speed up non-kwargs Python function/method calls by up to 20% by avoiding tuple creation

Cython/Compiler/ExprNodes.py

@@ -5574,6 +5574,29 @@ class PyMethodCallNode(SimpleCallNode):
             else:
                 arg_offset = arg_offset_cname
 
+            code.putln("#if CYTHON_FAST_PYCALL")
+            code.putln("if (PyFunction_Check(%s)) {" % function)
+            code.putln("PyObject *%s[%d] = {%s, %s};" % (
+                Naming.quick_temp_cname,
+                len(args)+1,
+                self_arg,
+                ', '.join(arg.py_result() for arg in args)))
+            code.putln("%s = __Pyx_PyFunction_FastCall(%s, %s+1-%s, %d+%s, NULL); %s" % (
+                self.result(),
+                function,
+                Naming.quick_temp_cname,
+                arg_offset,
+                len(args),
+                arg_offset,
+                code.error_goto_if_null(self.result(), self.pos)))
+            code.put_xdecref_clear(self_arg, py_object_type)
+            code.put_gotref(self.py_result())
+            for arg in args:
+                arg.generate_disposal_code(code)
+            code.putln("} else")
+            code.putln("#endif")
+
+            code.putln("{")
             args_tuple = code.funcstate.allocate_temp(py_object_type, manage_ref=True)
             code.putln("%s = PyTuple_New(%d+%s); %s" % (
                 args_tuple, len(args), arg_offset,
@@ -5614,6 +5637,7 @@ class PyMethodCallNode(SimpleCallNode):
 
             if len(args) == 1:
                 code.putln("}")
+            code.putln("}")  # !CYTHON_FAST_PYCALL
 
         if reuse_function_temp:
             self.function.generate_disposal_code(code)