Second bite at the rules-only idea

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

diff --git a/compiler/main/TidyPgm.lhs b/compiler/main/TidyPgm.lhs
index 4e01fd3..976c32e 100644 (file)
--- a/compiler/main/TidyPgm.lhs
+++ b/compiler/main/TidyPgm.lhs
@@ -26,7 +26,7 @@ import Id             ( idType, idInfo, idName, idCoreRules, isGlobalId,
 import IdInfo          {- loads of stuff -}
 import InstEnv         ( Instance, DFunId, instanceDFunId, setInstanceDFunId )
 import NewDemand       ( isBottomingSig, topSig )
-import BasicTypes      ( Arity, isNeverActive )
+import BasicTypes      ( Arity, isNeverActive, isNonRuleLoopBreaker )
 import Name            ( Name, getOccName, nameOccName, mkInternalName,
                          localiseName, isExternalName, nameSrcLoc, nameParent_maybe,
                          isWiredInName, getName
@@ -451,9 +451,10 @@ addExternal (id,rhs) needed
   = extendVarEnv (foldVarSet add_occ needed new_needed_ids)
                 id show_unfold
   where
-    add_occ id needed = extendVarEnv needed id False
+    add_occ id needed | id `elemVarEnv` needed = needed
+                     | otherwise              = extendVarEnv needed id False
        -- "False" because we don't know we need the Id's unfolding
-       -- We'll override it later when we find the binding site
+       -- Don't override existing bindings; we might have already set it to True
 
     new_needed_ids = worker_ids        `unionVarSet`
                     unfold_ids `unionVarSet`
@@ -461,7 +462,7 @@ addExternal (id,rhs) needed
 
     idinfo        = idInfo id
     dont_inline           = isNeverActive (inlinePragInfo idinfo)
-    loop_breaker   = isLoopBreaker (occInfo idinfo)
+    loop_breaker   = isNonRuleLoopBreaker (occInfo idinfo)
     bottoming_fn   = isBottomingSig (newStrictnessInfo idinfo `orElse` topSig)
     spec_ids      = specInfoFreeVars (specInfo idinfo)
     worker_info           = workerInfo idinfo