-{-# OPTIONS -Wall -fno-warn-name-shadowing #-}
+{-# LANGUAGE ScopedTypeVariables #-}
module MkZipCfg
- ( AGraph, (<*>), emptyAGraph, withFreshLabel, withUnique
+ ( AGraph, (<*>), catAGraphs
+ , freshBlockId
+ , emptyAGraph, withFreshLabel, withUnique
, mkMiddle, mkMiddles, mkLast, mkZTail, mkBranch, mkLabel, mkIfThenElse, mkWhileDo
, outOfLine
, emptyGraph, graphOfMiddles, graphOfZTail
)
where
+import BlockId (BlockId(..), emptyBlockEnv)
import ZipCfg
import Outputable
import Unique
import UniqFM
import UniqSupply
+import Util
import Prelude hiding (zip, unzip, last)
+#include "HsVersions.h"
-------------------------------------------------------------------------
-- GENERIC ZIPPER-BASED CONTROL-FLOW GRAPH (CONSTRUCTOR VIEW) --
infixr 3 <*>
(<*>) :: AGraph m l -> AGraph m l -> AGraph m l
+catAGraphs :: [AGraph m l] -> AGraph m l
+
-- | A graph is built up by splicing together graphs each containing a
-- single node (where a label is considered a 'first' node. The empty
-- graph is a left and right unit for splicing. All of the AGraph
-- splicing operation <*>, are constant-time operations.
emptyAGraph :: AGraph m l
-mkLabel :: LastNode l =>
- BlockId -> AGraph m l -- graph contains the label
-mkMiddle :: m -> AGraph m l -- graph contains the node
+mkLabel :: (LastNode l) =>
+ BlockId -> Maybe Int -> AGraph m l -- graph contains the label
+mkMiddle :: m -> AGraph m l -- graph contains the node
mkLast :: (Outputable m, Outputable l, LastNode l) =>
l -> AGraph m l -- graph contains the node
-- below for convenience
-mkMiddles :: [m] -> AGraph m l
-mkZTail :: (Outputable m, Outputable l, LastNode l) => ZTail m l -> AGraph m l
-mkBranch :: (Outputable m, Outputable l, LastNode l) => BlockId -> AGraph m l
+mkMiddles :: [m] -> AGraph m l
+mkZTail :: (Outputable m, Outputable l, LastNode l) =>
+ ZTail m l -> AGraph m l
+mkBranch :: (Outputable m, Outputable l, LastNode l) =>
+ BlockId -> AGraph m l
-- | For the structured control-flow constructs, a condition is
-- represented as a function that takes as arguments the labels to
-- goto on truth or falsehood.
+--
+-- mkIfThenElse mk_cond then else
+-- = (mk_cond L1 L2) <*> L1: then <*> goto J
+-- <*> L2: else <*> goto J
+-- <*> J:
+--
+-- where L1, L2, J are fresh
mkIfThenElse :: (Outputable m, Outputable l, LastNode l)
=> (BlockId -> BlockId -> AGraph m l) -- branch condition
-- in the number of basic blocks. The conversion is also monadic
-- because it may require the allocation of fresh, unique labels.
-graphOfAGraph :: AGraph m l -> UniqSM (Graph m l)
-lgraphOfAGraph :: AGraph m l -> UniqSM (LGraph m l)
+graphOfAGraph :: AGraph m l -> UniqSM (Graph m l)
+lgraphOfAGraph :: Int -> AGraph m l -> UniqSM (LGraph m l)
-- ^ allocate a fresh label for the entry point
-labelAGraph :: BlockId -> AGraph m l -> UniqSM (LGraph m l)
+labelAGraph :: BlockId -> Int -> AGraph m l -> UniqSM (LGraph m l)
-- ^ use the given BlockId as the label of the entry point
AGraph f1 <*> AGraph f2 = AGraph f
where f g = f2 g >>= f1 -- note right associativity
+catAGraphs = foldr (<*>) emptyAGraph
+
emptyAGraph = AGraph return
graphOfAGraph (AGraph f) = f emptyGraph
emptyGraph = Graph (ZLast LastExit) emptyBlockEnv
-labelAGraph id g =
+labelAGraph id args g =
do Graph tail blocks <- graphOfAGraph g
- return $ LGraph id $ insertBlock (Block id tail) blocks
+ return $ LGraph id args $ insertBlock (Block id Nothing tail) blocks
-lgraphOfAGraph g = do id <- freshBlockId "graph entry"
- labelAGraph id g
+lgraphOfAGraph args g = do id <- freshBlockId "graph entry"
+ labelAGraph id args g
-------------------------------------
-- constructors
-mkLabel id = AGraph f
+mkLabel id args = AGraph f
where f (Graph tail blocks) =
return $ Graph (ZLast (mkBranchNode id))
- (insertBlock (Block id tail) blocks)
+ (insertBlock (Block id args tail) blocks)
mkBranch target = mkLast $ mkBranchNode target
f' g
withUnique ofU = AGraph f
- where f g = do u <- getUniqueUs
+ where f g = do u <- getUniqueM
let AGraph f' = ofU u
f' g
note_this_code_becomes_unreachable emptyEntrance
return $ Graph tail' (blocks `plusUFM` blocks')
-
mkIfThenElse cbranch tbranch fbranch =
withFreshLabel "end of if" $ \endif ->
withFreshLabel "start of then" $ \tid ->
withFreshLabel "start of else" $ \fid ->
cbranch tid fid <*>
- mkLabel tid <*> tbranch <*> mkBranch endif <*>
- mkLabel fid <*> fbranch <*> mkLabel endif
-
+ mkLabel tid Nothing <*> tbranch <*> mkBranch endif <*>
+ mkLabel fid Nothing <*> fbranch <*> mkLabel endif Nothing
mkWhileDo cbranch body =
withFreshLabel "loop test" $ \test ->
withFreshLabel "loop head" $ \head ->
withFreshLabel "end while" $ \endwhile ->
-- Forrest Baskett's while-loop layout
- mkBranch test <*> mkLabel head <*> body <*> mkLabel test
- <*> cbranch head endwhile <*> mkLabel endwhile
-
+ mkBranch test <*> mkLabel head Nothing <*> body <*> mkLabel test Nothing
+ <*> cbranch head endwhile <*> mkLabel endwhile Nothing
-- | Bleat if the insertion of a last node will create unreachable code
note_this_code_becomes_unreachable ::
(Monad m, LastNode l, Outputable middle, Outputable l) => ZTail middle l -> m ()
-#ifdef DEBUG
-note_this_code_becomes_unreachable = u
+note_this_code_becomes_unreachable = if debugIsOn then u else \_ -> return ()
where u (ZLast LastExit) = return ()
u (ZLast (LastOther l)) | isBranchNode l = return ()
-- Note [Branch follows branch]
u tail = fail ("unreachable code: " ++ showSDoc (ppr tail))
-#else
-note_this_code_becomes_unreachable = return ()
-#endif
{-
Note [Branch follows branch]
Emitting a Branch at this point is fine:
goto L1; L2: ...stuff...
-}
+
+
+-- | The string argument to 'freshBlockId' was originally helpful in debugging
+-- the Quick C-- compiler, so I have kept it here even though at present it is
+-- thrown away at this spot---there's no reason a BlockId couldn't one day carry
+-- a string.
+
+freshBlockId :: MonadUnique m => String -> m BlockId
+freshBlockId _s = getUniqueM >>= return . BlockId
+
projects / ghc-hetmet.git / blobdiff