compiler: fix multi-cond async

Author: mloubout

devito/finite_differences/finite_difference.py

@@ -157,6 +157,8 @@ def first_derivative(expr, dim, fd_order, **kwargs):
 
 def make_derivative(expr, dim, fd_order, deriv_order, side, matvec, x0, coefficients,
                     expand, weights=None):
+    if deriv_order == 0 and not expr.is_Add:
+        print(expr, dim, fd_order)
     # Always expand time derivatives to avoid issue with buffering and streaming.
     # Time derivative are almost always short stencils and won't benefit from
     # unexpansion in the rare case the derivative is not evaluated for time stepping.

devito/ir/equations/equation.py

@@ -229,7 +229,13 @@ def __new__(cls, *args, **kwargs):
             index = d.index
             if d.condition is not None and d in expr.free_symbols:
                 index = index - relational_min(d.condition, d.parent)
-            expr = uxreplace(expr, {d: IntDiv(index, d.symbolic_factor)})
+                # If there is a condition we might access on a non-factor
+                # index and need to make sure we don't overwrite the previous
+                # index
+                num = index + d.symbolic_factor - 1
+            else:
+                num = index
+            expr = uxreplace(expr, {d: IntDiv(num, d.symbolic_factor)})
 
         conditionals = frozendict(conditionals)
 

devito/passes/clusters/asynchrony.py

@@ -240,7 +240,7 @@ def _actions_from_update_memcpy(c, d, clusters, actions, sregistry):
 
     fetch = e.rhs.indices[d]
     fshift = {Forward: 1, Backward: -1}.get(direction, 0)
-    findex = fetch + fshift if fetch.find(IntDiv) else fetch._subs(pd, pd + fshift)
+    findex = fetch._subs(pd, pd + fshift)
 
     # If fetching into e.g. `ub[t1]` we might need to prefetch into e.g. `ub[t0]`
     tindex0 = e.lhs.indices[d]