-{-# 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(..)
, blockId, zip, unzip, last, goto_end, zipht, tailOfLast
, 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
, pprLgraph, pprGraph
- , entry -- exported for the convenience of ZipDataflow, at least for now
+ , entry -- exported for the convenience of ZipDataflow0, at least for now
{-
-- the following functions might one day be useful and can be found
#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)
'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
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
-- 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)
---- 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
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:
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.
-- 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
- in if (map blockId dfs1 == map blockId dfs2) then dfs2 else panic "inconsistent DFS"
+ let FGraph id eblock _ = entry g in
+ zip eblock : postorder_dfs_from_except blockenv eblock (unitUniqSet id)
-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
-
-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
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
-- | 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
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'
instance Uniquable BlockId where
getUnique (BlockId u) = u
+mkBlockId :: Unique -> BlockId
+mkBlockId uniq = BlockId uniq
+
instance Show BlockId where
show (BlockId u) = show u
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 $$ ppr t
-pprTail (ZLast LastExit) = text "<exit>"
-pprTail (ZLast (LastOther l)) = ppr l
+pprTail (ZLast l) = ppr l
+
+pprLast :: (Outputable l) => ZLast l -> SDoc
+pprLast LastExit = text "<exit>"
+pprLast (LastOther l) = ppr l
pprLgraph :: (Outputable m, Outputable l, LastNode l) => LGraph m l -> SDoc
pprLgraph g = text "{" $$ nest 2 (vcat $ map pprBlock blocks) $$ text "}"
where pprBlock (Block id tail) = ppr id <> colon $$ ppr tail
blocks = postorder_dfs_from blockenv tail
-_unused :: FS.FastString
-_unused = undefined
projects / ghc-hetmet.git / blobdiff