1 files changed, 24 insertions, 0 deletions
diff --git a/source/slang/diff.meta.slang b/source/slang/diff.meta.slang
index ce0e72d34..423b6bfd0 100644
--- a/source/slang/diff.meta.slang
+++ b/source/slang/diff.meta.slang
@@ -25,6 +25,30 @@ attribute_syntax [DerivativeMember(memberName)] : DerivativeMemberAttribute;
 __attributeTarget(FunctionDeclBase)
 attribute_syntax [NoDiffThis] : NoDiffThisAttribute;
 
+// A 'none-type' that acts as a run-time sentinel for zero differentials.
+public struct NullDifferential : IDifferentiable
+{ 
+    // for now, we'll use at least one field to make sure the type is non-empty
+    uint dummy;
+    typedef NullDifferential Differential;
+
+    [Differentiable]
+    [ForceInline]
+    static Differential dzero() { return { 0 }; }
+
+    [Differentiable]
+    [ForceInline]
+    static Differential dadd(Differential, Differential) { return { 0 }; }
+
+    [Differentiable]
+    [ForceInline]
+    static Differential dmul<T: __BuiltinRealType>(T, Differential) { return { 0 }; }
+};
+
+// Existential check for null differential type
+__intrinsic_op($(kIROp_IsDifferentialNull))
+bool isDifferentialNull(IDifferentiable obj);
+
 /// Represents a GPU view of a tensor.
 __generic<T>
 __magic_type(TensorViewType)