[API Implementation]: Expose general purpose Crc32 APIs

src/libraries/Common/src/System/Numerics/Crc32ReflectedTable.cs

@@ -0,0 +1,34 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Numerics
+{
+    internal static class Crc32ReflectedTable
+    {
+        internal static uint[] Generate(uint reflectedPolynomial)
+        {
+            uint[] table = new uint[256];
+
+            for (int i = 0; i < 256; i++)
+            {
+                uint val = (uint)i;
+
+                for (int j = 0; j < 8; j++)
+                {
+                    if ((val & 0b0000_0001) == 0)
+                    {
+                        val >>= 1;
+                    }
+                    else
+                    {
+                        val = (val >> 1) ^ reflectedPolynomial;
+                    }
+                }
+
+                table[i] = val;
+            }
+
+            return table;
+        }
+    }
+}

src/libraries/System.IO.Hashing/src/System.IO.Hashing.csproj

@@ -20,6 +20,9 @@ System.IO.Hashing.XxHash32</PackageDescription>
     <Compile Include="System\IO\Hashing\XxHash64.cs" />
     <Compile Include="System\IO\Hashing\XxHash64.State.cs" />
     <Compile Include="System\IO\Hashing\NonCryptographicHashAlgorithm.cs" />
+    <Compile Include="$(CommonPath)System\Numerics\Crc32ReflectedTable.cs">
+      <Link>Common\System\Numerics\Crc32ReflectedTable.cs</Link>
+    </Compile>
     <Compile Include="System\IO\Hashing\BitOperations.cs"
              Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
   </ItemGroup>

src/libraries/System.IO.Hashing/src/System/IO/Hashing/Crc32.Table.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Numerics;
+
 namespace System.IO.Hashing
 {
     public sealed partial class Crc32 : NonCryptographicHashAlgorithm
@@ -9,32 +11,6 @@ public sealed partial class Crc32 : NonCryptographicHashAlgorithm
         // While this implementation is based on the standard CRC-32 polynomial,
         // x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x1 + x0,
         // this version uses reflected bit ordering, so 0x04C11DB7 becomes 0xEDB88320
-        private static readonly uint[] s_crcLookup = GenerateReflectedTable(0xEDB88320u);
-
-        private static uint[] GenerateReflectedTable(uint reflectedPolynomial)
-        {
-            uint[] table = new uint[256];
-
-            for (int i = 0; i < 256; i++)
-            {
-                uint val = (uint)i;
-
-                for (int j = 0; j < 8; j++)
-                {
-                    if ((val & 0b0000_0001) == 0)
-                    {
-                        val >>= 1;
-                    }
-                    else
-                    {
-                        val = (val >> 1) ^ reflectedPolynomial;
-                    }
-                }
-
-                table[i] = val;
-            }
-
-            return table;
-        }
+        private static readonly uint[] s_crcLookup = Crc32ReflectedTable.Generate(0xEDB88320u);
     }
 }

src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems

@@ -1262,6 +1262,9 @@
     <Compile Include="$(CommonPath)System\NotImplemented.cs">
       <Link>Common\System\NotImplemented.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)System\Numerics\Crc32ReflectedTable.cs">
+      <Link>Common\System\Numerics\Crc32ReflectedTable.cs</Link>
+    </Compile>
     <Compile Include="$(CommonPath)System\Obsoletions.cs">
       <Link>Common\System\Obsoletions.cs</Link>
     </Compile>

src/libraries/System.Private.CoreLib/src/System/Numerics/BitOperations.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Buffers.Binary;
+using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Runtime.Intrinsics;
@@ -51,7 +53,7 @@ public static class BitOperations
         /// <param name="value">The value.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         [CLSCompliant(false)]
-        public static bool IsPow2(uint value) => (value & (value - 1)) == 0 && value != 0 ;
+        public static bool IsPow2(uint value) => (value & (value - 1)) == 0 && value != 0;
 
         /// <summary>
         /// Evaluate whether a given integral value is a power of 2.
@@ -730,6 +732,164 @@ public static nuint RotateRight(nuint value, int offset)
 #endif
         }
 
+        /// <summary>
+        /// Accumulates the CRC (Cyclic redundancy check) checksum.
+        /// </summary>
+        /// <param name="crc">The base value to calculate checksum on</param>
+        /// <param name="data">The data for which to compute the checksum</param>
+        /// <returns>The CRC-checksum</returns>
+        [CLSCompliant(false)]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static uint Crc32C(uint crc, byte data)
+        {
+            if (Sse42.IsSupported)
+            {
+                return Sse42.Crc32(crc, data);
+            }
+
+            if (Crc32.IsSupported)
+            {
+                return Crc32.ComputeCrc32C(crc, data);
+            }
+
+            return Crc32Fallback.Crc32C(crc, data);
+        }
+
+        /// <summary>
+        /// Accumulates the CRC (Cyclic redundancy check) checksum.
+        /// </summary>
+        /// <param name="crc">The base value to calculate checksum on</param>
+        /// <param name="data">The data for which to compute the checksum</param>
+        /// <returns>The CRC-checksum</returns>
+        [CLSCompliant(false)]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static uint Crc32C(uint crc, ushort data)
+        {
+            if (Sse42.IsSupported)
+            {
+                return Sse42.Crc32(crc, data);
+            }
+
+            if (Crc32.IsSupported)
+            {
+                return Crc32.ComputeCrc32C(crc, data);
+            }
+
+            return Crc32Fallback.Crc32C(crc, data);
+        }
+
+        /// <summary>
+        /// Accumulates the CRC (Cyclic redundancy check) checksum.
+        /// </summary>
+        /// <param name="crc">The base value to calculate checksum on</param>
+        /// <param name="data">The data for which to compute the checksum</param>
+        /// <returns>The CRC-checksum</returns>
+        [CLSCompliant(false)]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static uint Crc32C(uint crc, uint data)
+        {
+            if (Sse42.IsSupported)
+            {
+                return Sse42.Crc32(crc, data);
+            }
+
+            if (Crc32.IsSupported)
+            {
+                return Crc32.ComputeCrc32C(crc, data);
+            }
+
+            return Crc32Fallback.Crc32C(crc, data);
+        }
+
+        /// <summary>
+        /// Accumulates the CRC (Cyclic redundancy check) checksum.
+        /// </summary>
+        /// <param name="crc">The base value to calculate checksum on</param>
+        /// <param name="data">The data for which to compute the checksum</param>
+        /// <returns>The CRC-checksum</returns>
+        [CLSCompliant(false)]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static uint Crc32C(uint crc, ulong data)
+        {
+            if (Sse42.X64.IsSupported)
+            {
+                // This intrinsic returns a 64-bit register with the upper 32-bits set to 0.
+                return (uint)Sse42.X64.Crc32(crc, data);
+            }
+
+            if (Sse42.IsSupported)
+            {
+                uint result = Sse42.Crc32(crc, (uint)(data));
+                return Sse42.Crc32(result, (uint)(data >> 32));
+            }
+
+            if (Crc32.Arm64.IsSupported)
+            {
+                return Crc32.Arm64.ComputeCrc32C(crc, data);
+            }
+
+            return Crc32Fallback.Crc32C(crc, data);
+        }
+
+        private static class Crc32Fallback
+        {
+            // Pre-computed CRC-32 transition table.
+            // While this implementation is based on the Castagnoli CRC-32 polynomial (CRC-32C),
+            // x32 + x28 + x27 + x26 + x25 + x23 + x22 + x20 + x19 + x18 + x14 + x13 + x11 + x10 + x9 + x8 + x6 + x0,
+            // this version uses reflected bit ordering, so 0x1EDC6F41 becomes 0x82F63B78u
+            private static readonly uint[] s_crcTable = Crc32ReflectedTable.Generate(0x82F63B78u);
+
+            internal static uint Crc32C(uint crc, byte data)
+            {
+                ref uint lookupTable = ref MemoryMarshal.GetArrayDataReference(s_crcTable);
+                crc = Unsafe.Add(ref lookupTable, (nint)(byte)(crc ^ data)) ^ (crc >> 8);
+
+                return crc;
+            }
+
+            internal static uint Crc32C(uint crc, ushort data)
+            {
+                ref uint lookupTable = ref MemoryMarshal.GetArrayDataReference(s_crcTable);
+
+                crc = Unsafe.Add(ref lookupTable, (nint)(byte)(crc ^ (byte)data)) ^ (crc >> 8);
+                data >>= 8;
+                crc = Unsafe.Add(ref lookupTable, (nint)(byte)(crc ^ data)) ^ (crc >> 8);
+
+                return crc;
+            }
+
+            internal static uint Crc32C(uint crc, uint data)
+            {
+                ref uint lookupTable = ref MemoryMarshal.GetArrayDataReference(s_crcTable);
+                return Crc32CCore(ref lookupTable, crc, data);
+            }
+
+            internal static uint Crc32C(uint crc, ulong data)
+            {
+                ref uint lookupTable = ref MemoryMarshal.GetArrayDataReference(s_crcTable);
+
+                crc = Crc32CCore(ref lookupTable, crc, (uint)data);
+                data >>= 32;
+                crc = Crc32CCore(ref lookupTable, crc, (uint)data);
+
+                return crc;
+            }
+
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            private static uint Crc32CCore(ref uint lookupTable, uint crc, uint data)
+            {
+                crc = Unsafe.Add(ref lookupTable, (nint)(byte)(crc ^ (byte)data)) ^ (crc >> 8);
+                data >>= 8;
+                crc = Unsafe.Add(ref lookupTable, (nint)(byte)(crc ^ (byte)data)) ^ (crc >> 8);
+                data >>= 8;
+                crc = Unsafe.Add(ref lookupTable, (nint)(byte)(crc ^ (byte)data)) ^ (crc >> 8);
+                data >>= 8;
+                crc = Unsafe.Add(ref lookupTable, (nint)(byte)(crc ^ data)) ^ (crc >> 8);
+
+                return crc;
+            }
+        }
+
         /// <summary>
         /// Reset the lowest significant bit in the given value
         /// </summary>

src/libraries/System.Runtime.Extensions/tests/System/Numerics/BitOperationsTests.cs

@@ -887,5 +887,49 @@ public static void BitOps_RoundUpToPow2_nuint_64(ulong value, ulong expected)
         {
             Assert.Equal(expected, BitOperations.RoundUpToPowerOf2((nuint) value));
         }
+
+        [Theory]
+        [InlineData(0, 0, 0)]
+        [InlineData(0, 120, 4215344322)]
+        [InlineData(0, byte.MaxValue, 2910671697)]
+        [InlineData(123, byte.MaxValue, 1164749927)]
+        public static void BitOps_Crc32C_byte(uint crc, byte data, uint expected)
+        {
+            uint obtained = BitOperations.Crc32C(crc, data);
+            Assert.Equal(expected, obtained);
+        }
+
+        [Theory]
+        [InlineData(0, 0, 0)]
+        [InlineData(0, 120, 575477567)]
+        [InlineData(0, ushort.MaxValue, 245266386)]
+        [InlineData(123, ushort.MaxValue, 406112372)]
+        public static void BitOps_Crc32C_ushort(uint crc, ushort data, uint expected)
+        {
+            uint obtained = BitOperations.Crc32C(crc, data);
+            Assert.Equal(expected, obtained);
+        }
+
+        [Theory]
+        [InlineData(0, 0, 0)]
+        [InlineData(0, 120, 1671666103)]
+        [InlineData(0, uint.MaxValue, 3080238136)]
+        [InlineData(123, uint.MaxValue, 3055133878)]
+        public static void BitOps_Crc32C_uint(uint crc, uint data, uint expected)
+        {
+            uint obtained = BitOperations.Crc32C(crc, data);
+            Assert.Equal(expected, obtained);
+        }
+
+        [Theory]
+        [InlineData(0, 0, 0)]
+        [InlineData(0, 120, 3511526341)]
+        [InlineData(0, ulong.MaxValue, 3293575501)]
+        [InlineData(123, ulong.MaxValue, 3460750817)]
+        public static void BitOps_Crc32C_ulong(uint crc, ulong data, uint expected)
+        {
+            uint obtained = BitOperations.Crc32C(crc, data);
+            Assert.Equal(expected, obtained);
+        }
     }
 }

src/libraries/System.Runtime/ref/System.Runtime.cs

@@ -10217,6 +10217,14 @@ public static partial class BitOperations
         public static int TrailingZeroCount(ulong value) { throw null; }
         [System.CLSCompliantAttribute(false)]
         public static int TrailingZeroCount(nuint value) { throw null; }
+        [System.CLSCompliantAttribute(false)]
+        public static uint Crc32C(uint crc, byte data) { throw null; }
+        [System.CLSCompliantAttribute(false)]
+        public static uint Crc32C(uint crc, ushort data) { throw null; }
+        [System.CLSCompliantAttribute(false)]
+        public static uint Crc32C(uint crc, uint data) { throw null; }
+        [System.CLSCompliantAttribute(false)]
+        public static uint Crc32C(uint crc, ulong data) { throw null; }
     }
     public partial interface IAdditionOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IAdditionOperators<TSelf, TOther, TResult>?
     {