Remove the (very) old strictness analyser

[ghc-hetmet.git] / compiler / simplCore / SimplCore.lhs

diff --git a/compiler/simplCore/SimplCore.lhs b/compiler/simplCore/SimplCore.lhs
index 27ada80..beb1ed0 100644 (file)
--- a/compiler/simplCore/SimplCore.lhs
+++ b/compiler/simplCore/SimplCore.lhs
@@ -19,6 +19,7 @@ import DynFlags               ( CoreToDo(..), SimplifierSwitch(..),
                          SimplifierMode(..), DynFlags, DynFlag(..), dopt,
                          getCoreToDo, shouldDumpSimplPhase )
 import CoreSyn
                          SimplifierMode(..), DynFlags, DynFlag(..), dopt,
                          getCoreToDo, shouldDumpSimplPhase )
 import CoreSyn

+import CoreSubst

 import HscTypes
 import CSE             ( cseProgram )
 import Rules           ( RuleBase, emptyRuleBase, mkRuleBase, unionRuleBase,
 import HscTypes
 import CSE             ( cseProgram )
 import Rules           ( RuleBase, emptyRuleBase, mkRuleBase, unionRuleBase,

@@ -27,25 +28,24 @@ import Rules                ( RuleBase, emptyRuleBase, mkRuleBase, unionRuleBase,
                          addSpecInfo, addIdSpecialisations )
 import PprCore         ( pprCoreBindings, pprCoreExpr, pprRules )
 import OccurAnal       ( occurAnalysePgm, occurAnalyseExpr )
                          addSpecInfo, addIdSpecialisations )
 import PprCore         ( pprCoreBindings, pprCoreExpr, pprRules )
 import OccurAnal       ( occurAnalysePgm, occurAnalyseExpr )

-import IdInfo          ( setNewStrictnessInfo, newStrictnessInfo, 
-                         setUnfoldingInfo, unfoldingInfo, setSpecInfoHead,
-                         setInlinePragInfo, inlinePragInfo,
-                         setSpecInfo, specInfo, specInfoRules )
+import IdInfo

 import CoreUtils       ( coreBindsSize )
 import Simplify                ( simplTopBinds, simplExpr )
 import CoreUtils       ( coreBindsSize )
 import Simplify                ( simplTopBinds, simplExpr )

-import SimplEnv                ( SimplEnv, simplBinders, mkSimplEnv, setInScopeSet )
+import SimplUtils      ( simplEnvForGHCi, simplEnvForRules )
+import SimplEnv

 import SimplMonad
 import CoreMonad
 import SimplMonad
 import CoreMonad

-import qualified ErrUtils as Err        ( dumpIfSet_dyn, dumpIfSet, showPass )
-import CoreLint                ( showPass, endPass, endPassIf, endIteration )
+import qualified ErrUtils as Err 
+import CoreLint
+import CoreMonad       ( endPass )

 import FloatIn         ( floatInwards )
 import FloatOut                ( floatOutwards )
 import FamInstEnv
 import Id
 import DataCon
 import FloatIn         ( floatInwards )
 import FloatOut                ( floatOutwards )
 import FamInstEnv
 import Id
 import DataCon

-import TyCon           ( tyConSelIds, tyConDataCons )
+import TyCon           ( tyConDataCons )

 import Class           ( classSelIds )
 import Class           ( classSelIds )

-import BasicTypes       ( CompilerPhase, isActive )
+import BasicTypes       ( CompilerPhase, isActive, isDefaultInlinePragma )

 import VarSet
 import VarEnv
 import NameEnv         ( lookupNameEnv )
 import VarSet
 import VarEnv
 import NameEnv         ( lookupNameEnv )

@@ -55,19 +55,15 @@ import Specialise   ( specProgram)
 import SpecConstr      ( specConstrProgram)
 import DmdAnal         ( dmdAnalPgm )
 import WorkWrap                ( wwTopBinds )
 import SpecConstr      ( specConstrProgram)
 import DmdAnal         ( dmdAnalPgm )
 import WorkWrap                ( wwTopBinds )

-#ifdef OLD_STRICTNESS
-import StrictAnal      ( saBinds )
-import CprAnalyse       ( cprAnalyse )
-#endif

 import Vectorise        ( vectorise )
 import FastString
 import Util
 
 import UniqSupply      ( UniqSupply, mkSplitUniqSupply, splitUniqSupply )
 import Vectorise        ( vectorise )
 import FastString
 import Util
 
 import UniqSupply      ( UniqSupply, mkSplitUniqSupply, splitUniqSupply )

-import IO              ( hPutStr, stderr )

 import Outputable
 import Control.Monad
 import Outputable
 import Control.Monad

-import List            ( partition, intersperse )
+import Data.List
+import System.IO

 import Maybes
 \end{code}
 
 import Maybes
 \end{code}
 

@@ -92,7 +88,7 @@ core2core hsc_env guts = do
     ann_env <- prepareAnnotations hsc_env (Just guts)
 
     -- COMPUTE THE RULE BASE TO USE
     ann_env <- prepareAnnotations hsc_env (Just guts)
 
     -- COMPUTE THE RULE BASE TO USE

-    (imp_rule_base, guts1) <- prepareRules hsc_env guts ru_us
+    (hpt_rule_base, guts1) <- prepareRules hsc_env guts ru_us

 
     -- Get the module out of the current HscEnv so we can retrieve it from the monad.
     -- This is very convienent for the users of the monad (e.g. plugins do not have to
 
     -- Get the module out of the current HscEnv so we can retrieve it from the monad.
     -- This is very convienent for the users of the monad (e.g. plugins do not have to

@@ -100,22 +96,18 @@ core2core hsc_env guts = do
     -- _theoretically_ be changed during the Core pipeline (it's part of ModGuts), which
     -- would mean our cached value would go out of date.
     let mod = mg_module guts
     -- _theoretically_ be changed during the Core pipeline (it's part of ModGuts), which
     -- would mean our cached value would go out of date.
     let mod = mg_module guts

-    (guts, stats) <- runCoreM hsc_env ann_env imp_rule_base cp_us mod $ do
+    (guts2, stats) <- runCoreM hsc_env ann_env hpt_rule_base cp_us mod $ do

         -- FIND BUILT-IN PASSES
         let builtin_core_todos = getCoreToDo dflags
 
         -- FIND BUILT-IN PASSES
         let builtin_core_todos = getCoreToDo dflags
 

-        -- Note [Injecting implicit bindings]
-        let implicit_binds = getImplicitBinds (mg_types guts1)
-            guts2 = guts1 { mg_binds = implicit_binds ++ mg_binds guts1 }
-

         -- DO THE BUSINESS
         -- DO THE BUSINESS

-        doCorePasses builtin_core_todos guts2
+        doCorePasses builtin_core_todos guts1

 
     Err.dumpIfSet_dyn dflags Opt_D_dump_simpl_stats
         "Grand total simplifier statistics"
         (pprSimplCount stats)
 
 
     Err.dumpIfSet_dyn dflags Opt_D_dump_simpl_stats
         "Grand total simplifier statistics"
         (pprSimplCount stats)
 

-    return guts
+    return guts2

 
 
 type CorePass = CoreToDo
 
 
 type CorePass = CoreToDo

@@ -125,6 +117,8 @@ simplifyExpr :: DynFlags -- includes spec of what core-to-core passes to do
             -> IO CoreExpr
 -- simplifyExpr is called by the driver to simplify an
 -- expression typed in at the interactive prompt
             -> IO CoreExpr
 -- simplifyExpr is called by the driver to simplify an
 -- expression typed in at the interactive prompt

+--
+-- Also used by Template Haskell

 simplifyExpr dflags expr
   = do {
        ; Err.showPass dflags "Simplify"
 simplifyExpr dflags expr
   = do {
        ; Err.showPass dflags "Simplify"

@@ -132,7 +126,7 @@ simplifyExpr dflags expr
        ; us <-  mkSplitUniqSupply 's'
 
        ; let (expr', _counts) = initSmpl dflags emptyRuleBase emptyFamInstEnvs us $
        ; us <-  mkSplitUniqSupply 's'
 
        ; let (expr', _counts) = initSmpl dflags emptyRuleBase emptyFamInstEnvs us $

-                                simplExprGently gentleSimplEnv expr
+                                simplExprGently simplEnvForGHCi expr

 
        ; Err.dumpIfSet_dyn dflags Opt_D_dump_simpl "Simplified expression"
                        (pprCoreExpr expr')
 
        ; Err.dumpIfSet_dyn dflags Opt_D_dump_simpl "Simplified expression"
                        (pprCoreExpr expr')

@@ -140,9 +134,6 @@ simplifyExpr dflags expr
        ; return expr'
        }
 
        ; return expr'
        }
 

-gentleSimplEnv :: SimplEnv
-gentleSimplEnv = mkSimplEnv SimplGently  (isAmongSimpl [])
-

 doCorePasses :: [CorePass] -> ModGuts -> CoreM ModGuts
 doCorePasses passes guts = foldM (flip doCorePass) guts passes
 
 doCorePasses :: [CorePass] -> ModGuts -> CoreM ModGuts
 doCorePasses passes guts = foldM (flip doCorePass) guts passes
 

@@ -185,7 +176,7 @@ doCorePass CoreDoSpecialising        = {-# SCC "Specialise" #-}
 
 doCorePass CoreDoSpecConstr          = {-# SCC "SpecConstr" #-}
                                        describePassR "SpecConstr" Opt_D_dump_spec $
 
 doCorePass CoreDoSpecConstr          = {-# SCC "SpecConstr" #-}
                                        describePassR "SpecConstr" Opt_D_dump_spec $

-                                       doPassDU  specConstrProgram
+                                       specConstrProgram

 
 doCorePass (CoreDoVectorisation be)  = {-# SCC "Vectorise" #-}
                                        describePass "Vectorisation" Opt_D_dump_vect $ 
 
 doCorePass (CoreDoVectorisation be)  = {-# SCC "Vectorise" #-}
                                        describePass "Vectorisation" Opt_D_dump_vect $ 

@@ -195,24 +186,8 @@ doCorePass CoreDoGlomBinds              = dontDescribePass $ doPassDM  glomBinds
 doCorePass CoreDoPrintCore              = dontDescribePass $ observe   printCore
 doCorePass (CoreDoRuleCheck phase pat)  = dontDescribePass $ ruleCheck phase pat
 
 doCorePass CoreDoPrintCore              = dontDescribePass $ observe   printCore
 doCorePass (CoreDoRuleCheck phase pat)  = dontDescribePass $ ruleCheck phase pat
 

-#ifdef OLD_STRICTNESS
-doCorePass CoreDoOldStrictness          = {-# SCC "OldStrictness" #-} doOldStrictness
-#endif
-

 doCorePass CoreDoNothing                = return
 doCorePass (CoreDoPasses passes)        = doCorePasses passes
 doCorePass CoreDoNothing                = return
 doCorePass (CoreDoPasses passes)        = doCorePasses passes

-
-#ifdef OLD_STRICTNESS
-doOldStrictness :: ModGuts -> CoreM ModGuts
-doOldStrictness guts
-  = do dfs <- getDynFlags
-       guts'  <- describePass "Strictness analysis" Opt_D_dump_stranal $ 
-                 doPassM (saBinds dfs) guts
-       guts'' <- describePass "Constructed Product analysis" Opt_D_dump_cpranal $ 
-                 doPass cprAnalyse guts'
-       return guts''
-#endif
-

 \end{code}
 
 %************************************************************************
 \end{code}
 
 %************************************************************************

@@ -230,10 +205,10 @@ describePass :: String -> DynFlag -> (ModGuts -> CoreM ModGuts) -> ModGuts -> Co
 describePass name dflag pass guts = do
     dflags <- getDynFlags
     
 describePass name dflag pass guts = do
     dflags <- getDynFlags
     

-    liftIO $ showPass dflags name
+    liftIO $ Err.showPass dflags name

     guts' <- pass guts
     guts' <- pass guts

-    liftIO $ endPass dflags name dflag (mg_binds guts')
-    
+    liftIO $ endPass dflags name dflag (mg_binds guts') (mg_rules guts')
+

     return guts'
 
 describePassD :: SDoc -> DynFlag -> (ModGuts -> CoreM ModGuts) -> ModGuts -> CoreM ModGuts
     return guts'
 
 describePassD :: SDoc -> DynFlag -> (ModGuts -> CoreM ModGuts) -> ModGuts -> CoreM ModGuts

@@ -307,48 +282,6 @@ observe do_pass = doPassM $ \binds -> do
 
 %************************************************************************
 %*                                                                     *
 
 %************************************************************************
 %*                                                                     *

-       Implicit bindings
-%*                                                                     *
-%************************************************************************
-
-Note [Injecting implicit bindings]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-We used to inject the implict bindings right at the end, in CoreTidy.
-But some of these bindings, notably record selectors, are not
-constructed in an optimised form.  E.g. record selector for
-       data T = MkT { x :: {-# UNPACK #-} !Int }
-Then the unfolding looks like
-       x = \t. case t of MkT x1 -> let x = I# x1 in x
-This generates bad code unless it's first simplified a bit.
-(Only matters when the selector is used curried; eg map x ys.)
-See Trac #2070.
-
-\begin{code}
-getImplicitBinds :: TypeEnv -> [CoreBind]
-getImplicitBinds type_env
-  = map get_defn (concatMap implicit_con_ids (typeEnvTyCons type_env)
-                 ++ concatMap other_implicit_ids (typeEnvElts type_env))
-       -- Put the constructor wrappers first, because
-       -- other implicit bindings (notably the fromT functions arising 
-       -- from generics) use the constructor wrappers.  At least that's
-       -- what External Core likes
-  where
-    implicit_con_ids tc = mapCatMaybes dataConWrapId_maybe (tyConDataCons tc)
-    
-    other_implicit_ids (ATyCon tc) = filter (not . isNaughtyRecordSelector) (tyConSelIds tc)
-       -- The "naughty" ones are not real functions at all
-       -- They are there just so we can get decent error messages
-       -- See Note  [Naughty record selectors] in MkId.lhs
-    other_implicit_ids (AClass cl) = classSelIds cl
-    other_implicit_ids _other      = []
-    
-    get_defn :: Id -> CoreBind
-    get_defn id = NonRec id (unfoldingTemplate (idUnfolding id))
-\end{code}
-
-
-%************************************************************************
-%*                                                                     *

        Dealing with rules
 %*                                                                     *
 %************************************************************************
        Dealing with rules
 %*                                                                     *
 %************************************************************************

@@ -380,7 +313,7 @@ prepareRules hsc_env@(HscEnv { hsc_dflags = dflags, hsc_HPT = hpt })
        ; let   -- Simplify the local rules; boringly, we need to make an in-scope set
                -- from the local binders, to avoid warnings from Simplify.simplVar
              local_ids        = mkInScopeSet (mkVarSet (bindersOfBinds binds))
        ; let   -- Simplify the local rules; boringly, we need to make an in-scope set
                -- from the local binders, to avoid warnings from Simplify.simplVar
              local_ids        = mkInScopeSet (mkVarSet (bindersOfBinds binds))

-             env              = setInScopeSet gentleSimplEnv local_ids 
+             env              = setInScopeSet simplEnvForRules local_ids 

              (simpl_rules, _) = initSmpl dflags emptyRuleBase emptyFamInstEnvs us $
                                 mapM (simplRule env) local_rules
 
              (simpl_rules, _) = initSmpl dflags emptyRuleBase emptyFamInstEnvs us $
                                 mapM (simplRule env) local_rules
 

@@ -388,18 +321,16 @@ prepareRules hsc_env@(HscEnv { hsc_dflags = dflags, hsc_HPT = hpt })
 
              home_pkg_rules = hptRules hsc_env (dep_mods deps)
              hpt_rule_base  = mkRuleBase home_pkg_rules
 
              home_pkg_rules = hptRules hsc_env (dep_mods deps)
              hpt_rule_base  = mkRuleBase home_pkg_rules

-             imp_rule_base  = extendRuleBaseList hpt_rule_base rules_for_imps
-
-             binds_w_rules = updateBinders rules_for_locals binds
+             binds_w_rules  = updateBinders rules_for_locals binds

 
 
        ; Err.dumpIfSet_dyn dflags Opt_D_dump_rules "Transformation rules"
                (withPprStyle (mkUserStyle (mkPrintUnqualified dflags rdr_env) AllTheWay) $
                 vcat [text "Local rules", pprRules simpl_rules,
 
 
        ; Err.dumpIfSet_dyn dflags Opt_D_dump_rules "Transformation rules"
                (withPprStyle (mkUserStyle (mkPrintUnqualified dflags rdr_env) AllTheWay) $
                 vcat [text "Local rules", pprRules simpl_rules,

-                      text "",
-                      text "Imported rules", pprRuleBase imp_rule_base])
+                      blankLine,
+                      text "Imported rules", pprRuleBase hpt_rule_base])

 
 

-       ; return (imp_rule_base, guts { mg_binds = binds_w_rules, 
+       ; return (hpt_rule_base, guts { mg_binds = binds_w_rules, 

                                        mg_rules = rules_for_imps })
     }
 
                                        mg_rules = rules_for_imps })
     }
 

@@ -458,13 +389,15 @@ The simplifier does indeed do eta reduction (it's in
 Simplify.completeLam) but only if -O is on.
 
 \begin{code}
 Simplify.completeLam) but only if -O is on.
 
 \begin{code}

+simplRule :: SimplEnv -> CoreRule -> SimplM CoreRule

 simplRule env rule@(BuiltinRule {})
   = return rule
 simplRule env rule@(Rule { ru_bndrs = bndrs, ru_args = args, ru_rhs = rhs })
   = do (env, bndrs') <- simplBinders env bndrs
        args' <- mapM (simplExprGently env) args
        rhs' <- simplExprGently env rhs
 simplRule env rule@(BuiltinRule {})
   = return rule
 simplRule env rule@(Rule { ru_bndrs = bndrs, ru_args = args, ru_rhs = rhs })
   = do (env, bndrs') <- simplBinders env bndrs
        args' <- mapM (simplExprGently env) args
        rhs' <- simplExprGently env rhs

-       return (rule { ru_bndrs = bndrs', ru_args = args', ru_rhs = rhs' })
+       return (rule { ru_bndrs = bndrs', ru_args = args'
+                    , ru_rhs = occurAnalyseExpr rhs' })

 \end{code}
 
 \begin{code}
 \end{code}
 
 \begin{code}

@@ -547,45 +480,49 @@ simplifyPgm mode switches
     do { hsc_env <- getHscEnv
        ; us <- getUniqueSupplyM
        ; rb <- getRuleBase
     do { hsc_env <- getHscEnv
        ; us <- getUniqueSupplyM
        ; rb <- getRuleBase

-       ; let fam_inst_env = mg_fam_inst_env guts
-             dump_phase = shouldDumpSimplPhase (hsc_dflags hsc_env) mode
-            simplify_pgm = simplifyPgmIO dump_phase mode switches 
-                                          hsc_env us rb fam_inst_env
-
-       ; doPassM (liftIOWithCount . simplify_pgm) guts }
+       ; liftIOWithCount $  
+                simplifyPgmIO mode switches hsc_env us rb guts }

   where
     doc = ptext (sLit "Simplifier Phase") <+> text (showPpr mode) 
 
   where
     doc = ptext (sLit "Simplifier Phase") <+> text (showPpr mode) 
 

-simplifyPgmIO :: Bool
-            -> SimplifierMode
-           -> [SimplifierSwitch]
-           -> HscEnv
-           -> UniqSupply
-           -> RuleBase
-           -> FamInstEnv
-           -> [CoreBind]
-           -> IO (SimplCount, [CoreBind])  -- New bindings
-
-simplifyPgmIO dump_phase mode switches hsc_env us imp_rule_base fam_inst_env binds
+simplifyPgmIO :: SimplifierMode
+             -> [SimplifierSwitch]
+             -> HscEnv
+             -> UniqSupply
+             -> RuleBase
+             -> ModGuts
+             -> IO (SimplCount, ModGuts)  -- New bindings
+
+simplifyPgmIO mode switches hsc_env us hpt_rule_base 
+              guts@(ModGuts { mg_binds = binds, mg_rules = rules
+                            , mg_fam_inst_env = fam_inst_env })

   = do {
   = do {

-       (termination_msg, it_count, counts_out, binds') 
-          <- do_iteration us 1 (zeroSimplCount dflags) binds ;
+       (termination_msg, it_count, counts_out, guts') 
+          <- do_iteration us 1 (zeroSimplCount dflags) binds rules ;

 
        Err.dumpIfSet (dump_phase && dopt Opt_D_dump_simpl_stats dflags)
                  "Simplifier statistics for following pass"
                  (vcat [text termination_msg <+> text "after" <+> ppr it_count <+> text "iterations",
 
        Err.dumpIfSet (dump_phase && dopt Opt_D_dump_simpl_stats dflags)
                  "Simplifier statistics for following pass"
                  (vcat [text termination_msg <+> text "after" <+> ppr it_count <+> text "iterations",

-                        text "",
+                        blankLine,

                         pprSimplCount counts_out]);
 
                         pprSimplCount counts_out]);
 

-       return (counts_out, binds')
+       return (counts_out, guts')

     }
   where
     }
   where

-    dflags        = hsc_dflags hsc_env
+    dflags              = hsc_dflags hsc_env
+    dump_phase          = shouldDumpSimplPhase dflags mode

                   
     sw_chkr       = isAmongSimpl switches
     max_iterations = intSwitchSet sw_chkr MaxSimplifierIterations `orElse` 2
  
                   
     sw_chkr       = isAmongSimpl switches
     max_iterations = intSwitchSet sw_chkr MaxSimplifierIterations `orElse` 2
  

-    do_iteration us iteration_no counts binds
+    do_iteration :: UniqSupply
+                 -> Int                -- Counts iterations
+                -> SimplCount  -- Logs optimisations performed
+                -> [CoreBind]  -- Bindings in
+                -> [CoreRule]  -- and orphan rules
+                -> IO (String, Int, SimplCount, ModGuts)
+
+    do_iteration us iteration_no counts binds rules

        -- iteration_no is the number of the iteration we are
        -- about to begin, with '1' for the first
       | iteration_no > max_iterations  -- Stop if we've run out of iterations
        -- iteration_no is the number of the iteration we are
        -- about to begin, with '1' for the first
       | iteration_no > max_iterations  -- Stop if we've run out of iterations

@@ -595,14 +532,15 @@ simplifyPgmIO dump_phase mode switches hsc_env us imp_rule_base fam_inst_env bin
                                " iterations; bailing out.  Size = " ++ show (coreBindsSize binds) ++ "\n" ))
                -- Subtract 1 from iteration_no to get the
                -- number of iterations we actually completed
                                " iterations; bailing out.  Size = " ++ show (coreBindsSize binds) ++ "\n" ))
                -- Subtract 1 from iteration_no to get the
                -- number of iterations we actually completed

-           return ("Simplifier bailed out", iteration_no - 1, counts, binds)
+           return ("Simplifier bailed out", iteration_no - 1, counts, 
+                    guts { mg_binds = binds, mg_rules = rules })

 
       -- Try and force thunks off the binds; significantly reduces
       -- space usage, especially with -O.  JRS, 000620.
       | let sz = coreBindsSize binds in sz == sz
       = do {
                -- Occurrence analysis
 
       -- Try and force thunks off the binds; significantly reduces
       -- space usage, especially with -O.  JRS, 000620.
       | let sz = coreBindsSize binds in sz == sz
       = do {
                -- Occurrence analysis

-          let { tagged_binds = {-# SCC "OccAnal" #-} occurAnalysePgm binds } ;
+          let { tagged_binds = {-# SCC "OccAnal" #-} occurAnalysePgm binds rules } ;

           Err.dumpIfSet_dyn dflags Opt_D_dump_occur_anal "Occurrence analysis"
                     (pprCoreBindings tagged_binds);
 
           Err.dumpIfSet_dyn dflags Opt_D_dump_occur_anal "Occurrence analysis"
                     (pprCoreBindings tagged_binds);
 

@@ -612,8 +550,9 @@ simplifyPgmIO dump_phase mode switches hsc_env us imp_rule_base fam_inst_env bin
                -- behind the scenes.  Otherwise there's a danger we'll simply
                -- miss the rules for Ids hidden inside imported inlinings
           eps <- hscEPS hsc_env ;
                -- behind the scenes.  Otherwise there's a danger we'll simply
                -- miss the rules for Ids hidden inside imported inlinings
           eps <- hscEPS hsc_env ;

-          let  { rule_base' = unionRuleBase imp_rule_base (eps_rule_base eps)
-               ; simpl_env  = mkSimplEnv mode sw_chkr 
+          let  { rule_base1 = unionRuleBase hpt_rule_base (eps_rule_base eps)
+               ; rule_base2 = extendRuleBaseList rule_base1 rules
+               ; simpl_env  = mkSimplEnv sw_chkr mode

                ; simpl_binds = {-# SCC "SimplTopBinds" #-} 
                                simplTopBinds simpl_env tagged_binds
                ; fam_envs = (eps_fam_inst_env eps, fam_inst_env) } ;
                ; simpl_binds = {-# SCC "SimplTopBinds" #-} 
                                simplTopBinds simpl_env tagged_binds
                ; fam_envs = (eps_fam_inst_env eps, fam_inst_env) } ;

@@ -629,19 +568,18 @@ simplifyPgmIO dump_phase mode switches hsc_env us imp_rule_base fam_inst_env bin
                --      case t of {(_,counts') -> if counts'=0 then ... }
                -- So the conditional didn't force counts', because the
                -- selection got duplicated.  Sigh!
                --      case t of {(_,counts') -> if counts'=0 then ... }
                -- So the conditional didn't force counts', because the
                -- selection got duplicated.  Sigh!

-          case initSmpl dflags rule_base' fam_envs us1 simpl_binds of {
-               (binds', counts') -> do {
+          case initSmpl dflags rule_base2 fam_envs us1 simpl_binds of {
+               (env1, counts1) -> do {

 
 

-          let  { all_counts = counts `plusSimplCount` counts'
-               ; herald     = "Simplifier mode " ++ showPpr mode ++ 
-                             ", iteration " ++ show iteration_no ++
-                             " out of " ++ show max_iterations
+          let  { all_counts = counts `plusSimplCount` counts1
+               ; binds1 = getFloats env1
+                ; rules1 = substRulesForImportedIds (mkCoreSubst env1) rules

                } ;
 
                -- Stop if nothing happened; don't dump output
                } ;
 
                -- Stop if nothing happened; don't dump output

-          if isZeroSimplCount counts' then
-               return ("Simplifier reached fixed point", iteration_no, 
-                       all_counts, binds')
+          if isZeroSimplCount counts1 then
+               return ("Simplifier reached fixed point", iteration_no, all_counts,
+                       guts { mg_binds = binds1, mg_rules = rules1 })

           else do {
                -- Short out indirections
                -- We do this *after* at least one run of the simplifier 
           else do {
                -- Short out indirections
                -- We do this *after* at least one run of the simplifier 

@@ -651,18 +589,30 @@ simplifyPgmIO dump_phase mode switches hsc_env us imp_rule_base fam_inst_env bin
                --
                -- ToDo: alas, this means that indirection-shorting does not happen at all
                --       if the simplifier does nothing (not common, I know, but unsavoury)
                --
                -- ToDo: alas, this means that indirection-shorting does not happen at all
                --       if the simplifier does nothing (not common, I know, but unsavoury)

-          let { binds'' = {-# SCC "ZapInd" #-} shortOutIndirections binds' } ;
+          let { binds2 = {-# SCC "ZapInd" #-} shortOutIndirections binds1 } ;

 
                -- Dump the result of this iteration
 
                -- Dump the result of this iteration

-          Err.dumpIfSet_dyn dflags Opt_D_dump_simpl_iterations herald
-                        (pprSimplCount counts') ;
-          endIteration dflags herald Opt_D_dump_simpl_iterations binds'' ;
+          end_iteration dflags mode iteration_no max_iterations counts1 binds2 rules1 ;

 
                -- Loop
 
                -- Loop

-          do_iteration us2 (iteration_no + 1) all_counts binds''
+          do_iteration us2 (iteration_no + 1) all_counts binds2 rules1

        }  } } }
       where
          (us1, us2) = splitUniqSupply us
        }  } } }
       where
          (us1, us2) = splitUniqSupply us

+
+-------------------
+end_iteration :: DynFlags -> SimplifierMode -> Int -> Int 
+             -> SimplCount -> [CoreBind] -> [CoreRule] -> IO ()
+-- Same as endIteration but with simplifier counts
+end_iteration dflags mode iteration_no max_iterations counts binds rules
+  = do { Err.dumpIfSet_dyn dflags Opt_D_dump_simpl_iterations pass_name
+                            (pprSimplCount counts) ;
+
+       ; endIteration dflags pass_name Opt_D_dump_simpl_iterations binds rules }
+  where
+    pass_name = "Simplifier mode " ++ showPpr mode ++ 
+               ", iteration " ++ show iteration_no ++
+               " out of " ++ show max_iterations

 \end{code}
 
 
 \end{code}
 
 

@@ -689,23 +639,21 @@ save a gratuitous jump (from \tr{x_exported} to \tr{x_local}), and
 makes strictness information propagate better.  This used to happen in
 the final phase, but it's tidier to do it here.
 
 makes strictness information propagate better.  This used to happen in
 the final phase, but it's tidier to do it here.
 

+Note [Transferring IdInfo]
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+We want to propagage any useful IdInfo on x_local to x_exported.
+

 STRICTNESS: if we have done strictness analysis, we want the strictness info on
 x_local to transfer to x_exported.  Hence the copyIdInfo call.
 
 RULES: we want to *add* any RULES for x_local to x_exported.
 
 STRICTNESS: if we have done strictness analysis, we want the strictness info on
 x_local to transfer to x_exported.  Hence the copyIdInfo call.
 
 RULES: we want to *add* any RULES for x_local to x_exported.
 

-Note [Rules and indirection-zapping]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Problem: what if x_exported has a RULE that mentions something in ...bindings...?
-Then the things mentioned can be out of scope!  Solution
- a) Make sure that in this pass the usage-info from x_exported is 
-       available for ...bindings...
- b) If there are any such RULES, rec-ify the entire top-level. 
-    It'll get sorted out next time round

 
 

-Messing up the rules
-~~~~~~~~~~~~~~~~~~~~
-The example that went bad on me at one stage was this one:
+Note [Messing up the exported Id's RULES]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+We must be careful about discarding (obviously) or even merging the
+RULES on the exported Id. The example that went bad on me at one stage
+was this one:

        
     iterate :: (a -> a) -> a -> [a]
        [Exported]
        
     iterate :: (a -> a) -> a -> [a]
        [Exported]

@@ -738,13 +686,28 @@ And now we get an infinite loop in the rule system
                    -> iterateFB (:) f x
                    -> iterate f x
 
                    -> iterateFB (:) f x
                    -> iterate f x
 

-Tiresome old solution: 
-       don't do shorting out if f has rewrite rules (see shortableIdInfo)
-
-New solution (I think): 
+Old "solution": 

        use rule switching-off pragmas to get rid 
        of iterateList in the first place
 
        use rule switching-off pragmas to get rid 
        of iterateList in the first place
 

+But in principle the user *might* want rules that only apply to the Id
+he says.  And inline pragmas are similar
+   {-# NOINLINE f #-}
+   f = local
+   local = <stuff>
+Then we do not want to get rid of the NOINLINE.
+
+Hence hasShortableIdinfo.
+
+
+Note [Rules and indirection-zapping]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Problem: what if x_exported has a RULE that mentions something in ...bindings...?
+Then the things mentioned can be out of scope!  Solution
+ a) Make sure that in this pass the usage-info from x_exported is 
+       available for ...bindings...
+ b) If there are any such RULES, rec-ify the entire top-level. 
+    It'll get sorted out next time round

 
 Other remarks
 ~~~~~~~~~~~~~
 
 Other remarks
 ~~~~~~~~~~~~~

@@ -815,6 +778,7 @@ makeIndEnv binds
     add_pair (exported_id, rhs) env
        = env
                        
     add_pair (exported_id, rhs) env
        = env
                        

+-----------------

 shortMeOut ind_env exported_id local_id
 -- The if-then-else stuff is just so I can get a pprTrace to see
 -- how often I don't get shorting out becuase of IdInfo stuff
 shortMeOut ind_env exported_id local_id
 -- The if-then-else stuff is just so I can get a pprTrace to see
 -- how often I don't get shorting out becuase of IdInfo stuff

@@ -829,23 +793,27 @@ shortMeOut ind_env exported_id local_id
    
        not (local_id `elemVarEnv` ind_env)     -- Only if not already substituted for
     then
    
        not (local_id `elemVarEnv` ind_env)     -- Only if not already substituted for
     then

-       True
-
-{- No longer needed
-       if isEmptySpecInfo (specInfo (idInfo exported_id))      -- Only if no rules
-       then True       -- See note on "Messing up rules"
-       else 
-#ifdef DEBUG 
-          pprTrace "shortMeOut:" (ppr exported_id)
-#endif
-                                                False
--}
+       if hasShortableIdInfo exported_id
+       then True       -- See Note [Messing up the exported Id's IdInfo]
+       else WARN( True, ptext (sLit "Not shorting out:") <+> ppr exported_id )
+             False

     else
     else

-       False
+        False

 
 

+-----------------
+hasShortableIdInfo :: Id -> Bool
+-- True if there is no user-attached IdInfo on exported_id,
+-- so we can safely discard it
+-- See Note [Messing up the exported Id's IdInfo]
+hasShortableIdInfo id
+  =  isEmptySpecInfo (specInfo info)
+  && isDefaultInlinePragma (inlinePragInfo info)
+  where
+     info = idInfo id

 
 -----------------
 transferIdInfo :: Id -> Id -> Id
 
 -----------------
 transferIdInfo :: Id -> Id -> Id

+-- See Note [Transferring IdInfo]

 -- If we have
 --     lcl_id = e; exp_id = lcl_id
 -- and lcl_id has useful IdInfo, we don't want to discard it by going
 -- If we have
 --     lcl_id = e; exp_id = lcl_id
 -- and lcl_id has useful IdInfo, we don't want to discard it by going

@@ -856,7 +824,7 @@ transferIdInfo exported_id local_id
   = modifyIdInfo transfer exported_id
   where
     local_info = idInfo local_id
   = modifyIdInfo transfer exported_id
   where
     local_info = idInfo local_id

-    transfer exp_info = exp_info `setNewStrictnessInfo` newStrictnessInfo local_info
+    transfer exp_info = exp_info `setStrictnessInfo` strictnessInfo local_info

                                 `setUnfoldingInfo`     unfoldingInfo local_info
                                 `setInlinePragInfo`    inlinePragInfo local_info
                                 `setSpecInfo`          addSpecInfo (specInfo exp_info) new_info
                                 `setUnfoldingInfo`     unfoldingInfo local_info
                                 `setInlinePragInfo`    inlinePragInfo local_info
                                 `setSpecInfo`          addSpecInfo (specInfo exp_info) new_info