text: /***********************************************************************
  **
  ** Implementation of the Skein block functions.
  **
  ** Source code author: Doug Whiting, 2008.
  **
  ** This algorithm and source code is released to the public domain.
  **
  ** Compile-time switches:
  **
  **  SKEIN_USE_ASM  -- set bits (256/512/1024) to select which
  **                    versions use ASM code for block processing
  **                    [default: use C for all block sizes]
  **
  ************************************************************************/
  
  #include <linux/string.h>
  #include "skein_base.h"
  #include "skein_block.h"
  
  #ifndef SKEIN_USE_ASM
  #define SKEIN_USE_ASM   (0) /* default is all C code (no ASM) */
  #endif
  
  #ifndef SKEIN_LOOP
  #define SKEIN_LOOP 001 /* default: unroll 256 and 512, but not 1024 */
  #endif
  
  #define BLK_BITS        (WCNT * 64) /* some useful definitions for code here */
  #define KW_TWK_BASE     (0)
  #define KW_KEY_BASE     (3)
  #define ks              (kw + KW_KEY_BASE)
  #define ts              (kw + KW_TWK_BASE)
  
  #ifdef SKEIN_DEBUG
  #define debug_save_tweak(ctx)       \
  {                                   \
  	ctx->h.tweak[0] = ts[0];    \
  	ctx->h.tweak[1] = ts[1];    \
  }
  #else
  #define debug_save_tweak(ctx)
  #endif
  
  #if !(SKEIN_USE_ASM & 256)
  #undef  RCNT
  #define RCNT (SKEIN_256_ROUNDS_TOTAL / 8)
  #ifdef SKEIN_LOOP /* configure how much to unroll the loop */
  #define SKEIN_UNROLL_256 (((SKEIN_LOOP) / 100) % 10)
  #else
  #define SKEIN_UNROLL_256 (0)
  #endif
  
  #if SKEIN_UNROLL_256
  #if (RCNT % SKEIN_UNROLL_256)
  #error "Invalid SKEIN_UNROLL_256" /* sanity check on unroll count */
  #endif
  #endif
  #define ROUND256(p0, p1, p2, p3, ROT, r_num) \
  do {                                         \
  	X##p0 += X##p1;                      \
  	X##p1 = rotl_64(X##p1, ROT##_0);     \
  	X##p1 ^= X##p0;                      \
  	X##p2 += X##p3;                      \
  	X##p3 = rotl_64(X##p3, ROT##_1);     \
  	X##p3 ^= X##p2;                      \
  } while (0)
  
  #if SKEIN_UNROLL_256 == 0
  #define R256(p0, p1, p2, p3, ROT, r_num) /* fully unrolled */ \
  do {                                                          \
  	ROUND256(p0, p1, p2, p3, ROT, r_num);                 \
  } while (0)
  
  #define I256(R)                                                           \
  do {                                                                      \
  	/* inject the key schedule value */                               \
  	X0   += ks[((R) + 1) % 5];                                        \
  	X1   += ks[((R) + 2) % 5] + ts[((R) + 1) % 3];                    \
  	X2   += ks[((R) + 3) % 5] + ts[((R) + 2) % 3];                    \
  	X3   += ks[((R) + 4) % 5] + (R) + 1;                              \
  } while (0)
  #else
  /* looping version */
  #define R256(p0, p1, p2, p3, ROT, r_num) ROUND256(p0, p1, p2, p3, ROT, r_num)
  
  #define I256(R) \
  do { \
  	/* inject the key schedule value */ \
  	X0 += ks[r + (R) + 0]; \
  	X1 += ks[r + (R) + 1] + ts[r + (R) + 0];                          \
  	X2 += ks[r + (R) + 2] + ts[r + (R) + 1];                          \
  	X3 += ks[r + (R) + 3] + r + (R);                                  \
  	/* rotate key schedule */                                         \
  	ks[r + (R) + 4] = ks[r + (R) - 1];                                \
  	ts[r + (R) + 2] = ts[r + (R) - 1];                                \
  } while (0)
  #endif
  #define R256_8_ROUNDS(R)                                 \
  do {                                                     \
  		R256(0, 1, 2, 3, R_256_0, 8 * (R) + 1);  \
  		R256(0, 3, 2, 1, R_256_1, 8 * (R) + 2);  \
  		R256(0, 1, 2, 3, R_256_2, 8 * (R) + 3);  \
  		R256(0, 3, 2, 1, R_256_3, 8 * (R) + 4);  \
  		I256(2 * (R));                           \
  		R256(0, 1, 2, 3, R_256_4, 8 * (R) + 5);  \
  		R256(0, 3, 2, 1, R_256_5, 8 * (R) + 6);  \
  		R256(0, 1, 2, 3, R_256_6, 8 * (R) + 7);  \
  		R256(0, 3, 2, 1, R_256_7, 8 * (R) + 8);  \
  		I256(2 * (R) + 1);                       \
  } while (0)
  
  #define R256_UNROLL_R(NN)                     \
  	((SKEIN_UNROLL_256 == 0 &&            \
  	SKEIN_256_ROUNDS_TOTAL / 8 > (NN)) || \
  	(SKEIN_UNROLL_256 > (NN)))
  
  #if  (SKEIN_UNROLL_256 > 14)
  #error  "need more unrolling in skein_256_process_block"
  #endif
  #endif
  
  #if !(SKEIN_USE_ASM & 512)
  #undef  RCNT
  #define RCNT  (SKEIN_512_ROUNDS_TOTAL/8)
  
  #ifdef SKEIN_LOOP /* configure how much to unroll the loop */
  #define SKEIN_UNROLL_512 (((SKEIN_LOOP)/10)%10)
  #else
  #define SKEIN_UNROLL_512 (0)
  #endif
  
  #if SKEIN_UNROLL_512
  #if (RCNT % SKEIN_UNROLL_512)
  #error "Invalid SKEIN_UNROLL_512" /* sanity check on unroll count */
  #endif
  #endif
  #define ROUND512(p0, p1, p2, p3, p4, p5, p6, p7, ROT, r_num) \
  do {                                                         \
  	X##p0 += X##p1;                                      \
  	X##p1 = rotl_64(X##p1, ROT##_0);                     \
  	X##p1 ^= X##p0;                                      \
  	X##p2 += X##p3;                                      \
  	X##p3 = rotl_64(X##p3, ROT##_1);                     \
  	X##p3 ^= X##p2;                                      \
  	X##p4 += X##p5;					     \
  	X##p5 = rotl_64(X##p5, ROT##_2);                     \
  	X##p5 ^= X##p4;                                      \
  	X##p6 += X##p7; X##p7 = rotl_64(X##p7, ROT##_3);     \
  	X##p7 ^= X##p6;                                      \
  } while (0)
  
  #if SKEIN_UNROLL_512 == 0
  #define R512(p0, p1, p2, p3, p4, p5, p6, p7, ROT, r_num) /* unrolled */ \
  do {                                                                    \
  	ROUND512(p0, p1, p2, p3, p4, p5, p6, p7, ROT, r_num);           \
  } while (0)
  
  #define I512(R)                                                           \
  do {                                                                      \
  	/* inject the key schedule value */                               \
  	X0   += ks[((R) + 1) % 9];                                        \
  	X1   += ks[((R) + 2) % 9];                                        \
  	X2   += ks[((R) + 3) % 9];                                        \
  	X3   += ks[((R) + 4) % 9];                                        \
  	X4   += ks[((R) + 5) % 9];                                        \
  	X5   += ks[((R) + 6) % 9] + ts[((R) + 1) % 3];                    \
  	X6   += ks[((R) + 7) % 9] + ts[((R) + 2) % 3];                    \
  	X7   += ks[((R) + 8) % 9] + (R) + 1;                              \
  } while (0)
  
  #else /* looping version */
  #define R512(p0, p1, p2, p3, p4, p5, p6, p7, ROT, r_num)                 \
  	ROUND512(p0, p1, p2, p3, p4, p5, p6, p7, ROT, r_num)             \
  
  #define I512(R)                                                           \
  do {                                                                      \
  	/* inject the key schedule value */                               \
  	X0   += ks[r + (R) + 0];                                          \
  	X1   += ks[r + (R) + 1];                                          \
  	X2   += ks[r + (R) + 2];                                          \
  	X3   += ks[r + (R) + 3];                                          \
  	X4   += ks[r + (R) + 4];                                          \
  	X5   += ks[r + (R) + 5] + ts[r + (R) + 0];                        \
  	X6   += ks[r + (R) + 6] + ts[r + (R) + 1];                        \
  	X7   += ks[r + (R) + 7] + r + (R);                                \
  	/* rotate key schedule */                                         \
  	ks[r + (R) + 8] = ks[r + (R) - 1];                                \
  	ts[r + (R) + 2] = ts[r + (R) - 1];                                \
  } while (0)
  #endif /* end of looped code definitions */
  #define R512_8_ROUNDS(R)  /* do 8 full rounds */                      \
  do {                                                                  \
  		R512(0, 1, 2, 3, 4, 5, 6, 7, R_512_0, 8 * (R) + 1);   \
  		R512(2, 1, 4, 7, 6, 5, 0, 3, R_512_1, 8 * (R) + 2);   \
  		R512(4, 1, 6, 3, 0, 5, 2, 7, R_512_2, 8 * (R) + 3);   \
  		R512(6, 1, 0, 7, 2, 5, 4, 3, R_512_3, 8 * (R) + 4);   \
  		I512(2 * (R));                              \
  		R512(0, 1, 2, 3, 4, 5, 6, 7, R_512_4, 8 * (R) + 5);   \
  		R512(2, 1, 4, 7, 6, 5, 0, 3, R_512_5, 8 * (R) + 6);   \
  		R512(4, 1, 6, 3, 0, 5, 2, 7, R_512_6, 8 * (R) + 7);   \
  		R512(6, 1, 0, 7, 2, 5, 4, 3, R_512_7, 8 * (R) + 8);   \
  		I512(2 * (R) + 1);        /* and key injection */     \
  } while (0)
  #define R512_UNROLL_R(NN)                             \
  		((SKEIN_UNROLL_512 == 0 &&            \
  		SKEIN_512_ROUNDS_TOTAL/8 > (NN)) ||   \
  		(SKEIN_UNROLL_512 > (NN)))
  
  #if  (SKEIN_UNROLL_512 > 14)
  #error  "need more unrolling in skein_512_process_block"
  #endif
  #endif
  
  #if !(SKEIN_USE_ASM & 1024)
  #undef  RCNT
  #define RCNT  (SKEIN_1024_ROUNDS_TOTAL/8)
  #ifdef SKEIN_LOOP /* configure how much to unroll the loop */
  #define SKEIN_UNROLL_1024 ((SKEIN_LOOP)%10)
  #else
  #define SKEIN_UNROLL_1024 (0)
  #endif
  
  #if (SKEIN_UNROLL_1024 != 0)
  #if (RCNT % SKEIN_UNROLL_1024)
  #error "Invalid SKEIN_UNROLL_1024" /* sanity check on unroll count */
  #endif
  #endif
  #define ROUND1024(p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, pA, pB, pC, pD, pE, \
  		  pF, ROT, r_num)                                             \
  do {                                                                          \
  	X##p0 += X##p1;                                                       \
  	X##p1 = rotl_64(X##p1, ROT##_0);                                      \
  	X##p1 ^= X##p0;                                                       \
  	X##p2 += X##p3;                                                       \
  	X##p3 = rotl_64(X##p3, ROT##_1);                                      \
  	X##p3 ^= X##p2;                                                       \
  	X##p4 += X##p5;                                                       \
  	X##p5 = rotl_64(X##p5, ROT##_2);                                      \
  	X##p5 ^= X##p4;                                                       \
  	X##p6 += X##p7;                                                       \
  	X##p7 = rotl_64(X##p7, ROT##_3);                                      \
  	X##p7 ^= X##p6;                                                       \
  	X##p8 += X##p9;                                                       \
  	X##p9 = rotl_64(X##p9, ROT##_4);                                      \
  	X##p9 ^= X##p8;                                                       \
  	X##pA += X##pB;                                                       \
  	X##pB = rotl_64(X##pB, ROT##_5);                                      \
  	X##pB ^= X##pA;                                                       \
  	X##pC += X##pD;                                                       \
  	X##pD = rotl_64(X##pD, ROT##_6);                                      \
  	X##pD ^= X##pC;                                                       \
  	X##pE += X##pF;                                                       \
  	X##pF = rotl_64(X##pF, ROT##_7);                                      \
  	X##pF ^= X##pE;                                                       \
  } while (0)
  
  #if SKEIN_UNROLL_1024 == 0
  #define R1024(p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, pA, pB, pC, pD, pE, pF, \
  	      ROT, rn)                                                        \
  	ROUND1024(p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, pA, pB, pC, pD, pE, \
  		  pF, ROT, rn)                                                \
  
  #define I1024(R)                                                          \
  do {                                                                      \
  	/* inject the key schedule value */                               \
  	X00 += ks[((R) + 1) % 17];                                        \
  	X01 += ks[((R) + 2) % 17];                                        \
  	X02 += ks[((R) + 3) % 17];                                        \
  	X03 += ks[((R) + 4) % 17];                                        \
  	X04 += ks[((R) + 5) % 17];                                        \
  	X05 += ks[((R) + 6) % 17];                                        \
  	X06 += ks[((R) + 7) % 17];                                        \
  	X07 += ks[((R) + 8) % 17];                                        \
  	X08 += ks[((R) + 9) % 17];                                        \
  	X09 += ks[((R) + 10) % 17];                                       \
  	X10 += ks[((R) + 11) % 17];                                       \
  	X11 += ks[((R) + 12) % 17];                                       \
  	X12 += ks[((R) + 13) % 17];                                       \
  	X13 += ks[((R) + 14) % 17] + ts[((R) + 1) % 3];                   \
  	X14 += ks[((R) + 15) % 17] + ts[((R) + 2) % 3];                   \
  	X15 += ks[((R) + 16) % 17] + (R) + 1;                             \
  } while (0)
  #else /* looping version */
  #define R1024(p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, pA, pB, pC, pD, pE, pF, \
  	      ROT, rn)                                                        \
  	ROUND1024(p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, pA, pB, pC, pD, pE, \
  		  pF, ROT, rn)                                                \
  
  #define I1024(R)                                                           \
  do {                                                                       \
  	/* inject the key schedule value */                                \
  	X00 += ks[r + (R) + 0];                                            \
  	X01 += ks[r + (R) + 1];                                            \
  	X02 += ks[r + (R) + 2];                                            \
  	X03 += ks[r + (R) + 3];                                            \
  	X04 += ks[r + (R) + 4];                                            \
  	X05 += ks[r + (R) + 5];                                            \
  	X06 += ks[r + (R) + 6];                                            \
  	X07 += ks[r + (R) + 7];                                            \
  	X08 += ks[r + (R) + 8];                                            \
  	X09 += ks[r + (R) + 9];                                            \
  	X10 += ks[r + (R) + 10];                                           \
  	X11 += ks[r + (R) + 11];                                           \
  	X12 += ks[r + (R) + 12];                                           \
  	X13 += ks[r + (R) + 13] + ts[r + (R) + 0];                         \
  	X14 += ks[r + (R) + 14] + ts[r + (R) + 1];                         \
  	X15 += ks[r + (R) + 15] + r + (R);                                 \
  	/* rotate key schedule */                                          \
  	ks[r + (R) + 16] = ks[r + (R) - 1];                                \
  	ts[r + (R) + 2] = ts[r + (R) - 1];                                 \
  } while (0)
  
  #endif
  #define R1024_8_ROUNDS(R)                                                     \
  do {                                                                          \
  	R1024(00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, \
  	      R1024_0, 8*(R) + 1);                                            \
  	R1024(00, 09, 02, 13, 06, 11, 04, 15, 10, 07, 12, 03, 14, 05, 08, 01, \
  	      R1024_1, 8*(R) + 2);                                            \
  	R1024(00, 07, 02, 05, 04, 03, 06, 01, 12, 15, 14, 13, 08, 11, 10, 09, \
  	      R1024_2, 8*(R) + 3);                                            \
  	R1024(00, 15, 02, 11, 06, 13, 04, 09, 14, 01, 08, 05, 10, 03, 12, 07, \
  	      R1024_3, 8*(R) + 4);                                            \
  	I1024(2*(R));                                                         \
  	R1024(00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, \
  	      R1024_4, 8*(R) + 5);                                            \
  	R1024(00, 09, 02, 13, 06, 11, 04, 15, 10, 07, 12, 03, 14, 05, 08, 01, \
  	      R1024_5, 8*(R) + 6);                                            \
  	R1024(00, 07, 02, 05, 04, 03, 06, 01, 12, 15, 14, 13, 08, 11, 10, 09, \
  	      R1024_6, 8*(R) + 7);                                            \
  	R1024(00, 15, 02, 11, 06, 13, 04, 09, 14, 01, 08, 05, 10, 03, 12, 07, \
  	      R1024_7, 8*(R) + 8);                                            \
  	I1024(2*(R)+1);                                                       \
  } while (0)
  
  #define R1024_UNROLL_R(NN)                              \
  		((SKEIN_UNROLL_1024 == 0 &&             \
  		SKEIN_1024_ROUNDS_TOTAL/8 > (NN)) ||  \
  		(SKEIN_UNROLL_1024 > (NN)))
  
  #if  (SKEIN_UNROLL_1024 > 14)
  #error  "need more unrolling in Skein_1024_Process_Block"
  #endif
  #endif
  
  /*****************************  SKEIN_256 ******************************/
  #if !(SKEIN_USE_ASM & 256)
  void skein_256_process_block(struct skein_256_ctx *ctx, const u8 *blk_ptr,
  			     size_t blk_cnt, size_t byte_cnt_add)
  { /* do it in C */
  	enum {
  		WCNT = SKEIN_256_STATE_WORDS
  	};
  	size_t r;
  #if SKEIN_UNROLL_256
  	/* key schedule: chaining vars + tweak + "rot"*/
  	u64  kw[WCNT+4+RCNT*2];
  #else
  	/* key schedule words : chaining vars + tweak */
  	u64  kw[WCNT+4];
  #endif
  	u64  X0, X1, X2, X3; /* local copy of context vars, for speed */
  	u64  w[WCNT]; /* local copy of input block */
  #ifdef SKEIN_DEBUG
  	const u64 *X_ptr[4]; /* use for debugging (help cc put Xn in regs) */
  
  	X_ptr[0] = &X0;
  	X_ptr[1] = &X1;
  	X_ptr[2] = &X2;
  	X_ptr[3] = &X3;
  #endif
  	skein_assert(blk_cnt != 0); /* never call with blk_cnt == 0! */
  	ts[0] = ctx->h.tweak[0];
  	ts[1] = ctx->h.tweak[1];
  	do  {
  		/*
  		 * this implementation only supports 2**64 input bytes
  		 * (no carry out here)
  		 */
  		ts[0] += byte_cnt_add; /* update processed length */
  
  		/* precompute the key schedule for this block */
  		ks[0] = ctx->x[0];
  		ks[1] = ctx->x[1];
  		ks[2] = ctx->x[2];
  		ks[3] = ctx->x[3];
  		ks[4] = ks[0] ^ ks[1] ^ ks[2] ^ ks[3] ^ SKEIN_KS_PARITY;
  
  		ts[2] = ts[0] ^ ts[1];
  
  		/* get input block in little-endian format */
  		skein_get64_lsb_first(w, blk_ptr, WCNT);
  		debug_save_tweak(ctx);
  
  		/* do the first full key injection */
  		X0 = w[0] + ks[0];
  		X1 = w[1] + ks[1] + ts[0];
  		X2 = w[2] + ks[2] + ts[1];
  		X3 = w[3] + ks[3];
  
  		blk_ptr += SKEIN_256_BLOCK_BYTES;
  
  		/* run the rounds */
  		for (r = 1;
  			r < (SKEIN_UNROLL_256 ? 2 * RCNT : 2);
  			r += (SKEIN_UNROLL_256 ? 2 * SKEIN_UNROLL_256 : 1)) {
  			R256_8_ROUNDS(0);
  #if   R256_UNROLL_R(1)
  			R256_8_ROUNDS(1);
  #endif
  #if   R256_UNROLL_R(2)
  			R256_8_ROUNDS(2);
  #endif
  #if   R256_UNROLL_R(3)
  			R256_8_ROUNDS(3);
  #endif
  #if   R256_UNROLL_R(4)
  			R256_8_ROUNDS(4);
  #endif
  #if   R256_UNROLL_R(5)
  			R256_8_ROUNDS(5);
  #endif
  #if   R256_UNROLL_R(6)
  			R256_8_ROUNDS(6);
  #endif
  #if   R256_UNROLL_R(7)
  			R256_8_ROUNDS(7);
  #endif
  #if   R256_UNROLL_R(8)
  			R256_8_ROUNDS(8);
  #endif
  #if   R256_UNROLL_R(9)
  			R256_8_ROUNDS(9);
  #endif
  #if   R256_UNROLL_R(10)
  			R256_8_ROUNDS(10);
  #endif
  #if   R256_UNROLL_R(11)
  			R256_8_ROUNDS(11);
  #endif
  #if   R256_UNROLL_R(12)
  			R256_8_ROUNDS(12);
  #endif
  #if   R256_UNROLL_R(13)
  			R256_8_ROUNDS(13);
  #endif
  #if   R256_UNROLL_R(14)
  			R256_8_ROUNDS(14);
  #endif
  		}
  		/* do the final "feedforward" xor, update context chaining */
  		ctx->x[0] = X0 ^ w[0];
  		ctx->x[1] = X1 ^ w[1];
  		ctx->x[2] = X2 ^ w[2];
  		ctx->x[3] = X3 ^ w[3];
  
  		ts[1] &= ~SKEIN_T1_FLAG_FIRST;
  	} while (--blk_cnt);
  	ctx->h.tweak[0] = ts[0];
  	ctx->h.tweak[1] = ts[1];
  }
  
  #if defined(SKEIN_CODE_SIZE) || defined(SKEIN_PERF)
  size_t skein_256_process_block_code_size(void)
  {
  	return ((u8 *) skein_256_process_block_code_size) -
  		((u8 *) skein_256_process_block);
  }
  unsigned int skein_256_unroll_cnt(void)
  {
  	return SKEIN_UNROLL_256;
  }
  #endif
  #endif
  
  /*****************************  SKEIN_512 ******************************/
  #if !(SKEIN_USE_ASM & 512)
  void skein_512_process_block(struct skein_512_ctx *ctx, const u8 *blk_ptr,
  			     size_t blk_cnt, size_t byte_cnt_add)
  { /* do it in C */
  	enum {
  		WCNT = SKEIN_512_STATE_WORDS
  	};
  	size_t  r;
  #if SKEIN_UNROLL_512
  	u64  kw[WCNT+4+RCNT*2]; /* key sched: chaining vars + tweak + "rot"*/
  #else
  	u64  kw[WCNT+4]; /* key schedule words : chaining vars + tweak */
  #endif
  	u64  X0, X1, X2, X3, X4, X5, X6, X7; /* local copies, for speed */
  	u64  w[WCNT]; /* local copy of input block */
  #ifdef SKEIN_DEBUG
  	const u64 *X_ptr[8]; /* use for debugging (help cc put Xn in regs) */
  
  	X_ptr[0] = &X0;
  	X_ptr[1] = &X1;
  	X_ptr[2] = &X2;
  	X_ptr[3] = &X3;
  	X_ptr[4] = &X4;
  	X_ptr[5] = &X5;
  	X_ptr[6] = &X6;
  	X_ptr[7] = &X7;
  #endif
  
  	skein_assert(blk_cnt != 0); /* never call with blk_cnt == 0! */
  	ts[0] = ctx->h.tweak[0];
  	ts[1] = ctx->h.tweak[1];
  	do  {
  		/*
  		 * this implementation only supports 2**64 input bytes
  		 * (no carry out here)
  		 */
  		ts[0] += byte_cnt_add; /* update processed length */
  
  		/* precompute the key schedule for this block */
  		ks[0] = ctx->x[0];
  		ks[1] = ctx->x[1];
  		ks[2] = ctx->x[2];
  		ks[3] = ctx->x[3];
  		ks[4] = ctx->x[4];
  		ks[5] = ctx->x[5];
  		ks[6] = ctx->x[6];
  		ks[7] = ctx->x[7];
  		ks[8] = ks[0] ^ ks[1] ^ ks[2] ^ ks[3] ^
  			ks[4] ^ ks[5] ^ ks[6] ^ ks[7] ^ SKEIN_KS_PARITY;
  
  		ts[2] = ts[0] ^ ts[1];
  
  		/* get input block in little-endian format */
  		skein_get64_lsb_first(w, blk_ptr, WCNT);
  		debug_save_tweak(ctx);
  
  		/* do the first full key injection */
  		X0 = w[0] + ks[0];
  		X1 = w[1] + ks[1];
  		X2 = w[2] + ks[2];
  		X3 = w[3] + ks[3];
  		X4 = w[4] + ks[4];
  		X5 = w[5] + ks[5] + ts[0];
  		X6 = w[6] + ks[6] + ts[1];
  		X7 = w[7] + ks[7];
  
  		blk_ptr += SKEIN_512_BLOCK_BYTES;
  
  		/* run the rounds */
  		for (r = 1;
  			r < (SKEIN_UNROLL_512 ? 2 * RCNT : 2);
  			r += (SKEIN_UNROLL_512 ? 2 * SKEIN_UNROLL_512 : 1)) {
  
  			R512_8_ROUNDS(0);
  
  #if   R512_UNROLL_R(1)
  			R512_8_ROUNDS(1);
  #endif
  #if   R512_UNROLL_R(2)
  			R512_8_ROUNDS(2);
  #endif
  #if   R512_UNROLL_R(3)
  			R512_8_ROUNDS(3);
  #endif
  #if   R512_UNROLL_R(4)
  			R512_8_ROUNDS(4);
  #endif
  #if   R512_UNROLL_R(5)
  			R512_8_ROUNDS(5);
  #endif
  #if   R512_UNROLL_R(6)
  			R512_8_ROUNDS(6);
  #endif
  #if   R512_UNROLL_R(7)
  			R512_8_ROUNDS(7);
  #endif
  #if   R512_UNROLL_R(8)
  			R512_8_ROUNDS(8);
  #endif
  #if   R512_UNROLL_R(9)
  			R512_8_ROUNDS(9);
  #endif
  #if   R512_UNROLL_R(10)
  			R512_8_ROUNDS(10);
  #endif
  #if   R512_UNROLL_R(11)
  			R512_8_ROUNDS(11);
  #endif
  #if   R512_UNROLL_R(12)
  			R512_8_ROUNDS(12);
  #endif
  #if   R512_UNROLL_R(13)
  			R512_8_ROUNDS(13);
  #endif
  #if   R512_UNROLL_R(14)
  			R512_8_ROUNDS(14);
  #endif
  		}
  
  		/* do the final "feedforward" xor, update context chaining */
  		ctx->x[0] = X0 ^ w[0];
  		ctx->x[1] = X1 ^ w[1];
  		ctx->x[2] = X2 ^ w[2];
  		ctx->x[3] = X3 ^ w[3];
  		ctx->x[4] = X4 ^ w[4];
  		ctx->x[5] = X5 ^ w[5];
  		ctx->x[6] = X6 ^ w[6];
  		ctx->x[7] = X7 ^ w[7];
  
  		ts[1] &= ~SKEIN_T1_FLAG_FIRST;
  	} while (--blk_cnt);
  	ctx->h.tweak[0] = ts[0];
  	ctx->h.tweak[1] = ts[1];
  }
  
  #if defined(SKEIN_CODE_SIZE) || defined(SKEIN_PERF)
  size_t skein_512_process_block_code_size(void)
  {
  	return ((u8 *) skein_512_process_block_code_size) -
  		((u8 *) skein_512_process_block);
  }
  unsigned int skein_512_unroll_cnt(void)
  {
  	return SKEIN_UNROLL_512;
  }
  #endif
  #endif
  
  /*****************************  SKEIN_1024 ******************************/
  #if !(SKEIN_USE_ASM & 1024)
  void skein_1024_process_block(struct skein_1024_ctx *ctx, const u8 *blk_ptr,
  			      size_t blk_cnt, size_t byte_cnt_add)
  { /* do it in C, always looping (unrolled is bigger AND slower!) */
  	enum {
  		WCNT = SKEIN_1024_STATE_WORDS
  	};
  	size_t  r;
  #if (SKEIN_UNROLL_1024 != 0)
  	u64  kw[WCNT+4+RCNT*2]; /* key sched: chaining vars + tweak + "rot" */
  #else
  	u64  kw[WCNT+4]; /* key schedule words : chaining vars + tweak */
  #endif
  
  	/* local copy of vars, for speed */
  	u64  X00, X01, X02, X03, X04, X05, X06, X07,
  	     X08, X09, X10, X11, X12, X13, X14, X15;
  	u64  w[WCNT]; /* local copy of input block */
  
  	skein_assert(blk_cnt != 0); /* never call with blk_cnt == 0! */
  	ts[0] = ctx->h.tweak[0];
  	ts[1] = ctx->h.tweak[1];
  	do  {
  		/*
  		 * this implementation only supports 2**64 input bytes
  		 * (no carry out here)
  		 */
  		ts[0] += byte_cnt_add; /* update processed length */
  
  		/* precompute the key schedule for this block */
  		ks[0]  = ctx->x[0];
  		ks[1]  = ctx->x[1];
  		ks[2]  = ctx->x[2];
  		ks[3]  = ctx->x[3];
  		ks[4]  = ctx->x[4];
  		ks[5]  = ctx->x[5];
  		ks[6]  = ctx->x[6];
  		ks[7]  = ctx->x[7];
  		ks[8]  = ctx->x[8];
  		ks[9]  = ctx->x[9];
  		ks[10] = ctx->x[10];
  		ks[11] = ctx->x[11];
  		ks[12] = ctx->x[12];
  		ks[13] = ctx->x[13];
  		ks[14] = ctx->x[14];
  		ks[15] = ctx->x[15];
  		ks[16] =  ks[0] ^ ks[1] ^ ks[2] ^ ks[3] ^
  			  ks[4] ^ ks[5] ^ ks[6] ^ ks[7] ^
  			  ks[8] ^ ks[9] ^ ks[10] ^ ks[11] ^
  			  ks[12] ^ ks[13] ^ ks[14] ^ ks[15] ^ SKEIN_KS_PARITY;
  
  		ts[2] = ts[0] ^ ts[1];
  
  		/* get input block in little-endian format */
  		skein_get64_lsb_first(w, blk_ptr, WCNT);
  		debug_save_tweak(ctx);
  
  		/* do the first full key injection */
  		X00 = w[0] + ks[0];
  		X01 = w[1] + ks[1];
  		X02 = w[2] + ks[2];
  		X03 = w[3] + ks[3];
  		X04 = w[4] + ks[4];
  		X05 = w[5] + ks[5];
  		X06 = w[6] + ks[6];
  		X07 = w[7] + ks[7];
  		X08 = w[8] + ks[8];
  		X09 = w[9] + ks[9];
  		X10 = w[10] + ks[10];
  		X11 = w[11] + ks[11];
  		X12 = w[12] + ks[12];
  		X13 = w[13] + ks[13] + ts[0];
  		X14 = w[14] + ks[14] + ts[1];
  		X15 = w[15] + ks[15];
  
  		for (r = 1;
  			r < (SKEIN_UNROLL_1024 ? 2 * RCNT : 2);
  			r += (SKEIN_UNROLL_1024 ? 2 * SKEIN_UNROLL_1024 : 1)) {
  			R1024_8_ROUNDS(0);
  #if   R1024_UNROLL_R(1)
  			R1024_8_ROUNDS(1);
  #endif
  #if   R1024_UNROLL_R(2)
  			R1024_8_ROUNDS(2);
  #endif
  #if   R1024_UNROLL_R(3)
  			R1024_8_ROUNDS(3);
  #endif
  #if   R1024_UNROLL_R(4)
  			R1024_8_ROUNDS(4);
  #endif
  #if   R1024_UNROLL_R(5)
  			R1024_8_ROUNDS(5);
  #endif
  #if   R1024_UNROLL_R(6)
  			R1024_8_ROUNDS(6);
  #endif
  #if   R1024_UNROLL_R(7)
  			R1024_8_ROUNDS(7);
  #endif
  #if   R1024_UNROLL_R(8)
  			R1024_8_ROUNDS(8);
  #endif
  #if   R1024_UNROLL_R(9)
  			R1024_8_ROUNDS(9);
  #endif
  #if   R1024_UNROLL_R(10)
  			R1024_8_ROUNDS(10);
  #endif
  #if   R1024_UNROLL_R(11)
  			R1024_8_ROUNDS(11);
  #endif
  #if   R1024_UNROLL_R(12)
  			R1024_8_ROUNDS(12);
  #endif
  #if   R1024_UNROLL_R(13)
  			R1024_8_ROUNDS(13);
  #endif
  #if   R1024_UNROLL_R(14)
  			R1024_8_ROUNDS(14);
  #endif
  		}
  		/* do the final "feedforward" xor, update context chaining */
  
  		ctx->x[0] = X00 ^ w[0];
  		ctx->x[1] = X01 ^ w[1];
  		ctx->x[2] = X02 ^ w[2];
  		ctx->x[3] = X03 ^ w[3];
  		ctx->x[4] = X04 ^ w[4];
  		ctx->x[5] = X05 ^ w[5];
  		ctx->x[6] = X06 ^ w[6];
  		ctx->x[7] = X07 ^ w[7];
  		ctx->x[8] = X08 ^ w[8];
  		ctx->x[9] = X09 ^ w[9];
  		ctx->x[10] = X10 ^ w[10];
  		ctx->x[11] = X11 ^ w[11];
  		ctx->x[12] = X12 ^ w[12];
  		ctx->x[13] = X13 ^ w[13];
  		ctx->x[14] = X14 ^ w[14];
  		ctx->x[15] = X15 ^ w[15];
  
  		ts[1] &= ~SKEIN_T1_FLAG_FIRST;
  		blk_ptr += SKEIN_1024_BLOCK_BYTES;
  	} while (--blk_cnt);
  	ctx->h.tweak[0] = ts[0];
  	ctx->h.tweak[1] = ts[1];
  }
  
  #if defined(SKEIN_CODE_SIZE) || defined(SKEIN_PERF)
  size_t skein_1024_process_block_code_size(void)
  {
  	return ((u8 *) skein_1024_process_block_code_size) -
  		((u8 *) skein_1024_process_block);
  }
  unsigned int skein_1024_unroll_cnt(void)
  {
  	return SKEIN_UNROLL_1024;
  }
  #endif
  #endif
  