\section{Common subexpression}
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module CSE (
cseProgram
) where
import Outputable
import StaticFlags ( opt_PprStyle_Debug )
import BasicTypes ( isAlwaysActive )
-import Util ( mapAccumL, lengthExceeds )
+import Util ( lengthExceeds )
import UniqFM
+
+import Data.List
\end{code}
addBinder env@(CS cs in_scope sub) v
| not (v `elemInScopeSet` in_scope) = (CS cs (extendInScopeSet in_scope v) sub, v)
| isId v = (CS cs (extendInScopeSet in_scope v') (extendVarEnv sub v v'), v')
- | not (isId v) = WARN( True, ppr v )
+ | otherwise = WARN( True, ppr v )
(CS emptyUFM in_scope sub, v)
-- This last case is the unusual situation where we have shadowing of
-- a type variable; we have to discard the CSE mapping