import CmmLint
import PprCmm
-import Dataflow (cmmLivenessComment, cmmLiveness, CmmLive)
+import Dataflow (fixedpoint)
+import CmmLive
import MachOp
import ForeignCall
import CLabel
+import SMRep
+import Constants
import DynFlags
import ErrUtils
import Monad
import IO
-
---------------------------------------------------------------------------------
--- Monad for the CPSer
--- Contains:
--- * State for the uniqSupply
-
-data CPSState = CPSState { cps_uniqs :: UniqSupply }
-
-data CPS a = CPS { runCPS :: CPSState -> (CPSState, a) }
-
-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'
-
---------------------------------------------------------------------------------
--- Utility functions
-
-getState = CPS $ \s -> (s, s)
-putState s = CPS $ \_ -> (s, ())
-
-newLabelCPS = do
- state <- getState
- let (us1, us2) = splitUniqSupply (cps_uniqs state)
- putState $ state { cps_uniqs = us1 }
- return $ BlockId (uniqFromSupply us2)
-
-mapMCmmTop :: (Monad m) => (CmmTop -> m [CmmTop]) -> Cmm -> m Cmm
-mapMCmmTop f (Cmm xs) = liftM Cmm $ liftM concat $ mapM f xs
+import Data.List
--------------------------------------------------------------------------------
-- and heap memory (not sure if that's usefull at all though, but it may
-- be worth exploring the design space).
-data CPSBlockInfo
- = ControlBlock -- Consider whether a proc-point might want arguments on stack
- | ContinuationBlock [(CmmReg,MachHint)] {- params -}
-
-type ContinuationFormat = [Maybe LocalReg] -- TODO: consider params as part of format
+data BrokenBlock
+ = BrokenBlock {
+ brokenBlockId :: BlockId, -- Like a CmmBasicBlock
+ brokenBlockEntry :: BlockEntryInfo,
+ -- How this block can be entered
+
+ brokenBlockStmts :: [CmmStmt],
+ -- Like a CmmBasicBlock
+ -- (but without the last statement)
+
+ brokenBlockTargets :: [BlockId],
+ -- Blocks that this block could
+ -- branch to one either by conditional
+ -- branches or via the last statement
+
+ brokenBlockExit :: FinalStmt
+ -- How the block can be left
+ }
+
+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.
+
+data BlockEntryInfo
+ = FunctionEntry -- Beginning of a function
+ CLabel -- The function name
+ CmmFormals -- Aguments to function
+
+ | ContinuationEntry -- Return point of a call
+ CmmFormals -- return values (argument to continuation)
+ -- TODO:
+ -- | ProcPointEntry -- no return values, but some live might end up as params or possibly in the frame
+
+ | ControlEntry -- A label in the input
+
+-- Final statement in a BlokenBlock
+-- Constructors and arguments match those in Cmm,
+-- but are restricted to branches, returns, jumps, calls and switches
+data FinalStmt
+ = FinalBranch
+ BlockId -- next block (must be a ControlEntry)
+
+ | FinalReturn
+ CmmActuals -- return values
+
+ | FinalJump
+ CmmExpr -- the function to call
+ CmmActuals -- arguments to call
+
+ | FinalCall
+ 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)
+
+ | FinalSwitch
+ CmmExpr [Maybe BlockId] -- Table branch
+
+ -- TODO: | ProcPointExit (needed?)
+
+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 -}
-- 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
-type CmmParam = [(CmmReg,MachHint)]
+blocksToBlockEnv :: [BrokenBlock] -> BlockEnv BrokenBlock
+blocksToBlockEnv blocks = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks
+
+-----------------------------------------------------------------------------
+calculateOwnership :: UniqSet BlockId -> [BrokenBlock] -> BlockEnv (UniqSet BlockId)
+calculateOwnership proc_points blocks =
+ fixedpoint dependants update (map brokenBlockId blocks) emptyUFM
+ where
+ blocks_ufm :: BlockEnv BrokenBlock
+ blocks_ufm = blocksToBlockEnv blocks
+
+ dependants :: BlockId -> [BlockId]
+ dependants ident =
+ brokenBlockTargets $ lookupWithDefaultUFM
+ blocks_ufm unknown_block ident
+
+ update :: BlockId -> Maybe BlockId
+ -> BlockEnv (UniqSet BlockId) -> Maybe (BlockEnv (UniqSet BlockId))
+ update ident cause owners =
+ case (cause, ident `elementOfUniqSet` proc_points) of
+ (Nothing, True) -> Just $ addToUFM owners ident (unitUniqSet ident)
+ (Nothing, False) -> Nothing
+ (Just cause', True) -> Nothing
+ (Just cause', False) ->
+ if (sizeUniqSet old) == (sizeUniqSet new)
+ then Nothing
+ else Just $ addToUFM owners ident new
+ where
+ old = lookupWithDefaultUFM owners emptyUniqSet ident
+ new = old `unionUniqSets` lookupWithDefaultUFM owners emptyUniqSet cause'
+
+ unknown_block = panic "unknown BlockId in selectStackFormat"
+
+calculateProcPoints :: [BrokenBlock] -> UniqSet BlockId
+calculateProcPoints blocks = calculateProcPoints' init_proc_points blocks
+ where
+ init_proc_points = mkUniqSet $
+ map brokenBlockId $
+ filter always_proc_point blocks
+ always_proc_point BrokenBlock {
+ brokenBlockEntry = FunctionEntry _ _ } = True
+ always_proc_point BrokenBlock {
+ brokenBlockEntry = ContinuationEntry _ } = True
+ always_proc_point _ = False
+
+calculateProcPoints' :: UniqSet BlockId -> [BrokenBlock] -> UniqSet BlockId
+calculateProcPoints' old_proc_points blocks =
+ if sizeUniqSet old_proc_points == sizeUniqSet new_proc_points
+ then old_proc_points
+ else calculateProcPoints' new_proc_points blocks
+ where
+ owners = calculateOwnership old_proc_points blocks
+ new_proc_points = unionManyUniqSets (old_proc_points:(map (calculateProcPoints'' owners) blocks))
+
+calculateProcPoints'' :: BlockEnv (UniqSet BlockId) -> BrokenBlock -> UniqSet BlockId
+calculateProcPoints'' owners block =
+ unionManyUniqSets (map (f parent_id) child_ids)
+ where
+ parent_id = brokenBlockId block
+ child_ids = brokenBlockTargets block
+ -- TODO: name for f
+ f parent_id child_id =
+ if needs_proc_point
+ then unitUniqSet child_id
+ else emptyUniqSet
+ where
+ parent_owners = lookupWithDefaultUFM owners emptyUniqSet parent_id
+ child_owners = lookupWithDefaultUFM owners emptyUniqSet child_id
+ needs_proc_point = not $ isEmptyUniqSet $ child_owners `minusUniqSet` parent_owners
+
+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)
+
+buildContinuation ::
+ UniqSet BlockId -> BlockEnv BrokenBlock
+ -> BlockId -> Continuation
+buildContinuation 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
-selectContinuationFormat :: UniqFM {-BlockId-} CmmParam -> UniqFM {-BlockId-} CmmLive -> UniqFM {-BlockId-} ContinuationFormat
-selectContinuationFormat param live = mapUFM (map Just . uniqSetToList) live
-
-transformReturn block_infos formats (BasicBlock ident stmts) =
- case last $ init stmts of
- CmmReturn arguments ->
- BasicBlock ident $ (init $ init stmts) ++
- [CmmJump (CmmReg spReg) arguments]
- -- TODO: tail calls
- -- TODO: return direct at the end of a block
- _ -> BasicBlock ident stmts
-
-destructContinuation :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} ContinuationFormat -> CmmBasicBlock -> CmmBasicBlock
-destructContinuation block_infos formats (BasicBlock ident stmts) =
- case info of
- ControlBlock -> BasicBlock ident stmts
- ContinuationBlock _ -> BasicBlock ident (unpack_continuation ++ stmts)
- where
- info = lookupWithDefaultUFM block_infos (panic $ "info: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident
- format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident
- unpack_continuation = CmmAssign spReg (CmmRegOff spReg frame_size) :
- [CmmAssign (CmmLocal reg) (CmmLoad (CmmRegOff spReg (i*stack_slot_size)) (localRegRep reg))
- | (i, Just reg) <- zip [1..] format]
- frame_size = stack_header_size + stack_slot_size * (length format)
- stack_header_size = stack_slot_size -- TODO: check if this could be different than stack_slot_size
- stack_slot_size = 4 -- TODO: find actual variables to be used instead of this
-
-constructContinuation :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} ContinuationFormat -> 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 ++
- [CmmJump target arguments]
- CmmCall target results arguments _ -> panic "unimplemented CmmCall"
- _ -> BasicBlock ident $ (init stmts) ++ build_block_branch
- where
- info = lookupWithDefaultUFM block_infos (panic $ "info: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) next_block
- format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) next_block
- 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)"
- next_block_as_proc_expr = CmmLit $ CmmLabel $ mkReturnPtLabel $ getUnique next_block
- pack_continuation = CmmAssign spReg (CmmRegOff spReg (-frame_size)) :
- CmmStore (CmmReg spReg) next_block_as_proc_expr :
- [CmmStore (CmmRegOff spReg (i*stack_slot_size)) (CmmReg $ CmmLocal reg)
- | (i, Just reg) <- zip [1..] format]
- frame_size = stack_header_size + stack_slot_size * (length format)
- stack_header_size = stack_slot_size -- TODO: check if this could be different than stack_slot_size (e.g. fixedHdrSize depends on PAR and GRAN)
- stack_slot_size = 4 -- TODO: find actual variables to be used instead of this (e.g. cgRepSizeW)
- 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]
-
--- 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
- let live = cmmLiveness (map snd broken_blocks)
- let blocks_with_live = map (cmmLivenessComment live . snd) broken_blocks
- let formats = selectContinuationFormat (undefined {-TODO-}) live
- 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 blocks_with_live''']
+
+selectStackFormat :: BlockEnv CmmLive -> [BrokenBlock] -> BlockEnv StackFormat
+selectStackFormat live blocks =
+ fixedpoint dependants update (map brokenBlockId blocks) emptyUFM
+ where
+ blocks_ufm :: BlockEnv BrokenBlock
+ blocks_ufm = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks
+
+ dependants :: BlockId -> [BlockId]
+ dependants ident =
+ brokenBlockTargets $ lookupWithDefaultUFM
+ blocks_ufm unknown_block ident
+
+ update :: BlockId -> Maybe BlockId
+ -> BlockEnv StackFormat -> Maybe (BlockEnv StackFormat)
+ update ident cause formats =
+ if ident `elemUFM` formats
+ then Nothing -- Blocks only need to be updated once
+ else case (cause,
+ brokenBlockEntry $ lookupWithDefaultUFM blocks_ufm
+ unknown_block ident) of
+ -- Propagate only to blocks entered by branches
+ -- (not function entry blocks or continuation entry blocks)
+ (Just cause_name, ControlEntry) ->
+ Just $ addToUFM formats ident cause_format
+ where cause_format = lookupWithDefaultUFM
+ formats unknown_block
+ cause_name
+ -- Do initial calculates for function blocks
+ (Nothing, FunctionEntry _ _) ->
+ Just $
+ addToUFM formats ident $
+ StackFormat ident 0 []
+ -- Do initial calculates for continuation blocks
+ (Nothing, ContinuationEntry _) ->
+ Just $
+ addToUFM formats ident $
+ live_to_format ident $
+ lookupWithDefaultUFM live unknown_block ident
+ _ -> Nothing
+
+ unknown_block = panic "unknown BlockId in selectStackFormat"
+
+ live_to_format :: BlockId -> CmmLive -> StackFormat
+ 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)
+
+selectStackFormat2 :: BlockEnv CmmLive -> [Continuation] -> [(CLabel, StackFormat)]
+selectStackFormat2 live continuations =
+ map (\c -> (continuationLabel c, selectStackFormat' c)) continuations
+ where
+ selectStackFormat' (Continuation True info_table label formals blocks) =
+ let ident = brokenBlockId $ head blocks -- TODO: CLabel isn't a uniquable, but we need a better way than this
+ in StackFormat ident 0 []
+ selectStackFormat' (Continuation False info_table label formals blocks) =
+ let ident = brokenBlockId $ head blocks -- TODO: CLabel isn't a uniquable, but we need a better way than this
+ in live_to_format ident $ lookupWithDefaultUFM live unknown_block ident
+
+ live_to_format :: BlockId -> CmmLive -> StackFormat
+ 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)
+
+ unknown_block = panic "unknown BlockId in selectStackFormat"
+
+slot_size reg = ((machRepByteWidth (localRegRep reg) - 1) `div` wORD_SIZE) + 1
+
+constructContinuation :: [(CLabel, StackFormat)] -> Continuation -> CmmTop
+constructContinuation formats (Continuation is_entry info label formals blocks) =
+ CmmProc info label formals (map (constructContinuation2' label formats) blocks)
+
+constructContinuation2' :: CLabel -> [(CLabel, StackFormat)] -> BrokenBlock
+ -> CmmBasicBlock
+constructContinuation2' 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 constructContinuation"
+ 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
+ -- TODO: do something about global saves
+ FinalCall next (CmmForeignCall target CmmCallConv)
+ results arguments saves ->
+ 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 saves -> panic "unimplemented CmmCall"
--------------------------------------------------------------------------------
+-- Functions that generate CmmStmt sequences
+-- for packing/unpacking continuations
+-- and entering/exiting functions
+
+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))]
+ jump = [CmmJump target arguments]
+
+enter_function :: WordOff -> [CmmStmt]
+enter_function max_frame_size
+ = check_stack_limit where
+ check_stack_limit = [
+ CmmCondBranch
+ (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
+
+-- TODO: fix branches to proc point (we have to insert a new block to marshel the continuation)
+pack_continuation :: StackFormat -> StackFormat -> [CmmStmt]
+pack_continuation (StackFormat curr_id curr_frame_size curr_offsets)
+ (StackFormat cont_id cont_frame_size cont_offsets)
+ = save_live_values ++ set_stack_header ++ adjust_spReg where
+ -- TODO: only save variables when actually needed
+ save_live_values =
+ [CmmStore
+ (CmmRegOff
+ 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 {-TODO: use the correct function -} $ getUnique cont_id
+ adjust_spReg =
+ if curr_frame_size == cont_frame_size
+ then []
+ else [CmmAssign spReg (CmmRegOff spReg ((curr_frame_size - cont_frame_size)*wORD_SIZE))]
+
+-- Lazy adjustment of stack headers assumes all blocks
+-- that could branch to eachother (i.e. control blocks)
+-- have the same stack format (this causes a problem
+-- only for proc-point).
+unpack_continuation :: StackFormat -> [CmmStmt]
+unpack_continuation (StackFormat curr_id curr_frame_size curr_offsets)
+ = load_live_values where
+ -- TODO: only save variables when actually needed
+ load_live_values =
+ [CmmAssign
+ reg
+ (CmmLoad (CmmRegOff spReg (wORD_SIZE*offset)) (cmmRegRep reg))
+ | (reg, offset) <- curr_offsets]
+
+-----------------------------------------------------------------------------
+-- Breaking basic blocks on function calls
+-----------------------------------------------------------------------------
+
+-----------------------------------------------------------------------------
+-- Takes a basic block and breaks it up into a list of broken blocks
+--
-- 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
+-- be arguments to the continuation of the block once the call (if any)
+-- returns.
+
+breakBlock :: [Unique] -> CmmBasicBlock -> BlockEntryInfo -> [BrokenBlock]
+breakBlock uniques (BasicBlock ident stmts) entry =
+ breakBlock' uniques ident entry [] [] stmts where
+ breakBlock' uniques current_id entry exits accum_stmts stmts =
+ case stmts of
+ [] -> panic "block doesn't end in jump, goto or return"
+ [CmmJump target arguments] ->
+ [BrokenBlock current_id entry accum_stmts
+ exits
+ (FinalJump target arguments)]
+ [CmmReturn arguments] ->
+ [BrokenBlock current_id entry accum_stmts
+ exits
+ (FinalReturn arguments)]
+ [CmmBranch target] ->
+ [BrokenBlock current_id entry accum_stmts
+ (target:exits)
+ (FinalBranch target)]
+ [CmmSwitch expr targets] ->
+ [BrokenBlock current_id entry accum_stmts
+ (mapMaybe id targets ++ exits)
+ (FinalSwitch expr targets)]
+ (CmmJump _ _:_) ->
+ panic "jump in middle of block"
+ (CmmReturn _:_) ->
+ panic "return in middle of block"
+ (CmmBranch _:_) ->
+ panic "branch in middle of block"
+ (CmmSwitch _ _:_) ->
+ panic ("switch in middle of block" ++ (showSDoc $ ppr stmts))
+ (CmmCall target results arguments saves:stmts) -> block : rest
+ where
+ new_id = BlockId $ head uniques
+ block = BrokenBlock current_id entry accum_stmts
+ (new_id:exits)
+ (FinalCall new_id target results arguments saves)
+ rest = breakBlock' (tail uniques) new_id
+ (ContinuationEntry results) [] [] stmts
+ (s@(CmmCondBranch test target):stmts) ->
+ breakBlock' uniques current_id entry
+ (target:exits) (accum_stmts++[s]) stmts
+ (s:stmts) ->
+ breakBlock' uniques current_id entry
+ exits (accum_stmts++[s]) stmts
+
+--------------------------------
+-- Convert from a BrokenBlock
+-- to a CmmBasicBlock so the
+-- liveness analysis can run
+-- on it.
+--------------------------------
+cmmBlockFromBrokenBlock :: BrokenBlock -> CmmBasicBlock
+cmmBlockFromBrokenBlock (BrokenBlock ident _ stmts _ exit) =
+ BasicBlock ident (stmts++exit_stmt)
+ where
+ exit_stmt =
+ case exit of
+ FinalBranch target -> [CmmBranch target]
+ FinalReturn arguments -> [CmmReturn arguments]
+ FinalJump target arguments -> [CmmJump target arguments]
+ FinalSwitch expr targets -> [CmmSwitch expr targets]
+ FinalCall branch_target call_target results arguments saves ->
+ [CmmCall call_target results arguments saves,
+ CmmBranch branch_target]
+
+-----------------------------------------------------------------------------
+-- CPS a single CmmTop (proceedure)
+-----------------------------------------------------------------------------
+
+cpsProc :: UniqSupply -> CmmTop -> [CmmTop]
+cpsProc uniqSupply x@(CmmData _ _) = [x]
+cpsProc uniqSupply x@(CmmProc info_table ident params blocks) =
+ --[CmmProc info_table ident params cps_blocks]
+ cps_continuations
+ where
+ uniqes :: [[Unique]]
+ uniqes = map uniqsFromSupply $ listSplitUniqSupply uniqSupply
+
+ -- Break the block at each function call
+ broken_blocks :: [BrokenBlock]
+ broken_blocks = concat $ zipWith3 breakBlock uniqes blocks
+ (FunctionEntry ident params:repeat ControlEntry)
+
+ -- Calculate live variables for each broken block
+ live :: BlockEntryLiveness
+ live = cmmLiveness $ map cmmBlockFromBrokenBlock broken_blocks
+ -- nothing can be live on entry to the first block so we could take the tail
+
+ proc_points :: UniqSet BlockId
+ proc_points = calculateProcPoints broken_blocks
+
+ continuations :: [Continuation]
+ continuations = map (buildContinuation proc_points (blocksToBlockEnv broken_blocks)) (uniqSetToList proc_points)
+
+ -- 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
+
+ -- TODO: let blocks_with_live = map (cmmLivenessComment live . snd) broken_blocks
+
+ --procs = groupBlocksIntoContinuations live broken_blocks
+
+ -- Select the stack format on entry to each block
+ formats2 :: [(CLabel, StackFormat)]
+ formats2 = selectStackFormat2 live continuations
+
+ -- Do the actual CPS transform
+ cps_continuations :: [CmmTop]
+ cps_continuations = map (constructContinuation formats2) continuations
--------------------------------------------------------------------------------
cmmCPS :: DynFlags
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)
+ let supplies = listSplitUniqSupply uniqSupply
+ let continuationC = zipWith (\s (Cmm c) -> Cmm $ concat $ zipWith (cpsProc) (listSplitUniqSupply s) c) supplies abstractC
dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC)
-- TODO: add option to dump Cmm to file