import Outputable
\end{code}
------------------------------------------------------------------------------
-Overview
------------------------------------------------------------------------------
+-- ---------------------------------------------------------------------------
+-- Overview
+-- ---------------------------------------------------------------------------
Most of the contents of this pass used to be in CoreToStg. The
primary goals here are:
coreSatExprFloat (Case scrut bndr alts)
= coreSatExprFloat scrut `thenUs` \ (floats, scrut) ->
mapUs sat_alt alts `thenUs` \ alts ->
- mkCase scrut bndr alts `thenUs` \ expr ->
- returnUs (floats, expr)
+ returnUs (floats, Case scrut bndr alts)
where
sat_alt (con, bs, rhs)
= coreSatAnExpr rhs `thenUs` \ rhs ->
#endif
| isUnLiftedType bndr_rep_ty
= ASSERT( not (isUnboxedTupleType bndr_rep_ty) )
- mkCase rhs bndr [(DEFAULT, [], body)] `thenUs` \ expr' ->
- mkBinds floats expr'
+ mkBinds floats (Case rhs bndr [(DEFAULT, [], body)])
| is_whnf
= if is_strict then
| otherwise -- Not WHNF
= if is_strict then
-- Strict let with non-WHNF rhs
- mkCase rhs bndr [(DEFAULT, [], body)] `thenUs` \ expr' ->
- mkBinds floats expr'
+ mkBinds floats (Case rhs bndr [(DEFAULT, [], body)])
else
-- Lazy let with non-WHNF rhs, so keep the floats in the RHS
mkBinds floats rhs `thenUs` \ new_rhs ->
splitFloats [] = ([], [])
-- -----------------------------------------------------------------------------
--- Making case expressions
--- -----------------------------------------------------------------------------
-
-mkCase scrut bndr alts = returnUs (Case scrut bndr alts) -- ToDo
-
-{-
-mkCase scrut@(App _ _) bndr alts
- = let (f,args) = collectArgs scrut in
-
-
-
-mkCase scrut@(StgPrimApp ParOp _ _) bndr
- (StgPrimAlts tycon _ deflt@(StgBindDefault _))
- = returnUs (StgCase scrut bOGUS_LVs bOGUS_LVs bndr noSRT (StgPrimAlts tycon [] deflt))
-
-mkStgCase (StgPrimApp SeqOp [scrut] _) bndr
- (StgPrimAlts _ _ deflt@(StgBindDefault rhs))
- = mkStgCase scrut_expr new_bndr new_alts
- where
- new_alts | isUnLiftedType scrut_ty = WARN( True, text "mkStgCase" ) mkStgPrimAlts scrut_ty [] deflt
- | otherwise = mkStgAlgAlts scrut_ty [] deflt
- scrut_ty = stgArgType scrut
- new_bndr = setIdType bndr scrut_ty
- -- NB: SeqOp :: forall a. a -> Int#
- -- So bndr has type Int#
- -- But now we are going to scrutinise the SeqOp's argument directly,
- -- so we must change the type of the case binder to match that
- -- of the argument expression e.
-
- scrut_expr = case scrut of
- StgVarArg v -> StgApp v []
- -- Others should not happen because
- -- seq of a value should have disappeared
- StgLitArg l -> WARN( True, text "seq on" <+> ppr l ) StgLit l
-
-mkStgCase scrut bndr alts
- = deStgLam scrut `thenUs` \ scrut' ->
- -- It is (just) possible to get a lambda as a srutinee here
- -- Namely: fromDyn (toDyn ((+1)::Int->Int)) False)
- -- gives: case ...Bool == Int->Int... of
- -- True -> case coerce Bool (\x -> + 1 x) of
- -- True -> ...
- -- False -> ...
- -- False -> ...
- -- The True branch of the outer case will never happen, of course.
-
- returnUs (StgCase scrut' bOGUS_LVs bOGUS_LVs bndr noSRT alts)
--}
-
--------------------------------------------------------------------------
-- Demands
-- -----------------------------------------------------------------------------
live_in_whole_case = live_in_alts `unionVarSet` scrut_lvs
in
returnLne (
- StgCase scrut2 live_in_whole_case live_in_alts bndr' noSRT alts2,
+ mkStgCase scrut2 live_in_whole_case live_in_alts bndr' noSRT alts2,
(scrut_fvs `unionFVInfo` alts_fvs) `minusFVBinders` [bndr],
(alts_escs `minusVarSet` unitVarSet bndr) `unionVarSet` getFVSet scrut_fvs
-- You might think we should have scrut_escs, not (getFVSet scrut_fvs),
= coreToStgExpr rhs `thenLne` \ (rhs2, rhs_fvs, rhs_escs) ->
returnLne (StgBindDefault rhs2, rhs_fvs, rhs_escs)
- mkStgAlgAlts ty alts deflt
- = case alts of
- -- Get the tycon from the data con
- (dc, _, _, _) : _rest
- -> StgAlgAlts (Just (dataConTyCon dc)) alts deflt
-
- -- Otherwise just do your best
- [] -> case splitTyConApp_maybe (repType ty) of
- Just (tc,_) | isAlgTyCon tc
- -> StgAlgAlts (Just tc) alts deflt
- other
- -> StgAlgAlts Nothing alts deflt
-
- mkStgPrimAlts ty alts deflt
- = StgPrimAlts (tyConAppTyCon ty) alts deflt
\end{code}
Lets not only take quite a bit of work, but this is where we convert
Nothing -> False
\end{code}
+\begin{code}
+mkStgCase scrut@(StgPrimApp ParOp _ _) lvs1 lvs2 bndr srt
+ (StgPrimAlts tycon _ deflt@(StgBindDefault _))
+ = StgCase scrut lvs1 lvs2 bndr srt (StgPrimAlts tycon [] deflt)
+
+mkStgCase (StgPrimApp SeqOp [scrut] _) lvs1 lvs2 bndr srt
+ (StgPrimAlts _ _ deflt@(StgBindDefault rhs))
+ = StgCase scrut_expr lvs1 lvs2 new_bndr srt new_alts
+ where
+ new_alts
+ | isUnLiftedType scrut_ty = WARN( True, text "mkStgCase" )
+ mkStgPrimAlts scrut_ty [] deflt
+ | otherwise = mkStgAlgAlts scrut_ty [] deflt
+
+ scrut_ty = stgArgType scrut
+ new_bndr = setIdType bndr scrut_ty
+ -- NB: SeqOp :: forall a. a -> Int#
+ -- So bndr has type Int#
+ -- But now we are going to scrutinise the SeqOp's argument directly,
+ -- so we must change the type of the case binder to match that
+ -- of the argument expression e.
+
+ scrut_expr = case scrut of
+ StgVarArg v -> StgApp v []
+ -- Others should not happen because
+ -- seq of a value should have disappeared
+ StgLitArg l -> WARN( True, text "seq on" <+> ppr l ) StgLit l
+
+mkStgCase scrut lvs1 lvs2 bndr srt alts
+ = StgCase scrut lvs1 lvs2 bndr srt alts
+
+
+mkStgAlgAlts ty alts deflt
+ = case alts of
+ -- Get the tycon from the data con
+ (dc, _, _, _) : _rest
+ -> StgAlgAlts (Just (dataConTyCon dc)) alts deflt
+
+ -- Otherwise just do your best
+ [] -> case splitTyConApp_maybe (repType ty) of
+ Just (tc,_) | isAlgTyCon tc
+ -> StgAlgAlts (Just tc) alts deflt
+ other
+ -> StgAlgAlts Nothing alts deflt
+
+mkStgPrimAlts ty alts deflt
+ = StgPrimAlts (tyConAppTyCon ty) alts deflt
+\end{code}
+
Applications:
\begin{code}
projects / ghc-hetmet.git / commitdiff