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src/SpookyV2.h  view on Meta::CPAN

    // all the pieces concatenated into one message.
    //
    void Final(
        uint64 *hash1,    // out only: first 64 bits of hash value.
        uint64 *hash2);   // out only: second 64 bits of hash value.

    //
    // left rotate a 64-bit value by k bytes
    //
    static INLINE uint64 Rot64(uint64 x, int k)
    {
        return (x << k) | (x >> (64 - k));
    }

    //
    // This is used if the input is 96 bytes long or longer.
    //
    // The internal state is fully overwritten every 96 bytes.
    // Every input bit appears to cause at least 128 bits of entropy
    // before 96 other bytes are combined, when run forward or backward
    //   For every input bit,
    //   Two inputs differing in just that input bit
    //   Where "differ" means xor or subtraction
    //   And the base value is random
    //   When run forward or backwards one Mix
    // I tried 3 pairs of each; they all differed by at least 212 bits.
    //
    static INLINE void Mix(
        const uint64 *data, 
        uint64 &s0, uint64 &s1, uint64 &s2, uint64 &s3,
        uint64 &s4, uint64 &s5, uint64 &s6, uint64 &s7,
        uint64 &s8, uint64 &s9, uint64 &s10,uint64 &s11)
    {
      s0 += data[0];    s2 ^= s10;    s11 ^= s0;    s0 = Rot64(s0,11);    s11 += s1;
      s1 += data[1];    s3 ^= s11;    s0 ^= s1;    s1 = Rot64(s1,32);    s0 += s2;
      s2 += data[2];    s4 ^= s0;    s1 ^= s2;    s2 = Rot64(s2,43);    s1 += s3;
      s3 += data[3];    s5 ^= s1;    s2 ^= s3;    s3 = Rot64(s3,31);    s2 += s4;
      s4 += data[4];    s6 ^= s2;    s3 ^= s4;    s4 = Rot64(s4,17);    s3 += s5;
      s5 += data[5];    s7 ^= s3;    s4 ^= s5;    s5 = Rot64(s5,28);    s4 += s6;
      s6 += data[6];    s8 ^= s4;    s5 ^= s6;    s6 = Rot64(s6,39);    s5 += s7;
      s7 += data[7];    s9 ^= s5;    s6 ^= s7;    s7 = Rot64(s7,57);    s6 += s8;
      s8 += data[8];    s10 ^= s6;    s7 ^= s8;    s8 = Rot64(s8,55);    s7 += s9;
      s9 += data[9];    s11 ^= s7;    s8 ^= s9;    s9 = Rot64(s9,54);    s8 += s10;
      s10 += data[10];    s0 ^= s8;    s9 ^= s10;    s10 = Rot64(s10,22);    s9 += s11;
      s11 += data[11];    s1 ^= s9;    s10 ^= s11;    s11 = Rot64(s11,46);    s10 += s0;
    }

    //
    // Mix all 12 inputs together so that h0, h1 are a hash of them all.
    //
    // For two inputs differing in just the input bits
    // Where "differ" means xor or subtraction
    // And the base value is random, or a counting value starting at that bit
    // The final result will have each bit of h0, h1 flip
    // For every input bit,
    // with probability 50 +- .3%
    // For every pair of input bits,
    // with probability 50 +- 3%
    //
    // This does not rely on the last Mix() call having already mixed some.
    // Two iterations was almost good enough for a 64-bit result, but a
    // 128-bit result is reported, so End() does three iterations.
    //
    static INLINE void EndPartial(
        uint64 &h0, uint64 &h1, uint64 &h2, uint64 &h3,
        uint64 &h4, uint64 &h5, uint64 &h6, uint64 &h7, 
        uint64 &h8, uint64 &h9, uint64 &h10,uint64 &h11)
    {
        h11+= h1;    h2 ^= h11;   h1 = Rot64(h1,44);
        h0 += h2;    h3 ^= h0;    h2 = Rot64(h2,15);
        h1 += h3;    h4 ^= h1;    h3 = Rot64(h3,34);
        h2 += h4;    h5 ^= h2;    h4 = Rot64(h4,21);
        h3 += h5;    h6 ^= h3;    h5 = Rot64(h5,38);
        h4 += h6;    h7 ^= h4;    h6 = Rot64(h6,33);
        h5 += h7;    h8 ^= h5;    h7 = Rot64(h7,10);
        h6 += h8;    h9 ^= h6;    h8 = Rot64(h8,13);
        h7 += h9;    h10^= h7;    h9 = Rot64(h9,38);
        h8 += h10;   h11^= h8;    h10= Rot64(h10,53);
        h9 += h11;   h0 ^= h9;    h11= Rot64(h11,42);
        h10+= h0;    h1 ^= h10;   h0 = Rot64(h0,54);
    }

    static INLINE void End(
        const uint64 *data, 
        uint64 &h0, uint64 &h1, uint64 &h2, uint64 &h3,
        uint64 &h4, uint64 &h5, uint64 &h6, uint64 &h7, 
        uint64 &h8, uint64 &h9, uint64 &h10,uint64 &h11)
    {
        h0 += data[0];   h1 += data[1];   h2 += data[2];   h3 += data[3];
        h4 += data[4];   h5 += data[5];   h6 += data[6];   h7 += data[7];
        h8 += data[8];   h9 += data[9];   h10 += data[10]; h11 += data[11];
        EndPartial(h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
        EndPartial(h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
        EndPartial(h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
    }

    //
    // The goal is for each bit of the input to expand into 128 bits of 
    //   apparent entropy before it is fully overwritten.
    // n trials both set and cleared at least m bits of h0 h1 h2 h3
    //   n: 2   m: 29
    //   n: 3   m: 46
    //   n: 4   m: 57
    //   n: 5   m: 107
    //   n: 6   m: 146
    //   n: 7   m: 152
    // when run forwards or backwards
    // for all 1-bit and 2-bit diffs
    // with diffs defined by either xor or subtraction
    // with a base of all zeros plus a counter, or plus another bit, or random
    //
    static INLINE void ShortMix(uint64 &h0, uint64 &h1, uint64 &h2, uint64 &h3)
    {
        h2 = Rot64(h2,50);  h2 += h3;  h0 ^= h2;
        h3 = Rot64(h3,52);  h3 += h0;  h1 ^= h3;
        h0 = Rot64(h0,30);  h0 += h1;  h2 ^= h0;
        h1 = Rot64(h1,41);  h1 += h2;  h3 ^= h1;
        h2 = Rot64(h2,54);  h2 += h3;  h0 ^= h2;
        h3 = Rot64(h3,48);  h3 += h0;  h1 ^= h3;
        h0 = Rot64(h0,38);  h0 += h1;  h2 ^= h0;
        h1 = Rot64(h1,37);  h1 += h2;  h3 ^= h1;
        h2 = Rot64(h2,62);  h2 += h3;  h0 ^= h2;