Morguing dead code

[ghc-hetmet.git] / compiler / cmm / CmmCPSZ.hs

diff --git a/compiler/cmm/CmmCPSZ.hs b/compiler/cmm/CmmCPSZ.hs
index e44e304..8bcadbb 100644 (file)
--- a/compiler/cmm/CmmCPSZ.hs
+++ b/compiler/cmm/CmmCPSZ.hs
@@ -46,19 +46,16 @@ protoCmmCPSZ :: HscEnv -- Compilation env including
              -> (TopSRT, [CmmZ])  -- SRT table and accumulating list of compiled procs
              -> CmmZ              -- Input C-- with Procedures
              -> IO (TopSRT, [CmmZ]) -- Output CPS transformed C--
-protoCmmCPSZ hsc_env (topSRT, rst) (Cmm tops)
-  | not (dopt Opt_TryNewCodeGen (hsc_dflags hsc_env))
-  = return (topSRT, Cmm tops : rst)                -- Only if -fnew-codegen
-  | otherwise
-  = do let dflags = hsc_dflags hsc_env
-        showPass dflags "CPSZ"
-        (cafEnvs, tops) <- liftM unzip $ mapM (cpsTop hsc_env) tops
-        let topCAFEnv = mkTopCAFInfo (concat cafEnvs)
-        (topSRT, tops) <- foldM (toTops hsc_env topCAFEnv) (topSRT, []) tops
-        -- (topSRT, tops) <- foldM (\ z f -> f topCAFEnv z) (topSRT, []) toTops 
-        let cmms = Cmm (reverse (concat tops))
-        dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "Post CPS Cmm" (ppr cmms)
-        return (topSRT, cmms : rst)
+protoCmmCPSZ hsc_env (topSRT, rst) (Cmm tops) =
+  do let dflags = hsc_dflags hsc_env
+     showPass dflags "CPSZ"
+     (cafEnvs, tops) <- liftM unzip $ mapM (cpsTop hsc_env) tops
+     let topCAFEnv = mkTopCAFInfo (concat cafEnvs)
+     (topSRT, tops) <- foldM (toTops hsc_env topCAFEnv) (topSRT, []) tops
+     -- (topSRT, tops) <- foldM (\ z f -> f topCAFEnv z) (topSRT, []) toTops 
+     let cmms = Cmm (reverse (concat tops))
+     dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "Post CPS Cmm" (ppr cmms)
+     return (topSRT, cmms : rst)
 
 {- [Note global fuel]
 ~~~~~~~~~~~~~~~~~~~~~
@@ -84,9 +81,13 @@ cpsTop hsc_env (CmmProc h l args (stackInfo@(entry_off, _), g)) =
        dump Opt_D_dump_cmmz "Pre common block elimination" g
        g <- return $ elimCommonBlocks g
        dump Opt_D_dump_cmmz "Post common block elimination" g
+
+       ----------- Proc points -------------------
        procPoints <- run $ minimalProcPointSet callPPs g
        g <- run $ addProcPointProtocols callPPs procPoints g
        dump Opt_D_dump_cmmz "Post Proc Points Added" g
+
+       ----------- Spills and reloads -------------------
        g     <- 
               -- pprTrace "pre Spills" (ppr g) $
                 dual_rewrite Opt_D_dump_cmmz "spills and reloads"
@@ -101,32 +102,45 @@ cpsTop hsc_env (CmmProc h l args (stackInfo@(entry_off, _), g)) =
                 dual_rewrite Opt_D_dump_cmmz "Dead Assignment Elimination"
                                         (removeDeadAssignmentsAndReloads procPoints) g
                     -- Remove redundant reloads (and any other redundant asst)
+
+       ----------- Debug only: add code to put zero in dead stack slots----
        -- Debugging: stubbing slots on death can cause crashes early
        g <-  
            -- trace "post dead-assign elim" $
             if opt_StubDeadValues then run $ stubSlotsOnDeath g else return g
+
+
+       --------------- Stack layout ----------------
        slotEnv <- run $ liveSlotAnal g
        mbpprTrace "live slot analysis results: " (ppr slotEnv) $ return ()
-       cafEnv <- 
-                -- trace "post liveSlotAnal" $
-                 run $ cafAnal g
-       (cafEnv, slotEnv) <-
-        -- trace "post print cafAnal" $
-          return $ extendEnvsForSafeForeignCalls cafEnv slotEnv g
+       -- cafEnv <- -- trace "post liveSlotAnal" $ run $ cafAnal g
+       -- (cafEnv, slotEnv) <-
+       --  -- trace "post print cafAnal" $
+       --    return $ extendEnvsForSafeForeignCalls cafEnv slotEnv g
+       slotEnv <- return $ extendEnvWithSafeForeignCalls liveSlotTransfers slotEnv g
        mbpprTrace "slotEnv extended for safe foreign calls: " (ppr slotEnv) $ return ()
        let areaMap = layout procPoints slotEnv entry_off g
        mbpprTrace "areaMap" (ppr areaMap) $ return ()
+
+       ------------  Manifest the the stack pointer --------
        g  <- run $ manifestSP areaMap entry_off g
        dump Opt_D_dump_cmmz "after manifestSP" g
        -- UGH... manifestSP can require updates to the procPointMap.
        -- We can probably do something quicker here for the update...
+
+       ------------- Split into separate procedures ------------
        procPointMap  <- run $ procPointAnalysis procPoints g
        dump Opt_D_dump_cmmz "procpoint map" procPointMap
        gs <- run $ splitAtProcPoints l callPPs procPoints procPointMap
                                        (CmmProc h l args (stackInfo, g))
        mapM_ (dump Opt_D_dump_cmmz "after splitting") gs
+
+       ------------- More CAFs and foreign calls ------------
+       cafEnv <- run $ cafAnal g
+       cafEnv <- return $ extendEnvWithSafeForeignCalls cafTransfers cafEnv  g
        let localCAFs = catMaybes $ map (localCAFInfo cafEnv) gs
        mbpprTrace "localCAFs" (ppr localCAFs) $ return ()
+
        gs <- liftM concat $ run $ foldM lowerSafeForeignCalls [] gs
        mapM_ (dump Opt_D_dump_cmmz "after lowerSafeForeignCalls") gs