Big tidy-up of deriving code

[ghc-hetmet.git] / compiler / simplCore / SimplUtils.lhs

diff --git a/compiler/simplCore/SimplUtils.lhs b/compiler/simplCore/SimplUtils.lhs
index fbe5f18..cd507b5 100644 (file)
--- a/compiler/simplCore/SimplUtils.lhs
+++ b/compiler/simplCore/SimplUtils.lhs
@@ -216,6 +216,14 @@ interestingArg (Var v)              = hasSomeUnfolding (idUnfolding v)
 interestingArg (Type _)                 = False
 interestingArg (App fn (Type _)) = interestingArg fn
 interestingArg (Note _ a)       = interestingArg a
+
+-- Idea (from Sam B); I'm not sure if it's a good idea, so commented out for now
+-- interestingArg expr | isUnLiftedType (exprType expr)
+--        -- Unlifted args are only ever interesting if we know what they are
+--  =                  case expr of
+--                        Lit lit -> True
+--                        _       -> False
+
 interestingArg other            = True
        -- Consider     let x = 3 in f x
        -- The substitution will contain (x -> ContEx 3), and we want to
@@ -777,7 +785,7 @@ activeRule env
                        -- to work in Template Haskell when simplifying
                        -- splices, so we get simpler code for literal strings
        SimplPhase n -> Just (isActive n)
-\end{code}     
+\end{code}
 
 
 %************************************************************************
@@ -1251,7 +1259,7 @@ match.  For example:
          other -> ...(case x of
                         0#    -> ...
                         other -> ...) ...
-\end{code}
+\end{verbatim}
 Here the inner case can be eliminated.  This really only shows up in
 eliminating error-checking code.