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

diff --git a/compiler/simplCore/SimplCore.lhs b/compiler/simplCore/SimplCore.lhs
index 62c3c35..df928f6 100644 (file)
--- a/compiler/simplCore/SimplCore.lhs
+++ b/compiler/simplCore/SimplCore.lhs
@@ -31,6 +31,7 @@ import OccurAnal      ( occurAnalysePgm, occurAnalyseExpr )
 import IdInfo
 import CoreUtils       ( coreBindsSize )
 import Simplify                ( simplTopBinds, simplExpr )
+import SimplUtils      ( simplEnvForGHCi, simplEnvForRules )
 import SimplEnv
 import SimplMonad
 import CoreMonad
@@ -120,6 +121,8 @@ 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
+--
+-- Also used by Template Haskell
 simplifyExpr dflags expr
   = do {
        ; Err.showPass dflags "Simplify"
@@ -127,7 +130,7 @@ simplifyExpr dflags expr
        ; 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')
@@ -135,9 +138,6 @@ simplifyExpr dflags expr
        ; return expr'
        }
 
-gentleSimplEnv :: SimplEnv
-gentleSimplEnv = mkSimplEnv SimplGently  (isAmongSimpl [])
-
 doCorePasses :: [CorePass] -> ModGuts -> CoreM ModGuts
 doCorePasses passes guts = foldM (flip doCorePass) guts passes
 
@@ -333,7 +333,7 @@ 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))
-             env              = setInScopeSet gentleSimplEnv local_ids 
+             env              = setInScopeSet simplEnvForRules local_ids 
              (simpl_rules, _) = initSmpl dflags emptyRuleBase emptyFamInstEnvs us $
                                 mapM (simplRule env) local_rules
 
@@ -409,6 +409,7 @@ The simplifier does indeed do eta reduction (it's in
 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 })
@@ -571,7 +572,7 @@ simplifyPgmIO mode switches hsc_env us hpt_rule_base
           eps <- hscEPS hsc_env ;
           let  { rule_base1 = unionRuleBase hpt_rule_base (eps_rule_base eps)
                ; rule_base2 = extendRuleBaseList rule_base1 rules
-               ; simpl_env  = mkSimplEnv mode sw_chkr 
+               ; 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) } ;
@@ -611,7 +612,7 @@ simplifyPgmIO mode switches hsc_env us hpt_rule_base
           let { binds2 = {-# SCC "ZapInd" #-} shortOutIndirections binds1 } ;
 
                -- Dump the result of this iteration
-          endIteration dflags mode iteration_no max_iterations counts1 binds2 rules1 ;
+          end_iteration dflags mode iteration_no max_iterations counts1 binds2 rules1 ;
 
                -- Loop
           do_iteration us2 (iteration_no + 1) all_counts binds2 rules1
@@ -620,14 +621,14 @@ simplifyPgmIO mode switches hsc_env us hpt_rule_base
          (us1, us2) = splitUniqSupply us
 
 -------------------
-endIteration :: DynFlags -> SimplifierMode -> Int -> Int 
+end_iteration :: DynFlags -> SimplifierMode -> Int -> Int 
              -> SimplCount -> [CoreBind] -> [CoreRule] -> IO ()
--- Same as endPass but with simplifier counts
-endIteration dflags mode iteration_no max_iterations counts binds rules
+-- 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) ;
 
-       ; endPass dflags pass_name Opt_D_dump_simpl_iterations binds rules }
+       ; endIteration dflags pass_name Opt_D_dump_simpl_iterations binds rules }
   where
     pass_name = "Simplifier mode " ++ showPpr mode ++ 
                ", iteration " ++ show iteration_no ++
@@ -668,11 +669,11 @@ 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 [Messing up the exported Id's IdInfo]
+Note [Messing up the exported Id's RULES]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-We must be careful about discarding the IdInfo on the old Id
-
-The example that went bad on me at one stage was this one:
+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]