static inline void xor_salsa8(uint32_t B[16], const uint32_t Bx[16])
{
uint32_t x00,x01,x02,x03,x04,x05,x06,x07,x08,x09,x10,x11,x12,x13,x14,x15;
int i;
x00 = (B[ 0] ^= Bx[ 0]);
x01 = (B[ 1] ^= Bx[ 1]);
x02 = (B[ 2] ^= Bx[ 2]);
x03 = (B[ 3] ^= Bx[ 3]);
x04 = (B[ 4] ^= Bx[ 4]);
x05 = (B[ 5] ^= Bx[ 5]);
x06 = (B[ 6] ^= Bx[ 6]);
x07 = (B[ 7] ^= Bx[ 7]);
x08 = (B[ 8] ^= Bx[ 8]);
x09 = (B[ 9] ^= Bx[ 9]);
x10 = (B[10] ^= Bx[10]);
x11 = (B[11] ^= Bx[11]);
x12 = (B[12] ^= Bx[12]);
x13 = (B[13] ^= Bx[13]);
x14 = (B[14] ^= Bx[14]);
x15 = (B[15] ^= Bx[15]);
for (i = 0; i < 8; i += 2) {
#define R(a, b) (((a) << (b)) | ((a) >> (32 - (b))))
/* Operate on columns. */
x04 ^= R(x00+x12, 7); x09 ^= R(x05+x01, 7);
x14 ^= R(x10+x06, 7); x03 ^= R(x15+x11, 7);
x08 ^= R(x04+x00, 9); x13 ^= R(x09+x05, 9);
x02 ^= R(x14+x10, 9); x07 ^= R(x03+x15, 9);
x12 ^= R(x08+x04,13); x01 ^= R(x13+x09,13);
x06 ^= R(x02+x14,13); x11 ^= R(x07+x03,13);
x00 ^= R(x12+x08,18); x05 ^= R(x01+x13,18);
x10 ^= R(x06+x02,18); x15 ^= R(x11+x07,18);
/* Operate on rows. */
x01 ^= R(x00+x03, 7); x06 ^= R(x05+x04, 7);
x11 ^= R(x10+x09, 7); x12 ^= R(x15+x14, 7);
x02 ^= R(x01+x00, 9); x07 ^= R(x06+x05, 9);
x08 ^= R(x11+x10, 9); x13 ^= R(x12+x15, 9);
x03 ^= R(x02+x01,13); x04 ^= R(x07+x06,13);
x09 ^= R(x08+x11,13); x14 ^= R(x13+x12,13);
x00 ^= R(x03+x02,18); x05 ^= R(x04+x07,18);
x10 ^= R(x09+x08,18); x15 ^= R(x14+x13,18);
#undef R
}
B[ 0] += x00;
B[ 1] += x01;
B[ 2] += x02;
B[ 3] += x03;
B[ 4] += x04;
B[ 5] += x05;
B[ 6] += x06;
B[ 7] += x07;
B[ 8] += x08;
B[ 9] += x09;
B[10] += x10;
B[11] += x11;
B[12] += x12;
B[13] += x13;
B[14] += x14;
B[15] += x15;
}
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