/*

 * Copyright (c) 2008-2024 Stefan Krah. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#ifndef LIBMPDEC_BITS_H_

#define LIBMPDEC_BITS_H_

#include "mpdecimal.h"

/* Check if n is a power of 2. */

static inline int

ispower2(mpd_size_t n)

{

    return n != 0 && (n & (n-1)) == 0;

}

Unexecuted instantiation: mpdecimal.c:ispower2

Unexecuted instantiation: convolute.c:ispower2

Unexecuted instantiation: fnt.c:ispower2

Unexecuted instantiation: numbertheory.c:ispower2

Unexecuted instantiation: sixstep.c:ispower2

Unexecuted instantiation: transpose.c:ispower2

Unexecuted instantiation: difradix2.c:ispower2

#if defined(ANSI)

/*

 * Return the most significant bit position of n from 0 to 31 (63).

 * Assumptions: n != 0.

 */

static inline int

mpd_bsr(mpd_size_t n)

{

    int pos = 0;

    mpd_size_t tmp;

#ifdef CONFIG_64

    tmp = n >> 32;

    if (tmp != 0) { n = tmp; pos += 32; }

#endif

    tmp = n >> 16;

    if (tmp != 0) { n = tmp; pos += 16; }

    tmp = n >> 8;

    if (tmp != 0) { n = tmp; pos += 8; }

    tmp = n >> 4;

    if (tmp != 0) { n = tmp; pos += 4; }

    tmp = n >> 2;

    if (tmp != 0) { n = tmp; pos += 2; }

    tmp = n >> 1;

    if (tmp != 0) { n = tmp; pos += 1; }

    return pos + (int)n - 1;

}

/*

 * Return the least significant bit position of n from 0 to 31 (63).

 * Assumptions: n != 0.

 */

static inline int

mpd_bsf(mpd_size_t n)

{

    int pos;

#ifdef CONFIG_64

    pos = 63;

    if (n & 0x00000000FFFFFFFFULL) { pos -= 32; } else { n >>= 32; }

    if (n & 0x000000000000FFFFULL) { pos -= 16; } else { n >>= 16; }

    if (n & 0x00000000000000FFULL) { pos -=  8; } else { n >>=  8; }

    if (n & 0x000000000000000FULL) { pos -=  4; } else { n >>=  4; }

    if (n & 0x0000000000000003ULL) { pos -=  2; } else { n >>=  2; }

    if (n & 0x0000000000000001ULL) { pos -=  1; }

#else

    pos = 31;

    if (n & 0x000000000000FFFFUL) { pos -= 16; } else { n >>= 16; }

    if (n & 0x00000000000000FFUL) { pos -=  8; } else { n >>=  8; }

    if (n & 0x000000000000000FUL) { pos -=  4; } else { n >>=  4; }

    if (n & 0x0000000000000003UL) { pos -=  2; } else { n >>=  2; }

    if (n & 0x0000000000000001UL) { pos -=  1; }

#endif

    return pos;

}

/* END ANSI */

#elif defined(ASM)

/*

 * Bit scan reverse. Assumptions: a != 0.

 */

static inline int

mpd_bsr(mpd_size_t a)

{

    mpd_size_t retval;

    __asm__ (

#ifdef CONFIG_64

        "bsrq %1, %0\n\t"

#else

        "bsr %1, %0\n\t"

#endif

        :"=r" (retval)

        :"r" (a)

        :"cc"

    );

    return (int)retval;

}

Unexecuted instantiation: mpdecimal.c:mpd_bsr

Unexecuted instantiation: convolute.c:mpd_bsr

Unexecuted instantiation: fnt.c:mpd_bsr

Unexecuted instantiation: numbertheory.c:mpd_bsr

Unexecuted instantiation: sixstep.c:mpd_bsr

Unexecuted instantiation: transpose.c:mpd_bsr

Unexecuted instantiation: difradix2.c:mpd_bsr

/*

 * Bit scan forward. Assumptions: a != 0.

 */

static inline int

mpd_bsf(mpd_size_t a)

{

    mpd_size_t retval;

    __asm__ (

#ifdef CONFIG_64

        "bsfq %1, %0\n\t"

#else

        "bsf %1, %0\n\t"

#endif

        :"=r" (retval)

        :"r" (a)

        :"cc"

    );

    return (int)retval;

}

Unexecuted instantiation: mpdecimal.c:mpd_bsf

Unexecuted instantiation: convolute.c:mpd_bsf

Unexecuted instantiation: fnt.c:mpd_bsf

Unexecuted instantiation: numbertheory.c:mpd_bsf

Unexecuted instantiation: sixstep.c:mpd_bsf

Unexecuted instantiation: transpose.c:mpd_bsf

Unexecuted instantiation: difradix2.c:mpd_bsf

/* END ASM */

#elif defined(MASM)

#include <intrin.h>

/*

 * Bit scan reverse. Assumptions: a != 0.

 */

static inline int __cdecl

mpd_bsr(mpd_size_t a)

{

    unsigned long retval;

#ifdef CONFIG_64

    _BitScanReverse64(&retval, a);

#else

    _BitScanReverse(&retval, a);

#endif

    return (int)retval;

}

/*

 * Bit scan forward. Assumptions: a != 0.

 */

static inline int __cdecl

mpd_bsf(mpd_size_t a)

{

    unsigned long retval;

#ifdef CONFIG_64

    _BitScanForward64(&retval, a);

#else

    _BitScanForward(&retval, a);

#endif

    return (int)retval;

}

/* END MASM (_MSC_VER) */

#else

  #error "missing preprocessor definitions"

#endif /* BSR/BSF */

#endif /* LIBMPDEC_BITS_H_ */