From 7ac0808979534a94617c3391503c961d1ef72755 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 12 Mar 2010 09:39:23 +0100 Subject: Evaluate element/2 at compile-time using type information The erl_expand_records compiler pass translates the following code: h(X) when X#r1.a =:= 1 -> ok. to (essentially): h({r1,V1,V2}=X) when element(2, X) =:= 1 -> ok. Since the guard can only be executed when the pattern matching has succeeded, we know that the second element in the tuple X must have been bound to V2. Thus we can eliminate the call to element/2 like this: h({r1,V1,V2}=X) when V1 =:= 1 -> ok. --- lib/compiler/src/sys_core_fold.erl | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) (limited to 'lib/compiler/src') diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 6202f07479..3e572d4b27 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1194,19 +1194,22 @@ eval_element(Call, #c_literal{val=Pos}, #c_tuple{es=Es}, _Types) when is_integer true -> eval_failure(Call, badarg) end; -%% eval_element(Call, #c_literal{val=Pos}, #c_var{name=V}, Types) -%% when is_integer(Pos) -> -%% case orddict:find(V, Types#sub.t) of -%% {ok,#c_tuple{es=Elements}} -> -%% if -%% 1 =< Pos, Pos =< length(Elements) -> -%% lists:nth(Pos, Elements); -%% true -> -%% eval_failure(Call, badarg) -%% end; -%% error -> -%% Call -%% end; +eval_element(Call, #c_literal{val=Pos}, #c_var{name=V}, Types) + when is_integer(Pos) -> + case orddict:find(V, Types#sub.t) of + {ok,#c_tuple{es=Elements}} -> + if + 1 =< Pos, Pos =< length(Elements) -> + case lists:nth(Pos, Elements) of + #c_alias{var=Alias} -> Alias; + Res -> Res + end; + true -> + eval_failure(Call, badarg) + end; + error -> + Call + end; eval_element(Call, Pos, Tuple, _Types) -> case is_not_integer(Pos) orelse is_not_tuple(Tuple) of true -> -- cgit v1.2.3 From 470c91d43eae54f63661645acbce4b92d73287cc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 12 Mar 2010 09:42:40 +0100 Subject: Evaluate is_record/3 at compile-time using type information --- lib/compiler/src/sys_core_fold.erl | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/compiler/src') diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 3e572d4b27..96015fbe58 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1038,6 +1038,8 @@ fold_non_lit_args(Call, lists, append, [Arg1,Arg2], _) -> eval_append(Call, Arg1, Arg2); fold_non_lit_args(Call, erlang, setelement, [Arg1,Arg2,Arg3], _) -> eval_setelement(Call, Arg1, Arg2, Arg3); +fold_non_lit_args(Call, erlang, is_record, [Arg1,Arg2,Arg3], Sub) -> + eval_is_record(Call, Arg1, Arg2, Arg3, Sub); fold_non_lit_args(Call, erlang, N, Args, Sub) -> NumArgs = length(Args), case erl_internal:comp_op(N, NumArgs) of @@ -1218,6 +1220,20 @@ eval_element(Call, Pos, Tuple, _Types) -> Call end. +%% eval_is_record(Call, Var, Tag, Size, Types) -> Val. +%% Evaluates is_record/3 using type information. +%% +eval_is_record(Call, #c_var{name=V}, #c_literal{val=NeededTag}=Lit, + #c_literal{val=Size}, Types) -> + case orddict:find(V, Types#sub.t) of + {ok,#c_tuple{es=[#c_literal{val=Tag}|_]=Es}} -> + Lit#c_literal{val=Tag =:= NeededTag andalso + length(Es) =:= Size}; + _ -> + Call + end; +eval_is_record(Call, _, _, _, _) -> Call. + %% is_not_integer(Core) -> true | false. %% Returns true if Core is definitely not an integer. -- cgit v1.2.3 From e96f49fbba499b56026735a302fbfbdf7524db66 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 12 Mar 2010 10:42:45 +0100 Subject: beam_dead: Combine is_eq_exact instructions into select_val instructions Combine a sequence of chained is_eq_exact instructions into a select_val instruction. --- lib/compiler/src/beam_dead.erl | 48 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 5 deletions(-) (limited to 'lib/compiler/src') diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index 7b4cd814a2..e690d1b96b 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -281,12 +281,12 @@ forward([{test,is_eq_exact,_,[Dst,Src]}=I,{move,Src,Dst}|Is], D, Lc, Acc) -> forward([I|Is], D, Lc, Acc); forward([{test,is_nil,_,[Dst]}=I,{move,nil,Dst}|Is], D, Lc, Acc) -> forward([I|Is], D, Lc, Acc); -forward([{test,is_eq_exact,_,[_,{atom,_}]}=I|Is], D, Lc, [{label,_}|_]=Acc) -> +forward([{test,is_eq_exact,_,_}=I|Is], D, Lc, Acc) -> case Is of [{label,_}|_] -> forward(Is, D, Lc, [I|Acc]); _ -> forward(Is, D, Lc+1, [{label,Lc},I|Acc]) end; -forward([{test,is_ne_exact,_,[_,{atom,_}]}=I|Is], D, Lc, [{label,_}|_]=Acc) -> +forward([{test,is_ne_exact,_,_}=I|Is], D, Lc, Acc) -> case Is of [{label,_}|_] -> forward(Is, D, Lc, [I|Acc]); _ -> forward(Is, D, Lc+1, [{label,Lc},I|Acc]) @@ -371,10 +371,10 @@ backward([{test,bs_start_match2,{f,To0},Live,[Src|_]=Info,Dst}|Is], D, Acc) -> To = shortcut_bs_start_match(To0, Src, D), I = {test,bs_start_match2,{f,To},Live,Info,Dst}, backward(Is, D, [I|Acc]); -backward([{test,is_eq_exact=Op,{f,To0},[Reg,{atom,Val}]=Ops}|Is], D, Acc) -> +backward([{test,is_eq_exact,{f,To0},[Reg,{atom,Val}]=Ops}|Is], D, Acc) -> To1 = shortcut_bs_test(To0, Is, D), To = shortcut_fail_label(To1, Reg, Val, D), - I = {test,Op,{f,To},Ops}, + I = combine_eqs(To, Ops, D, Acc), backward(Is, D, [I|Acc]); backward([{test,Op,{f,To0},Ops0}|Is], D, Acc) -> To1 = shortcut_bs_test(To0, Is, D), @@ -394,7 +394,10 @@ backward([{test,Op,{f,To0},Ops0}|Is], D, Acc) -> _Code -> To2 end, - I = {test,Op,{f,To},Ops0}, + I = case Op of + is_eq_exact -> combine_eqs(To, Ops0, D, Acc); + _ -> {test,Op,{f,To},Ops0} + end, backward(Is, D, [I|Acc]); backward([{test,Op,{f,To0},Live,Ops0,Dst}|Is], D, Acc) -> To1 = shortcut_bs_test(To0, Is, D), @@ -519,6 +522,41 @@ bif_to_test(Name, Args, Fail) -> not_possible() -> throw(not_possible). +%% combine_eqs(To, Operands, Acc) -> Instruction. +%% Combine two is_eq_exact instructions or (an is_eq_exact +%% instruction and a select_val instruction) to a select_val +%% instruction if possible. +%% +%% Example: +%% +%% is_eq_exact F1 Reg Lit1 select_val Reg F2 [ Lit1 L1 +%% L1: . Lit2 L2 ] +%% . +%% . ==> +%% . +%% F1: is_eq_exact F2 Reg Lit2 F1: is_eq_exact F2 Reg Lit2 +%% L2: .... L2: +%% +combine_eqs(To, [Reg,{Type,_}=Lit1]=Ops, D, [{label,L1}|_]) + when Type =:= atom; Type =:= integer -> + case beam_utils:code_at(To, D) of + [{test,is_eq_exact,{f,F2},[Reg,{Type,_}=Lit2]}, + {label,L2}|_] when Lit1 =/= Lit2 -> + {select_val,Reg,{f,F2},{list,[Lit1,{f,L1},Lit2,{f,L2}]}}; + [{select_val,Reg,{f,F2},{list,[{Type,_}|_]=List0}}|_] -> + List = remove_from_list(Lit1, List0), + {select_val,Reg,{f,F2},{list,[Lit1,{f,L1}|List]}}; + _Is -> + {test,is_eq_exact,{f,To},Ops} + end; +combine_eqs(To, Ops, _D, _Acc) -> + {test,is_eq_exact,{f,To},Ops}. + +remove_from_list(Lit, [Lit,{f,_}|T]) -> + T; +remove_from_list(Lit, [Val,{f,_}=Fail|T]) -> + [Val,Fail|remove_from_list(Lit, T)]; +remove_from_list(_, []) -> []. %% shortcut_bs_test(TargetLabel, [Instruction], D) -> TargetLabel' %% Try to shortcut the failure label for a bit syntax matching. -- cgit v1.2.3 From 00471858a9be8df38e6c3abde159614feabb8262 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 12 Mar 2010 10:43:36 +0100 Subject: beam_peep: Remove optimization already done by beam_dead --- lib/compiler/src/beam_peep.erl | 48 ++---------------------------------------- 1 file changed, 2 insertions(+), 46 deletions(-) (limited to 'lib/compiler/src') diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl index d03ac4b1f4..a18ad72abf 100644 --- a/lib/compiler/src/beam_peep.erl +++ b/lib/compiler/src/beam_peep.erl @@ -64,22 +64,7 @@ function({function,Name,Arity,CLabel,Is0}) -> %% InEncoding =:= latin1, OutEncoding =:= unicode; %% InEncoding =:= latin1, OutEncoding =:= utf8 -> %% -%% (2) Code like -%% -%% is_ne_exact Fail Reg Literal1 -%% is_ne_exact Fail Reg Literal2 -%% is_ne_exact Fail Reg Literal3 -%% is_eq_exact UltimateFail Reg Literal4 -%% Fail: .... -%% -%% can be rewritten to -%% -%% select_val Reg UltimateFail [ Literal1 Fail -%% Literal2 Fail -%% Literal3 Fail -%% Literal4 Fail ] -%% -%% (3) A select_val/4 instruction that only verifies that +%% (2) A select_val/4 instruction that only verifies that %% its argument is either 'true' or 'false' can be %% be replaced with an is_boolean/2 instruction. That is: %% @@ -132,7 +117,7 @@ peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) -> false -> %% Remember that we have seen this test. SeenTests = gb_sets:insert(Test, SeenTests0), - make_select_val(I, Is, SeenTests, Acc) + peep(Is, SeenTests, [I|Acc]) end end; peep([{select_val,Src,Fail, @@ -151,33 +136,6 @@ peep([I|Is], _, Acc) -> peep(Is, gb_sets:empty(), [I|Acc]); peep([], _, Acc) -> reverse(Acc). -make_select_val({test,is_ne_exact,{f,Fail},[Val,Lit]}=I0, - Is0, SeenTests, Acc) -> - try - Type = case Lit of - {atom,_} -> atom; - {integer,_} -> integer; - _ -> throw(impossible) - end, - {I,Is} = make_select_val_1(Is0, Fail, Val, Type, [Lit,{f,Fail}]), - peep([I|Is], SeenTests, Acc) - catch - impossible -> - peep(Is0, SeenTests, [I0|Acc]) - end; -make_select_val(I, Is, SeenTests, Acc) -> - peep(Is, SeenTests, [I|Acc]). - -make_select_val_1([{test,is_ne_exact,{f,Fail},[Val,{Type,_}=Lit]}|Is], - Fail, Val, Type, Acc) -> - make_select_val_1(Is, Fail, Val, Type, [Lit,{f,Fail}|Acc]); -make_select_val_1([{test,is_eq_exact,{f,UltimateFail},[Val,{Type,_}=Lit]} | - [{label,Fail}|_]=Is], Fail, Val, Type, Acc) -> - Choices = [Lit,{f,Fail}|Acc], - I = {select_val,Val,{f,UltimateFail},{list,Choices}}, - {I,Is}; -make_select_val_1(_Is, _Fail, _Val, _Type, _Acc) -> throw(impossible). - kill_seen(Dst, Seen0) -> gb_sets:from_ordset(kill_seen_1(gb_sets:to_list(Seen0), Dst)). @@ -187,5 +145,3 @@ kill_seen_1([{_,Ops}=Test|T], Dst) -> false -> [Test|kill_seen_1(T, Dst)] end; kill_seen_1([], _) -> []. - - -- cgit v1.2.3