compiler: Tweak pairwise_or

Author: FabioLuporini

devito/ir/support/guards.py

@@ -291,6 +291,7 @@ def xandg(self, d, guard):
 
     def pairwise_or(self, d, *guards):
         m = dict(self)
+        guards = list(guards)
 
         if d in m:
             guards.append(m[d])
@@ -490,7 +491,9 @@ def pairwise_or(*guards):
 
     # Analysis
     for guard in guards:
-        if guard is true or guard is None:
+        if guard is true:
+            return true
+        elif guard is None:
             continue
         elif isinstance(guard, And):
             components = guard.args