X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmCPS.hs;h=2726ef83041d3e84bef53fc7fe54a107bba3499c;hb=bdfa9495e95ba5701f27711b27d8e22ae7bb8335;hp=b00a50fb069c62031c38dd446f0f547fe2829181;hpb=8bae799da7444d5debe0ce2e3f3f73692991a59d;p=ghc-hetmet.git diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index b00a50f..2726ef8 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -10,10 +10,11 @@ import Cmm import CmmLint import PprCmm -import Dataflow (fixedpoint) +import Dataflow import CmmLive import CmmBrokenBlock import CmmProcPoint +import CmmCallConv import MachOp import ForeignCall @@ -34,6 +35,90 @@ import Monad import IO import Data.List +----------------------------------------------------------------------------- +-- |Top level driver for the CPS pass +----------------------------------------------------------------------------- +cmmCPS :: DynFlags -- ^ Dynamic flags: -dcmm-lint -ddump-cps-cmm + -> [Cmm] -- ^ Input C-- with Proceedures + -> IO [Cmm] -- ^ 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" + + -- 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 + + dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC) + + -- TODO: add option to dump Cmm to file + + return continuationC + +----------------------------------------------------------------------------- +-- |CPS a single CmmTop (proceedure) +-- Only 'CmmProc' are transformed 'CmmData' will be left alone. +----------------------------------------------------------------------------- + +cpsProc :: UniqSupply + -> CmmTop -- ^Input proceedure + -> [CmmTop] -- ^Output proceedure and continuations +cpsProc uniqSupply x@(CmmData _ _) = [x] +cpsProc uniqSupply x@(CmmProc info_table ident params blocks) = cps_procs + where + uniqes :: [[Unique]] + uniqes = map uniqsFromSupply $ listSplitUniqSupply uniqSupply + + -- Break the block at each function call. + -- The part after the function call will have to become a continuation. + broken_blocks :: [BrokenBlock] + broken_blocks = + concat $ zipWith3 breakBlock uniqes blocks + (FunctionEntry ident params:repeat ControlEntry) + + -- Calculate live variables for each broken block. + -- + -- Nothing can be live on entry to the first 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 + + -- Calculate which blocks must be made into full fledged procedures. + proc_points :: UniqSet BlockId + 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 + + -- Group the blocks into continuations based on the set of proc-points. + continuations :: [Continuation] + continuations = map (gatherBlocksIntoContinuation proc_points block_env) + (uniqSetToList proc_points) + + -- Select the stack format on entry to each continuation. + -- + -- This is an association list instead of a UniqFM because + -- CLabel's don't have a 'Uniqueable' instance. + formats :: [(CLabel, StackFormat)] + formats = selectStackFormat live continuations + + -- Do the actual CPS transform. + cps_procs :: [CmmTop] + cps_procs = map (continuationToProc formats) continuations + -------------------------------------------------------------------------------- -- The format for the call to a continuation @@ -97,10 +182,15 @@ collectNonProcPointTargets proc_points blocks current_targets block = -- TODO: remove redundant uniqSetToList new_targets = current_targets `unionUniqSets` (mkUniqSet targets) -procPointToContinuation :: +-- TODO: insert proc point code here +-- * Branches and switches to proc points may cause new blocks to be created +-- (or proc points could leave behind phantom blocks that just jump to them) +-- * Proc points might get some live variables passed as arguments + +gatherBlocksIntoContinuation :: UniqSet BlockId -> BlockEnv BrokenBlock -> BlockId -> Continuation -procPointToContinuation proc_points blocks start = +gatherBlocksIntoContinuation proc_points blocks start = Continuation is_entry info_table clabel params body where children = (collectNonProcPointTargets proc_points blocks (unitUniqSet start) start) `delOneFromUniqSet` start @@ -128,8 +218,6 @@ 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 @@ -176,15 +264,14 @@ continuationToProc formats (Continuation is_entry info label formals blocks) = arguments FinalJump target arguments -> exit_function curr_format target arguments - -- TODO: do something about global saves FinalCall next (CmmForeignCall target CmmCallConv) - results arguments saves -> + results arguments -> 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" + FinalCall next _ results arguments -> panic "unimplemented CmmCall" -------------------------------------------------------------------------------- -- Functions that generate CmmStmt sequences @@ -209,7 +296,7 @@ enter_function max_frame_size (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 + gc_block = panic "gc_check not implemented" -- 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] @@ -251,144 +338,3 @@ unpack_continuation (StackFormat curr_id curr_frame_size curr_offsets) (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) ------------------------------------------------------------------------------ - -cpsProc :: UniqSupply -> CmmTop -> [CmmTop] -cpsProc uniqSupply x@(CmmData _ _) = [x] -cpsProc uniqSupply x@(CmmProc info_table ident params blocks) = cps_procs - where - uniqes :: [[Unique]] - uniqes = map uniqsFromSupply $ listSplitUniqSupply uniqSupply - - -- Break the block at each function call - broken_blocks :: [BrokenBlock] - broken_blocks = concat $ zipWith3 breakBlock uniqes blocks - (FunctionEntry ident params:repeat ControlEntry) - - -- Calculate live variables for each broken block - live :: BlockEntryLiveness - live = cmmLiveness $ map cmmBlockFromBrokenBlock broken_blocks - -- nothing can be live on entry to the first block so we could take the tail - - proc_points :: UniqSet BlockId - proc_points = calculateProcPoints broken_blocks - - -- TODO: insert proc point code here - -- * Branches and switches to proc points may cause new blocks to be created - -- (or proc points could leave behind phantom blocks that just jump to them) - -- * Proc points might get some live variables passed as arguments - - continuations :: [Continuation] - continuations = map (procPointToContinuation proc_points (blocksToBlockEnv broken_blocks)) (uniqSetToList proc_points) - - -- Select the stack format on entry to each block - formats :: [(CLabel, StackFormat)] - formats = selectStackFormat live continuations - - -- Do the actual CPS transform - cps_procs :: [CmmTop] - cps_procs = map (continuationToProc formats) continuations - --------------------------------------------------------------------------------- -cmmCPS :: DynFlags - -> [Cmm] -- C-- with Proceedures - -> IO [Cmm] -- 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" - -- TODO: check for use of branches to non-existant blocks - -- TODO: check for use of Sp, SpLim, R1, R2, etc. - -- TODO: find out if it is valid to create a new unique source like this - uniqSupply <- mkSplitUniqSupply 'p' - let supplies = listSplitUniqSupply uniqSupply - let continuationC = zipWith (\s (Cmm c) -> Cmm $ concat $ zipWith (cpsProc) (listSplitUniqSupply s) c) supplies abstractC - - dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC) - -- TODO: add option to dump Cmm to file - return continuationC