Utils.cpp

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Digital Voice Modem - Hotspot Firmware
 * GPLv2 Open Source. Use is subject to license terms.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * @package DVM / Hotspot Firmware
 * @derivedfrom MMDVM_HS (https://github.com/g4klx/MMDVM_HS)
 * @license GPLv2 License (https://opensource.org/licenses/GPL-2.0)
 *
 *  Copyright (C) 2015,2020 Jonathan Naylor, G4KLX
 *  Copyright (C) 2017 Andy Uribe, CA6JAU
 *
 */
#include "Utils.h"

// ---------------------------------------------------------------------------
//  Constants/Macros
// ---------------------------------------------------------------------------

const uint8_t BITS_TABLE[] = {
#   define B2(n) n,     n+1,     n+1,     n+2
#   define B4(n) B2(n), B2(n+1), B2(n+1), B2(n+2)
#   define B6(n) B4(n), B4(n+1), B4(n+1), B4(n+2)
    B6(0), B6(1), B6(1), B6(2)
};

// ---------------------------------------------------------------------------
//  Global Functions
// ---------------------------------------------------------------------------

/* Returns the count of bits in the passed 8 byte value. */

uint8_t countBits8(uint8_t bits)
{
    return BITS_TABLE[bits];
}

/* Returns the count of bits in the passed 16 byte value. */

uint8_t countBits16(uint16_t bits)
{
    uint8_t* p = (uint8_t*)&bits;
    uint8_t n = 0U;
    n += BITS_TABLE[p[0U]];
    n += BITS_TABLE[p[1U]];
    return n;
}

/* Returns the count of bits in the passed 32 byte value. */

uint8_t countBits32(uint32_t bits)
{
    uint8_t* p = (uint8_t*)&bits;
    uint8_t n = 0U;
    n += BITS_TABLE[p[0U]];
    n += BITS_TABLE[p[1U]];
    n += BITS_TABLE[p[2U]];
    n += BITS_TABLE[p[3U]];
    return n;
}

/* Returns the count of bits in the passed 64 byte value. */

uint8_t countBits64(uint64_t bits)
{
    uint8_t* p = (uint8_t*)&bits;
    uint8_t n = 0U;
    n += BITS_TABLE[p[0U]];
    n += BITS_TABLE[p[1U]];
    n += BITS_TABLE[p[2U]];
    n += BITS_TABLE[p[3U]];
    n += BITS_TABLE[p[4U]];
    n += BITS_TABLE[p[5U]];
    n += BITS_TABLE[p[6U]];
    n += BITS_TABLE[p[7U]];
    return n;
}