Addressed PR comments.

Author: NiklasGustafsson

src/TorchSharp/Tensor/Tensor.cs

@@ -5185,13 +5185,13 @@ public Tensor roll((long, long, long) shifts, (long, long, long) dims)
             /// Elements that are shifted beyond the last position are re-introduced at the first position.
             /// If a dimension is not specified, the tensor will be flattened before rolling and then restored to the original shape.
             /// </summary>
-            public Tensor roll(IEnumerable<long> shifts, IEnumerable<long>? dims = null)
+            public Tensor roll(ReadOnlySpan<long> shifts, IEnumerable<long>? dims = null)
             {
-                var shLen = shifts.Count();
+                var shLen = shifts.Length;
                 var dmLen = dims is null ? 0 : dims.Count();
 
                 unsafe {
-                    fixed (long* sh = shifts.ToArray(), dm = (dims == null) ? null : dims.ToArray()) {
+                    fixed (long* sh = shifts, dm = (dims == null) ? null : dims.ToArray()) {
                         var res =
                             THSTensor_roll(Handle, (IntPtr)sh, shLen, (IntPtr)dm, dmLen);
                         if (res == IntPtr.Zero) { torch.CheckForErrors(); }

src/TorchSharp/Tensor/Tensor.torch.cs

@@ -95,7 +95,7 @@ public static Tensor cat(IList<Tensor> tensors, long dimension)
         /// Elements that are shifted beyond the last position are re-introduced at the first position.
         /// If a dimension is not specified, the tensor will be flattened before rolling and then restored to the original shape.
         /// </summary>
-        public static Tensor roll(Tensor input, IEnumerable<long> shifts, IEnumerable<long> dims) => input.roll(shifts, dims);
+        public static Tensor roll(Tensor input, ReadOnlySpan<long> shifts, IEnumerable<long> dims) => input.roll(shifts, dims);
 
         /// <summary>
         /// Returns a tensor with all the dimensions of input of size 1 removed. When dim is given, a squeeze operation is done only in the given dimension.