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| author | simonpj@microsoft.com <unknown> | 2006-12-06 07:18:45 +0000 |
|---|---|---|
| committer | simonpj@microsoft.com <unknown> | 2006-12-06 07:18:45 +0000 |
| commit | 94cbe022cbe18c2ae8da829d39c0896d615f8f1c (patch) | |
| tree | 1c6fd5cb3303f1e0f189ceab930a938c8440b034 /compiler/simplCore | |
| parent | b55fe864599e77f2ae2a3fbeec899ea7aeeac9f2 (diff) | |
| download | haskell-94cbe022cbe18c2ae8da829d39c0896d615f8f1c.tar.gz | |
Improve dependency analysis; makes more dictionaries inlinable
I recentl changed the scoring system used by dependency analysis for
recursive bindings, that it used the *form* of the RHS of a binding,
rather than just its type. In doing so I inadvertently made recursive
dictionary bindings unravel less well, because I'd missed the case
of c = /\a. C (...) (...)
This patch fixes the problem. A good example is the instance for
Monad (ST s) or Show (ST s a) in GHC.ST. It's vital for these
dictionaries to be inlinable.
Diffstat (limited to 'compiler/simplCore')
| -rw-r--r-- | compiler/simplCore/OccurAnal.lhs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/simplCore/OccurAnal.lhs b/compiler/simplCore/OccurAnal.lhs index 8b3d45e8e0..fc9104fb22 100644 --- a/compiler/simplCore/OccurAnal.lhs +++ b/compiler/simplCore/OccurAnal.lhs @@ -328,8 +328,13 @@ reOrderCycle bndrs (bind : binds) -- But we won't because constructor args are marked "Many". -- Cheap and cheerful; the simplifer moves casts out of the way + -- The lambda case is important to spot x = /\a. C (f a) + -- which comes up when C is a dictionary constructor and + -- f is a default method. + -- Example: the instance for Show (ST s a) in GHC.ST is_con_app (Var v) = isDataConWorkId v is_con_app (App f _) = is_con_app f + is_con_app (Lam b e) | isTyVar b = is_con_app e is_con_app (Note _ e) = is_con_app e is_con_app other = False |