/* Copyright (C) 2009 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "lib/self_test.h"

#include "lib/bits.h"

#define EQUALS(actual, expected) debug_assert((actual) == (expected))

class TestBits : public CxxTest::TestSuite 
{
public:
	void test_Bit()
	{
		EQUALS(Bit<unsigned>(0), 1);
		EQUALS(Bit<unsigned>(8), 0x100);
		EQUALS(Bit<u32>(31), u32(0x80000000ul));
		EQUALS(Bit<u64>(1), u64(2));
		EQUALS(Bit<u64>(32), u64(0x100000000ull));
		EQUALS(Bit<u64>(63), u64(0x8000000000000000ull));
	}

	void test_IsBitSet()
	{
		EQUALS(IsBitSet(0u, 1), false);
		EQUALS(IsBitSet(1u, 1), false);
		EQUALS(IsBitSet(2u, 1), true);
		EQUALS(IsBitSet<u32>(0xFFFFFFFFul, 0), true);
		EQUALS(IsBitSet<u32>(0xFFFFFFFFul, 31), true);
		EQUALS(IsBitSet<u64>(0xFFFFFFFFFFFFFFFFull, 0), true);
		EQUALS(IsBitSet<u64>(0xFFFFFFFFFFFFFFFFull, 31), true);
		EQUALS(IsBitSet<u64>(0xFFFFFFFFFFFFFFFFull, 32), true);
		EQUALS(IsBitSet<u64>(0xFFFFFFFFFFFFFFFFull, 63), true);
	}

	void test_bit_mask()
	{
		EQUALS(bit_mask<u16>(0), 0);
		EQUALS(bit_mask<u16>(2), 0x3);
		EQUALS(bit_mask<u16>(16), 0xFFFF);
		EQUALS(bit_mask<u32>(0), 0);
		EQUALS(bit_mask<u32>(2), 0x3);
		EQUALS(bit_mask<u32>(32), 0xFFFFFFFFul);
		EQUALS(bit_mask<u64>(0), 0);
		EQUALS(bit_mask<u64>(2), 0x3);
		EQUALS(bit_mask<u64>(32), 0xFFFFFFFFull);
		EQUALS(bit_mask<u64>(64), 0xFFFFFFFFFFFFFFFFull);
	}

	void test_bits()
	{
		EQUALS(bits<u16>(0xFFFF, 0, 15), 0xFFFF);
		EQUALS(bits<u16>(0xFFFF, 0, 7), 0xFF);
		EQUALS(bits<u16>(0xFFFF, 8, 15), 0xFF);
		EQUALS(bits<u16>(0xFFFF, 14, 15), 0x3);
		EQUALS(bits<u16>(0xAA55, 4, 11), 0xA5);
		EQUALS(bits<u16>(0xAA55, 14, 15), 0x2);
		EQUALS(bits<u32>(0ul, 0, 31), 0ul);
		EQUALS(bits<u32>(0xFFFFFFFFul, 0, 31), 0xFFFFFFFFul);
		EQUALS(bits<u64>(0ull, 0, 63), 0ull);
		EQUALS(bits<u64>(0xFFFFFFFFull, 0, 31), 0xFFFFFFFFull);
		EQUALS(bits<u64>(0x0000FFFFFFFF0000ull, 16, 47), 0xFFFFFFFFull);
		EQUALS(bits<u64>(0xFFFFFFFFFFFFFFFFull, 0, 63), 0xFFFFFFFFFFFFFFFFull);
		EQUALS(bits<u64>(0xA5A5A5A5A5A5A5A5ull, 32, 63), 0xA5A5A5A5ull);
	}

	void test_PopulationCount()
	{
		EQUALS(PopulationCount<u8>(0), 0);
		EQUALS(PopulationCount<u8>(4), 1);
		EQUALS(PopulationCount<u8>(0x28), 2);
		EQUALS(PopulationCount<u8>(0xFF), 8);
		EQUALS(PopulationCount<u32>(0x0ul), 0);
		EQUALS(PopulationCount<u32>(0x8ul), 1);
		EQUALS(PopulationCount<u32>(0xFFFFul), 16);
		EQUALS(PopulationCount<u32>(0xFFFFFFFFul), 32);
		EQUALS(PopulationCount<u64>(0x0ull), 0);
		EQUALS(PopulationCount<u64>(0x10ull), 1);
		EQUALS(PopulationCount<u64>(0xFFFFull), 16);
		EQUALS(PopulationCount<u64>(0xFFFFFFFFull), 32);
		EQUALS(PopulationCount<u64>(0xFFFFFFFFFFFFFFFEull), 63);
		EQUALS(PopulationCount<u64>(0xFFFFFFFFFFFFFFFFull), 64);
	}

	void test_is_pow2()
	{
		EQUALS(is_pow2(0u), false);
		EQUALS(is_pow2(~0u), false);
		EQUALS(is_pow2(0x80000001), false);
		EQUALS(is_pow2(1), true);
		EQUALS(is_pow2(1u << 31), true);
	}

	void test_ceil_log2()
	{
		EQUALS(ceil_log2(3u), 2u);
		EQUALS(ceil_log2(0xffffffffu), 32u);
		EQUALS(ceil_log2(1u), 0u);
		EQUALS(ceil_log2(256u), 8u);
		EQUALS(ceil_log2(0x80000000u), 31u);
	}

	void test_floor_log2()
	{
		EQUALS(floor_log2(1.f), 0);
		EQUALS(floor_log2(3.f), 1);
		EQUALS(floor_log2(256.f), 8);
	}

	void test_round_up_to_pow2()
	{
		EQUALS(round_up_to_pow2(0u), 1u);
		EQUALS(round_up_to_pow2(1u), 1u);
		EQUALS(round_up_to_pow2(127u), 128u);
		EQUALS(round_up_to_pow2(128u), 128u);
		EQUALS(round_up_to_pow2(129u), 256u);
	}

	void test_round_up()
	{
		EQUALS(round_up( 0u, 16u), 0u);
		EQUALS(round_up( 4u, 16u), 16u);
		EQUALS(round_up(15u, 16u), 16u);
		EQUALS(round_up(20u, 32u), 32u);
		EQUALS(round_up(29u, 32u), 32u);
		EQUALS(round_up(0x1000u, 0x1000u), 0x1000u);
		EQUALS(round_up(0x1001u, 0x1000u), 0x2000u);
		EQUALS(round_up(0x1900u, 0x1000u), 0x2000u);
	}

	void test_round_down()
	{
		EQUALS(round_down( 0u, 16u), 0u);
		EQUALS(round_down( 4u, 16u), 0u);
		EQUALS(round_down(15u, 16u), 0u);
		EQUALS(round_down(20u, 16u), 16u);
		EQUALS(round_down(29u, 16u), 16u);
		EQUALS(round_down(0x1900u, 0x1000u), 0x1000u);
		EQUALS(round_down(0x2001u, 0x2000u), 0x2000u);
	}
};