Remove a tiny bit of time overhead in mockbuffer test support.

tests/buffers/mockbuffers.pxi

@@ -31,11 +31,12 @@ cdef class MockBuffer:
     def __init__(self, label, data, shape=None, strides=None, format=None, writable=True, offset=0):
         # It is important not to store references to data after the constructor
         # as refcounting is checked on object buffers.
+        cdef Py_ssize_t x, s, cumprod, itemsize
         self.label = label
         self.release_ok = True
         self.log = ""
         self.offset = offset
-        self.itemsize = self.get_itemsize()
+        self.itemsize = itemsize = self.get_itemsize()
         self.writable = writable
         if format is None: format = self.get_default_format()
         if shape is None: shape = (len(data),)
@@ -48,7 +49,7 @@ cdef class MockBuffer:
                 strides.append(cumprod)
                 cumprod *= s
             strides.reverse()
-        strides = [x * self.itemsize for x in strides]
+        strides = [x * itemsize for x in strides]
         suboffsets = [-1] * len(shape)
         datashape = [len(data)]
         p = data
@@ -61,8 +62,10 @@ cdef class MockBuffer:
             self.ndim = <int>len(datashape)
             shape = datashape
             self.buffer = self.create_indirect_buffer(data, shape)
-            suboffsets = [0] * (self.ndim-1) + [-1]
-            strides = [sizeof(void*)] * (self.ndim-1) + [self.itemsize]
+            suboffsets = [0] * self.ndim
+            suboffsets[-1] = -1
+            strides = [sizeof(void*)] * self.ndim
+            strides[-1] = itemsize
             self.suboffsets = self.list_to_sizebuf(suboffsets)
         else:
             # strided and/or simple access
@@ -75,7 +78,7 @@ cdef class MockBuffer:
         except AttributeError:
             pass
         self.format = format
-        self.len = len(data) * self.itemsize
+        self.len = len(data) * itemsize
 
         self.strides = self.list_to_sizebuf(strides)
         self.shape = self.list_to_sizebuf(shape)
@@ -119,6 +122,7 @@ cdef class MockBuffer:
             return buf
 
     cdef Py_ssize_t* list_to_sizebuf(self, l):
+        cdef Py_ssize_t i, x
         cdef size_t n = <size_t>len(l) * sizeof(Py_ssize_t)
         cdef Py_ssize_t* buf = <Py_ssize_t*>stdlib.malloc(n)
         for i, x in enumerate(l):