[(m,n) | m <- [1..max], n <- [1..max]]
Hence the check for NoCaseOfCase.
-Note [Case of cast]
-~~~~~~~~~~~~~~~~~~~
-Consider case (v `cast` co) of x { I# ->
- ... (case (v `cast` co) of {...}) ...
-We'd like to eliminate the inner case. We can get this neatly by
-arranging that inside the outer case we add the unfolding
- v |-> x `cast` (sym co)
-to v. Then we should inline v at the inner case, cancel the casts, and away we go
-
-Note 2
-~~~~~~
-There is another situation when we don't want to do it. If we have
+Note [Suppressing the case binder-swap]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+There is another situation when it might make sense to suppress the
+case-expression binde-swap. If we have
case x of w1 { DEFAULT -> case x of w2 { A -> e1; B -> e2 }
...other cases .... }
after the outer case, and that makes (a,b) alive. At least we do unless
the case binder is guaranteed dead.
+Note [Case of cast]
+~~~~~~~~~~~~~~~~~~~
+Consider case (v `cast` co) of x { I# ->
+ ... (case (v `cast` co) of {...}) ...
+We'd like to eliminate the inner case. We can get this neatly by
+arranging that inside the outer case we add the unfolding
+ v |-> x `cast` (sym co)
+to v. Then we should inline v at the inner case, cancel the casts, and away we go
+
\begin{code}
simplCaseBinder :: SimplEnv -> OutExpr -> InId -> SimplM (SimplEnv, OutId)
simplCaseBinder env scrut case_bndr