undo redundant Py->C->Py coercions that originate from "optimisations"

Cython/Compiler/Optimize.py

@@ -1968,6 +1968,36 @@ class OptimizeBuiltinCalls(Visitor.NodeRefCleanupMixin,
                 return arg.arg.coerce_to_boolean(self.current_env())
         return node
 
+    PyNumber_Float_func_type = PyrexTypes.CFuncType(
+        PyrexTypes.py_object_type, [
+            PyrexTypes.CFuncTypeArg("o", PyrexTypes.py_object_type, None)
+            ])
+
+    def visit_CoerceToPyTypeNode(self, node):
+        """Drop redundant conversion nodes after tree changes."""
+        self.visitchildren(node)
+        arg = node.arg
+        if isinstance(arg, ExprNodes.CoerceFromPyTypeNode):
+            arg = arg.arg
+        if arg.type.is_pyobject:
+            if node.type in (arg.type, PyrexTypes.py_object_type):
+                return arg
+        if isinstance(arg, ExprNodes.PythonCapiCallNode):
+            if arg.function.name == 'float' and len(arg.args) == 1:
+                # undo redundant Py->C->Py coercion
+                func_arg = arg.args[0]
+                if func_arg.type is Builtin.float_type:
+                    return func_arg.as_none_safe_node("float() argument must be a string or a number, not 'NoneType'")
+                elif func_arg.type.is_pyobject:
+                    return ExprNodes.PythonCapiCallNode(
+                        node.pos, '__Pyx_PyNumber_Float', self.PyNumber_Float_func_type,
+                        args=[func_arg],
+                        py_name='float',
+                        is_temp=node.is_temp,
+                        result_is_used=node.result_is_used,
+                    ).coerce_to(node.type, self.current_env())
+        return node
+
     def visit_CoerceFromPyTypeNode(self, node):
         """Drop redundant conversion nodes after tree changes.
 
@@ -2337,7 +2367,7 @@ class OptimizeBuiltinCalls(Visitor.NodeRefCleanupMixin,
                 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,
+                node.pos, "__Pyx_PyNumber_Int", self.PyNumber_Int_func_type,
                 args=pos_args, is_temp=True, py_name='int')
         return node
 

Cython/Utility/TypeConversion.c

@@ -81,7 +81,7 @@ static CYTHON_INLINE size_t __Pyx_Py_UNICODE_strlen(const Py_UNICODE *u)
 #define __Pyx_Owned_Py_None(b) __Pyx_NewRef(Py_None)
 #define __Pyx_PyBool_FromLong(b) ((b) ? __Pyx_NewRef(Py_True) : __Pyx_NewRef(Py_False))
 static CYTHON_INLINE int __Pyx_PyObject_IsTrue(PyObject*);
-static CYTHON_INLINE PyObject* __Pyx_PyNumber_Int(PyObject* x);
+static CYTHON_INLINE PyObject* __Pyx_PyNumber_IntOrLong(PyObject* x);
 
 static CYTHON_INLINE Py_ssize_t __Pyx_PyIndex_AsSsize_t(PyObject*);
 static CYTHON_INLINE PyObject * __Pyx_PyInt_FromSize_t(size_t);
@@ -93,6 +93,13 @@ static CYTHON_INLINE PyObject * __Pyx_PyInt_FromSize_t(size_t);
 #endif
 #define __pyx_PyFloat_AsFloat(x) ((float) __pyx_PyFloat_AsDouble(x))
 
+#if PY_MAJOR_VERSION >= 3
+#define __Pyx_PyNumber_Int(x) (PyLong_CheckExact(x) ? __Pyx_NewRef(x) : PyNumber_Long(x))
+#else
+#define __Pyx_PyNumber_Int(x) (PyInt_CheckExact(x) ? __Pyx_NewRef(x) : PyNumber_Int(x))
+#endif
+#define __Pyx_PyNumber_Float(x) (PyFloat_CheckExact(x) ? __Pyx_NewRef(x) : PyNumber_Float(x))
+
 #if PY_MAJOR_VERSION < 3 && __PYX_DEFAULT_STRING_ENCODING_IS_ASCII
 static int __Pyx_sys_getdefaultencoding_not_ascii;
 static int __Pyx_init_sys_getdefaultencoding_params(void) {
@@ -258,7 +265,7 @@ static CYTHON_INLINE int __Pyx_PyObject_IsTrue(PyObject* x) {
    else return PyObject_IsTrue(x);
 }
 
-static CYTHON_INLINE PyObject* __Pyx_PyNumber_Int(PyObject* x) {
+static CYTHON_INLINE PyObject* __Pyx_PyNumber_IntOrLong(PyObject* x) {
   PyNumberMethods *m;
   const char *name = NULL;
   PyObject *res = NULL;
@@ -707,7 +714,7 @@ static CYTHON_INLINE {{TYPE}} {{FROM_PY_FUNCTION}}(PyObject *x) {
                             "_PyLong_AsByteArray() not available in PyPy, cannot convert large numbers");
 #else
             {{TYPE}} val;
-            PyObject *v = __Pyx_PyNumber_Int(x);
+            PyObject *v = __Pyx_PyNumber_IntOrLong(x);
  #if PY_MAJOR_VERSION < 3
             if (likely(v) && !PyLong_Check(v)) {
                 PyObject *tmp = v;
@@ -730,7 +737,7 @@ static CYTHON_INLINE {{TYPE}} {{FROM_PY_FUNCTION}}(PyObject *x) {
         }
     } else {
         {{TYPE}} val;
-        PyObject *tmp = __Pyx_PyNumber_Int(x);
+        PyObject *tmp = __Pyx_PyNumber_IntOrLong(x);
         if (!tmp) return ({{TYPE}}) -1;
         val = {{FROM_PY_FUNCTION}}(tmp);
         Py_DECREF(tmp);