/* crc32_p.h -- Private inline functions and macros shared with

 *              different computation of the CRC-32 checksum

 *              of a data stream.

 * Copyright (C) 2026 Nathan Moinvaziri

 * For conditions of distribution and use, see copyright notice in zlib.h

 */

#ifndef CRC32_P_H

#define CRC32_P_H

#include "crc32_braid_tbl.h"

#define CRC_DO1(c, buf, i) c = crc_table[(c ^ buf[i]) & 0xff] ^ (c >> 8)

#define CRC_DO2(c, buf, i) {CRC_DO1(c, buf, i); CRC_DO1(c, buf, i+1);}

#define CRC_DO4(c, buf, i) {CRC_DO2(c, buf, i); CRC_DO2(c, buf, i+2);}

#define CRC_DO8(c, buf, i) {CRC_DO4(c, buf, i); CRC_DO4(c, buf, i+4);}

Z_FORCEINLINE static uint32_t crc32_copy_small(uint32_t crc, uint8_t *dst, const uint8_t *buf, size_t len,

                                               const int MAX_LEN, const int COPY) {

    if (MAX_LEN >= 8) {

        while (len >= 8) {

            if (COPY) {

                memcpy(dst, buf, 8);

                dst += 8;

            }

            CRC_DO8(crc, buf, 0);

            buf += 8;

            len -= 8;

        }

    }

    if (len & 4) {

        if (COPY) {

            memcpy(dst, buf, 4);

            dst += 4;

        }

        CRC_DO4(crc, buf, 0);

        buf += 4;

    }

    if (len & 2) {

        if (COPY) {

            memcpy(dst, buf, 2);

            dst += 2;

        }

        CRC_DO2(crc, buf, 0);

        buf += 2;

    }

    if (len & 1) {

        if (COPY)

            *dst = *buf;

        CRC_DO1(crc, buf, 0);

    }

    return crc;

}

crc32_pclmulqdq.c:crc32_copy_small

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Source

19

2.82M

                                               const int MAX_LEN, const int COPY) {

20

2.82M

    if (MAX_LEN >= 8) {

21

3.22M

        while (len >= 8) {

22

400k

            if (COPY) {

23

2.13k

                memcpy(dst, buf, 8);

24

2.13k

                dst += 8;

25

2.13k

            }

26

400k

            CRC_DO8(crc, buf, 0);

27

400k

            buf += 8;

28

400k

            len -= 8;

29

400k

        }

30

2.82M

    }

31

2.82M

    if (len & 4) {

32

377k

        if (COPY) {

33

2.02k

            memcpy(dst, buf, 4);

34

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            dst += 4;

35

2.02k

        }

36

377k

        CRC_DO4(crc, buf, 0);

37

377k

        buf += 4;

38

377k

    }

39

2.82M

    if (len & 2) {

40

894k

        if (COPY) {

41

1.99k

            memcpy(dst, buf, 2);

42

1.99k

            dst += 2;

43

1.99k

        }

44

894k

        CRC_DO2(crc, buf, 0);

45

894k

        buf += 2;

46

894k

    }

47

2.82M

    if (len & 1) {

48

1.87M

        if (COPY)

49

1.84k

            *dst = *buf;

50

1.87M

        CRC_DO1(crc, buf, 0);

51

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    }

52

53

2.82M

    return crc;

54

2.82M

}

Unexecuted instantiation: crc32_vpclmulqdq_avx2.c:crc32_copy_small

Unexecuted instantiation: crc32_vpclmulqdq_avx512.c:crc32_copy_small

Unexecuted instantiation: crc32_braid_c.c:crc32_copy_small

Unexecuted instantiation: crc32.c:crc32_copy_small

#endif /* CRC32_P_H */