-
-{-
-\subsection{Backward problems}
-
-In a backward problem, we compute \emph{in} facts from \emph{out}
-facts. The analysis gives us [[exit_in]], [[last_in]], [[middle_in]],
-and [[first_in]], each of which computes an \emph{in} fact for one
-kind of node. We provide [[head_in]], which computes the \emph{in}
-fact for a first node followed by zero or more middle nodes.
-
-We don't compute and return the \emph{in} fact for block; instead, we
-use [[setFact]] to attach that fact to the block's unique~ID.
-We iterate until no more facts have changed.
--}
-run_b_anal comp graph =
- refine_b_anal comp graph (return ())
- -- for a backward analysis, everything is initially bottom
-
-refine_b_anal comp graph initial =
- run "backward" (bc_name comp) initial set_block_fact () blocks
- where
- blocks = reverse (postorder_dfs graph)
- set_block_fact () b@(G.Block id _) =
- let (h, l) = G.goto_end (G.unzip b) in
- do env <- factsEnv
- let block_in = head_in h (last_in comp env l) -- 'in' fact for the block
- setFact id block_in
- head_in (G.ZHead h m) out = head_in h (bc_middle_in comp out m)
- head_in (G.ZFirst id) out = bc_first_in comp out id
-
-last_in :: BComputation m l i o -> (BlockId -> i) -> G.ZLast l -> o
-last_in comp env (G.LastOther l) = bc_last_in comp env l
-last_in comp _ (G.LastExit) = bc_exit_in comp
-
------- we can now pass those facts elsewhere
-fold_edge_facts_b f comp graph env z =
- foldl fold_block_facts z (postorder_dfs graph)
- where
- fold_block_facts z b =
- let (h, l) = G.goto_end (G.unzip b)
- in head_fold h (last_in comp env l) z
- head_fold (G.ZHead h m) out z = head_fold h (bc_middle_in comp out m) (f out z)
- head_fold (G.ZFirst id) out z = f (bc_first_in comp out id) (f out z)
-
-fold_edge_facts_with_nodes_b fl fm ff comp graph env z =
- foldl fold_block_facts z (postorder_dfs graph)
- where
- fold_block_facts z b =
- let (h, l) = G.goto_end (G.unzip b)
- in' = last_in comp env l
- z' = case l of { G.LastExit -> z ; G.LastOther l -> fl l in' z }
- in head_fold h in' z'
- head_fold (G.ZHead h m) out z =
- let a = bc_middle_in comp out m
- z' = fm m a z
- in head_fold h a z'
- head_fold (G.ZFirst id) out z =
- let a = bc_first_in comp out id
- z' = ff id a z
- in z'
-
-
--- | In the general case we solve a graph in the context of a larger subgraph.
--- To do this, we need a locally modified computation that allows an
--- ``exit fact'' to flow into the exit node.
-
-comp_with_exit_b :: BComputation m l i (OptimizationFuel -> DFM f (Answer m l o)) -> o ->
- BComputation m l i (OptimizationFuel -> DFM f (Answer m l o))
-comp_with_exit_b comp exit_fact =
- comp { bc_exit_in = \_fuel -> return $ Dataflow $ exit_fact }
-
--- | Given this function, we can now solve a graph simply by doing a
--- backward analysis on the modified computation. Note we have to be
--- very careful with 'Rewrite'. Either a rewrite is going to
--- participate, in which case we mark the graph rerewritten, or we're
--- going to analysis the proposed rewrite and then throw away
--- everything but the answer, in which case it's a 'subAnalysis'. A
--- Rewrite should always use exactly one of these monadic operations.
-
-solve_graph_b ::
- (DebugNodes m l, Outputable a) =>
- BPass m l a -> OptimizationFuel -> G.LGraph m l -> a -> DFM a (OptimizationFuel, a)
-solve_graph_b comp fuel graph exit_fact =
- general_backward (comp_with_exit_b comp exit_fact) fuel graph
- where
- -- general_backward :: BPass m l a -> OptimizationFuel -> G.LGraph m l -> DFM a (OptimizationFuel, a)
- general_backward comp fuel graph =
- let -- set_block_fact :: OptimizationFuel -> G.Block m l -> DFM a OptimizationFuel
- set_block_fact fuel b =
- do { (fuel, block_in) <-
- let (h, l) = G.goto_end (G.unzip b) in
- factsEnv >>= \env -> last_in comp env l fuel >>= \x ->
- case x of
- Dataflow a -> head_in fuel h a
- Rewrite g ->
- do { bot <- botFact
- ; (fuel, a) <- subAnalysis' $
- solve_graph_b_g comp (fuel-1) g bot
- ; head_in fuel h a }
- ; my_trace "result of" (text (bc_name comp) <+>
- text "on" <+> ppr (G.blockId b) <+> text "is" <+> ppr block_in) $
- setFact (G.blockId b) block_in
- ; return fuel
- }
- head_in fuel (G.ZHead h m) out =
- bc_middle_in comp out m fuel >>= \x -> case x of
- Dataflow a -> head_in fuel h a
- Rewrite g ->
- do { (fuel, a) <- subAnalysis' $ solve_graph_b_g comp (fuel-1) g out
- ; my_trace "Rewrote middle node"
- (f4sep [ppr m, text "to", pprGraph g]) $
- head_in fuel h a }
- head_in fuel (G.ZFirst id) out =
- bc_first_in comp out id fuel >>= \x -> case x of
- Dataflow a -> return (fuel, a)
- Rewrite g -> do { subAnalysis' $ solve_graph_b_g comp (fuel-1) g out }
-
- in do { fuel <-
- run "backward" (bc_name comp) (return ()) set_block_fact fuel blocks
- ; a <- getFact (G.lg_entry graph)
- ; facts <- allFacts
- ; my_trace "Solution to graph after pass 1 is" (pprFacts graph facts a) $
- return (fuel, a) }
-
- blocks = reverse (G.postorder_dfs graph)
- pprFacts g env a = (ppr a <+> text "with") $$ vcat (pprLgraph g : map pprFact (ufmToList env))
- pprFact (id, a) = hang (ppr id <> colon) 4 (ppr a)
-
-solve_graph_b_g ::
- (DebugNodes m l, Outputable a) =>
- BPass m l a -> OptimizationFuel -> G.Graph m l -> a -> DFM a (OptimizationFuel, a)
-solve_graph_b_g comp fuel graph exit_fact =
- do { g <- lgraphOfGraph graph ; solve_graph_b comp fuel g exit_fact }
-
-
-lgraphOfGraph :: G.Graph m l -> DFM f (G.LGraph m l)
-lgraphOfGraph g =
- do id <- freshBlockId "temporary id for dataflow analysis"
- return $ labelGraph id g
-
-labelGraph :: BlockId -> G.Graph m l -> G.LGraph m l
-labelGraph id (Graph tail blocks) = LGraph id (insertBlock (Block id tail) blocks)
-
--- | We can remove the entry label of an LGraph and remove
--- it, leaving a Graph. Notice that this operation is NOT SAFE if a
--- block within the LGraph branches to the entry point. It should
--- be used only to complement 'lgraphOfGraph' above.
-
-remove_entry_label :: LGraph m l -> Graph m l
-remove_entry_label g =
- let FGraph e (ZBlock (ZFirst id) tail) others = entry g
- in ASSERT (id == e) Graph tail others
-
-{-
-We solve and rewrite in two passes: the first pass iterates to a fixed
-point to reach a dataflow solution, and the second pass uses that
-solution to rewrite the graph.
-
-The
-key job is done by [[propagate]], which propagates a fact of type~[[a]]
-between a head and tail.
-The tail is in final form; the head is still to be rewritten.
--}
-
-solve_and_rewrite_b ::
- (DebugNodes m l, Outputable a) =>
- BPass m l a -> OptimizationFuel -> LGraph m l -> a -> DFM a (OptimizationFuel, a, LGraph m l)
-solve_and_rewrite_b_graph ::
- (DebugNodes m l, Outputable a) =>
- BPass m l a -> OptimizationFuel -> Graph m l -> a -> DFM a (OptimizationFuel, a, Graph m l)
-
-
-solve_and_rewrite_b comp fuel graph exit_fact =
- do { (_, a) <- solve_graph_b comp fuel graph exit_fact -- pass 1
- ; facts <- allFacts
- ; (fuel, g) <- -- pass 2
- my_trace "Solution to graph after pass 1 is" (pprFacts graph facts) $
- backward_rewrite (comp_with_exit_b comp exit_fact) fuel graph
- ; facts <- allFacts
- ; my_trace "Rewritten graph after pass 2 is" (pprFacts g facts) $
- return (fuel, a, g) }
- where
- pprFacts g env = vcat (pprLgraph g : map pprFact (ufmToList env))
- pprFact (id, a) = hang (ppr id <> colon) 4 (ppr a)
- eid = G.lg_entry graph
- backward_rewrite comp fuel graph =
- rewrite_blocks comp fuel emptyBlockEnv $ reverse (G.postorder_dfs graph)
- -- rewrite_blocks ::
- -- BPass m l a -> OptimizationFuel ->
- -- BlockEnv (Block m l) -> [Block m l] -> DFM a (OptimizationFuel,G.LGraph m l)
- rewrite_blocks _comp fuel rewritten [] = return (fuel, G.LGraph eid rewritten)
- rewrite_blocks comp fuel rewritten (b:bs) =
- let rewrite_next_block fuel =
- let (h, l) = G.goto_end (G.unzip b) in
- factsEnv >>= \env -> last_in comp env l fuel >>= \x -> case x of
- Dataflow a -> propagate fuel h a (G.ZLast l) rewritten
- Rewrite g ->
- do { markGraphRewritten
- ; bot <- botFact
- ; (fuel, a, g') <- solve_and_rewrite_b_graph comp (fuel-1) g bot
- ; let G.Graph t new_blocks = g'
- ; let rewritten' = new_blocks `plusUFM` rewritten
- ; propagate fuel h a t rewritten' -- continue at entry of g'
- }
- -- propagate :: OptimizationFuel -- Number of rewrites permitted
- -- -> G.ZHead m -- Part of current block yet to be rewritten
- -- -> a -- Fact on edge between head and tail
- -- -> G.ZTail m l -- Part of current block already rewritten
- -- -> BlockEnv (Block m l) -- Blocks already rewritten
- -- -> DFM a (OptimizationFuel, G.LGraph m l)
- propagate fuel (G.ZHead h m) out tail rewritten =
- bc_middle_in comp out m fuel >>= \x -> case x of
- Dataflow a -> propagate fuel h a (G.ZTail m tail) rewritten
- Rewrite g ->
- do { markGraphRewritten
- ; (fuel, a, g') <- solve_and_rewrite_b_graph comp (fuel-1) g out
- ; let G.Graph t newblocks = G.splice_tail g' tail
- ; my_trace "Rewrote middle node"
- (f4sep [ppr m, text "to", pprGraph g']) $
- propagate fuel h a t (newblocks `plusUFM` rewritten) }
- propagate fuel h@(G.ZFirst id) out tail rewritten =
- bc_first_in comp out id fuel >>= \x -> case x of
- Dataflow a ->
- let b = G.Block id tail in
- do { checkFactMatch id a
- ; rewrite_blocks comp fuel (extendBlockEnv rewritten id b) bs }
- Rewrite g ->
- do { markGraphRewritten
- ; (fuel, a, g') <- solve_and_rewrite_b_graph comp (fuel-1) g out
- ; let G.Graph t newblocks = G.splice_tail g' tail
- ; my_trace "Rewrote label " (f4sep [ppr id,text "to",pprGraph g])$
- propagate fuel h a t (newblocks `plusUFM` rewritten) }
- in rewrite_next_block fuel
-
-{- Note [Rewriting labelled LGraphs]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-It's hugely annoying that we get in an LGraph and in order to solve it
-we have to slap on a new label which we then immediately strip off.
-But the alternative is to have all the iterative solvers work on
-Graphs, and then suddenly instead of a single case (ZBlock) every
-solver has to deal with two cases (ZBlock and ZTail). So until
-somebody comes along who is smart enough to do this and still leave
-the code understandable for mortals, it stays as it is.
-
-(One part of the solution will be postorder_dfs_from_except.)
--}
-
-solve_and_rewrite_b_graph comp fuel graph exit_fact =
- do g <- lgraphOfGraph graph
- (fuel, a, g') <- solve_and_rewrite_b comp fuel g exit_fact
- return (fuel, a, remove_entry_label g')
-
-b_rewrite comp g =
- do { fuel <- liftTx txRemaining
- ; bot <- botFact
- ; (fuel', _, gc) <- solve_and_rewrite_b comp fuel g bot
- ; liftTx $ txDecrement (bc_name comp) fuel fuel'
- ; return gc
- }
-
-{-
-This debugging stuff is left over from imperative-land.
-It might be useful one day if I learn how to cheat the IO monad!
-
-debug_b :: (Outputable m, Outputable l, Outputable a) => BPass m l a -> BPass m l a
-
-let debug s (f, comp) =
- let pr = Printf.eprintf in
- let fact dir node a = pr "%s %s for %s = %s\n" f.fact_name dir node (s a) in
- let rewr node g = pr "%s rewrites %s to <not-shown>\n" comp.name node in
- let wrap f nodestring node fuel =
- let answer = f node fuel in
- let () = match answer with
- | Dataflow a -> fact "in " (nodestring node) a
- | Rewrite g -> rewr (nodestring node) g in
- answer in
- let wrapout f nodestring out node fuel =
- fact "out" (nodestring node) out;
- wrap (f out) nodestring node fuel in
- let last_in = wrap comp.last_in (RS.rtl << G.last_instr) in
- let middle_in = wrapout comp.middle_in (RS.rtl << G.mid_instr) in
- let first_in =
- let first = function G.Entry -> "<entry>" | G.Label ((u, l), _, _) -> l in
- wrapout comp.first_in first in
- f, { comp with last_in = last_in; middle_in = middle_in; first_in = first_in; }
--}
-
-anal_b comp = comp { bc_last_in = wrap2 $ bc_last_in comp
- , bc_exit_in = wrap0 $ bc_exit_in comp
- , bc_middle_in = wrap2 $ bc_middle_in comp
- , bc_first_in = wrap2 $ bc_first_in comp }
- where wrap2 f out node _fuel = return $ Dataflow (f out node)
- wrap0 fact _fuel = return $ Dataflow fact
-
-ignore_transactions_b comp =
- comp { bc_last_in = wrap2 $ bc_last_in comp
- , bc_exit_in = wrap0 $ bc_exit_in comp
- , bc_middle_in = wrap2 $ bc_middle_in comp
- , bc_first_in = wrap2 $ bc_first_in comp }
- where wrap2 f out node _fuel = f out node
- wrap0 fact _fuel = fact
-
-answer' :: (b -> DFM f (Graph m l)) -> OptimizationFuel -> Maybe b -> a -> DFM f (Answer m l a)
-answer' lift fuel r a =
- case r of Just gc | fuel > 0 -> do { g <- lift gc; return $ Rewrite g }
- _ -> return $ Dataflow a
-
-unlimited_answer'
- :: (b -> DFM f (Graph m l)) -> OptimizationFuel -> Maybe b -> a -> DFM f (Answer m l a)
-unlimited_answer' lift _fuel r a =
- case r of Just gc -> do { g <- lift gc; return $ Rewrite g }
- _ -> return $ Dataflow a
-
-combine_a_t_with :: (OptimizationFuel -> Maybe b -> a -> DFM a (Answer m l a)) ->
- BAnalysis m l a -> BComputation m l a (Maybe b) ->
- BPass m l a
-combine_a_t_with answer anal tx =
- let last_in env l fuel =
- answer fuel (bc_last_in tx env l) (bc_last_in anal env l)
- exit_in fuel = answer fuel (bc_exit_in tx) (bc_exit_in anal)
- middle_in out m fuel =
- answer fuel (bc_middle_in tx out m) (bc_middle_in anal out m)
- first_in out f fuel =
- answer fuel (bc_first_in tx out f) (bc_first_in anal out f)
- in BComp { bc_name = concat [bc_name anal, " and ", bc_name tx]
- , bc_last_in = last_in, bc_middle_in = middle_in
- , bc_first_in = first_in, bc_exit_in = exit_in }
-
-a_t_b = combine_a_t_with (answer' liftUSM)
-a_ft_b = combine_a_t_with (answer' return)
-a_ft_b_unlimited = combine_a_t_with (unlimited_answer' return)
-
-
--- =============== FORWARD ================
-
--- | We don't compute and return the \emph{in} fact for block; instead, we
--- use [[P.set]] to attach that fact to the block's unique~ID.
--- We iterate until no more facts have changed.
-
-dump_things :: Bool
-dump_things = False
-
-my_trace :: String -> SDoc -> a -> a
-my_trace = if dump_things then pprTrace else \_ _ a -> a
-
-run_f_anal comp entry_fact graph = refine_f_anal comp graph set_entry
- where set_entry = setFact (G.lg_entry graph) entry_fact
-
-refine_f_anal comp graph initial =
- run "forward" (fc_name comp) initial set_successor_facts () blocks
- where blocks = G.postorder_dfs graph
- set_successor_facts () (G.Block id t) =
- let forward in' (G.ZTail m t) = forward (fc_middle_out comp in' m) t
- forward in' (G.ZLast l) = setEdgeFacts (last_outs comp in' l)
- _blockname = if id == G.lg_entry graph then "<entry>" else show id
- in getFact id >>= \a -> forward (fc_first_out comp a id) t
- setEdgeFacts (LastOutFacts fs) = mapM_ setEdgeFact fs
- setEdgeFact (id, a) = setFact id a
-
-last_outs :: FComputation m l i om ol -> i -> G.ZLast l -> ol
-last_outs comp i (G.LastExit) = fc_exit_outs comp i
-last_outs comp i (G.LastOther l) = fc_last_outs comp i l
-
--- | In the general case we solve a graph in the context of a larger subgraph.
--- To do this, we need a locally modified computation that allows an
--- ``exit fact'' to flow out of the exit node. We pass in a fresh BlockId
--- to which the exit fact can flow
-
-comp_with_exit_f :: FPass m l a -> BlockId -> FPass m l a
-comp_with_exit_f comp exit_fact_id = comp { fc_exit_outs = exit_outs }
- where exit_outs in' _fuel = return $ Dataflow $ LastOutFacts [(exit_fact_id, in')]
-
--- | Given [[comp_with_exit_f]], we can now solve a graph simply by doing a
--- forward analysis on the modified computation.
-solve_graph_f ::
- (DebugNodes m l, Outputable a) =>
- FPass m l a -> OptimizationFuel -> G.LGraph m l -> a ->
- DFM a (OptimizationFuel, a, LastOutFacts a)
-solve_graph_f comp fuel g in_fact =
- do { exit_fact_id <- freshBlockId "proxy for exit node"
- ; fuel <- general_forward (comp_with_exit_f comp exit_fact_id) fuel in_fact g
- ; a <- getFact exit_fact_id
- ; outs <- lastOutFacts
- ; forgetFact exit_fact_id -- close space leak
- ; return (fuel, a, LastOutFacts outs) }
- where
- -- general_forward :: FPass m l a -> OptimizationFuel -> a -> G.LGraph m l -> DFM a OptimizationFuel
- general_forward comp fuel entry_fact graph =
- let blocks = G.postorder_dfs g
- is_local id = isJust $ lookupBlockEnv (G.lg_blocks g) id
- -- set_or_save :: LastOutFacts a -> DFM a ()
- set_or_save (LastOutFacts l) = mapM_ set_or_save_one l
- set_or_save_one (id, a) =
- if is_local id then setFact id a else addLastOutFact (id, a)
- set_entry = setFact (G.lg_entry graph) entry_fact
-
- set_successor_facts fuel b =
- let set_tail_facts fuel in' (G.ZTail m t) =
- my_trace "Solving middle node" (ppr m) $
- fc_middle_out comp in' m fuel >>= \ x -> case x of
- Dataflow a -> set_tail_facts fuel a t
- Rewrite g ->
- do (fuel, out, last_outs) <-
- subAnalysis' $ solve_graph_f_g comp (fuel-1) g in'
- set_or_save last_outs
- set_tail_facts fuel out t
- set_tail_facts fuel in' (G.ZLast l) =
- last_outs comp in' l fuel >>= \x -> case x of
- Dataflow outs -> do { set_or_save outs; return fuel }
- Rewrite g ->
- do (fuel, _, last_outs) <-
- subAnalysis' $ solve_graph_f_g comp (fuel-1) g in'
- set_or_save last_outs
- return fuel
- G.Block id t = b
- in do idfact <- getFact id
- infact <- fc_first_out comp idfact id fuel
- case infact of Dataflow a -> set_tail_facts fuel a t
- Rewrite g ->
- do (fuel, out, last_outs) <- subAnalysis' $
- solve_graph_f_g comp (fuel-1) g idfact
- set_or_save last_outs
- set_tail_facts fuel out t
- in run "forward" (fc_name comp) set_entry set_successor_facts fuel blocks
-
-solve_graph_f_g ::
- (DebugNodes m l, Outputable a) =>
- FPass m l a -> OptimizationFuel -> G.Graph m l -> a ->
- DFM a (OptimizationFuel, a, LastOutFacts a)
-solve_graph_f_g comp fuel graph in_fact =
- do { g <- lgraphOfGraph graph ; solve_graph_f comp fuel g in_fact }
-
-
-{-
-We solve and rewrite in two passes: the first pass iterates to a fixed
-point to reach a dataflow solution, and the second pass uses that
-solution to rewrite the graph.
-
-The key job is done by [[propagate]], which propagates a fact of type~[[a]]
-between a head and tail.
-The tail is in final form; the head is still to be rewritten.
--}
-solve_and_rewrite_f ::
- (DebugNodes m l, Outputable a) =>
- FPass m l a -> OptimizationFuel -> LGraph m l -> a ->
- DFM a (OptimizationFuel, a, LGraph m l)
-solve_and_rewrite_f comp fuel graph in_fact =
- do solve_graph_f comp fuel graph in_fact -- pass 1
- exit_id <- freshBlockId "proxy for exit node"
- (fuel, g) <- forward_rewrite (comp_with_exit_f comp exit_id) fuel graph in_fact
- exit_fact <- getFact exit_id
- return (fuel, exit_fact, g)
-
-solve_and_rewrite_f_graph ::
- (DebugNodes m l, Outputable a) =>
- FPass m l a -> OptimizationFuel -> Graph m l -> a ->
- DFM a (OptimizationFuel, a, Graph m l)
-solve_and_rewrite_f_graph comp fuel graph in_fact =
- do g <- lgraphOfGraph graph
- (fuel, a, g') <- solve_and_rewrite_f comp fuel g in_fact
- return (fuel, a, remove_entry_label g')
-
-forward_rewrite ::
- (DebugNodes m l, Outputable a) =>
- FPass m l a -> OptimizationFuel -> G.LGraph m l -> a ->
- DFM a (OptimizationFuel, G.LGraph m l)
-forward_rewrite comp fuel graph entry_fact =
- do setFact eid entry_fact
- rewrite_blocks fuel emptyBlockEnv (G.postorder_dfs graph)
- where
- eid = G.lg_entry graph
- is_local id = isJust $ lookupBlockEnv (G.lg_blocks graph) id
- -- set_or_save :: LastOutFacts a -> DFM a ()
- set_or_save (LastOutFacts l) = mapM_ set_or_save_one l
- set_or_save_one (id, a) =
- if is_local id then checkFactMatch id a
- else panic "set fact outside graph during rewriting pass?!"
-
- -- rewrite_blocks ::
- -- OptimizationFuel -> BlockEnv (Block m l) -> [Block m l] -> DFM a (OptimizationFuel, LGraph m l)
- rewrite_blocks fuel rewritten [] = return (fuel, G.LGraph eid rewritten)
- rewrite_blocks fuel rewritten (G.Block id t : bs) =
- do id_fact <- getFact id
- first_out <- fc_first_out comp id_fact id fuel
- case first_out of
- Dataflow a -> propagate fuel (G.ZFirst id) a t rewritten bs
- Rewrite g -> do { markGraphRewritten
- ; rewrite_blocks (fuel-1) rewritten
- (G.postorder_dfs (labelGraph id g) ++ bs) }
- -- propagate :: OptimizationFuel -> G.ZHead m -> a -> G.ZTail m l -> BlockEnv (G.Block m l) ->
- -- [G.Block m l] -> DFM a (OptimizationFuel, G.LGraph m l)
- propagate fuel h in' (G.ZTail m t) rewritten bs =
- my_trace "Rewriting middle node" (ppr m) $
- do fc_middle_out comp in' m fuel >>= \x -> case x of
- Dataflow a -> propagate fuel (G.ZHead h m) a t rewritten bs
- Rewrite g ->
- do markGraphRewritten
- (fuel, a, g) <- solve_and_rewrite_f_graph comp (fuel-1) g in'
- let (blocks, h') = G.splice_head' h g
- propagate fuel h' a t (blocks `plusUFM` rewritten) bs
- propagate fuel h in' (G.ZLast l) rewritten bs =
- do last_outs comp in' l fuel >>= \x -> case x of
- Dataflow outs ->
- do set_or_save outs
- let b = G.zip (G.ZBlock h (G.ZLast l))
- rewrite_blocks fuel (G.insertBlock b rewritten) bs
- Rewrite g ->
- do markGraphRewritten
- (fuel, _, g) <- solve_and_rewrite_f_graph comp (fuel-1) g in'
- let g' = G.splice_head_only' h g
- rewrite_blocks fuel (G.lg_blocks g' `plusUFM` rewritten) bs
-
-f_rewrite comp entry_fact g =
- do { fuel <- liftTx txRemaining
- ; (fuel', _, gc) <- solve_and_rewrite_f comp fuel g entry_fact
- ; liftTx $ txDecrement (fc_name comp) fuel fuel'
- ; return gc
- }
-
-
-{-
-debug_f :: (Outputable m, Outputable l, Outputable a) => FPass m l a -> FPass m l a
-
-let debug s (f, comp) =
- let pr = Printf.eprintf in
- let fact dir node a = pr "%s %s for %s = %s\n" f.fact_name dir node (s a) in
- let setter dir node run_sets set =
- run_sets (fun u a -> pr "%s %s for %s = %s\n" f.fact_name dir node (s a); set u a) in
- let rewr node g = pr "%s rewrites %s to <not-shown>\n" comp.name node in
- let wrap f nodestring wrap_answer in' node fuel =
- fact "in " (nodestring node) in';
- wrap_answer (nodestring node) (f in' node fuel)
- and wrap_fact n answer =
- let () = match answer with
- | Dataflow a -> fact "out" n a
- | Rewrite g -> rewr n g in
- answer
- and wrap_setter n answer =
- match answer with
- | Dataflow set -> Dataflow (setter "out" n set)
- | Rewrite g -> (rewr n g; Rewrite g) in
- let middle_out = wrap comp.middle_out (RS.rtl << G.mid_instr) wrap_fact in
- let last_outs = wrap comp.last_outs (RS.rtl << G.last_instr) wrap_setter in
- f, { comp with last_outs = last_outs; middle_out = middle_out; }
--}
-
-anal_f comp = comp { fc_first_out = wrap2 $ fc_first_out comp
- , fc_middle_out = wrap2 $ fc_middle_out comp
- , fc_last_outs = wrap2 $ fc_last_outs comp
- , fc_exit_outs = wrap1 $ fc_exit_outs comp
- }
- where wrap2 f out node _fuel = return $ Dataflow (f out node)
- wrap1 f fact _fuel = return $ Dataflow (f fact)
-
-
-a_t_f anal tx =
- let answer = answer' liftUSM
- first_out in' id fuel =
- answer fuel (fc_first_out tx in' id) (fc_first_out anal in' id)
- middle_out in' m fuel =
- answer fuel (fc_middle_out tx in' m) (fc_middle_out anal in' m)
- last_outs in' l fuel =
- answer fuel (fc_last_outs tx in' l) (fc_last_outs anal in' l)
- exit_outs in' fuel = undefined
- answer fuel (fc_exit_outs tx in') (fc_exit_outs anal in')
- in FComp { fc_name = concat [fc_name anal, " and ", fc_name tx]
- , fc_last_outs = last_outs, fc_middle_out = middle_out
- , fc_first_out = first_out, fc_exit_outs = exit_outs }