diff options
| author | Bartosz Nitka <niteria@gmail.com> | 2016-05-17 02:46:30 -0700 |
|---|---|---|
| committer | Bartosz Nitka <niteria@gmail.com> | 2016-05-17 03:40:58 -0700 |
| commit | dc94914eb0da985a2f006e2bd390fa1fdbafcc33 (patch) | |
| tree | a12af48f66de26433c2446bbffa7088f3a1fe3a6 | |
| parent | 770d7085d6e3f3e74e3ffe318aeaf135cf3aea72 (diff) | |
| download | haskell-dc94914eb0da985a2f006e2bd390fa1fdbafcc33.tar.gz | |
Document determinism in shortOutIndirections
varEnvElts didn't introduce nondeterminism here. This makes it
obvious that it could and explains why it doesn't.
Test Plan: ./validate
Reviewers: bgamari, simonmar, austin, simonpj
Reviewed By: simonpj
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D2228
GHC Trac Issues: #4012
| -rw-r--r-- | compiler/simplCore/SimplCore.hs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/compiler/simplCore/SimplCore.hs b/compiler/simplCore/SimplCore.hs index 86eadc7a37..6884696c97 100644 --- a/compiler/simplCore/SimplCore.hs +++ b/compiler/simplCore/SimplCore.hs @@ -51,6 +51,7 @@ import Module import Maybes import UniqSupply ( UniqSupply, mkSplitUniqSupply, splitUniqSupply ) +import UniqFM import Outputable import Control.Monad import qualified GHC.LanguageExtensions as LangExt @@ -901,7 +902,10 @@ shortOutIndirections binds where ind_env = makeIndEnv binds -- These exported Ids are the subjects of the indirection-elimination - exp_ids = map fst $ varEnvElts ind_env + exp_ids = map fst $ nonDetEltsUFM ind_env + -- It's OK to use nonDetEltsUFM here because we forget the ordering + -- by immediately converting to a set or check if all the elements + -- satisfy a predicate. exp_id_set = mkVarSet exp_ids no_need_to_flatten = all (null . ruleInfoRules . idSpecialisation) exp_ids binds' = concatMap zap binds |