import Dataflow (fixedpoint)
import CmmLive
+import CmmCPSData
+import CmmProcPoint
import MachOp
import ForeignCall
-- and heap memory (not sure if that's usefull at all though, but it may
-- be worth exploring the design space).
-data BrokenBlock
- = BrokenBlock {
- brokenBlockId :: BlockId, -- Like a CmmBasicBlock
- brokenBlockEntry :: BlockEntryInfo,
- -- How this block can be entered
-
- brokenBlockStmts :: [CmmStmt],
- -- Like a CmmBasicBlock
- -- (but without the last statement)
-
- brokenBlockTargets :: [BlockId],
- -- Blocks that this block could
- -- branch to one either by conditional
- -- branches or via the last statement
-
- brokenBlockExit :: FinalStmt
- -- How the block can be left
- }
-
continuationLabel (Continuation _ _ l _ _) = l
data Continuation =
Continuation
-- to a label. To jump to the first block in a Proc,
-- use the appropriate CLabel.
-data BlockEntryInfo
- = FunctionEntry -- Beginning of a function
- CLabel -- The function name
- CmmFormals -- Aguments to function
-
- | ContinuationEntry -- Return point of a call
- CmmFormals -- return values (argument to continuation)
- -- TODO:
- -- | ProcPointEntry -- no return values, but some live might end up as params or possibly in the frame
-
- | ControlEntry -- A label in the input
-
--- Final statement in a BlokenBlock
--- Constructors and arguments match those in Cmm,
--- but are restricted to branches, returns, jumps, calls and switches
-data FinalStmt
- = FinalBranch
- BlockId -- next block (must be a ControlEntry)
-
- | FinalReturn
- CmmActuals -- return values
-
- | FinalJump
- CmmExpr -- the function to call
- CmmActuals -- arguments to call
-
- | FinalCall
- 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)
-
- | FinalSwitch
- CmmExpr [Maybe BlockId] -- Table branch
-
- -- TODO: | ProcPointExit (needed?)
-
-- Describes the layout of a stack frame for a continuation
data StackFormat
= StackFormat
-- A block can be a continuation of another block (w/ or w/o joins)
-- A block can be an entry to a function
-blocksToBlockEnv :: [BrokenBlock] -> BlockEnv BrokenBlock
-blocksToBlockEnv blocks = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks
-
-----------------------------------------------------------------------------
-calculateOwnership :: UniqSet BlockId -> [BrokenBlock] -> BlockEnv (UniqSet BlockId)
-calculateOwnership proc_points blocks =
- fixedpoint dependants update (map brokenBlockId blocks) emptyUFM
- where
- blocks_ufm :: BlockEnv BrokenBlock
- blocks_ufm = blocksToBlockEnv blocks
-
- dependants :: BlockId -> [BlockId]
- dependants ident =
- brokenBlockTargets $ lookupWithDefaultUFM
- blocks_ufm unknown_block ident
-
- update :: BlockId -> Maybe BlockId
- -> BlockEnv (UniqSet BlockId) -> Maybe (BlockEnv (UniqSet BlockId))
- update ident cause owners =
- case (cause, ident `elementOfUniqSet` proc_points) of
- (Nothing, True) -> Just $ addToUFM owners ident (unitUniqSet ident)
- (Nothing, False) -> Nothing
- (Just cause', True) -> Nothing
- (Just cause', False) ->
- if (sizeUniqSet old) == (sizeUniqSet new)
- then Nothing
- else Just $ addToUFM owners ident new
- where
- old = lookupWithDefaultUFM owners emptyUniqSet ident
- new = old `unionUniqSets` lookupWithDefaultUFM owners emptyUniqSet cause'
-
- unknown_block = panic "unknown BlockId in selectStackFormat"
-
-calculateProcPoints :: [BrokenBlock] -> UniqSet BlockId
-calculateProcPoints blocks = calculateProcPoints' init_proc_points blocks
- where
- init_proc_points = mkUniqSet $
- map brokenBlockId $
- filter always_proc_point blocks
- always_proc_point BrokenBlock {
- brokenBlockEntry = FunctionEntry _ _ } = True
- always_proc_point BrokenBlock {
- brokenBlockEntry = ContinuationEntry _ } = True
- always_proc_point _ = False
-
-calculateProcPoints' :: UniqSet BlockId -> [BrokenBlock] -> UniqSet BlockId
-calculateProcPoints' old_proc_points blocks =
- if sizeUniqSet old_proc_points == sizeUniqSet new_proc_points
- then old_proc_points
- else calculateProcPoints' new_proc_points blocks
- where
- owners = calculateOwnership old_proc_points blocks
- new_proc_points = unionManyUniqSets (old_proc_points:(map (calculateProcPoints'' owners) blocks))
-
-calculateProcPoints'' :: BlockEnv (UniqSet BlockId) -> BrokenBlock -> UniqSet BlockId
-calculateProcPoints'' owners block =
- unionManyUniqSets (map (f parent_id) child_ids)
- where
- parent_id = brokenBlockId block
- child_ids = brokenBlockTargets block
- -- TODO: name for f
- f parent_id child_id =
- if needs_proc_point
- then unitUniqSet child_id
- else emptyUniqSet
- where
- parent_owners = lookupWithDefaultUFM owners emptyUniqSet parent_id
- child_owners = lookupWithDefaultUFM owners emptyUniqSet child_id
- needs_proc_point = not $ isEmptyUniqSet $ child_owners `minusUniqSet` parent_owners
collectNonProcPointTargets ::
UniqSet BlockId -> BlockEnv BrokenBlock
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