-module CmmCPS (cmmCPS) where
+module CmmCPS (
+ -- | Converts C-- with full proceedures and parameters
+ -- to a CPS transformed C-- with the stack made manifest.
+ cmmCPS
+) where
#include "HsVersions.h"
import CmmLint
import PprCmm
-import Dataflow -- (fixedpoint, cmmLivenessComment, cmmLiveness, CmmLive)
+import Dataflow
+import CmmLive
+import CmmBrokenBlock
+import CmmProcPoint
+import CmmCallConv
import MachOp
import ForeignCall
import Monad
import IO
+import Data.List
+
+-----------------------------------------------------------------------------
+-- |Top level driver for the CPS pass
+-----------------------------------------------------------------------------
+cmmCPS :: DynFlags -- ^ Dynamic flags: -dcmm-lint -ddump-cps-cmm
+ -> [Cmm] -- ^ Input C-- with Proceedures
+ -> IO [Cmm] -- ^ Output CPS transformed C--
+cmmCPS dflags abstractC = do
+ when (dopt Opt_DoCmmLinting dflags) $
+ do showPass dflags "CmmLint"
+ case firstJust $ map cmmLint abstractC of
+ Just err -> do printDump err
+ ghcExit dflags 1
+ Nothing -> return ()
+ showPass dflags "CPS"
---------------------------------------------------------------------------------
--- Monad for the CPSer
--- Contains:
--- * State for the uniqSupply
-
-data CPSState = CPSState { cps_uniqs :: UniqSupply }
+ -- TODO: more lint checking
+ -- check for use of branches to non-existant blocks
+ -- check for use of Sp, SpLim, R1, R2, etc.
-data CPS a = CPS { runCPS :: CPSState -> (CPSState, a) }
+ uniqSupply <- mkSplitUniqSupply 'p'
+ let supplies = listSplitUniqSupply uniqSupply
+ let doCpsProc s (Cmm c) =
+ Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c
+ let continuationC = zipWith doCpsProc supplies abstractC
-instance Monad CPS where
- return a = CPS $ \s -> (s, a)
- (CPS m) >>= f = CPS $ \s ->
- let (s', m') = m s
- in runCPS (f m') s'
+ dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC)
---------------------------------------------------------------------------------
--- Utility functions
+ -- TODO: add option to dump Cmm to file
-getState = CPS $ \s -> (s, s)
-putState s = CPS $ \_ -> (s, ())
+ return continuationC
-newLabelCPS = do
- state <- getState
- let (us1, us2) = splitUniqSupply (cps_uniqs state)
- putState $ state { cps_uniqs = us1 }
- return $ BlockId (uniqFromSupply us2)
+-----------------------------------------------------------------------------
+-- |CPS a single CmmTop (proceedure)
+-- Only 'CmmProc' are transformed 'CmmData' will be left alone.
+-----------------------------------------------------------------------------
-mapMCmmTop :: (Monad m) => (CmmTop -> m [CmmTop]) -> Cmm -> m Cmm
-mapMCmmTop f (Cmm xs) = liftM Cmm $ liftM concat $ mapM f xs
+cpsProc :: UniqSupply
+ -> CmmTop -- ^Input proceedure
+ -> [CmmTop] -- ^Output proceedure and continuations
+cpsProc uniqSupply x@(CmmData _ _) = [x]
+cpsProc uniqSupply x@(CmmProc info_table ident params blocks) = cps_procs
+ where
+ uniqes :: [[Unique]]
+ uniqes = map uniqsFromSupply $ listSplitUniqSupply uniqSupply
+
+ -- Break the block at each function call.
+ -- The part after the function call will have to become a continuation.
+ broken_blocks :: [BrokenBlock]
+ broken_blocks =
+ concat $ zipWith3 breakBlock uniqes blocks
+ (FunctionEntry ident params:repeat ControlEntry)
+
+ -- Calculate live variables for each broken block.
+ --
+ -- Nothing can be live on entry to the first block
+ -- so we could take the tail, but for now we wont
+ -- to help future proof the code.
+ live :: BlockEntryLiveness
+ live = cmmLiveness $ map cmmBlockFromBrokenBlock broken_blocks
+
+ -- Calculate which blocks must be made into full fledged procedures.
+ proc_points :: UniqSet BlockId
+ proc_points = calculateProcPoints broken_blocks
+
+ -- Construct a map so we can lookup a broken block by its 'BlockId'.
+ block_env :: BlockEnv BrokenBlock
+ block_env = blocksToBlockEnv broken_blocks
+
+ -- Group the blocks into continuations based on the set of proc-points.
+ continuations :: [Continuation]
+ continuations = map (gatherBlocksIntoContinuation proc_points block_env)
+ (uniqSetToList proc_points)
+
+ -- Select the stack format on entry to each continuation.
+ --
+ -- This is an association list instead of a UniqFM because
+ -- CLabel's don't have a 'Uniqueable' instance.
+ formats :: [(CLabel, StackFormat)]
+ formats = selectStackFormat live continuations
+
+ -- Do the actual CPS transform.
+ cps_procs :: [CmmTop]
+ cps_procs = map (continuationToProc formats) continuations
--------------------------------------------------------------------------------
-- and heap memory (not sure if that's usefull at all though, but it may
-- be worth exploring the design space).
-data BrokenBlock
- = BrokenBlock
- BlockId -- Like a CmmBasicBlock
- BlockEntryInfo -- How this block can be entered
- [CmmStmt] -- Like a CmmBasicBlock (but without
- -- the last statement)
- BlockExitInfo -- How the block can be left
-
-data BlockEntryInfo
- = FunctionEntry -- Beginning of function
-
- | ContinuationEntry -- Return point of a call
- CmmFormals {- return values -}
- -- TODO | ProcPointEntry {- no return values, but some live might end up as params -}
-
- | ControlEntry -- A label in the input
-
-data BlockExitInfo
- = ControlExit [BlockId] -- blocks branched to conditionally
- BlockId -- next block (must be a ControlEntry)
-
- | ReturnExit [BlockId] -- blocks branched to conditionally
- CmmActuals -- return values
-
- | TailCallExit [BlockId] -- blocks branched to conditionally
- CmmExpr -- the function to call
- CmmActuals -- arguments to call
-
- | CallExit [BlockId] -- blocks branched to conditionally
- BlockId -- next block after call (must be a ContinuationEntry)
- CmmCallTarget -- the function to call
- CmmFormals -- results from call (redundant with ContinuationEntry)
- CmmActuals -- arguments to call
- (Maybe [GlobalReg]) -- registers that must be saved (TODO)
- -- TODO: | ProcPointExit (needed?)
-
-data CPSBlockInfo
- = ControlBlock -- Consider whether a proc-point might want arguments on stack
- | ContinuationBlock [(CmmReg,MachHint)] {- params -}
- | EntryBlock
-
---type StackFormat = [Maybe LocalReg] -- TODO: consider params as part of format
+continuationLabel (Continuation _ _ l _ _) = l
+data Continuation =
+ Continuation
+ Bool -- True => Function entry, False => Continuation/return point
+ [CmmStatic] -- Info table, may be empty
+ CLabel -- Used to generate both info & entry labels
+ CmmFormals -- Argument locals live on entry (C-- procedure params)
+ [BrokenBlock] -- Code, may be empty. The first block is
+ -- the entry point. The order is otherwise initially
+ -- unimportant, but at some point the code gen will
+ -- fix the order.
+
+ -- the BlockId of the first block does not give rise
+ -- to a label. To jump to the first block in a Proc,
+ -- use the appropriate CLabel.
+
+-- Describes the layout of a stack frame for a continuation
data StackFormat
= StackFormat
- BlockId {- block that is the start of the continuation. may or may not be the current block -}
- WordOff {- total frame size -}
- [(CmmReg, WordOff)] {- local reg offsets from stack top -}
+ (Maybe CLabel) -- The label occupying the top slot
+ WordOff -- Total frame size in words
+ [(CmmReg, WordOff)] -- local reg offsets from stack top
-- A block can be a continuation of a call
-- A block can be a continuation of another block (w/ or w/o joins)
-- A block can be an entry to a function
+-----------------------------------------------------------------------------
+
+collectNonProcPointTargets ::
+ UniqSet BlockId -> BlockEnv BrokenBlock
+ -> UniqSet BlockId -> BlockId -> UniqSet BlockId
+collectNonProcPointTargets proc_points blocks current_targets block =
+ if sizeUniqSet current_targets == sizeUniqSet new_targets
+ then current_targets
+ else foldl (collectNonProcPointTargets proc_points blocks) new_targets targets
+ where
+ block' = lookupWithDefaultUFM blocks (panic "TODO") block
+ targets =
+ -- Note the subtlety that since the extra branch after a call
+ -- will always be to a block that is a proc-point,
+ -- this subtraction will always remove that case
+ uniqSetToList $ (mkUniqSet $ brokenBlockTargets block') `minusUniqSet` proc_points
+ -- TODO: remove redundant uniqSetToList
+ new_targets = current_targets `unionUniqSets` (mkUniqSet targets)
+
+-- TODO: insert proc point code here
+-- * Branches and switches to proc points may cause new blocks to be created
+-- (or proc points could leave behind phantom blocks that just jump to them)
+-- * Proc points might get some live variables passed as arguments
+
+gatherBlocksIntoContinuation ::
+ UniqSet BlockId -> BlockEnv BrokenBlock
+ -> BlockId -> Continuation
+gatherBlocksIntoContinuation proc_points blocks start =
+ Continuation is_entry info_table clabel params body
+ where
+ children = (collectNonProcPointTargets proc_points blocks (unitUniqSet start) start) `delOneFromUniqSet` start
+ start_block = lookupWithDefaultUFM blocks (panic "TODO") start
+ children_blocks = map (lookupWithDefaultUFM blocks (panic "TODO")) (uniqSetToList children)
+ body = start_block : children_blocks
+ info_table = [] -- TODO
+ start_block_entry = brokenBlockEntry start_block
+ is_entry = case start_block_entry of
+ FunctionEntry _ _ -> True
+ _ -> False
+ clabel = case start_block_entry of
+ FunctionEntry label _ -> label
+ _ -> mkReturnPtLabel $ getUnique start
+ params = case start_block_entry of
+ FunctionEntry _ args -> args
+ ContinuationEntry args -> args
+ ControlEntry -> [] -- TODO: it's a proc-point, we could pass lives in parameter registers
+
--------------------------------------------------------------------------------
-- For now just select the continuation orders in the order they are in the set with no gaps
--- TODO: select a format that keeps blocks that can jump to each other the same
--- Assumed that jumps, calls
-selectStackFormat :: UniqFM {-BlockId-} CmmFormals -> UniqFM {-BlockId-} CmmLive -> UniqFM {-BlockId-} [(CPSBlockInfo, CmmBasicBlock)] -> UniqFM {-BlockId-} StackFormat
-selectStackFormat = undefined
-{-
-selectStackFormat param live blocks = fixedpoint
-listToUFM $ map live_to_format $ ufmToList live
+
+selectStackFormat :: BlockEnv CmmLive -> [Continuation] -> [(CLabel, StackFormat)]
+selectStackFormat live continuations =
+ map (\c -> (continuationLabel c, selectStackFormat' c)) continuations
where
- live_to_format (unique, live) = (unique, format) where
- format = foldl extend_format
- (StackFormat (BlockId unique) retAddrSizeW [])
- (uniqSetToList live)
+ selectStackFormat' (Continuation True info_table label formals blocks) =
+ StackFormat (Just label) 0 []
+ selectStackFormat' (Continuation False info_table label formals blocks) =
+ -- TODO: assumes the first block is the entry block
+ let ident = brokenBlockId $ head blocks -- TODO: CLabel isn't a uniquable, but we need a better way than this
+ in live_to_format label formals $ lookupWithDefaultUFM live unknown_block ident
+
+ live_to_format :: CLabel -> CmmFormals -> CmmLive -> StackFormat
+ live_to_format label formals live =
+ foldl extend_format
+ (StackFormat (Just label) retAddrSizeW [])
+ (uniqSetToList (live `minusUniqSet` mkUniqSet (cmmFormalsToLiveLocals formals)))
+
extend_format :: StackFormat -> LocalReg -> StackFormat
- extend_format (StackFormat block size offsets) reg =
- StackFormat block (slot_size reg + size) ((CmmLocal reg, size) : offsets)
--}
-
-selectStackFormat2 :: UniqFM {-BlockId-} CmmLive -> [BrokenBlock] -> UniqFM {-BlockId-} StackFormat
-selectStackFormat2 live blocks = fixedpoint dependants update (map brokenBlockId blocks) emptyUFM where
- blocks_ufm = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks
- dependants ident =
- case lookupWithDefaultUFM blocks_ufm (panic "TODO") ident of
- (BrokenBlock _ _ _ (ControlExit exits next)) -> next:exits
- (BrokenBlock _ _ _ (ReturnExit exits _)) -> exits
- (BrokenBlock _ _ _ (TailCallExit exits _ _)) -> exits
- (BrokenBlock _ _ _ (CallExit exits _ _ _ _ _)) -> exits
- update ident cause formats =
- let BrokenBlock _ entry _ _ = lookupWithDefaultUFM blocks_ufm (panic "unknown BlockId in selectStackFormat:live") ident in
- case cause of
- -- Propagate only to blocks entered by branches (not function entry blocks or continuation entry blocks)
- Just cause_name ->
- let cause_format = lookupWithDefaultUFM formats (panic "update signaled for block not in format") cause_name
- in case entry of
- ControlEntry -> Just $ addToUFM formats ident cause_format
- FunctionEntry -> Nothing
- ContinuationEntry _ -> Nothing
- -- Do initial calculates for function blocks
- Nothing ->
- case entry of
- ControlEntry -> Nothing
- FunctionEntry -> Just $ addToUFM formats ident $ StackFormat ident 0 []
- ContinuationEntry _ -> Just $ addToUFM formats ident $ live_to_format ident $ lookupWithDefaultUFM live (panic "TODO") ident
- live_to_format label live =
- foldl extend_format
- (StackFormat label retAddrSizeW [])
- (uniqSetToList live)
- extend_format :: StackFormat -> LocalReg -> StackFormat
- extend_format (StackFormat block size offsets) reg =
- StackFormat block (slot_size reg + size) ((CmmLocal reg, size) : offsets)
-
-slot_size reg = ((machRepByteWidth (localRegRep reg) - 1) `div` wORD_SIZE) + 1
-
-transformReturn :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} StackFormat -> CmmBasicBlock -> CmmBasicBlock
-transformReturn block_infos formats (BasicBlock ident stmts) =
- -- NOTE: assumes that return/jump can *only* appear at end of block
- case last stmts of
- CmmReturn arguments ->
- BasicBlock ident $
- (init stmts) ++
- exit_function curr_format (CmmLoad (CmmReg spReg) wordRep) arguments
- CmmJump target arguments ->
- BasicBlock ident $
- (init stmts) ++
- exit_function curr_format target arguments
- _ -> BasicBlock ident stmts
- where
- curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident
-
-destructContinuation :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} StackFormat -> CmmBasicBlock -> CmmBasicBlock
-destructContinuation block_infos formats (BasicBlock ident stmts) =
- case info of
- ControlBlock -> BasicBlock ident stmts
- ContinuationBlock _ -> BasicBlock ident (unpack_continuation curr_format ++ stmts)
- where
- info = lookupWithDefaultUFM block_infos (panic $ "info: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident
- curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident
-
-constructContinuation2 :: UniqFM {-BlockId-} StackFormat -> BrokenBlock -> CmmBasicBlock
-constructContinuation2 formats (BrokenBlock ident entry stmts exit) =
- BasicBlock ident (prefix++stmts++postfix)
+ extend_format (StackFormat label size offsets) reg =
+ StackFormat label (slot_size reg + size) ((CmmLocal reg, size) : offsets)
+
+ slot_size :: LocalReg -> Int
+ slot_size reg = ((machRepByteWidth (localRegRep reg) - 1) `div` wORD_SIZE) + 1
+
+ unknown_block = panic "unknown BlockId in selectStackFormat"
+
+continuationToProc :: [(CLabel, StackFormat)] -> Continuation -> CmmTop
+continuationToProc formats (Continuation is_entry info label formals blocks) =
+ CmmProc info label formals (map (continuationToProc' label formats) blocks)
where
- curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident
- prefix = case entry of
- ControlEntry -> []
- FunctionEntry -> []
- ContinuationEntry formals -> unpack_continuation curr_format
- postfix = case exit of
- ControlExit _ next -> [CmmBranch next]
- ReturnExit _ arguments -> exit_function curr_format (CmmLoad (CmmReg spReg) wordRep) arguments
- TailCallExit _ target arguments -> exit_function curr_format target arguments
- -- TODO: do something about global saves
- CallExit _ next (CmmForeignCall target CmmCallConv) results arguments saves ->
- let cont_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique next)) next
- in pack_continuation curr_format cont_format ++
- [CmmJump target arguments]
- CallExit _ next _ results arguments saves -> panic "unimplemented CmmCall"
-
-constructContinuation :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} StackFormat -> CmmBasicBlock -> CmmBasicBlock
-constructContinuation block_infos formats (BasicBlock ident stmts) =
- case last $ init stmts of
- -- TODO: global_saves
- --CmmCall (CmmForeignCall target CmmCallConv) results arguments (Just []) -> --TODO: handle globals
- CmmCall (CmmForeignCall target CmmCallConv) results arguments _ ->
- BasicBlock ident $
- init (init stmts) ++
- pack_continuation curr_format cont_format ++
- [CmmJump target arguments]
- CmmCall target results arguments _ -> panic "unimplemented CmmCall"
- -- TODO: branches for proc-points
- -- _ -> BasicBlock ident $ (init stmts) ++ build_block_branch
- _ -> BasicBlock ident stmts
- where
- info = lookupWithDefaultUFM block_infos (panic $ "info: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) next_block
- cont_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) next_block
- curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) ident
- next_block = case last stmts of
- CmmBranch next -> next
- -- TODO: blocks with jump at end
- -- TODO: blocks with return at end
- _ -> panic $ "basic block without a branch at the end (unimplemented) " ++ (showSDoc $ ppr $ stmts)
- next_block_as_proc_expr = CmmLit $ CmmLabel $ mkReturnPtLabel $ getUnique next_block
- block_needs_call = True -- TODO: use a table (i.e. proc-point)
- build_block_branch =
- if block_needs_call
- then [CmmJump next_block_as_proc_expr [] {- TODO: pass live -}] {- NOTE: a block can never be both a continuation and a controll block -}
- else [CmmBranch next_block]
+ continuationToProc' :: CLabel -> [(CLabel, StackFormat)] -> BrokenBlock
+ -> CmmBasicBlock
+ continuationToProc' curr_ident formats (BrokenBlock ident entry stmts _ exit) =
+ BasicBlock ident (prefix++stmts++postfix)
+ where
+ curr_format = maybe unknown_block id $ lookup curr_ident formats
+ unknown_block = panic "unknown BlockId in continuationToProc"
+ prefix = case entry of
+ ControlEntry -> []
+ FunctionEntry _ _ -> []
+ ContinuationEntry formals ->
+ unpack_continuation curr_format
+ postfix = case exit of
+ FinalBranch next -> [CmmBranch next]
+ FinalSwitch expr targets -> [CmmSwitch expr targets]
+ FinalReturn arguments ->
+ exit_function curr_format
+ (CmmLoad (CmmReg spReg) wordRep)
+ arguments
+ FinalJump target arguments ->
+ exit_function curr_format target arguments
+ FinalCall next (CmmForeignCall target CmmCallConv)
+ results arguments ->
+ pack_continuation curr_format cont_format ++
+ [CmmJump target arguments]
+ where
+ cont_format = maybe unknown_block id $
+ lookup (mkReturnPtLabel $ getUnique next) formats
+ FinalCall next _ results arguments -> panic "unimplemented CmmCall"
--------------------------------------------------------------------------------
-- Functions that generate CmmStmt sequences
exit_function :: StackFormat -> CmmExpr -> CmmActuals -> [CmmStmt]
exit_function (StackFormat curr_id curr_frame_size curr_offsets) target arguments
= adjust_spReg ++ jump where
- adjust_spReg = [
- CmmAssign spReg
- (CmmRegOff spReg (curr_frame_size*wORD_SIZE))]
+ adjust_spReg =
+ if curr_frame_size == 0
+ then []
+ else [CmmAssign spReg
+ (CmmRegOff spReg (curr_frame_size*wORD_SIZE))]
jump = [CmmJump target arguments]
enter_function :: WordOff -> [CmmStmt]
(CmmMachOp (MO_U_Lt $ cmmRegRep spReg)
[CmmRegOff spReg max_frame_size, CmmReg spLimReg])
gc_block]
- gc_block = undefined -- TODO: get stack and heap checks to go to same
+ gc_block = panic "gc_check not implemented" -- TODO: get stack and heap checks to go to same
-- TODO: fix branches to proc point (we have to insert a new block to marshel the continuation)
pack_continuation :: StackFormat -> StackFormat -> [CmmStmt]
spReg (wORD_SIZE*(curr_frame_size - cont_frame_size + offset)))
(CmmReg reg)
| (reg, offset) <- cont_offsets]
- set_stack_header = -- TODO: only set when needed
- [CmmStore (CmmRegOff spReg (wORD_SIZE*(curr_frame_size - cont_frame_size))) continuation_function]
- continuation_function = CmmLit $ CmmLabel $ mkReturnPtLabel $ getUnique cont_id
+ needs_header =
+ case (curr_id, cont_id) of
+ (Just x, Just y) -> x /= y
+ _ -> isJust cont_id
+ set_stack_header =
+ if not needs_header
+ then []
+ else [CmmStore (CmmRegOff spReg (wORD_SIZE*(curr_frame_size - cont_frame_size))) continuation_function]
+ continuation_function = CmmLit $ CmmLabel $ fromJust cont_id
adjust_spReg =
if curr_frame_size == cont_frame_size
then []
(CmmLoad (CmmRegOff spReg (wORD_SIZE*offset)) (cmmRegRep reg))
| (reg, offset) <- curr_offsets]
--- TODO: TBD when to adjust the stack
-
-cpsProc :: CmmTop -> CPS [CmmTop]
-cpsProc x@(CmmData _ _) = return [x]
-cpsProc x@(CmmProc info_table ident params blocks) = do
-
- broken_blocks <- liftM concat $ mapM breakBlock blocks
- broken_blocks2 <- liftM concat (zipWithM breakBlock2 blocks (FunctionEntry:repeat ControlEntry))
- -- broken_blocks :: [BrokenBlock]
-
- let live = cmmLiveness (map snd broken_blocks)
- let live2 :: BlockEntryLiveness
- live2 = cmmLiveness2 broken_blocks2
-
- let blocks_with_live = map (cmmLivenessComment live . snd) broken_blocks
-
- let formats = selectStackFormat (panic "params to selectStackFormat" {-TODO-}) live (undefined)
- let formats2 :: BlockEnv StackFormat -- Stack format on entry
- formats2 = selectStackFormat2 live2 broken_blocks2
-
- let block_infos = listToUFM $ map (\(info, block) -> (blockId block, info)) broken_blocks
- --let blocks_with_live' = map (constructContinuation block_infos formats) blocks_with_live
- --let blocks_with_live'' = map (destructContinuation block_infos formats) blocks_with_live'
- --let blocks_with_live''' = map (transformReturn block_infos formats) blocks_with_live''
-
- return $ [CmmProc info_table ident params $ map (constructContinuation2 formats2) broken_blocks2]
-{-
- return $ [CmmProc info_table ident params $
- map (constructContinuation block_infos formats .
- destructContinuation block_infos formats .
- transformReturn block_infos formats)
- blocks_with_live]
--}
-
---------------------------------------------------------------------------------
--- Takes a basic block and returns a list of basic blocks that
--- each have at most 1 CmmCall in them which must occur at the end.
--- Also returns with each basic block, the variables that will
--- be arguments to the continuation of the block once the call (if any) returns.
-
-cmmBlockifyCalls :: [CmmBasicBlock] -> CPS [(CPSBlockInfo, CmmBasicBlock)]
-cmmBlockifyCalls blocks = liftM concat $ mapM breakBlock blocks
-
--- [(CmmReg,MachHint)] is the results from the previous block that are expected as parameters
---breakBlock :: CmmBasicBlock -> CPS [(Maybe BlockId, CmmBasicBlock)]
-breakBlock :: CmmBasicBlock -> CPS [(CPSBlockInfo, CmmBasicBlock)]
-breakBlock (BasicBlock ident stmts) = breakBlock' ident ControlBlock [] stmts
-
-breakBlock' current_id block_info accum_stmts [] =
- return [(block_info, BasicBlock current_id accum_stmts)]
--- TODO: notice a call just before a branch, jump, call, etc.
-breakBlock' current_id block_info accum_stmts (stmt@(CmmCall _ results _ _):stmts) = do
- new_id <- newLabelCPS
- let new_block = (block_info, BasicBlock current_id (accum_stmts ++ [stmt, CmmBranch new_id]))
- rest <- breakBlock' new_id (ContinuationBlock results) [] stmts
- return $ (new_block:rest)
-breakBlock' current_id arguments accum_stmts (stmt:stmts) =
- breakBlock' current_id arguments (accum_stmts ++ [stmt]) stmts
-
-breakBlock2 (BasicBlock ident stmts) entry = breakBlock2' ident entry [] [] stmts
-
-breakBlock2' current_id block_info exits accum_stmts [] =
- panic "block doesn't end in jump, goto or return"
-breakBlock2' current_id entry exits accum_stmts [CmmJump target arguments] =
- return [BrokenBlock current_id entry accum_stmts (TailCallExit exits target arguments)]
-breakBlock2' current_id entry exits accum_stmts [CmmReturn arguments] =
- return [BrokenBlock current_id entry accum_stmts (ReturnExit exits arguments)]
-breakBlock2' current_id entry exits accum_stmts [CmmBranch target] =
- return [BrokenBlock current_id entry accum_stmts (ControlExit exits target)]
-breakBlock2' _ _ _ _ (CmmJump _ _:_) = panic "jump in middle of block"
-breakBlock2' _ _ _ _ (CmmReturn _:_) = panic "return in middle of block"
-breakBlock2' _ _ _ _ (CmmBranch _:_) = panic "branch in middle of block"
-breakBlock2' _ _ _ _ (CmmSwitch _ _:_) = panic "switch in block not implemented"
-breakBlock2' current_id entry exits accum_stmts (CmmCall target results arguments saves:stmts) = do
- new_id <- newLabelCPS
- rest <- breakBlock2' new_id (ContinuationEntry results) [] [] stmts
- return $ BrokenBlock current_id entry accum_stmts (CallExit exits new_id target results arguments saves) : rest
-breakBlock2' current_id entry exits accum_stmts (s@(CmmCondBranch test target):stmts) =
- breakBlock2' current_id entry (target:exits) (accum_stmts++[s]) stmts
-breakBlock2' current_id entry exits accum_stmts (s:stmts) =
- breakBlock2' current_id entry exits (accum_stmts++[s]) stmts
-
-brokenBlockTargets (BrokenBlock _ _ _ (TailCallExit exits _ _)) = exits
-brokenBlockTargets (BrokenBlock _ _ _ (ReturnExit exits _)) = exits
-brokenBlockTargets (BrokenBlock _ _ _ (ControlExit exits target)) = target:exits
-brokenBlockTargets (BrokenBlock _ _ _ (CallExit exits next _ _ _ _)) = next:exits
-
-brokenBlockId (BrokenBlock ident _ _ _) = ident
-
-cmmBrokenBlockSources ::
- [BrokenBlock] -> UniqFM {-BlockId-} (UniqSet BlockId)
-cmmBrokenBlockSources blocks = foldr aux emptyUFM blocks where
- aux block sourcesUFM =
- foldr add_source_edges sourcesUFM targets where
- add_source_edges t ufm =
- addToUFM_Acc (flip addOneToUniqSet) unitUniqSet ufm t ident
- targets = brokenBlockTargets block
- ident = brokenBlockId block
-
-cmmBrokenBlockNames :: [BrokenBlock] -> UniqFM {-BlockId-} BrokenBlock
-cmmBrokenBlockNames blocks = listToUFM $ map block_name blocks where
- block_name b = (brokenBlockId b, b)
-
-cmmBrokenBlockDependants :: UniqFM {-BlockId-} (UniqSet BlockId) -> BlockId -> [BlockId]
-cmmBrokenBlockDependants sources ident =
- uniqSetToList $ lookupWithDefaultUFM sources emptyUniqSet ident
-
-cmmBrokenBlockLive :: UniqFM {-BlockId-} CmmLive -> BrokenBlock -> CmmLive
-cmmBrokenBlockLive other_live (BrokenBlock _ _ stmts exit) =
- foldr ((.) . (cmmStmtLive other_live)) id stmts live_at_end
- where
- live_at_end =
- case exit of
- ControlExit _ _ -> emptyUniqSet
- ReturnExit _ actuals -> foldr ((.) . cmmExprLive) id (map fst actuals) emptyUniqSet
- TailCallExit _ target actuals ->
- cmmExprLive target $ foldr ((.) . cmmExprLive) id (map fst actuals) $ emptyUniqSet
- CallExit _ _ target _ actuals live ->
- target_liveness $
- foldr ((.) . cmmExprLive) id (map fst actuals) $
- emptyUniqSet
- where
- only_local_regs [] = []
- only_local_regs ((CmmGlobal _,_):args) = only_local_regs args
- only_local_regs ((CmmLocal r,_):args) = r:only_local_regs args
- target_liveness =
- case target of
- (CmmForeignCall target _) -> cmmExprLive target
- (CmmPrim _) -> id
-
-
-cmmBrokenBlockUpdate ::
- UniqFM {-BlockId-} BrokenBlock
- -> BlockId
- -> Maybe BlockId
- -> UniqFM {-BlockId-} CmmLive
- -> Maybe (UniqFM {-BlockId-} CmmLive)
-cmmBrokenBlockUpdate blocks node _ state =
- let old_live = lookupWithDefaultUFM state (panic "unknown block id during liveness analysis") node
- block = lookupWithDefaultUFM blocks (panic "unknown block id during liveness analysis") node
- new_live = cmmBrokenBlockLive state block
- in if (sizeUniqSet old_live) == (sizeUniqSet new_live)
- then Nothing
- else Just $ addToUFM state node new_live
-
-
-cmmLiveness2 :: [BrokenBlock] -> UniqFM {-BlockId-} CmmLive
-cmmLiveness2 blocks =
- fixedpoint (cmmBrokenBlockDependants sources) (cmmBrokenBlockUpdate blocks')
- (map brokenBlockId blocks) (listToUFM [(brokenBlockId b, emptyUniqSet) | b <- blocks]) where
- sources = cmmBrokenBlockSources blocks
- blocks' = cmmBrokenBlockNames blocks
-
---------------------------------------------------------------------------------
-cmmCPS :: DynFlags
- -> [Cmm] -- C-- with Proceedures
- -> IO [Cmm] -- Output: CPS transformed C--
-
-cmmCPS dflags abstractC = do
- when (dopt Opt_DoCmmLinting dflags) $
- do showPass dflags "CmmLint"
- case firstJust $ map cmmLint abstractC of
- Just err -> do printDump err
- ghcExit dflags 1
- Nothing -> return ()
- showPass dflags "CPS"
- -- TODO: check for use of branches to non-existant blocks
- -- TODO: check for use of Sp, SpLim, R1, R2, etc.
- -- continuationC <- return abstractC
- -- TODO: find out if it is valid to create a new unique source like this
- uniqSupply <- mkSplitUniqSupply 'p'
- let (_, continuationC) = runCPS (mapM (mapMCmmTop cpsProc) abstractC) (CPSState uniqSupply)
-
- dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC)
- -- TODO: add option to dump Cmm to file
- return continuationC
projects / ghc-hetmet.git / blobdiff