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| author | Bartosz Nitka <niteria@gmail.com> | 2016-05-24 04:44:37 -0700 |
|---|---|---|
| committer | Bartosz Nitka <niteria@gmail.com> | 2016-05-24 05:43:12 -0700 |
| commit | 9d06ef1ae451a145607301dc7556931b537a7d83 (patch) | |
| tree | 9385f43159fb1c7ddda5bb2e20107eaa7b8f3c3f /compiler/utils/UniqDFM.hs | |
| parent | 4c6e69d58a300d6ef440d326a3fd29b58b284fa1 (diff) | |
| download | haskell-9d06ef1ae451a145607301dc7556931b537a7d83.tar.gz | |
Make Arrow desugaring deterministic
This kills two instances of varSetElems that turned out to be
nondeterministic. I've tried to untangle this before, but it's
a bit hard with the fixDs in the middle. Fortunately I now have
a test case that proves that we need determinism here.
Test Plan: ./validate, new testcase
Reviewers: simonpj, simonmar, austin, bgamari
Reviewed By: bgamari
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D2258
GHC Trac Issues: #4012
Diffstat (limited to 'compiler/utils/UniqDFM.hs')
| -rw-r--r-- | compiler/utils/UniqDFM.hs | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/compiler/utils/UniqDFM.hs b/compiler/utils/UniqDFM.hs index 4bd97ef2eb..91fb0ecbec 100644 --- a/compiler/utils/UniqDFM.hs +++ b/compiler/utils/UniqDFM.hs @@ -42,7 +42,7 @@ module UniqDFM ( filterUDFM, isNullUDFM, sizeUDFM, - intersectUDFM, + intersectUDFM, udfmIntersectUFM, intersectsUDFM, disjointUDFM, disjointUdfmUfm, minusUDFM, @@ -275,6 +275,11 @@ intersectUDFM (UDFM x i) (UDFM y _j) = UDFM (M.intersection x y) i -- M.intersection is left biased, that means the result will only have -- a subset of elements from the left set, so `i` is a good upper bound. +udfmIntersectUFM :: UniqDFM elt -> UniqFM elt -> UniqDFM elt +udfmIntersectUFM (UDFM x i) y = UDFM (M.intersection x (ufmToIntMap y)) i + -- M.intersection is left biased, that means the result will only have + -- a subset of elements from the left set, so `i` is a good upper bound. + intersectsUDFM :: UniqDFM elt -> UniqDFM elt -> Bool intersectsUDFM x y = isNullUDFM (x `intersectUDFM` y) |