2 This file is a part of libcds - Concurrent Data Structures library
4 (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
6 Source code repo: http://github.com/khizmax/libcds/
7 Download: http://sourceforge.net/projects/libcds/files/
9 Redistribution and use in source and binary forms, with or without
10 modification, are permitted provided that the following conditions are met:
12 * Redistributions of source code must retain the above copyright notice, this
13 list of conditions and the following disclaimer.
15 * Redistributions in binary form must reproduce the above copyright notice,
16 this list of conditions and the following disclaimer in the documentation
17 and/or other materials provided with the distribution.
19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
23 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
26 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 #ifndef CDSLIB_COMPILER_GCC_X86_BITOP_H
32 #define CDSLIB_COMPILER_GCC_X86_BITOP_H
36 namespace bitop { namespace platform { namespace gcc { namespace x86 {
37 // MSB - return index (1..32) of most significant bit in nArg. If nArg == 0 return 0
38 # define cds_bitop_msb32_DEFINED
39 static inline int msb32( uint32_t nArg )
42 __asm__ __volatile__ (
43 "bsrl %[nArg], %[nRet] ;\n\t"
45 "xorl %[nRet], %[nRet] ;\n\t"
46 "subl $1, %[nRet] ;\n\t"
48 "addl $1, %[nRet] ;\n\t"
56 # define cds_bitop_msb32nz_DEFINED
57 static inline int msb32nz( uint32_t nArg )
61 __asm__ __volatile__ (
62 "bsrl %[nArg], %[nRet] ;"
70 // LSB - return index (0..31) of least significant bit in nArg. If nArg == 0 return -1U
71 # define cds_bitop_lsb32_DEFINED
72 static inline int lsb32( uint32_t nArg )
76 __asm__ __volatile__ (
77 "bsfl %[nArg], %[nRet] ;"
79 "xorl %[nRet], %[nRet] ;"
91 // LSB - return index (0..31) of least significant bit in nArg.
92 // Condition: nArg != 0
93 # define cds_bitop_lsb32nz_DEFINED
94 static inline int lsb32nz( uint32_t nArg )
98 __asm__ __volatile__ (
99 "bsfl %[nArg], %[nRet] ;"
107 }} // namespace gcc::x86
109 using namespace gcc::x86;
111 }}} // namespace cds::bitop::platform
114 #endif // #ifndef CDSLIB_ARH_X86_GCC_BITOP_H