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| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2021-06-01 14:11:19 +0700 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2021-06-01 14:11:19 +0700 |
| commit | 0f23f1ffd16324dfb4045822ba6d39b32c775989 (patch) | |
| tree | b756cb4759fc0dc7acd0c03ef894fc5e195b4199 /crypto/src/util/Integers.cs | |
| parent | Correction (diff) | |
| download | BouncyCastle.NET-ed25519-0f23f1ffd16324dfb4045822ba6d39b32c775989.tar.xz | |
NTZ for 0 should be 32/64 resp.
- add tests for NLZ, NTZ - round out methods for Longs class
Diffstat (limited to 'crypto/src/util/Integers.cs')
| -rw-r--r-- | crypto/src/util/Integers.cs | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/crypto/src/util/Integers.cs b/crypto/src/util/Integers.cs index 11045d9e3..cc46862bd 100644 --- a/crypto/src/util/Integers.cs +++ b/crypto/src/util/Integers.cs @@ -10,9 +10,8 @@ namespace Org.BouncyCastle.Utilities public const int NumBytes = 4; private static readonly byte[] DeBruijnTZ = { - 0x00, 0x01, 0x02, 0x18, 0x03, 0x13, 0x06, 0x19, 0x16, 0x04, 0x14, 0x0A, - 0x10, 0x07, 0x0C, 0x1A, 0x1F, 0x17, 0x12, 0x05, 0x15, 0x09, 0x0F, 0x0B, - 0x1E, 0x11, 0x08, 0x0E, 0x1D, 0x0D, 0x1C, 0x1B }; + 0x1F, 0x00, 0x1B, 0x01, 0x1C, 0x0D, 0x17, 0x02, 0x1D, 0x15, 0x13, 0x0E, 0x18, 0x10, 0x03, 0x07, + 0x1E, 0x1A, 0x0C, 0x16, 0x14, 0x12, 0x0F, 0x06, 0x19, 0x0B, 0x11, 0x05, 0x0A, 0x04, 0x09, 0x08 }; public static int NumberOfLeadingZeros(int i) { @@ -31,7 +30,9 @@ namespace Org.BouncyCastle.Utilities public static int NumberOfTrailingZeros(int i) { - return DeBruijnTZ[(uint)((i & -i) * 0x04D7651F) >> 27]; + int n = DeBruijnTZ[(uint)((i & -i) * 0x0EF96A62) >> 27]; + int m = (((i & 0xFFFF) | (int)((uint)i >> 16)) - 1) >> 31; + return n - m; } public static int Reverse(int i) |