[commit: ghc] wip/nested-cpr: Revert "deferType forgets CPR info" (42e19b5)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/nested-cpr
Link       : http://ghc.haskell.org/trac/ghc/changeset/42e19b5839f8d8024829207a607015e0402a0d36/ghc

>---------------------------------------------------------------

commit 42e19b5839f8d8024829207a607015e0402a0d36
Author: Joachim Breitner <mail at joachim-breitner.de>
Date:   Thu Nov 28 18:04:45 2013 +0000

    Revert "deferType forgets CPR info"
    
    This reverts commit b7eab1c313c463f0f0849b22d6de954cd6aa35f6.


>---------------------------------------------------------------

42e19b5839f8d8024829207a607015e0402a0d36
 compiler/basicTypes/Demand.lhs |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/compiler/basicTypes/Demand.lhs b/compiler/basicTypes/Demand.lhs
index 561a43f..9cddcb5 100644
--- a/compiler/basicTypes/Demand.lhs
+++ b/compiler/basicTypes/Demand.lhs
@@ -1173,11 +1173,15 @@ deferAndUse False One  ty = ty
 
 deferType :: DmdType -> DmdType
 -- Ie it might be used, or not 
-deferType (DmdType fv _ _) = DmdType (deferEnv fv) [] topRes
+deferType (DmdType fv _ r) = DmdType (deferEnv fv) [] (deferResult r)
 
 deferEnv :: DmdEnv -> DmdEnv
 deferEnv fv = mapVarEnv deferDmd fv
 
+deferResult :: DmdResult -> DmdResult
+deferResult Diverges = topRes  -- Kill outer divergence
+deferResult r        = r       -- Preserve CPR info
+
 useType :: DmdType -> DmdType
 -- useType ty1 == ty1 `bothType` ty1
 -- NB that bothType is assymetrical, so no-op on argument demands