linux/arch/parisc/include/uapi/asm/swab.h
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   1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2#ifndef _PARISC_SWAB_H
   3#define _PARISC_SWAB_H
   4
   5#include <asm/bitsperlong.h>
   6#include <linux/types.h>
   7#include <linux/compiler.h>
   8
   9#define __SWAB_64_THRU_32__
  10
  11static inline __attribute_const__ __u16 __arch_swab16(__u16 x)
  12{
  13        __asm__("dep %0, 15, 8, %0\n\t"         /* deposit 00ab -> 0bab */
  14                "shd %%r0, %0, 8, %0"           /* shift 000000ab -> 00ba */
  15                : "=r" (x)
  16                : "0" (x));
  17        return x;
  18}
  19#define __arch_swab16 __arch_swab16
  20
  21static inline __attribute_const__ __u32 __arch_swab24(__u32 x)
  22{
  23        __asm__("shd %0, %0, 8, %0\n\t"         /* shift xabcxabc -> cxab */
  24                "dep %0, 15, 8, %0\n\t"         /* deposit cxab -> cbab */
  25                "shd %%r0, %0, 8, %0"           /* shift 0000cbab -> 0cba */
  26                : "=r" (x)
  27                : "0" (x));
  28        return x;
  29}
  30
  31static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
  32{
  33        unsigned int temp;
  34        __asm__("shd %0, %0, 16, %1\n\t"        /* shift abcdabcd -> cdab */
  35                "dep %1, 15, 8, %1\n\t"         /* deposit cdab -> cbab */
  36                "shd %0, %1, 8, %0"             /* shift abcdcbab -> dcba */
  37                : "=r" (x), "=&r" (temp)
  38                : "0" (x));
  39        return x;
  40}
  41#define __arch_swab32 __arch_swab32
  42
  43#if __BITS_PER_LONG > 32
  44/*
  45** From "PA-RISC 2.0 Architecture", HP Professional Books.
  46** See Appendix I page 8 , "Endian Byte Swapping".
  47**
  48** Pretty cool algorithm: (* == zero'd bits)
  49**      PERMH   01234567 -> 67452301 into %0
  50**      HSHL    67452301 -> 7*5*3*1* into %1
  51**      HSHR    67452301 -> *6*4*2*0 into %0
  52**      OR      %0 | %1  -> 76543210 into %0 (all done!)
  53*/
  54static inline __attribute_const__ __u64 __arch_swab64(__u64 x)
  55{
  56        __u64 temp;
  57        __asm__("permh,3210 %0, %0\n\t"
  58                "hshl %0, 8, %1\n\t"
  59                "hshr,u %0, 8, %0\n\t"
  60                "or %1, %0, %0"
  61                : "=r" (x), "=&r" (temp)
  62                : "0" (x));
  63        return x;
  64}
  65#define __arch_swab64 __arch_swab64
  66#endif /* __BITS_PER_LONG > 32 */
  67
  68#endif /* _PARISC_SWAB_H */
  69