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| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2022-11-20 14:41:31 +0700 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2022-11-20 14:41:31 +0700 |
| commit | fc3fa1f342ac19fbe7ee27b3a20a6a246ef0a1e9 (patch) | |
| tree | aa9da31e1414c355521356e6e7a84225813191f3 /crypto/src/math | |
| parent | Factor Codec out of EdDSA (diff) | |
| download | BouncyCastle.NET-ed25519-fc3fa1f342ac19fbe7ee27b3a20a6a246ef0a1e9.tar.xz | |
Intrinsics for shuffles
Diffstat (limited to 'crypto/src/math')
| -rw-r--r-- | crypto/src/math/raw/Interleave.cs | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/crypto/src/math/raw/Interleave.cs b/crypto/src/math/raw/Interleave.cs index 3e994a43c..196f7c9b5 100644 --- a/crypto/src/math/raw/Interleave.cs +++ b/crypto/src/math/raw/Interleave.cs @@ -156,6 +156,14 @@ namespace Org.BouncyCastle.Math.Raw internal static uint Shuffle(uint x) { +#if NETCOREAPP3_0_OR_GREATER + if (Bmi2.IsSupported) + { + return Bmi2.ParallelBitDeposit(x >> 16, 0xAAAAAAAAU) + | Bmi2.ParallelBitDeposit(x , 0x55555555U); + } +#endif + // "shuffle" low half to even bits and high half to odd bits x = Bits.BitPermuteStep(x, 0x0000FF00U, 8); x = Bits.BitPermuteStep(x, 0x00F000F0U, 4); @@ -166,6 +174,14 @@ namespace Org.BouncyCastle.Math.Raw internal static ulong Shuffle(ulong x) { +#if NETCOREAPP3_0_OR_GREATER + if (Bmi2.IsSupported) + { + return Bmi2.X64.ParallelBitDeposit(x >> 32, 0xAAAAAAAAAAAAAAAAUL) + | Bmi2.X64.ParallelBitDeposit(x , 0x5555555555555555UL); + } +#endif + // "shuffle" low half to even bits and high half to odd bits x = Bits.BitPermuteStep(x, 0x00000000FFFF0000UL, 16); x = Bits.BitPermuteStep(x, 0x0000FF000000FF00UL, 8); @@ -177,6 +193,16 @@ namespace Org.BouncyCastle.Math.Raw internal static uint Shuffle2(uint x) { +#if NETCOREAPP3_0_OR_GREATER + if (Bmi2.IsSupported) + { + return Bmi2.ParallelBitDeposit(x >> 24, 0x88888888U) + | Bmi2.ParallelBitDeposit(x >> 16, 0x44444444U) + | Bmi2.ParallelBitDeposit(x >> 8, 0x22222222U) + | Bmi2.ParallelBitDeposit(x , 0x11111111U); + } +#endif + // "shuffle" (twice) low half to even bits and high half to odd bits x = Bits.BitPermuteStep(x, 0x00AA00AAU, 7); x = Bits.BitPermuteStep(x, 0x0000CCCCU, 14); @@ -187,6 +213,14 @@ namespace Org.BouncyCastle.Math.Raw internal static uint Unshuffle(uint x) { +#if NETCOREAPP3_0_OR_GREATER + if (Bmi2.IsSupported) + { + return Bmi2.ParallelBitExtract(x, 0xAAAAAAAAU) << 16 + | Bmi2.ParallelBitExtract(x, 0x55555555U); + } +#endif + // "unshuffle" even bits to low half and odd bits to high half x = Bits.BitPermuteStep(x, 0x22222222U, 1); x = Bits.BitPermuteStep(x, 0x0C0C0C0CU, 2); @@ -249,6 +283,16 @@ namespace Org.BouncyCastle.Math.Raw internal static uint Unshuffle2(uint x) { +#if NETCOREAPP3_0_OR_GREATER + if (Bmi2.IsSupported) + { + return Bmi2.ParallelBitExtract(x, 0x88888888U) << 24 + | Bmi2.ParallelBitExtract(x, 0x44444444U) << 16 + | Bmi2.ParallelBitExtract(x, 0x22222222U) << 8 + | Bmi2.ParallelBitExtract(x, 0x11111111U); + } +#endif + // "unshuffle" (twice) even bits to low half and odd bits to high half x = Bits.BitPermuteStep(x, 0x0000FF00U, 8); x = Bits.BitPermuteStep(x, 0x00F000F0U, 4); |