/*

 * 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/countbitsnode.hpp"

#include "opto/opcodes.hpp"

#include "opto/phaseX.hpp"

#include "opto/type.hpp"

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

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

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

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

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

  if (ti && ti->is_con()) {

    jint i = ti->get_con();

    // HD, Figure 5-6

    if (i == 0)

    return TypeInt::make(BitsPerInt);

    int n = 1;

    unsigned int x = i;

    if (x >> 16 == 0) { n += 16; x <<= 16; }

    if (x >> 24 == 0) { n +=  8; x <<=  8; }

    if (x >> 28 == 0) { n +=  4; x <<=  4; }

    if (x >> 30 == 0) { n +=  2; x <<=  2; }

    n -= x >> 31;

    return TypeInt::make(n);

  }

  return TypeInt::INT;

}

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

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

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

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

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

  if (tl && tl->is_con()) {

    jlong l = tl->get_con();

    // HD, Figure 5-6

    if (l == 0)

    return TypeInt::make(BitsPerLong);

    int n = 1;

    unsigned int x = (((julong) l) >> 32);

    if (x == 0) { n += 32; x = (int) l; }

    if (x >> 16 == 0) { n += 16; x <<= 16; }

    if (x >> 24 == 0) { n +=  8; x <<=  8; }

    if (x >> 28 == 0) { n +=  4; x <<=  4; }

    if (x >> 30 == 0) { n +=  2; x <<=  2; }

    n -= x >> 31;

    return TypeInt::make(n);

  }

  return TypeInt::INT;

}

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

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

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

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

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

  if (ti && ti->is_con()) {

    jint i = ti->get_con();

    // HD, Figure 5-14

    int y;

    if (i == 0)

    return TypeInt::make(BitsPerInt);

    int n = 31;

    y = i << 16; if (y != 0) { n = n - 16; i = y; }

    y = i <<  8; if (y != 0) { n = n -  8; i = y; }

    y = i <<  4; if (y != 0) { n = n -  4; i = y; }

    y = i <<  2; if (y != 0) { n = n -  2; i = y; }

    y = i <<  1; if (y != 0) { n = n -  1; }

    return TypeInt::make(n);

  }

  return TypeInt::INT;

}

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

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

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

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

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

  if (tl && tl->is_con()) {

    jlong l = tl->get_con();

    // HD, Figure 5-14

    int x, y;

    if (l == 0)

    return TypeInt::make(BitsPerLong);

    int n = 63;

    y = (int) l; if (y != 0) { n = n - 32; x = y; } else x = (((julong) l) >> 32);

    y = x << 16; if (y != 0) { n = n - 16; x = y; }

    y = x <<  8; if (y != 0) { n = n -  8; x = y; }

    y = x <<  4; if (y != 0) { n = n -  4; x = y; }

    y = x <<  2; if (y != 0) { n = n -  2; x = y; }

    y = x <<  1; if (y != 0) { n = n -  1; }

    return TypeInt::make(n);

  }

  return TypeInt::INT;

}