Expose IsDense, HasAnyDenseDimensions, and ToDenseTensor

src/libraries/System.Numerics.Tensors/System.Numerics.Tensors.sln

@@ -1,4 +1,8 @@
-Microsoft Visual Studio Solution File, Format Version 12.00
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36105.17 d17.14
+MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TestUtilities", "..\Common\tests\TestUtilities\TestUtilities.csproj", "{9F20CEA1-2216-4432-BBBD-F01E05D17F23}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.Bcl.Numerics", "..\Microsoft.Bcl.Numerics\src\Microsoft.Bcl.Numerics.csproj", "{1578185F-C4FA-4866-936B-E62AAEDD03B7}"
@@ -33,11 +37,11 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "ref", "ref", "{7AC4B2C7-A55
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "gen", "gen", "{841A2FA4-A95F-4612-A8B9-AD2EF769BC71}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "gen", "tools\gen", "{A21C99E7-E22B-470E-BF48-56B00AFE3D34}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "gen", "gen", "{A21C99E7-E22B-470E-BF48-56B00AFE3D34}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "tools\src", "{25B37C75-C737-4AE8-9260-74A79870C8B8}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{25B37C75-C737-4AE8-9260-74A79870C8B8}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "ref", "tools\ref", "{9482D7C5-F37C-40FC-B057-A16C1ED1C121}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "ref", "ref", "{9482D7C5-F37C-40FC-B057-A16C1ED1C121}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tools", "tools", "{F9C2AAB1-C7B0-4E43-BB18-4FB16F6E272B}"
 EndProject
@@ -105,23 +109,27 @@ Global
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{9F20CEA1-2216-4432-BBBD-F01E05D17F23} = {DE94CA7D-BB10-4865-85A6-6B694631247F}
-		{46AD9423-D8C3-44BB-A201-1CCCAB4C6DAF} = {DE94CA7D-BB10-4865-85A6-6B694631247F}
-		{4AF6A02D-82C8-4898-9EDF-01F107C25061} = {DE94CA7D-BB10-4865-85A6-6B694631247F}
 		{1578185F-C4FA-4866-936B-E62AAEDD03B7} = {DF0561A1-3AB8-4B51-AFB4-392EE1DD6247}
-		{848DD000-3D22-4A25-A9D9-05AFF857A116} = {DF0561A1-3AB8-4B51-AFB4-392EE1DD6247}
 		{21CB448A-3882-4337-B416-D1A3E0BCFFC5} = {7AC4B2C7-A55C-4C4F-9B02-77F5CBFFF4AB}
+		{848DD000-3D22-4A25-A9D9-05AFF857A116} = {DF0561A1-3AB8-4B51-AFB4-392EE1DD6247}
+		{46AD9423-D8C3-44BB-A201-1CCCAB4C6DAF} = {DE94CA7D-BB10-4865-85A6-6B694631247F}
+		{4AF6A02D-82C8-4898-9EDF-01F107C25061} = {DE94CA7D-BB10-4865-85A6-6B694631247F}
 		{D9283CC0-07E1-417A-B73C-223F3EB7A277} = {841A2FA4-A95F-4612-A8B9-AD2EF769BC71}
 		{DB954E01-898A-4FE2-A3AA-180D041AB08F} = {841A2FA4-A95F-4612-A8B9-AD2EF769BC71}
 		{04FC0651-B9D0-448A-A28B-11B1D4A897F4} = {A21C99E7-E22B-470E-BF48-56B00AFE3D34}
 		{683A7D28-CC55-4375-848D-E659075ECEE4} = {A21C99E7-E22B-470E-BF48-56B00AFE3D34}
-		{A21C99E7-E22B-470E-BF48-56B00AFE3D34} = {F9C2AAB1-C7B0-4E43-BB18-4FB16F6E272B}
 		{1CBEAEA8-2CA1-4B07-9930-35A785205852} = {25B37C75-C737-4AE8-9260-74A79870C8B8}
 		{BA7828B1-7953-47A0-AE5A-E22B501C4BD0} = {25B37C75-C737-4AE8-9260-74A79870C8B8}
-		{25B37C75-C737-4AE8-9260-74A79870C8B8} = {F9C2AAB1-C7B0-4E43-BB18-4FB16F6E272B}
 		{57E57290-3A6A-43F8-8764-D4DC8151F89C} = {9482D7C5-F37C-40FC-B057-A16C1ED1C121}
+		{A21C99E7-E22B-470E-BF48-56B00AFE3D34} = {F9C2AAB1-C7B0-4E43-BB18-4FB16F6E272B}
+		{25B37C75-C737-4AE8-9260-74A79870C8B8} = {F9C2AAB1-C7B0-4E43-BB18-4FB16F6E272B}
 		{9482D7C5-F37C-40FC-B057-A16C1ED1C121} = {F9C2AAB1-C7B0-4E43-BB18-4FB16F6E272B}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {10A5F2C3-5230-4916-9D4D-BBDB94851037}
 	EndGlobalSection
+	GlobalSection(SharedMSBuildProjectFiles) = preSolution
+		..\..\tools\illink\src\ILLink.Shared\ILLink.Shared.projitems*{683a7d28-cc55-4375-848d-e659075ecee4}*SharedItemsImports = 5
+		..\..\tools\illink\src\ILLink.Shared\ILLink.Shared.projitems*{ba7828b1-7953-47a0-ae5a-e22b501c4bd0}*SharedItemsImports = 5
+	EndGlobalSection
 EndGlobal

src/libraries/System.Numerics.Tensors/ref/System.Numerics.Tensors.netcore.cs

@@ -59,6 +59,8 @@ namespace System.Numerics.Tensors
     public partial interface IReadOnlyTensor
     {
         nint FlattenedLength { get; }
+        bool HasAnyDenseDimensions { get; }
+        bool IsDense { get; }
         bool IsEmpty { get; }
         bool IsPinned { get; }
         object this[params scoped System.ReadOnlySpan<System.Buffers.NIndex> indexes] { get; }
@@ -87,6 +89,7 @@ public partial interface IReadOnlyTensor<TSelf, T> : System.Collections.Generic.
         TSelf Slice(params scoped System.ReadOnlySpan<System.Buffers.NIndex> startIndexes);
         TSelf Slice(params scoped System.ReadOnlySpan<System.Buffers.NRange> ranges);
         TSelf Slice(params scoped System.ReadOnlySpan<nint> startIndexes);
+        TSelf ToDenseTensor();
         bool TryCopyTo(scoped System.Numerics.Tensors.TensorSpan<T> destination);
         bool TryFlattenTo(scoped System.Span<T> destination);
     }
@@ -138,6 +141,8 @@ public readonly ref partial struct ReadOnlyTensorSpan<T>
         public ReadOnlyTensorSpan(T[]? array, int start, scoped System.ReadOnlySpan<nint> lengths, scoped System.ReadOnlySpan<nint> strides) { throw null; }
         public static System.Numerics.Tensors.ReadOnlyTensorSpan<T> Empty { get { throw null; } }
         public nint FlattenedLength { get { throw null; } }
+        public bool HasAnyDenseDimensions { get { throw null; } }
+        public bool IsDense { get { throw null; } }
         public bool IsEmpty { get { throw null; } }
         public ref readonly T this[params scoped System.ReadOnlySpan<System.Buffers.NIndex> indexes] { get { throw null; } }
         public System.Numerics.Tensors.ReadOnlyTensorSpan<T> this[params scoped System.ReadOnlySpan<System.Buffers.NRange> ranges] { get { throw null; } }
@@ -805,6 +810,8 @@ public readonly ref partial struct TensorSpan<T>
         public TensorSpan(T[]? array, int start, scoped System.ReadOnlySpan<nint> lengths, scoped System.ReadOnlySpan<nint> strides) { throw null; }
         public static System.Numerics.Tensors.TensorSpan<T> Empty { get { throw null; } }
         public nint FlattenedLength { get { throw null; } }
+        public bool HasAnyDenseDimensions { get { throw null; } }
+        public bool IsDense { get { throw null; } }
         public bool IsEmpty { get { throw null; } }
         public ref T this[params scoped System.ReadOnlySpan<System.Buffers.NIndex> indexes] { get { throw null; } }
         public System.Numerics.Tensors.TensorSpan<T> this[params scoped System.ReadOnlySpan<System.Buffers.NRange> ranges] { get { throw null; } set { } }
@@ -863,6 +870,8 @@ public sealed partial class Tensor<T> : System.Collections.Generic.IEnumerable<T
         internal Tensor() { }
         public static System.Numerics.Tensors.Tensor<T> Empty { get { throw null; } }
         public nint FlattenedLength { get { throw null; } }
+        public bool HasAnyDenseDimensions { get { throw null; } }
+        public bool IsDense { get { throw null; } }
         public bool IsEmpty { get { throw null; } }
         public bool IsPinned { get { throw null; } }
         public ref T this[params scoped System.ReadOnlySpan<System.Buffers.NIndex> indexes] { get { throw null; } }
@@ -915,6 +924,7 @@ void System.Numerics.Tensors.ITensor.Fill(object value) { }
         static System.Numerics.Tensors.Tensor<T> System.Numerics.Tensors.ITensor<System.Numerics.Tensors.Tensor<T>, T>.Create(scoped System.ReadOnlySpan<nint> lengths, scoped System.ReadOnlySpan<nint> strides, bool pinned) { throw null; }
         static System.Numerics.Tensors.Tensor<T> System.Numerics.Tensors.ITensor<System.Numerics.Tensors.Tensor<T>, T>.CreateUninitialized(scoped System.ReadOnlySpan<nint> lengths, bool pinned) { throw null; }
         static System.Numerics.Tensors.Tensor<T> System.Numerics.Tensors.ITensor<System.Numerics.Tensors.Tensor<T>, T>.CreateUninitialized(scoped System.ReadOnlySpan<nint> lengths, scoped System.ReadOnlySpan<nint> strides, bool pinned) { throw null; }
+        public Tensor<T> ToDenseTensor() { throw null; }
         public string ToString(scoped System.ReadOnlySpan<nint> maximumLengths) { throw null; }
         public bool TryCopyTo(scoped System.Numerics.Tensors.TensorSpan<T> destination) { throw null; }
         public bool TryFlattenTo(scoped System.Span<T> destination) { throw null; }

src/libraries/System.Numerics.Tensors/src/CompatibilitySuppressions.xml

@@ -337,6 +337,20 @@
     <Right>lib/net9.0/System.Numerics.Tensors.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:System.Numerics.Tensors.IReadOnlyTensor`2.ToDenseTensor</Target>
+    <Left>lib/net8.0/System.Numerics.Tensors.dll</Left>
+    <Right>lib/net8.0/System.Numerics.Tensors.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:System.Numerics.Tensors.IReadOnlyTensor`2.ToDenseTensor</Target>
+    <Left>lib/net9.0/System.Numerics.Tensors.dll</Left>
+    <Right>lib/net9.0/System.Numerics.Tensors.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0017</DiagnosticId>
     <Target>M:System.Numerics.Tensors.IReadOnlyTensor`2.AsReadOnlyTensorSpan(System.ReadOnlySpan{System.Buffers.NIndex})$0</Target>

src/libraries/System.Numerics.Tensors/src/System/Numerics/Tensors/netcore/IReadOnlyTensor.cs

@@ -26,6 +26,20 @@ public interface IReadOnlyTensor
         /// <summary>Gets the total number of items in the tensor.</summary>
         nint FlattenedLength { get; }
 
+        /// <summary>Determines if the current tensor has any dimension where <c>GetDimensionSpan(int)</c> will iterate through tensors that would have <see cref="IsDense" /> be <c>true</c>.</summary>
+        /// <remarks>
+        ///   <para>This does not include the last dimension, <c>GetDimensionSpan(Rank - 1)</c>, as it always iterates 1 element at a time and would mean this property always returns true.</para>
+        ///   <para>An example of a tensor which is not dense but which would have a dense dimension is a 2x2 Tensor where <c>FlattenedLength: 4; Lengths: [2, 2]; Strides: [4, 1]</c>. In such a scenario, the overall tensor is not dense because the backing storage has a length of at least 6 and so has 2 used elements, 2 unused elements, followed by the last 2 used elements. However, the two slices representing <c>[0..1, ..]</c> and <c>[1..2, ..]</c> would themselves be dense; thus <c>GetDimension(0).GetSlice(n)</c> will iterate dense tensors: <c>FlattenedLength: 2, Length: [2], Strides: [1]</c>.</para>
+        /// </remarks>
+        bool HasAnyDenseDimensions { get; }
+
+        /// <summary>Determines if the current tensor is dense.</summary>
+        /// <remarks>
+        ///   <para>A dense tensor is one where the elements are ordered sequentially in memory and where no gaps exist between the elements.</para>
+        ///   <para>For a 2x2 Tensor, this would mean it has <c>FlattenedLength: 4; Lengths: [2, 2]; Strides: [2, 1]</c>. The elements would be sequentially accessed via indexes: <c>[0, 0]; [0, 1]; [1, 0]; [1, 1]</c></para>
+        /// </remarks>
+        bool IsDense { get; }
+
         /// <summary>Gets a value indicating whether this tensor is empty.</summary>
         /// <value><see langword="true"/> if this tensor is empty; otherwise, <see langword="false"/>.</value>
         bool IsEmpty { get; }

src/libraries/System.Numerics.Tensors/src/System/Numerics/Tensors/netcore/IReadOnlyTensor_1.cs

@@ -82,6 +82,14 @@ public interface IReadOnlyTensor<TSelf, T> : IReadOnlyTensor, IEnumerable<T>
         /// <exception cref="ArgumentOutOfRangeException"><paramref name="ranges" /> is larger than the tensor.</exception>
         TSelf Slice(params scoped ReadOnlySpan<NRange> ranges);
 
+        /// <summary>Creates a dense tensor from the elements of the current tensor.</summary>
+        /// <returns>The current tensor if it is already dense; otherwise, a new tensor that contains the elements of this tensor.</returns>
+        /// <remarks>
+        ///   <para>A dense tensor is one where the elements are ordered sequentially in memory and where no gaps exist between the elements.</para>
+        ///   <para>For a 2x2 Tensor, this would mean it has <c>FlattendLength: 4; Lengths: [2, 2]; Strides: [4, 1]</c>. The elements would be sequentially accessed via indexes: <c>[0, 0]; [0, 1]; [1, 0]; [1, 1]</c></para>
+        /// </remarks>
+        TSelf ToDenseTensor();
+
         /// <summary>Attempts to copy the contents of this tensor into a destination tensor span and returns a value to indicate whether or not the operation succeeded.</summary>
         /// <param name="destination">The target of the copy operation.</param>
         /// <returns><see langword="true"/> if the copy operation succeeded; otherwise, <c>false</c>.</returns>

src/libraries/System.Numerics.Tensors/src/System/Numerics/Tensors/netcore/ReadOnlyTensorSpan_1.cs

@@ -299,7 +299,11 @@ public ReadOnlyTensorSpan<T> this[params scoped ReadOnlySpan<NRange> ranges]
         /// <inheritdoc cref="IReadOnlyTensor.FlattenedLength" />
         public nint FlattenedLength => _shape.FlattenedLength;
 
-        internal bool IsContiguousAndDense => _shape.IsContiguousAndDense;
+        /// <inheritdoc cref="IReadOnlyTensor.HasAnyDenseDimensions" />
+        public bool HasAnyDenseDimensions => _shape.HasAnyDenseDimensions;
+
+        /// <inheritdoc cref="IReadOnlyTensor.IsDense" />
+        public bool IsDense => _shape.IsDense;
 
         /// <inheritdoc cref="IReadOnlyTensor.IsEmpty" />
         public bool IsEmpty => _shape.IsEmpty;

src/libraries/System.Numerics.Tensors/src/System/Numerics/Tensors/netcore/Tensor.cs

@@ -1440,7 +1440,7 @@ public static Tensor<T> Reshape<T>(this Tensor<T> tensor, ReadOnlySpan<nint> len
             if (tensor.Lengths.SequenceEqual(lengths))
                 return tensor;
 
-            if (!tensor.IsContiguousAndDense && !tensor.Strides.Contains(0))
+            if (!tensor.IsDense && !tensor.Strides.Contains(0))
             {
                 ThrowHelper.ThrowArgument_CannotReshapeNonContiguousOrDense();
             }
@@ -1513,7 +1513,7 @@ public static TensorSpan<T> Reshape<T>(in this TensorSpan<T> tensor, scoped Read
             if (tensor.Lengths.SequenceEqual(lengths))
                 return tensor;
 
-            if (!tensor.IsContiguousAndDense && !tensor.Strides.Contains(0))
+            if (!tensor.IsDense && !tensor.Strides.Contains(0))
             {
                 ThrowHelper.ThrowArgument_CannotReshapeNonContiguousOrDense();
             }
@@ -1589,7 +1589,7 @@ public static ReadOnlyTensorSpan<T> Reshape<T>(in this ReadOnlyTensorSpan<T> ten
             if (tensor.Lengths.SequenceEqual(lengths))
                 return tensor;
 
-            if (!tensor.IsContiguousAndDense && !tensor.Strides.Contains(0))
+            if (!tensor.IsDense && !tensor.Strides.Contains(0))
             {
                 ThrowHelper.ThrowArgument_CannotReshapeNonContiguousOrDense();
             }