diff --git a/loopy/codegen/expression.py b/loopy/codegen/expression.py
index a270944016c9c69163be5a94df7e9fc7cfbd4feb..3ccb5d1edc2874953ee4808d649b9649d9317472 100644
--- a/loopy/codegen/expression.py
+++ b/loopy/codegen/expression.py
@@ -52,7 +52,14 @@ class TypeInferenceMapper(CombineMapper):
         if isinstance(expr.function, Variable):
             name = expr.function.name
             arg_dtypes = tuple(self.rec(par) for par in expr.parameters)
-            return self.kernel.get_function_result_dtype(name, arg_dtypes)
+            for rdg in self.kernel.function_result_dtype_getters:
+                result = rdg(name, arg_dtypes)
+                if result is not None:
+                    return result
+
+            raise RuntimeError("no type inference information on "
+                    "function '%s'" % name)
+
         else:
             return CombineMapper.map_call(self, expr)
 
diff --git a/loopy/kernel.py b/loopy/kernel.py
index d74a9d7ba8f0713b00940a9e91b76fd331752dc2..a1cfe80596513e9666f32d5f38246711fccd3c92 100644
--- a/loopy/kernel.py
+++ b/loopy/kernel.py
@@ -495,9 +495,8 @@ def _default_get_function_result_dtype(name, arg_dtypes):
     if len(arg_dtypes) == 1:
         dtype, = arg_dtypes
         return dtype
-    else:
-        raise RuntimeError("no type inference information on "
-                "function '%s'" % name)
+
+    return None
 
 class LoopKernel(Record):
     """
@@ -526,7 +525,8 @@ class LoopKernel(Record):
     :ivar applied_substitutions: A list of past substitution dictionaries that
         were applied to the kernel. These are stored so that they may be repeated
         on expressions the user specifies later.
-    :ivar get_function_result_dtype:
+    :ivar function_result_dtype_getters: list of functions of signature (name, arg_dtypes)
+        returning the result dtype of that function.
 
     :ivar cache_manager:
 
@@ -545,7 +545,7 @@ class LoopKernel(Record):
             iname_to_tag={}, iname_to_tag_requests=None, substitutions={},
             cache_manager=None, lowest_priority_inames=[], breakable_inames=set(),
             applied_substitutions=[],
-            get_function_result_dtype=_default_get_function_result_dtype):
+            function_result_dtype_getters=[_default_get_function_result_dtype]):
         """
         :arg domain: a :class:`islpy.BasicSet`, or a string parseable to a basic set by the isl.
             Example: "{[i,j]: 0<=i < 10 and 0<= j < 9}"
@@ -750,7 +750,7 @@ class LoopKernel(Record):
                 lowest_priority_inames=lowest_priority_inames,
                 breakable_inames=breakable_inames,
                 applied_substitutions=applied_substitutions,
-                get_function_result_dtype=get_function_result_dtype)
+                function_result_dtype_getters=function_result_dtype_getters)
 
     def make_unique_instruction_id(self, insns=None, based_on="insn", extra_used_ids=set()):
         if insns is None:
@@ -973,7 +973,7 @@ class LoopKernel(Record):
         if not all_inames_by_insns <= self.all_inames():
             raise RuntimeError("inames collected from instructions (%s) "
                     "that are not present in domain (%s)"
-                    % (", ".join(sorted(all_inames_by_insns)), 
+                    % (", ".join(sorted(all_inames_by_insns)),
                         ", ".join(sorted(self.all_inames()))))
 
         global_sizes = {}