+{-# 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.
#include "HsVersions.h"
+import BlockId
import Cmm
import CmmLint
import PprCmm
import CmmBrokenBlock
import CmmProcPoint
import CmmCallConv
-import CmmInfo
+import CmmCPSGen
import CmmUtils
-import Bitmap
import ClosureInfo
import MachOp
-import ForeignCall
import CLabel
import SMRep
import Constants
-- |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"
+ -> [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 doCpsProc s (Cmm c) =
- Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c
- let continuationC = zipWith doCpsProc supplies abstractC
+ ; 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 continuationC)
+ ; dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms cpsd_cmm)
-- TODO: add option to dump Cmm to file
- return continuationC
+ ; return cpsd_cmm }
-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.
-----------------------------------------------------------------------------
+doCpsProc :: UniqSupply -> Cmm -> Cmm
+doCpsProc s (Cmm c)
+ = Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c
+
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
+ -> 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 uniqSupply
- (gc_unique:info_uniques):block_uniques = uniques
+ 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)
- -- Ensure that
- forced_gc :: (CmmInfo, [CmmBasicBlock])
- forced_gc = force_gc_block info (BlockId gc_unique) ident params blocks
+ forced_blocks = stack_check_block : 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
+ 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 :: [BrokenBlock]
+ broken_blocks :: ([(BlockId, ContFormat)], [BrokenBlock])
broken_blocks =
- concat $ zipWith3 breakBlock block_uniques forced_blocks
- (FunctionEntry forced_info ident params:repeat ControlEntry)
+ (\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.
--
-- 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
+ 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
+ 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
+ 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)
+ 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
- (Maybe CLabel, -- label in top slot
+ (CmmFormalsWithoutKinds, -- arguments
+ Maybe CLabel, -- label in top slot
[Maybe LocalReg]))] -- slots
- formats = selectStackFormat live continuations
+ 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, [(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.
+ 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 (applyStackFormat (snd formats')) continuations
+ continuations' = map (applyContinuationFormat format_list) 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)
-
---------------------------------------------------------------------------------
-
--- 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).
-
-continuationLabel (Continuation _ l _ _) = l
-data Continuation info =
- Continuation
- info -- 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 StackFormat
- = 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
+ 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
+ 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 ::
-- * 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
+ 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
- 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
+ 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 (CmmNonInfo Nothing)
+ 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
_ -> 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
+ ContinuationEntry args _ _ -> args
+ ControlEntry ->
+ uniqSetToList $
+ lookupWithDefaultUFM live unknown_block start
+ -- it's a proc-point, pass lives in parameter registers
--------------------------------------------------------------------------------
-- For now just select the continuation orders in the order they are in the set with no gaps
-selectStackFormat :: BlockEnv CmmLive
+selectContinuationFormat :: BlockEnv CmmLive
-> [Continuation (Either C_SRT CmmInfo)]
- -> [(CLabel, (Maybe CLabel, [Maybe LocalReg]))]
-selectStackFormat live continuations =
- map (\c -> (continuationLabel c, selectStackFormat' c)) continuations
+ -> [(CLabel, (CmmFormalsWithoutKinds, Maybe CLabel, [Maybe LocalReg]))]
+selectContinuationFormat live continuations =
+ map (\c -> (continuationLabel c, selectContinuationFormat' c)) continuations
where
- selectStackFormat' (Continuation
- (Right (CmmInfo _ _ _ (ContInfo format srt)))
- label _ _) = (Just label, format)
- selectStackFormat' (Continuation (Right _) _ _ _) = (Nothing, [])
- selectStackFormat' (Continuation (Left srt) label _ 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 (Just label,
+ in (formals,
+ Just label,
map Just $ uniqSetToList $
lookupWithDefaultUFM live unknown_block ident)
- unknown_block = panic "unknown BlockId in selectStackFormat"
+ unknown_block = panic "unknown BlockId in selectContinuationFormat"
-processFormats :: [(CLabel, (Maybe CLabel, [Maybe LocalReg]))]
- -> (WordOff, [(CLabel, StackFormat)])
-processFormats formats = (max_size, formats')
+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 = foldl max 0 (map (stack_frame_size . snd) formats')
+ max_size = maximum $
+ 0 : map (continuationMaxStack formats') continuations
formats' = map make_format formats
- make_format (label, format) =
+ make_format (label, (formals, top, stack)) =
(label,
- StackFormat {
- stack_label = fst format,
- stack_frame_size = stack_size (snd format) +
- if isJust (fst format)
+ ContinuationFormat {
+ continuation_formals = formals,
+ continuation_label = top,
+ continuation_frame_size = stack_size stack +
+ if isJust top
then label_size
else 0,
- stack_live = snd format })
+ 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
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
+
-----------------------------------------------------------------------------
-applyStackFormat :: [(CLabel, StackFormat)]
+applyContinuationFormat :: [(CLabel, ContinuationFormat)]
-> 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
+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 = stack_live $ maybe unknown_block id $ lookup label formats
- unknown_block = panic "unknown BlockId in applyStackFormat"
+ format = continuation_stack $ maybe unknown_block id $ lookup label formats
+ unknown_block = panic "unknown BlockId in applyContinuationFormat"
--- User written non-continuation code
-applyStackFormat formats (Continuation (Right info) label formals blocks) =
- Continuation info label formals blocks
+-- 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
-applyStackFormat formats (Continuation (Left srt) label formals blocks) =
- Continuation (CmmInfo prof gc tag (ContInfo (stack_live $ format) srt))
- label formals blocks
+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
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 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
-
-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]
-
- 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*wORD_SIZE),
- CmmReg spLimReg])
- gc_block]
-
--- 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 _)
- (StackFormat cont_id cont_frame_size live_regs)
- = store_live_values ++ set_stack_header where
- -- TODO: only save variables when actually needed
- -- (may be handled by latter pass)
- store_live_values =
- [stack_put spRel (CmmReg (CmmLocal reg)) offset
- | (reg, offset) <- cont_offsets]
- 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).
-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 =
- [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))
+ unknown_block = panic "unknown BlockId in applyContinuationFormat"
projects / ghc-hetmet.git / blobdiff