diff options
| -rw-r--r-- | compiler/GHC/Core/Opt/DmdAnal.hs | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/compiler/GHC/Core/Opt/DmdAnal.hs b/compiler/GHC/Core/Opt/DmdAnal.hs index bf1870c3ea..e59c8cc5a8 100644 --- a/compiler/GHC/Core/Opt/DmdAnal.hs +++ b/compiler/GHC/Core/Opt/DmdAnal.hs @@ -1890,18 +1890,26 @@ dmdFix top_lvl env let_dmd orig_pairs final_anal_env = extendAnalEnvs top_lvl env (map fst pairs') step :: Bool -> [(Id, CoreExpr)] -> (DmdEnv, [(Id, CoreExpr)]) - step first_round pairs = (lazy_fv, pairs') + step first_round pairs = (lazy_fv, pairs'') where -- In all but the first iteration, delete the virgin flag start_env | first_round = env | otherwise = nonVirgin env + bot_to_exn_div p@(id,rhs) | DmdSig ty <- idDmdSig id + , dt_div ty == botDiv + = (id `setIdDmdSig` DmdSig ty{dt_div=exnDiv},rhs) + | otherwise + = p + start = (extendAnalEnvs top_lvl start_env (map fst pairs), emptyVarEnv) !((_,!lazy_fv), !pairs') = mapAccumL my_downRhs start pairs -- mapAccumL: Use the new signature to do the next pair -- The occurrence analyser has arranged them in a good order -- so this can significantly reduce the number of iterations needed + !pairs'' | first_round = map bot_to_exn_div pairs' -- Note TODO + | otherwise = pairs' my_downRhs (env, lazy_fv) (id,rhs) = -- pprTrace "my_downRhs" (ppr id $$ ppr (idDmdSig id) $$ ppr sig) $ |