[release/8.0] Numerics and Tensors backport

src/coreclr/jit/utils.cpp

@@ -2734,7 +2734,7 @@ float FloatingPointUtils::maximumNumber(float x, float y)
 //
 // It propagates NaN inputs back to the caller and
 // otherwise returns the lesser of the inputs. It
-// treats +0 as lesser than -0 as per the specification.
+// treats +0 as greater than -0 as per the specification.
 //
 // Arguments:
 //    val1 - left operand
@@ -2763,7 +2763,7 @@ double FloatingPointUtils::minimum(double val1, double val2)
 //
 // It propagates NaN inputs back to the caller and
 // otherwise returns the input with a lesser magnitude.
-// It treats +0 as lesser than -0 as per the specification.
+// It treats +0 as greater than -0 as per the specification.
 //
 // Arguments:
 //    x - left operand
@@ -2856,7 +2856,7 @@ double FloatingPointUtils::minimumNumber(double x, double y)
 //
 // It propagates NaN inputs back to the caller and
 // otherwise returns the lesser of the inputs. It
-// treats +0 as lesser than -0 as per the specification.
+// treats +0 as greater than -0 as per the specification.
 //
 // Arguments:
 //    val1 - left operand
@@ -2885,7 +2885,7 @@ float FloatingPointUtils::minimum(float val1, float val2)
 //
 // It propagates NaN inputs back to the caller and
 // otherwise returns the input with a lesser magnitude.
-// It treats +0 as lesser than -0 as per the specification.
+// It treats +0 as greater than -0 as per the specification.
 //
 // Arguments:
 //    x - left operand

src/libraries/Common/tests/TestUtilities/System/Buffers/BoundedMemory.Unix.cs

@@ -30,6 +30,8 @@ public UnixImplementation(int elementCount)
 
             public override bool IsReadonly => false;
 
+            public override int Length => _elementCount;
+
             public override Memory<T> Memory => _memoryManager.Memory;
 
             public override Span<T> Span
@@ -83,10 +85,7 @@ protected override void Dispose(bool disposing)
                     // no-op; the handle will be disposed separately
                 }
 
-                public override Span<T> GetSpan()
-                {
-                    throw new NotImplementedException();
-                }
+                public override Span<T> GetSpan() => _impl.Span;
 
                 public override MemoryHandle Pin(int elementIndex)
                 {

src/libraries/Common/tests/TestUtilities/System/Buffers/BoundedMemory.Windows.cs

@@ -81,6 +81,8 @@ internal WindowsImplementation(VirtualAllocHandle handle, int byteOffsetIntoHand
 
             public override bool IsReadonly => (Protection != VirtualAllocProtection.PAGE_READWRITE);
 
+            public override int Length => _elementCount;
+
             internal VirtualAllocProtection Protection
             {
                 get
@@ -189,10 +191,7 @@ protected override void Dispose(bool disposing)
                     // no-op; the handle will be disposed separately
                 }
 
-                public override Span<T> GetSpan()
-                {
-                    throw new NotImplementedException();
-                }
+                public override Span<T> GetSpan() => _impl.Span;
 
                 public override MemoryHandle Pin(int elementIndex)
                 {

src/libraries/Common/tests/TestUtilities/System/Buffers/BoundedMemory.cs

@@ -14,6 +14,9 @@ public abstract class BoundedMemory<T> : IDisposable where T : unmanaged
         /// </summary>
         public abstract bool IsReadonly { get; }
 
+        /// <summary>Gets the length of the <see cref="BoundedMemory{T}"/> instance.</summary>
+        public abstract int Length { get; }
+
         /// <summary>
         /// Gets the <see cref="Memory{Byte}"/> which represents this native memory.
         /// This <see cref="BoundedMemory{T}"/> instance must be kept alive while working with the <see cref="Memory{Byte}"/>.
@@ -44,5 +47,23 @@ public abstract class BoundedMemory<T> : IDisposable where T : unmanaged
         /// OS does not support marking the memory block as read+write.
         /// </summary>
         public abstract void MakeWriteable();
+
+        /// <summary>
+        /// Gets the <see cref="Span{Byte}"/> which represents this native memory.
+        /// This <see cref="BoundedMemory{T}"/> instance must be kept alive while working with the <see cref="Span{Byte}"/>.
+        /// </summary>
+        public static implicit operator Span<T>(BoundedMemory<T> boundedMemory) => boundedMemory.Span;
+
+        /// <summary>
+        /// Gets the <see cref="ReadOnlySpan{Byte}"/> which represents this native memory.
+        /// This <see cref="BoundedMemory{T}"/> instance must be kept alive while working with the <see cref="ReadOnlySpan{Byte}"/>.
+        /// </summary>
+        public static implicit operator ReadOnlySpan<T>(BoundedMemory<T> boundedMemory) => boundedMemory.Span;
+
+        /// <summary>
+        /// Gets a reference to the element at the specified index.
+        /// This <see cref="BoundedMemory{T}"/> instance must be kept alive while working with the reference.
+        /// </summary>
+        public ref T this[int index] => ref Span[index];
     }
 }

src/libraries/Microsoft.Bcl.Numerics/src/PACKAGE.md

@@ -10,7 +10,22 @@ As of .NET Core 2.0 and .NET Standard 2.1, the C# language has support for math
 
 ## How to Use
 
-<!-- A compelling example on how to use this package with code, as well as any specific guidelines for when to use the package -->
+```C#
+using System;
+using System.MathF.
+
+internal static class Program
+{
+    private static async Task Main()
+    {
+        Console.WriteLine("Starting...");
+
+        Console.WriteLine(MathF.Max(1f, 5f)); // returns 5f
+
+        Console.WriteLine("Finished!");
+    }
+}
+```
 
 ```C#
 using System;

src/libraries/System.Numerics.Tensors/README.md

@@ -1,2 +1,3 @@
 # System.Numerics.Tensors
-This library has not been shipped publicly and is not accepting contributions at this time.
+
+Provides APIs for performing primitive operations over tensors represented by spans of memory.