Adding Span API perf tests for comparison with arrays and to monitor progress (#9790)

* wip

* Adding Span API perf tests for comparison with arrays and to monitor progress

* Reducing iteration count so tests finish in < 2 minutes

* Reducing the number of test cases

* Commenting out ref DangerousGetPinnableReference test

* Updated csproj to use latest compiler

* Tuning test cases and runtime

2 files changed, 843 insertions, 316 deletions

diff --git a/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.cs b/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.cs
index 7ec2a4a088..b0358d2268 100644
--- a/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.cs
+++ b/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.cs
@@ -2,467 +2,992 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.Xunit.Performance;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Text;
 using Xunit;
+using Microsoft.Xunit.Performance;
 
 [assembly: OptimizeForBenchmarks]
 [assembly: MeasureInstructionsRetired]
 
-class Tests
+namespace Span
 {
+    public class SpanBench
+    {
 
 #if DEBUG
-    const int Iterations = 1;
+        const int BubbleSortIterations = 1;
+        const int QuickSortIterations = 1;
+        const int FillAllIterations = 1;
+        const int BaseIterations = 1;
 #else
-    const int Iterations = 10000;
+        const int BubbleSortIterations = 100;
+        const int QuickSortIterations = 1000;
+        const int FillAllIterations = 100000;
+        const int BaseIterations = 10000000;
 #endif
 
-    const int Size = 1024;
+        const int Size = 1024;
 
+        // Helpers
+        #region Helpers
+        [StructLayout(LayoutKind.Sequential)]
+        private sealed class TestClass<T>
+        {
+            private double _d;
+            public T[] C0;
+        }
 
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void TestFillAllSpan(Span<byte> span)
-    {
-        for (int i = 0; i < span.Length; ++i) {
-            span[i] = unchecked((byte)i);
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void TestFillAllSpan(Span<byte> span)
+        {
+            for (int i = 0; i < span.Length; ++i) {
+                span[i] = unchecked((byte)i);
+            }
         }
-    }
 
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void TestFillAllArray(byte[] data)
-    {
-        for (int i = 0; i < data.Length; ++i) {
-            data[i] = unchecked((byte)i);
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void TestFillAllArray(byte[] data)
+        {
+            for (int i = 0; i < data.Length; ++i) {
+                data[i] = unchecked((byte)i);
+            }
         }
-    }
 
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void TestFillAllReverseSpan(Span<byte> span)
-    {
-        for (int i = span.Length; --i >= 0;) {
-            span[i] = unchecked((byte)i);
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void TestFillAllReverseSpan(Span<byte> span)
+        {
+            for (int i = span.Length; --i >= 0;) {
+                span[i] = unchecked((byte)i);
+            }
         }
-    }
 
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void TestFillAllReverseArray(byte[] data)
-    {
-        for (int i = data.Length; --i >= 0;) {
-            data[i] = unchecked((byte)i);
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void TestFillAllReverseArray(byte[] data)
+        {
+            for (int i = data.Length; --i >= 0;) {
+                data[i] = unchecked((byte)i);
+            }
         }
-    }
 
-    static int[] GetUnsortedData()
-    {
-        int[] unsortedData = new int[Size];
-        Random r = new Random(42);
-        for (int i = 0; i < unsortedData.Length; ++i)
+        static int[] GetUnsortedData()
         {
-            unsortedData[i] = r.Next();
+            int[] unsortedData = new int[Size];
+            Random r = new Random(42);
+            for (int i = 0; i < unsortedData.Length; ++i)
+            {
+                unsortedData[i] = r.Next();
+            }
+            return unsortedData;
         }
-        return unsortedData;
-    }
 
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void TestBubbleSortSpan(Span<int> span)
-    {
-        bool swap;
-        int temp;
-        int n = span.Length - 1;
-        do {
-            swap = false;
-            for (int i = 0; i < n; i++) {
-                if (span[i] > span[i + 1]) {
-                    temp = span[i];
-                    span[i] = span[i + 1];
-                    span[i + 1] = temp;
-                    swap = true;
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void TestBubbleSortSpan(Span<int> span)
+        {
+            bool swap;
+            int temp;
+            int n = span.Length - 1;
+            do {
+                swap = false;
+                for (int i = 0; i < n; i++) {
+                    if (span[i] > span[i + 1]) {
+                        temp = span[i];
+                        span[i] = span[i + 1];
+                        span[i + 1] = temp;
+                        swap = true;
+                    }
                 }
+                --n;
             }
-            --n;
+            while (swap);
         }
-        while (swap);
-    }
 
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void TestBubbleSortArray(int[] data)
-    {
-        bool swap;
-        int temp;
-        int n = data.Length - 1;
-        do {
-            swap = false;
-            for (int i = 0; i < n; i++) {
-                if (data[i] > data[i + 1]) {
-                    temp = data[i];
-                    data[i] = data[i + 1];
-                    data[i + 1] = temp;
-                    swap = true;
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void TestBubbleSortArray(int[] data)
+        {
+            bool swap;
+            int temp;
+            int n = data.Length - 1;
+            do {
+                swap = false;
+                for (int i = 0; i < n; i++) {
+                    if (data[i] > data[i + 1]) {
+                        temp = data[i];
+                        data[i] = data[i + 1];
+                        data[i + 1] = temp;
+                        swap = true;
+                    }
                 }
+                --n;
             }
-            --n;
+            while (swap);
         }
-        while (swap);
-    }
 
-    static void TestQuickSortSpan(Span<int> data)
-    {
-        QuickSortSpan(data);
-    }
-
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void QuickSortSpan(Span<int> data)
-    {
-        if (data.Length <= 1) {
-            return;
+        static void TestQuickSortSpan(Span<int> data)
+        {
+            QuickSortSpan(data);
         }
 
-        int lo = 0;
-        int hi = data.Length - 1;
-        int i, j;
-        int pivot, temp;
-        for (i = lo, j = hi, pivot = data[hi]; i < j;) {
-            while (i < j && data[i] <= pivot) {
-                ++i;
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void QuickSortSpan(Span<int> data)
+        {
+            if (data.Length <= 1) {
+                return;
             }
-            while (j > i && data[j] >= pivot) {
-                --j;
+
+            int lo = 0;
+            int hi = data.Length - 1;
+            int i, j;
+            int pivot, temp;
+            for (i = lo, j = hi, pivot = data[hi]; i < j;) {
+                while (i < j && data[i] <= pivot) {
+                    ++i;
+                }
+                while (j > i && data[j] >= pivot) {
+                    --j;
+                }
+                if (i < j) {
+                    temp = data[i];
+                    data[i] = data[j];
+                    data[j] = temp;
+                }
             }
-            if (i < j) {
+            if (i != hi) {
                 temp = data[i];
-                data[i] = data[j];
-                data[j] = temp;
+                data[i] = pivot;
+                data[hi] = temp;
             }
-        }
-        if (i != hi) {
-            temp = data[i];
-            data[i] = pivot;
-            data[hi] = temp;
-        }
-
-        QuickSortSpan(data.Slice(0, i));
-        QuickSortSpan(data.Slice(i + 1));
-    }
 
-    static void TestQuickSortArray(int[] data)
-    {
-        QuickSortArray(data, 0, data.Length - 1);
-    }
+            QuickSortSpan(data.Slice(0, i));
+            QuickSortSpan(data.Slice(i + 1));
+        }
 
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    static void QuickSortArray(int[] data, int lo, int hi)
-    {
-        if (lo >= hi) {
-            return;
+        static void TestQuickSortArray(int[] data)
+        {
+            QuickSortArray(data, 0, data.Length - 1);
         }
 
-        int i, j;
-        int pivot, temp;
-        for (i = lo, j = hi, pivot = data[hi]; i < j;) {
-            while (i < j && data[i] <= pivot) {
-                ++i;
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static void QuickSortArray(int[] data, int lo, int hi)
+        {
+            if (lo >= hi) {
+                return;
             }
-            while (j > i && data[j] >= pivot) {
-                --j;
+
+            int i, j;
+            int pivot, temp;
+            for (i = lo, j = hi, pivot = data[hi]; i < j;) {
+                while (i < j && data[i] <= pivot) {
+                    ++i;
+                }
+                while (j > i && data[j] >= pivot) {
+                    --j;
+                }
+                if (i < j) {
+                    temp = data[i];
+                    data[i] = data[j];
+                    data[j] = temp;
+                }
             }
-            if (i < j) {
+            if (i != hi) {
                 temp = data[i];
-                data[i] = data[j];
-                data[j] = temp;
+                data[i] = pivot;
+                data[hi] = temp;
             }
-        }
-        if (i != hi) {
-            temp = data[i];
-            data[i] = pivot;
-            data[hi] = temp;
-        }
 
-        QuickSortArray(data, lo, i - 1);
-        QuickSortArray(data, i + 1, hi);
-    }
-
-    // XUNIT-PERF tests
+            QuickSortArray(data, lo, i - 1);
+            QuickSortArray(data, i + 1, hi);
+        }
+        #endregion
 
-    [Benchmark]
-    public static void FillAllSpan()
-    {
-        byte[] a = new byte[Size];
-        Span<byte> s = new Span<byte>(a);
-        foreach (var iteration in Benchmark.Iterations)
+        // XUNIT-PERF tests
+        #region XUNIT-PERF tests
+        [Benchmark]
+        public static void FillAllSpan()
         {
-            using (iteration.StartMeasurement())
+            byte[] a = new byte[Size];
+            Span<byte> s = new Span<byte>(a);
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    TestFillAllSpan(s);
+                    for (int i = 0; i < FillAllIterations; i++)
+                    {
+                        TestFillAllSpan(s);
+                    }
                 }
             }
         }
-    }
 
-    [Benchmark]
-    public static void FillAllArray()
-    {
-        byte[] a = new byte[Size];
-        foreach (var iteration in Benchmark.Iterations)
+        [Benchmark]
+        public static void FillAllArray()
         {
-            using (iteration.StartMeasurement())
+            byte[] a = new byte[Size];
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    TestFillAllArray(a);
+                    for (int i = 0; i < FillAllIterations; i++)
+                    {
+                        TestFillAllArray(a);
+                    }
                 }
             }
         }
-    }
 
-    [Benchmark]
-    public static void FillAllReverseSpan()
-    {
-        byte[] a = new byte[Size];
-        Span<byte> s = new Span<byte>(a);
-        foreach (var iteration in Benchmark.Iterations)
+        [Benchmark]
+        public static void FillAllReverseSpan()
         {
-            using (iteration.StartMeasurement())
+            byte[] a = new byte[Size];
+            Span<byte> s = new Span<byte>(a);
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    TestFillAllReverseSpan(s);
+                    for (int i = 0; i < FillAllIterations; i++)
+                    {
+                        TestFillAllReverseSpan(s);
+                    }
                 }
             }
         }
-    }
 
-    [Benchmark]
-    public static void FillAllReverseArray()
-    {
-        byte[] a = new byte[Size];
-        foreach (var iteration in Benchmark.Iterations)
+        [Benchmark]
+        public static void FillAllReverseArray()
         {
-            using (iteration.StartMeasurement())
+            byte[] a = new byte[Size];
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    TestFillAllReverseArray(a);
+                    for (int i = 0; i < FillAllIterations; i++)
+                    {
+                        TestFillAllReverseArray(a);
+                    }
                 }
             }
         }
-    }
-
-    [Benchmark]
-    public static void QuickSortSpan()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
-        Span<int> span = new Span<int>(data);
 
-        foreach (var iteration in Benchmark.Iterations)
+        [Benchmark]
+        public static void QuickSortSpan()
         {
-            using (iteration.StartMeasurement())
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
+            Span<int> span = new Span<int>(data);
+
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    Array.Copy(unsortedData, data, Size);
-                    TestQuickSortSpan(span);
+                    for (int i = 0; i < QuickSortIterations; i++)
+                    {
+                        Array.Copy(unsortedData, data, Size);
+                        TestQuickSortSpan(span);
+                    }
                 }
             }
         }
-    }
-
-    [Benchmark]
-    public static void BubbleSortSpan()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
-        Span<int> span = new Span<int>(data);
 
-        foreach (var iteration in Benchmark.Iterations)
+        [Benchmark]
+        public static void BubbleSortSpan()
         {
-            using (iteration.StartMeasurement())
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
+            Span<int> span = new Span<int>(data);
+
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    Array.Copy(unsortedData, data, Size);
-                    TestBubbleSortSpan(span);
+                    for (int i = 0; i < BubbleSortIterations; i++)
+                    {
+                        Array.Copy(unsortedData, data, Size);
+                        TestBubbleSortSpan(span);
+                    }
                 }
             }
         }
-    }
 
-    [Benchmark]
-    public static void QuickSortArray()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
-
-        foreach (var iteration in Benchmark.Iterations)
+        [Benchmark]
+        public static void QuickSortArray()
         {
-            using (iteration.StartMeasurement())
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
+
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    Array.Copy(unsortedData, data, Size);
-                    TestQuickSortArray(data);
+                    for (int i = 0; i < QuickSortIterations; i++)
+                    {
+                        Array.Copy(unsortedData, data, Size);
+                        TestQuickSortArray(data);
+                    }
                 }
             }
         }
-    }
 
-    [Benchmark]
-    public static void BubbleSortArray()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
-
-        foreach (var iteration in Benchmark.Iterations)
+        [Benchmark]
+        public static void BubbleSortArray()
         {
-            using (iteration.StartMeasurement())
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
+
+            foreach (var iteration in Benchmark.Iterations)
             {
-                for (int i = 0; i < Iterations; i++)
+                using (iteration.StartMeasurement())
                 {
-                    Array.Copy(unsortedData, data, Size);
-                    TestBubbleSortArray(data);
+                    for (int i = 0; i < BubbleSortIterations; i++)
+                    {
+                        Array.Copy(unsortedData, data, Size);
+                        TestBubbleSortArray(data);
+                    }
                 }
             }
         }
-    }
+        #endregion
+
+        // TestSpanAPIs (For comparison with Array and Slow Span)
+        #region TestSpanAPIs
+
+        #region TestSpanConstructor<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanConstructorByte(int length)
+        {
+            var array = new byte[length];
+            Span<byte> span;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span = new Span<byte>(array);
+        }
 
-    // EXE-based testing
+        [Benchmark(InnerIterationCount = BaseIterations / 100)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanConstructorString(int length)
+        {
+            var array = new string[length];
+            Span<string> span;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span = new Span<string>(array);
+        }
+        #endregion
+        
+        #region TestSpanDangerousCreate<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanDangerousCreateByte(int length)
+        {
+            TestClass<byte> testClass = new TestClass<byte>();
+            testClass.C0 = new byte[length];
+            Span<byte> span;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span = Span<byte>.DangerousCreate(testClass, ref testClass.C0[0], testClass.C0.Length);
+        }
 
-    static void FillAllSpanBase()
-    {
-        byte[] a = new byte[Size];
-        Span<byte> s = new Span<byte>(a);
-        for (int i = 0; i < Iterations; i++)
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanDangerousCreateString(int length)
         {
-            TestFillAllSpan(s);
+            TestClass<string> testClass = new TestClass<string>();
+            testClass.C0 = new string[length];
+            Span<string> span;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span = Span<string>.DangerousCreate(testClass, ref testClass.C0[0], testClass.C0.Length);
+        }
+        #endregion
+
+        #region TestSpanDangerousGetPinnableReference<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanDangerousGetPinnableReferenceByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                    {
+                        ref byte temp = ref span.DangerousGetPinnableReference();
+                    }
         }
-    }
 
-    static void FillAllArrayBase()
-    {
-        byte[] a = new byte[Size];
-        for (int i = 0; i < Iterations; i++)
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanDangerousGetPinnableReferenceString(int length)
         {
-            TestFillAllArray(a);
+            var array = new string[length];
+            var span = new Span<string>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                    {
+                        ref string temp = ref span.DangerousGetPinnableReference();
+                    }
         }
-    }
+        #endregion
+
+        #region TestSpanIndex<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanIndexByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            byte temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                            temp = span[length/2];
 
-    static void FillAllReverseSpanBase()
-    {
-        byte[] a = new byte[Size];
-        Span<byte> s = new Span<byte>(a);
-        for (int i = 0; i < Iterations; i++)
+        }
+
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanIndexString(int length)
         {
-            TestFillAllReverseSpan(s);
+            var array = new string[length];
+            var span = new Span<string>(array);
+            string temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        temp = span[length / 2];
         }
-    }
+        #endregion
+
+        #region TestArrayIndex<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestArrayIndexByte(int length)
+        {
+            var array = new byte[length];
+            byte temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        temp = array[length / 2];
 
-    static void FillAllReverseArrayBase()
-    {
-        byte[] a = new byte[Size];
-        for (int i = 0; i < Iterations; i++)
+        }
+
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestArrayIndexString(int length)
         {
-            TestFillAllReverseArray(a);
+            var array = new string[length];
+            string temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        temp = array[length / 2];
+        }
+        #endregion
+
+        #region TestSpanSlice<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanSliceByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            Span<byte> temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        temp = span.Slice(length / 2);
         }
-    }
 
-    static void QuickSortSpanBase()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
-        Span<int> span = new Span<int>(data);
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanSliceString(int length)
+        {
+            var array = new string[length];
+            var span = new Span<string>(array);
+            Span<string> temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        temp = span.Slice(length / 2);
+        }
+        #endregion
+        
+        #region TestSpanToArray<T>
+        [Benchmark(InnerIterationCount = BaseIterations / 100)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanToArrayByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            byte[] temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        temp = span.ToArray();
+        }
 
-        for (int i = 0; i < Iterations; i++)
+        [Benchmark(InnerIterationCount = BaseIterations / 100)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanToArrayString(int length)
         {
-            Array.Copy(unsortedData, data, Size);
-            TestQuickSortSpan(span);
+            var array = new string[length];
+            var span = new Span<string>(array);
+            string[] temp;
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        temp = span.ToArray();
+        }
+        #endregion
+        
+        #region TestSpanCopyTo<T>
+        [Benchmark(InnerIterationCount = BaseIterations / 10)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanCopyToByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            var destArray = new byte[array.Length];
+            var destination = new Span<byte>(destArray);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span.CopyTo(destination);
         }
-    }
 
-    static void BubbleSortSpanBase()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
-        Span<int> span = new Span<int>(data);
+        [Benchmark(InnerIterationCount = BaseIterations / 100)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanCopyToString(int length)
+        {
+            var array = new string[length];
+            var span = new Span<string>(array);
+            var destArray = new string[array.Length];
+            var destination = new Span<string>(destArray);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span.CopyTo(destination);
+        }
+        #endregion
+
+        #region TestArrayCopyTo<T>
+        [Benchmark(InnerIterationCount = BaseIterations / 10)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestArrayCopyToByte(int length)
+        {
+            var array = new byte[length];
+            var destination = new byte[array.Length];
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        array.CopyTo(destination, 0);
+        }
 
-        for (int i = 0; i < Iterations; i++)
+        [Benchmark(InnerIterationCount = BaseIterations / 100)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestArrayCopyToString(int length)
         {
-            Array.Copy(unsortedData, data, Size);
-            TestBubbleSortSpan(span);
+            var array = new string[length];
+            var destination = new string[array.Length];
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        array.CopyTo(destination, 0);
+        }
+        #endregion
+
+        #region TestSpanFill<T>
+        [Benchmark(InnerIterationCount = BaseIterations * 10)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanFillByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span.Fill(default(byte));
         }
-    }
 
-    static void QuickSortArrayBase()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
+        [Benchmark(InnerIterationCount = BaseIterations / 100)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanFillString(int length)
+        {
+            var array = new string[length];
+            var span = new Span<string>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span.Fill(default(string));
+        }
+        #endregion
+
+        #region TestSpanClear<T>
+        [Benchmark(InnerIterationCount = BaseIterations / 10)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanClearByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span.Clear();
+        }
 
-        for (int i = 0; i < Iterations; i++)
+        [Benchmark(InnerIterationCount = BaseIterations / 10)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanClearString(int length)
         {
-            Array.Copy(unsortedData, data, Size);
-            TestQuickSortArray(data);
+            var array = new string[length];
+            var span = new Span<string>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        span.Clear();
+        }
+        #endregion
+
+        #region TestArrayClear<T>
+        [Benchmark(InnerIterationCount = BaseIterations / 10)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestArrayClearByte(int length)
+        {
+            var array = new byte[length];
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        Array.Clear(array, 0, length);
         }
-    }
 
-    static void BubbleSortArrayBase()
-    {
-        int[] data = new int[Size];
-        int[] unsortedData = GetUnsortedData();
+        [Benchmark(InnerIterationCount = BaseIterations / 10)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestArrayClearString(int length)
+        {
+            var array = new string[length];
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                        Array.Clear(array, 0, length);
+        }
+        #endregion
+
+        #region TestSpanAsBytes<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanAsBytesByte(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                    {
+                        Span<byte> temp = span.AsBytes<byte>();
+                    }
+        }
 
-        for (int i = 0; i < Iterations; i++)
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanAsBytesInt(int length)
         {
-            Array.Copy(unsortedData, data, Size);
-            TestBubbleSortArray(data);
+            var array = new int[length];
+            var span = new Span<int>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                    {
+                        Span<byte> temp = span.AsBytes<int>();
+                    }
+        }
+        #endregion
+
+        #region TestSpanNonPortableCast<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanNonPortableCastFromByteToInt(int length)
+        {
+            var array = new byte[length];
+            var span = new Span<byte>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                    {
+                        Span<int> temp = span.NonPortableCast<byte, int>();
+                    }
         }
-    }
 
-    static double Bench(Action f)
-    {
-        Stopwatch sw = Stopwatch.StartNew();
-        f();
-        sw.Stop();
-        return sw.Elapsed.TotalMilliseconds;
-    }
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanNonPortableCastFromIntToByte(int length)
+        {
+            var array = new int[length];
+            var span = new Span<int>(array);
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                    {
+                        Span<byte> temp = span.NonPortableCast<int, byte>();
+                    }
+        }
+        #endregion
+
+        #region TestSpanSliceStringChar<T>
+        [Benchmark(InnerIterationCount = BaseIterations)]
+        [InlineData(1)]
+        [InlineData(10)]
+        [InlineData(100)]
+        [InlineData(1000)]
+        public static void TestSpanSliceStringChar(int length)
+        {
+            StringBuilder sb = new StringBuilder();
+            Random rand = new Random(42);
+            char[] c = new char[1];
+            for (int i = 0; i < length; i++)
+            {
+                c[0] = (char)rand.Next(32, 126);
+                sb.Append(new string(c));
+            }
+            string s = sb.ToString();
+
+            foreach (var iteration in Benchmark.Iterations)
+                using (iteration.StartMeasurement())
+                    for (int i = 0; i < Benchmark.InnerIterationCount; i++)
+                    {
+                        ReadOnlySpan<char> temp = s.Slice();
+                    }
+        }
+        #endregion
 
-    static IEnumerable<object[]> MakeArgs(params string[] args)
-    {
-        return args.Select(arg => new object[] { arg });
-    }
+        #endregion
+        
+        // EXE-based testing
+        #region EXE-base testing
+        static void FillAllSpanBase()
+        {
+            byte[] a = new byte[Size];
+            Span<byte> s = new Span<byte>(a);
+            for (int i = 0; i < FillAllIterations; i++)
+            {
+                TestFillAllSpan(s);
+            }
+        }
 
-    static IEnumerable<object[]> TestFuncs = MakeArgs(
-        "FillAllSpanBase", "FillAllArrayBase",
-        "FillAllReverseSpanBase", "FillAllReverseArrayBase",
-        "BubbleSortSpanBase", "BubbleSortArrayBase",
-        "QuickSortSpanBase", "QuickSortArrayBase"
-    );
+        static void FillAllArrayBase()
+        {
+            byte[] a = new byte[Size];
+            for (int i = 0; i < FillAllIterations; i++)
+            {
+                TestFillAllArray(a);
+            }
+        }
 
-    static Action LookupFunc(object o)
-    {
-        TypeInfo t = typeof(Tests).GetTypeInfo();
-        MethodInfo m = t.GetDeclaredMethod((string) o);
-        return m.CreateDelegate(typeof(Action)) as Action;
-    }
+        static void FillAllReverseSpanBase()
+        {
+            byte[] a = new byte[Size];
+            Span<byte> s = new Span<byte>(a);
+            for (int i = 0; i < FillAllIterations; i++)
+            {
+                TestFillAllReverseSpan(s);
+            }
+        }
 
-    public static int Main(string[] args)
-    {
-        bool result = true;
+        static void FillAllReverseArrayBase()
+        {
+            byte[] a = new byte[Size];
+            for (int i = 0; i < FillAllIterations; i++)
+            {
+                TestFillAllReverseArray(a);
+            }
+        }
 
-        foreach(object[] o in TestFuncs)
+        static void QuickSortSpanBase()
         {
-            string funcName = (string) o[0];
-            Action func = LookupFunc(funcName);
-            double timeInMs = Bench(func);
-            Console.WriteLine("{0}: {1}ms", funcName, timeInMs);
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
+            Span<int> span = new Span<int>(data);
+
+            for (int i = 0; i < QuickSortIterations; i++)
+            {
+                Array.Copy(unsortedData, data, Size);
+                TestQuickSortSpan(span);
+            }
         }
 
-        return (result ? 100 : -1);
-    }
-}
+        static void BubbleSortSpanBase()
+        {
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
+            Span<int> span = new Span<int>(data);
+
+            for (int i = 0; i < BubbleSortIterations; i++)
+            {
+                Array.Copy(unsortedData, data, Size);
+                TestBubbleSortSpan(span);
+            }
+        }
+
+        static void QuickSortArrayBase()
+        {
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
 
+            for (int i = 0; i < QuickSortIterations; i++)
+            {
+                Array.Copy(unsortedData, data, Size);
+                TestQuickSortArray(data);
+            }
+        }
+
+        static void BubbleSortArrayBase()
+        {
+            int[] data = new int[Size];
+            int[] unsortedData = GetUnsortedData();
+
+            for (int i = 0; i < BubbleSortIterations; i++)
+            {
+                Array.Copy(unsortedData, data, Size);
+                TestBubbleSortArray(data);
+            }
+        }
+        #endregion
+
+        static double Bench(Action f)
+        {
+            Stopwatch sw = Stopwatch.StartNew();
+            f();
+            sw.Stop();
+            return sw.Elapsed.TotalMilliseconds;
+        }
+
+        static IEnumerable<object[]> MakeArgs(params string[] args)
+        {
+            return args.Select(arg => new object[] { arg });
+        }
+
+        static IEnumerable<object[]> TestFuncs = MakeArgs(
+            "FillAllSpanBase", "FillAllArrayBase",
+            "FillAllReverseSpanBase", "FillAllReverseArrayBase",
+            "BubbleSortSpanBase", "BubbleSortArrayBase",
+            "QuickSortSpanBase", "QuickSortArrayBase"
+        );
+
+        static Action LookupFunc(object o)
+        {
+            TypeInfo t = typeof(SpanBench).GetTypeInfo();
+            MethodInfo m = t.GetDeclaredMethod((string) o);
+            return m.CreateDelegate(typeof(Action)) as Action;
+        }
+
+        public static int Main(string[] args)
+        {
+            bool result = true;
+
+            foreach(object[] o in TestFuncs)
+            {
+                string funcName = (string) o[0];
+                Action func = LookupFunc(funcName);
+                double timeInMs = Bench(func);
+                Console.WriteLine("{0}: {1}ms", funcName, timeInMs);
+            }
+            
+            return (result ? 100 : -1);
+        }
+    }
+}
\ No newline at end of file
diff --git a/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.csproj b/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.csproj
index e932acf2a2..ba240107ba 100644
--- a/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.csproj
+++ b/tests/src/JIT/Performance/CodeQuality/Span/SpanBench.csproj
@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <!-- Always use latest Roslyn compiler -->
+  <Import Project="..\..\..\..\..\..\Tools\net45\roslyn\build\Microsoft.Net.Compilers.props"/>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>