/****************************************************************************

Copyright(c) 2019 by Aerospace C.Power (Chongqing) Microelectronics. ALL RIGHTS RESERVED.

This Information is proprietary to Aerospace C.Power (Chongqing) Microelectronics and MAY NOT
be copied by any method or incorporated into another program without
the express written consent of Aerospace C.Power. This Information or any portion
thereof remains the property of Aerospace C.Power. The Information contained herein
is believed to be accurate and Aerospace C.Power assumes no responsibility or
liability for its use in any way and conveys no license or title under
any patent or copyright and makes no representation or warranty that this
Information is free from patent or copyright infringement.

****************************************************************************/

/* os shim includes */
#include "os_types.h"

/* common includes */
#include "iot_bitops.h"

/* table used for ffs and ffz operation */
const IRAM_ATTR uint8_t iot_bitops_ffs_tab[IOT_BITOPS_TAB_SIZE] = {
0, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
6, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
7, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
6, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
8, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
6, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
7, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
6, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1,
5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1 };

/* table used for fls and ffz operation */
const IRAM_ATTR uint8_t iot_bitops_fls_tab[IOT_BITOPS_TAB_SIZE] = {
0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8 };

/* table used for cbs and cbz operation */
const uint8_t iot_bitops_cbs_tab[IOT_BITOPS_TAB_SIZE] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 };

/* find the first bit set to 1 for non-zero byte */
static inline uint8_t __iot_bitops_ffs(uint8_t tmp)
{
    uint8_t b = 1;

    if (!(tmp & 0x0F)) {
        tmp >>= 4;
        b += 4;
    }
    if (!(tmp & 0x03)) {
        tmp >>= 2;
        b += 2;
    }
    if (!(tmp & 0x01)) {
        b += 1;
    }

    return b;
}

/* find the last bit set to 1 for non-zero byte */
static inline uint8_t __iot_bitops_fls(uint8_t tmp)
{
    uint8_t b = 8;

    if (!(tmp & 0xF0)) {
        tmp <<= 4;
        b -= 4;
    }
    if (!(tmp & 0xC0)) {
        tmp <<= 2;
        b -= 2;
    }
    if (!(tmp & 0x80)) {
        b -= 1;
    }

    return b;
}

/* find number of bits set to 1 for one byte */
static inline uint8_t __iot_bitops_cbs(uint8_t tmp)
{
    uint8_t b = 0;

    for (b = 0; tmp; b++) {
        /* clear the least significant bit set */
        tmp &= tmp - 1;
    }

    return b;
}

void iot_bitops_init()
{
    uint32_t i;

    for (i = 1; i < IOT_BITOPS_TAB_SIZE; i++) {
        if (iot_bitops_ffs_tab[i] != __iot_bitops_ffs((uint8_t)i))
            IOT_ASSERT(0);
    }
    for (i = 1; i < IOT_BITOPS_TAB_SIZE; i++) {
        if (iot_bitops_fls_tab[i] != __iot_bitops_fls((uint8_t)i))
            IOT_ASSERT(0);
    }
    for (i = 1; i < IOT_BITOPS_TAB_SIZE; i++) {
        if (iot_bitops_cbs_tab[i] != __iot_bitops_cbs((uint8_t)i))
            IOT_ASSERT(0);
    }
}