From 21bc3ec7555c996ce3a5d8a620831e7758f5f7e9 Mon Sep 17 00:00:00 2001 From: "Michael D. Adams" Date: Fri, 25 May 2007 17:08:45 +0000 Subject: [PATCH] Formatting changes for CPS code. --- compiler/cmm/CmmCPS.hs | 234 ++++++++++++++++++----------------------------- compiler/cmm/CmmLive.hs | 98 ++++++++++---------- 2 files changed, 138 insertions(+), 194 deletions(-) diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index b00a50f..0fe63a7 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -34,6 +34,90 @@ 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 +181,15 @@ 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 @@ -251,144 +340,3 @@ 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 diff --git a/compiler/cmm/CmmLive.hs b/compiler/cmm/CmmLive.hs index 8d13505..8591aae 100644 --- a/compiler/cmm/CmmLive.hs +++ b/compiler/cmm/CmmLive.hs @@ -1,7 +1,8 @@ module CmmLive ( - CmmLive, BlockEntryLiveness, + CmmLive, + BlockEntryLiveness, cmmLiveness, - cmmFormalsToLiveLocals + cmmFormalsToLiveLocals, ) where #include "HsVersions.h" @@ -14,20 +15,24 @@ import Panic import UniqFM import UniqSet -import Data.List - ----------------------------------------------------------------------------- -- Calculating what variables are live on entry to a basic block ----------------------------------------------------------------------------- --- The variables live on entry to a block +-- | The variables live on entry to a block type CmmLive = UniqSet LocalReg --- A mapping from block labels to the variables live on entry +-- | A mapping from block labels to the variables live on entry type BlockEntryLiveness = BlockEnv CmmLive +-- | A mapping from block labels to the blocks that target it +type BlockSources = BlockEnv (UniqSet BlockId) + +-- | A mapping from block labels to the statements in the block +type BlockStmts = BlockEnv [CmmStmt] + ----------------------------------------------------------------------------- --- cmmLiveness and helpers +-- | Calculated liveness info for a list of 'CmmBasicBlock' ----------------------------------------------------------------------------- cmmLiveness :: [CmmBasicBlock] -> BlockEntryLiveness cmmLiveness blocks = @@ -36,8 +41,14 @@ cmmLiveness blocks = (map blockId blocks) (listToUFM [(blockId b, emptyUniqSet) | b <- blocks]) where + sources :: BlockSources sources = cmmBlockSources blocks - blocks' = cmmBlockNames blocks + + blocks' :: BlockStmts + blocks' = listToUFM $ map block_name blocks + + block_name :: CmmBasicBlock -> (BlockId, [CmmStmt]) + block_name b = (blockId b, blockStmts b) {- -- For debugging, annotate each block with a comment indicating @@ -51,27 +62,24 @@ cmmLivenessComment live (BasicBlock ident stmts) = -} --------------------------------- --- cmmBlockSources --- --- Calculates a table of blocks --- that might need updating after --- a given block is updated --------------------------------- -cmmBlockSources :: [CmmBasicBlock] -> BlockEnv (UniqSet BlockId) +----------------------------------------------------------------------------- +-- | Calculates a table of where one can lookup the blocks that might +-- need updating after a given block is updated in the liveness analysis +----------------------------------------------------------------------------- +cmmBlockSources :: [CmmBasicBlock] -> BlockSources cmmBlockSources blocks = foldr aux emptyUFM blocks where aux :: CmmBasicBlock - -> BlockEnv (UniqSet BlockId) - -> BlockEnv (UniqSet BlockId) + -> BlockSources + -> BlockSources aux block sourcesUFM = foldUniqSet (add_source_edges $ blockId block) sourcesUFM (branch_targets $ blockStmts block) add_source_edges :: BlockId -> BlockId - -> BlockEnv (UniqSet BlockId) - -> BlockEnv (UniqSet BlockId) + -> BlockSources + -> BlockSources add_source_edges source target ufm = addToUFM_Acc (flip addOneToUniqSet) unitUniqSet ufm target source @@ -83,40 +91,22 @@ cmmBlockSources blocks = foldr aux emptyUFM blocks target (CmmSwitch _ blocks) = mapMaybe id blocks target _ = [] --------------------------------- --- cmmBlockNames --- --- Calculates a table that maps --- block names to the list --- of statements inside them --------------------------------- -cmmBlockNames :: [CmmBasicBlock] -> BlockEnv [CmmStmt] -cmmBlockNames blocks = listToUFM $ map block_name blocks where - block_name b = (blockId b, blockStmts b) - --------------------------------- --- cmmBlockDependants +----------------------------------------------------------------------------- +-- | Given the table calculated by 'cmmBlockSources', list all blocks +-- that depend on the result of a particular block. -- --- Given the table calculated --- by cmmBlockSources created, --- list all blocks that depend --- on the result of a particular --- block. --------------------------------- -cmmBlockDependants :: BlockEnv (UniqSet BlockId) -> BlockId -> [BlockId] +-- Used by the call to 'fixedpoint'. +----------------------------------------------------------------------------- +cmmBlockDependants :: BlockSources -> BlockId -> [BlockId] cmmBlockDependants sources ident = uniqSetToList $ lookupWithDefaultUFM sources emptyUniqSet ident --------------------------------- --- cmmBlockUpdate --- --- Given the table from --- cmmBlockNames and a block --- that was updated, calculate --- an updated BlockEntryLiveness --------------------------------- +----------------------------------------------------------------------------- +-- | Given the table of type 'BlockStmts' and a block that was updated, +-- calculate an updated BlockEntryLiveness +----------------------------------------------------------------------------- cmmBlockUpdate :: - BlockEnv [CmmStmt] + BlockStmts -> BlockId -> Maybe BlockId -> BlockEntryLiveness @@ -126,13 +116,19 @@ cmmBlockUpdate blocks node _ state = then Nothing else Just $ addToUFM state node new_live where - new_live = cmmStmtListLive state block + new_live, old_live :: CmmLive + new_live = cmmStmtListLive state block_stmts old_live = lookupWithDefaultUFM state missing_live node - block = lookupWithDefaultUFM blocks missing_block node + + block_stmts :: [CmmStmt] + block_stmts = lookupWithDefaultUFM blocks missing_block node + missing_live = panic "unknown block id during liveness analysis" missing_block = panic "unknown block id during liveness analysis" ----------------------------------------------------------------------------- +-- Section: +----------------------------------------------------------------------------- -- CmmBlockLive, cmmStmtListLive and helpers ----------------------------------------------------------------------------- -- 1.7.10.4