Intrinsify default Comparer<T> and EqualityComparer<T> creation in R2R

src/coreclr/System.Private.CoreLib/src/System/Collections/Generic/Comparer.CoreCLR.cs

@@ -7,9 +7,13 @@ namespace System.Collections.Generic
 {
     public abstract partial class Comparer<T> : IComparer, IComparer<T>
     {
+        // This method is special cased in R2R, with its implementation replaced by IL helper
+        [Intrinsic]
+        private static Comparer<T> Create() => (Comparer<T>)ComparerHelpers.CreateDefaultComparer(typeof(T));
+
         // To minimize generic instantiation overhead of creating the comparer per type, we keep the generic portion of the code as small
         // as possible and define most of the creation logic in a non-generic class.
-        public static Comparer<T> Default { [Intrinsic] get; } = (Comparer<T>)ComparerHelpers.CreateDefaultComparer(typeof(T));
+        public static Comparer<T> Default { [Intrinsic] get; } = Create();
     }
 
     internal sealed partial class EnumComparer<T> : Comparer<T> where T : struct, Enum

src/coreclr/System.Private.CoreLib/src/System/Collections/Generic/EqualityComparer.CoreCLR.cs

@@ -8,9 +8,13 @@ namespace System.Collections.Generic
 {
     public abstract partial class EqualityComparer<T> : IEqualityComparer, IEqualityComparer<T>
     {
+        // This method is special cased in R2R, with its implementation replaced by IL helper
+        [Intrinsic]
+        private static EqualityComparer<T> Create() => (EqualityComparer<T>)ComparerHelpers.CreateDefaultEqualityComparer(typeof(T));
+
         // To minimize generic instantiation overhead of creating the comparer per type, we keep the generic portion of the code as small
         // as possible and define most of the creation logic in a non-generic class.
-        public static EqualityComparer<T> Default { [Intrinsic] get; } = (EqualityComparer<T>)ComparerHelpers.CreateDefaultEqualityComparer(typeof(T));
+        public static EqualityComparer<T> Default { [Intrinsic] get; } = Create();
     }
 
     public sealed partial class GenericEqualityComparer<T> : EqualityComparer<T> where T : IEquatable<T>?

src/coreclr/tools/aot/ILCompiler.ReadyToRun/IL/ReadyToRunILProvider.cs

@@ -120,6 +120,20 @@ private MethodIL TryGetPerInstantiationIntrinsicMethodIL(MethodDesc method)
                 return InterlockedIntrinsics.EmitIL(_compilationModuleGroup, method);
             }
 
+            if (mdType.Namespace.SequenceEqual("System.Collections.Generic"u8))
+            {
+                if (mdType.Name.SequenceEqual("Comparer`1"u8))
+                {
+                    if (method.Name.SequenceEqual("Create"u8))
+                        return ComparerIntrinsics.EmitComparerCreate(method);
+                }
+                else if (mdType.Name.SequenceEqual("EqualityComparer`1"u8))
+                {
+                    if (method.Name.SequenceEqual("Create"u8))
+                        return ComparerIntrinsics.EmitEqualityComparerCreate(method);
+                }
+            }
+
             return null;
         }