[pythran] properly handle power operator in pythran expression

Cython/Compiler/ExprNodes.py

@@ -11115,12 +11115,19 @@ class BinopNode(ExprNode):
         if self.type.is_pythran_expr:
             code.putln("// Pythran binop")
             code.putln("__Pyx_call_destructor(%s);" % self.result())
-            code.putln("new (&%s) decltype(%s){%s %s %s};" % (
-                self.result(),
-                self.result(),
-                self.operand1.pythran_result(),
-                self.operator,
-                self.operand2.pythran_result()))
+            if self.operator == '**':
+                code.putln("new (&%s) decltype(%s){pythonic::numpy::functor::power{}(%s, %s)};" % (
+                    self.result(),
+                    self.result(),
+                    self.operand1.pythran_result(),
+                    self.operand2.pythran_result()))
+            else:
+                code.putln("new (&%s) decltype(%s){%s %s %s};" % (
+                    self.result(),
+                    self.result(),
+                    self.operand1.pythran_result(),
+                    self.operator,
+                    self.operand2.pythran_result()))
         elif self.operand1.type.is_pyobject:
             function = self.py_operation_function(code)
             if self.operator == '**':

Cython/Compiler/Pythran.py

@@ -60,8 +60,12 @@ def type_remove_ref(ty):
 
 
 def pythran_binop_type(op, tA, tB):
-    return "decltype(std::declval<%s>() %s std::declval<%s>())" % (
-        pythran_type(tA), op, pythran_type(tB))
+    if op == '**':
+        return 'decltype(pythonic::numpy::functor::power{}(std::declval<%s>(), std::declval<%s>()))' % (
+            pythran_type(tA), pythran_type(tB))
+    else:
+        return "decltype(std::declval<%s>() %s std::declval<%s>())" % (
+            pythran_type(tA), op, pythran_type(tB))
 
 
 def pythran_unaryop_type(op, type_):
@@ -209,6 +213,7 @@ def include_pythran_generic(env):
     env.add_include_file("pythonic/python/core.hpp")
     env.add_include_file("pythonic/types/bool.hpp")
     env.add_include_file("pythonic/types/ndarray.hpp")
+    env.add_include_file("pythonic/numpy/power.hpp")
     env.add_include_file("<new>")  # for placement new
 
     for i in (8, 16, 32, 64):

tests/run/numpy_pythran_unit.pyx

@@ -13,3 +13,13 @@ def trigo(np.ndarray[double, ndim=1] angles):
     array([ 1., -1.,  1.])
     """
     return np.cos(angles)
+
+def power(np.ndarray[double, ndim=1] values):
+
+    """
+    >>> a = np.array([0., 1., 2.])
+    >>> res = power(a)
+    >>> res[0], res[1], res[2]
+    (0.0, 1.0, 8.0)
+    """
+    return values ** 3