LXR linux/arch/parisc/include/uapi/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
   9static 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
  19static 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
  29static 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*/
  52static 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 */
  67