compiler: make lower_expr apply the mapper to indices in case functio…

…n only appear as index

.github/workflows/tutorials.yml

@@ -90,7 +90,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -e .
-        pip install matplotlib blosc
+        pip install matplotlib blosc cycler==0.10
 
     - name: Seismic notebooks
       run: |

devito/ir/equations/algorithms.py

@@ -134,7 +134,7 @@ def lower_exprs(expressions, **kwargs):
             dimension_map = {}
 
         # Handle Functions (typical case)
-        mapper = {f: f.indexify(lshift=True, subs=dimension_map)
+        mapper = {f: lower_exprs(f.indexify(subs=dimension_map), **kwargs)
                   for f in retrieve_functions(expr)}
 
         # Handle Indexeds (from index notation)
@@ -160,6 +160,7 @@ def lower_exprs(expressions, **kwargs):
         mapper.update(dimension_map)
         # Add the user-supplied substitutions
         mapper.update(subs)
+        # Apply mapper to expression
         processed.append(uxreplace(expr, mapper))
 
     if isinstance(expressions, Iterable):

devito/types/basic.py

@@ -1069,7 +1069,7 @@ def _data_alignment(self):
         """
         return default_allocator().guaranteed_alignment
 
-    def indexify(self, indices=None, lshift=False, subs=None):
+    def indexify(self, indices=None, subs=None):
         """Create a types.Indexed from the current object."""
         if indices is not None:
             return Indexed(self.indexed, *indices)
@@ -1078,11 +1078,9 @@ def indexify(self, indices=None, lshift=False, subs=None):
         subs = subs or {}
         subs = [{**{d.spacing: 1, -d.spacing: -1}, **subs} for d in self.dimensions]
 
-        # Add halo shift
-        shift = self._size_nodomain.left if lshift else tuple([0]*len(self.dimensions))
         # Indices after substitutions
-        indices = [sympy.sympify((a - o + f).xreplace(s)) for a, o, f, s in
-                   zip(self.args, self.origin, shift, subs)]
+        indices = [sympy.sympify((a - o).xreplace(s)) for a, o, s in
+                   zip(self.args, self.origin, subs)]
         indices = [i.xreplace({k: sympy.Integer(k) for k in i.atoms(sympy.Float)})
                    for i in indices]
         return self.indexed[indices]