-----------------------------------------------------------------------------
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--
+ -> IO [GenCmm CmmStatic CmmInfo CmmStmt] -- ^ Output CPS transformed C--
cmmCPS dflags abstractC = do
when (dopt Opt_DoCmmLinting dflags) $
do showPass dflags "CmmLint"
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)],
+ CmmInfo (Just existing) _ _
+ -> (old_info, [], make_gc_check stack_use existing)
+ CmmInfo Nothing update_frame info_table
+ -> (CmmInfo (Just block_id) update_frame info_table,
+ [make_gc_block block_id fun_label formals (CmmSafe $ cmmInfoTableSRT info_table)],
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'
+
+cmmInfoTableSRT CmmNonInfoTable = NoC_SRT
+cmmInfoTableSRT (CmmInfoTable _ _ (ConstrInfo _ _ _)) = NoC_SRT
+cmmInfoTableSRT (CmmInfoTable _ _ (FunInfo _ srt _ _ _ _)) = srt
+cmmInfoTableSRT (CmmInfoTable _ _ (ThunkInfo _ srt)) = srt
+cmmInfoTableSRT (CmmInfoTable _ _ (ThunkSelectorInfo _ srt)) = srt
+cmmInfoTableSRT (CmmInfoTable _ _ (ContInfo _ srt)) = srt
-----------------------------------------------------------------------------
-- |CPS a single CmmTop (proceedure)
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
+ -> [GenCmmTop CmmStatic CmmInfo CmmStmt] -- ^Output proceedure and continuations
+
+-- 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]
+
+-- CPS transform for those procs that actually need it
+cpsProc uniqSupply (CmmProc info ident params blocks) = cps_procs
where
(uniqSupply1, uniqSupply2) = splitUniqSupply uniqSupply
uniques :: [[Unique]]
uniques = map uniqsFromSupply $ listSplitUniqSupply uniqSupply1
- (gc_unique:stack_use_unique:info_uniques):adaptor_uniques:block_uniques = uniques
+ (gc_unique:gc_block_unique:stack_use_unique:info_uniques):adaptor_uniques:block_uniques = uniques
proc_uniques = map (map uniqsFromSupply . listSplitUniqSupply) $ listSplitUniqSupply uniqSupply2
stack_use = CmmLocal (LocalReg stack_use_unique (cmmRegRep spReg) KindPtr)
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
+ gc_block_id = BlockId gc_block_unique
- 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_blocks =
+ BasicBlock gc_block_id
+ (check_stmts++[CmmBranch $ blockId $ head blocks]) :
+ blocks ++ gc_blocks
forced_gc_id = case forced_info of
- CmmNonInfo (Just x) -> x
- CmmInfo _ (Just x) _ _ -> x
+ CmmInfo (Just x) _ _ -> x
+
+ update_frame = case info of CmmInfo _ u _ -> u
-- Break the block at each function call.
-- The part after the function call will have to become a continuation.
-- 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'
- -- 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)
-
-----------------------------------------------------------------------------
collectNonProcPointTargets ::
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
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
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 = 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
-- User written continuations
applyContinuationFormat formats (Continuation
- (Right (CmmInfo prof gc tag (ContInfo _ srt)))
+ (Right (CmmInfo gc update_frame (CmmInfoTable prof tag (ContInfo _ srt))))
label formals is_gc blocks) =
- Continuation (CmmInfo prof gc tag (ContInfo format srt))
+ 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
-- 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 prof tag (ContInfo (continuation_stack $ format) srt)))
label formals is_gc blocks
where
gc = Nothing -- Generated continuations never need a stack check