Add FileCheck test for elided bounds checks

src/tests/JIT/opt/RangeChecks/ElidedBoundsChecks.cs

@@ -0,0 +1,94 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.CompilerServices;
+using Xunit;
+
+public class ElidedBoundsChecks
+{
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    static int ComplexBinaryOperators(byte inData)
+    {
+        // X64-NOT: CORINFO_HELP_RNGCHKFAIL
+        // ARM64-NOT: CORINFO_HELP_RNGCHKFAIL
+        ReadOnlySpan<byte> base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="u8;
+        return base64[((inData & 0x03) << 4) | ((inData & 0xf0) >> 4)];
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    static bool LastCharCheck(string prefix, string path)
+    {
+        // X64-NOT: CORINFO_HELP_RNGCHKFAIL
+        // ARM64-NOT: CORINFO_HELP_RNGCHKFAIL
+        if (prefix.Length < path.Length)
+            return (path[prefix.Length] == '/');
+        return false;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    static nint CountDigits(ulong value)
+    {
+        // X64-NOT: CORINFO_HELP_RNGCHKFAIL
+        // ARM64-NOT: CORINFO_HELP_RNGCHKFAIL
+        ReadOnlySpan<byte> log2ToPow10 =
+        [
+            1,  1,  1,  2,  2,  2,  3,  3,  3,  4,  4,  4,  4,  5,  5,  5,
+            6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  9,  9,  9,  10, 10, 10,
+            10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15,
+            15, 16, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 19, 20
+        ];
+        return log2ToPow10[(int)ulong.Log2(value)];
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    static byte AndByConst(int i)
+    {
+        // X64-NOT: CORINFO_HELP_RNGCHKFAIL
+        // ARM64-NOT: CORINFO_HELP_RNGCHKFAIL
+        ReadOnlySpan<byte> span = new byte[] { 1, 2, 3, 4 };
+        return span[i & 2];
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    static byte AndByLength(int i)
+    {
+        // X64-NOT: CORINFO_HELP_RNGCHKFAIL
+        // ARM64-NOT: CORINFO_HELP_RNGCHKFAIL
+        ReadOnlySpan<byte> span = new byte[] { 1, 2, 3, 4 };
+        return span[i & (span.Length - 1)];
+    }
+
+    [Fact]
+    public static int TestEntryPoint()
+    {
+        if (ComplexBinaryOperators(0xFF) != (byte)'/')
+            return 0;
+
+        if (LastCharCheck("abc", "abcd") != false)
+            return 0;
+
+        if (LastCharCheck("abc", "abc/def") != true)
+            return 0;
+
+        if (CountDigits(1) != 1)
+            return 0;
+
+        if (CountDigits(10000000000000000000UL) != 20)
+            return 0;
+
+        if (AndByConst(0) != 1)
+            return 0;
+
+        if (AndByConst(255) != 3)
+            return 0;
+
+        if (AndByLength(0) != 1)
+            return 0;
+
+        if (AndByLength(255) != 4)
+            return 0;
+
+        return 100;
+    }
+}

src/tests/JIT/opt/RangeChecks/ElidedBoundsChecks.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <!-- Needed for CLRTestEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+  </PropertyGroup>
+  <PropertyGroup>
+    <DebugType>None</DebugType>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs">
+      <HasDisasmCheck>true</HasDisasmCheck>
+    </Compile>
+
+    <CLRTestEnvironmentVariable Include="DOTNET_TieredCompilation" Value="0" />
+    <CLRTestEnvironmentVariable Include="DOTNET_JITMinOpts" Value="0" />
+  </ItemGroup>
+</Project>