From fdff30b39bb2cee030e7f5aa3b163cf93d861d0b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 29 Jan 2026 21:57:46 +0000
Subject: [PATCH 1/2] Initial plan


From 9394c9ec768867e7bdd5a06619cab5c141f631fd Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 29 Jan 2026 22:02:45 +0000
Subject: [PATCH 2/2] Enable cached interface dispatch support by default on
 non-jit platforms

Co-authored-by: davidwrighton <10779849+davidwrighton@users.noreply.github.com>
---
 src/coreclr/tools/aot/crossgen2/Crossgen2RootCommand.cs   | 2 +-
 src/coreclr/tools/aot/crossgen2/Program.cs                | 2 +-
 src/coreclr/tools/aot/crossgen2/Properties/Resources.resx | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/coreclr/tools/aot/crossgen2/Crossgen2RootCommand.cs b/src/coreclr/tools/aot/crossgen2/Crossgen2RootCommand.cs
index b63e33f17ac23b..c31f7175e0b7c8 100644
--- a/src/coreclr/tools/aot/crossgen2/Crossgen2RootCommand.cs
+++ b/src/coreclr/tools/aot/crossgen2/Crossgen2RootCommand.cs
@@ -42,7 +42,7 @@ internal class Crossgen2RootCommand : RootCommand
             new("--optimize-space", "--Os") { Description = SR.OptimizeSpaceOption };
         public Option<bool> OptimizeTime { get; } =
             new("--optimize-time", "--Ot") { Description = SR.OptimizeSpeedOption };
-        public Option<bool> EnableCachedInterfaceDispatchSupport { get; } =
+        public Option<bool?> EnableCachedInterfaceDispatchSupport { get; } =
             new("--enable-cached-interface-dispatch-support", "--CID") { Description = SR.EnableCachedInterfaceDispatchSupport };
         public Option<TypeValidationRule> TypeValidation { get; } =
             new("--type-validation") { DefaultValueFactory = _ => TypeValidationRule.Automatic, Description = SR.TypeValidation, HelpName = "arg" };
diff --git a/src/coreclr/tools/aot/crossgen2/Program.cs b/src/coreclr/tools/aot/crossgen2/Program.cs
index ffa238e9e4388a..2ac14e471e8448 100644
--- a/src/coreclr/tools/aot/crossgen2/Program.cs
+++ b/src/coreclr/tools/aot/crossgen2/Program.cs
@@ -623,7 +623,7 @@ private void RunSingleCompilation(Dictionary<string, string> inFilePaths, Instru
                     nodeFactoryFlags.TypeValidation = Get(_command.TypeValidation);
                     nodeFactoryFlags.DeterminismStress = Get(_command.DeterminismStress);
                     nodeFactoryFlags.PrintReproArgs = Get(_command.PrintReproInstructions);
-                    nodeFactoryFlags.EnableCachedInterfaceDispatchSupport = Get(_command.EnableCachedInterfaceDispatchSupport);
+                    nodeFactoryFlags.EnableCachedInterfaceDispatchSupport = Get(_command.EnableCachedInterfaceDispatchSupport) ?? !typeSystemContext.TargetAllowsRuntimeCodeGeneration;
 
                     builder
                         .UseMapFile(Get(_command.Map))
diff --git a/src/coreclr/tools/aot/crossgen2/Properties/Resources.resx b/src/coreclr/tools/aot/crossgen2/Properties/Resources.resx
index e1f59a69a5cff7..ca30cc9a5e31d0 100644
--- a/src/coreclr/tools/aot/crossgen2/Properties/Resources.resx
+++ b/src/coreclr/tools/aot/crossgen2/Properties/Resources.resx
@@ -424,7 +424,7 @@
     <value>Number of nested occurrences of a potentially cyclic generic type to cut off</value>
   </data>
   <data name="EnableCachedInterfaceDispatchSupport" xml:space="preserve">
-    <value>Enable support for cached interface dispatch</value>
+    <value>Enable support for cached interface dispatch. Default is true on platforms which do not support runtime code generation</value>
   </data>
   <data name="OutputFormat" xml:space="preserve">
     <value>Target output format for the ReadyToRun image</value>