release/src-rt-6.x.4708/linux/linux-2.6.36/arch/parisc/include/asm/swab.h

   1 #ifndef _PARISC_SWAB_H
   2 #define _PARISC_SWAB_H
   3
   4 #include <linux/types.h>
   5 #include <linux/compiler.h>
   6
   7 #define __SWAB_64_THRU_32__
   8
   9 static inline __attribute_const__ __u16 __arch_swab16(__u16 x)
  10 {
  11         __asm__("dep %0, 15, 8, %0\n\t"         /* deposit 00ab -> 0bab */
  12                 "shd %%r0, %0, 8, %0"           /* shift 000000ab -> 00ba */
  13                 : "=r" (x)
  14                 : "0" (x));
  15         return x;
  16 }
  17 #define __arch_swab16 __arch_swab16
  18
  19 static inline __attribute_const__ __u32 __arch_swab24(__u32 x)
  20 {
  21         __asm__("shd %0, %0, 8, %0\n\t"         /* shift xabcxabc -> cxab */
  22                 "dep %0, 15, 8, %0\n\t"         /* deposit cxab -> cbab */
  23                 "shd %%r0, %0, 8, %0"           /* shift 0000cbab -> 0cba */
  24                 : "=r" (x)
  25                 : "0" (x));
  26         return x;
  27 }
  28
  29 static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
  30 {
  31         unsigned int temp;
  32         __asm__("shd %0, %0, 16, %1\n\t"        /* shift abcdabcd -> cdab */
  33                 "dep %1, 15, 8, %1\n\t"         /* deposit cdab -> cbab */
  34                 "shd %0, %1, 8, %0"             /* shift abcdcbab -> dcba */
  35                 : "=r" (x), "=&r" (temp)
  36                 : "0" (x));
  37         return x;
  38 }
  39 #define __arch_swab32 __arch_swab32
  40
  41 #if BITS_PER_LONG > 32
  42 /*
  43 ** From "PA-RISC 2.0 Architecture", HP Professional Books.
  44 ** See Appendix I page 8 , "Endian Byte Swapping".
  45 **
  46 ** Pretty cool algorithm: (* == zero'd bits)
  47 **      PERMH   01234567 -> 67452301 into %0
  48 **      HSHL    67452301 -> 7*5*3*1* into %1
  49 **      HSHR    67452301 -> *6*4*2*0 into %0
  50 **      OR      %0 | %1  -> 76543210 into %0 (all done!)
  51 */
  52 static inline __attribute_const__ __u64 __arch_swab64(__u64 x)
  53 {
  54         __u64 temp;
  55         __asm__("permh,3210 %0, %0\n\t"
  56                 "hshl %0, 8, %1\n\t"
  57                 "hshr,u %0, 8, %0\n\t"
  58                 "or %1, %0, %0"
  59                 : "=r" (x), "=&r" (temp)
  60                 : "0" (x));
  61         return x;
  62 }
  63 #define __arch_swab64 __arch_swab64
  64 #endif /* BITS_PER_LONG > 32 */
  65
  66 #endif /* _PARISC_SWAB_H */