tock-mirror/transformations/ImplicitMobility.hs

96 lines
3.4 KiB
Haskell

{-
Tock: a compiler for parallel languages
Copyright (C) 2007 University of Kent
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program. If not, see <http://www.gnu.org/licenses/>.
-}
module ImplicitMobility where
import Control.Monad
import Control.Monad.Trans
import Data.Graph.Inductive
import Data.Graph.Inductive.Query.DFS
import qualified Data.Map as Map
import Data.Maybe
import qualified Data.Set as Set
import qualified AST as A
import Errors
import FlowAlgorithms
import FlowGraph
import FlowUtils
import Metadata
import Pass
import UsageCheckUtils
import Utils
calculateUsedAgainAfter :: Monad m => FlowGraph m UsageLabel -> Node -> Either String (Map.Map Node
(Set.Set Var))
calculateUsedAgainAfter g startNode
= flowAlgorithm funcs (udfs [startNode] g) (startNode, Set.empty)
where
funcs :: GraphFuncs Node EdgeLabel (Set.Set Var)
funcs = GF
{ nodeFunc = iterate
-- Backwards data flow:
, nodesToProcess = lsuc g
, nodesToReAdd = lpre g
, defVal = Set.empty
, userErrLabel = ("for node at: " ++) . show . fmap getNodeMeta . lab g
}
iterate :: (Node, EdgeLabel) -> Set.Set Var -> Maybe (Set.Set Var) -> Set.Set
Var
iterate node _ mvs = case lab g (fst node) of
Just ul -> let nvars = writtenVars $ nodeVars $ getNodeData ul in
maybe nvars (Set.union nvars) mvs
Nothing -> error "Node label not found in calculateUsedAgainAfter"
--TODO rememember to take note of declarations/scope, otherwise this:
-- seqeach (..) {int:x; ... x = 3;}
-- will look like x is used again on the next loop iteration
-- TODO look at the types, too!
printMoveCopyDecisions :: Monad m => FlowGraph m UsageLabel -> Node -> PassM ()
printMoveCopyDecisions gr n
= case calculateUsedAgainAfter gr n of
Left err -> dieP (getNodeMeta $ fromJust $ lab gr n) err
Right mvs -> mapMapWithKeyM f mvs >> return ()
where
f :: Node -> (Set.Set Var) -> PassM (Set.Set Var)
f n vs = case liftM (readVars . nodeVars . getNodeData) $ lab gr n of
Nothing -> dieP emptyMeta "Did not find label in pmcd"
Just rv -> (mapM_ g $ Set.toList rv) >> return vs
where
g :: Var -> PassM ()
g v | Set.member v vs = liftIO . putStrLn $ show (findMeta v) ++ " COPY"
| otherwise = liftIO . putStrLn $ show (findMeta v) ++ " MOVE"
implicitMobility :: A.AST -> PassM A.AST
implicitMobility t
= do g' <- buildFlowGraph labelFunctions t
:: PassM (Either String (FlowGraph' PassM UsageLabel (), [Node],
[Node]))
case g' of
Left err -> dieP emptyMeta $ "Error building flow graph: " ++ err
Right (g, roots, terms) ->
-- We go from the terminator nodes, because we are performing backward
-- data-flow analysis
(liftIO $ putStrLn $ makeFlowGraphInstr g) >>
mapM_ (printMoveCopyDecisions g) terms
return t