+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)]
+ = do
+ vscrut <- vectExpr scrut
+ (vty, lty) <- vectAndLiftType ty
+ (vbndr, vbody) <- vectBndrIn bndr (vectExpr body)
+ return $ vCaseDEFAULT vscrut vbndr vty lty vbody
+
+vectAlgCase _tycon _ty_args scrut bndr ty [(DataAlt _, [], body)]
+ = do
+ vscrut <- vectExpr scrut
+ (vty, lty) <- vectAndLiftType ty
+ (vbndr, vbody) <- vectBndrIn bndr (vectExpr body)
+ return $ vCaseDEFAULT vscrut vbndr vty lty vbody
+
+vectAlgCase tycon _ty_args scrut bndr ty [(DataAlt dc, bndrs, body)]
+ = do
+ vect_tc <- maybeV (lookupTyCon tycon)
+ (vty, lty) <- vectAndLiftType ty
+ vexpr <- vectExpr scrut
+ (vbndr, (vbndrs, (vect_body, lift_body)))
+ <- vect_scrut_bndr
+ . vectBndrsIn bndrs
+ $ vectExpr body
+ let (vect_bndrs, lift_bndrs) = unzip vbndrs
+ (vscrut, lscrut, pdata_tc, _arg_tys) <- mkVScrut (vVar vbndr)
+ vect_dc <- maybeV (lookupDataCon dc)
+ let [pdata_dc] = tyConDataCons pdata_tc
+
+ let vcase = mk_wild_case vscrut vty vect_dc vect_bndrs vect_body
+ lcase = mk_wild_case lscrut lty pdata_dc lift_bndrs lift_body
+
+ return $ vLet (vNonRec vbndr vexpr) (vcase, lcase)
+ where
+ vect_scrut_bndr | isDeadBinder bndr = vectBndrNewIn bndr (fsLit "scrut")
+ | otherwise = vectBndrIn bndr
+
+ mk_wild_case expr ty dc bndrs body
+ = mkWildCase expr (exprType expr) ty [(DataAlt dc, bndrs, body)]
+
+vectAlgCase tycon _ty_args scrut bndr ty alts
+ = do
+ vect_tc <- maybeV (lookupTyCon tycon)
+ (vty, lty) <- vectAndLiftType ty
+
+ let arity = length (tyConDataCons vect_tc)
+ sel_ty <- builtin (selTy arity)
+ sel_bndr <- newLocalVar (fsLit "sel") sel_ty
+ let sel = Var sel_bndr
+
+ (vbndr, valts) <- vect_scrut_bndr
+ $ mapM (proc_alt arity sel vty lty) alts'
+ let (vect_dcs, vect_bndrss, lift_bndrss, vbodies) = unzip4 valts
+
+ vexpr <- vectExpr scrut
+ (vect_scrut, lift_scrut, pdata_tc, _arg_tys) <- mkVScrut (vVar vbndr)
+ let [pdata_dc] = tyConDataCons pdata_tc
+
+ let (vect_bodies, lift_bodies) = unzip vbodies
+
+ vdummy <- newDummyVar (exprType vect_scrut)
+ ldummy <- newDummyVar (exprType lift_scrut)
+ let vect_case = Case vect_scrut vdummy vty
+ (zipWith3 mk_vect_alt vect_dcs vect_bndrss vect_bodies)
+
+ lc <- builtin liftingContext
+ lbody <- combinePD vty (Var lc) sel lift_bodies
+ let lift_case = Case lift_scrut ldummy lty
+ [(DataAlt pdata_dc, sel_bndr : concat lift_bndrss,
+ lbody)]
+
+ return . vLet (vNonRec vbndr vexpr)
+ $ (vect_case, lift_case)
+ where
+ vect_scrut_bndr | isDeadBinder bndr = vectBndrNewIn bndr (fsLit "scrut")
+ | otherwise = vectBndrIn bndr
+
+ alts' = sortBy (\(alt1, _, _) (alt2, _, _) -> cmp alt1 alt2) alts
+
+ cmp (DataAlt dc1) (DataAlt dc2) = dataConTag dc1 `compare` dataConTag dc2
+ cmp DEFAULT DEFAULT = EQ
+ cmp DEFAULT _ = LT
+ cmp _ DEFAULT = GT
+ cmp _ _ = panic "vectAlgCase/cmp"
+
+ proc_alt arity sel vty lty (DataAlt dc, bndrs, body)
+ = do
+ vect_dc <- maybeV (lookupDataCon dc)
+ let ntag = dataConTagZ vect_dc
+ tag = mkDataConTag vect_dc
+ fvs = freeVarsOf body `delVarSetList` bndrs
+
+ pick <- builtin (selPick arity)
+ let flags_expr = mkApps pick [sel, tag]
+ flags_var <- newLocalVar (fsLit "flags") (exprType flags_expr)
+ lc <- builtin liftingContext
+ elems <- builtin (selElements arity ntag)
+
+ (vbndrs, vbody)
+ <- vectBndrsIn bndrs
+ . localV
+ $ do
+ binds <- mapM (pack_var (Var lc) (Var flags_var))
+ . filter isLocalId
+ $ varSetElems fvs
+ (ve, le) <- vectExpr body
+ empty <- emptyPD vty
+ return (ve, Case (elems `App` sel) lc lty
+ [(DEFAULT, [], Let (NonRec flags_var flags_expr)
+ $ mkLets (concat binds) le),
+ (LitAlt (mkMachInt 0), [], empty)])
+ let (vect_bndrs, lift_bndrs) = unzip vbndrs
+ return (vect_dc, vect_bndrs, lift_bndrs, vbody)
+
+ proc_alt _ _ _ _ _ = panic "vectAlgCase/proc_alt"
+
+ mk_vect_alt vect_dc bndrs body = (DataAlt vect_dc, bndrs, body)
+
+ pack_var len flags v
+ = do
+ r <- lookupVar v
+ case r of
+ Local (vv, lv) ->
+ do
+ lv' <- cloneVar lv
+ expr <- packPD (idType vv) (Var lv) len flags
+ updLEnv (\env -> env { local_vars = extendVarEnv
+ (local_vars env) v (vv, lv') })
+ return [(NonRec lv' expr)]
+
+ _ -> return []