X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fcmm%2FZipCfg.hs;h=67a4ecdde60e9cff77c33f6f7c76f1be6d86e864;hp=bf8d49f963d3ad0efa89fe789669f2fa1f712a7e;hb=ba60dc74fdb18fe655cfac605130cf6480116e47;hpb=b9bcf6e71abe0d861c99618ee5a7ae9e2c45d26c diff --git a/compiler/cmm/ZipCfg.hs b/compiler/cmm/ZipCfg.hs index bf8d49f..67a4ecd 100644 --- a/compiler/cmm/ZipCfg.hs +++ b/compiler/cmm/ZipCfg.hs @@ -1,8 +1,6 @@ -{-# LANGUAGE ScopedTypeVariables #-} module ZipCfg ( -- These data types and names are carefully thought out - BlockId(..), freshBlockId -- ToDo: BlockId should be abstract, - -- but it isn't yet + BlockId(..), mkBlockId -- ToDo: BlockId should be abstract, but it isn't yet , BlockEnv, emptyBlockEnv, lookupBlockEnv, extendBlockEnv, insertBlock, mkBlockEnv , BlockSet, emptyBlockSet, elemBlockSet, extendBlockSet, mkBlockSet , Graph(..), LGraph(..), FGraph(..) @@ -13,10 +11,9 @@ module ZipCfg -- Observers and transformers -- (open to renaming suggestions here) , blockId, zip, unzip, last, goto_end, zipht, tailOfLast - , remove_entry_label , splice_tail, splice_head, splice_head_only', splice_head' , of_block_list, to_block_list - , map_nodes + , map_blocks, map_nodes, mapM_blocks , postorder_dfs, postorder_dfs_from, postorder_dfs_from_except , fold_layout , fold_blocks @@ -24,6 +21,8 @@ module ZipCfg , pprLgraph, pprGraph + , entry -- exported for the convenience of ZipDataflow0, at least for now + {- -- the following functions might one day be useful and can be found -- either below or in ZipCfgExtras: @@ -38,12 +37,13 @@ where #include "HsVersions.h" +import CmmExpr ( UserOfLocalRegs(..) ) --for an instance + import Outputable hiding (empty) import Panic import Unique import UniqFM import UniqSet -import UniqSupply import Maybe import Prelude hiding (zip, unzip, last) @@ -77,7 +77,7 @@ the data constructor 'LastExit'. A graph may contain at most one 'LastExit' node, and a graph representing a full procedure should not contain any 'LastExit' nodes. 'LastExit' nodes are used only to splice graphs together, either during graph construction (see module 'MkZipCfg') -or during optimization (see module 'ZipDataflow'). +or during optimization (see module 'ZipDataflow0'). A graph is parameterized over the types of middle and last nodes. Each of these types will typically be instantiated with a subset of C-- statements @@ -99,13 +99,13 @@ increasing complexity, they are: There are three types because each type offers a slightly different invariant or cost model. - * The distinguished entry of a Graph has no label. Because labels must - be unique, acquiring one requires a monadic operation ('freshBlockId'). - The primary advantage of the Graph representation is that we can build - a small Graph purely functionally, without entering a monad. For - example, during optimization we can easily rewrite a single middle - node into a Graph containing a sequence of two middle nodes followed by - LastExit. + * The distinguished entry of a Graph has no label. Because labels must be + unique, acquiring one requires a supply of Unique labels (BlockId's). + The primary advantage of the Graph representation is that we can build a + small Graph purely functionally, without needing a fresh BlockId or + Unique. For example, during optimization we can easily rewrite a single + middle node into a Graph containing a sequence of two middle nodes + followed by LastExit. * In an LGraph, every basic block is labelled. The primary advantage of this representation is its simplicity: each basic block can be treated @@ -142,6 +142,14 @@ data ZLast l -- so we don't want to pollute the 'l' type parameter with it | LastOther l +--So that we don't have orphan instances, this goes here or in CmmExpr. +--At least UserOfLocalRegs (ZLast Last) is needed (Last defined elsewhere), +--but there's no need for non-Haskell98 instances for that. +instance UserOfLocalRegs a => UserOfLocalRegs (ZLast a) where + foldRegsUsed f z (LastOther l) = foldRegsUsed f z l + foldRegsUsed _f z LastExit = z + + data ZHead m = ZFirst BlockId | ZHead (ZHead m) m -- ZHead is a (reversed) sequence of middle nodes labeled by a BlockId data ZTail m l = ZLast (ZLast l) | ZTail m (ZTail m l) @@ -167,11 +175,6 @@ data FGraph m l = FGraph { fg_entry :: BlockId ---- Utility functions --- --- | 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 :: String -> UniqSM BlockId - blockId :: Block m l -> BlockId zip :: ZBlock m l -> Block m l unzip :: Block m l -> ZBlock m l @@ -273,11 +276,16 @@ fold_blocks :: (Block m l -> a -> a) -> a -> LGraph m l -> a map_nodes :: (BlockId -> BlockId) -> (m -> m') -> (l -> l') -> LGraph m l -> LGraph m' l' -- mapping includes the entry id! +map_blocks :: (Block m l -> Block m' l') -> LGraph m l -> LGraph m' l' +mapM_blocks :: Monad mm + => (Block m l -> mm (Block m' l')) -> LGraph m l -> mm (LGraph m' l') + -- | These translation functions are speculative. I hope eventually -- they will be used in the native-code back ends ---NR -translate :: (m -> UniqSM (LGraph m' l')) -> - (l -> UniqSM (LGraph m' l')) -> - (LGraph m l -> UniqSM (LGraph m' l')) +translate :: Monad tm => + (m -> tm (LGraph m' l')) -> + (l -> tm (LGraph m' l')) -> + (LGraph m l -> tm (LGraph m' l')) {- -- | It's possible that another form of translation would be more suitable: @@ -335,8 +343,6 @@ instance LastNode l => HavingSuccessors (ZTail m l) where blockId (Block id _) = id -freshBlockId _ = do { u <- getUniqueUs; return $ BlockId u } - -- | Convert block between forms. -- These functions are tail-recursive, so we can go as deep as we like -- without fear of stack overflow. @@ -435,40 +441,12 @@ single_exitg (Graph tail blocks) = foldUFM add (exit_count (lastTail tail)) bloc -- Better to geot [A,B,C,D] -postorder_dfs' :: LastNode l => LGraph m l -> [Block m l] -postorder_dfs' g@(LGraph _ blocks) = - let FGraph _ eblock _ = entry g - in vnode (zip eblock) (\acc _visited -> acc) [] emptyBlockSet - where - -- vnode :: - -- Block m l -> ([Block m l] -> BlockSet -> a) -> [Block m l] -> BlockSet -> a - vnode block@(Block id _) cont acc visited = - if elemBlockSet id visited then - cont acc visited - else - vchildren block (get_children block) cont acc (extendBlockSet visited id) - vchildren block bs cont acc visited = - let next children acc visited = - case children of [] -> cont (block : acc) visited - (b:bs) -> vnode b (next bs) acc visited - in next bs acc visited - get_children block = foldl add_id [] (succs block) - add_id rst id = case lookupBlockEnv blocks id of - Just b -> b : rst - Nothing -> rst - postorder_dfs g@(LGraph _ blockenv) = - let FGraph id eblock _ = entry g - dfs1 = zip eblock : - postorder_dfs_from_except blockenv eblock (unitUniqSet id) - dfs2 = postorder_dfs' g - in ASSERT (map blockId dfs1 == map blockId dfs2) dfs2 - -postorder_dfs_from - :: (HavingSuccessors b, LastNode l) => BlockEnv (Block m l) -> b -> [Block m l] -postorder_dfs_from blocks b = postorder_dfs_from_except blocks b emptyBlockSet + let FGraph id eblock _ = entry g in + zip eblock : postorder_dfs_from_except blockenv eblock (unitUniqSet id) -postorder_dfs_from_except :: forall b m l . (HavingSuccessors b, LastNode l) => BlockEnv (Block m l) -> b -> BlockSet -> [Block m l] +postorder_dfs_from_except :: (HavingSuccessors b, LastNode l) + => BlockEnv (Block m l) -> b -> BlockSet -> [Block m l] postorder_dfs_from_except blocks b visited = vchildren (get_children b) (\acc _visited -> acc) [] visited where @@ -490,6 +468,11 @@ postorder_dfs_from_except blocks b visited = Just b -> b : rst Nothing -> rst +postorder_dfs_from + :: (HavingSuccessors b, LastNode l) => BlockEnv (Block m l) -> b -> [Block m l] +postorder_dfs_from blocks b = postorder_dfs_from_except blocks b emptyBlockSet + + -- | Slightly more complicated than the usual fold because we want to tell block -- 'b1' what its inline successor is going to be, so that if 'b1' ends with @@ -506,12 +489,22 @@ fold_layout f z g@(LGraph eid _) = fold (postorder_dfs g) z -- | The rest of the traversals are straightforward +map_blocks f (LGraph eid blocks) = LGraph eid (mapUFM f blocks) + map_nodes idm middle last (LGraph eid blocks) = LGraph (idm eid) (mapUFM block blocks) where block (Block id t) = Block (idm id) (tail t) tail (ZTail m t) = ZTail (middle m) (tail t) tail (ZLast LastExit) = ZLast LastExit tail (ZLast (LastOther l)) = ZLast (LastOther (last l)) + +mapM_blocks f (LGraph eid blocks) = blocks' >>= return . LGraph eid + where blocks' = + foldUFM (\b mblocks -> do { blocks <- mblocks + ; b <- f b + ; return $ insertBlock b blocks }) + (return emptyBlockEnv) blocks + fold_blocks f z (LGraph _ blocks) = foldUFM f z blocks of_block_list e blocks = LGraph e $ foldr insertBlock emptyBlockEnv blocks @@ -622,12 +615,12 @@ translate txm txl (LGraph eid blocks) = return $ LGraph eid blocks' where -- txblock :: - -- Block m l -> UniqSM (BlockEnv (Block m' l')) -> UniqSM (BlockEnv (Block m' l')) + -- Block m l -> tm (BlockEnv (Block m' l')) -> tm (BlockEnv (Block m' l')) txblock (Block id t) expanded = do blocks' <- expanded txtail (ZFirst id) t blocks' -- txtail :: ZHead m' -> ZTail m l -> BlockEnv (Block m' l') -> - -- UniqSM (BlockEnv (Block m' l')) + -- tm (BlockEnv (Block m' l')) txtail h (ZTail m t) blocks' = do m' <- txm m let (g, h') = splice_head h m' @@ -656,6 +649,9 @@ newtype BlockId = BlockId Unique instance Uniquable BlockId where getUnique (BlockId u) = u +mkBlockId :: Unique -> BlockId +mkBlockId uniq = BlockId uniq + instance Show BlockId where show (BlockId u) = show u @@ -692,10 +688,19 @@ mkBlockSet = mkUniqSet instance (Outputable m, Outputable l) => Outputable (ZTail m l) where ppr = pprTail +instance (Outputable m, Outputable l, LastNode l) => Outputable (LGraph m l) where + ppr = pprLgraph + +instance (Outputable l) => Outputable (ZLast l) where + ppr = pprLast + pprTail :: (Outputable m, Outputable l) => ZTail m l -> SDoc pprTail (ZTail m t) = ppr m $$ ppr t -pprTail (ZLast LastExit) = text "" -pprTail (ZLast (LastOther l)) = ppr l +pprTail (ZLast l) = ppr l + +pprLast :: (Outputable l) => ZLast l -> SDoc +pprLast LastExit = text "" +pprLast (LastOther l) = ppr l pprLgraph :: (Outputable m, Outputable l, LastNode l) => LGraph m l -> SDoc pprLgraph g = text "{" $$ nest 2 (vcat $ map pprBlock blocks) $$ text "}" @@ -708,5 +713,3 @@ pprGraph (Graph tail blockenv) = where pprBlock (Block id tail) = ppr id <> colon $$ ppr tail blocks = postorder_dfs_from blockenv tail -_unused :: FS.FastString -_unused = undefined