按位逻辑运算 012345678-＞02461357

淡淡的烟草味﹌ 2023-07-15 09:07 30阅读 0赞

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## 按位逻辑运算： ##

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*  按位与运算符（&）  
    运算规则：只有两个数的二进制同时为1，结果才为1，否则为0。（负数按补码形式参加按位与运算）  
    即 0 & 0= 0 ，0 & 1= 0，1 & 0= 0， 1 & 1= 1。
    
        任何值 & 1，为任何数（不变）； & 0，为0。
 *  按位或运算符（|）  
    运算规则：参加运算的两个数只要两个数中的一个为1，结果就为1。  
    即 0 | 0= 0 , 1 | 0= 1 ， 0 | 1= 1 , 1 | 1= 1 。
    
        任何值 | 0，为任何数（不变）；|1,为1。
 *  异或运算符（^）  
    运算规则：参加运算的两个数，如果两个相应位为“异”（值不同），则该位结果为1，否则为0。  
    即 0 ^ 0=0 ， 0 ^ 1= 1 ， 1 ^ 0= 1 ， 1 ^ 1= 0 。
    
        任何值 ^ 0，为任何数（不变）；^ 1,为取反。

**x | (x >> 1)与lo ^ (lo >> 1)区别？**

*  ^能保持原始值（不变或取反） ；
 *  |1,为1，丢失了原始信息。

## 实际应用1 ##

//奇数位为1，以1位为单位提取奇偶位
    0xAAAAAAAA = 10101010101010101010101010101010
    0x55555555 = 01010101010101010101010101010101
    //以“2位”为单位提取奇偶位
    0xCCCCCCCC = 11001100110011001100110011001100
    0x33333333 = 00110011001100110011001100110011
    //以“8位”为单位提取奇偶位
    0xF0F0F0F0 = 11110000111100001111000011110000
    0x0F0F0F0F = 00001111000011110000111100001111
    //以“16位”为单位提取奇偶位
    0xFFFF0000 = 11111111111111110000000000000000
    0x0000FFFF = 00000000000000001111111111111111

code

D:\data\vs\AEADASCON\ascon_opt32\opt32
    #define COMPRESS_LONG(x) {\ x &= 0x55555555;\ x = (x | (x >> 1)) & 0x33333333;\ x = (x | (x >> 2)) & 0x0f0f0f0f;\ x = (x | (x >> 4)) & 0x00ff00ff;\ x = (x | (x >> 8)) & 0x0000ffff;\ }

https://editor.csdn.net/md/?articleId=104864566  
将u32分解成两个u16，在实现过程中使用了u32类型数据。

## 实际应用2 ##

D:\\data\\20200206\\LWC\\asconLWC\\ascon-c-master\\crypto\_aead\\ascon128v12\\bi32\_lowreg\*\*

//endian.h
    #ifndef ENDIAN_H_
    #define ENDIAN_H_
    #if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
    // macros for big endian machines
    #define U64BIG(x) (x)
    #define U32BIG(x) (x)
    #define U16BIG(x) (x)
    #elif defined(_MSC_VER) || \ (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
    // macros for little endian machines
    #define U64BIG(x) \ ((((x) & 0x00000000000000FFULL) << 56) | (((x) & 0x000000000000FF00ULL) << 40) | \ (((x) & 0x0000000000FF0000ULL) << 24) | (((x) & 0x00000000FF000000ULL) << 8) | \ (((x) & 0x000000FF00000000ULL) >> 8) | (((x) & 0x0000FF0000000000ULL) >> 24) | \ (((x) & 0x00FF000000000000ULL) >> 40) | (((x) & 0xFF00000000000000ULL) >> 56))
    #define U32BIG(x) \ ((((x) & 0x000000FF) << 24) | (((x) & 0x0000FF00) << 8) | \ (((x) & 0x00FF0000) >> 8) | (((x) & 0xFF000000) >> 24))
    #define U16BIG(x) \ ((((x) & 0x00FF) << 8) | (((x) & 0xFF00) >> 8))
      #else
    #error "ascon byte order macros not defined in endian.h"
    #endif
    #endif // ENDIAN_H_
    
    
    
    typedef struct { 
      u32 e;
      u32 o;
    } u32_2;
    
    
    
    // Credit to Henry S. Warren, Hacker's Delight, Addison-Wesley, 2002
    #define to_bit_interleaving(out, in) \ do { \ u32 hi = (in) >> 32; \ u32 lo = (u32)(in); \ u32 r0, r1; \ r0 = (lo ^ (lo >> 1)) & 0x22222222, lo ^= r0 ^ (r0 << 1); \ r0 = (lo ^ (lo >> 2)) & 0x0C0C0C0C, lo ^= r0 ^ (r0 << 2); \ r0 = (lo ^ (lo >> 4)) & 0x00F000F0, lo ^= r0 ^ (r0 << 4); \ r0 = (lo ^ (lo >> 8)) & 0x0000FF00, lo ^= r0 ^ (r0 << 8); \ r1 = (hi ^ (hi >> 1)) & 0x22222222, hi ^= r1 ^ (r1 << 1); \ r1 = (hi ^ (hi >> 2)) & 0x0C0C0C0C, hi ^= r1 ^ (r1 << 2); \ r1 = (hi ^ (hi >> 4)) & 0x00F000F0, hi ^= r1 ^ (r1 << 4); \ r1 = (hi ^ (hi >> 8)) & 0x0000FF00, hi ^= r1 ^ (r1 << 8); \ (out).e = (lo & 0x0000FFFF) | (hi << 16); \ (out).o = (lo >> 16) | (hi & 0xFFFF0000); \ } while (0)
    
    // Credit to Henry S. Warren, Hacker's Delight, Addison-Wesley, 2002
    #define from_bit_interleaving(out, in) \ do { \ u32 lo = ((in).e & 0x0000FFFF) | ((in).o << 16); \ u32 hi = ((in).e >> 16) | ((in).o & 0xFFFF0000); \ u32 r0, r1; \ r0 = (lo ^ (lo >> 8)) & 0x0000FF00, lo ^= r0 ^ (r0 << 8); \ r0 = (lo ^ (lo >> 4)) & 0x00F000F0, lo ^= r0 ^ (r0 << 4); \ r0 = (lo ^ (lo >> 2)) & 0x0C0C0C0C, lo ^= r0 ^ (r0 << 2); \ r0 = (lo ^ (lo >> 1)) & 0x22222222, lo ^= r0 ^ (r0 << 1); \ r1 = (hi ^ (hi >> 8)) & 0x0000FF00, hi ^= r1 ^ (r1 << 8); \ r1 = (hi ^ (hi >> 4)) & 0x00F000F0, hi ^= r1 ^ (r1 << 4); \ r1 = (hi ^ (hi >> 2)) & 0x0C0C0C0C, hi ^= r1 ^ (r1 << 2); \ r1 = (hi ^ (hi >> 1)) & 0x22222222, hi ^= r1 ^ (r1 << 1); \ out = (u64)hi << 32 | lo; \ } while (0)
    
    
      void main(){ 
      unsigned char* k;
      u32_2 K0;
      //输入参数为u8以及u32类型数据
      to_bit_interleaving(K0, U64BIG(*(u64*)k));
    }

code

//使用u32数据类型，建奇数偶数下标分开。
        u32 lo = (u32)(in);                                       \
        u32 r0, r1;                                               \
                               
        r0 = (lo ^ (lo >> 1)) & 0x22222222, lo ^= r0 ^ (r0 << 1); \
        r0 = (lo ^ (lo >> 2)) & 0x0C0C0C0C, lo ^= r0 ^ (r0 << 2); \
        r0 = (lo ^ (lo >> 4)) & 0x00F000F0, lo ^= r0 ^ (r0 << 4); \
        r0 = (lo ^ (lo >> 8)) & 0x0000FF00, lo ^= r0 ^ (r0 << 8); \

result：

![在这里插入图片描述][20200316111535596.png]

代码分解：

0x22222222=00100010001000100010001000100010
    r0 = (lo ^ (lo >> 1)) & 0x22222222, lo ^= r0 ^ (r0 << 1);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MDIxNjk1_size_16_color_FFFFFF_t_70]

0x0C0C0C0C=00001100000011000000110000001100
    r0 = (lo ^ (lo >> 2)) & 0x0C0C0C0C, lo ^= r0 ^ (r0 << 2);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MDIxNjk1_size_16_color_FFFFFF_t_70 1]

0x00F000F0=00000000111100000000000011110000
    r0 = (lo ^ (lo >> 4)) & 0x00F000F0, lo ^= r0 ^ (r0 << 4);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MDIxNjk1_size_16_color_FFFFFF_t_70 2]

0x0000FF00=00000000000000001111111100000000
    r0 = (lo ^ (lo >> 8)) & 0x0000FF00, lo ^= r0 ^ (r0 << 8);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MDIxNjk1_size_16_color_FFFFFF_t_70 3]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MDIxNjk1_size_16_color_FFFFFF_t_70 4]

[20200316111535596.png]: /images/20230528/1e530b59b6e14c3d86e89611f3edf570.png
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MDIxNjk1_size_16_color_FFFFFF_t_70 1]: /images/20230528/07b2b366bc4248e4b56d543a5ebd0379.png
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