--- /dev/null
+{-# LANGUAGE MultiParamTypeClasses #-}
+module ZipDataflow0
+ ( Answer(..)
+ , BComputation(..), BAnalysis, BTransformation, BFunctionalTransformation
+ , BPass, BUnlimitedPass
+ , FComputation(..), FAnalysis, FTransformation, FFunctionalTransformation
+ , FPass, FUnlimitedPass
+ , LastOutFacts(..)
+ , DebugNodes
+ , anal_b, a_t_b, a_ft_b, a_ft_b_unlimited, ignore_transactions_b
+ , anal_f, a_t_f
+ , null_f_ft, null_b_ft
+ , run_b_anal, run_f_anal
+ , refine_f_anal, refine_b_anal, fold_edge_facts_b, fold_edge_facts_with_nodes_b
+ , b_rewrite, f_rewrite, b_shallow_rewrite, f_shallow_rewrite
+ , solve_graph_b, solve_graph_f
+ )
+where
+
+import CmmTx
+import DFMonad
+import ZipCfg
+import qualified ZipCfg as G
+
+import Outputable
+import Panic
+import UniqFM
+import UniqSupply
+
+import Control.Monad
+import Maybe
+
+#include "HsVersions.h"
+
+{-
+
+\section{A very polymorphic infrastructure for dataflow problems}
+
+This module presents a framework for solving iterative dataflow
+problems.
+There are two major submodules: one for forward problems and another
+for backward problems.
+Both modules incorporate the composition framework developed by
+Lerner, Grove, and Chambers.
+They also support a \emph{transaction limit}, which enables the
+binary-search debugging technique developed by Whalley and Davidson
+under the name \emph{vpoiso}.
+Transactions may either be known to the individual dataflow solvers or
+may be managed by the framework.
+-}
+
+-- | In the composition framework, a pass either produces a dataflow
+-- fact or proposes to rewrite the graph. To make life easy for the
+-- clients, the rewrite is given in unlabelled form, but we use
+-- labelled form internally throughout, because it greatly simplifies
+-- the implementation not to have the first block be a special case
+-- edverywhere.
+
+data Answer m l a = Dataflow a | Rewrite (Graph m l)
+
+
+{-
+
+============== Descriptions of dataflow passes} ================
+
+------ Passes for backward dataflow problemsa
+
+The computation of a fact is the basis of a dataflow pass.
+A computation takes *four* type parameters:
+
+ * 'middle' and 'last' are the types of the middle
+ and last nodes of the graph over which the dataflow
+ solution is being computed
+
+ * 'input' is an input, from which it should be possible to
+ derive a dataflow fact of interest. For example, 'input' might
+ be equal to a fact, or it might be a tuple of which one element
+ is a fact.
+
+ * 'output' is an output, or possibly a function from 'fuel' to an
+ output
+
+A computation is interesting for any pair of 'middle' and 'last' type
+parameters that can form a reasonable graph. But it is not useful to
+instantiate 'input' and 'output' arbitrarily. Rather, only certain
+combinations of instances are likely to be useful, such as those shown
+below.
+
+Backward analyses compute *in* facts (facts on inedges).
+-}
+
+-- A dataflow pass requires a name and a transfer function for each of
+-- four kinds of nodes:
+-- first (the BlockId),
+-- middle
+-- last
+-- LastExit
+
+-- A 'BComputation' describes a complete backward dataflow pass, as a
+-- record of transfer functions. Because the analysis works
+-- back-to-front, we write the exit node at the beginning.
+--
+-- So there is
+-- an 'input' for each out-edge of the node
+-- (hence (BlockId -> input) for bc_last_in)
+-- an 'output' for the in-edge of the node
+
+data BComputation middle last input output = BComp
+ { bc_name :: String
+ , bc_exit_in :: output
+ , bc_last_in :: (BlockId -> input) -> last -> output
+ , bc_middle_in :: input -> middle -> output
+ , bc_first_in :: input -> BlockId -> output
+ }
+
+-- | From these elements we build several kinds of passes:
+-- * A pure analysis computes a fact, using that fact as input and output.
+-- * A pure transformation computes no facts but only changes the graph.
+-- * A fully general pass both computes a fact and rewrites the graph,
+-- respecting the current transaction limit.
+--
+type BAnalysis m l a = BComputation m l a a
+type BTransformation m l a = BComputation m l a (Maybe (UniqSM (Graph m l)))
+type BFunctionalTransformation m l a = BComputation m l a (Maybe (Graph m l))
+ -- ToDo: consider replacing UniqSM (Graph l m) with (AGraph m l)
+
+type BPass m l a = BComputation m l a (OptimizationFuel -> DFM a (Answer m l a))
+type BUnlimitedPass m l a = BComputation m l a ( DFM a (Answer m l a))
+
+ -- (DFM a t) maintains the (BlockId -> a) map
+ -- ToDo: overlap with bc_last_in??
+
+{-
+\paragraph{Passes for forward dataflow problems}
+
+A forward dataflow pass has a similar structure, but the details are
+different. In particular, the output fact from a [[last]] node has a
+higher-order representation: it takes a function that mutates a
+[[uid]] to account for the new fact, then performs the necessary
+mutation on every successor of the last node. We therefore have two
+kinds of type parameter for outputs: output from a [[middle]] node
+is~[[outmid]], and output from a [[last]] node is~[[outlast]].
+-}
+
+data FComputation middle last input outmid outlast = FComp
+ { fc_name :: String
+ , fc_first_out :: input -> BlockId -> outmid
+ , fc_middle_out :: input -> middle -> outmid
+ , fc_last_outs :: input -> last -> outlast
+ , fc_exit_out :: input -> outmid
+ }
+
+-- | The notions of analysis, pass, and transformation are analogous to the
+-- backward case.
+
+newtype LastOutFacts a = LastOutFacts [(BlockId, a)]
+ -- ^ These are facts flowing out of a last node to the node's successors.
+ -- They are either to be set (if they pertain to the graph currently
+ -- under analysis) or propagated out of a sub-analysis
+
+type FAnalysis m l a = FComputation m l a a (LastOutFacts a)
+type FTransformation m l a = FComputation m l a (Maybe (UniqSM (Graph m l)))
+ (Maybe (UniqSM (Graph m l)))
+type FFunctionalTransformation m l a =
+ FComputation m l a (Maybe (Graph m l))
+ (Maybe (Graph m l))
+ -- ToDo: consider replacing UniqSM (Graph l m) with (AGraph m l)
+
+type FPass m l a = FComputation m l a
+ (OptimizationFuel -> DFM a (Answer m l a))
+ (OptimizationFuel -> DFM a (Answer m l (LastOutFacts a)))
+
+type FUnlimitedPass m l a = FComputation m l a
+ (DFM a (Answer m l a))
+ (DFM a (Answer m l (LastOutFacts a)))
+
+{-
+\paragraph{Composing passes}
+
+Both forward and backward engines share a handful of functions for
+composing analyses, transformations, and passes.
+
+We can make an analysis pass, or we can
+combine a related analysis and transformation into a full pass.
+-}
+
+null_b_ft :: BFunctionalTransformation m l a
+null_f_ft :: FFunctionalTransformation m l a
+
+anal_b :: BAnalysis m l a -> BPass m l a
+a_t_b :: BAnalysis m l a -> BTransformation m l a -> BPass m l a
+a_ft_b :: BAnalysis m l a -> BFunctionalTransformation m l a -> BPass m l a
+a_ft_b_unlimited
+ :: BAnalysis m l a -> BFunctionalTransformation m l a -> BPass m l a
+ -- ^ Ignores transaction limits. Could produce a BUnlimitedPass statically,
+ -- but that would cost too much code in the implementation for a
+ -- static distinction that is not worth so much.
+ignore_transactions_b :: BUnlimitedPass m l a -> BPass m l a
+
+
+
+anal_f :: FAnalysis m l a -> FPass m l a
+a_t_f :: FAnalysis m l a -> FTransformation m l a -> FPass m l a
+
+
+{-
+\paragraph {Running the dataflow engine}
+
+Every function for running analyses has two forms, because for a
+forward analysis, we supply an entry fact, whereas for a backward
+analysis, we don't need to supply an exit fact (because a graph for a
+procedure doesn't have an exit node).
+It's possible we could make these things more regular.
+-}
+
+-- | The analysis functions set properties on unique IDs.
+
+run_b_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
+ BAnalysis m l a -> LGraph m l -> DFA a ()
+run_f_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
+ FAnalysis m l a -> a -> LGraph m l -> DFA a ()
+ -- ^ extra parameter is the entry fact
+
+-- | Rematerialize results of analysis for use elsewhere. Simply applies a
+-- fold function to every edge fact, in reverse postorder dfs. The facts
+-- should already have been computed into the monady by run_b_anal or b_rewrite.
+fold_edge_facts_b
+ :: LastNode l =>
+ (a -> b -> b) -> BAnalysis m l a -> LGraph m l -> (BlockId -> a) -> b -> b
+
+fold_edge_facts_with_nodes_b :: LastNode l
+ => (l -> a -> b -> b) -- ^ inedge to last node
+ -> (m -> a -> b -> b) -- ^ inedge to middle node
+ -> (BlockId -> a -> b -> b) -- ^ fact at label
+ -> BAnalysis m l a -- ^ backwards analysis
+ -> LGraph m l -- ^ graph
+ -> (BlockId -> a) -- ^ solution to bwd anal
+ -> b -> b
+
+
+-- | It can be useful to refine the results of an existing analysis,
+-- or for example to use the outcome of a forward analsysis in a
+-- backward analysis. These functions can also be used to compute a
+-- fixed point iteratively starting from somewhere other than bottom
+-- (as in the reachability analysis done for proc points).
+
+class (Outputable m, Outputable l, LastNode l, Outputable (LGraph m l)) => DebugNodes m l
+
+refine_f_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
+ FAnalysis m l a -> LGraph m l -> DFA a () -> DFA a ()
+
+refine_b_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
+ BAnalysis m l a -> LGraph m l -> DFA a () -> DFA a ()
+
+b_rewrite :: (DebugNodes m l, Outputable a) =>
+ BPass m l a -> LGraph m l -> DFM a (LGraph m l)
+f_rewrite :: (DebugNodes m l, LastNode l, Outputable m, Outputable a) =>
+ FPass m l a -> a -> LGraph m l -> DFM a (LGraph m l)
+ -- ^ extra parameter is the entry fact
+
+b_shallow_rewrite
+ :: (DebugNodes m l, Outputable a)
+ => BAnalysis m l a -> BFunctionalTransformation m l a ->
+ Graph m l -> DFM a (Graph m l)
+
+b_shallow_rewrite = error "unimp"
+
+f_shallow_rewrite
+ :: (DebugNodes m l, Outputable a)
+ => FAnalysis m l a -> FFunctionalTransformation m l a ->
+ a -> Graph m l -> DFM a (Graph m l)
+
+
+-- | If the solution to a problem is already sitting in a monad, we
+-- should be able to take a short cut and just rewrite it in one pass.
+-- But not yet implemented.
+
+{-
+f_rewrite_solved :: (LastNode l, Outputable m, Outputable a) =>
+ FPass m l a -> DFM a () -> LGraph m l -> DFM a (LGraph m l)
+b_rewrite_solved :: (LastNode l, Outputable m, Outputable a) =>
+ BPass m l a -> DFM a () -> LGraph m l -> DFM a (LGraph m l)
+-}
+
+-- ===================== IMPLEMENTATION ======================--
+
+-- | Here's a function to run an action on blocks until we reach a fixed point.
+run :: (DataflowAnalysis anal, Monad (anal a), Outputable a, DebugNodes m l) =>
+ String -> String -> anal a () -> (b -> Block m l -> anal a b) ->
+ b -> [Block m l] -> anal a b
+run dir name set_entry do_block b blocks =
+ do { set_entry; show_blocks $ iterate (1::Int) }
+ where
+ -- N.B. Each iteration starts with the same transaction limit;
+ -- only the rewrites in the final iteration actually count
+ trace_block b block = my_trace "about to do" (text name <+> text "on" <+> ppr (blockId block)) $
+ do_block b block
+ iterate n =
+ do { markFactsUnchanged
+ ; b <- foldM trace_block b blocks
+ ; changed <- factsStatus
+ ; facts <- allFacts
+ ; let depth = 0 -- was nesting depth
+ ; ppIter depth n $
+ case changed of
+ NoChange -> unchanged depth $ return b
+ SomeChange ->
+ pprFacts depth n facts $
+ if n < 1000 then iterate (n+1)
+ else panic $ msg n
+ }
+ msg n = concat [name, " didn't converge in ", show n, " " , dir,
+ " iterations"]
+ my_nest depth sdoc = my_trace "" $ nest (3*depth) sdoc
+ ppIter depth n = my_nest depth (empty $$ text "*************** iteration" <+> pp_i n)
+ pp_i n = int n <+> text "of" <+> text name <+> text "on" <+> graphId
+ unchanged depth = my_nest depth (text "facts are unchanged")
+
+ pprFacts depth n env =
+ my_nest depth (text "facts for iteration" <+> pp_i n <+> text "are:" $$
+ (nest 2 $ vcat $ map pprFact $ ufmToList env))
+ pprFact (id, a) = hang (ppr id <> colon) 4 (ppr a)
+ graphId = case blocks of { Block id _ : _ -> ppr id ; [] -> text "<empty>" }
+ show_blocks = my_trace "Blocks:" (vcat (map pprBlock blocks))
+ pprBlock (Block id t) = nest 2 (pprFact (id, t))
+
+{-
+\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
+ setFact id $ head_in h (last_in comp env l) -- 'in' fact for the block
+ 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 (oneLessFuel fuel) 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 (oneLessFuel fuel) 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 (oneLessFuel fuel) 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 (oneLessFuel fuel) 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 (oneLessFuel fuel) 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 (oneLessFuel fuel) 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 <- fuelRemaining
+ ; bot <- botFact
+ ; (fuel', _, gc) <- solve_and_rewrite_b comp fuel g bot
+ ; fuelDecrement (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 | canRewriteWithFuel fuel
+ -> 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) = last_outs setEdgeFacts 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 :: (DataflowAnalysis df, Outputable a) => (LastOutFacts a -> df a ()) -> FComputation m l i a (LastOutFacts a) -> i -> G.ZLast l -> df a ()
+last_outs _do_last_outs comp i (G.LastExit) = setExitFact (fc_exit_out comp i)
+last_outs do_last_outs comp i (G.LastOther l) = do_last_outs $ fc_last_outs comp i l
+
+last_rewrite :: FComputation m l i a a -> i -> G.ZLast l -> a
+last_rewrite comp i (G.LastExit) = fc_exit_out comp i
+last_rewrite comp i (G.LastOther l) = fc_last_outs comp i l
+
+
+-- | 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 { fuel <- general_forward fuel in_fact g
+ ; a <- getExitFact
+ ; outs <- lastOutFacts
+ ; return (fuel, a, outs) }
+ where
+ -- general_forward :: FPass m l a -> OptimizationFuel -> a -> G.LGraph m l -> DFM a OptimizationFuel
+ general_forward 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 (oneLessFuel fuel) g in'
+ set_or_save last_outs
+ set_tail_facts fuel out t
+ set_tail_facts fuel in' (G.ZLast LastExit) =
+ fc_exit_out comp in' fuel >>= \x -> case x of
+ Dataflow a -> do { setExitFact a; return fuel }
+ Rewrite _g -> error "rewriting exit node not implemented"
+ set_tail_facts fuel in' (G.ZLast (G.LastOther l)) =
+ fc_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 (oneLessFuel fuel) 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 (oneLessFuel fuel) 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
+ (fuel, g) <- forward_rewrite comp fuel graph in_fact
+ exit_fact <- getExitFact --- XXX should drop this; it's in the monad
+ return (fuel, exit_fact, g)
+
+f_shallow_rewrite anal ftx in_fact g =
+ do { fuel <- fuelRemaining
+ ; solve_shallow_graph_f (return ()) anal ftx in_fact g fuel
+ ; id <- freshBlockId "temporary entry id"
+ ; (blocks, fuel') <-
+ forward_rewrite_gen don't_rewrite anal ftx (ZFirst id) in_fact g fuel
+ ; fuelDecrement (fc_name ftx) fuel fuel'
+ ; return (remove_entry_label (LGraph id blocks))
+ }
+ where don't_rewrite finish g fuel = finish >>= \b -> return (b, g, fuel)
+
+
+shallow_tail_solve_f
+ :: (DebugNodes m l, Outputable a)
+ => DFM a b -- final action and result after solving this tail
+ -> FAnalysis m l a -> FFunctionalTransformation m l a
+ -> (BlockId -> Bool) -- local blocks
+ -> a -> ZTail m l -> OptimizationFuel -> DFM a (b, OptimizationFuel)
+shallow_tail_solve_f finish anal ftx is_local in' (G.ZTail m t) fuel =
+ my_trace "Solving middle node" (ppr m) $
+ case maybeRewriteWithFuel fuel $ fc_middle_out ftx in' m of
+ Just g -> do out <- subAnalysis' $ liftAnal $
+ anal_f_general getExitFact anal in' g
+ shallow_tail_solve_f finish anal ftx is_local out t (oneLessFuel fuel)
+ Nothing -> shallow_tail_solve_f finish anal ftx is_local
+ (fc_middle_out anal in' m) t fuel
+shallow_tail_solve_f finish anal ftx is_local in' (G.ZLast (G.LastOther l)) fuel =
+ case maybeRewriteWithFuel fuel $ fc_last_outs ftx in' l of
+ Just g -> do { last_outs <-
+ subAnalysis' $ liftAnal $ anal_f_general lastOutFacts anal in' g
+ ; set_or_save last_outs
+ ; b <- finish
+ ; return (b, oneLessFuel fuel) }
+ Nothing -> do { set_or_save (fc_last_outs anal in' l)
+ ; b <- finish
+ ; return (b, fuel) }
+ where set_or_save = mk_set_or_save is_local
+shallow_tail_solve_f finish anal ftx _is_local in' (G.ZLast LastExit) fuel =
+ case maybeRewriteWithFuel fuel $ fc_exit_out ftx in' of
+ Just g -> do { a <-
+ subAnalysis' $ liftAnal $ anal_f_general getExitFact anal in' g
+ ; setExitFact a
+ ; b <- finish
+ ; return (b, oneLessFuel fuel) }
+ Nothing -> do { setExitFact $ fc_exit_out anal in'
+ ; b <- finish
+ ; return (b, fuel) }
+
+anal_f_general :: (DebugNodes m l, Outputable a)
+ => DFA a b -> FAnalysis m l a -> a -> Graph m l -> DFA a b
+anal_f_general finish anal in_fact (Graph entry blockenv) =
+ general_forward in_fact
+ where
+ is_local id = isJust $ lookupBlockEnv blockenv id
+ set_or_save = mk_set_or_save is_local
+ anal_tail = gen_tail_anal_f set_or_save anal
+ blocks = G.postorder_dfs_from blockenv entry
+ general_forward in_fact =
+ do { let setup = anal_tail in_fact entry -- sufficient to do once
+ ; let set_successor_facts () (Block id tail) =
+ do { idfact <- getFact id
+ ; anal_tail (fc_first_out anal idfact id) tail }
+ ; run "forward" (fc_name anal) setup set_successor_facts () blocks
+ ; finish
+ }
+
+gen_tail_anal_f :: (Outputable a) =>
+ (LastOutFacts a -> DFA a ()) -> FAnalysis m l a -> a -> ZTail m l -> DFA a ()
+gen_tail_anal_f do_last_outs anal a tail = propagate a tail
+ where propagate a (ZTail m t) = propagate (fc_middle_out anal a m) t
+ propagate a (ZLast LastExit) = setExitFact (fc_exit_out anal a)
+ propagate a (ZLast (LastOther l)) = do_last_outs $ fc_last_outs anal a l
+
+
+solve_shallow_graph_f ::
+ (DebugNodes m l, Outputable a) =>
+ DFM a b ->
+ FAnalysis m l a -> FFunctionalTransformation m l a -> a -> G.Graph m l
+ -> OptimizationFuel -> DFM a (b, OptimizationFuel)
+solve_shallow_graph_f finish anal ftx in_fact (Graph entry blockenv) fuel =
+ do { fuel <- general_forward in_fact fuel
+ ; b <- finish
+ ; return (b, fuel) }
+ where
+ is_local id = isJust $ lookupBlockEnv blockenv id
+ set_or_save = mk_set_or_save is_local
+ solve_tail = shallow_tail_solve_f lastOutFacts anal ftx is_local
+ blocks = G.postorder_dfs_from blockenv entry
+ name = concat [fc_name anal, " and ", fc_name ftx]
+ general_forward in_fact fuel =
+ do { (last_outs, fuel) <- solve_tail in_fact entry fuel
+ ; set_or_save last_outs
+ ; let set_successor_facts fuel (Block id tail) =
+ do { idfact <- getFact id
+ ; (last_outs, fuel) <-
+ case maybeRewriteWithFuel fuel $ fc_first_out ftx idfact id of
+ Nothing -> solve_tail idfact tail fuel
+ Just g ->
+ do outfact <-
+ subAnalysis' $ liftAnal $
+ anal_f_general getExitFact anal idfact g
+ solve_tail outfact tail (oneLessFuel fuel)
+ ; set_or_save last_outs
+ ; return fuel }
+ ; run "forward" name (return ()) set_successor_facts fuel blocks }
+
+mk_set_or_save :: (DataflowAnalysis df, Monad (df a), Outputable a) =>
+ (BlockId -> Bool) -> LastOutFacts a -> df a ()
+mk_set_or_save is_local (LastOutFacts l) = mapM_ set_or_save_one l
+ where set_or_save_one (id, a) =
+ if is_local id then setFact id a else addLastOutFact (id, a)
+
+lastOutFacts :: (DataflowAnalysis m, Monad (m f)) => m f (LastOutFacts f)
+lastOutFacts = bareLastOutFacts >>= return . LastOutFacts
+
+
+fwd_rew_tail_gen :: (DebugNodes m l, Outputable a) =>
+ (forall b . DFM a b -> Graph m l -> OptimizationFuel -> DFM a (b, Graph m l, OptimizationFuel)) ->
+ FAnalysis m l a -> FFunctionalTransformation m l a -> ZHead m -> a -> ZTail m l
+ -> BlockEnv (Block m l)
+ -> OptimizationFuel -> DFM a (BlockEnv (Block m l), OptimizationFuel)
+fwd_rew_tail_gen recursive_rewrite anal ftx head in_fact tail rewritten fuel =
+ propagate head in_fact tail rewritten fuel
+ where
+ propagate h in' (G.ZTail m t) rewritten fuel =
+ my_trace "Rewriting middle node" (ppr m) $
+ case maybeRewriteWithFuel fuel $ fc_middle_out ftx in' m of
+ Nothing -> propagate (G.ZHead h m) (fc_middle_out anal in' m) t rewritten fuel
+ Just g -> do markGraphRewritten
+ (a, g, fuel) <- recursive_rewrite getExitFact g fuel
+ let (blocks, h') = G.splice_head' h g
+ propagate h' a t (blocks `plusUFM` rewritten) fuel
+ propagate h in' (G.ZLast l) rewritten fuel =
+ case maybeRewriteWithFuel fuel $ last_rewrite ftx in' l of
+ Nothing -> -- can throw away facts because this is the rewriting phase
+ return (insertBlock (zipht h (G.ZLast l)) rewritten, fuel)
+ Just g -> do markGraphRewritten
+ ((), g, fuel) <- recursive_rewrite (return ()) g fuel
+ let g' = G.splice_head_only' h g
+ return (G.lg_blocks g' `plusUFM` rewritten, fuel)
+
+forward_rewrite_gen ::
+ (DebugNodes m l, Outputable a) =>
+ (forall b . DFM a b -> Graph m l -> OptimizationFuel -> DFM a (b, Graph m l, OptimizationFuel)) ->
+ FAnalysis m l a -> FFunctionalTransformation m l a -> ZHead m -> a -> Graph m l
+ -> OptimizationFuel -> DFM a (BlockEnv (Block m l), OptimizationFuel)
+forward_rewrite_gen recursive_rewrite anal ftx head a (Graph entry blockenv) fuel =
+ do (rewritten, fuel) <- rewrite_tail head a entry emptyBlockEnv fuel
+ rewrite_blocks (G.postorder_dfs_from blockenv entry) rewritten fuel
+ where
+ -- need to build in some checking for consistency of facts
+ rewrite_tail = fwd_rew_tail_gen recursive_rewrite anal ftx
+ rewrite_blocks [] rewritten fuel = return (rewritten, fuel)
+ rewrite_blocks (G.Block id t : bs) rewritten fuel =
+ do id_fact <- getFact id
+ case maybeRewriteWithFuel fuel $ fc_first_out ftx id_fact id of
+ Nothing -> do { (rewritten, fuel) <-
+ rewrite_tail (ZFirst id) id_fact t rewritten fuel
+ ; rewrite_blocks bs rewritten fuel }
+ Just g -> do { (outfact, g, fuel) <- recursive_rewrite getExitFact g fuel
+ ; let (blocks, h) = splice_head' (ZFirst id) g
+ ; (rewritten, fuel) <-
+ rewrite_tail h outfact t (blocks `plusUFM` rewritten) fuel
+ ; rewrite_blocks bs rewritten fuel }
+
+
+
+
+
+
+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 (oneLessFuel fuel) 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 (oneLessFuel fuel) g in'
+ let (blocks, h') = G.splice_head' h g
+ propagate fuel h' a t (blocks `plusUFM` rewritten) bs
+ propagate fuel h in' t@(G.ZLast G.LastExit) rewritten bs =
+ do fc_exit_out comp in' fuel >>= \x -> case x of
+ Dataflow a ->
+ do setExitFact a
+ let b = G.zipht h t
+ rewrite_blocks fuel (G.insertBlock b rewritten) bs
+ Rewrite g ->
+ do markGraphRewritten
+ (fuel, _, g) <- solve_and_rewrite_f_graph comp (oneLessFuel fuel) g in'
+ let g' = G.splice_head_only' h g
+ rewrite_blocks fuel (G.lg_blocks g' `plusUFM` rewritten) bs
+ propagate fuel h in' t@(G.ZLast (G.LastOther l)) rewritten bs =
+ do fc_last_outs comp in' l fuel >>= \x -> case x of
+ Dataflow outs ->
+ do set_or_save outs
+ let b = G.zipht h t
+ rewrite_blocks fuel (G.insertBlock b rewritten) bs
+ Rewrite g ->
+ do markGraphRewritten
+ (fuel, _, g) <- solve_and_rewrite_f_graph comp (oneLessFuel fuel) 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 <- fuelRemaining
+ ; (fuel', _, gc) <- solve_and_rewrite_f comp fuel g entry_fact
+ ; fuelDecrement (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_out = wrap1 $ fc_exit_out 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_out in' fuel = undefined
+ answer fuel (fc_exit_out tx in') (fc_exit_out 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_out = exit_out }
+
+
+f4sep :: [SDoc] -> SDoc
+f4sep [] = fsep []
+f4sep (d:ds) = fsep (d : map (nest 4) ds)
+
+subAnalysis' :: (Monad (m f), DataflowAnalysis m, Outputable f) =>
+ m f a -> m f a
+subAnalysis' m =
+ do { a <- subAnalysis $
+ do { a <- m; facts <- allFacts
+ ; my_trace "after sub-analysis facts are" (pprFacts facts) $
+ return a }
+ ; facts <- allFacts
+ ; my_trace "in parent analysis facts are" (pprFacts facts) $
+ return a }
+ where pprFacts env = nest 2 $ vcat $ map pprFact $ ufmToList env
+ pprFact (id, a) = hang (ppr id <> colon) 4 (ppr a)
+
+
+_unused :: FS.FastString
+_unused = undefined
+
+null_b_ft = BComp "do nothing" Nothing no2 no2 no2
+ where no2 _ _ = Nothing
+
+null_f_ft = FComp "do nothing" no2 no2 no2 (\_ -> Nothing)
+ where no2 _ _ = Nothing
+
projects / ghc-hetmet.git / blobdiff