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| author | Jan Kotas <jkotas@microsoft.com> | 2018-10-15 21:39:18 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-10-15 21:39:18 -0700 |
| commit | d3ed7cb8da830657c376d4adb2862bc3c09cfef7 (patch) | |
| tree | 4760e9a64feb639c74bea3125dc9c5b815b63528 | |
| parent | 85ed652fef5f1dec7c532bd4963dd3cde0199211 (diff) | |
| download | coreclr-d3ed7cb8da830657c376d4adb2862bc3c09cfef7.tar.gz coreclr-d3ed7cb8da830657c376d4adb2862bc3c09cfef7.tar.bz2 coreclr-d3ed7cb8da830657c376d4adb2862bc3c09cfef7.zip | |
Optimize Span.GetPinnableReference (#20428)
* Optimize Span.GetPinnableReference
* CR feedback
| -rw-r--r-- | src/System.Private.CoreLib/shared/System/ReadOnlySpan.Fast.cs | 8 | ||||
| -rw-r--r-- | src/System.Private.CoreLib/shared/System/Span.Fast.cs | 8 |
2 files changed, 14 insertions, 2 deletions
diff --git a/src/System.Private.CoreLib/shared/System/ReadOnlySpan.Fast.cs b/src/System.Private.CoreLib/shared/System/ReadOnlySpan.Fast.cs index 4fb039a0fc..8ba8fd66b6 100644 --- a/src/System.Private.CoreLib/shared/System/ReadOnlySpan.Fast.cs +++ b/src/System.Private.CoreLib/shared/System/ReadOnlySpan.Fast.cs @@ -153,7 +153,13 @@ namespace System /// It can be used for pinning and is required to support the use of span within a fixed statement. /// </summary> [EditorBrowsable(EditorBrowsableState.Never)] - public unsafe ref readonly T GetPinnableReference() => ref (_length != 0) ? ref _pointer.Value : ref Unsafe.AsRef<T>(null); + public unsafe ref readonly T GetPinnableReference() + { + // Ensure that the native code has just one forward branch that is predicted-not-taken. + ref T ret = ref Unsafe.AsRef<T>(null); + if (_length != 0) ret = ref _pointer.Value; + return ref ret; + } /// <summary> /// Copies the contents of this read-only span into destination span. If the source diff --git a/src/System.Private.CoreLib/shared/System/Span.Fast.cs b/src/System.Private.CoreLib/shared/System/Span.Fast.cs index b3cfc8daff..3073592cd6 100644 --- a/src/System.Private.CoreLib/shared/System/Span.Fast.cs +++ b/src/System.Private.CoreLib/shared/System/Span.Fast.cs @@ -158,7 +158,13 @@ namespace System /// It can be used for pinning and is required to support the use of span within a fixed statement. /// </summary> [EditorBrowsable(EditorBrowsableState.Never)] - public unsafe ref T GetPinnableReference() => ref (_length != 0) ? ref _pointer.Value : ref Unsafe.AsRef<T>(null); + public unsafe ref T GetPinnableReference() + { + // Ensure that the native code has just one forward branch that is predicted-not-taken. + ref T ret = ref Unsafe.AsRef<T>(null); + if (_length != 0) ret = ref _pointer.Value; + return ref ret; + } /// <summary> /// Clears the contents of this span. |