diff options
Diffstat (limited to 'lib/compiler/src')
-rw-r--r-- | lib/compiler/src/beam_ssa_type.erl | 453 |
1 files changed, 270 insertions, 183 deletions
diff --git a/lib/compiler/src/beam_ssa_type.erl b/lib/compiler/src/beam_ssa_type.erl index 89fa5ce3d7..058e40106c 100644 --- a/lib/compiler/src/beam_ssa_type.erl +++ b/lib/compiler/src/beam_ssa_type.erl @@ -22,13 +22,15 @@ -export([opt/2]). -include("beam_ssa.hrl"). --import(lists, [any/2,droplast/1,foldl/3,last/1,member/2, +-import(lists, [all/2,any/2,droplast/1,foldl/3,last/1,member/2, reverse/1,sort/1]). -define(UNICODE_INT, #t_integer{elements={0,16#10FFFF}}). -record(d, {ds :: #{beam_ssa:var_name():=beam_ssa:b_set()}, - ls :: #{beam_ssa:label():=type_db()}}). + ls :: #{beam_ssa:label():=type_db()}, + sub :: #{beam_ssa:var_name():=beam_ssa:value()} + }). -define(ATOM_SET_SIZE, 5). @@ -60,7 +62,7 @@ opt(Linear, Args) -> arity=0}]}, Defs = maps:from_list([{V,FakeCall#b_set{dst=Var}} || #b_var{name=V}=Var <- Args]), - D = #d{ds=Defs,ls=#{0=>Ts}}, + D = #d{ds=Defs,ls=#{0=>Ts},sub=#{}}, opt_1(Linear, D). opt_1([{L,Blk}|Bs], #d{ls=Ls}=D) -> @@ -71,9 +73,9 @@ opt_1([{L,Blk}|Bs], #d{ls=Ls}=D) -> %% This block is never reached. Discard it. opt_1(Bs, D) end; -opt_1([], _) -> []. +opt_1([], #d{}) -> []. -opt_2(L, #b_blk{is=Is0}=Blk0, Bs, Ts, D0) -> +opt_2(L, #b_blk{is=Is0}=Blk0, Bs, Ts, #d{sub=Sub}=D0) -> case Is0 of [#b_set{op=call,dst=Dst, args=[#b_remote{mod=#b_literal{val=Mod}, @@ -84,7 +86,7 @@ opt_2(L, #b_blk{is=Is0}=Blk0, Bs, Ts, D0) -> %% Rewrite the terminator to a 'ret', and remove %% all type information for this label. That will %% simplify the phi node in the former successor. - Args = [simplify_arg(Arg, Ts) || Arg <- Args0], + Args = simplify_args(Args0, Sub, Ts), I = I0#b_set{args=[Rem|Args]}, Ret = #b_ret{arg=Dst}, Blk = Blk0#b_blk{is=[I],last=Ret}, @@ -98,61 +100,120 @@ opt_2(L, #b_blk{is=Is0}=Blk0, Bs, Ts, D0) -> opt_3(L, Blk0, Bs, Ts, D0) end. -opt_3(L, #b_blk{is=Is0,last=Last0}=Blk0, Bs, Ts0, #d{ds=Ds0,ls=Ls0}=D0) -> - {Is,Ts,Ds} = opt_is(Is0, Ts0, Ds0, Ls0, []), - D1 = D0#d{ds=Ds}, - Last = opt_terminator(Last0, Ts, Ds), +opt_3(L, #b_blk{is=Is0,last=Last0}=Blk0, Bs, Ts0, + #d{ds=Ds0,ls=Ls0,sub=Sub0}=D0) -> + {Is,Ts,Ds,Sub} = opt_is(Is0, Ts0, Ds0, Ls0, Sub0, []), + D1 = D0#d{ds=Ds,sub=Sub}, + Last1 = simplify_terminator(Last0, Sub, Ts), + Last = opt_terminator(Last1, Ts, Ds), D = update_successors(Last, Ts, D1), Blk = Blk0#b_blk{is=Is,last=Last}, [{L,Blk}|opt_1(Bs, D)]. -opt_is([#b_set{op=phi,dst=#b_var{name=Dst},args=Args0}=I0|Is], Ts0, Ds0, Ls, Acc) -> +simplify_terminator(#b_br{bool=Bool}=Br, Sub, Ts) -> + Br#b_br{bool=simplify_arg(Bool, Sub, Ts)}; +simplify_terminator(#b_switch{arg=Arg}=Sw, Sub, Ts) -> + Sw#b_switch{arg=simplify_arg(Arg, Sub, Ts)}; +simplify_terminator(#b_ret{arg=Arg}=Ret, Sub, Ts) -> + Ret#b_ret{arg=simplify_arg(Arg, Sub, Ts)}. + +opt_is([#b_set{op=phi,dst=#b_var{name=Dst},args=Args0}=I0|Is], + Ts0, Ds0, Ls, Sub0, Acc) -> %% Simplify the phi node by removing all predecessor blocks that no %% longer exists or no longer branches to this block. - Args = [P || {_,From}=P <- Args0, maps:is_key(From, Ls)], - I = I0#b_set{args=Args}, - Ts = update_types(I, Ts0, Ds0), - Ds = Ds0#{Dst=>I}, - opt_is(Is, Ts, Ds, Ls, [I|Acc]); -opt_is([#b_set{dst=#b_var{name=Dst}}=I0|Is], Ts0, Ds0, Ls, Acc) -> - I = beam_ssa:normalize(simplify(I0, Ts0)), - Ts = update_types(I, Ts0, Ds0), - Ds = Ds0#{Dst=>I}, - opt_is(Is, Ts, Ds, Ls, [I|Acc]); -opt_is([], Ts, Ds, _Ls, Acc) -> - {reverse(Acc),Ts,Ds}. + Args = [{simplify_arg(Arg, Sub0, Ts0),From} || + {Arg,From} <- Args0, maps:is_key(From, Ls)], + case all_same(Args) of + true -> + %% Eliminate the phi node if there is just one source + %% value or if the values are identical. + [{Val,_}|_] = Args, + Sub = Sub0#{Dst=>Val}, + opt_is(Is, Ts0, Ds0, Ls, Sub, Acc); + false -> + I = I0#b_set{args=Args}, + Ts = update_types(I, Ts0, Ds0), + Ds = Ds0#{Dst=>I}, + opt_is(Is, Ts, Ds, Ls, Sub0, [I|Acc]) + end; +opt_is([#b_set{args=Args0,dst=#b_var{name=Dst}}=I0|Is], + Ts0, Ds0, Ls, Sub0, Acc) -> + Args = simplify_args(Args0, Sub0, Ts0), + I1 = beam_ssa:normalize(I0#b_set{args=Args}), + case simplify(I1, Ts0) of + #b_set{}=I2 -> + I = beam_ssa:normalize(I2), + Ts = update_types(I, Ts0, Ds0), + Ds = Ds0#{Dst=>I}, + opt_is(Is, Ts, Ds, Ls, Sub0, [I|Acc]); + #b_literal{}=Lit -> + Sub = Sub0#{Dst=>Lit}, + opt_is(Is, Ts0, Ds0, Ls, Sub, Acc); + #b_var{}=Var -> + Sub = Sub0#{Dst=>Var}, + opt_is(Is, Ts0, Ds0, Ls, Sub, Acc) + end; +opt_is([], Ts, Ds, _Ls, Sub, Acc) -> + {reverse(Acc),Ts,Ds,Sub}. +simplify(#b_set{op={bif,'and'},args=Args}=I, Ts) -> + case is_safe_bool_op(Args, Ts) of + true -> + case Args of + [_,#b_literal{val=false}=Res] -> Res; + [Res,#b_literal{val=true}] -> Res; + _ -> eval_bif(I, Ts) + end; + false -> + I + end; +simplify(#b_set{op={bif,'or'},args=Args}=I, Ts) -> + case is_safe_bool_op(Args, Ts) of + true -> + case Args of + [Res,#b_literal{val=false}] -> Res; + [_,#b_literal{val=true}=Res] -> Res; + _ -> eval_bif(I, Ts) + end; + false -> + I + end; simplify(#b_set{op={bif,element},args=[#b_literal{val=Index},Tuple]}=I, Ts) -> case t_tuple_size(get_type(Tuple, Ts)) of {_,Size} when is_integer(Index), 1 =< Index, Index =< Size -> I#b_set{op=get_tuple_element,args=[Tuple,#b_literal{val=Index-1}]}; _ -> - I + eval_bif(I, Ts) end; simplify(#b_set{op={bif,hd},args=[List]}=I, Ts) -> case get_type(List, Ts) of cons -> I#b_set{op=get_hd}; _ -> - I + eval_bif(I, Ts) end; simplify(#b_set{op={bif,tl},args=[List]}=I, Ts) -> case get_type(List, Ts) of cons -> I#b_set{op=get_tl}; _ -> - I + eval_bif(I, Ts) end; simplify(#b_set{op={bif,size},args=[Term]}=I, Ts) -> case get_type(Term, Ts) of #t_tuple{} -> - I#b_set{op={bif,tuple_size}}; + simplify(I#b_set{op={bif,tuple_size}}, Ts); + _ -> + eval_bif(I, Ts) + end; +simplify(#b_set{op={bif,tuple_size},args=[Term]}=I, Ts) -> + case get_type(Term, Ts) of + #t_tuple{size=Size,exact=true} -> + #b_literal{val=Size}; _ -> I end; -simplify(#b_set{op={bif,'=='},args=Args0}=I0, Ts) -> - Args = [simplify_arg(Arg, Ts) || Arg <- Args0], - I = I0#b_set{args=Args}, +simplify(#b_set{op={bif,'=='},args=Args}=I, Ts) -> Types = get_types(Args, Ts), EqEq = case {meet(Types),join(Types)} of {none,any} -> true; @@ -164,50 +225,147 @@ simplify(#b_set{op={bif,'=='},args=Args0}=I0, Ts) -> end, case EqEq of true -> - I#b_set{op={bif,'=:='}}; + simplify(I#b_set{op={bif,'=:='}}, Ts); false -> - I + eval_bif(I, Ts) + end; +simplify(#b_set{op={bif,'=:='},args=[Same,Same]}, _Ts) -> + #b_literal{val=true}; +simplify(#b_set{op={bif,'=:='},args=Args}=I, Ts) -> + case meet(get_types(Args, Ts)) of + none -> #b_literal{val=false}; + _ -> eval_bif(I, Ts) end; -simplify(#b_set{op={bif,Op},args=Args0}=I0, Ts) -> - Args = [simplify_arg(Arg, Ts) || Arg <- Args0], - I = I0#b_set{args=Args}, +simplify(#b_set{op={bif,Op},args=Args}=I, Ts) -> Types = get_types(Args, Ts), case is_float_op(Op, Types) of false -> - I; + eval_bif(I, Ts); true -> AnnoArgs = [anno_float_arg(A) || A <- Types], - beam_ssa:add_anno(float_op, AnnoArgs, I) + eval_bif(beam_ssa:add_anno(float_op, AnnoArgs, I), Ts) end; -simplify(#b_set{op=wait_timeout,args=[Timeout0]}=I, Ts) -> - case simplify_arg(Timeout0, Ts) of - #b_literal{val=infinity} -> - I#b_set{op=wait,args=[]}; - Timeout -> - I#b_set{args=[Timeout]} +simplify(#b_set{op=get_tuple_element,args=[Tuple,#b_literal{val=0}]}=I, Ts) -> + case get_type(Tuple, Ts) of + #t_tuple{elements=[First]} -> + #b_literal{val=First}; + #t_tuple{} -> + I end; -simplify(#b_set{op=Op,args=Args0}=I, Ts) -> - Safe = case Op of - call -> true; - put_list -> true; - put_tuple -> true; - _ -> false - end, - case Safe of - true -> - Args = [simplify_arg(Arg, Ts) || Arg <- Args0], - I#b_set{args=Args}; +simplify(#b_set{op=is_nonempty_list,args=[Src]}=I, Ts) -> + case get_type(Src, Ts) of + any -> I; + list -> I; + cons -> #b_literal{val=true}; + _ -> #b_literal{val=false} + end; +simplify(#b_set{op=is_tagged_tuple, + args=[Src,#b_literal{val=Size},#b_literal{val=Tag}]}=I, Ts) -> + case get_type(Src, Ts) of + #t_tuple{exact=true,size=Size,elements=[Tag]} -> + #b_literal{val=true}; + #t_tuple{exact=true,size=ActualSize,elements=[]} -> + if + Size =/= ActualSize -> + #b_literal{val=false}; + true -> + I + end; + #t_tuple{exact=false} -> + I; + any -> + I; + _ -> + #b_literal{val=false} + end; +simplify(#b_set{op=put_list,args=[#b_literal{val=H}, + #b_literal{val=T}]}, _Ts) -> + #b_literal{val=[H|T]}; +simplify(#b_set{op=put_tuple,args=Args}=I, _Ts) -> + case make_literal_list(Args) of + none -> I; + List -> #b_literal{val=list_to_tuple(List)} + end; +simplify(#b_set{op=succeeded,args=[#b_literal{}]}, _Ts) -> + #b_literal{val=true}; +simplify(#b_set{op=wait_timeout,args=[#b_literal{val=infinity}]}=I, _Ts) -> + I#b_set{op=wait,args=[]}; +simplify(I, _Ts) -> I. + +make_literal_list(Args) -> + make_literal_list(Args, []). + +make_literal_list([#b_literal{val=H}|T], Acc) -> + make_literal_list(T, [H|Acc]); +make_literal_list([_|_], _) -> + none; +make_literal_list([], Acc) -> + reverse(Acc). + +is_safe_bool_op(Args, Ts) -> + [T1,T2] = get_types(Args, Ts), + t_is_boolean(T1) andalso t_is_boolean(T2). + +all_same([{H,_}|T]) -> + all(fun({E,_}) -> E =:= H end, T). + +eval_bif(#b_set{op={bif,Bif},args=Args}=I, Ts) -> + Arity = length(Args), + case erl_bifs:is_pure(erlang, Bif, Arity) of false -> - I + I; + true -> + case make_literal_list(Args) of + none -> + case get_types(Args, Ts) of + [any] -> + I; + [Type] -> + case will_succeed(Bif, Type) of + yes -> + #b_literal{val=true}; + no -> + #b_literal{val=false}; + maybe -> + I + end; + _ -> + I + end; + LitArgs -> + try apply(erlang, Bif, LitArgs) of + Val -> #b_literal{val=Val} + catch + error:_ -> I + end + + end end. -simplify_arg(#b_var{}=Arg, Ts) -> - Type = get_type(Arg, Ts), - case get_literal_from_type(Type) of - none -> Arg; - #b_literal{}=Lit -> Lit +simplify_args(Args, Sub, Ts) -> + [simplify_arg(Arg, Sub, Ts) || Arg <- Args]. + +simplify_arg(#b_var{}=Arg0, Sub, Ts) -> + case sub_arg(Arg0, Sub) of + #b_literal{}=LitArg -> + LitArg; + #b_var{}=Arg -> + Type = get_type(Arg, Ts), + case get_literal_from_type(Type) of + none -> Arg; + #b_literal{}=Lit -> Lit + end end; -simplify_arg(Arg, _Ts) -> Arg. +simplify_arg(#b_remote{mod=Mod,name=Name}=Rem, Sub, Ts) -> + Rem#b_remote{mod=simplify_arg(Mod, Sub, Ts), + name=simplify_arg(Name, Sub, Ts)}; +simplify_arg(Arg, _Sub, _Ts) -> Arg. + +sub_arg(#b_var{name=V}=Old, Sub) -> + case Sub of + #{V:=New} -> New; + #{} -> Old + end. is_float_op('-', [float]) -> true; @@ -229,59 +387,48 @@ anno_float_arg(_) -> convert. opt_terminator(#b_br{bool=#b_literal{}}=Br, _Ts, _Ds) -> beam_ssa:normalize(Br); -opt_terminator(#b_br{bool=#b_var{name=V}=Var}=Br, Ts, Ds) -> - BoolType = get_type(Var, Ts), - case get_literal_from_type(BoolType) of - #b_literal{}=BoolLit -> - beam_ssa:normalize(Br#b_br{bool=BoolLit}); - none -> - #{V:=Set} = Ds, - case Set of - #b_set{op={bif,'=:='},args=[Bool,#b_literal{val=true}]} -> - case t_is_boolean(get_type(Bool, Ts)) of - true -> - %% Bool =:= true ==> Bool - simplify_not(Br#b_br{bool=Bool}, Ts, Ds); - false -> - Br - end; - #b_set{} -> - simplify_not(Br, Ts, Ds) - end +opt_terminator(#b_br{bool=#b_var{name=V}}=Br, Ts, Ds) -> + #{V:=Set} = Ds, + case Set of + #b_set{op={bif,'=:='},args=[Bool,#b_literal{val=true}]} -> + case t_is_boolean(get_type(Bool, Ts)) of + true -> + %% Bool =:= true ==> Bool + simplify_not(Br#b_br{bool=Bool}, Ts, Ds); + false -> + Br + end; + #b_set{} -> + simplify_not(Br, Ts, Ds) end; -opt_terminator(#b_switch{arg=V}=Sw0, Ts, Ds) -> +opt_terminator(#b_switch{arg=#b_literal{}}=Sw, _Ts, _Ds) -> + beam_ssa:normalize(Sw); +opt_terminator(#b_switch{arg=#b_var{}=V}=Sw0, Ts, Ds) -> Type = get_type(V, Ts), - case get_literal_from_type(Type) of - #b_literal{}=Lit -> - Sw = Sw0#b_switch{arg=Lit}, - beam_ssa:normalize(Sw); - none -> - case Type of - #t_integer{elements={_,_}=Range} -> - simplify_switch_int(Sw0, Range); - Type -> - case t_is_boolean(Type) of - true -> - case simplify_switch_bool(Sw0, Ts, Ds) of - #b_br{}=Br -> - opt_terminator(Br, Ts, Ds); - Sw -> - beam_ssa:normalize(Sw) - end; - false -> - beam_ssa:normalize(Sw0) - end + case Type of + #t_integer{elements={_,_}=Range} -> + simplify_switch_int(Sw0, Range); + _ -> + case t_is_boolean(Type) of + true -> + case simplify_switch_bool(Sw0, Ts, Ds) of + #b_br{}=Br -> + opt_terminator(Br, Ts, Ds); + Sw -> + beam_ssa:normalize(Sw) + end; + false -> + beam_ssa:normalize(Sw0) end end; -opt_terminator(#b_ret{}=Ret, _Ts, _Ds) -> - Ret. +opt_terminator(#b_ret{}=Ret, _Ts, _Ds) -> Ret. update_successors(#b_br{bool=#b_literal{val=true},succ=S}, Ts, D) -> update_successor(S, Ts, D); -update_successors(#b_br{bool=#b_var{name=V},succ=Succ,fail=Fail}, Ts, D0) -> - D = update_successor(Fail, Ts#{V:=t_atom(false)}, D0), - SuccTs = infer_types(V, Ts, D0), - update_successor(Succ, SuccTs#{V:=t_atom(true)}, D); +update_successors(#b_br{bool=#b_var{}=Bool,succ=Succ,fail=Fail}, Ts, D0) -> + D = update_successor_bool(Bool, false, Fail, Ts, D0), + SuccTs = infer_types(Bool, Ts, D0), + update_successor_bool(Bool, true, Succ, SuccTs, D); update_successors(#b_switch{arg=#b_var{name=V},fail=Fail,list=List}, Ts, D0) -> D = update_successor(Fail, Ts, D0), foldl(fun({Val,S}, A) -> @@ -290,6 +437,16 @@ update_successors(#b_switch{arg=#b_var{name=V},fail=Fail,list=List}, Ts, D0) -> end, D, List); update_successors(#b_ret{}, _Ts, D) -> D. +update_successor_bool(#b_var{name=V}=Var, BoolValue, S, Ts, D) -> + case t_is_boolean(get_type(Var, Ts)) of + true -> + update_successor(S, Ts#{V:=t_atom(BoolValue)}, D); + false -> + %% The `br` terminator is preceeded by an instruction that + %% does not produce a boolean value, such a `new_try_tag`. + update_successor(S, Ts, D) + end. + update_successor(S, Ts0, #d{ls=Ls}=D) -> case Ls of #{S:=Ts1} -> @@ -306,41 +463,8 @@ update_types(#b_set{op=Op,dst=#b_var{name=Dst},args=Args}, Ts, Ds) -> type(phi, Args, Ts, _Ds) -> Types = [get_type(A, Ts) || {A,_} <- Args], join(Types); -type({bif,'=:='}, [Same,Same], _Ts, _Ds) -> - t_atom(true); -type({bif,'=:='}, [_,_]=Args, Ts, _Ds) -> - case get_literals(Args, Ts) of - [#b_literal{val=Lit1},#b_literal{val=Lit2}] -> - t_atom(Lit1 =:= Lit2); - [_,_] -> - case meet(get_types(Args, Ts)) of - none -> t_atom(false); - _ -> t_boolean() - end - end; -type({bif,tuple_size}, [Src], Ts, _Ds) -> - case t_tuple_size(get_type(Src, Ts)) of - {exact,Size} -> - t_integer(Size); - _ -> - t_integer() - end; type({bif,'band'}, Args, Ts, _Ds) -> band_type(Args, Ts); -type({bif,Bif}, [Src]=Args, Ts, _Ds) -> - case get_type(Src, Ts) of - any -> - bif_type(Bif, Args); - Type -> - case will_succeed(Bif, Type) of - yes -> - t_atom(true); - no -> - t_atom(false); - maybe -> - bif_type(Bif, Args) - end - end; type({bif,Bif}, Args, Ts, _Ds) -> case bif_type(Bif, Args) of number -> @@ -392,42 +516,10 @@ type(call, [#b_remote{mod=#b_literal{val=Mod}, false -> any end end; -type(get_tuple_element, [Tuple,#b_literal{val=0}], Ts, _Ds) -> - case get_type(Tuple, Ts) of - #t_tuple{elements=[First]} -> - get_type(#b_literal{val=First}, Ts); - #t_tuple{} -> - any - end; -type(is_nonempty_list, [Src], Ts, _Ds) -> - case get_type(Src, Ts) of - any -> - t_boolean(); - list -> - t_boolean(); - cons -> - t_atom(true); - _ -> - t_atom(false) - end; -type(is_tagged_tuple, [Src,#b_literal{val=Size},#b_literal{val=Tag}], Ts, _Ds) -> - case get_type(Src, Ts) of - #t_tuple{exact=true,size=Size,elements=[Tag]} -> - t_atom(true); - #t_tuple{exact=true,size=ActualSize,elements=[]} -> - if - Size =/= ActualSize -> - t_atom(false); - true -> - t_boolean() - end; - #t_tuple{exact=false} -> - t_boolean(); - any -> - t_boolean(); - _ -> - t_atom(false) - end; +type(is_nonempty_list, [_], _Ts, _Ds) -> + t_boolean(); +type(is_tagged_tuple, [_,#b_literal{},#b_literal{}], _Ts, _Ds) -> + t_boolean(); type(put_map, _Args, _Ts, _Ds) -> map; type(put_list, _Args, _Ts, _Ds) -> @@ -553,7 +645,6 @@ will_succeed(is_list, Type) -> case Type of list -> yes; cons -> yes; - nil -> yes; _ -> no end; will_succeed(is_map, Type) -> @@ -673,12 +764,8 @@ simplify_not(#b_br{bool=#b_var{name=V},succ=Succ,fail=Fail}=Br0, Ts, Ds) -> Br0 end. -get_literals(Values, Ts) -> - [get_literal_from_type(get_type(Val, Ts)) || Val <- Values]. - get_types(Values, Ts) -> [get_type(Val, Ts) || Val <- Values]. - -spec get_type(beam_ssa:value(), type_db()) -> type(). get_type(#b_var{name=V}, Ts) -> @@ -707,7 +794,7 @@ get_type(#b_literal{val=Val}, _Ts) -> any end. -infer_types(V, Ts, #d{ds=Ds}) -> +infer_types(#b_var{name=V}, Ts, #d{ds=Ds}) -> #{V:=#b_set{op=Op,args=Args}} = Ds, Types = infer_type(Op, Args, Ds), meet_types(Types, Ts). @@ -753,7 +840,6 @@ infer_type(_Op, _Args, _Ds) -> %% Note that that the following BIFs are handle elsewhere: %% %% band/2 -%% tuple_size/1 bif_type(abs, [_]) -> number; bif_type(bit_size, [_]) -> t_integer(); @@ -769,6 +855,7 @@ bif_type(node, [_]) -> #t_atom{}; bif_type(round, [_]) -> t_integer(); bif_type(size, [_]) -> t_integer(); bif_type(trunc, [_]) -> t_integer(); +bif_type(tuple_size, [_]) -> t_integer(); bif_type('bnot', [_]) -> t_integer(); bif_type('bor', [_,_]) -> t_integer(); bif_type('bsl', [_,_]) -> t_integer(); |