/*
    This file is a part of libcds - Concurrent Data Structures library

    (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017

    Source code repo: http://github.com/khizmax/libcds/
    Download: http://sourceforge.net/projects/libcds/files/

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, this
      list of conditions and the following disclaimer.

    * 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 CDSLIB_COMPILER_GCC_AMD64_BITOP_H
#define CDSLIB_COMPILER_GCC_AMD64_BITOP_H

//@cond none
namespace cds {
    namespace bitop { namespace platform { namespace gcc { namespace amd64 {
        // MSB - return index (1..32) of most significant bit in nArg. If nArg == 0 return 0
#        define cds_bitop_msb32_DEFINED
        static inline int msb32( uint32_t nArg )
        {
            int        nRet;
            __asm__ __volatile__ (
                "bsrl        %[nArg], %[nRet]     ;\n\t"
                "jnz        1f                    ;\n\t"
                "xorl        %[nRet], %[nRet]    ;\n\t"
                "subl        $1, %[nRet]         ;\n\t"
                "1:"
                "addl        $1, %[nRet]         ;\n\t"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return nRet;
        }

#        define cds_bitop_msb32nz_DEFINED
        static inline int msb32nz( uint32_t nArg )
        {
            assert( nArg != 0 );
            int        nRet;
            __asm__ __volatile__ (
                "bsrl        %[nArg], %[nRet]    ;"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return nRet;
        }

        // LSB - return index (0..31) of least significant bit in nArg. If nArg == 0 return -1U
#        define cds_bitop_lsb32_DEFINED
        static inline int lsb32( uint32_t nArg )
        {

            int        nRet;
            __asm__ __volatile__ (
                "bsfl        %[nArg], %[nRet]     ;"
                "jnz        1f        ;"
                "xorl        %[nRet], %[nRet]    ;"
                "subl        $1, %[nRet]         ;"
                "1:"
                "addl        $1, %[nRet]         ;"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return nRet;

        }

        // LSB - return index (0..31) of least significant bit in nArg.
        // Condition: nArg != 0
#        define cds_bitop_lsb32nz_DEFINED
        static inline int lsb32nz( uint32_t nArg )
        {
            assert( nArg != 0 );
            int        nRet;
            __asm__ __volatile__ (
                "bsfl        %[nArg], %[nRet]    ;"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return nRet;
        }

#        define cds_bitop_msb64_DEFINED
        static inline int msb64( uint64_t nArg )
        {
            uint64_t  nRet;
            asm volatile (
                "bsrq        %[nArg], %[nRet]     ;\n\t"
                "jnz        1f                    ;\n\t"
                "xorq        %[nRet], %[nRet]    ;\n\t"
                "subq        $1, %[nRet]         ;\n\t"
                "1:"
                "addq        $1, %[nRet]         ;\n\t"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return (int) nRet;
        }

#        define cds_bitop_msb64nz_DEFINED
        static inline int msb64nz( uint64_t nArg )
        {
            assert( nArg != 0 );
            uint64_t nRet;
            __asm__ __volatile__ (
                "bsrq        %[nArg], %[nRet]    ;"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return (int) nRet;
        }

        // LSB - return index (0..31) of least significant bit in nArg. If nArg == 0 return -1U
#        define cds_bitop_lsb64_DEFINED
        static inline int lsb64( uint64_t nArg )
        {
            uint64_t nRet;
            __asm__ __volatile__ (
                "bsfq        %[nArg], %[nRet]     ;"
                "jnz        1f        ;"
                "xorq        %[nRet], %[nRet]    ;"
                "subq        $1, %[nRet]         ;"
                "1:"
                "addq        $1, %[nRet]         ;"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return (int) nRet;

        }

        // LSB - return index (0..31) of least significant bit in nArg.
        // Condition: nArg != 0
#        define cds_bitop_lsb64nz_DEFINED
        static inline int lsb64nz( uint64_t nArg )
        {
            assert( nArg != 0 );
            uint64_t nRet;
            __asm__ __volatile__ (
                "bsfq        %[nArg], %[nRet]    ;"
                : [nRet] "=a" (nRet)
                : [nArg] "r" (nArg)
                : "cc"
                );
            return (int) nRet;
        }


    }} // namespace gcc::amd64

    using namespace gcc::amd64;

    }}}    // namespace cds::bitop::platform

//@endcond

#endif // #ifndef CDSLIB_COMPILER_GCC_AMD64_BITOP_H
