[project @ 2001-09-11 08:18:16 by simonpj]

-----------------------
	More demand-info fixes
	-----------------------

	MERGE WITH STABLE BRANCH

There are a handful of functions in IdInfo that zap the
demand-info stored in an Id.  Alas, they were zapping the
*old* demand-info not the new one.  (The old one is still
there for comparison purposes.)  So we were getting some
spurious warnings and (more seriously) potentially some
incorrect strictness.  Easily fixed though.

diff --git a/ghc/compiler/basicTypes/IdInfo.lhs b/ghc/compiler/basicTypes/IdInfo.lhs
index 36fef2f..d2be7f9 100644 (file)
--- a/ghc/compiler/basicTypes/IdInfo.lhs
+++ b/ghc/compiler/basicTypes/IdInfo.lhs
@@ -98,7 +98,7 @@ import Type           ( usOnce, usMany )
 import Demand          hiding( Demand )
 import qualified Demand
 import NewDemand       ( Demand(..), Keepity(..), DmdResult(..),
-                         lazyDmd, topDmd, dmdTypeDepth,
+                         lazyDmd, topDmd, dmdTypeDepth, isStrictDmd,
                          StrictSig, mkStrictSig, mkTopDmdType
                        )
 import Outputable      
@@ -289,7 +289,7 @@ setStrictnessInfo info st = st `seq` info { strictnessInfo = st }
        -- Try to avoid spack leaks by seq'ing
 
 setUnfoldingInfo  info uf 
-  | isEvaldUnfolding uf && isStrict (demandInfo info)
+  | isEvaldUnfolding uf
        -- If the unfolding is a value, the demand info may
        -- go pear-shaped, so we nuke it.  Example:
        --      let x = (a,b) in
@@ -299,7 +299,7 @@ setUnfoldingInfo  info uf
        --      let x = (a,b) in h a b x
        -- and now x is not demanded (I'm assuming h is lazy)
        -- This really happens.  The solution here is a bit ad hoc...
-  = info { unfoldingInfo = uf, demandInfo = wwLazy }
+  = info { unfoldingInfo = uf, newDemandInfo = Lazy }
 
   | otherwise
        -- We do *not* seq on the unfolding info, For some reason, doing so 
@@ -754,12 +754,12 @@ part of an unsaturated lambda
 
 \begin{code}
 zapLamInfo :: IdInfo -> Maybe IdInfo
-zapLamInfo info@(IdInfo {occInfo = occ, demandInfo = demand})
-  | is_safe_occ && not (isStrict demand)
+zapLamInfo info@(IdInfo {occInfo = occ, newDemandInfo = demand})
+  | is_safe_occ && not (isStrictDmd demand)
   = Nothing
   | otherwise
   = Just (info {occInfo = safe_occ,
-               demandInfo = wwLazy})
+               newDemandInfo = Lazy})
   where
        -- The "unsafe" occ info is the ones that say I'm not in a lambda
        -- because that might not be true for an unsaturated lambda
@@ -774,9 +774,9 @@ zapLamInfo info@(IdInfo {occInfo = occ, demandInfo = demand})
 
 \begin{code}
 zapDemandInfo :: IdInfo -> Maybe IdInfo
-zapDemandInfo info@(IdInfo {demandInfo = demand})
-  | not (isStrict demand) = Nothing
-  | otherwise            = Just (info {demandInfo = wwLazy})
+zapDemandInfo info@(IdInfo {newDemandInfo = demand})
+  | not (isStrictDmd demand) = Nothing
+  | otherwise               = Just (info {newDemandInfo = Lazy})
 \end{code}