/*

 * Copyright (c) 2016, 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

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 */

#include "precompiled.hpp"

#include "utilities/bitMap.inline.hpp"

#include "utilities/copy.hpp"

#include "utilities/debug.hpp"

#include "utilities/globalDefinitions.hpp"

#include <stdlib.h>

#include "unittest.hpp"

typedef BitMap::idx_t idx_t;

typedef BitMap::bm_word_t bm_word_t;

class BitMapMemory {

private:

  idx_t _words;

  bm_word_t* _memory;

public:

  BitMapMemory(idx_t bits) :

    _words(BitMap::calc_size_in_words(bits)),

    _memory(static_cast<bm_word_t*>(malloc(_words * sizeof(bm_word_t))))

  { }

  ~BitMapMemory() {

    free(_memory);

  }

  BitMapView make_view(idx_t bits, bm_word_t value) {

    vmassert(BitMap::calc_size_in_words(bits) <= _words, "invalid request");

    STATIC_ASSERT(sizeof(bm_word_t) == sizeof(HeapWord));

    Copy::fill_to_aligned_words((HeapWord*)_memory, _words, value);

    return BitMapView(_memory, bits);

  }

  bm_word_t* memory() { return _memory; }

};

const idx_t aligned_size = 4 * BitsPerWord;

const idx_t unaligned_size = aligned_size - (BitsPerWord / 2);

static bm_word_t make_even_bits() {

  bm_word_t result = 1;

  while (true) {

    bm_word_t next = (result << 2) | 1;

    if (next == result) {

      return result;

    }

    result = next;

  }

}

const bm_word_t even_bits = make_even_bits();

const bm_word_t odd_bits = ~even_bits;

const bm_word_t one_bits = ~bm_word_t(0);

const bm_word_t zero_bits = 0;

// Scoped set a clear bit and restore to clear.

class WithBitSet {

private:

  BitMap& _bm;

  idx_t _index;

public:

  WithBitSet(BitMap& bm, idx_t index) : _bm(bm), _index(index) {

    // Failure may indicate test bug; can't use ASSERT_xxx in constructor.

    EXPECT_FALSE(_bm.at(_index));

    bm.set_bit(_index);

  }

  ~WithBitSet() {

    _bm.clear_bit(_index);

  }

};

// Scoped clear a set bit and restore to set.

class WithBitClear {

private:

  BitMap& _bm;

  idx_t _index;

public:

  WithBitClear(BitMap& bm, idx_t index) : _bm(bm), _index(index) {

    // Failure may indicate test bug; can't use ASSERT_xxx in constructor.

    EXPECT_TRUE(_bm.at(_index));

    bm.clear_bit(_index);

  }

  ~WithBitClear() {

    _bm.set_bit(_index);

  }

};

//////////////////////////////////////////////////////////////////////////////

// bool is_same(const BitMap& bits);

TEST(BitMap, is_same__aligned) {

  BitMapMemory mx(aligned_size);

  BitMapMemory my(aligned_size);

  BitMapView x = mx.make_view(aligned_size, even_bits);

  BitMapView y = my.make_view(aligned_size, even_bits);

  EXPECT_TRUE(x.is_same(y));

  WithBitClear wbc(x, aligned_size / 2);

  EXPECT_FALSE(x.is_same(y));

}

TEST(BitMap, is_same__unaligned) {

  BitMapMemory mx(aligned_size);

  BitMapMemory my(aligned_size);

  BitMapView x = mx.make_view(unaligned_size, even_bits);

  BitMapView y = my.make_view(unaligned_size, even_bits);

  // Check that a difference beyond the end of x/y doesn't count.

  {

    BitMapView aligned = BitMapView(mx.memory(), aligned_size);

    const idx_t index = aligned_size - 2;

    STATIC_ASSERT(unaligned_size <= index);

    WithBitClear wbc(aligned, index);

    EXPECT_TRUE(x.is_same(y));

  }

  // Check that a difference in the final partial word does count.

  {

    idx_t index = unaligned_size - 2;

    ASSERT_LE(BitMap::word_align_down(unaligned_size), index);

    WithBitClear wbc(y, index);

    EXPECT_FALSE(x.is_same(y));

  }

}

//////////////////////////////////////////////////////////////////////////////

// bool is_full();

// bool is_empty();

TEST(BitMap, is_full_or_empty__aligned) {

  BitMapMemory mx(aligned_size);

  {

    BitMapView x = mx.make_view(aligned_size, even_bits);

    EXPECT_FALSE(x.is_full());

    EXPECT_FALSE(x.is_empty());

  }

  {

    BitMapView x = mx.make_view(aligned_size, zero_bits);

    EXPECT_FALSE(x.is_full());

    EXPECT_TRUE(x.is_empty());

  }

  {

    BitMapView x = mx.make_view(aligned_size, one_bits);

    EXPECT_TRUE(x.is_full());

    EXPECT_FALSE(x.is_empty());

  }

}

TEST(BitMap, is_full__unaligned) {

  BitMapMemory mx(aligned_size);

  BitMapView x = mx.make_view(unaligned_size, one_bits);

  EXPECT_TRUE(x.is_full());

  // Check that a missing bit beyond the end doesn't count.

  {

    idx_t index = aligned_size - 1;

    BitMapView aligned = BitMapView(mx.memory(), aligned_size);

    WithBitClear wcb(aligned, index);

    EXPECT_FALSE(aligned.is_full());

    EXPECT_TRUE(x.is_full());

  }

  // Check that a missing bit in the final partial word does count.

  {

    WithBitClear wcb(x, unaligned_size - 1);

    EXPECT_FALSE(x.is_full());

  }

}

TEST(BitMap, is_empty__unaligned) {

  BitMapMemory mx(aligned_size);

  BitMapView x = mx.make_view(unaligned_size, zero_bits);

  EXPECT_TRUE(x.is_empty());

  // Check that a set bit beyond the end doesn't count.

  {

    idx_t index = aligned_size - 1;

    BitMapView aligned = BitMapView(mx.memory(), aligned_size);

    WithBitSet wbs(aligned, index);

    EXPECT_FALSE(aligned.is_empty());

    EXPECT_TRUE(x.is_empty());

  }

  // Check that a set bit in the final partial word does count.

  {

    WithBitSet wbs(x, unaligned_size - 1);

    EXPECT_FALSE(x.is_empty());

  }

}

//////////////////////////////////////////////////////////////////////////////

// bool contains(const BitMap& bits);

TEST(BitMap, contains__aligned) {

  BitMapMemory mx(aligned_size);

  BitMapMemory my(aligned_size);

  BitMapView x = mx.make_view(aligned_size, even_bits);

  BitMapView y = my.make_view(aligned_size, even_bits);

  EXPECT_TRUE(x.contains(y));

  WithBitClear wbc(x, aligned_size / 2);

  EXPECT_FALSE(x.contains(y));

}

TEST(BitMap, contains__unaligned) {

  BitMapMemory mx(aligned_size);

  BitMapMemory my(aligned_size);

  BitMapView x = mx.make_view(unaligned_size, even_bits);

  BitMapView y = my.make_view(unaligned_size, even_bits);

  // Check that a missing bit beyond the end of x doesn't count.

  {

    BitMapView aligned = BitMapView(mx.memory(), aligned_size);

    const idx_t index = aligned_size - 2;

    STATIC_ASSERT(unaligned_size <= index);

    WithBitClear wbc(aligned, index);

    EXPECT_TRUE(x.contains(y));

  }

  // Check that a missing bit in the final partial word does count.

  {

    idx_t index = unaligned_size - 2;

    ASSERT_LE(BitMap::word_align_down(unaligned_size), index);

    WithBitClear wbc(x, index);

    EXPECT_FALSE(x.contains(y));

  }

}

//////////////////////////////////////////////////////////////////////////////

// bool intersects(const BitMap& bits);

TEST(BitMap, intersects__aligned) {

  BitMapMemory mx(aligned_size);

  BitMapMemory my(aligned_size);

  BitMapView x = mx.make_view(aligned_size, even_bits);

  BitMapView y = my.make_view(aligned_size, zero_bits);

  EXPECT_FALSE(x.intersects(y));

  ASSERT_TRUE(x.at(aligned_size / 2));

  WithBitSet wbs(y, aligned_size / 2);

  EXPECT_TRUE(x.intersects(y));

}

TEST(BitMap, intersects__unaligned) {

  BitMapMemory mx(aligned_size);

  BitMapMemory my(aligned_size);

  BitMapView x = mx.make_view(unaligned_size, even_bits);

  BitMapView y = my.make_view(unaligned_size, zero_bits);

  EXPECT_FALSE(x.intersects(y));

  // Check that adding a bit beyond the end of y doesn't count.

  {

    BitMapView aligned_x = BitMapView(mx.memory(), aligned_size);

    BitMapView aligned_y = BitMapView(my.memory(), aligned_size);

    const idx_t index = aligned_size - 2;

    STATIC_ASSERT(unaligned_size <= index);

    ASSERT_TRUE(aligned_x.at(index));

    WithBitSet wbs(aligned_y, index);

    EXPECT_FALSE(x.intersects(y));

  }

  // Check that adding a bit in the final partial word does count.

  {

    idx_t index = unaligned_size - 2;

    ASSERT_LE(BitMap::word_align_down(unaligned_size), index);

    ASSERT_TRUE(x.at(index));

    WithBitSet wbs(y, index);

    EXPECT_TRUE(x.intersects(y));

  }

}

//////////////////////////////////////////////////////////////////////////////

// void set_from(const BitMap& bits);

// void set_union(const BitMap& bits);

// void set_difference(const BitMap& bits);

// void set_intersection(const BitMap& bits);

//

// bool set_union_with_result(const BitMap& bits);

// bool set_difference_with_result(const BitMap& bits);

// bool set_intersection_with_result(const BitMap& bits);

static void check_tail_unmodified(BitMapMemory& mem,

                                  idx_t bits,

                                  bm_word_t fill_word) {

  if (!BitMap::is_word_aligned(bits)) {

    idx_t last_word_bit_index = BitMap::word_align_down(bits);

    idx_t last_word_index = BitMap::calc_size_in_words(last_word_bit_index);

    bm_word_t last_word = mem.memory()[last_word_index];

    idx_t shift = bits - last_word_bit_index;

    EXPECT_EQ(fill_word >> shift, last_word >> shift);

  }

}

static void check_mod_setop(void (BitMap::*f)(const BitMap&),

                            idx_t bits,

                            bm_word_t wx,

                            bm_word_t wy,

                            bm_word_t wexp) {

  BitMapMemory mx(bits);

  BitMapMemory my(bits);

  BitMapMemory mexp(bits);

  BitMapView x = mx.make_view(bits, wx);

  BitMapView y = my.make_view(bits, wy);

  BitMapView exp = mexp.make_view(bits, wexp);

  (x.*f)(y);

  EXPECT_TRUE(exp.is_same(x));

  check_tail_unmodified(mx, bits, wx);

}

static void check_mod_setop_with_result(bool (BitMap::*f)(const BitMap&),

                                        idx_t bits,

                                        bm_word_t wx,

                                        bm_word_t wy,

                                        bm_word_t wexp) {

  BitMapMemory mx(bits);

  BitMapMemory my(bits);

  BitMapMemory mexp(bits);

  BitMapView x = mx.make_view(bits, wx);

  BitMapView y = my.make_view(bits, wy);

  BitMapView exp = mexp.make_view(bits, wexp);

  bool value = (x.*f)(y);

  EXPECT_EQ(value, wx != wexp);

  EXPECT_TRUE(exp.is_same(x));

  check_tail_unmodified(mx, bits, wx);

}

#define CHECK_MOD_SETOP_AUX(checker, name, x, y, exp)   \

  TEST(BitMap, name ## __ ## x ## _ ## y) {             \

    checker(&BitMap::name, aligned_size,                \

            x ## _bits, y ## _bits, exp ## _bits);      \

    checker(&BitMap::name, unaligned_size,              \

            x ## _bits, y ## _bits, exp ## _bits);      \

  }

#define CHECK_MOD_SETOP(name, x, y, exp) \

  CHECK_MOD_SETOP_AUX(check_mod_setop, name, x, y, exp)

#define CHECK_MOD_SETOP_WITH_RESULT(name, x, y, exp) \

  CHECK_MOD_SETOP_AUX(check_mod_setop_with_result, name, x, y, exp)

#define CHECK_MOD_SETOPS(name, x, y, exp)                       \

  CHECK_MOD_SETOP(name, x, y, exp)                              \

  CHECK_MOD_SETOP_WITH_RESULT(name ## _with_result, x, y, exp)

CHECK_MOD_SETOP(set_from, even, even, even)

CHECK_MOD_SETOP(set_from, even, odd, odd)

CHECK_MOD_SETOP(set_from, even, one, one)

CHECK_MOD_SETOP(set_from, even, zero, zero)

CHECK_MOD_SETOPS(set_union, even, even, even)

CHECK_MOD_SETOPS(set_union, even, odd, one)

CHECK_MOD_SETOPS(set_union, even, one, one)

CHECK_MOD_SETOPS(set_union, even, zero, even)

CHECK_MOD_SETOPS(set_difference, even, even, zero)

CHECK_MOD_SETOPS(set_difference, even, odd, even)

CHECK_MOD_SETOPS(set_difference, even, one, zero)

CHECK_MOD_SETOPS(set_difference, even, zero, even)

CHECK_MOD_SETOPS(set_intersection, even, even, even)

CHECK_MOD_SETOPS(set_intersection, even, odd, zero)

CHECK_MOD_SETOPS(set_intersection, even, one, even)

CHECK_MOD_SETOPS(set_intersection, even, zero, zero)