include/uapi/linux/const.h

   1 /* const.h: Macros for dealing with constants.  */
   2
   3 #ifndef _LINUX_CONST_H
   4 #define _LINUX_CONST_H
   5
   6 /* Some constant macros are used in both assembler and
   7  * C code.  Therefore we cannot annotate them always with
   8  * 'UL' and other type specifiers unilaterally.  We
   9  * use the following macros to deal with this.
  10  *
  11  * Similarly, _AT() will cast an expression with a type in C, but
  12  * leave it unchanged in asm.
  13  */
  14
  15 #ifdef __ASSEMBLY__
  16 #define _AC(X,Y)        X
  17 #define _AT(T,X)        X
  18 #else
  19 #define __AC(X,Y)       (X##Y)
  20 #define _AC(X,Y)        __AC(X,Y)
  21 #define _AT(T,X)        ((T)(X))
  22 #endif
  23
  24 #define _BITUL(x)       (_AC(1,UL) << (x))
  25 #define _BITULL(x)      (_AC(1,ULL) << (x))
  26
  27 #endif /* !(_LINUX_CONST_H) */