bc reg (SCase up (Loc l) alts) r
   | isConst alts = constCase reg (L l) alts r
   | otherwise = conCase True reg (L l) alts r
bc reg (SCase up (Loc l) alts) r
   | isConst alts = constCase reg (L l) alts r
   | otherwise = conCase True reg (L l) alts r
bc reg (SCase up (Loc l) alts) r
   | isConst alts = constCase reg (L l) alts r
   | otherwise = conCase True reg (L l) alts r