skein.h

//...
/*****************************************************************                                  
** Skein block function constants (shared across Ref and Opt code)                                  
******************************************************************/                                 
enum                                                                                                
    {                                                                                               
        /* Skein_256 round rotation constants */                                                    
    R_256_0_0=14, R_256_0_1=16,                                                                     
    R_256_1_0=52, R_256_1_1=57,                                                                     
    R_256_2_0=23, R_256_2_1=40,                                                                     
    R_256_3_0= 5, R_256_3_1=37,                                                                     
    R_256_4_0=25, R_256_4_1=33,                                                                     
    R_256_5_0=46, R_256_5_1=12,                                                                     
    R_256_6_0=58, R_256_6_1=22,                                                                     
    R_256_7_0=32, R_256_7_1=32,                                                                     
                                                                                                    
        /* Skein_512 round rotation constants */                                                    
    R_512_0_0=46, R_512_0_1=36, R_512_0_2=19, R_512_0_3=37,                                         
    R_512_1_0=33, R_512_1_1=27, R_512_1_2=14, R_512_1_3=42,                                         
    R_512_2_0=17, R_512_2_1=49, R_512_2_2=36, R_512_2_3=39,                                         
    R_512_3_0=44, R_512_3_1= 9, R_512_3_2=54, R_512_3_3=56,                                         
    R_512_4_0=39, R_512_4_1=30, R_512_4_2=34, R_512_4_3=24,                                         
    R_512_5_0=13, R_512_5_1=50, R_512_5_2=10, R_512_5_3=17,                                         
    R_512_6_0=25, R_512_6_1=29, R_512_6_2=39, R_512_6_3=43,                                         
    R_512_7_0= 8, R_512_7_1=35, R_512_7_2=56, R_512_7_3=22,                                         
                                                                                                    
        /* Skein1024 round rotation constants */                                                    
    R1024_0_0=24, R1024_0_1=13, R1024_0_2= 8, R1024_0_3=47, R1024_0_4= 8, R1024_0_5=17, R1024_0_6=22, R1024_0_7=37,
    R1024_1_0=38, R1024_1_1=19, R1024_1_2=10, R1024_1_3=55, R1024_1_4=49, R1024_1_5=18, R1024_1_6=23, R1024_1_7=52,
    R1024_2_0=33, R1024_2_1= 4, R1024_2_2=51, R1024_2_3=13, R1024_2_4=34, R1024_2_5=41, R1024_2_6=59, R1024_2_7=17,
    R1024_3_0= 5, R1024_3_1=20, R1024_3_2=48, R1024_3_3=41, R1024_3_4=47, R1024_3_5=28, R1024_3_6=16, R1024_3_7=25,
    R1024_4_0=41, R1024_4_1= 9, R1024_4_2=37, R1024_4_3=31, R1024_4_4=12, R1024_4_5=47, R1024_4_6=44, R1024_4_7=30,
    R1024_5_0=16, R1024_5_1=34, R1024_5_2=56, R1024_5_3=51, R1024_5_4= 4, R1024_5_5=53, R1024_5_6=42, R1024_5_7=41,
    R1024_6_0=31, R1024_6_1=44, R1024_6_2=47, R1024_6_3=46, R1024_6_4=19, R1024_6_5=42, R1024_6_6=44, R1024_6_7=25,
    R1024_7_0= 9, R1024_7_1=48, R1024_7_2=35, R1024_7_3=52, R1024_7_4=23, R1024_7_5=31, R1024_7_6=37, R1024_7_7=20
    };                                                                                              
//...

skein_block.c

//...
for (r=1;r <= SKEIN_256_ROUNDS_TOTAL/8; r++)
    { /* unroll 8 rounds */
    X[0] += X[1]; X[1] = RotL_64(X[1],R_256_0_0); X[1] ^= X[0];
    X[2] += X[3]; X[3] = RotL_64(X[3],R_256_0_1); X[3] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r-7,X);

    X[0] += X[3]; X[3] = RotL_64(X[3],R_256_1_0); X[3] ^= X[0];
    X[2] += X[1]; X[1] = RotL_64(X[1],R_256_1_1); X[1] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r-6,X);

    X[0] += X[1]; X[1] = RotL_64(X[1],R_256_2_0); X[1] ^= X[0];
    X[2] += X[3]; X[3] = RotL_64(X[3],R_256_2_1); X[3] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r-5,X);

    X[0] += X[3]; X[3] = RotL_64(X[3],R_256_3_0); X[3] ^= X[0];
    X[2] += X[1]; X[1] = RotL_64(X[1],R_256_3_1); X[1] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r-4,X);
    InjectKey(2*r-1);

    X[0] += X[1]; X[1] = RotL_64(X[1],R_256_4_0); X[1] ^= X[0];
    X[2] += X[3]; X[3] = RotL_64(X[3],R_256_4_1); X[3] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r-3,X);

    X[0] += X[3]; X[3] = RotL_64(X[3],R_256_5_0); X[3] ^= X[0];
    X[2] += X[1]; X[1] = RotL_64(X[1],R_256_5_1); X[1] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r-2,X);

    X[0] += X[1]; X[1] = RotL_64(X[1],R_256_6_0); X[1] ^= X[0];
    X[2] += X[3]; X[3] = RotL_64(X[3],R_256_6_1); X[3] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r-1,X);

    X[0] += X[3]; X[3] = RotL_64(X[3],R_256_7_0); X[3] ^= X[0];
    X[2] += X[1]; X[1] = RotL_64(X[1],R_256_7_1); X[1] ^= X[2];  Skein_Show_Round(BLK_BITS,&ctx->h,8*r  ,X);
    InjectKey(2*r);
    }
//...