-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 CmmLive
+import CmmBrokenBlock
+import CmmProcPoint
+import CmmCallConv
+import CmmInfo
+import CmmUtils
+import Bitmap
+import ClosureInfo
import MachOp
import ForeignCall
import CLabel
import Monad
import IO
+import Data.List
+
+-----------------------------------------------------------------------------
+-- |Top level driver for the CPS pass
+-----------------------------------------------------------------------------
+cmmCPS :: DynFlags -- ^ Dynamic flags: -dcmm-lint -ddump-cps-cmm
+ -> [GenCmm CmmStatic CmmInfo CmmStmt] -- ^ Input C-- with Proceedures
+ -> IO [GenCmm CmmStatic [CmmStatic] CmmStmt] -- ^ 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 }
-
-data CPS a = CPS { runCPS :: CPSState -> (CPSState, a) }
+ -- TODO: more lint checking
+ -- check for use of branches to non-existant blocks
+ -- check for use of Sp, SpLim, R1, R2, etc.
-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'
+ 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
---------------------------------------------------------------------------------
--- Utility functions
+ dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC)
-getState = CPS $ \s -> (s, s)
-putState s = CPS $ \_ -> (s, ())
+ -- TODO: add option to dump Cmm to file
-newLabelCPS = do
- state <- getState
- let (us1, us2) = splitUniqSupply (cps_uniqs state)
- putState $ state { cps_uniqs = us1 }
- return $ BlockId (uniqFromSupply us2)
+ return continuationC
-mapMCmmTop :: (Monad m) => (CmmTop -> m [CmmTop]) -> Cmm -> m Cmm
-mapMCmmTop f (Cmm xs) = liftM Cmm $ liftM concat $ mapM f xs
+stg_gc_gen = mkRtsApFastLabel SLIT("gen_cg_TODO") --panic "Need the label for gc"
+make_gc_block block_id fun_label formals safety = BasicBlock block_id stmts
+ where
+ stmts = [CmmCall stg_gc_gen_target [] [] safety,
+ CmmJump fun_expr actuals]
+ stg_gc_gen_target =
+ CmmForeignCall (CmmLit (CmmLabel stg_gc_gen)) CmmCallConv
+ actuals = map (\x -> (CmmReg (CmmLocal x), NoHint)) formals
+ fun_expr = CmmLit (CmmLabel fun_label)
+
+force_gc_block old_info block_id fun_label formals blocks =
+ case old_info of
+ CmmNonInfo (Just _) -> (old_info, [])
+ CmmInfo _ (Just _) _ _ -> (old_info, [])
+ CmmNonInfo Nothing
+ -> (CmmNonInfo (Just block_id),
+ [make_gc_block block_id fun_label formals (CmmSafe NoC_SRT)])
+ CmmInfo prof Nothing type_tag type_info
+ -> (CmmInfo prof (Just block_id) type_tag type_info,
+ [make_gc_block block_id fun_label formals (CmmSafe srt)])
+ where
+ srt = case type_info of
+ ConstrInfo _ _ _ -> NoC_SRT
+ FunInfo _ srt' _ _ _ _ -> srt'
+ ThunkInfo _ srt' -> srt'
+ ThunkSelectorInfo _ srt' -> srt'
+ ContInfo _ srt' -> srt'
+
+-----------------------------------------------------------------------------
+-- |CPS a single CmmTop (proceedure)
+-- Only 'CmmProc' are transformed 'CmmData' will be left alone.
+-----------------------------------------------------------------------------
+
+cpsProc :: UniqSupply
+ -> GenCmmTop CmmStatic CmmInfo CmmStmt -- ^Input proceedure
+ -> [GenCmmTop CmmStatic [CmmStatic] CmmStmt] -- ^Output proceedure and continuations
+cpsProc uniqSupply (CmmData sec dat) = [CmmData sec dat]
+cpsProc uniqSupply (CmmProc info ident params blocks) = info_procs
+ where
+ uniques :: [[Unique]]
+ uniques = map uniqsFromSupply $ listSplitUniqSupply uniqSupply
+ (gc_unique:info_uniques):block_uniques = uniques
+
+ -- Ensure that
+ forced_gc :: (CmmInfo, [CmmBasicBlock])
+ forced_gc = force_gc_block info (BlockId gc_unique) ident params blocks
+
+ forced_info = fst forced_gc
+ forced_blocks = blocks ++ snd forced_gc
+ forced_gc_id = case forced_info of
+ CmmNonInfo (Just x) -> x
+ CmmInfo _ (Just x) _ _ -> x
+
+ -- 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 block_uniques forced_blocks
+ (FunctionEntry forced_info 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 (Either C_SRT CmmInfo)]
+ continuations = zipWith
+ (gatherBlocksIntoContinuation proc_points block_env)
+ (uniqSetToList proc_points)
+ (Just forced_gc_id : repeat Nothing)
+
+ -- Select the stack format on entry to each continuation.
+ -- Return the max stack offset and an association list
+ --
+ -- This is an association list instead of a UniqFM because
+ -- CLabel's don't have a 'Uniqueable' instance.
+ formats :: [(CLabel, (Maybe CLabel, [Maybe LocalReg]))]
+ formats = selectStackFormat live continuations
+
+ -- Do a little meta-processing on the stack formats such as
+ -- getting the individual frame sizes and the maximum frame size
+ formats' :: (WordOff, [(CLabel, StackFormat)])
+ formats' = processFormats formats
+
+ -- TODO FIXME NOW: calculate a real max stack (including function call args)
+ -- TODO: from the maximum frame size get the maximum stack size.
+ -- The difference is due to the size taken by function calls.
+
+ -- Update the info table data on the continuations with
+ -- the selected stack formats.
+ continuations' :: [Continuation CmmInfo]
+ continuations' = map (applyStackFormat (snd formats')) continuations
+
+ -- Do the actual CPS transform.
+ cps_procs :: [CmmTop]
+ cps_procs = map (continuationToProc formats') continuations'
+
+ -- Convert the info tables from CmmInfo to [CmmStatic]
+ -- We might want to put this in another pass eventually
+ info_procs :: [RawCmmTop]
+ info_procs = concat (zipWith mkInfoTable info_uniques cps_procs)
--------------------------------------------------------------------------------
-- 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?)
+continuationLabel (Continuation _ l _ _) = l
+data Continuation info =
+ Continuation
+ info --(Either C_SRT CmmInfo) -- Left <=> Continuation created by the CPS
+ -- Right <=> Function or Proc point
+ 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 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
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 -}
+ = StackFormat {
+ stack_label :: Maybe CLabel, -- The label occupying the top slot
+ stack_frame_size :: WordOff, -- Total frame size in words (not including arguments)
+ stack_live :: [Maybe LocalReg] -- 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 new_blocks =
+ if sizeUniqSet current_targets == sizeUniqSet new_targets
+ then current_targets
+ else foldl
+ (collectNonProcPointTargets proc_points blocks)
+ new_targets
+ (map (:[]) targets)
+ where
+ blocks' = map (lookupWithDefaultUFM blocks (panic "TODO")) new_blocks
+ 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 $ (unionManyUniqSets $ map (mkUniqSet . brokenBlockTargets) blocks')
+ `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 -> Maybe BlockId -> Continuation (Either C_SRT CmmInfo)
+gatherBlocksIntoContinuation proc_points blocks start gc =
+ Continuation info_table clabel params body
+ where
+ start_and_gc = start : maybeToList gc
+ children = (collectNonProcPointTargets proc_points blocks (mkUniqSet start_and_gc) start_and_gc) `minusUniqSet` (mkUniqSet start_and_gc)
+ start_block = lookupWithDefaultUFM blocks (panic "TODO") start
+ gc_block = map (lookupWithDefaultUFM blocks (panic "TODO)")) (maybeToList gc)
+ children_blocks = map (lookupWithDefaultUFM blocks (panic "TODO")) (uniqSetToList children)
+ body = start_block : gc_block ++ children_blocks
+
+ -- We can't properly annotate the continuation's stack parameters
+ -- at this point because this is before stack selection
+ -- but we want to keep the C_SRT around so we use 'Either'.
+ info_table = case start_block_entry of
+ FunctionEntry info _ _ -> Right info
+ ContinuationEntry _ srt -> Left srt
+ ControlEntry -> Right (CmmNonInfo Nothing)
+
+ start_block_entry = brokenBlockEntry start_block
+ 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 (Either C_SRT CmmInfo)]
+ -> [(CLabel, (Maybe CLabel, [Maybe LocalReg]))]
+selectStackFormat live continuations =
+ map (\c -> (continuationLabel c, selectStackFormat' c)) continuations
+ where
+ selectStackFormat' (Continuation
+ (Right (CmmInfo _ _ _ (ContInfo format srt)))
+ label _ _) = (Just label, format)
+ selectStackFormat' (Continuation (Right _) _ _ _) = (Nothing, [])
+ selectStackFormat' (Continuation (Left srt) label _ 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 (Just label,
+ map Just $ uniqSetToList $
+ lookupWithDefaultUFM live unknown_block ident)
+
+ unknown_block = panic "unknown BlockId in selectStackFormat"
+
+processFormats :: [(CLabel, (Maybe CLabel, [Maybe LocalReg]))]
+ -> (WordOff, [(CLabel, StackFormat)])
+processFormats formats = (max_size, formats')
where
- live_to_format (unique, live) = (unique, format) where
- format = foldl extend_format
- (StackFormat (BlockId unique) 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 :: 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)
+ max_size = foldl max 0 (map (stack_frame_size . snd) formats')
+ formats' = map make_format formats
+ make_format (label, format) =
+ (label,
+ StackFormat {
+ stack_label = fst format,
+ stack_frame_size = stack_size (snd format) +
+ if isJust (fst format)
+ then label_size
+ else 0,
+ stack_live = snd format })
+
+ -- TODO: get rid of "+ 1" etc.
+ label_size = 1 :: WordOff
+
+ stack_size [] = 0
+ stack_size (Nothing:formats) = 1 + stack_size formats -- one dead word
+ stack_size (Just reg:formats) = width + stack_size formats
+ where
+ width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE
+ -- TODO: it would be better if we had a machRepWordWidth
+
+-----------------------------------------------------------------------------
+applyStackFormat :: [(CLabel, StackFormat)]
+ -> Continuation (Either C_SRT CmmInfo)
+ -> Continuation CmmInfo
+
+-- User written continuations
+applyStackFormat formats (Continuation
+ (Right (CmmInfo prof gc tag (ContInfo _ srt)))
+ label formals blocks) =
+ Continuation (CmmInfo prof gc tag (ContInfo format srt))
+ label formals 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]
+ format = stack_live $ maybe unknown_block id $ lookup label formats
+ unknown_block = panic "unknown BlockId in applyStackFormat"
---------------------------------------------------------------------------------
+-- User written non-continuation code
+applyStackFormat formats (Continuation (Right info) label formals blocks) =
+ Continuation info label formals blocks
+
+-- CPS generated continuations
+applyStackFormat formats (Continuation (Left srt) label formals blocks) =
+ Continuation (CmmInfo prof gc tag (ContInfo (stack_live $ format) srt))
+ label formals blocks
+ where
+ gc = Nothing -- Generated continuations never need a stack check
+ -- TODO prof: this is the same as the current implementation
+ -- but I think it could be improved
+ prof = ProfilingInfo zeroCLit zeroCLit
+ tag = rET_SMALL -- cmmToRawCmm will convert this to rET_BIG if needed
+ format = maybe unknown_block id $ lookup label formats
+ unknown_block = panic "unknown BlockId in applyStackFormat"
+
+-----------------------------------------------------------------------------
+continuationToProc :: (WordOff, [(CLabel, StackFormat)])
+ -> Continuation CmmInfo
+ -> CmmTop
+continuationToProc (max_stack, formats)
+ (Continuation info label formals blocks) =
+ CmmProc info label formals (map continuationToProc' blocks)
+ where
+ curr_format = maybe unknown_block id $ lookup label formats
+ unknown_block = panic "unknown BlockId in continuationToProc"
+
+ continuationToProc' :: BrokenBlock -> CmmBasicBlock
+ continuationToProc' (BrokenBlock ident entry stmts _ exit) =
+ BasicBlock ident (prefix++stmts++postfix)
+ where
+ prefix = case entry of
+ ControlEntry -> []
+ FunctionEntry (CmmInfo _ (Just gc_block) _ _) _ formals ->
+ gc_stack_check gc_block max_stack ++
+ function_entry formals curr_format
+ FunctionEntry (CmmInfo _ Nothing _ _) _ formals ->
+ panic "continuationToProc: missing GC block"
+ FunctionEntry (CmmNonInfo (Just gc_block)) _ formals ->
+ gc_stack_check gc_block max_stack ++
+ function_entry formals curr_format
+ FunctionEntry (CmmNonInfo Nothing) _ formals ->
+ panic "continuationToProc: missing non-info GC block"
+ ContinuationEntry formals _ ->
+ function_entry formals curr_format
+ postfix = case exit of
+ FinalBranch next -> [CmmBranch next]
+ FinalSwitch expr targets -> [CmmSwitch expr targets]
+ FinalReturn arguments ->
+ tail_call (stack_frame_size curr_format)
+ (CmmLoad (CmmReg spReg) wordRep)
+ arguments
+ FinalJump target arguments ->
+ tail_call (stack_frame_size curr_format) target arguments
+ FinalCall next (CmmForeignCall target CmmCallConv)
+ results arguments ->
+ pack_continuation curr_format cont_format ++
+ tail_call (stack_frame_size curr_format - stack_frame_size cont_format)
+ 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
-- 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))]
+tail_call :: WordOff -> CmmExpr -> CmmActuals -> [CmmStmt]
+tail_call spRel target arguments
+ = store_arguments ++ adjust_spReg ++ jump where
+ store_arguments =
+ [stack_put spRel expr offset
+ | ((expr, _), StackParam offset) <- argument_formats] ++
+ [global_put expr global
+ | ((expr, _), RegisterParam global) <- argument_formats]
+ adjust_spReg =
+ if spRel == 0
+ then []
+ else [CmmAssign spReg (CmmRegOff spReg (spRel*wORD_SIZE))]
jump = [CmmJump target arguments]
-enter_function :: WordOff -> [CmmStmt]
-enter_function max_frame_size
+ argument_formats = assignArguments (cmmExprRep . fst) arguments
+
+gc_stack_check :: BlockId -> WordOff -> [CmmStmt]
+gc_stack_check gc_block max_frame_size
= check_stack_limit where
check_stack_limit = [
CmmCondBranch
(CmmMachOp (MO_U_Lt $ cmmRegRep spReg)
- [CmmRegOff spReg max_frame_size, CmmReg spLimReg])
+ [CmmRegOff spReg (-max_frame_size*wORD_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)
+-- 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
+pack_continuation (StackFormat curr_id curr_frame_size _)
+ (StackFormat cont_id cont_frame_size live_regs)
+ = store_live_values ++ set_stack_header 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)
+ -- (may be handled by latter pass)
+ store_live_values =
+ [stack_put spRel (CmmReg (CmmLocal reg)) offset
| (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
- adjust_spReg =
- if curr_frame_size == cont_frame_size
- then []
- else [CmmAssign spReg (CmmRegOff spReg ((curr_frame_size - cont_frame_size)*wORD_SIZE))]
+ set_stack_header =
+ if needs_header_set
+ then [stack_put spRel continuation_function 0]
+ else []
+
+ -- TODO: factor with function_entry and CmmInfo.hs(?)
+ cont_offsets = mkOffsets label_size live_regs
+
+ label_size = 1 :: WordOff
+
+ mkOffsets size [] = []
+ mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs
+ mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs
+ where
+ width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE
+ -- TODO: it would be better if we had a machRepWordWidth
+
+ spRel = curr_frame_size - cont_frame_size
+ continuation_function = CmmLit $ CmmLabel $ fromJust cont_id
+ needs_header_set =
+ case (curr_id, cont_id) of
+ (Just x, Just y) -> x /= y
+ _ -> isJust cont_id
-- 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
+function_entry :: CmmFormals -> StackFormat -> [CmmStmt]
+function_entry formals (StackFormat _ _ live_regs)
+ = load_live_values ++ load_args where
-- TODO: only save variables when actually needed
+ -- (may be handled by latter pass)
load_live_values =
- [CmmAssign
- reg
- (CmmLoad (CmmRegOff spReg (wORD_SIZE*offset)) (cmmRegRep reg))
+ [stack_get 0 reg offset
| (reg, offset) <- curr_offsets]
+ load_args =
+ [stack_get 0 reg offset
+ | (reg, StackParam offset) <- argument_formats] ++
+ [global_get reg global
+ | (reg, RegisterParam global) <- argument_formats]
+
+ argument_formats = assignArguments (localRegRep) formals
+
+ -- TODO: eliminate copy/paste with pack_continuation
+ curr_offsets = mkOffsets label_size live_regs
+
+ label_size = 1 :: WordOff
+
+ mkOffsets size [] = []
+ mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs
+ mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs
+ where
+ width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE
+ -- TODO: it would be better if we had a machRepWordWidth
+
+-----------------------------------------------------------------------------
+-- Section: Stack and argument register puts and gets
+-----------------------------------------------------------------------------
+-- TODO: document
+
+-- |Construct a 'CmmStmt' that will save a value on the stack
+stack_put :: WordOff -- ^ Offset from the real 'Sp' that 'offset'
+ -- is relative to (added to offset)
+ -> CmmExpr -- ^ What to store onto the stack
+ -> WordOff -- ^ Where on the stack to store it
+ -- (positive <=> higher addresses)
+ -> CmmStmt
+stack_put spRel expr offset =
+ CmmStore (CmmRegOff spReg (wORD_SIZE*(spRel + offset))) expr
+
+--------------------------------
+-- |Construct a
+stack_get :: WordOff
+ -> LocalReg
+ -> WordOff
+ -> CmmStmt
+stack_get spRel reg offset =
+ CmmAssign (CmmLocal reg)
+ (CmmLoad (CmmRegOff spReg (wORD_SIZE*(spRel + offset)))
+ (localRegRep reg))
+global_put :: CmmExpr -> GlobalReg -> CmmStmt
+global_put expr global = CmmAssign (CmmGlobal global) expr
+global_get :: LocalReg -> GlobalReg -> CmmStmt
+global_get reg global = CmmAssign (CmmLocal reg) (CmmReg (CmmGlobal global))
--- 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