Optimize RotateLeft (#2542)

src/neo/Cryptography/Helper.cs

@@ -46,7 +46,7 @@ public static byte[] RIPEMD160(this ReadOnlySpan<byte> value)
  /// <returns>The computed hash code.</returns>
  public static uint Murmur32(this byte[] value, uint seed)
  {
- using Murmur3 murmur = new(seed);
+ using Murmur32 murmur = new(seed);
  return BinaryPrimitives.ReadUInt32LittleEndian(murmur.ComputeHash(value));
  }
 

src/neo/Cryptography/Murmur128.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Buffers.Binary;
+using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Security.Cryptography;
 
@@ -45,19 +46,19 @@ protected override void HashCore(byte[] array, int ibStart, int cbSize)
  {
  ulong k1 = BinaryPrimitives.ReadUInt64LittleEndian(array.AsSpan(i));
  k1 *= c1;
- k1 = RotateLeft(k1, r1);
+ k1 = BitOperations.RotateLeft(k1, r1);
  k1 *= c2;
  H1 ^= k1;
- H1 = RotateLeft(H1, 27);
+ H1 = BitOperations.RotateLeft(H1, 27);
  H1 += H2;
  H1 = H1 * m + n1;
 
  ulong k2 = BinaryPrimitives.ReadUInt64LittleEndian(array.AsSpan(i + 8));
  k2 *= c2;
- k2 = RotateLeft(k2, r2);
+ k2 = BitOperations.RotateLeft(k2, r2);
  k2 *= c1;
  H2 ^= k2;
- H2 = RotateLeft(H2, 31);
+ H2 = BitOperations.RotateLeft(H2, 31);
  H2 += H1;
  H2 = H2 * m + n2;
  }
@@ -84,8 +85,8 @@ protected override void HashCore(byte[] array, int ibStart, int cbSize)
  case 1: remainingBytesL ^= (ulong)array[alignedLength] << 0; break;
  }
 
- H2 ^= RotateLeft(remainingBytesH * c2, r2) * c1;
- H1 ^= RotateLeft(remainingBytesL * c1, r1) * c2;
+ H2 ^= BitOperations.RotateLeft(remainingBytesH * c2, r2) * c1;
+ H1 ^= BitOperations.RotateLeft(remainingBytesL * c1, r1) * c2;
  }
  }
 
@@ -118,12 +119,6 @@ public override void Initialize()
  length = 0;
  }
 
- [MethodImpl(MethodImplOptions.AggressiveInlining)]
- private static ulong RotateLeft(ulong x, byte n)
- {
- return (x << n) | (x >> (64 - n));
- }
-
  [MethodImpl(MethodImplOptions.AggressiveInlining)]
  private static ulong FMix(ulong h)
  {

src/neo/Cryptography/Murmur3.cs → src/neo/Cryptography/Murmur32.cs

@@ -1,14 +1,14 @@
 using System;
 using System.Buffers.Binary;
-using System.Runtime.CompilerServices;
+using System.Numerics;
 using System.Security.Cryptography;
 
 namespace Neo.Cryptography
 {
  /// <summary>
  /// Computes the murmur hash for the input data.
  /// </summary>
- public sealed class Murmur3 : HashAlgorithm
+ public sealed class Murmur32 : HashAlgorithm
  {
  private const uint c1 = 0xcc9e2d51;
  private const uint c2 = 0x1b873593;
@@ -24,10 +24,10 @@ public sealed class Murmur3 : HashAlgorithm
  public override int HashSize => 32;
 
  /// <summary>
- /// Initializes a new instance of the <see cref="Murmur3"/> class with the specified seed.
+ /// Initializes a new instance of the <see cref="Murmur32"/> class with the specified seed.
  /// </summary>
  /// <param name="seed">The seed to be used.</param>
- public Murmur3(uint seed)
+ public Murmur32(uint seed)
  {
  this.seed = seed;
  Initialize();
@@ -42,10 +42,10 @@ protected override void HashCore(byte[] array, int ibStart, int cbSize)
  {
  uint k = BinaryPrimitives.ReadUInt32LittleEndian(array.AsSpan(i));
  k *= c1;
- k = RotateLeft(k, r1);
+ k = BitOperations.RotateLeft(k, r1);
  k *= c2;
  hash ^= k;
- hash = RotateLeft(hash, r2);
+ hash = BitOperations.RotateLeft(hash, r2);
  hash = hash * m + n;
  }
  if (remainder > 0)
@@ -58,7 +58,7 @@ protected override void HashCore(byte[] array, int ibStart, int cbSize)
  case 1: remainingBytes ^= array[alignedLength]; break;
  }
  remainingBytes *= c1;
- remainingBytes = RotateLeft(remainingBytes, r1);
+ remainingBytes = BitOperations.RotateLeft(remainingBytes, r1);
  remainingBytes *= c2;
  hash ^= remainingBytes;
  }
@@ -83,11 +83,5 @@ public override void Initialize()
  hash = seed;
  length = 0;
  }
-
- [MethodImpl(MethodImplOptions.AggressiveInlining)]
- private static uint RotateLeft(uint x, byte n)
- {
- return (x << n) | (x >> (32 - n));
- }
  }
 }

tests/neo.UnitTests/Cryptography/UT_Murmur3.cs → tests/neo.UnitTests/Cryptography/UT_Murmur32.cs

@@ -5,12 +5,12 @@
 namespace Neo.UnitTests.Cryptography
 {
  [TestClass]
- public class UT_Murmur3
+ public class UT_Murmur32
  {
  [TestMethod]
  public void TestGetHashSize()
  {
- Murmur3 murmur3 = new Murmur3(1);
+ Murmur32 murmur3 = new Murmur32(1);
  murmur3.HashSize.Should().Be(32);
  }