1 {-# LANGUAGE PatternGuards #-}
2 {-# OPTIONS -Wall -fno-warn-name-shadowing #-}
5 ( cmmToZgraph, cmmOfZgraph )
19 import qualified ZipCfg as G
21 cmmToZgraph :: GenCmm d h (ListGraph CmmStmt) -> UniqSM (GenCmm d h CmmGraph)
22 cmmOfZgraph :: GenCmm d h (CmmGraph) -> GenCmm d h (ListGraph CmmStmt)
24 cmmToZgraph = cmmMapGraphM toZgraph
25 cmmOfZgraph = cmmMapGraph ofZgraph
28 toZgraph :: String -> ListGraph CmmStmt -> UniqSM CmmGraph
29 toZgraph _ (ListGraph []) = lgraphOfAGraph emptyAGraph
30 toZgraph fun_name (ListGraph (BasicBlock id ss : other_blocks)) =
31 labelAGraph id $ mkStmts ss <*> foldr addBlock emptyAGraph other_blocks
32 where addBlock (BasicBlock id ss) g = mkLabel id <*> mkStmts ss <*> g
33 mkStmts (CmmNop : ss) = mkNop <*> mkStmts ss
34 mkStmts (CmmComment s : ss) = mkComment s <*> mkStmts ss
35 mkStmts (CmmAssign l r : ss) = mkAssign l r <*> mkStmts ss
36 mkStmts (CmmStore l r : ss) = mkStore l r <*> mkStmts ss
37 mkStmts (CmmCall f res args (CmmSafe srt) CmmMayReturn : ss) =
38 mkCall f res args srt <*> mkStmts ss
39 mkStmts (CmmCall f res args CmmUnsafe CmmMayReturn : ss) =
40 mkUnsafeCall f res args <*> mkStmts ss
41 mkStmts (CmmCondBranch e l : fbranch) =
42 mkIfThenElse (mkCbranch e) (mkBranch l) (mkStmts fbranch)
43 mkStmts (last : []) = mkLast last
44 mkStmts [] = bad "fell off end"
45 mkStmts (_ : _ : _) = bad "last node not at end"
46 bad msg = panic (msg {- ++ " in block " ++ showSDoc (ppr b) -}
47 ++ " in function " ++ fun_name)
48 mkLast (CmmCall f [] args _ CmmNeverReturns) = mkFinalCall f args
49 mkLast (CmmSwitch scrutinee table) = mkSwitch scrutinee table
50 mkLast (CmmJump tgt args) = mkJump tgt args
51 mkLast (CmmReturn ress) = mkReturn ress
52 mkLast (CmmBranch tgt) = mkBranch tgt
53 mkLast (CmmCall _f (_:_) _args _ CmmNeverReturns) =
54 panic "Call never returns but has results?!"
55 mkLast _ = panic "fell off end of block"
57 ofZgraph :: CmmGraph -> ListGraph CmmStmt
58 ofZgraph g = ListGraph $ swallow blocks
59 where blocks = G.postorder_dfs g
60 -- | the next two functions are hooks on which to hang debugging info
61 extend_entry stmts = stmts
62 extend_block _id stmts = stmts
63 _extend_entry stmts = scomment showblocks : scomment cscomm : stmts
64 showblocks = "LGraph has " ++ show (length blocks) ++ " blocks:" ++
65 concat (map (\(G.Block id _) -> " " ++ show id) blocks)
66 cscomm = "Call successors are" ++
67 (concat $ map (\id -> " " ++ show id) $ uniqSetToList call_succs)
69 swallow (G.Block id t : rest) = tail id [] t rest
70 tail id prev' (G.ZTail m t) rest = tail id (mid m : prev') t rest
71 tail id prev' (G.ZLast G.LastExit) rest = exit id prev' rest
72 tail id prev' (G.ZLast (G.LastOther l))rest = last id prev' l rest
74 mid (MidComment s) = CmmComment s
75 mid (MidAssign l r) = CmmAssign l r
76 mid (MidStore l r) = CmmStore l r
77 mid (MidUnsafeCall f ress args) = CmmCall f ress args CmmUnsafe CmmMayReturn
78 mid m@(CopyOut {}) = pcomment (ppr m)
79 mid m@(CopyIn {}) = pcomment (ppr m <+> text "(proc point)")
80 pcomment p = scomment $ showSDoc p
82 | id == G.gr_entry g = BasicBlock id $ extend_entry (reverse prev')
83 | otherwise = BasicBlock id $ extend_block id (reverse prev')
85 let endblock stmt = block' id (stmt : prev') : swallow n in
87 LastBranch _ (_:_) -> panic "unrepresentable branch"
91 | tgt == id', unique_pred id'
92 -> tail id prev' t bs -- optimize out redundant labels
93 _ -> endblock (CmmBranch tgt)
94 LastCondBranch expr tid fid ->
97 | id' == fid, unique_pred id' ->
98 tail id (CmmCondBranch expr tid : prev') t bs
99 | id' == tid, unique_pred id',
100 Just e' <- maybeInvertCmmExpr expr ->
101 tail id (CmmCondBranch e' fid : prev') t bs
102 _ -> let instrs' = CmmBranch fid : CmmCondBranch expr tid : prev'
103 in block' id instrs' : swallow n
104 LastJump expr params -> endblock $ CmmJump expr params
105 LastReturn params -> endblock $ CmmReturn params
106 LastSwitch arg ids -> endblock $ CmmSwitch arg $ ids
107 LastCall tgt args Nothing ->
108 endblock $ CmmCall tgt [] args CmmUnsafe CmmNeverReturns
109 LastCall tgt args (Just k)
110 | G.Block id' (G.ZTail (CopyIn _ ress srt) t) : bs <- n,
111 id' == k, unique_pred k ->
112 let call = CmmCall tgt ress args (CmmSafe srt) CmmMayReturn
113 in tail id (call : prev') t bs
114 | G.Block id' t : bs <- n, id' == k, unique_pred k ->
115 let (ress, srt) = findCopyIn t
116 call = CmmCall tgt ress args (CmmSafe srt) CmmMayReturn
117 delayed = scomment "delayed CopyIn follows previous call"
118 in tail id (delayed : call : prev') t bs
119 | otherwise -> panic "unrepairable call"
120 findCopyIn (G.ZTail (CopyIn _ ress srt) _) = (ress, srt)
121 findCopyIn (G.ZTail _ t) = findCopyIn t
122 findCopyIn (G.ZLast _) = panic "missing CopyIn after call"
123 exit id prev' n = -- highly irregular (assertion violation?)
124 let endblock stmt = block' id (stmt : prev') : swallow n in
125 case n of [] -> endblock (scomment "procedure falls off end")
126 G.Block id' t : bs ->
127 if unique_pred id' then
128 tail id (scomment "went thru exit" : prev') t bs
130 endblock (CmmBranch id')
135 in case G.lookupBlockEnv preds id of
137 Just s -> if sizeUniqSet s == 1 then
138 G.extendBlockSet single id
140 in G.fold_blocks add G.emptyBlockSet g
141 unique_pred id = G.elemBlockSet id single_preds
144 case G.last (G.unzip b) of
145 G.LastOther (LastCall _ _ (Just id)) -> extendBlockSet succs id
147 in G.fold_blocks add emptyBlockSet g
148 _is_call_succ id = elemBlockSet id call_succs
150 scomment :: String -> CmmStmt
151 scomment s = CmmComment $ mkFastString s