diff options
Diffstat (limited to 'lib/compiler/src/beam_ssa_type.erl')
-rw-r--r-- | lib/compiler/src/beam_ssa_type.erl | 187 |
1 files changed, 135 insertions, 52 deletions
diff --git a/lib/compiler/src/beam_ssa_type.erl b/lib/compiler/src/beam_ssa_type.erl index 3b5d25efce..5fbb679c6f 100644 --- a/lib/compiler/src/beam_ssa_type.erl +++ b/lib/compiler/src/beam_ssa_type.erl @@ -23,7 +23,8 @@ -include("beam_ssa_opt.hrl"). -import(lists, [all/2,any/2,droplast/1,foldl/3,last/1,member/2, - partition/2,reverse/1,reverse/2,seq/2,sort/1]). + keyfind/3,partition/2,reverse/1,reverse/2, + seq/2,sort/1]). -define(UNICODE_INT, #t_integer{elements={0,16#10FFFF}}). @@ -260,22 +261,33 @@ opt_is([#b_set{op=phi,dst=Dst,args=Args0}=I0|Is], opt_is(Is, Ts, Ds, Fdb, D, Sub0, [I|Acc]) end; opt_is([#b_set{op=call,args=Args0,dst=Dst}=I0|Is], - Ts0, Ds0, Fdb0, D, Sub, Acc) -> - Args = simplify_args(Args0, Sub, Ts0), + Ts0, Ds0, Fdb0, D, Sub0, Acc) -> + Args = simplify_args(Args0, Sub0, Ts0), I1 = beam_ssa:normalize(I0#b_set{args=Args}), - {Ts,Ds,Fdb,I} = opt_call(I1, D, Ts0, Ds0, Fdb0), - case {map_get(Dst, Ts),Is} of - {none,[#b_set{op=succeeded}]} -> + {Ts1,Ds,Fdb,I2} = opt_call(I1, D, Ts0, Ds0, Fdb0), + case {map_get(Dst, Ts1),Is} of + {_,[#b_set{op=succeeded}]} -> %% This call instruction is inside a try/catch %% block. Don't attempt to optimize it. - opt_is(Is, Ts, Ds, Fdb, D, Sub, [I|Acc]); + opt_is(Is, Ts1, Ds, Fdb, D, Sub0, [I2|Acc]); {none,_} -> %% This call never returns. The rest of the %% instructions will not be executed. Ret = #b_ret{arg=Dst}, - {no_return,Ret,reverse(Acc, [I]),Ds,Fdb,Sub}; - _ -> - opt_is(Is, Ts, Ds, Fdb, D, Sub, [I|Acc]) + {no_return,Ret,reverse(Acc, [I2]),Ds,Fdb,Sub0}; + {_,_} -> + case simplify_call(I2) of + #b_set{}=I -> + opt_is(Is, Ts1, Ds, Fdb, D, Sub0, [I|Acc]); + #b_literal{}=Lit -> + Sub = Sub0#{Dst=>Lit}, + Ts = maps:remove(Dst, Ts1), + opt_is(Is, Ts, Ds0, Fdb, D, Sub, Acc); + #b_var{}=Var -> + Ts = maps:remove(Dst, Ts1), + Sub = Sub0#{Dst=>Var}, + opt_is(Is, Ts, Ds0, Fdb, D, Sub, Acc) + end end; opt_is([#b_set{op=succeeded,args=[Arg],dst=Dst}=I], Ts0, Ds0, Fdb, D, Sub0, Acc) -> @@ -328,6 +340,48 @@ opt_is([#b_set{args=Args0,dst=Dst}=I0|Is], opt_is([], Ts, Ds, Fdb, _D, Sub, Acc) -> {reverse(Acc), Ts, Ds, Fdb, Sub}. +simplify_call(#b_set{op=call,args=[#b_remote{}=Rem|Args]}=I) -> + case Rem of + #b_remote{mod=#b_literal{val=Mod}, + name=#b_literal{val=Name}} -> + case erl_bifs:is_pure(Mod, Name, length(Args)) of + true -> + simplify_remote_call(Mod, Name, Args, I); + false -> + I + end; + #b_remote{} -> + I + end; +simplify_call(I) -> I. + +%% Simplify a remote call to a pure BIF. +simplify_remote_call(erlang, '++', [#b_literal{val=[]},Tl], _I) -> + Tl; +simplify_remote_call(Mod, Name, Args0, I) -> + case make_literal_list(Args0) of + none -> + I; + Args -> + %% The arguments are literals. Try to evaluate the BIF. + try apply(Mod, Name, Args) of + Val -> + case cerl:is_literal_term(Val) of + true -> + #b_literal{val=Val}; + false -> + %% The value can't be expressed as a literal + %% (e.g. a pid). + I + end + catch + _:_ -> + %% Failed. Don't bother trying to optimize + %% the call. + I + end + end. + opt_call(#b_set{dst=Dst,args=[#b_local{}=Callee|Args]}=I0, D, Ts0, Ds0, Fdb0) -> {Ts, Ds, I} = opt_local_call(I0, Ts0, Ds0, Fdb0), case Fdb0 of @@ -452,10 +506,19 @@ simplify(#b_set{op={bif,'=='},args=Args}=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) +simplify(#b_set{op={bif,'=:='},args=[A1,_A2]=Args}=I, Ts) -> + [T1,T2] = get_types(Args, Ts), + case meet(T1, T2) of + none -> + #b_literal{val=false}; + _ -> + case {t_is_boolean(T1),T2} of + {true,#t_atom{elements=[true]}} -> + %% Bool =:= true ==> Bool + A1; + {_,_} -> + eval_bif(I, Ts) + end end; simplify(#b_set{op={bif,Op},args=Args}=I, Ts) -> Types = get_types(Args, Ts), @@ -598,41 +661,49 @@ 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{}=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_br{bool=#b_var{}}=Br, Ts, Ds) -> + simplify_not(Br, 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), +opt_terminator(#b_switch{arg=#b_var{}=V}=Sw, Ts, Ds) -> + case get_type(V, Ts) of + any -> + beam_ssa:normalize(Sw); + Type -> + beam_ssa:normalize(opt_switch(Sw, Type, Ts, Ds)) + end; +opt_terminator(#b_ret{}=Ret, _Ts, _Ds) -> Ret. + + +opt_switch(#b_switch{fail=Fail,list=List0}=Sw0, Type, Ts, Ds) -> + List = prune_switch_list(List0, Fail, Type, Ts), + Sw1 = Sw0#b_switch{list=List}, case Type of #t_integer{elements={_,_}=Range} -> - simplify_switch_int(Sw0, Range); - _ -> + simplify_switch_int(Sw1, Range); + #t_atom{elements=[_|_]} -> 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; + #b_br{} = Br = simplify_switch_bool(Sw1, Ts, Ds), + opt_terminator(Br, Ts, Ds); false -> - beam_ssa:normalize(Sw0) - end + simplify_switch_atom(Type, Sw1) + end; + _ -> + Sw1 + end. + +prune_switch_list([{_,Fail}|T], Fail, Type, Ts) -> + prune_switch_list(T, Fail, Type, Ts); +prune_switch_list([{Arg,_}=Pair|T], Fail, Type, Ts) -> + case meet(get_type(Arg, Ts), Type) of + none -> + %% Different types. This value can never match. + prune_switch_list(T, Fail, Type, Ts); + _ -> + [Pair|prune_switch_list(T, Fail, Type, Ts)] end; -opt_terminator(#b_ret{}=Ret, _Ts, _Ds) -> Ret. +prune_switch_list([], _, _, _) -> []. update_successors(#b_br{bool=#b_literal{val=true},succ=S}, Ts, D) -> update_successor(S, Ts, D); @@ -641,8 +712,8 @@ update_successors(#b_br{bool=#b_var{}=Bool,succ=Succ,fail=Fail}, Ts0, D0) -> true -> %% This variable is defined in this block and is only %% referenced by this br terminator. Therefore, there is - %% no need to include the type database passed on to the - %% successors of this block. + %% no need to include it in the type database passed on to + %% the successors of this block. Ts = maps:remove(Bool, Ts0), {SuccTs,FailTs} = infer_types_br(Bool, Ts, D0), D = update_successor(Fail, FailTs, D0), @@ -1029,6 +1100,17 @@ bs_match_type(utf16, _) -> bs_match_type(utf32, _) -> ?UNICODE_INT. +simplify_switch_atom(#t_atom{elements=Atoms}, #b_switch{list=List0}=Sw) -> + case sort([A || {#b_literal{val=A},_} <- List0]) of + Atoms -> + %% All possible atoms are included in the list. The + %% failure label will never be used. + [{_,Fail}|List] = List0, + Sw#b_switch{fail=Fail,list=List}; + _ -> + Sw + end. + simplify_switch_int(#b_switch{list=List0}=Sw, {Min,Max}) -> List1 = sort(List0), Vs = [V || {#b_literal{val=V},_} <- List1], @@ -1073,14 +1155,14 @@ simplify_is_record(I, any, _Size, _Tag, _Ts) -> simplify_is_record(_I, _Type, _Size, _Tag, _Ts) -> #b_literal{val=false}. -simplify_switch_bool(#b_switch{arg=B,list=List0}=Sw, Ts, Ds) -> - List = sort(List0), - case List of - [{#b_literal{val=false},Fail},{#b_literal{val=true},Succ}] -> - simplify_not(#b_br{bool=B,succ=Succ,fail=Fail}, Ts, Ds); - [_|_] -> - Sw - end. +simplify_switch_bool(#b_switch{arg=B,fail=Fail,list=List0}, Ts, Ds) -> + FalseVal = #b_literal{val=false}, + TrueVal = #b_literal{val=true}, + List1 = List0 ++ [{FalseVal,Fail},{TrueVal,Fail}], + {_,FalseLbl} = keyfind(FalseVal, 1, List1), + {_,TrueLbl} = keyfind(TrueVal, 1, List1), + Br = beam_ssa:normalize(#b_br{bool=B,succ=TrueLbl,fail=FalseLbl}), + simplify_not(Br, Ts, Ds). simplify_not(#b_br{bool=#b_var{}=V,succ=Succ,fail=Fail}=Br0, Ts, Ds) -> case Ds of @@ -1094,7 +1176,8 @@ simplify_not(#b_br{bool=#b_var{}=V,succ=Succ,fail=Fail}=Br0, Ts, Ds) -> end; #{} -> Br0 - end. + end; +simplify_not(#b_br{bool=#b_literal{}}=Br, _Ts, _Ds) -> Br. %%% %%% Calculate the set of variables that are only used once in the |