Continue rolling back pep-3141 changes that changed behavior from 2.5. This
round included:
 * Revert round to its 2.6 behavior (half away from 0).
 * Because round, floor, and ceil always return float again, it's no
   longer necessary to have them delegate to __xxx___, so I've ripped
   that out of their implementations and the Real ABC. This also helps
   in implementing types that work in both 2.6 and 3.0: you return int
   from the __xxx__ methods, and let it get enabled by the version
   upgrade.
 * Make pow(-1, .5) raise a ValueError again.
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 44a9d93..5e52e78 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -107,28 +107,9 @@
 FUNC2(atan2, atan2,
       "atan2(y, x)\n\nReturn the arc tangent (measured in radians) of y/x.\n"
       "Unlike atan(y/x), the signs of both x and y are considered.")
-
-static PyObject * math_ceil(PyObject *self, PyObject *number) {
-	static PyObject *ceil_str = NULL;
-	PyObject *method;
-
-	if (ceil_str == NULL) {
-		ceil_str = PyString_FromString("__ceil__");
-		if (ceil_str == NULL)
-			return NULL;
-	}
-
-	method = _PyType_Lookup(Py_Type(number), ceil_str);
-	if (method == NULL)
-		return math_1(number, ceil);
-	else
-		return PyObject_CallFunction(method, "O", number);
-}
-
-PyDoc_STRVAR(math_ceil_doc,
-	     "ceil(x)\n\nReturn the ceiling of x as a float.\n"
-	     "This is the smallest integral value >= x.");
-
+FUNC1(ceil, ceil,
+      "ceil(x)\n\nReturn the ceiling of x as a float.\n"
+      "This is the smallest integral value >= x.")
 FUNC1(cos, cos,
       "cos(x)\n\nReturn the cosine of x (measured in radians).")
 FUNC1(cosh, cosh,
@@ -147,28 +128,9 @@
       "exp(x)\n\nReturn e raised to the power of x.")
 FUNC1(fabs, fabs,
       "fabs(x)\n\nReturn the absolute value of the float x.")
-
-static PyObject * math_floor(PyObject *self, PyObject *number) {
-	static PyObject *floor_str = NULL;
-	PyObject *method;
-
-	if (floor_str == NULL) {
-		floor_str = PyString_FromString("__floor__");
-		if (floor_str == NULL)
-			return NULL;
-	}
-
-	method = _PyType_Lookup(Py_Type(number), floor_str);
-	if (method == NULL)
-		return math_1(number, floor);
-	else
-		return PyObject_CallFunction(method, "O", number);
-}
-
-PyDoc_STRVAR(math_floor_doc,
-	     "floor(x)\n\nReturn the floor of x as a float.\n"
-	     "This is the largest integral value <= x.");
-
+FUNC1(floor, floor,
+      "floor(x)\n\nReturn the floor of x as a float.\n"
+      "This is the largest integral value <= x.")
 FUNC2(fmod, fmod,
       "fmod(x,y)\n\nReturn fmod(x, y), according to platform C."
       "  x % y may differ.")