

}

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

  // Remove ConvF2I->ConvI2F->ConvF2I sequences.

  if( in(1)       ->Opcode() == Op_ConvI2F &&

     in(1)->in(1)->Opcode() == Op_ConvF2I )

  return in(1)->in(1);

  return this;

}

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

// If converting to an int type, skip any rounding nodes

Node *ConvF2INode::Ideal(PhaseGVN *phase, bool can_reshape) {

  if( in(1)->Opcode() == Op_RoundFloat )

  set_req(1,in(1)->in(1));

  return NULL;

}

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

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

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

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

  if( t == Type::FLOAT ) return TypeLong::LONG;

  const TypeF *tf = t->is_float_constant();

  return TypeLong::make( SharedRuntime::f2l( tf->getf() ) );

}

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

  // Remove ConvF2L->ConvL2F->ConvF2L sequences.

  if( in(1)       ->Opcode() == Op_ConvL2F &&

     in(1)->in(1)->Opcode() == Op_ConvF2L )

  return in(1)->in(1);

  return this;

}

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

// If converting to an int type, skip any rounding nodes

Node *ConvF2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {

  if( in(1)->Opcode() == Op_RoundFloat )

  set_req(1,in(1)->in(1));

  return NULL;

}

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

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

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

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

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

  if( ti->is_con() ) return TypeD::make( (double)ti->get_con() );

  return bottom_type();

}

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

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

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

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

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

  if( ti->is_con() ) return TypeF::make( (float)ti->get_con() );

  return bottom_type();

}

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

  // Remove ConvI2F->ConvF2I->ConvI2F sequences.

  if( in(1)       ->Opcode() == Op_ConvF2I &&

     in(1)->in(1)->Opcode() == Op_ConvI2F )

  return in(1)->in(1);

  return this;

}

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

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

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

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

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

  const Type* tl = TypeLong::make(ti->_lo, ti->_hi, ti->_widen);

  // Join my declared type against my incoming type.

  tl = tl->filter(_type);

  return tl;

}

#ifdef _LP64

static inline bool long_ranges_overlap(jlong lo1, jlong hi1,

                                       jlong lo2, jlong hi2) {

  // Two ranges overlap iff one range's low point falls in the other range.

  return (lo2 <= lo1 && lo1 <= hi2) || (lo1 <= lo2 && lo2 <= hi1);

}

#endif

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

Node *ConvI2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {

  const TypeLong* this_type = this->type()->is_long();

  Node* this_changed = NULL;

  // If _major_progress, then more loop optimizations follow.  Do NOT

  // remove this node's type assertion until no more loop ops can happen.

  // The progress bit is set in the major loop optimizations THEN comes the

  // call to IterGVN and any chance of hitting this code.  Cf. Opaque1Node.

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

    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)) {

          // Although this WORSENS the type, it increases GVN opportunities,

          // because I2L nodes with the same input will common up, regardless

          // of slightly differing type assertions.  Such slight differences

          // arise routinely as a result of loop unrolling, so this is a

          // post-unrolling graph cleanup.  Choose a type which depends only

          // on my input.  (Exception:  Keep a range assertion of >=0 or <0.)

          jlong lo1 = this_type->_lo;

          jlong hi1 = this_type->_hi;

          int   w1  = this_type->_widen;

          if (lo1 != (jint)lo1 ||

              hi1 != (jint)hi1 ||

              lo1 > hi1) {

            // Overflow leads to wraparound, wraparound leads to range saturation.

            lo1 = min_jint; hi1 = max_jint;

          } else 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 TypeLong* wtype = TypeLong::make(MAX2((jlong)in_type->_lo, lo1),

                                                 MIN2((jlong)in_type->_hi, hi1),

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

          if (wtype != type()) {

            set_type(wtype);

            // Note: this_type still has old type value, for the logic below.

            this_changed = this;

          }

        }

  }

#ifdef _LP64

  // Convert ConvI2L(AddI(x, y)) to AddL(ConvI2L(x), ConvI2L(y)) ,

  // but only if x and y have subranges that cannot cause 32-bit overflow,

  // under the assumption that x+y is in my own subrange this->type().

  // This assumption is based on a constraint (i.e., type assertion)

  // established in Parse::array_addressing or perhaps elsewhere.

  // This constraint has been adjoined to the "natural" type of

  // the incoming argument in(0).  We know (because of runtime

  // checks) - that the result value I2L(x+y) is in the joined range.

  // Hence we can restrict the incoming terms (x, y) to values such

  // that their sum also lands in that range.

  // This optimization is useful only on 64-bit systems, where we hope

  // the addition will end up subsumed in an addressing mode.

  // It is necessary to do this when optimizing an unrolled array

  // copy loop such as x[i++] = y[i++].

  // On 32-bit systems, it's better to perform as much 32-bit math as

  // possible before the I2L conversion, because 32-bit math is cheaper.

  // There's no common reason to "leak" a constant offset through the I2L.

  // Addressing arithmetic will not absorb it as part of a 64-bit AddL.

  Node* z = in(1);

  int op = z->Opcode();

  if (op == Op_AddI || op == Op_SubI) {

    Node* x = z->in(1);

    Node* y = z->in(2);

    assert (x != z && y != z, "dead loop in ConvI2LNode::Ideal");

    if (phase->type(x) == Type::TOP)  return this_changed;

    if (phase->type(y) == Type::TOP)  return this_changed;

    const TypeInt*  tx = phase->type(x)->is_int();

    const TypeInt*  ty = phase->type(y)->is_int();

    const TypeLong* tz = this_type;

    jlong xlo = tx->_lo;

    jlong xhi = tx->_hi;

    jlong ylo = ty->_lo;

    jlong yhi = ty->_hi;

    jlong zlo = tz->_lo;

    jlong zhi = tz->_hi;

    jlong vbit = CONST64(1) << BitsPerInt;

    int widen =  MAX2(tx->_widen, ty->_widen);

    if (op == Op_SubI) {

      jlong ylo0 = ylo;

      ylo = -yhi;

      yhi = -ylo0;

    }

    // See if x+y can cause positive overflow into z+2**32

    if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo+vbit, zhi+vbit)) {

      return this_changed;

    }

    // See if x+y can cause negative overflow into z-2**32

    if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo-vbit, zhi-vbit)) {

      return this_changed;

    }

    // Now it's always safe to assume x+y does not overflow.

    // This is true even if some pairs x,y might cause overflow, as long

    // as that overflow value cannot fall into [zlo,zhi].

    // Confident that the arithmetic is "as if infinite precision",

    // we can now use z's range to put constraints on those of x and y.

    // The "natural" range of x [xlo,xhi] can perhaps be narrowed to a

    // more "restricted" range by intersecting [xlo,xhi] with the

    // range obtained by subtracting y's range from the asserted range

    // of the I2L conversion.  Here's the interval arithmetic algebra:

    //    x == z-y == [zlo,zhi]-[ylo,yhi] == [zlo,zhi]+[-yhi,-ylo]

    //    => x in [zlo-yhi, zhi-ylo]

    //    => x in [zlo-yhi, zhi-ylo] INTERSECT [xlo,xhi]

    //    => x in [xlo MAX zlo-yhi, xhi MIN zhi-ylo]

    jlong rxlo = MAX2(xlo, zlo - yhi);

    jlong rxhi = MIN2(xhi, zhi - ylo);

    // And similarly, x changing place with y:

    jlong rylo = MAX2(ylo, zlo - xhi);

    jlong ryhi = MIN2(yhi, zhi - xlo);

    if (rxlo > rxhi || rylo > ryhi) {

      return this_changed;  // x or y is dying; don't mess w/ it

    }

    if (op == Op_SubI) {

      jlong rylo0 = rylo;

      rylo = -ryhi;

      ryhi = -rylo0;

    }

    Node* cx = phase->transform( new ConvI2LNode(x, TypeLong::make(rxlo, rxhi, widen)) );

    Node* cy = phase->transform( new ConvI2LNode(y, TypeLong::make(rylo, ryhi, widen)) );

    switch (op) {

      case Op_AddI:  return new AddLNode(cx, cy);

      case Op_SubI:  return new SubLNode(cx, cy);

      default:       ShouldNotReachHere();

    }

  }

#endif //_LP64

  return this_changed;

}

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

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

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

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

  const TypeLong *tl = t->is_long();

  if( tl->is_con() ) return TypeD::make( (double)tl->get_con() );

  return bottom_type();

}

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

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

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

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

  const TypeLong *tl = t->is_long();

  if( tl->is_con() ) return TypeF::make( (float)tl->get_con() );

  return bottom_type();

}

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

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

  // Convert L2I(I2L(x)) => x

  if (in(1)->Opcode() == Op_ConvI2L)  return in(1)->in(1);

  return this;

}

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

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

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

  const TypeLong *tl = t->is_long();

  if (tl->is_con())

  // Easy case.

  return TypeInt::make((jint)tl->get_con());

  return bottom_type();

}

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

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

// Blow off prior masking to int

Node *ConvL2INode::Ideal(PhaseGVN *phase, bool can_reshape) {

  Node *andl = in(1);

  uint andl_op = andl->Opcode();

  if( andl_op == Op_AndL ) {

    // Blow off prior masking to int

    if( phase->type(andl->in(2)) == TypeLong::make( 0xFFFFFFFF ) ) {

      set_req(1,andl->in(1));

      return this;

    }

  }

  // Swap with a prior add: convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))

  // This replaces an 'AddL' with an 'AddI'.

  if( andl_op == Op_AddL ) {

    // Don't do this for nodes which have more than one user since

    // we'll end up computing the long add anyway.

    if (andl->outcnt() > 1) return NULL;

    Node* x = andl->in(1);

    Node* y = andl->in(2);

    assert( x != andl && y != andl, "dead loop in ConvL2INode::Ideal" );

    if (phase->type(x) == Type::TOP)  return NULL;

    if (phase->type(y) == Type::TOP)  return NULL;

    Node *add1 = phase->transform(new ConvL2INode(x));

    Node *add2 = phase->transform(new ConvL2INode(y));

    return new AddINode(add1,add2);

  }

  // Disable optimization: LoadL->ConvL2I ==> LoadI.

  // It causes problems (sizes of Load and Store nodes do not match)

  // in objects initialization code and Escape Analysis.

  return NULL;

}

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

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

// Remove redundant roundings

  assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");

  // Do not round constants

  if (phase->type(in(1))->base() == Type::FloatCon)  return in(1);

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

  // Redundant rounding

  if( op == Op_RoundFloat ) return in(1);

  // Already rounded

  if( op == Op_Parm ) return in(1);

  if( op == Op_LoadF ) return in(1);

  return this;

}

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

  return phase->type( in(1) );

}

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

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

// Remove redundant roundings.  Incoming arguments are already rounded.

  assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");

  // Do not round constants

  if (phase->type(in(1))->base() == Type::DoubleCon)  return in(1);

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

  // Redundant rounding

  if( op == Op_RoundDouble ) return in(1);

  // Already rounded

  if( op == Op_Parm ) return in(1);

  if( op == Op_LoadD ) return in(1);

  if( op == Op_ConvF2D ) return in(1);

  if( op == Op_ConvI2D ) return in(1);

  return this;

}

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

  return phase->type( in(1) );

}