diff options
Diffstat (limited to 'crypto/src/math/raw/Interleave.cs')
| -rw-r--r-- | crypto/src/math/raw/Interleave.cs | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/crypto/src/math/raw/Interleave.cs b/crypto/src/math/raw/Interleave.cs index d21840644..591ba3f15 100644 --- a/crypto/src/math/raw/Interleave.cs +++ b/crypto/src/math/raw/Interleave.cs @@ -6,6 +6,7 @@ namespace Org.BouncyCastle.Math.Raw { private const ulong M32 = 0x55555555UL; private const ulong M64 = 0x5555555555555555UL; + private const ulong M64R = 0xAAAAAAAAAAAAAAAAUL; /* * This expands 8 bit indices into 16 bit contents (high bit 14), by inserting 0s between bits. @@ -92,6 +93,65 @@ namespace Org.BouncyCastle.Math.Raw z[zOff + 1] = (x >> 1) & M64; } + internal static void Expand64To128Rev(ulong x, ulong[] z, int zOff) + { + // "shuffle" low half to even bits and high half to odd bits + ulong t; + t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); + t = (x ^ (x >> 8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t << 8)); + t = (x ^ (x >> 4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t << 4)); + t = (x ^ (x >> 2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t << 2)); + t = (x ^ (x >> 1)) & 0x2222222222222222UL; x ^= (t ^ (t << 1)); + + z[zOff] = (x ) & M64R; + z[zOff + 1] = (x << 1) & M64R; + } + + internal static uint Shuffle(uint x) + { + // "shuffle" low half to even bits and high half to odd bits + uint t; + t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); + t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); + t = (x ^ (x >> 2)) & 0x0C0C0C0CU; x ^= (t ^ (t << 2)); + t = (x ^ (x >> 1)) & 0x22222222U; x ^= (t ^ (t << 1)); + return x; + } + + internal static ulong Shuffle(ulong x) + { + // "shuffle" low half to even bits and high half to odd bits + ulong t; + t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); + t = (x ^ (x >> 8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t << 8)); + t = (x ^ (x >> 4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t << 4)); + t = (x ^ (x >> 2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t << 2)); + t = (x ^ (x >> 1)) & 0x2222222222222222UL; x ^= (t ^ (t << 1)); + return x; + } + + internal static uint Shuffle2(uint x) + { + // "shuffle" (twice) low half to even bits and high half to odd bits + uint t; + t = (x ^ (x >> 7)) & 0x00AA00AAU; x ^= (t ^ (t << 7)); + t = (x ^ (x >> 14)) & 0x0000CCCCU; x ^= (t ^ (t << 14)); + t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); + t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); + return x; + } + + internal static uint Unshuffle(uint x) + { + // "unshuffle" even bits to low half and odd bits to high half + uint t; + t = (x ^ (x >> 1)) & 0x22222222U; x ^= (t ^ (t << 1)); + t = (x ^ (x >> 2)) & 0x0C0C0C0CU; x ^= (t ^ (t << 2)); + t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); + t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); + return x; + } + internal static ulong Unshuffle(ulong x) { // "unshuffle" even bits to low half and odd bits to high half @@ -103,5 +163,16 @@ namespace Org.BouncyCastle.Math.Raw t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); return x; } + + internal static uint Unshuffle2(uint x) + { + // "unshuffle" (twice) even bits to low half and odd bits to high half + uint t; + t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); + t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); + t = (x ^ (x >> 14)) & 0x0000CCCCU; x ^= (t ^ (t << 14)); + t = (x ^ (x >> 7)) & 0x00AA00AAU; x ^= (t ^ (t << 7)); + return x; + } } } |