[project @ 1998-03-13 17:36:27 by simonpj]

Still a lingering lost-Eval-dict bug; but nearly there!

ghc/compiler/simplCore/SimplEnv.lhs

@@ -53,7 +53,10 @@ import CoreUnfold	( mkFormSummary, couldBeSmallEnoughToInline, whnfOrBottom,
 			  Unfolding(..), FormSummary(..),
 			  calcUnfoldingGuidance	)
 import CoreUtils	( coreExprCc )
-import CostCentre	( CostCentre, isCurrentCostCentre, useCurrentCostCentre, costsAreSubsumed, noCostCentreAttached )
+import CostCentre	( CostCentre, isCurrentCostCentre, useCurrentCostCentre, 
+			  costsAreSubsumed, noCostCentreAttached, subsumedCosts,
+			  currentOrSubsumedCosts
+			)
 import FiniteMap	-- lots of things
 import Id		( getInlinePragma,
 			  nullIdEnv, growIdEnvList, lookupIdEnv, delOneFromIdEnv,
@@ -177,11 +180,19 @@ type StuffAboutId = (OutId, 		-- Always has the same unique as the
 nullSimplEnv :: SwitchChecker -> SimplEnv
 
 nullSimplEnv sw_chkr
-  = SimplEnv sw_chkr useCurrentCostCentre 
+  = SimplEnv sw_chkr subsumedCosts
 	     (emptyTyVarSet, emptyTyVarEnv)
 	     (nullIdEnv, nullIdEnv)
 	     nullConApps
 
+	-- The top level "enclosing CC" is "SUBSUMED".  But the enclosing CC
+	-- for the rhs of top level defs is "OST_CENTRE".  Consider
+	--	f = \x -> e
+	--	g = \y -> let v = f y in scc "x" (v ...)
+	-- Here we want to inline "f", since its CC is SUBSUMED, but we don't
+	-- want to inline "v" since its CC is dynamically determined.
+
+
 getEnvs :: SimplEnv -> (SimplTypeEnv, SimplValEnv)
 getEnvs (SimplEnv _ _ ty_env id_env _) = (ty_env, id_env)
 
@@ -282,9 +293,6 @@ switchOffInlining (SimplEnv chkr encl_cc ty_env (in_scope_ids, id_subst) con_app
 setEnclosingCC :: SimplEnv -> CostCentre -> SimplEnv
 
 setEnclosingCC env@(SimplEnv chkr _ ty_env id_env con_apps) encl_cc
-  | costsAreSubsumed encl_cc
-  = env
-  | otherwise
   = SimplEnv chkr encl_cc ty_env id_env con_apps
 
 getEnclosingCC :: SimplEnv -> CostCentre
@@ -643,7 +651,7 @@ extendEnvGivenBinding env@(SimplEnv chkr encl_cc ty_env (in_scope_ids, id_subst)
 	       mkSimplUnfoldingGuidance chkr out_id rhs
 
 	-- Attach a cost centre to the RHS if necessary
-    rhs_w_cc  | isCurrentCostCentre encl_cc
+    rhs_w_cc  | currentOrSubsumedCosts encl_cc
 	      || not (noCostCentreAttached (coreExprCc rhs))
 	      = rhs
 	      | otherwise

ghc/compiler/simplCore/SimplVar.lhs

@@ -172,7 +172,7 @@ When we hit a binder we may need to
 
 \begin{code}
 simplBinder :: SimplEnv -> InBinder -> SmplM (SimplEnv, OutId)
-simplBinder env (id, _)
+simplBinder env (id, occ_info)
   |  not_in_scope	 	-- Not in scope, so no need to clone
   && empty_ty_subst 		-- No type substitution to do inside the Id
   && isNullIdEnv id_subst	-- No id substitution to do inside the Id
@@ -219,7 +219,7 @@ simplBinder env (id, _)
     empty_ty_subst   	 = isEmptyTyVarEnv ty_subst
     not_in_scope     	 = not (id `elemIdEnv` in_scope_ids)
 
-    new_in_scope_ids id' = addOneToIdEnv in_scope_ids id' (id', noBinderInfo, NoUnfolding)
+    new_in_scope_ids id' = addOneToIdEnv in_scope_ids id' (id', occ_info, NoUnfolding)
     
     ty               	 = idType id
     ty'              	 = instantiateTy ty_subst ty

ghc/compiler/simplCore/Simplify.lhs

@@ -500,7 +500,7 @@ simplRhsExpr env binder@(id,occ_info) rhs new_id
 
   | otherwise	-- OK, use the big hammer
   = 	-- Deal with the big lambda part
-    simplTyBinders env tyvars			`thenSmpl` \ (lam_env, tyvars') ->
+    simplTyBinders rhs_env tyvars			`thenSmpl` \ (lam_env, tyvars') ->
     let
 	body_ty  = applyTys rhs_ty (mkTyVarTys tyvars')
     in

ghc/compiler/specialise/Specialise.lhs

@@ -1167,17 +1167,32 @@ instantiateDictRhs :: TyVarEnv Type -> IdEnv Id -> CoreExpr -> CoreExpr
 instantiateDictRhs ty_env id_env rhs
   = go rhs
   where
-    go (App e1 (VarArg a)) = App (go e1) (VarArg (lookupId id_env a))
-    go (App e1 (TyArg t))  = App (go e1) (TyArg (instantiateTy ty_env t))
-    go (Var v)		   = Var (lookupId id_env v)
-    go (Lit l)		   = Lit l
+    go_arg (VarArg a) = VarArg (lookupId id_env a)
+    go_arg (TyArg t)  = TyArg (instantiateTy ty_env t)
+
+    go (App e1 arg)   = App (go e1) (go_arg arg)
+    go (Var v)	      = Var (lookupId id_env v)
+    go (Lit l)	      = Lit l
+    go (Con con args) = Con con (map go_arg args)
+    go (Case e alts)  = Case (go e) alts		-- See comment below re alts
+    go other	      = pprPanic "instantiateDictRhs" (ppr rhs)
 
 dictRhsFVs :: CoreExpr -> IdSet
 	-- Cheapo function for simple RHSs
-dictRhsFVs (App e1 (VarArg a)) = dictRhsFVs e1 `addOneToIdSet` a
-dictRhsFVs (App e1 (TyArg t))  = dictRhsFVs e1
-dictRhsFVs (Var v)	       = unitIdSet v
-dictRhsFVs (Lit l)	       = emptyIdSet
+dictRhsFVs e
+  = go e
+  where
+    go (App e1 (VarArg a)) = go e1 `addOneToIdSet` a
+    go (App e1 (TyArg t))  = go e1
+    go (Var v)	           = unitIdSet v
+    go (Lit l)	           = emptyIdSet
+    go (Con _ args)        = mkIdSet [id | VarArg id <- args]
+
+    go (Case e _)	   = go e	-- Claim: no free dictionaries in the alternatives
+					-- These case expressions are of the form
+					--   case d of { D a b c -> b }
+
+    go other		   = pprPanic "dictRhsFVs" (ppr e)
 
 
 addIdSpecialisations id spec_stuff