+ (vbndrs, (vrhss, vbody)) <- vectBndrsIn bndrs
+ $ liftM2 (,)
+ (zipWithM vect_rhs bndrs rhss)
+ (vectExpr body)
+ return $ vLet (vRec vbndrs vrhss) vbody
+ where
+ (bndrs, rhss) = unzip bs
+
+ vect_rhs bndr rhs = localV
+ . inBind bndr
+ . liftM snd
+ $ vectPolyExpr (isLoopBreaker $ idOccInfo bndr) rhs
+
+vectExpr e@(_, AnnLam bndr _)
+ | isId bndr = liftM snd $ vectFnExpr True False e
+{-
+onlyIfV (isEmptyVarSet fvs) (vectScalarLam bs $ deAnnotate body)
+ `orElseV` vectLam True fvs bs body
+ where
+ (bs,body) = collectAnnValBinders e
+-}
+
+vectExpr e = cantVectorise "Can't vectorise expression" (ppr $ deAnnotate e)
+
+
+-- | Vectorise an expression with an outer lambda abstraction.
+vectFnExpr
+ :: Bool -- ^ When the RHS of a binding, whether that binding should be inlined.
+ -> Bool -- ^ Whether the binding is a loop breaker.
+ -> CoreExprWithFVs -- ^ Expression to vectorise. Must have an outer `AnnLam`.
+ -> VM (Inline, VExpr)
+
+vectFnExpr inline loop_breaker e@(fvs, AnnLam bndr _)
+ | isId bndr = onlyIfV (isEmptyVarSet fvs)
+ (mark DontInline . vectScalarLam bs $ deAnnotate body)
+ `orElseV` mark inlineMe (vectLam inline loop_breaker fvs bs body)
+ where
+ (bs,body) = collectAnnValBinders e
+
+vectFnExpr _ _ e = mark DontInline $ vectExpr e
+
+mark :: Inline -> VM a -> VM (Inline, a)
+mark b p = do { x <- p; return (b,x) }
+
+
+-- | Vectorise a function where are the args have scalar type, that is Int, Float or Double.
+vectScalarLam
+ :: [Var] -- ^ Bound variables of function.
+ -> CoreExpr -- ^ Function body.
+ -> VM VExpr
+vectScalarLam args body
+ = dtrace (vcat [text "vectScalarLam ", ppr args, ppr body])
+ $ do scalars <- globalScalars
+ onlyIfV (all is_scalar_ty arg_tys
+ && is_scalar_ty res_ty
+ && is_scalar (extendVarSetList scalars args) body
+ && uses scalars body)
+ $ do
+ fn_var <- hoistExpr (fsLit "fn") (mkLams args body) DontInline
+ zipf <- zipScalars arg_tys res_ty
+ clo <- scalarClosure arg_tys res_ty (Var fn_var)
+ (zipf `App` Var fn_var)
+ clo_var <- hoistExpr (fsLit "clo") clo DontInline
+ lclo <- liftPD (Var clo_var)
+ return (Var clo_var, lclo)
+ where
+ arg_tys = map idType args
+ res_ty = exprType body
+
+ is_scalar_ty ty
+ | Just (tycon, []) <- splitTyConApp_maybe ty
+ = tycon == intTyCon
+ || tycon == floatTyCon
+ || tycon == doubleTyCon
+
+ | otherwise = False
+
+ is_scalar vs (Var v) = v `elemVarSet` vs
+ is_scalar _ e@(Lit _) = is_scalar_ty $ exprType e
+ is_scalar vs (App e1 e2) = is_scalar vs e1 && is_scalar vs e2
+ is_scalar _ _ = False
+
+ -- A scalar function has to actually compute something. Without the check,
+ -- we would treat (\(x :: Int) -> x) as a scalar function and lift it to
+ -- (map (\x -> x)) which is very bad. Normal lifting transforms it to
+ -- (\n# x -> x) which is what we want.
+ uses funs (Var v) = v `elemVarSet` funs
+ uses funs (App e1 e2) = uses funs e1 || uses funs e2
+ uses _ _ = False
+
+
+vectLam
+ :: Bool -- ^ When the RHS of a binding, whether that binding should be inlined.
+ -> Bool -- ^ Whether the binding is a loop breaker.
+ -> VarSet -- ^ The free variables in the body.
+ -> [Var] --
+ -> CoreExprWithFVs
+ -> VM VExpr
+
+vectLam inline loop_breaker fvs bs body
+ = dtrace (vcat [ text "vectLam "
+ , text "free vars = " <> ppr fvs
+ , text "binding vars = " <> ppr bs
+ , text "body = " <> ppr (deAnnotate body)])
+
+ $ do tyvars <- localTyVars
+ (vs, vvs) <- readLEnv $ \env ->
+ unzip [(var, vv) | var <- varSetElems fvs
+ , Just vv <- [lookupVarEnv (local_vars env) var]]
+
+ arg_tys <- mapM (vectType . idType) bs
+
+ dtrace (text "arg_tys = " <> ppr arg_tys) $ return ()
+
+ res_ty <- vectType (exprType $ deAnnotate body)
+
+ dtrace (text "res_ty = " <> ppr res_ty) $ return ()
+
+ buildClosures tyvars vvs arg_tys res_ty
+ . hoistPolyVExpr tyvars (maybe_inline (length vs + length bs))
+ $ do
+ lc <- builtin liftingContext
+ (vbndrs, vbody) <- vectBndrsIn (vs ++ bs) (vectExpr body)
+
+ dtrace (text "vbody = " <> ppr vbody) $ return ()
+
+ vbody' <- break_loop lc res_ty vbody
+ return $ vLams lc vbndrs vbody'
+ where
+ maybe_inline n | inline = Inline n
+ | otherwise = DontInline
+
+ break_loop lc ty (ve, le)
+ | loop_breaker
+ = do
+ empty <- emptyPD ty
+ lty <- mkPDataType ty
+ return (ve, mkWildCase (Var lc) intPrimTy lty
+ [(DEFAULT, [], le),
+ (LitAlt (mkMachInt 0), [], empty)])
+
+ | otherwise = return (ve, le)
+
+
+vectTyAppExpr :: CoreExprWithFVs -> [Type] -> VM VExpr
+vectTyAppExpr (_, AnnVar v) tys = vectPolyVar v tys
+vectTyAppExpr e tys = cantVectorise "Can't vectorise expression"
+ (ppr $ deAnnotate e `mkTyApps` tys)
+
+-- We convert
+--
+-- case e :: t of v { ... }
+--
+-- to
+--
+-- V: let v' = e in case v' of _ { ... }
+-- L: let v' = e in case v' `cast` ... of _ { ... }
+--
+-- When lifting, we have to do it this way because v must have the type
+-- [:V(T):] but the scrutinee must be cast to the representation type. We also
+-- have to handle the case where v is a wild var correctly.
+--
+
+-- FIXME: this is too lazy
+vectAlgCase :: TyCon -> [Type] -> CoreExprWithFVs -> Var -> Type
+ -> [(AltCon, [Var], CoreExprWithFVs)]
+ -> VM VExpr
+vectAlgCase _tycon _ty_args scrut bndr ty [(DEFAULT, [], body)]