-module CmmCPS (cmmCPS) where
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
+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 BlockId
import Cmm
import CmmLint
import PprCmm
-import Dataflow -- (fixedpoint, cmmLivenessComment, cmmLiveness, CmmLive)
+import CmmLive
+import CmmBrokenBlock
+import CmmProcPoint
+import CmmCallConv
+import CmmCPSGen
+import CmmUtils
+import ClosureInfo
import MachOp
-import ForeignCall
import CLabel
import SMRep
import Constants
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 cmm_with_calls
+ = do { when (dopt Opt_DoCmmLinting dflags) $
+ do showPass dflags "CmmLint"
+ case firstJust $ map cmmLint cmm_with_calls of
+ Just err -> do printDump err
+ ghcExit dflags 1
+ Nothing -> return ()
+ ; showPass dflags "CPS"
+
+ -- TODO: more lint checking
+ -- check for use of branches to non-existant blocks
+ -- check for use of Sp, SpLim, R1, R2, etc.
+
+ ; uniqSupply <- mkSplitUniqSupply 'p'
+ ; let supplies = listSplitUniqSupply uniqSupply
+ ; let cpsd_cmm = zipWith doCpsProc supplies cmm_with_calls
+
+ ; dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms cpsd_cmm)
---------------------------------------------------------------------------------
--- 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
-
---------------------------------------------------------------------------------
-
--- The format for the call to a continuation
--- The fst is the arguments that must be passed to the continuation
--- by the continuation's caller.
--- The snd is the live values that must be saved on stack.
--- A Nothing indicates an ignored slot.
--- The head of each list is the stack top or the first parameter.
-
--- The format for live values for a particular continuation
--- All on stack for now.
--- Head element is the top of the stack (or just under the header).
--- Nothing means an empty slot.
--- Future possibilities include callee save registers (i.e. passing slots in register)
--- 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
-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
+ -- TODO: add option to dump Cmm to file
---------------------------------------------------------------------------------
--- 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
+ ; return cpsd_cmm }
+
+
+-----------------------------------------------------------------------------
+-- |CPS a single CmmTop (proceedure)
+-- Only 'CmmProc' are transformed 'CmmData' will be left alone.
+-----------------------------------------------------------------------------
+
+doCpsProc :: UniqSupply -> Cmm -> Cmm
+doCpsProc s (Cmm c)
+ = Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c
+
+cpsProc :: UniqSupply
+ -> CmmTop -- ^Input procedure
+ -> [CmmTop] -- ^Output procedures;
+ -- a single input procedure is converted to
+ -- multiple output procedures
+
+-- Data blocks don't need to be CPS transformed
+cpsProc uniqSupply proc@(CmmData _ _) = [proc]
+
+-- Empty functions just don't work with the CPS algorithm, but
+-- they don't need the transformation anyway so just output them directly
+cpsProc uniqSupply proc@(CmmProc _ _ _ (ListGraph []))
+ = pprTrace "cpsProc: unexpected empty proc" (ppr proc) [proc]
+
+-- CPS transform for those procs that actually need it
+-- The plan is this:
+--
+-- * Introduce a stack-check block as the first block
+-- * The first blocks gets a FunctionEntry; the rest are ControlEntry
+-- * Now break each block into a bunch of blocks (at call sites);
+-- all but the first will be ContinuationEntry
+--
+cpsProc uniqSupply (CmmProc info ident params (ListGraph blocks)) = cps_procs
+ where
+ -- We need to be generating uniques for several things.
+ -- We could make this function monadic to handle that
+ -- but since there is no other reason to make it monadic,
+ -- we instead will just split them all up right here.
+ (uniqSupply1, uniqSupply2) = splitUniqSupply uniqSupply
+ uniques :: [[Unique]]
+ uniques = map uniqsFromSupply $ listSplitUniqSupply uniqSupply1
+ (stack_check_block_unique:stack_use_unique:adaptor_uniques) :
+ block_uniques = uniques
+ proc_uniques = map (map (map uniqsFromSupply . listSplitUniqSupply) . listSplitUniqSupply) $ listSplitUniqSupply uniqSupply2
+
+ stack_use = CmmLocal (LocalReg stack_use_unique (cmmRegRep spReg) GCKindPtr)
+ stack_check_block_id = BlockId stack_check_block_unique
+ stack_check_block = make_stack_check stack_check_block_id info stack_use (blockId $ head blocks)
+
+ forced_blocks = stack_check_block : blocks
+
+ CmmInfo maybe_gc_block_id update_frame _ = info
+
+ -- Break the block at each function call.
+ -- The part after the function call will have to become a continuation.
+ broken_blocks :: ([(BlockId, ContFormat)], [BrokenBlock])
+ broken_blocks =
+ (\x -> (concatMap fst x, concatMap snd x)) $
+ zipWith3 (breakBlock (maybeToList maybe_gc_block_id))
+ block_uniques
+ forced_blocks
+ (FunctionEntry info ident params :
+ repeat ControlEntry)
+
+ f' = selectContinuations (fst broken_blocks)
+ broken_blocks' = map (makeContinuationEntries f') $
+ concat $
+ zipWith (adaptBlockToFormat f')
+ adaptor_uniques
+ (snd broken_blocks)
+
+ -- 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 = map (gatherBlocksIntoContinuation live proc_points block_env)
+ (uniqSetToList proc_points)
+
+ -- 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, -- key
+ (CmmFormalsWithoutKinds, -- arguments
+ Maybe CLabel, -- label in top slot
+ [Maybe LocalReg]))] -- slots
+ formats = selectContinuationFormat 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, WordOff, [(CLabel, ContinuationFormat)])
+ formats'@(_, _, format_list) = processFormats formats update_frame continuations
+
+ -- Update the info table data on the continuations with
+ -- the selected stack formats.
+ continuations' :: [Continuation CmmInfo]
+ continuations' = map (applyContinuationFormat format_list) continuations
+
+ -- Do the actual CPS transform.
+ cps_procs :: [CmmTop]
+ cps_procs = zipWith (continuationToProc formats' stack_use) proc_uniques continuations'
+
+make_stack_check stack_check_block_id info stack_use next_block_id =
+ BasicBlock stack_check_block_id $
+ check_stmts ++ [CmmBranch next_block_id]
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)
+ check_stmts =
+ case info of
+ -- If we are given a stack check handler,
+ -- then great, well check the stack.
+ CmmInfo (Just gc_block) _ _
+ -> [CmmCondBranch
+ (CmmMachOp (MO_U_Lt $ cmmRegRep spReg)
+ [CmmReg stack_use, CmmReg spLimReg])
+ gc_block]
+ -- If we aren't given a stack check handler,
+ -- then humph! we just won't check the stack for them.
+ CmmInfo Nothing _ _
+ -> []
+-----------------------------------------------------------------------------
+
+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
- 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]
+ 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 ::
+ BlockEntryLiveness -> UniqSet BlockId -> BlockEnv BrokenBlock
+ -> BlockId -> Continuation (Either C_SRT CmmInfo)
+gatherBlocksIntoContinuation live proc_points blocks start =
+ Continuation info_table clabel params is_gc_cont body
+ where
+ children = (collectNonProcPointTargets proc_points blocks (unitUniqSet start) [start]) `minusUniqSet` (unitUniqSet start)
+ start_block = lookupWithDefaultUFM blocks unknown_block start
+ children_blocks = map (lookupWithDefaultUFM blocks unknown_block) (uniqSetToList children)
+ unknown_block = panic "unknown block in gatherBlocksIntoContinuation"
+ body = start_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 (CmmInfo Nothing Nothing CmmNonInfoTable)
+
+ is_gc_cont = case start_block_entry of
+ FunctionEntry _ _ _ -> False
+ ContinuationEntry _ _ gc_cont -> gc_cont
+ ControlEntry -> False
+
+ 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 ->
+ uniqSetToList $
+ lookupWithDefaultUFM live unknown_block start
+ -- it's a proc-point, pass lives in parameter registers
--------------------------------------------------------------------------------
--- 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 $ 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]
-
--- 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]
--}
+-- For now just select the continuation orders in the order they are in the set with no gaps
---------------------------------------------------------------------------------
--- 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
+selectContinuationFormat :: BlockEnv CmmLive
+ -> [Continuation (Either C_SRT CmmInfo)]
+ -> [(CLabel, (CmmFormalsWithoutKinds, Maybe CLabel, [Maybe LocalReg]))]
+selectContinuationFormat live continuations =
+ map (\c -> (continuationLabel c, selectContinuationFormat' c)) continuations
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
+ -- User written continuations
+ selectContinuationFormat' (Continuation
+ (Right (CmmInfo _ _ (CmmInfoTable _ _ (ContInfo format srt))))
+ label formals _ _) =
+ (formals, Just label, format)
+ -- Either user written non-continuation code
+ -- or CPS generated proc-points
+ selectContinuationFormat' (Continuation (Right _) _ formals _ _) =
+ (formals, Nothing, [])
+ -- CPS generated continuations
+ selectContinuationFormat' (Continuation (Left srt) 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 (formals,
+ Just label,
+ map Just $ uniqSetToList $
+ lookupWithDefaultUFM live unknown_block ident)
+
+ unknown_block = panic "unknown BlockId in selectContinuationFormat"
+
+processFormats :: [(CLabel, (CmmFormalsWithoutKinds, Maybe CLabel, [Maybe LocalReg]))]
+ -> Maybe UpdateFrame
+ -> [Continuation (Either C_SRT CmmInfo)]
+ -> (WordOff, WordOff, [(CLabel, ContinuationFormat)])
+processFormats formats update_frame continuations =
+ (max_size + update_frame_size, update_frame_size, formats')
+ where
+ max_size = maximum $
+ 0 : map (continuationMaxStack formats') continuations
+ formats' = map make_format formats
+ make_format (label, (formals, top, stack)) =
+ (label,
+ ContinuationFormat {
+ continuation_formals = formals,
+ continuation_label = top,
+ continuation_frame_size = stack_size stack +
+ if isJust top
+ then label_size
+ else 0,
+ continuation_stack = stack })
+
+ update_frame_size = case update_frame of
+ Nothing -> 0
+ (Just (UpdateFrame _ args))
+ -> label_size + update_size args
+
+ update_size [] = 0
+ update_size (expr:exprs) = width + update_size exprs
+ where
+ width = machRepByteWidth (cmmExprRep expr) `quot` wORD_SIZE
+ -- TODO: it would be better if we had a machRepWordWidth
+
+ -- 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
+
+continuationMaxStack :: [(CLabel, ContinuationFormat)]
+ -> Continuation a
+ -> WordOff
+continuationMaxStack _ (Continuation _ _ _ True _) = 0
+continuationMaxStack formats (Continuation _ label _ False blocks) =
+ max_arg_size + continuation_frame_size stack_format
+ where
+ stack_format = maybe unknown_format id $ lookup label formats
+ unknown_format = panic "Unknown format in continuationMaxStack"
+
+ max_arg_size = maximum $ 0 : map block_max_arg_size blocks
+
+ block_max_arg_size block =
+ maximum (final_arg_size (brokenBlockExit block) :
+ map stmt_arg_size (brokenBlockStmts block))
+
+ final_arg_size (FinalReturn args) =
+ argumentsSize (cmmExprRep . kindlessCmm) args
+ final_arg_size (FinalJump _ args) =
+ argumentsSize (cmmExprRep . kindlessCmm) args
+ final_arg_size (FinalCall next _ _ args _ _ True) = 0
+ final_arg_size (FinalCall next _ _ args _ _ False) =
+ -- We have to account for the stack used when we build a frame
+ -- for the *next* continuation from *this* continuation
+ argumentsSize (cmmExprRep . kindlessCmm) args +
+ continuation_frame_size next_format
+ where
+ next_format = maybe unknown_format id $ lookup next' formats
+ next' = mkReturnPtLabel $ getUnique next
+
+ final_arg_size _ = 0
+
+ stmt_arg_size (CmmJump _ args) =
+ argumentsSize (cmmExprRep . kindlessCmm) args
+ stmt_arg_size (CmmCall _ _ _ (CmmSafe _) _) =
+ panic "Safe call in processFormats"
+ stmt_arg_size (CmmReturn _) =
+ panic "CmmReturn in processFormats"
+ stmt_arg_size _ = 0
+
+-----------------------------------------------------------------------------
+applyContinuationFormat :: [(CLabel, ContinuationFormat)]
+ -> Continuation (Either C_SRT CmmInfo)
+ -> Continuation CmmInfo
+
+-- User written continuations
+applyContinuationFormat formats (Continuation
+ (Right (CmmInfo gc update_frame (CmmInfoTable prof tag (ContInfo _ srt))))
+ label formals is_gc blocks) =
+ Continuation (CmmInfo gc update_frame (CmmInfoTable prof tag (ContInfo format srt)))
+ label formals is_gc blocks
+ where
+ format = continuation_stack $ maybe unknown_block id $ lookup label formats
+ unknown_block = panic "unknown BlockId in applyContinuationFormat"
+
+-- Either user written non-continuation code or CPS generated proc-point
+applyContinuationFormat formats (Continuation
+ (Right info) label formals is_gc blocks) =
+ Continuation info label formals is_gc blocks
+
+-- CPS generated continuations
+applyContinuationFormat formats (Continuation
+ (Left srt) label formals is_gc blocks) =
+ Continuation (CmmInfo gc Nothing (CmmInfoTable prof tag (ContInfo (continuation_stack $ format) srt)))
+ label formals is_gc 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 may convert it to rET_BIG
+ format = maybe unknown_block id $ lookup label formats
+ unknown_block = panic "unknown BlockId in applyContinuationFormat"
---------------------------------------------------------------------------------
-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