CmmPipeline.hs 9.72 KB
Newer Older
1 2 3
{-# OPTIONS_GHC -XNoMonoLocalBinds #-}
-- Norman likes local bindings
-- If this module lives on I'd like to get rid of this flag in due course
4

Edward Z. Yang's avatar
Edward Z. Yang committed
5
module CmmPipeline (
6 7 8 9
  -- | Converts C-- with an implicit stack and native C-- calls into
  -- optimized, CPS converted and native-call-less C--.  The latter
  -- C-- can be used to generate assembly.
  cmmPipeline
10
) where
11

12
import CLabel
13
import Cmm
Simon Marlow's avatar
Simon Marlow committed
14
import CmmLint
15
import CmmLive
16 17
import CmmBuildInfoTables
import CmmCommonBlockElim
18
import CmmProcPoint
19
import CmmSpillReload
20
import CmmRewriteAssignments
21
import CmmStackLayout
22
import CmmContFlowOpt
23
import OptimizationFuel
Simon Marlow's avatar
Simon Marlow committed
24
import CmmLayoutStack
25 26 27

import DynFlags
import ErrUtils
28 29
import HscTypes
import Data.Maybe
Ian Lynagh's avatar
Ian Lynagh committed
30
import Control.Monad
31 32
import Data.Map (Map)
import qualified Data.Map as Map
33 34
import Data.Set (Set)
import qualified Data.Set as Set
35 36
import Outputable
import StaticFlags
37

38
-----------------------------------------------------------------------------
39
-- | Top level driver for C-- pipeline
40
-----------------------------------------------------------------------------
41 42 43 44 45 46 47 48 49 50 51 52 53
-- There are two complications here:
-- 1. We need to compile the procedures in two stages because we need
--    an analysis of the procedures to tell us what CAFs they use.
--    The first stage returns a map from procedure labels to CAFs,
--    along with a closure that will compute SRTs and attach them to
--    the compiled procedures.
--    The second stage is to combine the CAF information into a top-level
--    CAF environment mapping non-static closures to the CAFs they keep live,
--    then pass that environment to the closures returned in the first
--    stage of compilation.
-- 2. We need to thread the module's SRT around when the SRT tables
--    are computed for each procedure.
--    The SRT needs to be threaded because it is grown lazily.
54 55 56 57 58
-- 3. We run control flow optimizations twice, once before any pipeline
--    work is done, and once again at the very end on all of the
--    resulting C-- blocks.  EZY: It's unclear whether or not whether
--    we actually need to do the initial pass.
cmmPipeline  :: HscEnv -- Compilation env including
59
                       -- dynamic flags: -dcmm-lint -ddump-cps-cmm
60
             -> TopSRT     -- SRT table and accumulating list of compiled procs
Simon Peyton Jones's avatar
Simon Peyton Jones committed
61
             -> CmmGroup             -- Input C-- with Procedures
62 63
             -> IO (TopSRT, CmmGroup) -- Output CPS transformed C--
cmmPipeline hsc_env topSRT prog =
64
  do let dflags = hsc_dflags hsc_env
65
     --
66
     showPass dflags "CPSZ"
67

68
     (cafEnvs, tops) <- liftM unzip $ mapM (cpsTop hsc_env) prog
Simon Peyton Jones's avatar
Simon Peyton Jones committed
69
     -- tops :: [[(CmmDecl,CAFSet]]  (one list per group)
70

71
     let topCAFEnv = mkTopCAFInfo (concat cafEnvs)
72 73

     -- folding over the groups
74
     (topSRT, tops) <- foldM (toTops hsc_env topCAFEnv) (topSRT, []) tops
75

76 77
     let cmms :: CmmGroup
         cmms = reverse (concat tops)
78

79
     dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "Post CPS Cmm" (pprPlatform (targetPlatform dflags) cmms)
80

81
     return (topSRT, cmms)
82 83 84 85 86 87 88 89

{- [Note global fuel]
~~~~~~~~~~~~~~~~~~~~~
The identity and the last pass are stored in
mutable reference cells in an 'HscEnv' and are
global to one compiler session.
-}

90 91 92 93
-- EZY: It might be helpful to have an easy way of dumping the "pre"
-- input for any given phase, besides just turning it all on with
-- -ddump-cmmz

Simon Peyton Jones's avatar
Simon Peyton Jones committed
94
cpsTop :: HscEnv -> CmmDecl -> IO ([(CLabel, CAFSet)], [(CAFSet, CmmDecl)])
95
cpsTop _ p@(CmmData {}) = return ([], [(Set.empty, p)])
96 97
cpsTop hsc_env (CmmProc h@(TopInfo {stack_info=StackInfo {arg_space=entry_off}}) l g) =
    do
98 99
       -- Why bother doing these early: dualLivenessWithInsertion,
       -- insertLateReloads, rewriteAssignments?
100

101
       ----------- Control-flow optimisations ---------------
Simon Marlow's avatar
Simon Marlow committed
102
       g <- {-# SCC "cmmCfgOpts(1)" #-} return $ cmmCfgOpts g
103 104
       dump Opt_D_dump_cmmz_cfg "Post control-flow optimsations" g

105
       ----------- Eliminate common blocks -------------------
Simon Marlow's avatar
Simon Marlow committed
106
       g <- {-# SCC "elimCommonBlocks" #-} return $ elimCommonBlocks g
107 108 109
       dump Opt_D_dump_cmmz_cbe "Post common block elimination" g
       -- Any work storing block Labels must be performed _after_
       -- elimCommonBlocks
110 111

       ----------- Proc points -------------------
Simon Marlow's avatar
Simon Marlow committed
112 113
       let callPPs = {-# SCC "callProcPoints" #-} callProcPoints g
       procPoints <- {-# SCC "minimalProcPointSet" #-} run $ minimalProcPointSet (targetPlatform dflags) callPPs g
114

Simon Marlow's avatar
Simon Marlow committed
115 116 117 118 119 120 121 122 123 124 125 126 127 128
       g <- {-# SCC "layoutStack" #-} run $ cmmLayoutStack procPoints entry_off g
       dump Opt_D_dump_cmmz_sp "Layout Stack" g

--       g <- {-# SCC "addProcPointProtocols" #-} run $ addProcPointProtocols callPPs procPoints g
--       dump Opt_D_dump_cmmz_proc "Post Proc Points Added" g
--
--       ----------- Spills and reloads -------------------
--       g <- {-# SCC "dualLivenessWithInsertion" #-} run $ dualLivenessWithInsertion procPoints g
--       dump Opt_D_dump_cmmz_spills "Post spills and reloads" g
--
--       ----------- Sink and inline assignments -------------------
--       g <- {-# SCC "rewriteAssignments" #-} runOptimization $ rewriteAssignments platform g
--       dump Opt_D_dump_cmmz_rewrite "Post rewrite assignments" g
--
129 130

       ----------- Eliminate dead assignments -------------------
Simon Marlow's avatar
Simon Marlow committed
131
       g <- {-# SCC "removeDeadAssignments" #-} runOptimization $ removeDeadAssignments g
132
       dump Opt_D_dump_cmmz_dead "Post remove dead assignments" g
133

Simon Marlow's avatar
Simon Marlow committed
134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152
--       ----------- Zero dead stack slots (Debug only) ---------------
--       -- Debugging: stubbing slots on death can cause crashes early
--       g <- if opt_StubDeadValues
--                then {-# SCC "stubSlotsOnDeath" #-} run $ stubSlotsOnDeath g
--                else return g
--       dump Opt_D_dump_cmmz_stub "Post stub dead stack slots" g
--
--       --------------- Stack layout ----------------
--       slotEnv <- {-# SCC "liveSlotAnal" #-} run $ liveSlotAnal g
--       let spEntryMap = getSpEntryMap entry_off g
--       mbpprTrace "live slot analysis results: " (ppr slotEnv) $ return ()
--       let areaMap = {-# SCC "layout" #-} layout procPoints spEntryMap slotEnv entry_off g
--       mbpprTrace "areaMap" (ppr areaMap) $ return ()
--
--       ------------  Manifest the stack pointer --------
--       g  <- {-# SCC "manifestSP" #-} run $ manifestSP spEntryMap areaMap entry_off g
--       dump Opt_D_dump_cmmz_sp "Post manifestSP" g
--       -- UGH... manifestSP can require updates to the procPointMap.
--       -- We can probably do something quicker here for the update...
153 154

       ------------- Split into separate procedures ------------
Simon Marlow's avatar
Simon Marlow committed
155 156 157
       procPointMap  <- {-# SCC "procPointAnalysis" #-} run $ procPointAnalysis procPoints g
       dumpWith dflags ppr Opt_D_dump_cmmz_procmap "procpoint map" procPointMap
       gs <- {-# SCC "splitAtProcPoints" #-} run $ splitAtProcPoints l callPPs procPoints procPointMap
158
                                       (CmmProc h l g)
Simon Marlow's avatar
Simon Marlow committed
159
       dumps Opt_D_dump_cmmz_split "Post splitting" gs
160 161

       ------------- More CAFs and foreign calls ------------
Simon Marlow's avatar
Simon Marlow committed
162
       cafEnv <- {-# SCC "cafAnal" #-} run $ cafAnal platform g
163 164
       let localCAFs = catMaybes $ map (localCAFInfo platform cafEnv) gs
       mbpprTrace "localCAFs" (pprPlatform platform localCAFs) $ return ()
165

Simon Marlow's avatar
Simon Marlow committed
166 167
--       gs <- {-# SCC "lowerSafeForeignCalls" #-} run $ mapM (lowerSafeForeignCalls areaMap) gs
--       dumps Opt_D_dump_cmmz_lower "Post lowerSafeForeignCalls" gs
168

169
       -- NO MORE GRAPH TRANSFORMATION AFTER HERE -- JUST MAKING INFOTABLES
Simon Marlow's avatar
Simon Marlow committed
170 171
--       gs <- {-# SCC "setInfoTableStackMap" #-} return $ map (setInfoTableStackMap slotEnv areaMap) gs
--       dumps Opt_D_dump_cmmz_info "after setInfoTableStackMap" gs
172

173
       ----------- Control-flow optimisations ---------------
Simon Marlow's avatar
Simon Marlow committed
174 175
       gs <- {-# SCC "cmmCfgOpts(2)" #-} return $ map cmmCfgOptsProc gs
       dumps Opt_D_dump_cmmz_cfg "Post control-flow optimsations" gs
176

Simon Marlow's avatar
Simon Marlow committed
177 178
       gs <- {-# SCC "bundleCAFs" #-} return $ map (bundleCAFs cafEnv) gs
       dumps Opt_D_dump_cmmz_cafs "after bundleCAFs" gs
179

180
       return (localCAFs, gs)
181

Simon Peyton Jones's avatar
Simon Peyton Jones committed
182
              -- gs        :: [ (CAFSet, CmmDecl) ]
183 184
              -- localCAFs :: [ (CLabel, CAFSet) ] -- statics filtered out(?)

185
  where dflags = hsc_dflags hsc_env
Simon Marlow's avatar
Simon Marlow committed
186 187 188
        platform = targetPlatform dflags
        mbpprTrace x y z | dopt Opt_D_dump_cmmz dflags = pprTrace x y z
                         | otherwise = z
189 190
        dump = dumpGraph dflags

Simon Marlow's avatar
Simon Marlow committed
191 192 193
        dumps flag name
           = mapM_ (dumpWith dflags (pprPlatform platform) flag name)

194 195 196 197 198 199
        -- Runs a required transformation/analysis
        run = runInfiniteFuelIO (hsc_OptFuel hsc_env)
        -- Runs an optional transformation/analysis (and should
        -- thus be subject to optimization fuel)
        runOptimization = runFuelIO (hsc_OptFuel hsc_env)

200

Simon Marlow's avatar
Simon Marlow committed
201 202
dumpGraph :: DynFlags -> DynFlag -> String -> CmmGraph -> IO ()
dumpGraph dflags flag name g = do
203
  cmmLint g
Simon Marlow's avatar
Simon Marlow committed
204 205 206 207 208 209 210 211 212 213
  dumpWith dflags (pprPlatform (targetPlatform dflags)) flag name g

dumpWith :: DynFlags -> (a -> SDoc) -> DynFlag -> String -> a -> IO ()
dumpWith dflags pprFun flag txt g = do
         -- ToDo: No easy way of say "dump all the cmmz, *and* split
         -- them into files."  Also, -ddump-cmmz doesn't play nicely
         -- with -ddump-to-file, since the headers get omitted.
   dumpIfSet_dyn dflags flag txt (pprFun g)
   when (not (dopt flag dflags)) $
      dumpIfSet_dyn dflags Opt_D_dump_cmmz txt (pprFun g)
214

215 216 217
-- This probably belongs in CmmBuildInfoTables?
-- We're just finishing the job here: once we know what CAFs are defined
-- in non-static closures, we can build the SRTs.
Simon Peyton Jones's avatar
Simon Peyton Jones committed
218 219
toTops :: HscEnv -> Map CLabel CAFSet -> (TopSRT, [[CmmDecl]])
                 -> [(CAFSet, CmmDecl)] -> IO (TopSRT, [[CmmDecl]])
220 221 222 223 224 225
toTops hsc_env topCAFEnv (topSRT, tops) gs =
  do let setSRT (topSRT, rst) g =
           do (topSRT, gs) <- setInfoTableSRT topCAFEnv topSRT g
              return (topSRT, gs : rst)
     (topSRT, gs') <- runFuelIO (hsc_OptFuel hsc_env) $ foldM setSRT (topSRT, []) gs
     return (topSRT, concat gs' : tops)