diff --git a/src/include/osl_pvt.h b/src/include/osl_pvt.h
index f36e3d280..526d838e5 100644
--- a/src/include/osl_pvt.h
+++ b/src/include/osl_pvt.h
@@ -389,6 +389,13 @@ class TypeSpec {
     /// to the type.
     std::string code_from_type() const;
 
+    /// Return the type code used to build mangled osl_* runtime function
+    /// names (e.g. "f" for float, "v" for any triple, "m" for matrix,
+    /// "s" for string, "i" for int).  Unlike code_from_type(), all triple
+    /// subtypes (color, point, vector, normal) collapse to "v".  When
+    /// derivs is true, float and triple types are prefixed with "d".
+    std::string runtime_typecode(bool derivs = false) const;
+
     /// Take a type code string (possibly containing many types)
     /// and turn it into a human-readable string.
     static std::string typelist_from_code(const char* code);
@@ -541,6 +548,13 @@ class Symbol {
     /// render time should always use the unmangled version for clarity.
     string_view unmangled() const;
 
+    /// Return the runtime type code string for this symbol's type, suitable
+    /// for building mangled osl_* function names.  See TypeSpec::runtime_typecode().
+    std::string arg_typecode(bool derivs = false) const
+    {
+        return typespec().runtime_typecode(derivs);
+    }
+
     /// Data type of this symbol.
     ///
     const TypeSpec& typespec() const { return m_typespec; }
diff --git a/src/liboslexec/llvm_gen.cpp b/src/liboslexec/llvm_gen.cpp
index 3b9e788e6..c75a687e0 100644
--- a/src/liboslexec/llvm_gen.cpp
+++ b/src/liboslexec/llvm_gen.cpp
@@ -2359,21 +2359,8 @@ LLVMGEN(llvm_gen_generic)
     std::string name = std::string("osl_") + op.opname().string() + "_";
     for (int i = 0; i < op.nargs(); ++i) {
         Symbol* s(rop.opargsym(op, i));
-        if (any_deriv_args && Result.has_derivs() && s->has_derivs()
-            && !s->typespec().is_matrix())
-            name += "d";
-        if (s->typespec().is_float())
-            name += "f";
-        else if (s->typespec().is_triple())
-            name += "v";
-        else if (s->typespec().is_matrix())
-            name += "m";
-        else if (s->typespec().is_string())
-            name += "s";
-        else if (s->typespec().is_int())
-            name += "i";
-        else
-            OSL_ASSERT(0);
+        bool derivs = any_deriv_args && Result.has_derivs() && s->has_derivs();
+        name += s->arg_typecode(derivs);
     }
 
     if (!Result.has_derivs() || !any_deriv_args) {
@@ -3068,31 +3055,6 @@ LLVMGEN(llvm_gen_trace)
 
 
 
-static std::string
-arg_typecode(Symbol* sym, bool derivs)
-{
-    const TypeSpec& t(sym->typespec());
-    if (t.is_int())
-        return "i";
-    else if (t.is_matrix())
-        return "m";
-    else if (t.is_string())
-        return "s";
-
-    std::string name;
-    if (derivs)
-        name = "d";
-    if (t.is_float())
-        name += "f";
-    else if (t.is_triple())
-        name += "v";
-    else
-        OSL_ASSERT(0);
-    return name;
-}
-
-
-
 static llvm::Value*
 llvm_gen_noise_options(BackendLLVM& rop, int opnum, int first_optional_arg)
 {
@@ -3265,7 +3227,7 @@ LLVMGEN(llvm_gen_noise)
     }
 
     std::string funcname = "osl_" + name.string() + "_"
-                           + arg_typecode(&Result, derivs);
+                           + Result.arg_typecode(derivs);
     llvm::Value* args[10];
     int nargs = 0;
     if (pass_name) {
@@ -3280,18 +3242,18 @@ LLVMGEN(llvm_gen_noise)
         } else
             args[nargs++] = rop.llvm_void_ptr(Result);
     }
-    funcname += arg_typecode(S, derivs);
+    funcname += S->arg_typecode(derivs);
     args[nargs++] = rop.llvm_load_arg(*S, derivs);
     if (T) {
-        funcname += arg_typecode(T, derivs);
+        funcname += T->arg_typecode(derivs);
         args[nargs++] = rop.llvm_load_arg(*T, derivs);
     }
 
     if (periodic) {
-        funcname += arg_typecode(Sper, false /* no derivs */);
+        funcname += Sper->arg_typecode(false);
         args[nargs++] = rop.llvm_load_arg(*Sper, false);
         if (Tper) {
-            funcname += arg_typecode(Tper, false /* no derivs */);
+            funcname += Tper->arg_typecode(false);
             args[nargs++] = rop.llvm_load_arg(*Tper, false);
         }
     }
diff --git a/src/liboslexec/typespec.cpp b/src/liboslexec/typespec.cpp
index 0722585f7..59f550e7d 100644
--- a/src/liboslexec/typespec.cpp
+++ b/src/liboslexec/typespec.cpp
@@ -259,6 +259,22 @@ TypeSpec::code_from_type() const
 
 
 
+std::string
+TypeSpec::runtime_typecode(bool derivs) const
+{
+    // Reuse code_from_type() for the base char, then collapse all triple
+    // subtypes (c/p/n) to 'v' since the runtime ABI does not distinguish them.
+    OSL_DASSERT(!is_array() && !is_structure() && !is_closure());
+    std::string code = code_from_type();
+    if (code == "c" || code == "p" || code == "n")
+        code = "v";
+    if (derivs && (code == "f" || code == "v"))
+        code = "d" + code;
+    return code;
+}
+
+
+
 void
 TypeSpec::typespecs_from_codes(const char* code, std::vector<TypeSpec>& types)
 {