compiler: Drop unused shift_back

devito/ir/support/utils.py

@@ -1,13 +1,12 @@
 from collections import defaultdict
 
-from devito.symbolics import (CallFromPointer, retrieve_indexed, retrieve_terminals,
-                              uxreplace)
+from devito.symbolics import CallFromPointer, retrieve_indexed, retrieve_terminals
 from devito.tools import DefaultOrderedDict, as_tuple, flatten, filter_sorted, split
 from devito.types import (Dimension, DimensionTuple, Indirection, ModuloDimension,
                           StencilDimension)
 
 __all__ = ['AccessMode', 'Stencil', 'IMask', 'detect_accesses', 'detect_io',
-           'pull_dims', 'shift_back', 'sdims_min', 'sdims_max']
+           'pull_dims', 'sdims_min', 'sdims_max']
 
 
 class AccessMode(object):
@@ -270,26 +269,6 @@ def pull_dims(exprs, flag=True):
         return dims
 
 
-def shift_back(objects):
-    """
-    Translate the Indexeds in a given collection of objects along all
-    Dimensions by the left-halo.
-
-    This is useful to create input for recursive compilation from pre-existing,
-    and therefore already lowered/indefixied, input.
-    """
-    processed = []
-    for o in as_tuple(objects):
-        subs = {}
-        for i in retrieve_indexed(o):
-            subs[i] = i.subs({v: v - s.left
-                              for v, s in zip(i.indices, i.function._size_halo)})
-
-        processed.append(uxreplace(o, subs))
-
-    return processed
-
-
 # *** Utility functions for expressions that potentially contain StencilDimensions
 
 def sdims_min(expr):