Commit ac4a2563 authored by twanvl's avatar twanvl
Browse files

Fixed warnings in simplCore/CSE

parent 9cc7aff0
......@@ -4,13 +4,6 @@
\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
......@@ -194,7 +187,7 @@ cseProgram dflags binds
}
cseBinds :: CSEnv -> [CoreBind] -> [CoreBind]
cseBinds env [] = []
cseBinds _ [] = []
cseBinds env (b:bs) = (b':bs')
where
(env1, b') = cseBind env b
......@@ -207,6 +200,7 @@ cseBind env (Rec pairs) = let (env', pairs') = mapAccumL do_one env pairs
in (env', Rec pairs')
do_one :: CSEnv -> (Id, CoreExpr) -> (CSEnv, (Id, CoreExpr))
do_one env (id, rhs)
= case lookupCSEnv env rhs' of
Just (Var other_id) -> (extendSubst env' id other_id, (id', Var other_id))
......@@ -219,7 +213,7 @@ do_one env (id, rhs)
-- See Note [CSE for INLINE and NOINLINE]
tryForCSE :: CSEnv -> CoreExpr -> CoreExpr
tryForCSE env (Type t) = Type t
tryForCSE _ (Type t) = Type t
tryForCSE env expr = case lookupCSEnv env expr' of
Just smaller_expr -> smaller_expr
Nothing -> expr'
......@@ -227,11 +221,11 @@ tryForCSE env expr = case lookupCSEnv env expr' of
expr' = cseExpr env expr
cseExpr :: CSEnv -> CoreExpr -> CoreExpr
cseExpr env (Type t) = Type t
cseExpr env (Lit lit) = Lit lit
cseExpr _ (Type t) = Type t
cseExpr _ (Lit lit) = Lit lit
cseExpr env (Var v) = Var (lookupSubst env v)
cseExpr env (App f a) = App (cseExpr env f) (tryForCSE env a)
cseExpr env (Note InlineMe e) = Note InlineMe e -- See Note [CSE for INLINE and NOINLINE]
cseExpr _ (Note InlineMe e) = Note InlineMe e -- See Note [CSE for INLINE and NOINLINE]
cseExpr env (Note n e) = Note n (cseExpr env e)
cseExpr env (Cast e co) = Cast (cseExpr env e) co
cseExpr env (Lam b e) = let (env', b') = addBinder env b
......@@ -244,7 +238,9 @@ cseExpr env (Case scrut bndr ty alts) = Case scrut' bndr' ty (cseAlts env' scrut
(env', bndr') = addBinder env bndr
cseAlts env scrut' bndr bndr' [(DataAlt con, args, rhs)]
cseAlts :: CSEnv -> CoreExpr -> CoreBndr -> CoreBndr -> [CoreAlt] -> [CoreAlt]
cseAlts env scrut' bndr _bndr' [(DataAlt con, args, rhs)]
| isUnboxedTupleCon con
-- Unboxed tuples are special because the case binder isn't
-- a real values. See [Note: unboxed tuple case binders]
......@@ -263,7 +259,7 @@ cseAlts env scrut' bndr bndr' alts
Var v' -> (v', extendSubst env bndr v') -- See [Note: case binder 1]
-- map: bndr -> v'
other -> (bndr', extendCSEnv env scrut' (Var bndr')) -- See [Note: case binder 2]
_ -> (bndr', extendCSEnv env scrut' (Var bndr')) -- See [Note: case binder 2]
-- map: scrut' -> bndr'
arg_tys = tyConAppArgs (idType bndr)
......@@ -303,6 +299,7 @@ type CSEMap = UniqFM [(CoreExpr, CoreExpr)] -- This is the reverse mapping
-- This means that it's good to replace e by e'
-- INVARIANT: The expr in the range has already been CSE'd
emptyCSEnv :: CSEnv
emptyCSEnv = CS emptyUFM emptyInScopeSet emptyVarEnv
lookupCSEnv :: CSEnv -> CoreExpr -> Maybe CoreExpr
......@@ -312,15 +309,17 @@ lookupCSEnv (CS cs _ _) expr
Just pairs -> lookup_list pairs expr
lookup_list :: [(CoreExpr,CoreExpr)] -> CoreExpr -> Maybe CoreExpr
lookup_list [] expr = Nothing
lookup_list [] _ = Nothing
lookup_list ((e,e'):es) expr | cheapEqExpr e expr = Just e'
| otherwise = lookup_list es expr
addCSEnvItem :: CSEnv -> CoreExpr -> CoreExpr -> CSEnv
addCSEnvItem env expr expr' | exprIsBig expr = env
| otherwise = extendCSEnv env expr expr'
-- We don't try to CSE big expressions, because they are expensive to compare
-- (and are unlikely to be the same anyway)
extendCSEnv :: CSEnv -> CoreExpr -> CoreExpr -> CSEnv
extendCSEnv (CS cs in_scope sub) expr expr'
= CS (addToUFM_C combine cs hash [(expr, expr')]) in_scope sub
where
......@@ -333,14 +332,16 @@ extendCSEnv (CS cs in_scope sub) expr expr'
long_msg | opt_PprStyle_Debug = (text "hash code" <+> text (show hash)) $$ ppr result
| otherwise = empty
lookupSubst :: CSEnv -> Id -> Id
lookupSubst (CS _ _ sub) x = case lookupVarEnv sub x of
Just y -> y
Nothing -> x
extendSubst :: CSEnv -> Id -> Id -> CSEnv
extendSubst (CS cs in_scope sub) x y = CS cs in_scope (extendVarEnv sub x y)
addBinder :: CSEnv -> Id -> (CSEnv, Id)
addBinder env@(CS cs in_scope sub) v
addBinder (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')
| otherwise = WARN( True, ppr v )
......
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