[commit: ghc] supercompiler: Small simplification to solving loop predecessors map (c57f638)
Max Bolingbroke <[email protected]>
| Newsgroups | gmane.comp.lang.haskell.cvs.ghc |
|---|---|
| Message-ID | <[email protected]> |
Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : supercompiler http://hackage.haskell.org/trac/ghc/changeset/c57f6389a045ecb12c34059f379cafc3301824a4 >--------------------------------------------------------------- commit c57f6389a045ecb12c34059f379cafc3301824a4 Author: Max Bolingbroke <[email protected]> Date: Mon Jul 23 13:56:25 2012 +0100 Small simplification to solving loop predecessors map >--------------------------------------------------------------- compiler/supercompile/Supercompile/Drive/Split2.hs | 13 ++++++++----- 1 files changed, 8 insertions(+), 5 deletions(-) diff --git a/compiler/supercompile/Supercompile/Drive/Split2.hs b/compiler/supercompile/Supercompile/Drive/Split2.hs index 5ceee10..059afcc 100644 --- a/compiler/supercompile/Supercompile/Drive/Split2.hs +++ b/compiler/supercompile/Supercompile/Drive/Split2.hs @@ -516,7 +516,7 @@ solve generalised = M.keysSet . go_graph go_graph = uncurry (flip $ go M.empty) . sccs -- NB: the input list is ascending, so lower indexes come first, so we process all predecessors of a SCC before the SCC itself - go :: M.Map Context (M.Map Context (Maybe Context)) -- Successor |-> Predecessor |-> Just context (iff you end up in a *single* context by inlining along this edge, and which context that is). INVARIANT: no empty maps in range of first mapping + go :: M.Map Context (Maybe Context) -- Successor |-> Just context (iff you end up in a *single* context by inlining into all predecessors, and which context that is). -> IM.IntMap (LGraph Context Entries) -- Information about the internal structure of each SCC -> [(Int, M.Map Int (M.Map (Context, Context) Entries))] -- Topologically sorted SCC graph -> M.Map Context Context -- Marked contexts, mapped to the context they will end up in after inlining @@ -539,7 +539,7 @@ solve generalised = M.keysSet . go_graph -- induction step. We NEVER want to mark such a node. True -> M.empty -- SCC has predecessors - False | Just (Just common_ctxt) <- the_maybe $ concatMap M.elems (M.elems predecessors_here) + False | Just common_ctxt <- foldr1 plusContext $ M.elems predecessors_here , S.null (M.keysSet scc `S.intersection` generalised) -- Inlining along *all* of the predecessors for *all* of the entry points arrives at a -- common destination, and all of the SCC nodes are ungeneralised, so we can mark the whole SCC. @@ -558,9 +558,8 @@ solve generalised = M.keysSet . go_graph -- predecessor in a previous SCC have been force unmarked -> go_graph scc_cut - -- NB: this must be careful to preserve the predecessors invariant - predecessors' = foldr (uncurry $ M.insertWith unionDisjoint) predecessors - [ (ctxt', M.singleton ctxt mb_destination) + predecessors' = foldr (uncurry $ M.insertWith plusContext) predecessors + [ (ctxt', mb_destination) | external_ens' <- M.elems external_ens , ((ctxt, ctxt'), ent) <- M.toList external_ens' , let mb_destination | Just dest_ctxt <- M.lookup ctxt marks' = Just dest_ctxt -- Marked, inherits final context (NB: in this case the edge annotation is irrelevant) @@ -568,6 +567,10 @@ solve generalised = M.keysSet . go_graph | otherwise = Just ctxt -- Not marked, so any inlining (which would not duplicate work) stops here ] +plusContext :: Maybe Context -> Maybe Context -> Maybe Context +plusContext (Just c1) (Just c2) | c1 == c2 = Just c1 +plusContext _ _ = Nothing + splitFocus :: InScopeSet -> PushFocus (Anned QA) (In AnnedTerm) -> Generalised -> (LGraph Context Entries, PureHeap -> IM.IntMap Stack -> PushedFocus) splitFocus ids (QAFocus qa) True = splitQA ids qa