+{-# 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 CmmProcPoint
import CmmCallConv
import CmmCPSGen
-import CmmInfo
import CmmUtils
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 CmmInfo 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)
-
-make_gc_check stack_use gc_block =
- [CmmCondBranch
- (CmmMachOp (MO_U_Lt $ cmmRegRep spReg)
- [CmmReg stack_use, CmmReg spLimReg])
- gc_block]
-
-force_gc_block old_info stack_use block_id fun_label formals =
- case old_info of
- CmmNonInfo (Just existing) -> (old_info, [], make_gc_check stack_use existing)
- CmmInfo _ (Just existing) _ _ -> (old_info, [], make_gc_check stack_use existing)
- CmmNonInfo Nothing
- -> (CmmNonInfo (Just block_id),
- [make_gc_block block_id fun_label formals (CmmSafe NoC_SRT)],
- make_gc_check stack_use block_id)
- 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)],
- make_gc_check stack_use block_id)
- 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 CmmInfo CmmStmt] -- ^Output proceedure and continuations
+ -> 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 _ _ _ []) = [proc]
+cpsProc uniqSupply proc@(CmmProc _ _ _ (ListGraph []))
+ = pprTrace "cpsProc: unexpected empty proc" (ppr proc) [proc]
-- CPS transform for those procs that actually need it
-cpsProc uniqSupply (CmmProc info ident params blocks) = cps_procs
+-- 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
- (gc_unique:stack_use_unique:info_uniques):adaptor_uniques:block_uniques = uniques
- proc_uniques = map (map uniqsFromSupply . listSplitUniqSupply) $ listSplitUniqSupply uniqSupply2
+ (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) KindPtr)
+ stack_use = CmmLocal (LocalReg stack_use_unique (cmmRegType spReg))
+ 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)
- -- TODO: doc
- forced_gc :: (CmmInfo, [CmmBasicBlock], [CmmStmt])
- forced_gc = force_gc_block info stack_use (BlockId gc_unique) ident params
- (forced_info, gc_blocks, check_stmts) = forced_gc
+ forced_blocks = stack_check_block : blocks
- forced_blocks =
- case blocks of
- (BasicBlock id stmts) : bs ->
- (BasicBlock id (check_stmts ++ stmts)) : (bs ++ gc_blocks)
- [] -> [] -- If there is no code then we don't need a stack check
-
- 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 :: ([(BlockId, ContFormat)], [BrokenBlock])
broken_blocks =
(\x -> (concatMap fst x, concatMap snd x)) $
- zipWith3 (breakBlock [forced_gc_id])
+ zipWith3 (breakBlock (maybeToList maybe_gc_block_id))
block_uniques
forced_blocks
- (FunctionEntry forced_info ident params :
+ (FunctionEntry info ident params :
repeat ControlEntry)
f' = selectContinuations (fst broken_blocks)
-- Do a little meta-processing on the stack formats such as
-- getting the individual frame sizes and the maximum frame size
- formats' :: (WordOff, [(CLabel, ContinuationFormat)])
- formats' = processFormats formats continuations
+ 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 (snd formats')) continuations
+ 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
+ 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 (typeWidth (cmmRegType 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 ::
new_targets
(map (:[]) targets)
where
- blocks' = map (lookupWithDefaultUFM blocks (panic "TODO")) new_blocks
+ blocks' = map (lookupWithDefaultBEnv 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,
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 (panic "TODO") start
+ start_block = lookupWithDefaultBEnv blocks unknown_block start
+ children_blocks = map (lookupWithDefaultBEnv blocks unknown_block) (uniqSetToList children)
unknown_block = panic "unknown block in gatherBlocksIntoContinuation"
- children_blocks = map (lookupWithDefaultUFM blocks (panic "TODO")) (uniqSetToList children)
body = start_block : children_blocks
-- We can't properly annotate the continuation's stack parameters
info_table = case start_block_entry of
FunctionEntry info _ _ -> Right info
ContinuationEntry _ srt _ -> Left srt
- ControlEntry -> Right (CmmNonInfo Nothing)
+ ControlEntry -> Right (CmmInfo Nothing Nothing CmmNonInfoTable)
is_gc_cont = case start_block_entry of
FunctionEntry _ _ _ -> False
ContinuationEntry args _ _ -> args
ControlEntry ->
uniqSetToList $
- lookupWithDefaultUFM live unknown_block start
+ lookupWithDefaultBEnv live unknown_block start
-- it's a proc-point, pass lives in parameter registers
--------------------------------------------------------------------------------
where
-- User written continuations
selectContinuationFormat' (Continuation
- (Right (CmmInfo _ _ _ (ContInfo format srt)))
+ (Right (CmmInfo _ _ (CmmInfoTable _ _ _ (ContInfo format srt))))
label formals _ _) =
(formals, Just label, format)
-- Either user written non-continuation code
in (formals,
Just label,
map Just $ uniqSetToList $
- lookupWithDefaultUFM live unknown_block ident)
+ lookupWithDefaultBEnv live unknown_block ident)
unknown_block = panic "unknown BlockId in selectContinuationFormat"
processFormats :: [(CLabel, (CmmFormals, Maybe CLabel, [Maybe LocalReg]))]
+ -> Maybe UpdateFrame
-> [Continuation (Either C_SRT CmmInfo)]
- -> (WordOff, [(CLabel, ContinuationFormat)])
-processFormats formats continuations = (max_size, formats')
+ -> (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
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 = (widthInBytes $ typeWidth $ cmmExprType 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 (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
+ width = (widthInBytes $ typeWidth $ localRegType reg) `quot` wORD_SIZE
-- TODO: it would be better if we had a machRepWordWidth
continuationMaxStack :: [(CLabel, ContinuationFormat)]
map stmt_arg_size (brokenBlockStmts block))
final_arg_size (FinalReturn args) =
- argumentsSize (cmmExprRep . fst) args
+ argumentsSize (cmmExprType . hintlessCmm) args
final_arg_size (FinalJump _ args) =
- argumentsSize (cmmExprRep . fst) args
- final_arg_size (FinalCall next _ _ args _ True) = 0
- final_arg_size (FinalCall next _ _ args _ False) =
+ argumentsSize (cmmExprType . hintlessCmm) 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 . fst) args +
+ argumentsSize (cmmExprType . hintlessCmm) args +
continuation_frame_size next_format
where
next_format = maybe unknown_format id $ lookup next' formats
final_arg_size _ = 0
stmt_arg_size (CmmJump _ args) =
- argumentsSize (cmmExprRep . fst) args
- stmt_arg_size (CmmCall _ _ _ (CmmSafe _)) =
+ argumentsSize (cmmExprType . hintlessCmm) args
+ stmt_arg_size (CmmCall _ _ _ (CmmSafe _) _) =
panic "Safe call in processFormats"
stmt_arg_size (CmmReturn _) =
panic "CmmReturn in processFormats"
-> Continuation CmmInfo
-- User written continuations
-applyContinuationFormat formats (Continuation
- (Right (CmmInfo prof gc tag (ContInfo _ srt)))
- label formals is_gc blocks) =
- Continuation (CmmInfo prof gc tag (ContInfo format srt))
+applyContinuationFormat formats
+ (Continuation (Right (CmmInfo gc update_frame
+ (CmmInfoTable clos prof tag (ContInfo _ srt))))
+ label formals is_gc blocks) =
+ Continuation (CmmInfo gc update_frame (CmmInfoTable clos prof tag (ContInfo format srt)))
label formals is_gc blocks
where
format = continuation_stack $ maybe unknown_block id $ lookup label formats
-- CPS generated continuations
applyContinuationFormat formats (Continuation
(Left srt) label formals is_gc blocks) =
- Continuation (CmmInfo prof gc tag (ContInfo (continuation_stack $ format) srt))
+ Continuation (CmmInfo gc Nothing (CmmInfoTable undefined prof tag (ContInfo (continuation_stack $ format) srt)))
label formals is_gc blocks
where
gc = Nothing -- Generated continuations never need a stack check
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