call PyNumber_Int() for builtin int() function

Cython/Compiler/Optimize.py

@@ -1990,6 +1990,28 @@ class OptimizeBuiltinCalls(Visitor.MethodDispatcherTransform):
             utility_code = load_c_utility('pyobject_as_double'),
             py_name = "float")
 
+    PyNumber_Int_func_type = PyrexTypes.CFuncType(
+        PyrexTypes.py_object_type, [
+            PyrexTypes.CFuncTypeArg("o", PyrexTypes.py_object_type, None)
+            ])
+
+    def _handle_simple_function_int(self, node, function, pos_args):
+        """Transform int() into a faster C function call.
+        """
+        if len(pos_args) == 0:
+            return ExprNodes.IntNode(node, value="0", constant_result=0,
+                                     type=PyrexTypes.c_int_type)
+        elif len(pos_args) != 1:
+            return node  # int(x, base)
+        func_arg = pos_args[0]
+        if isinstance(func_arg, ExprNodes.CoerceToPyTypeNode):
+            return node  # handled in visit_CoerceFromPyTypeNode()
+        if func_arg.type.is_pyobject and node.type.is_pyobject:
+            return ExprNodes.PythonCapiCallNode(
+                node.pos, "PyNumber_Int", self.PyNumber_Int_func_type,
+                args=pos_args, is_temp=True)
+        return node
+
     def _handle_simple_function_bool(self, node, function, pos_args):
         """Transform bool(x) into a type coercion to a boolean.
         """

Cython/Utility/ModuleSetupCode.c

@@ -218,6 +218,7 @@
   #define PyInt_AsSsize_t              PyLong_AsSsize_t
   #define PyInt_AsUnsignedLongMask     PyLong_AsUnsignedLongMask
   #define PyInt_AsUnsignedLongLongMask PyLong_AsUnsignedLongLongMask
+  #define PyNumber_Int                 PyNumber_Long
 #endif
 
 #if PY_MAJOR_VERSION >= 3

tests/run/int_float_builtins_as_casts_T400.pyx

@@ -137,3 +137,47 @@ def double_to_double_int(double x):
     """
     cdef double r = int(x)
     return r
+
+@cython.test_fail_if_path_exists("//SimpleCallNode")
+@cython.test_assert_path_exists("//PythonCapiCallNode")
+def object_float(x):
+    """
+    >>> 4.05 < object_float(4.1) < 4.15
+    True
+    >>> object_float(2**100) == float(2**100)
+    True
+    >>> object_float(2.5**100) == float(2.5**100)
+    True
+    >>> object_float(4)
+    4.0
+    >>> object_float('4')
+    4.0
+    >>> object_float('4.0')
+    4.0
+    >>> object_float('4'.encode('ascii'))
+    4.0
+    >>> object_float('4.0'.encode('ascii'))
+    4.0
+    """
+    return float(x)
+
+@cython.test_fail_if_path_exists("//SimpleCallNode")
+@cython.test_assert_path_exists("//PythonCapiCallNode")
+def object_int(x):
+    """
+    >>> object_int(4)
+    4
+    >>> object_int(2**100) == 2**100 or object_int(2**100)
+    True
+    >>> object_int(-(2**100)) == -(2**100) or object_int(-(2**100))
+    True
+    >>> object_int(4.1)
+    4
+    >>> object_int(4.0)
+    4
+    >>> object_int('4')
+    4
+    >>> object_int('4'.encode('ascii'))
+    4
+    """
+    return int(x)