-
-collectNonProcPointTargets ::
- UniqSet BlockId -> BlockEnv BrokenBlock
- -> UniqSet BlockId -> BlockId -> UniqSet BlockId
-collectNonProcPointTargets proc_points blocks current_targets block =
- if sizeUniqSet current_targets == sizeUniqSet new_targets
- then current_targets
- else foldl (collectNonProcPointTargets proc_points blocks) new_targets targets
- where
- block' = lookupWithDefaultUFM blocks (panic "TODO") block
- 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 $ (mkUniqSet $ brokenBlockTargets block') `minusUniqSet` proc_points
- -- TODO: remove redundant uniqSetToList
- new_targets = current_targets `unionUniqSets` (mkUniqSet targets)
-
-procPointToContinuation ::
- UniqSet BlockId -> BlockEnv BrokenBlock
- -> BlockId -> Continuation
-procPointToContinuation proc_points blocks start =
- Continuation is_entry info_table clabel params body
- where
- children = (collectNonProcPointTargets proc_points blocks (unitUniqSet start) start) `delOneFromUniqSet` start
- start_block = lookupWithDefaultUFM blocks (panic "TODO") start
- children_blocks = map (lookupWithDefaultUFM blocks (panic "TODO")) (uniqSetToList children)
- body = start_block : children_blocks
- info_table = [] -- TODO
- start_block_entry = brokenBlockEntry start_block
- is_entry = case start_block_entry of
- FunctionEntry _ _ -> True
- _ -> False
- 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 -> [] -- TODO: it's a proc-point, we could 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 -> [Continuation] -> [(CLabel, StackFormat)]
-selectStackFormat live continuations =
- map (\c -> (continuationLabel c, selectStackFormat' c)) continuations
- where
- selectStackFormat' (Continuation True info_table label formals blocks) =
- --let ident = brokenBlockId $ head blocks -- TODO: CLabel isn't a uniquable, but we need a better way than this
- --in
- StackFormat (Just label) 0 []
- selectStackFormat' (Continuation False info_table 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 live_to_format label formals $ lookupWithDefaultUFM live unknown_block ident
-
- live_to_format :: CLabel -> CmmFormals -> CmmLive -> StackFormat
- live_to_format label formals live =
- foldl extend_format
- (StackFormat (Just label) retAddrSizeW [])
- (uniqSetToList (live `minusUniqSet` mkUniqSet (cmmFormalsToLiveLocals formals)))
-
- extend_format :: StackFormat -> LocalReg -> StackFormat
- extend_format (StackFormat label size offsets) reg =
- StackFormat label (slot_size reg + size) ((CmmLocal reg, size) : offsets)
-
- slot_size :: LocalReg -> Int
- slot_size reg = ((machRepByteWidth (localRegRep reg) - 1) `div` wORD_SIZE) + 1
-
- unknown_block = panic "unknown BlockId in selectStackFormat"
-
-continuationToProc :: [(CLabel, StackFormat)] -> Continuation -> CmmTop
-continuationToProc formats (Continuation is_entry info label formals blocks) =
- CmmProc info label formals (map (continuationToProc' label formats) blocks)
- where
- continuationToProc' :: CLabel -> [(CLabel, StackFormat)] -> BrokenBlock
- -> CmmBasicBlock
- continuationToProc' curr_ident formats (BrokenBlock ident entry stmts _ exit) =
- BasicBlock ident (prefix++stmts++postfix)
- where
- curr_format = maybe unknown_block id $ lookup curr_ident formats
- unknown_block = panic "unknown BlockId in continuationToProc"
- prefix = case entry of
- ControlEntry -> []
- FunctionEntry _ _ -> []
- ContinuationEntry formals ->
- unpack_continuation curr_format
- postfix = case exit of
- FinalBranch next -> [CmmBranch next]
- FinalSwitch expr targets -> [CmmSwitch expr targets]
- FinalReturn arguments ->
- exit_function curr_format
- (CmmLoad (CmmReg spReg) wordRep)
- arguments
- FinalJump target arguments ->
- exit_function curr_format target arguments
- -- TODO: do something about global saves
- FinalCall next (CmmForeignCall target CmmCallConv)
- results arguments saves ->
- pack_continuation curr_format cont_format ++
- [CmmJump target arguments]
- where
- cont_format = maybe unknown_block id $
- lookup (mkReturnPtLabel $ getUnique next) formats
- FinalCall next _ results arguments saves -> panic "unimplemented CmmCall"
-
---------------------------------------------------------------------------------
--- 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 =
- if curr_frame_size == 0
- then []
- else [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]
- needs_header =
- case (curr_id, cont_id) of
- (Just x, Just y) -> x /= y
- _ -> isJust cont_id
- set_stack_header =
- if not needs_header
- then []
- else [CmmStore (CmmRegOff spReg (wORD_SIZE*(curr_frame_size - cont_frame_size))) continuation_function]
- continuation_function = CmmLit $ CmmLabel $ fromJust 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]
-
------------------------------------------------------------------------------
--- Breaking basic blocks on function calls
------------------------------------------------------------------------------
-
------------------------------------------------------------------------------
--- Takes a basic block and breaks it up into a list of broken blocks
---
--- 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.
-
-breakBlock :: [Unique] -> CmmBasicBlock -> BlockEntryInfo -> [BrokenBlock]
-breakBlock uniques (BasicBlock ident stmts) entry =
- breakBlock' uniques ident entry [] [] stmts where
- breakBlock' uniques current_id entry exits accum_stmts stmts =
- case stmts of
- [] -> panic "block doesn't end in jump, goto or return"
- [CmmJump target arguments] ->
- [BrokenBlock current_id entry accum_stmts
- exits
- (FinalJump target arguments)]
- [CmmReturn arguments] ->
- [BrokenBlock current_id entry accum_stmts
- exits
- (FinalReturn arguments)]
- [CmmBranch target] ->
- [BrokenBlock current_id entry accum_stmts
- (target:exits)
- (FinalBranch target)]
- [CmmSwitch expr targets] ->
- [BrokenBlock current_id entry accum_stmts
- (mapMaybe id targets ++ exits)
- (FinalSwitch expr targets)]
- (CmmJump _ _:_) ->
- panic "jump in middle of block"
- (CmmReturn _:_) ->
- panic "return in middle of block"
- (CmmBranch _:_) ->
- panic "branch in middle of block"
- (CmmSwitch _ _:_) ->
- panic ("switch in middle of block" ++ (showSDoc $ ppr stmts))
- (CmmCall target results arguments saves:stmts) -> block : rest
- where
- new_id = BlockId $ head uniques
- block = BrokenBlock current_id entry accum_stmts
- (new_id:exits)
- (FinalCall new_id target results arguments saves)
- rest = breakBlock' (tail uniques) new_id
- (ContinuationEntry results) [] [] stmts
- (s@(CmmCondBranch test target):stmts) ->
- breakBlock' uniques current_id entry
- (target:exits) (accum_stmts++[s]) stmts
- (s:stmts) ->
- breakBlock' uniques current_id entry
- exits (accum_stmts++[s]) stmts
-
---------------------------------
--- Convert from a BrokenBlock
--- to a CmmBasicBlock so the
--- liveness analysis can run
--- on it.
---------------------------------
-cmmBlockFromBrokenBlock :: BrokenBlock -> CmmBasicBlock
-cmmBlockFromBrokenBlock (BrokenBlock ident _ stmts _ exit) =
- BasicBlock ident (stmts++exit_stmt)
- where
- exit_stmt =
- case exit of
- FinalBranch target -> [CmmBranch target]
- FinalReturn arguments -> [CmmReturn arguments]
- FinalJump target arguments -> [CmmJump target arguments]
- FinalSwitch expr targets -> [CmmSwitch expr targets]
- FinalCall branch_target call_target results arguments saves ->
- [CmmCall call_target results arguments saves,
- CmmBranch branch_target]
-
------------------------------------------------------------------------------
--- CPS a single CmmTop (proceedure)