tests: Fix TestDependenceAnalysis

Author: enwask

tests/test_ir.py

@@ -17,6 +17,7 @@
 from devito.ir.support.guards import GuardOverflow
 from devito.symbolics import DefFunction, FieldFromPointer
 from devito.tools import prod
+from devito.tools.data_structures import frozendict
 from devito.types import Array, Bundle, CriticalRegion, Jump, Scalar, Symbol
 
 
@@ -611,9 +612,9 @@ def test_single_eq(self, expr, expected, ti0, ti1, fa, grid):
         """
         expr = LoweredEq(EVAL(expr, ti0.base, ti1.base, fa))
 
-        # Force innatural flow, only to stress the compiler to see if it was
+        # Force unnatural flow, only to stress the compiler to see if it is
         # capable of detecting anti-dependences
-        expr.ispace._directions = {i: Forward for i in expr.ispace.directions}
+        expr.ispace._directions = frozendict({i: Forward for i in expr.ispace.directions})
 
         scope = Scope(expr)
         deps = scope.d_all
@@ -709,10 +710,10 @@ def test_multiple_eqs(self, exprs, expected, ti0, ti1, ti3, fa):
         exprs = [LoweredEq(i) for i in EVAL(exprs, ti0.base, ti1.base, ti3.base, fa)]
         expected = [tuple(i.split(',')) for i in expected]
 
-        # Force innatural flow, only to stress the compiler to see if it was
+        # Force unnatural flow, only to stress the compiler to see if it is
         # capable of detecting anti-dependences
         for i in exprs:
-            i.ispace._directions = {i: Forward for i in i.ispace.directions}
+            i.ispace._directions = frozendict({i: Forward for i in i.ispace.directions})
 
         scope = Scope(exprs)
         assert len(scope.d_all) == len(expected)