com32/include/sys/i386/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  * i386 bitops.h
  30  *
  31  * Simple bitwise operations
  32  */
  33 static inline void set_bit(long __bit, void *__bitmap)
  34 {
  35     asm volatile("btsl %1,%0"
  36                  : "+m" (*(unsigned char *)__bitmap)
  37                  : "Ir" (__bit) : "memory");
  38 }
  39
  40 static inline void clr_bit(long __bit, void *__bitmap)
  41 {
  42     asm volatile("btcl %1,%0"
  43                  : "+m" (*(unsigned char *)__bitmap)
  44                  : "Ir" (__bit) : "memory");
  45 }
  46
  47 static inline int __purefunc test_bit(long __bit, const void *__bitmap)
  48 {
  49     unsigned char __r;
  50     asm("btl %2,%1; setc %0"
  51         : "=qm" (__r)
  52         : "m" (*(const unsigned char *)__bitmap), "Ir" (__bit));
  53     return __r;
  54 }