Simplify max/min calculations a bit

python/dune/perftool/loopy/target.py

@@ -70,7 +70,7 @@ class DuneCExpressionToCodeMapper(CExpressionToCodeMapper):
         """
         what = type(expr).__name__.lower()
 
-        children = list(expr.children)
+        children = list(set(expr.children))
 
         result = self.rec(children.pop(), PREC_NONE)
         while children: