[commit: ghc] wip/cbv-conv-thunk: Speculative evaluate thunks known to Converge (7e6bb34)

[git at git.haskell.org]

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

On branch  : wip/cbv-conv-thunk
Link       : http://ghc.haskell.org/trac/ghc/changeset/7e6bb343d1550982feec6b3b3255e55676b7f1db/ghc

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

commit 7e6bb343d1550982feec6b3b3255e55676b7f1db
Author: Joachim Breitner <mail at joachim-breitner.de>
Date:   Mon Jan 6 14:12:57 2014 +0000

    Speculative evaluate thunks known to Converge
    
    This is an attempt to use the by-products of nested cpr analysis.


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

7e6bb343d1550982feec6b3b3255e55676b7f1db
 compiler/basicTypes/Demand.lhs  |    7 +++++++
 compiler/basicTypes/Id.lhs      |    7 ++++++-
 compiler/simplCore/Simplify.lhs |    2 +-
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/compiler/basicTypes/Demand.lhs b/compiler/basicTypes/Demand.lhs
index 4fbf3ca..0e7996e 100644
--- a/compiler/basicTypes/Demand.lhs
+++ b/compiler/basicTypes/Demand.lhs
@@ -812,6 +812,10 @@ isBotRes :: DmdResult -> Bool
 isBotRes Diverges = True
 isBotRes _        = False
 
+isConvRes :: DmdResult -> Bool
+isConvRes (Converges {}) = True
+isConvRes _              = False
+
 trimCPRInfo :: Bool -> Bool -> DmdResult -> DmdResult
 trimCPRInfo trim_all trim_sums res
   = trimR res
@@ -1439,6 +1443,9 @@ isNopSig (StrictSig ty) = isNopDmdType ty
 isBottomingSig :: StrictSig -> Bool
 isBottomingSig (StrictSig (DmdType _ _ res)) = isBotRes res
 
+isConvSig :: StrictSig -> Bool
+isConvSig (StrictSig (DmdType _ _ res)) = isConvRes res
+
 nopSig, botSig :: StrictSig
 nopSig = StrictSig nopDmdType
 botSig = StrictSig botDmdType
diff --git a/compiler/basicTypes/Id.lhs b/compiler/basicTypes/Id.lhs
index 50b3641..9ad99f3 100644
--- a/compiler/basicTypes/Id.lhs
+++ b/compiler/basicTypes/Id.lhs
@@ -47,7 +47,7 @@ module Id (
 
         -- ** Predicates on Ids
         isImplicitId, isDeadBinder, 
-        isStrictId,
+        isStrictId, isConvId,
         isExportedId, isLocalId, isGlobalId,
         isRecordSelector, isNaughtyRecordSelector,
         isClassOpId_maybe, isDFunId,
@@ -495,6 +495,11 @@ isStrictId id
            -- Take the best of both strictnesses - old and new               
            (isStrictDmd (idDemandInfo id))
 
+isConvId :: Id -> Bool
+isConvId id
+  = ASSERT2( isId id, text "isConvId: not an id: " <+> ppr id )
+           (isConvSig (idStrictness id))
+
         ---------------------------------
         -- UNFOLDING
 idUnfolding :: Id -> Unfolding
diff --git a/compiler/simplCore/Simplify.lhs b/compiler/simplCore/Simplify.lhs
index 03150c6..422e3d0 100644
--- a/compiler/simplCore/Simplify.lhs
+++ b/compiler/simplCore/Simplify.lhs
@@ -1347,7 +1347,7 @@ simplNonRecE env bndr (rhs, rhs_se) (bndrs, body) cont
                 ; -- pprTrace "preInlineUncond" (ppr bndr <+> ppr rhs) $
                   simplLam (extendIdSubst env bndr (mkContEx rhs_se rhs)) bndrs body cont }
 
-          | isStrictId bndr ->           -- Includes coercions
+          | isStrictId bndr || isConvId bndr ->  -- Includes coercions
             do  { simplExprF (rhs_se `setFloats` env) rhs
                              (StrictBind bndr bndrs body env cont) }