Make IncSubtensor use the new NumPy API.

theano/tensor/subtensor.py

@@ -534,13 +534,12 @@ class Subtensor(Op):
         return {
             "c_prefix": "PyArray",
             "strides_mul": 1,
-            "view_name": "xview"}
+            }
 
     @staticmethod
     def helper_c_code(node, name, inputs, outputs, sub, idx_list, view_ndim,
                       c_prefix=None,
                       strides_mul=None,
-                      view_name=None
                   ):
         """
         The parameters c_prefix are there to allow reusing this
@@ -557,9 +556,6 @@ class Subtensor(Op):
         if c_prefix is None:
             c_prefix = default_args['c_prefix']
 
-        if view_name is None:
-            view_name = default_args['view_name']
-
         #
         # two arrays are created in C code:
         # is_slice: len == ndim, 0 means int, 1 means slice
@@ -633,8 +629,6 @@ class Subtensor(Op):
         x, = inputs[:1]
         z, = outputs
 
-        xview = view_name
-        
         rval = """
 
         // The subtensor is created by iterating over the dimensions
@@ -648,7 +642,7 @@ class Subtensor(Op):
         int outer_ii = 0; // current dimension of z
 
         // Argument of the view
-        char* xview_ptr = (char*) %(c_prefix)s_BYTES(%(x)s);
+        ssize_t xview_offset = 0;
         ssize_t xview_dims[%(view_ndim)s];
         ssize_t xview_strides[%(view_ndim)s];
 
@@ -720,7 +714,7 @@ class Subtensor(Op):
 
                 assert (slicelength <= length);
 
-                xview_ptr += %(c_prefix)s_STRIDES(%(x)s)[outer_ii] * start *
+                xview_offset += %(c_prefix)s_STRIDES(%(x)s)[outer_ii] * start *
                        %(strides_mul)s;
                 xview_dims[inner_ii] = slicelength;
                 xview_strides[inner_ii] = %(c_prefix)s_STRIDES(%(x)s)[outer_ii] * step;
@@ -736,7 +730,7 @@ class Subtensor(Op):
                 {
                     if (idx < %(c_prefix)s_DIMS(%(x)s)[outer_ii])
                     {
-                        xview_ptr += %(c_prefix)s_STRIDES(%(x)s)[outer_ii] * idx *
+                        xview_offset += %(c_prefix)s_STRIDES(%(x)s)[outer_ii] * idx *
                                %(strides_mul)s;
                     }
                     else
@@ -795,9 +789,9 @@ class Subtensor(Op):
                 &PyArray_Type,
                 PyArray_DESCR(%(x)s),
                 %(view_ndim)s,
-                xview_dims, //PyArray_DIMS(%(x)s),
-                xview_strides, //PyArray_STRIDES(%(x)s),
-                xview_ptr, //PyArray_DATA(%(x)s),
+                xview_dims,
+                xview_strides,
+                PyArray_BYTES(%(x)s) + xview_offset,
                 PyArray_FLAGS(%(x)s),
                 NULL);
         assert (PyArray_NDIM(xview) == %(view_ndim)s);
@@ -808,8 +802,7 @@ class Subtensor(Op):
         """ % locals()
 
         finish_view = """
-        //Is this update needed? The doc of PyArray_NewFromDescr do not
-        //tell us the information needed
+        //This is needed for NumPy 1.5, but not 1.7.2
         PyArray_UpdateFlags(xview, NPY_ARRAY_C_CONTIGUOUS| NPY_ARRAY_F_CONTIGUOUS);
         Py_XDECREF(%(z)s);
         Py_INCREF(py_%(x)s);
@@ -1178,6 +1171,7 @@ class IncSubtensor(Op):
                      numpy.sum([not isinstance(idx, slice)
                                 for idx in self.idx_list]))
 
+        decl = "PyArrayObject * zview = NULL;"
         copy_of_x = self.copy_of_x(x)
 
         copy_input_if_necessary = """
@@ -1201,7 +1195,21 @@ class IncSubtensor(Op):
         # On GPU, it takes two steps to make a view
         link_zview = self.link_view_array(z, fail)
 
-        #Make a first view on the output, as we will write into it.
+        # get info needed to make zview: a view of %(z)s
+        helper_args = self.get_helper_c_code_args()
+
+        get_zview = Subtensor.helper_c_code(
+            node=node,
+            name=name,
+            inputs=outputs[:1] + inputs[2:],
+            outputs=outputs,
+            sub=sub,
+            idx_list=self.idx_list,
+            view_ndim=view_ndim,
+            ** helper_args
+        )
+
+        #Make a view on the output, as we will write into it.
         build_view = """
         //TODO: give this Op a second output so that this view can be cached
         //TODO: alternatively, fix the memory leak on failure
@@ -1212,19 +1220,6 @@ class IncSubtensor(Op):
         }
         %(link_zview)s;
         """ % locals()
-        # make zview actually a view of %(z)s
-        helper_args = self.get_helper_c_code_args()
-        helper_args['view_name'] = 'zview'
-        get_zview = self.define_set_data() + \
-                Subtensor.helper_c_code(
-                node=node,
-                name=name,
-                inputs=outputs[:1] + inputs[2:],
-                outputs=outputs,
-                sub=sub,
-                idx_list=self.idx_list,
-                ** helper_args
-                )
 
         copy_into = self.copy_into("zview", y)
 
@@ -1245,11 +1240,12 @@ class IncSubtensor(Op):
         }
         """ % locals()
 
-        return (copy_input_if_necessary
-                + build_view
-                + "{" + get_zview + "}"
-                + make_modification
-                + "Py_DECREF(zview);"
+        return (decl +
+                copy_input_if_necessary +
+                get_zview +
+                build_view +
+                make_modification +
+                "Py_DECREF(zview);"
                 )
 
     def do_type_checking(self, node):
@@ -1299,16 +1295,18 @@ class IncSubtensor(Op):
         """
 
         return """Py_INCREF(PyArray_DESCR(%(x)s));
-        PyArrayObject * zview =
-                (PyArrayObject*)PyArray_NewFromDescr(
+        zview = (PyArrayObject*)PyArray_NewFromDescr(
                 &PyArray_Type,
                 PyArray_DESCR(%(x)s),
                 %(view_ndim)s,
-                PyArray_DIMS(%(x)s),
-                PyArray_STRIDES(%(x)s),
-                PyArray_DATA(%(x)s),
-                %(x)s->flags,
-                NULL)""" % locals()
+                xview_dims, //PyArray_DIMS(%(x)s),
+                xview_strides, //PyArray_STRIDES(%(x)s),
+                PyArray_BYTES(%(x)s) + xview_offset, //PyArray_DATA(%(x)s),
+                PyArray_FLAGS(%(x)s),
+                NULL);
+        //This is needed for NumPy 1.5, but not 1.7.2
+        PyArray_UpdateFlags(zview, NPY_ARRAY_C_CONTIGUOUS| NPY_ARRAY_F_CONTIGUOUS);
+        """ % locals()
 
     def get_helper_c_code_args(self):
         """ Return a dictionary of arguments to pass to helper_c_code."""
@@ -1324,11 +1322,6 @@ class IncSubtensor(Op):
         """
         return """PyArray_CopyInto(%(view)s, %(source)s)""" % locals()
 
-    def define_set_data(self):
-        """ Returns C code used to define any macros used in the
-        set data argument to the helper C code. """
-        return ""
-
     def link_view_array(self, x, fail):
         """ Returns code to complete making zview a view of x"""