LXR linux/include/linux/bitrev.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_BITREV_H
   3#define _LINUX_BITREV_H
   4
   5#include <linux/types.h>
   6
   7#ifdef CONFIG_HAVE_ARCH_BITREVERSE
   8#include <asm/bitrev.h>
   9
  10#define __bitrev32 __arch_bitrev32
  11#define __bitrev16 __arch_bitrev16
  12#define __bitrev8 __arch_bitrev8
  13
  14#else
  15extern u8 const byte_rev_table[256];
  16static inline u8 __bitrev8(u8 byte)
  17{
  18        return byte_rev_table[byte];
  19}
  20
  21static inline u16 __bitrev16(u16 x)
  22{
  23        return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8);
  24}
  25
  26static inline u32 __bitrev32(u32 x)
  27{
  28        return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16);
  29}
  30
  31#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
  32
  33#define __bitrev8x4(x)  (__bitrev32(swab32(x)))
  34
  35#define __constant_bitrev32(x)  \
  36({                                      \
  37        u32 ___x = x;                   \
  38        ___x = (___x >> 16) | (___x << 16);     \
  39        ___x = ((___x & (u32)0xFF00FF00UL) >> 8) | ((___x & (u32)0x00FF00FFUL) << 8);   \
  40        ___x = ((___x & (u32)0xF0F0F0F0UL) >> 4) | ((___x & (u32)0x0F0F0F0FUL) << 4);   \
  41        ___x = ((___x & (u32)0xCCCCCCCCUL) >> 2) | ((___x & (u32)0x33333333UL) << 2);   \
  42        ___x = ((___x & (u32)0xAAAAAAAAUL) >> 1) | ((___x & (u32)0x55555555UL) << 1);   \
  43        ___x;                                                           \
  44})
  45
  46#define __constant_bitrev16(x)  \
  47({                                      \
  48        u16 ___x = x;                   \
  49        ___x = (___x >> 8) | (___x << 8);       \
  50        ___x = ((___x & (u16)0xF0F0U) >> 4) | ((___x & (u16)0x0F0FU) << 4);     \
  51        ___x = ((___x & (u16)0xCCCCU) >> 2) | ((___x & (u16)0x3333U) << 2);     \
  52        ___x = ((___x & (u16)0xAAAAU) >> 1) | ((___x & (u16)0x5555U) << 1);     \
  53        ___x;                                                           \
  54})
  55
  56#define __constant_bitrev8x4(x) \
  57({                      \
  58        u32 ___x = x;   \
  59        ___x = ((___x & (u32)0xF0F0F0F0UL) >> 4) | ((___x & (u32)0x0F0F0F0FUL) << 4);   \
  60        ___x = ((___x & (u32)0xCCCCCCCCUL) >> 2) | ((___x & (u32)0x33333333UL) << 2);   \
  61        ___x = ((___x & (u32)0xAAAAAAAAUL) >> 1) | ((___x & (u32)0x55555555UL) << 1);   \
  62        ___x;                                                           \
  63})
  64
  65#define __constant_bitrev8(x)   \
  66({                                      \
  67        u8 ___x = x;                    \
  68        ___x = (___x >> 4) | (___x << 4);       \
  69        ___x = ((___x & (u8)0xCCU) >> 2) | ((___x & (u8)0x33U) << 2);   \
  70        ___x = ((___x & (u8)0xAAU) >> 1) | ((___x & (u8)0x55U) << 1);   \
  71        ___x;                                                           \
  72})
  73
  74#define bitrev32(x) \
  75({                      \
  76        u32 __x = x;    \
  77        __builtin_constant_p(__x) ?     \
  78        __constant_bitrev32(__x) :                      \
  79        __bitrev32(__x);                                \
  80})
  81
  82#define bitrev16(x) \
  83({                      \
  84        u16 __x = x;    \
  85        __builtin_constant_p(__x) ?     \
  86        __constant_bitrev16(__x) :                      \
  87        __bitrev16(__x);                                \
  88 })
  89
  90#define bitrev8x4(x) \
  91({                      \
  92        u32 __x = x;    \
  93        __builtin_constant_p(__x) ?     \
  94        __constant_bitrev8x4(__x) :                     \
  95        __bitrev8x4(__x);                               \
  96 })
  97
  98#define bitrev8(x) \
  99({                      \
 100        u8 __x = x;     \
 101        __builtin_constant_p(__x) ?     \
 102        __constant_bitrev8(__x) :                       \
 103        __bitrev8(__x)  ;                       \
 104 })
 105#endif /* _LINUX_BITREV_H */
 106