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Faster Span #16222

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Faster Span #16222

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a0d1c09
Slim Span Exception code
benaadams Feb 16, 2017
1055cf3
Vectorize SpanHelpers
benaadams Feb 16, 2017
99964c3
fix includes
benaadams Feb 20, 2017
2ad81af
different includes?
benaadams Feb 20, 2017
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2 changes: 2 additions & 0 deletions src/System.Memory/src/System.Memory.csproj
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Original file line number Diff line number Diff line change
Expand Up @@ -37,11 +37,13 @@
<Reference Include="System.Reflection" />
<Reference Include="System.Resources.ResourceManager" />
<Reference Include="System.Runtime" />
<Reference Include="System.Numerics.Vectors" />
<Reference Condition="'$(TargetGroup)' != 'netstandard1.0'" Include="System.Runtime.CompilerServices.Unsafe" />
<ProjectReference Condition="'$(TargetGroup)' == 'netstandard1.0'" Include="..\..\System.Runtime.CompilerServices.Unsafe\ref\System.Runtime.CompilerServices.Unsafe.csproj" />
</ItemGroup>
<ItemGroup Condition="'$(IsPartialFacadeAssembly)' == 'true'">
<Reference Include="System.Runtime.CompilerServices.Unsafe" />
<Reference Include="System.Numerics.Vectors" />
<ReferenceFromRuntime Include="System.Private.CoreLib" />
<ProjectReference Include="..\..\System.Runtime\src\System.Runtime.csproj" />
<ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj" />
Expand Down
1 change: 0 additions & 1 deletion src/System.Memory/src/System/Pinnable.cs
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Expand Up @@ -2,7 +2,6 @@
// 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.InteropServices;

namespace System
Expand Down
43 changes: 19 additions & 24 deletions src/System.Memory/src/System/ReadOnlySpan.cs
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Expand Up @@ -28,8 +28,9 @@ public struct ReadOnlySpan<T>
public ReadOnlySpan(T[] array)
{
if (array == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
if (default(T) == null && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArgumentNullException_Array();
// Check will be Jitted out for ValueTypes
if (!SpanHelpers.IsValueType<T>() && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArrayTypeMismatchException_ArrayTypeMustBeExactMatch(typeof(T));

_length = array.Length;
Expand All @@ -52,16 +53,13 @@ public ReadOnlySpan(T[] array)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public ReadOnlySpan(T[] array, int start)
{
if (array == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
if (default(T) == null && array.GetType() != typeof(T[]))
if (array == null || (uint)start > (uint)array.Length)
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(array);
// Check will be Jitted out for ValueTypes
if (!SpanHelpers.IsValueType<T>() && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArrayTypeMismatchException_ArrayTypeMustBeExactMatch(typeof(T));

int arrayLength = array.Length;
if ((uint)start > (uint)arrayLength)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);

_length = arrayLength - start;
_length = array.Length - start;
_pinnable = Unsafe.As<Pinnable<T>>(array);
_byteOffset = SpanHelpers.PerTypeValues<T>.ArrayAdjustment.Add<T>(start);
}
Expand All @@ -82,12 +80,11 @@ public ReadOnlySpan(T[] array, int start)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public ReadOnlySpan(T[] array, int start, int length)
{
if (array == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
if (default(T) == null && array.GetType() != typeof(T[]))
if (array == null || (uint)start > (uint)array.Length || (uint)length > (uint)(array.Length - start))
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(array);
// Check will be Jitted out for ValueTypes
if (!SpanHelpers.IsValueType<T>() && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArrayTypeMismatchException_ArrayTypeMustBeExactMatch(typeof(T));
if ((uint)start > (uint)array.Length || (uint)length > (uint)(array.Length - start))
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);

_length = length;
_pinnable = Unsafe.As<Pinnable<T>>(array);
Expand All @@ -111,10 +108,11 @@ public ReadOnlySpan(T[] array, int start, int length)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public unsafe ReadOnlySpan(void* pointer, int length)
{
// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<T>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(T));
if (length < 0)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
ThrowHelper.ThrowArgumentOutOfRangeException_Length();

_length = length;
_pinnable = null;
Expand All @@ -138,10 +136,8 @@ public unsafe ReadOnlySpan(void* pointer, int length)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static ReadOnlySpan<T> DangerousCreate(object obj, ref T objectData, int length)
{
if (obj == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.obj);
if (length < 0)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.length);
if (obj == null || length < 0)
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(length);

Pinnable<T> pinnable = Unsafe.As<Pinnable<T>>(obj);
IntPtr byteOffset = Unsafe.ByteOffset<T>(ref pinnable.Data, ref objectData);
Expand Down Expand Up @@ -315,11 +311,10 @@ public override int GetHashCode()
public ReadOnlySpan<T> Slice(int start)
{
if ((uint)start > (uint)_length)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
ThrowHelper.ThrowArgumentOutOfRangeException_Start();

IntPtr newOffset = _byteOffset.Add<T>(start);
int length = _length - start;
return new ReadOnlySpan<T>(_pinnable, newOffset, length);
return new ReadOnlySpan<T>(_pinnable, newOffset, _length - start);
}

/// <summary>
Expand All @@ -334,7 +329,7 @@ public ReadOnlySpan<T> Slice(int start)
public ReadOnlySpan<T> Slice(int start, int length)
{
if ((uint)start > (uint)_length || (uint)length > (uint)(_length - start))
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
ThrowHelper.ThrowArgumentOutOfRangeException_Start();

IntPtr newOffset = _byteOffset.Add<T>(start);
return new ReadOnlySpan<T>(_pinnable, newOffset, length);
Expand Down
72 changes: 34 additions & 38 deletions src/System.Memory/src/System/Span.cs
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Expand Up @@ -28,8 +28,9 @@ public struct Span<T>
public Span(T[] array)
{
if (array == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
if (default(T) == null && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArgumentNullException_Array();
// Check will be Jitted out for ValueTypes
if (!SpanHelpers.IsValueType<T>() && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArrayTypeMismatchException_ArrayTypeMustBeExactMatch(typeof(T));

_length = array.Length;
Expand All @@ -52,16 +53,13 @@ public Span(T[] array)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public Span(T[] array, int start)
{
if (array == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
if (default(T) == null && array.GetType() != typeof(T[]))
if (array == null || (uint)start > (uint)array.Length)
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(array);
// Check will be Jitted out for ValueTypes
if (!SpanHelpers.IsValueType<T>() && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArrayTypeMismatchException_ArrayTypeMustBeExactMatch(typeof(T));

int arrayLength = array.Length;
if ((uint)start > (uint)arrayLength)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);

_length = arrayLength - start;
_length = array.Length - start;
_pinnable = Unsafe.As<Pinnable<T>>(array);
_byteOffset = SpanHelpers.PerTypeValues<T>.ArrayAdjustment.Add<T>(start);
}
Expand All @@ -82,12 +80,11 @@ public Span(T[] array, int start)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public Span(T[] array, int start, int length)
{
if (array == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
if (default(T) == null && array.GetType() != typeof(T[]))
if (array == null || (uint)start > (uint)array.Length || (uint)length > (uint)(array.Length - start))
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(array);
// Check will be Jitted out for ValueTypes
if (!SpanHelpers.IsValueType<T>() && array.GetType() != typeof(T[]))
ThrowHelper.ThrowArrayTypeMismatchException_ArrayTypeMustBeExactMatch(typeof(T));
if ((uint)start > (uint)array.Length || (uint)length > (uint)(array.Length - start))
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);

_length = length;
_pinnable = Unsafe.As<Pinnable<T>>(array);
Expand All @@ -111,10 +108,11 @@ public Span(T[] array, int start, int length)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public unsafe Span(void* pointer, int length)
{
// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<T>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(T));
if (length < 0)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
ThrowHelper.ThrowArgumentOutOfRangeException_Length();

_length = length;
_pinnable = null;
Expand All @@ -138,10 +136,8 @@ public unsafe Span(void* pointer, int length)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static Span<T> DangerousCreate(object obj, ref T objectData, int length)
{
if (obj == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.obj);
if (length < 0)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.length);
if (obj == null || length < 0)
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(length);

Pinnable<T> pinnable = Unsafe.As<Pinnable<T>>(obj);
IntPtr byteOffset = Unsafe.ByteOffset<T>(ref pinnable.Data, ref objectData);
Expand Down Expand Up @@ -244,6 +240,7 @@ public unsafe void Clear()

var byteLength = (UIntPtr)((uint)length * Unsafe.SizeOf<T>());

// Branch will be Jit eliminated
if ((Unsafe.SizeOf<T>() & (sizeof(IntPtr) - 1)) != 0)
{
if (_pinnable == null)
Expand All @@ -261,6 +258,7 @@ public unsafe void Clear()
}
else
{
// Branch will be Jit eliminated
if (SpanHelpers.IsReferenceOrContainsReferences<T>())
{
UIntPtr pointerSizedLength = (UIntPtr)((length * Unsafe.SizeOf<T>()) / sizeof(IntPtr));
Expand Down Expand Up @@ -288,6 +286,7 @@ public unsafe void Fill(T value)
if (length == 0)
return;

// Branch will be Jit eliminated
if (Unsafe.SizeOf<T>() == 1)
{
byte fill = Unsafe.As<T, byte>(ref value);
Expand Down Expand Up @@ -463,11 +462,10 @@ public override int GetHashCode()
public Span<T> Slice(int start)
{
if ((uint)start > (uint)_length)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
ThrowHelper.ThrowArgumentOutOfRangeException_Start();

IntPtr newOffset = _byteOffset.Add<T>(start);
int length = _length - start;
return new Span<T>(_pinnable, newOffset, length);
return new Span<T>(_pinnable, newOffset, _length - start);
}

/// <summary>
Expand All @@ -482,7 +480,7 @@ public Span<T> Slice(int start)
public Span<T> Slice(int start, int length)
{
if ((uint)start > (uint)_length || (uint)length > (uint)(_length - start))
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
ThrowHelper.ThrowArgumentOutOfRangeException_Start();

IntPtr newOffset = _byteOffset.Add<T>(start);
return new Span<T>(_pinnable, newOffset, length);
Expand Down Expand Up @@ -562,6 +560,7 @@ public static class Span
public static Span<byte> AsBytes<T>(this Span<T> source)
where T : struct
{
// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<T>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(T));

Expand All @@ -584,6 +583,7 @@ public static Span<byte> AsBytes<T>(this Span<T> source)
public static ReadOnlySpan<byte> AsBytes<T>(this ReadOnlySpan<T> source)
where T : struct
{
// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<T>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(T));

Expand All @@ -610,9 +610,10 @@ public static Span<TTo> NonPortableCast<TFrom, TTo>(this Span<TFrom> source)
where TFrom : struct
where TTo : struct
{
// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<TFrom>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(TFrom));

// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<TTo>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(TTo));

Expand All @@ -639,9 +640,10 @@ public static ReadOnlySpan<TTo> NonPortableCast<TFrom, TTo>(this ReadOnlySpan<TF
where TFrom : struct
where TTo : struct
{
// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<TFrom>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(TFrom));

// Check will be Jitted out for valid types
if (SpanHelpers.IsReferenceOrContainsReferences<TTo>())
ThrowHelper.ThrowArgumentException_InvalidTypeWithPointersNotSupported(typeof(TTo));

Expand All @@ -658,7 +660,7 @@ public static ReadOnlySpan<TTo> NonPortableCast<TFrom, TTo>(this ReadOnlySpan<TF
public static ReadOnlySpan<char> Slice(this string text)
{
if (text == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.text);
ThrowHelper.ThrowArgumentNullException_Text();

return new ReadOnlySpan<char>(Unsafe.As<Pinnable<char>>(text), StringAdjustment, text.Length);
}
Expand All @@ -675,16 +677,13 @@ public static ReadOnlySpan<char> Slice(this string text)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static ReadOnlySpan<char> Slice(this string text, int start)
{
if (text == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.text);
int textLength = text.Length;
if ((uint)start > (uint)textLength)
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
if (text == null || (uint)start > (uint)text.Length)
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(text);

unsafe
{
byte* byteOffset = ((byte*)StringAdjustment) + (uint)(start * sizeof(char));
return new ReadOnlySpan<char>(Unsafe.As<Pinnable<char>>(text), (IntPtr)byteOffset, textLength - start);
return new ReadOnlySpan<char>(Unsafe.As<Pinnable<char>>(text), (IntPtr)byteOffset, text.Length - start);
}
}

Expand All @@ -701,11 +700,8 @@ public static ReadOnlySpan<char> Slice(this string text, int start)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static ReadOnlySpan<char> Slice(this string text, int start, int length)
{
if (text == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.text);
int textLength = text.Length;
if ((uint)start > (uint)textLength || (uint)length > (uint)(textLength - start))
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.start);
if (text == null || (uint)start > (uint)text.Length || (uint)length > (uint)(text.Length - start))
ThrowHelper.ThrowArgumentNullOrOutOfRangeException(text);

unsafe
{
Expand Down
9 changes: 8 additions & 1 deletion src/System.Memory/src/System/SpanExtensions.cs
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Expand Up @@ -2,7 +2,6 @@
// 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
Expand Down Expand Up @@ -32,6 +31,10 @@ public static int IndexOf<T>(this Span<T> span, T value)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static int IndexOf(this Span<byte> span, byte value)
{
if (!BitConverter.IsLittleEndian)
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@KrzysztofCwalina KrzysztofCwalina Feb 21, 2017

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Why do we care about endianness here?

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@benaadams benaadams Feb 21, 2017

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The locate byte doesn't work on big-endian as it highlights the wrong byte (due to order reversal) aspnet/KestrelHttpServer#1138 (comment); don't know if its worth the effort to come up with something that does work on big-endian though /cc @halter73

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@KrzysztofCwalina KrzysztofCwalina Feb 21, 2017 •
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Ah, makes sense. Do you know how much this branch adds (if any) to "early" searches? i.e. search that finds the byte at index 0.

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@benaadams benaadams Feb 21, 2017 •
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It may suffer from a static base initalization check if its first use; and not do branch elimination. Subsequent uses (in different function) will branch eliminate.

@jkotas would there me any mileage in adding a use of BitConverter.IsLittleEndian to something like CommonlyUsedGenericInstantiations as they are runtime fixed and mainly used for branch elimination; so the check is pre-paid?

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@benaadams benaadams Feb 21, 2017

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Already issue for it https://github.com/dotnet/coreclr/issues/9701 serendipity 😺

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@jkotas jkotas Feb 21, 2017

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I have added comment to dotnet/coreclr#9701 on what would be needed to fix it.

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@halter73 halter73 Feb 22, 2017

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👍 For keeping a big-endian path working. It would be nice if we could test on big-endian architectures.

In Kestrel, we declared big-endian bankruptcy a while ago, so Kestrel now throws on startup if it detects that it's running on a big-endian machine. I don't think that's really an option for corefx APIs.

{
return SpanHelpers.IndexOfBigEndian(ref span.DangerousGetPinnableReference(), value, span.Length);
}
return SpanHelpers.IndexOf(ref span.DangerousGetPinnableReference(), value, span.Length);
}

Expand Down Expand Up @@ -131,6 +134,10 @@ public static int IndexOf<T>(this ReadOnlySpan<T> span, T value)
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static int IndexOf(this ReadOnlySpan<byte> span, byte value)
{
if (!BitConverter.IsLittleEndian)
{
return SpanHelpers.IndexOfBigEndian(ref span.DangerousGetPinnableReference(), value, span.Length);
}
return SpanHelpers.IndexOf(ref span.DangerousGetPinnableReference(), value, span.Length);
}

Expand Down
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