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| author | Bartosz Nitka <niteria@gmail.com> | 2016-05-11 07:47:47 -0700 |
|---|---|---|
| committer | Bartosz Nitka <niteria@gmail.com> | 2016-05-11 07:47:50 -0700 |
| commit | 3edbd091341ab0ab60862ba18d3107f34c7fc876 (patch) | |
| tree | e5497ddfaf4e827549c4a02c6ae1d3453b83634f /compiler/utils/UniqFM.hs | |
| parent | 0e719885f53e20f2e14a94b32d858b47b516a8fc (diff) | |
| download | haskell-3edbd091341ab0ab60862ba18d3107f34c7fc876.tar.gz | |
Document SCC determinism
I've documented the guarantees that stronglyConnCompFromEdgedVertices
provides and commented on the call sites to explain why they are
OK from determinism standpoint. I've changed the functions to
nonDetUFM versions, so that it's explicit they could introduce
nondeterminism. I haven't defined container (VarSet, NameSet)
specific versions, so that we have less functions to worry about.
Test Plan: this is mostly just documentation,
it should have no runtime effect
Reviewers: bgamari, simonmar, austin, simonpj
Reviewed By: simonpj
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D2194
GHC Trac Issues: #4012
Diffstat (limited to 'compiler/utils/UniqFM.hs')
| -rw-r--r-- | compiler/utils/UniqFM.hs | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/compiler/utils/UniqFM.hs b/compiler/utils/UniqFM.hs index 590358ab40..2ff635268d 100644 --- a/compiler/utils/UniqFM.hs +++ b/compiler/utils/UniqFM.hs @@ -61,7 +61,7 @@ module UniqFM ( isNullUFM, lookupUFM, lookupUFM_Directly, lookupWithDefaultUFM, lookupWithDefaultUFM_Directly, - nonDetEltsUFM, eltsUFM, keysUFM, splitUFM, + nonDetEltsUFM, eltsUFM, nonDetKeysUFM, keysUFM, splitUFM, ufmToSet_Directly, ufmToList, ufmToIntMap, joinUFM, pprUniqFM, pprUFM, pluralUFM @@ -303,10 +303,18 @@ anyUFM p (UFM m) = M.fold ((||) . p) False m allUFM :: (elt -> Bool) -> UniqFM elt -> Bool allUFM p (UFM m) = M.fold ((&&) . p) True m --- See Note [Deterministic UniqFM] to learn about nondeterminism +-- See Note [Deterministic UniqFM] to learn about nondeterminism. +-- If you use this please provide a justification why it doesn't introduce +-- nondeterminism. nonDetEltsUFM :: UniqFM elt -> [elt] nonDetEltsUFM (UFM m) = M.elems m +-- See Note [Deterministic UniqFM] to learn about nondeterminism. +-- If you use this please provide a justification why it doesn't introduce +-- nondeterminism. +nonDetKeysUFM :: UniqFM elt -> [Unique] +nonDetKeysUFM (UFM m) = map getUnique $ M.keys m + ufmToIntMap :: UniqFM elt -> M.IntMap elt ufmToIntMap (UFM m) = m |