-{-# OPTIONS -Wall -fno-warn-name-shadowing #-}
-{-# LANGUAGE ScopedTypeVariables, MultiParamTypeClasses #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
module ZipDataflow
( Answer(..)
, BComputation(..), BAnalysis, BTransformation, BFunctionalTransformation
import CmmTx
import DFMonad
-import ZipCfg hiding (freshBlockId) -- use version from DFMonad
+import ZipCfg
import qualified ZipCfg as G
import Outputable
import Control.Monad
import Maybe
+#include "HsVersions.h"
+
{-
\section{A very polymorphic infrastructure for dataflow problems}
{-
-\subsection {Descriptions of dataflow passes}
+============== Descriptions of dataflow passes} ================
-\paragraph{Passes for backward dataflow problems}
+------ Passes for backward dataflow problemsa
The computation of a fact is the basis of a dataflow pass.
-A~computation takes not one but two type parameters:
-\begin{itemize}
-\item
-Type parameter [['i]] is an input, from which it should be possible to
-derived a dataflow fact of interest.
-For example, [['i]] might be equal to a fact, or it might be a tuple
-of which one element is a fact.
-\item
-Type parameter [['o]] is an output, or possibly a function from
-[[txlimit]] to an output
-\end{itemize}
-Backward analyses compute [[in]] facts (facts on inedges).
-<<exported types for backward analyses>>=
+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
-- * 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))
-type BPass m l a = BComputation m l a (Txlimit -> 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}
type FTransformation m l a = FComputation m l a (Maybe (UniqSM (Graph m l)))
(Maybe (UniqSM (Graph m l)))
type FPass m l a = FComputation m l a
- (Txlimit -> DFM a (Answer m l a))
- (Txlimit -> DFM a (Answer m l (LastOutFacts 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))
-- | The analysis functions set properties on unique IDs.
-run_b_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable a) =>
+run_b_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
BAnalysis m l a -> LGraph m l -> DFA a ()
-run_f_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable 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
class (Outputable m, Outputable l, LastNode l, Outputable (LGraph m l)) => DebugNodes m l
-refine_f_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable a) =>
+refine_f_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
FAnalysis m l a -> LGraph m l -> DFA a () -> DFA a ()
-refine_b_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable 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) =>
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
+ 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
-- 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 (Txlimit -> DFM f (Answer m l o)) -> o ->
- BComputation m l i (Txlimit -> DFM f (Answer m l o))
+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 = \_txlim -> return $ Dataflow $ 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
-- Rewrite should always use exactly one of these monadic operations.
solve_graph_b ::
- forall m l a . (DebugNodes m l, Outputable a) =>
- BPass m l a -> Txlimit -> G.LGraph m l -> a -> DFM a (Txlimit, a)
-solve_graph_b comp txlim graph exit_fact =
- general_backward (comp_with_exit_b comp exit_fact) txlim graph
+ (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 -> Txlimit -> G.LGraph m l -> DFM a (Txlimit, a)
- general_backward comp txlim graph =
- let set_block_fact :: Txlimit -> G.Block m l -> DFM a Txlimit
- set_block_fact txlim b =
- do { (txlim, block_in) <-
+ -- 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 txlim >>= \x ->
+ factsEnv >>= \env -> last_in comp env l fuel >>= \x ->
case x of
- Dataflow a -> head_in txlim h a
+ Dataflow a -> head_in fuel h a
Rewrite g ->
do { bot <- botFact
- ; g <- lgraphOfGraph g
- ; (txlim, a) <- subAnalysis' $
- solve_graph_b comp (txlim-1) g bot
- ; head_in txlim h a }
+ ; (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 txlim
+ ; return fuel
}
- head_in txlim (G.ZHead h m) out =
- bc_middle_in comp out m txlim >>= \x -> case x of
- Dataflow a -> head_in txlim h a
+ 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 { g <- lgraphOfGraph g
- ; (txlim, a) <- subAnalysis' $ solve_graph_b comp (txlim-1) g out
- ; my_trace "Rewrote middle node" (f4sep [ppr m, text "to", ppr g]) $
- head_in txlim h a }
- head_in txlim (G.ZFirst id) out =
- bc_first_in comp out id txlim >>= \x -> case x of
- Dataflow a -> return (txlim, a)
- Rewrite g -> do { g <- lgraphOfGraph g
- ; subAnalysis' $ solve_graph_b comp (txlim-1) g out }
-
- in do { txlim <-
- run "backward" (bc_name comp) (return ()) set_block_fact txlim blocks
- ; a <- getFact (G.gr_entry graph)
+ 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 (txlim, 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 =
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
-}
solve_and_rewrite_b ::
- forall m l a. (DebugNodes m l, Outputable a) =>
- BPass m l a -> Txlimit -> LGraph m l -> a -> DFM a (Txlimit, a, LGraph m l)
+ (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 txlim graph exit_fact =
- do { (_, a) <- solve_graph_b comp txlim graph exit_fact -- pass 1
+
+solve_and_rewrite_b comp fuel graph exit_fact =
+ do { (_, a) <- solve_graph_b comp fuel graph exit_fact -- pass 1
; facts <- allFacts
- ; (txlim, g) <- -- pass 2
+ ; (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) txlim graph
+ 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 (txlim, a, g) }
+ 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.gr_entry graph
- backward_rewrite comp txlim graph =
- rewrite_blocks comp txlim emptyBlockEnv $ reverse (G.postorder_dfs graph)
- rewrite_blocks ::
- BPass m l a -> Txlimit ->
- BlockEnv (Block m l) -> [Block m l] -> DFM a (Txlimit,G.LGraph m l)
- rewrite_blocks _comp txlim rewritten [] = return (txlim, G.LGraph eid rewritten)
- rewrite_blocks comp txlim rewritten (b:bs) =
- let rewrite_next_block txlim =
+ 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 txlim >>= \x -> case x of
- Dataflow a -> propagate txlim h a (G.ZLast l) rewritten
- Rewrite g -> -- see Note [Rewriting labelled LGraphs]
- do { bot <- botFact
- ; g <- lgraphOfGraph g
- ; (txlim, a, g') <- solve_and_rewrite_b comp (txlim-1) g bot
- ; let G.Graph t new_blocks = G.remove_entry_label g'
- ; markGraphRewritten
- ; let rewritten' = plusUFM new_blocks rewritten
- ; -- continue at entry of g
- propagate txlim h a t rewritten'
+ 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 :: Txlimit -> G.ZHead m -> a -> G.ZTail m l ->
- BlockEnv (Block m l) -> DFM a (Txlimit, G.LGraph m l)
- propagate txlim (G.ZHead h m) out tail rewritten =
- bc_middle_in comp out m txlim >>= \x -> case x of
- Dataflow a -> propagate txlim h a (G.ZTail m tail) rewritten
+ -- 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 { g <- lgraphOfGraph g
- ; (txlim, a, g') <- solve_and_rewrite_b comp (txlim-1) g out
- ; markGraphRewritten
- ; let (t, g'') = G.splice_tail g' tail
- ; let rewritten' = plusUFM (G.gr_blocks g'') rewritten
- ; my_trace "Rewrote middle node" (f4sep [ppr m, text "to", ppr g]) $
- propagate txlim h a t rewritten' }
- propagate txlim h@(G.ZFirst id) out tail rewritten =
- bc_first_in comp out id txlim >>= \x -> case x of
+ 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 txlim (extendBlockEnv rewritten id b) bs }
- Rewrite fg ->
- do { g <- lgraphOfGraph fg
- ; (txlim, a, g') <- solve_and_rewrite_b comp (txlim-1) g out
- ; markGraphRewritten
- ; let (t, g'') = G.splice_tail g' tail
- ; let rewritten' = plusUFM (G.gr_blocks g'') rewritten
- ; my_trace "Rewrote label " (f4sep [ppr id, text "to", ppr g]) $
- propagate txlim h a t rewritten' }
- in rewrite_next_block txlim
+ ; 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 { txlim <- liftTx txRemaining
+ do { fuel <- liftTx txRemaining
; bot <- botFact
- ; (txlim', _, gc) <- solve_and_rewrite_b comp txlim g bot
- ; liftTx $ txDecrement (bc_name comp) txlim txlim'
+ ; (fuel', _, gc) <- solve_and_rewrite_b comp fuel g bot
+ ; liftTx $ txDecrement (bc_name comp) fuel fuel'
; return gc
}
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 txlim =
- let answer = f node txlim 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 txlim =
+ let wrapout f nodestring out node fuel =
fact "out" (nodestring node) out;
- wrap (f out) nodestring node txlim in
+ 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 =
, 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 _txlim = return $ Dataflow (f out node)
- wrap0 fact _txlim = return $ Dataflow fact
+ 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 _txlim = f out node
- wrap0 fact _txlim = fact
+ where wrap2 f out node _fuel = f out node
+ wrap0 fact _fuel = fact
-answer' :: (b -> DFM f (Graph m l)) -> Txlimit -> Maybe b -> a -> DFM f (Answer m l a)
-answer' lift txlim r a =
- case r of Just gc | txlim > 0 -> do { g <- lift gc; return $ Rewrite g }
+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)) -> Txlimit -> Maybe b -> a -> DFM f (Answer m l a)
-unlimited_answer' lift _txlim r a =
+ :: (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 :: (Txlimit -> Maybe b -> a -> DFM a (Answer m l 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 txlim =
- answer txlim (bc_last_in tx env l) (bc_last_in anal env l)
- exit_in txlim = answer txlim (bc_exit_in tx) (bc_exit_in anal)
- middle_in out m txlim =
- answer txlim (bc_middle_in tx out m) (bc_middle_in anal out m)
- first_in out f txlim =
- answer txlim (bc_first_in tx out f) (bc_first_in anal out f)
+ 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 }
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.gr_entry graph) entry_fact
+ 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
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.gr_entry graph then "<entry>" else show id
+ _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
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' _txlimit =
- return $ Dataflow $ LastOutFacts [(exit_fact_id, in')]
+ 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 ::
- forall m l a . (DebugNodes m l, Outputable a) =>
- FPass m l a -> Txlimit -> G.LGraph m l -> a ->
- DFM a (Txlimit, a, LastOutFacts a)
-solve_graph_f comp txlim g in_fact =
+ (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"
- ; txlim <- general_forward (comp_with_exit_f comp exit_fact_id) txlim in_fact g
+ ; 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 (txlim, a, LastOutFacts outs) }
+ ; return (fuel, a, LastOutFacts outs) }
where
- general_forward :: FPass m l a -> Txlimit -> a -> G.LGraph m l -> DFM a Txlimit
- general_forward comp txlim entry_fact graph =
+ -- 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.gr_blocks g) id
- set_or_save :: LastOutFacts a -> DFM a ()
+ 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.gr_entry graph) entry_fact
+ set_entry = setFact (G.lg_entry graph) entry_fact
- set_successor_facts txlim b =
- let set_tail_facts txlim in' (G.ZTail m t) =
+ 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 txlim >>= \ x -> case x of
- Dataflow a -> set_tail_facts txlim a t
+ fc_middle_out comp in' m fuel >>= \ x -> case x of
+ Dataflow a -> set_tail_facts fuel a t
Rewrite g ->
- do g <- lgraphOfGraph g
- (txlim, out, last_outs) <- subAnalysis' $
- solve_graph_f comp (txlim-1) g in'
+ do (fuel, out, last_outs) <-
+ subAnalysis' $ solve_graph_f_g comp (fuel-1) g in'
set_or_save last_outs
- set_tail_facts txlim out t
- set_tail_facts txlim in' (G.ZLast l) =
- last_outs comp in' l txlim >>= \x -> case x of
- Dataflow outs -> do { set_or_save outs; return txlim }
+ 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 g <- lgraphOfGraph g
- (txlim, _, last_outs) <- subAnalysis' $
- solve_graph_f comp (txlim-1) g in'
+ do (fuel, _, last_outs) <-
+ subAnalysis' $ solve_graph_f_g comp (fuel-1) g in'
set_or_save last_outs
- return txlim
+ return fuel
G.Block id t = b
in do idfact <- getFact id
- infact <- fc_first_out comp idfact id txlim
- case infact of Dataflow a -> set_tail_facts txlim a t
+ infact <- fc_first_out comp idfact id fuel
+ case infact of Dataflow a -> set_tail_facts fuel a t
Rewrite g ->
- do g <- lgraphOfGraph g
- (txlim, out, last_outs) <- subAnalysis' $
- solve_graph_f comp (txlim-1) g idfact
+ do (fuel, out, last_outs) <- subAnalysis' $
+ solve_graph_f_g comp (fuel-1) g idfact
set_or_save last_outs
- set_tail_facts txlim out t
- in run "forward" (fc_name comp) set_entry set_successor_facts txlim blocks
+ 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 }
{-
The tail is in final form; the head is still to be rewritten.
-}
solve_and_rewrite_f ::
- forall m l a . (DebugNodes m l, Outputable a) =>
- FPass m l a -> Txlimit -> LGraph m l -> a -> DFM a (Txlimit, a, LGraph m l)
-solve_and_rewrite_f comp txlim graph in_fact =
- do solve_graph_f comp txlim graph in_fact -- pass 1
+ (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"
- (txlim, g) <- forward_rewrite (comp_with_exit_f comp exit_id) txlim graph in_fact
+ (fuel, g) <- forward_rewrite (comp_with_exit_f comp exit_id) fuel graph in_fact
exit_fact <- getFact exit_id
- return (txlim, exit_fact, g)
+ 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 ::
- forall m l a . (DebugNodes m l, Outputable a) =>
- FPass m l a -> Txlimit -> G.LGraph m l -> a -> DFM a (Txlimit, G.LGraph m l)
-forward_rewrite comp txlim graph entry_fact =
+ (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 txlim emptyBlockEnv (G.postorder_dfs graph)
+ rewrite_blocks fuel emptyBlockEnv (G.postorder_dfs graph)
where
- eid = G.gr_entry graph
- is_local id = isJust $ lookupBlockEnv (G.gr_blocks graph) id
- set_or_save :: LastOutFacts a -> DFM a ()
+ 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 ::
- Txlimit -> BlockEnv (Block m l) -> [Block m l] -> DFM a (Txlimit, LGraph m l)
- rewrite_blocks txlim rewritten [] = return (txlim, G.LGraph eid rewritten)
- rewrite_blocks txlim rewritten (G.Block id t : bs) =
+ -- 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 txlim
+ first_out <- fc_first_out comp id_fact id fuel
case first_out of
- Dataflow a -> propagate txlim (G.ZFirst id) a t rewritten bs
- Rewrite fg -> do { markGraphRewritten
- ; rewrite_blocks (txlim-1) rewritten
- (G.postorder_dfs (labelGraph id fg) ++ bs) }
- propagate :: Txlimit -> G.ZHead m -> a -> G.ZTail m l -> BlockEnv (G.Block m l) ->
- [G.Block m l] -> DFM a (Txlimit, G.LGraph m l)
- propagate txlim h in' (G.ZTail m t) rewritten bs =
+ 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 txlim >>= \x -> case x of
- Dataflow a -> propagate txlim (G.ZHead h m) a t rewritten bs
+ 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 ->
- my_trace "Rewriting middle node...\n" empty $
- do g <- lgraphOfGraph g
- (txlim, a, g) <- solve_and_rewrite_f comp (txlim-1) g in'
- markGraphRewritten
- my_trace "Rewrite of middle node completed\n" empty $
- let (g', h') = G.splice_head h g in
- propagate txlim h' a t (plusUFM (G.gr_blocks g') rewritten) bs
- propagate txlim h in' (G.ZLast l) rewritten bs =
- do last_outs comp in' l txlim >>= \x -> case x of
+ 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 txlim (G.insertBlock b rewritten) bs
+ rewrite_blocks fuel (G.insertBlock b rewritten) bs
Rewrite g ->
- -- could test here that [[exits g = exits (G.Entry, G.ZLast l)]]
- {- if Debug.on "rewrite-last" then
- Printf.eprintf "ZLast node %s rewritten to:\n"
- (RS.rtl (G.last_instr l)); -}
- do g <- lgraphOfGraph g
- (txlim, _, g) <- solve_and_rewrite_f comp (txlim-1) g in'
- markGraphRewritten
- let g' = G.splice_head_only h g
- rewrite_blocks txlim (plusUFM (G.gr_blocks g') rewritten) bs
+ 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 { txlim <- liftTx txRemaining
- ; (txlim', _, gc) <- solve_and_rewrite_f comp txlim g entry_fact
- ; liftTx $ txDecrement (fc_name comp) txlim txlim'
+ do { fuel <- liftTx txRemaining
+ ; (fuel', _, gc) <- solve_and_rewrite_f comp fuel g entry_fact
+ ; liftTx $ txDecrement (fc_name comp) fuel fuel'
; return gc
}
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 txlim =
+ let wrap f nodestring wrap_answer in' node fuel =
fact "in " (nodestring node) in';
- wrap_answer (nodestring node) (f in' node txlim)
+ wrap_answer (nodestring node) (f in' node fuel)
and wrap_fact n answer =
let () = match answer with
| Dataflow a -> fact "out" n a
, fc_last_outs = wrap2 $ fc_last_outs comp
, fc_exit_outs = wrap1 $ fc_exit_outs comp
}
- where wrap2 f out node _txlim = return $ Dataflow (f out node)
- wrap1 f fact _txlim = return $ Dataflow (f fact)
+ 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 txlim =
- answer txlim (fc_first_out tx in' id) (fc_first_out anal in' id)
- middle_out in' m txlim =
- answer txlim (fc_middle_out tx in' m) (fc_middle_out anal in' m)
- last_outs in' l txlim =
- answer txlim (fc_last_outs tx in' l) (fc_last_outs anal in' l)
- exit_outs in' txlim = undefined
- answer txlim (fc_exit_outs tx in') (fc_exit_outs anal in')
+ 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 }
-{- 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.
-
-(A good place to start changing things would be to figure out what is
-the analogue of postorder_dfs for Graphs, and to figure out what
-higher-order functions would do for dealing with the resulting
-sequences of *things*.)
--}
-
f4sep :: [SDoc] -> SDoc
f4sep [] = fsep []
f4sep (d:ds) = fsep (d : map (nest 4) ds)
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
projects / ghc-hetmet.git / blobdiff