diff --git a/Makefile b/Makefile
index 0b01324dc..abb079f56 100644
--- a/Makefile
+++ b/Makefile
@@ -84,6 +84,10 @@ benchmark: release
 	$(V) $(MAKE) -f util/wren.mk api_test
 	$(V) ./util/benchmark.py -l wren $(suite)
 
+benchmark_baseline: release
+	$(V) $(MAKE) -f util/wren.mk api_test
+	$(V) ./util/benchmark.py --generate-baseline
+
 unit_test:
 	$(V) $(MAKE) -f util/wren.mk MODE=debug unit_test
 	$(V) ./build/debug/test/unit_wrend
diff --git a/src/vm/wren_core.c b/src/vm/wren_core.c
index 56b6222c7..445038b9a 100644
--- a/src/vm/wren_core.c
+++ b/src/vm/wren_core.c
@@ -240,6 +240,44 @@ DEF_PRIMITIVE(fn_arity)
   RETURN_NUM(AS_CLOSURE(args[0])->fn->arity);
 }
 
+static void call(WrenVM* vm, Value* args, int numArgs)
+{
+  // We only care about missing arguments, not extras.
+  if (AS_CLOSURE(args[0])->fn->arity > numArgs)
+  {
+    vm->fiber->error = CONST_STRING(vm, "Function expects more arguments.");
+    return;
+  }
+  
+  // +1 to include the function itself.
+  wrenCallFunction(vm, vm->fiber, AS_CLOSURE(args[0]), numArgs + 1);
+}
+
+#define DEF_FN_CALL(numArgs) \
+    DEF_PRIMITIVE(fn_call##numArgs) \
+    { \
+      call(vm, args, numArgs); \
+      return false; \
+    } \
+
+DEF_FN_CALL(0)
+DEF_FN_CALL(1)
+DEF_FN_CALL(2)
+DEF_FN_CALL(3)
+DEF_FN_CALL(4)
+DEF_FN_CALL(5)
+DEF_FN_CALL(6)
+DEF_FN_CALL(7)
+DEF_FN_CALL(8)
+DEF_FN_CALL(9)
+DEF_FN_CALL(10)
+DEF_FN_CALL(11)
+DEF_FN_CALL(12)
+DEF_FN_CALL(13)
+DEF_FN_CALL(14)
+DEF_FN_CALL(15)
+DEF_FN_CALL(16)
+
 DEF_PRIMITIVE(fn_toString)
 {
   RETURN_VAL(CONST_STRING(vm, "<fn>"));
@@ -1097,19 +1135,6 @@ static ObjClass* defineClass(WrenVM* vm, ObjModule* module, const char* name)
   return classObj;
 }
 
-// Defines one of the overloads of the special "call(...)" method on Fn.
-//
-// These methods have their own unique method type to handle pushing the
-// function onto the callstack and checking its arity.
-static void fnCall(WrenVM* vm, const char* signature)
-{
-  int symbol = wrenSymbolTableEnsure(vm, &vm->methodNames, signature,
-                                     strlen(signature));
-  Method method;
-  method.type = METHOD_FN_CALL;
-  wrenBindMethod(vm, vm->fnClass, symbol, method);
-}
-
 void wrenInitializeCore(WrenVM* vm)
 {
   ObjModule* coreModule = wrenNewModule(vm, NULL);
@@ -1199,23 +1224,23 @@ void wrenInitializeCore(WrenVM* vm)
   PRIMITIVE(vm->fnClass->obj.classObj, "new(_)", fn_new);
 
   PRIMITIVE(vm->fnClass, "arity", fn_arity);
-  fnCall(vm, "call()");
-  fnCall(vm, "call(_)");
-  fnCall(vm, "call(_,_)");
-  fnCall(vm, "call(_,_,_)");
-  fnCall(vm, "call(_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_,_)");
-  fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_)");
+  PRIMITIVE(vm->fnClass, "call()", fn_call0);
+  PRIMITIVE(vm->fnClass, "call(_)", fn_call1);
+  PRIMITIVE(vm->fnClass, "call(_,_)", fn_call2);
+  PRIMITIVE(vm->fnClass, "call(_,_,_)", fn_call3);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_)", fn_call4);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_)", fn_call5);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_)", fn_call6);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_)", fn_call7);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_)", fn_call8);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_)", fn_call9);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_,_)", fn_call10);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_,_,_)", fn_call11);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_,_,_,_)", fn_call12);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_,_,_,_,_)", fn_call13);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_)", fn_call14);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_,_)", fn_call15);
+  PRIMITIVE(vm->fnClass, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_)", fn_call16);
   PRIMITIVE(vm->fnClass, "toString", fn_toString);
 
   vm->nullClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Null"));
diff --git a/src/vm/wren_primitive.h b/src/vm/wren_primitive.h
index f514f75f9..c2261c3b1 100644
--- a/src/vm/wren_primitive.h
+++ b/src/vm/wren_primitive.h
@@ -11,7 +11,7 @@
           &vm->methodNames, name, strlen(name)); \
       Method method; \
       method.type = METHOD_PRIMITIVE; \
-      method.fn.primitive = prim_##function; \
+      method.as.primitive = prim_##function; \
       wrenBindMethod(vm, cls, symbol, method); \
     }
 
diff --git a/src/vm/wren_value.c b/src/vm/wren_value.c
index fc645359d..1d5170454 100644
--- a/src/vm/wren_value.c
+++ b/src/vm/wren_value.c
@@ -1008,7 +1008,7 @@ static void blackenClass(WrenVM* vm, ObjClass* classObj)
   {
     if (classObj->methods.data[i].type == METHOD_BLOCK)
     {
-      wrenGrayObj(vm, (Obj*)classObj->methods.data[i].fn.obj);
+      wrenGrayObj(vm, (Obj*)classObj->methods.data[i].as.closure);
     }
   }
 
diff --git a/src/vm/wren_value.h b/src/vm/wren_value.h
index 31f19f503..38c496dc0 100644
--- a/src/vm/wren_value.h
+++ b/src/vm/wren_value.h
@@ -349,9 +349,6 @@ typedef enum
   // A normal user-defined method.
   METHOD_BLOCK,
   
-  // The special "call(...)" methods on function.
-  METHOD_FN_CALL,
-
   // No method for the given symbol.
   METHOD_NONE
 } MethodType;
@@ -366,10 +363,8 @@ typedef struct
   {
     Primitive primitive;
     WrenForeignMethodFn foreign;
-    
-    // May be a [ObjFn] or [ObjClosure].
-    ObjClosure* obj;
-  } fn;
+    ObjClosure* closure;
+  } as;
 } Method;
 
 DECLARE_BUFFER(Method, Method);
diff --git a/src/vm/wren_vm.c b/src/vm/wren_vm.c
index cdeb869fb..61b054271 100644
--- a/src/vm/wren_vm.c
+++ b/src/vm/wren_vm.c
@@ -342,12 +342,12 @@ static void bindMethod(WrenVM* vm, int methodType, int symbol,
   {
     const char* name = AS_CSTRING(methodValue);
     method.type = METHOD_FOREIGN;
-    method.fn.foreign = findForeignMethod(vm, module->name->value,
+    method.as.foreign = findForeignMethod(vm, module->name->value,
                                           className,
                                           methodType == CODE_METHOD_STATIC,
                                           name);
 
-    if (method.fn.foreign == NULL)
+    if (method.as.foreign == NULL)
     {
       vm->fiber->error = wrenStringFormat(vm,
           "Could not find foreign method '@' for class $ in module '$'.",
@@ -357,11 +357,11 @@ static void bindMethod(WrenVM* vm, int methodType, int symbol,
   }
   else
   {
-    method.fn.obj = AS_CLOSURE(methodValue);
+    method.as.closure = AS_CLOSURE(methodValue);
     method.type = METHOD_BLOCK;
 
     // Patch up the bytecode now that we know the superclass.
-    wrenBindMethodCode(classObj, method.fn.obj->fn);
+    wrenBindMethodCode(classObj, method.as.closure->fn);
   }
 
   wrenBindMethod(vm, classObj, symbol, method);
@@ -427,48 +427,6 @@ static void methodNotFound(WrenVM* vm, ObjClass* classObj, int symbol)
       OBJ_VAL(classObj->name), vm->methodNames.data[symbol]->value);
 }
 
-// Checks that [value], which must be a closure, does not require more
-// parameters than are provided by [numArgs].
-//
-// If there are not enough arguments, aborts the current fiber and returns
-// `false`.
-static bool checkArity(WrenVM* vm, Value value, int numArgs)
-{
-  ASSERT(IS_CLOSURE(value), "Receiver must be a closure.");
-  ObjFn* fn = AS_CLOSURE(value)->fn;
-
-  // We only care about missing arguments, not extras. The "- 1" is because
-  // numArgs includes the receiver, the function itself, which we don't want to
-  // count.
-  if (numArgs - 1 >= fn->arity) return true;
-
-  vm->fiber->error = CONST_STRING(vm, "Function expects more arguments.");
-  return false;
-}
-
-// Pushes [closure] onto [fiber]'s callstack and invokes it. Expects [numArgs]
-// arguments (including the receiver) to be on the top of the stack already.
-static inline void callFunction(
-    WrenVM* vm, ObjFiber* fiber, ObjClosure* closure, int numArgs)
-{
-  // Grow the call frame array if needed.
-  if (fiber->numFrames + 1 > fiber->frameCapacity)
-  {
-    int max = fiber->frameCapacity * 2;
-    fiber->frames = (CallFrame*)wrenReallocate(vm, fiber->frames,
-        sizeof(CallFrame) * fiber->frameCapacity,
-        sizeof(CallFrame) * max);
-    fiber->frameCapacity = max;
-  }
-  
-  // Grow the stack if needed.
-  int stackSize = (int)(fiber->stackTop - fiber->stack);
-  int needed = stackSize + closure->fn->maxSlots;
-  wrenEnsureStack(vm, fiber, needed);
-  
-  wrenAppendCallFrame(vm, fiber, closure, fiber->stackTop - numArgs);
-}
-
 // Looks up the previously loaded module with [name].
 //
 // Returns `NULL` if no module with that name has been loaded.
@@ -611,7 +569,7 @@ static void bindForeignClass(WrenVM* vm, ObjClass* classObj, ObjModule* module)
   int symbol = wrenSymbolTableEnsure(vm, &vm->methodNames, "<allocate>", 10);
   if (methods.allocate != NULL)
   {
-    method.fn.foreign = methods.allocate;
+    method.as.foreign = methods.allocate;
     wrenBindMethod(vm, classObj, symbol, method);
   }
   
@@ -620,7 +578,7 @@ static void bindForeignClass(WrenVM* vm, ObjClass* classObj, ObjModule* module)
   symbol = wrenSymbolTableEnsure(vm, &vm->methodNames, "<finalize>", 10);
   if (methods.finalize != NULL)
   {
-    method.fn.foreign = (WrenForeignMethodFn)methods.finalize;
+    method.as.foreign = (WrenForeignMethodFn)methods.finalize;
     wrenBindMethod(vm, classObj, symbol, method);
   }
 }
@@ -669,7 +627,7 @@ static void createForeign(WrenVM* vm, ObjFiber* fiber, Value* stack)
   Value* oldApiStack = vm->apiStack;
   vm->apiStack = stack;
 
-  method->fn.foreign(vm);
+  method->as.foreign(vm);
 
   vm->apiStack = oldApiStack;
   // TODO: Check that allocateForeign was called.
@@ -693,7 +651,7 @@ void wrenFinalizeForeign(WrenVM* vm, ObjForeign* foreign)
 
   ASSERT(method->type == METHOD_FOREIGN, "Finalizer should be foreign.");
 
-  WrenFinalizerFn finalizer = (WrenFinalizerFn)method->fn.foreign;
+  WrenFinalizerFn finalizer = (WrenFinalizerFn)method->as.foreign;
   finalizer(foreign->data);
 }
 
@@ -1033,13 +991,13 @@ static WrenInterpretResult runInterpreter(WrenVM* vm, register ObjFiber* fiber)
       switch (method->type)
       {
         case METHOD_PRIMITIVE:
-          if (method->fn.primitive(vm, args))
+          if (method->as.primitive(vm, args))
           {
             // The result is now in the first arg slot. Discard the other
             // stack slots.
             fiber->stackTop -= numArgs - 1;
           } else {
-            // An error or fiber switch occurred.
+            // An error, fiber switch, or call frame change occurred.
             STORE_FRAME();
 
             // If we don't have a fiber to switch to, stop interpreting.
@@ -1051,21 +1009,13 @@ static WrenInterpretResult runInterpreter(WrenVM* vm, register ObjFiber* fiber)
           break;
 
         case METHOD_FOREIGN:
-          callForeign(vm, fiber, method->fn.foreign, numArgs);
+          callForeign(vm, fiber, method->as.foreign, numArgs);
           if (!IS_NULL(fiber->error)) RUNTIME_ERROR();
           break;
 
-        case METHOD_FN_CALL:
-          if (!checkArity(vm, args[0], numArgs)) RUNTIME_ERROR();
-
-          STORE_FRAME();
-          callFunction(vm, fiber, AS_CLOSURE(args[0]), numArgs);
-          LOAD_FRAME();
-          break;
-
         case METHOD_BLOCK:
           STORE_FRAME();
-          callFunction(vm, fiber, (ObjClosure*)method->fn.obj, numArgs);
+          wrenCallFunction(vm, fiber, (ObjClosure*)method->as.closure, numArgs);
           LOAD_FRAME();
           break;
 
@@ -1327,7 +1277,7 @@ static WrenInterpretResult runInterpreter(WrenVM* vm, register ObjFiber* fiber)
       {
         STORE_FRAME();
         ObjClosure* closure = AS_CLOSURE(PEEK());
-        callFunction(vm, fiber, closure, 1);
+        wrenCallFunction(vm, fiber, closure, 1);
         LOAD_FRAME();
       }
       else
@@ -1433,7 +1383,7 @@ WrenInterpretResult wrenCall(WrenVM* vm, WrenHandle* method)
   // function has exactly one slot for each argument.
   vm->fiber->stackTop = &vm->fiber->stack[closure->fn->maxSlots];
   
-  callFunction(vm, vm->fiber, closure, 0);
+  wrenCallFunction(vm, vm->fiber, closure, 0);
   return runInterpreter(vm, vm->fiber);
 }
 
diff --git a/src/vm/wren_vm.h b/src/vm/wren_vm.h
index 3cfaeee77..b4b010f5f 100644
--- a/src/vm/wren_vm.h
+++ b/src/vm/wren_vm.h
@@ -174,10 +174,32 @@ int wrenDeclareVariable(WrenVM* vm, ObjModule* module, const char* name,
 int wrenDefineVariable(WrenVM* vm, ObjModule* module, const char* name,
                        size_t length, Value value);
 
-// Mark [obj] as a GC root so that it doesn't get collected.
+// Pushes [closure] onto [fiber]'s callstack to invoke it. Expects [numArgs]
+// arguments (including the receiver) to be on the top of the stack already.
+static inline void wrenCallFunction(WrenVM* vm, ObjFiber* fiber,
+                                    ObjClosure* closure, int numArgs)
+{
+  // Grow the call frame array if needed.
+  if (fiber->numFrames + 1 > fiber->frameCapacity)
+  {
+    int max = fiber->frameCapacity * 2;
+    fiber->frames = (CallFrame*)wrenReallocate(vm, fiber->frames,
+        sizeof(CallFrame) * fiber->frameCapacity, sizeof(CallFrame) * max);
+    fiber->frameCapacity = max;
+  }
+  
+  // Grow the stack if needed.
+  int stackSize = (int)(fiber->stackTop - fiber->stack);
+  int needed = stackSize + closure->fn->maxSlots;
+  wrenEnsureStack(vm, fiber, needed);
+  
+  wrenAppendCallFrame(vm, fiber, closure, fiber->stackTop - numArgs);
+}
+
+// Marks [obj] as a GC root so that it doesn't get collected.
 void wrenPushRoot(WrenVM* vm, Obj* obj);
 
-// Remove the most recently pushed temporary root.
+// Removes the most recently pushed temporary root.
 void wrenPopRoot(WrenVM* vm);
 
 // Returns the class of [value].