Bottom extraction: float out bottoming expressions to top level

[ghc-hetmet.git] / compiler / main / TidyPgm.lhs

diff --git a/compiler/main/TidyPgm.lhs b/compiler/main/TidyPgm.lhs
index ffe0eca..41d9234 100644 (file)
--- a/compiler/main/TidyPgm.lhs
+++ b/compiler/main/TidyPgm.lhs
@@ -26,7 +26,7 @@ import Var
 import Id
 import IdInfo
 import InstEnv
-import NewDemand
+import Demand
 import BasicTypes
 import Name hiding (varName)
 import NameSet
@@ -310,6 +310,8 @@ tidyProgram hsc_env  (ModGuts { mg_module = mod, mg_exports = exports,
                                    binds implicit_binds imp_rules
 
         ; let { ext_rules = findExternalRules omit_prags binds imp_rules unfold_env }
+               -- Glom together imp_rules and rules currently attached to binders
+               -- Then pick just the ones we need to expose
                -- See Note [Which rules to expose]
 
        ; let { (tidy_env, tidy_binds)
@@ -686,7 +688,7 @@ addExternal expose_all id = (new_needed_ids, show_unfold)
     idinfo        = idInfo id
     dont_inline           = isNeverActive (inlinePragmaActivation (inlinePragInfo idinfo))
     loop_breaker   = isNonRuleLoopBreaker (occInfo idinfo)
-    bottoming_fn   = isBottomingSig (newStrictnessInfo idinfo `orElse` topSig)
+    bottoming_fn   = isBottomingSig (strictnessInfo idinfo `orElse` topSig)
     spec_ids      = specInfoFreeVars (specInfo idinfo)
 
        -- Stuff to do with the Id's unfolding
@@ -981,21 +983,24 @@ tidyTopPair show_unfold rhs_tidy_env caf_info name' (bndr, rhs)
     -- the RHS is bottom, it should jolly well be exposed
     _bottom_exposed = case exprBotStrictness_maybe rhs of
                         Nothing         -> True
-                        Just (arity, _) -> appIsBottom str arity
+                        Just (arity, _) -> appIsBottom str_sig arity
         where
-          str = newStrictnessInfo idinfo `orElse` topSig
-
-    bndr1   = mkGlobalId details name' ty' idinfo'
-    details = idDetails bndr   -- Preserve the IdDetails
-    ty'            = tidyTopType (idType bndr)
-    rhs1    = tidyExpr rhs_tidy_env rhs
-    idinfo  = idInfo bndr
-    idinfo' = tidyTopIdInfo (isExternalName name')
+
+
+    bndr1    = mkGlobalId details name' ty' idinfo'
+    details  = idDetails bndr  -- Preserve the IdDetails
+    ty'             = tidyTopType (idType bndr)
+    rhs1     = tidyExpr rhs_tidy_env rhs
+    idinfo   = idInfo bndr
+    unf_info = unfoldingInfo idinfo
+    str_sig  = strictnessInfo idinfo `orElse` topSig
+    is_bot   = isBottomingSig str_sig
+    idinfo'  = tidyTopIdInfo (isExternalName name')
                            idinfo unfold_info
                            arity caf_info 
                             (occInfo idinfo)
 
-    unfold_info | show_unfold = tidyUnfolding rhs_tidy_env rhs1 (unfoldingInfo idinfo)
+    unfold_info | show_unfold = tidyUnfolding rhs_tidy_env rhs1 is_bot unf_info
                | otherwise   = noUnfolding
     -- NB: do *not* expose the worker if show_unfold is off,
     --     because that means this thing is a loop breaker or
@@ -1043,14 +1048,14 @@ tidyTopIdInfo is_external idinfo unfold_info arity caf_info occ_info
         `setOccInfo`           robust_occ_info
        `setCafInfo`           caf_info
        `setArityInfo`         arity
-       `setAllStrictnessInfo` newStrictnessInfo idinfo
+       `setStrictnessInfo` strictnessInfo idinfo
 
   | otherwise          -- Externally-visible Ids get the whole lot
   = vanillaIdInfo
         `setOccInfo`           robust_occ_info
        `setCafInfo`           caf_info
        `setArityInfo`         arity
-       `setAllStrictnessInfo` newStrictnessInfo idinfo
+       `setStrictnessInfo` strictnessInfo idinfo
        `setInlinePragInfo`    inlinePragInfo idinfo
        `setUnfoldingInfo`     unfold_info
                -- NB: we throw away the Rules
@@ -1063,20 +1068,21 @@ tidyTopIdInfo is_external idinfo unfold_info arity caf_info occ_info
 
 
 ------------ Unfolding  --------------
-tidyUnfolding :: TidyEnv -> CoreExpr -> Unfolding -> Unfolding
-tidyUnfolding tidy_env _ unf@(CoreUnfolding { uf_tmpl = rhs 
-                                           , uf_guidance = guide@(InlineRule {}) })
-  = unf { uf_tmpl     = tidyExpr tidy_env rhs,            -- Preserves OccInfo
-         uf_guidance = guide { ir_info = tidyInl tidy_env (ir_info guide) } }
-tidyUnfolding tidy_env _ (DFunUnfolding con ids)
+tidyUnfolding :: TidyEnv -> CoreExpr -> Bool -> Unfolding -> Unfolding
+tidyUnfolding tidy_env _ _ (DFunUnfolding con ids)
   = DFunUnfolding con (map (tidyExpr tidy_env) ids)
-tidyUnfolding _ tidy_rhs (CoreUnfolding {})
-  = mkTopUnfolding tidy_rhs
-tidyUnfolding _ _ unf = unf
-
-tidyInl :: TidyEnv -> InlineRuleInfo -> InlineRuleInfo
-tidyInl tidy_env (InlWrapper w) = InlWrapper (tidyVarOcc tidy_env w)
-tidyInl _        inl_info       = inl_info
+tidyUnfolding tidy_env tidy_rhs is_bottoming
+              unf@(CoreUnfolding { uf_tmpl = unf_rhs, uf_src = src })
+  | isInlineRuleSource src
+  = unf { uf_tmpl = tidyExpr tidy_env unf_rhs,            -- Preserves OccInfo
+         uf_src  = tidyInl tidy_env src }
+  | otherwise
+  = mkTopUnfolding is_bottoming tidy_rhs
+tidyUnfolding _ _ _ unf = unf
+
+tidyInl :: TidyEnv -> UnfoldingSource -> UnfoldingSource
+tidyInl tidy_env (InlineWrapper w) = InlineWrapper (tidyVarOcc tidy_env w)
+tidyInl _        inl_info          = inl_info
 \end{code}
 
 %************************************************************************