Replace string.Compare == 0 patterns with Equals/StartsWith/AsSpan calls

src/coreclr/tools/Common/TypeSystem/Ecma/EcmaModule.Sorting.cs

@@ -36,7 +36,7 @@ public int CompareTo(EcmaModule other)
                 // Multi-module assembly: compare two modules that are part of same assembly
                 string thisName = _metadataReader.GetString(_metadataReader.GetModuleDefinition().Name);
                 string otherName = other._metadataReader.GetString(other._metadataReader.GetModuleDefinition().Name);
-                Debug.Assert(StringComparer.Ordinal.Compare(thisName, otherName) != 0);
+                Debug.Assert(!StringComparer.Ordinal.Equals(thisName, otherName));
                 return StringComparer.Ordinal.Compare(thisName, otherName);
             }
         }

src/coreclr/tools/aot/ILCompiler.Trimming.Tests/TestCasesRunner/AssemblyQualifiedToken.cs

@@ -51,7 +51,7 @@ public AssemblyQualifiedToken(IMemberDefinition member) =>
         public override int GetHashCode() => AssemblyName == null ? 0 : AssemblyName.GetHashCode() ^ Token.GetHashCode();
         public override string ToString() => $"{AssemblyName}: {Token}";
         public bool Equals(AssemblyQualifiedToken other) =>
-            string.CompareOrdinal(AssemblyName, other.AssemblyName) == 0 && Token == other.Token;
+            AssemblyName == other.AssemblyName && Token == other.Token;
         public override bool Equals([NotNullWhen(true)] object? obj) => ((AssemblyQualifiedToken?)obj)?.Equals(this) == true;
 
         public bool IsNil => AssemblyName == null;

src/coreclr/tools/dotnet-pgo/Program.cs

@@ -207,8 +207,8 @@ internal static void UnZipIfNecessary(ref string inputFileName, TextWriter log)
             }
 
             var extension = Path.GetExtension(inputFileName);
-            if (string.Compare(extension, ".zip", StringComparison.OrdinalIgnoreCase) == 0 ||
-                string.Compare(extension, ".vspx", StringComparison.OrdinalIgnoreCase) == 0)
+            if (string.Equals(extension, ".zip", StringComparison.OrdinalIgnoreCase) ||
+                string.Equals(extension, ".vspx", StringComparison.OrdinalIgnoreCase))
             {
                 string unzipedEtlFile;
                 if (inputFileName.EndsWith(".etl.zip", StringComparison.OrdinalIgnoreCase))

src/libraries/Common/src/System/Net/CredentialCacheKey.cs

@@ -70,7 +70,7 @@ private bool IsPrefix(Uri uri, int prefixLen)
                 return false;
             }
 
-            return string.Compare(uri.AbsolutePath, 0, uriPrefix.AbsolutePath, 0, UriPrefixLength, StringComparison.OrdinalIgnoreCase) == 0;
+            return uri.AbsolutePath.AsSpan(0, UriPrefixLength).Equals(uriPrefix.AbsolutePath.AsSpan(0, UriPrefixLength), StringComparison.OrdinalIgnoreCase);
         }
 
         public override int GetHashCode() =>

src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/ComponentResourceManager.cs

@@ -141,19 +141,9 @@ private void ApplyResources(object value, Type typeFromValue, string objectName,
                 // See if this key matches our object.
                 string key = kvp.Key;
 
-                if (IgnoreCase)
+                if (!key.StartsWith(objectName, IgnoreCase ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal))
                 {
-                    if (string.Compare(key, 0, objectName, 0, objectName.Length, StringComparison.OrdinalIgnoreCase) != 0)
-                    {
-                        continue;
-                    }
-                }
-                else
-                {
-                    if (string.CompareOrdinal(key, 0, objectName, 0, objectName.Length) != 0)
-                    {
-                        continue;
-                    }
+                    continue;
                 }
 
                 // Character after objectName.Length should be a "." or a '-', or else we should continue.

src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/Design/DesignerOptionService.cs

@@ -229,7 +229,7 @@ public DesignerOptionCollection? this[string name]
                     EnsurePopulated();
                     foreach (DesignerOptionCollection child in _children)
                     {
-                        if (string.Compare(child.Name, name, true, CultureInfo.InvariantCulture) == 0)
+                        if (string.Equals(child.Name, name, StringComparison.InvariantCultureIgnoreCase))
                         {
                             return child;
                         }

src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/ReflectPropertyDescriptor.cs

@@ -951,7 +951,7 @@ protected override void FillAttributes(IList attributes)
         internal void OnINotifyPropertyChanged(object? component, PropertyChangedEventArgs e)
         {
             if (string.IsNullOrEmpty(e.PropertyName) ||
-                string.Compare(e.PropertyName, Name, true, CultureInfo.InvariantCulture) == 0)
+                string.Equals(e.PropertyName, Name, StringComparison.InvariantCultureIgnoreCase))
             {
                 OnValueChanged(component, e);
             }

src/libraries/System.Configuration.ConfigurationManager/src/System/Configuration/AppSettingsReader.cs

@@ -84,7 +84,7 @@ private static int GetNoneNesting(string val)
                 {
                     count++;
                 }
-                if (count > 0 && string.Compare(NullString, 0, val, count, len - 2 * count, StringComparison.Ordinal) != 0)
+                if (count > 0 && !val.AsSpan(count, len - 2 * count).Equals(NullString, StringComparison.Ordinal))
                 {
                     // the stuff between the parens is not "None"
                     count = 0;

src/libraries/System.Configuration.ConfigurationManager/src/System/Configuration/StringUtil.cs

@@ -17,14 +17,14 @@ internal static bool EqualsIgnoreCase(string s1, string s2)
 
         internal static bool StartsWithOrdinal(string s1, string s2)
         {
-            if (s2 == null) return false;
-            return 0 == string.Compare(s1, 0, s2, 0, s2.Length, StringComparison.Ordinal);
+            if (s1 is null || s2 is null) return false;
+            return s1.StartsWith(s2, StringComparison.Ordinal);
         }
 
         internal static bool StartsWithOrdinalIgnoreCase(string s1, string s2)
         {
-            if (s2 == null) return false;
-            return 0 == string.Compare(s1, 0, s2, 0, s2.Length, StringComparison.OrdinalIgnoreCase);
+            if (s1 is null || s2 is null) return false;
+            return s1.StartsWith(s2, StringComparison.OrdinalIgnoreCase);
         }
 
         internal static string[] ObjectArrayToStringArray(object[] objectArray)

src/libraries/System.Configuration.ConfigurationManager/src/System/Configuration/UrlPath.cs

@@ -36,7 +36,7 @@ internal static bool IsEqualOrSubdirectory(string dir, string subdir)
             if (lSubdir < lDir)
                 return false;
 
-            if (string.Compare(dir, 0, subdir, 0, lDir, StringComparison.OrdinalIgnoreCase) != 0)
+            if (!dir.AsSpan(0, lDir).Equals(subdir.AsSpan(0, lDir), StringComparison.OrdinalIgnoreCase))
                 return false;
 
             // Check subdir that character following length of dir is a backslash
@@ -84,7 +84,7 @@ private static bool IsEqualOrSubpathImpl(string path, string subpath, bool exclu
             if (excludeEqual && (lSubpath == lPath))
                 return false;
 
-            if (string.Compare(path, 0, subpath, 0, lPath, StringComparison.OrdinalIgnoreCase) != 0)
+            if (!path.AsSpan(0, lPath).Equals(subpath.AsSpan(0, lPath), StringComparison.OrdinalIgnoreCase))
                 return false;
 
             // Check subpath that character following length of path is a slash

src/libraries/System.Data.Common/src/System/Data/DataTable.cs

@@ -3717,11 +3717,11 @@ internal IndexField[] ParseSortString(string? sortString)
                     // handle ASC and DESC.
                     int length = current.Length;
                     bool descending = false;
-                    if (length >= 5 && string.Compare(current, length - 4, " ASC", 0, 4, StringComparison.OrdinalIgnoreCase) == 0)
+                    if (length >= 5 && current.EndsWith(" ASC", StringComparison.OrdinalIgnoreCase))
                     {
                         current = current.AsSpan(0, length - 4).Trim().ToString();
                     }
-                    else if (length >= 6 && string.Compare(current, length - 5, " DESC", 0, 5, StringComparison.OrdinalIgnoreCase) == 0)
+                    else if (length >= 6 && current.EndsWith(" DESC", StringComparison.OrdinalIgnoreCase))
                     {
                         descending = true;
                         current = current.AsSpan(0, length - 5).Trim().ToString();

src/libraries/System.Data.Odbc/src/System/Data/Odbc/OdbcUtils.cs

@@ -540,7 +540,7 @@ internal bool StartsWith(string tokenString)
                 return false;
             }
 
-            if (0 == string.Compare(_sqlstatement, tempidx, tokenString, 0, tokenString.Length, StringComparison.OrdinalIgnoreCase))
+            if (_sqlstatement.AsSpan(tempidx).StartsWith(tokenString, StringComparison.OrdinalIgnoreCase))
             {
                 // Reset current position and token
                 _idx = 0;

src/libraries/System.Diagnostics.EventLog/src/System/Diagnostics/EventLog.cs

@@ -460,7 +460,7 @@ public static void DeleteEventSource(string source, string machineName)
                     // The reason: each log registry key must always contain subkey (i.e. source) with the same name.
                     string keyname = key.Name;
                     int index = keyname.LastIndexOf('\\');
-                    if (string.Compare(keyname, index + 1, source, 0, keyname.Length - index, StringComparison.Ordinal) == 0)
+                    if (keyname.AsSpan(index + 1).Equals(source, StringComparison.Ordinal))
                         throw new InvalidOperationException(SR.Format(SR.CannotDeleteEqualSource, source));
                 }
 

src/libraries/System.DirectoryServices/src/System/DirectoryServices/ActiveDirectory/Utils.cs

@@ -1542,7 +1542,7 @@ internal static ArrayList GetReplicaList(DirectoryContext context, string? parti
                                             // multivalues attribute we can stop here.
                                             foundPartitionEntry = true;
 
-                                            if (string.Compare(dnString, 10, "0", 0, 1, StringComparison.OrdinalIgnoreCase) == 0)
+                                            if (dnString[10] == '0')
                                             {
                                                 // this server has the partition fully instantiated
                                                 ntdsaNames.Add(ntdsaName);
@@ -1648,7 +1648,7 @@ internal static ArrayList GetReplicaList(DirectoryContext context, string? parti
                                         // find the property name with the range info
                                         foreach (string property in res.Properties.PropertyNames)
                                         {
-                                            if (string.Compare(property, 0, PropertyManager.MsDSHasInstantiatedNCs, 0, PropertyManager.MsDSHasInstantiatedNCs.Length, StringComparison.OrdinalIgnoreCase) == 0)
+                                            if (property.AsSpan().StartsWith(PropertyManager.MsDSHasInstantiatedNCs, StringComparison.OrdinalIgnoreCase))
                                             {
                                                 propertyName = property;
                                                 break;
@@ -1677,7 +1677,7 @@ internal static ArrayList GetReplicaList(DirectoryContext context, string? parti
                                         {
                                             foundPartitionEntry = true;
 
-                                            if (string.Compare(dnString, 10, "0", 0, 1, StringComparison.OrdinalIgnoreCase) == 0)
+                                            if (dnString[10] == '0')
                                             {
                                                 ntdsaNames.Add(ntdsaName);
                                                 if (isADAM)