diff options
Diffstat (limited to 'src/mscorlib/shared/System/Buffers/Utilities.cs')
-rw-r--r-- | src/mscorlib/shared/System/Buffers/Utilities.cs | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/mscorlib/shared/System/Buffers/Utilities.cs b/src/mscorlib/shared/System/Buffers/Utilities.cs new file mode 100644 index 0000000000..4f115fe9dd --- /dev/null +++ b/src/mscorlib/shared/System/Buffers/Utilities.cs @@ -0,0 +1,35 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. + +using System.Diagnostics; +using System.Runtime.CompilerServices; + +namespace System.Buffers +{ + internal static class Utilities + { + [MethodImpl(MethodImplOptions.AggressiveInlining)] + internal static int SelectBucketIndex(int bufferSize) + { + uint bitsRemaining = ((uint)bufferSize - 1) >> 4; + + int poolIndex = 0; + if (bitsRemaining > 0xFFFF) { bitsRemaining >>= 16; poolIndex = 16; } + if (bitsRemaining > 0xFF) { bitsRemaining >>= 8; poolIndex += 8; } + if (bitsRemaining > 0xF) { bitsRemaining >>= 4; poolIndex += 4; } + if (bitsRemaining > 0x3) { bitsRemaining >>= 2; poolIndex += 2; } + if (bitsRemaining > 0x1) { bitsRemaining >>= 1; poolIndex += 1; } + + return poolIndex + (int)bitsRemaining; + } + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + internal static int GetMaxSizeForBucket(int binIndex) + { + int maxSize = 16 << binIndex; + Debug.Assert(maxSize >= 0); + return maxSize; + } + } +} |