com32/include/x86/bitops.h

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2010-2011 Intel Corporation; author: H. Peter Anvin
   4  *
   5  *   Permission is hereby granted, free of charge, to any person
   6  *   obtaining a copy of this software and associated documentation
   7  *   files (the "Software"), to deal in the Software without
   8  *   restriction, including without limitation the rights to use,
   9  *   copy, modify, merge, publish, distribute, sublicense, and/or
  10  *   sell copies of the Software, and to permit persons to whom
  11  *   the Software is furnished to do so, subject to the following
  12  *   conditions:
  13  *
  14  *   The above copyright notice and this permission notice shall
  15  *   be included in all copies or substantial portions of the Software.
  16  *
  17  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  *   OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  * ----------------------------------------------------------------------- */
  27
  28 /*
  29  * x86/bitops.h
  30  *
  31  * Simple bitwise operations
  32  */
  33
  34 #ifndef _X86_BITOPS_H
  35 #define _X86_BITOPS_H
  36
  37 static inline void set_bit(long __bit, void *__bitmap)
  38 {
  39     asm volatile("bts %1,%0"
  40                  : "+m" (*(unsigned char *)__bitmap)
  41                  : "Ir" (__bit) : "memory");
  42 }
  43
  44 static inline void clr_bit(long __bit, void *__bitmap)
  45 {
  46     asm volatile("btc %1,%0"
  47                  : "+m" (*(unsigned char *)__bitmap)
  48                  : "Ir" (__bit) : "memory");
  49 }
  50
  51 static inline _Bool __purefunc test_bit(long __bit, const void *__bitmap)
  52 {
  53     _Bool __r;
  54
  55 #ifdef __GCC_ASM_FLAG_OUTPUTS__
  56     asm("bt %2,%1"
  57         : "=@ccc" (__r)
  58         : "m" (*(const unsigned char *)__bitmap), "Ir" (__bit));
  59 #else
  60     asm("bt %2,%1; setc %0"
  61         : "=qm" (__r)
  62         : "m" (*(const unsigned char *)__bitmap), "Ir" (__bit));
  63 #endif
  64
  65     return __r;
  66 }
  67
  68 #endif /* _X86_BITOPS_H */