From 86fbd6d76d342906e2a77df877013ea68de73cfb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Thu, 12 Feb 2015 09:22:35 +0100 Subject: sys_core_fold: Strengthen type optimization in lets Make sure that we take extract all possible type information when optimizing a 'let' construct. Since the stronger optimization may generate false warnings, we also need to take special care to suppress false warnings. --- lib/compiler/src/sys_core_fold.erl | 88 ++++++++++++++++++++++++++++-------- lib/compiler/test/warnings_SUITE.erl | 26 +++++++++-- 2 files changed, 93 insertions(+), 21 deletions(-) diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index ea1959d0f8..f0f58c767d 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -2036,7 +2036,7 @@ is_bool_expr(#c_clause{body=B}, Sub) -> is_bool_expr(B, Sub); is_bool_expr(#c_let{vars=[V],arg=Arg,body=B}, Sub0) -> Sub = case is_bool_expr(Arg, Sub0) of - true -> update_types(V, [#c_literal{val=true}], Sub0); + true -> update_types(V, [bool], Sub0); false -> Sub0 end, is_bool_expr(B, Sub); @@ -2272,36 +2272,29 @@ opt_simple_let(#c_let{arg=Arg0}=Let, Ctxt, Sub0) -> opt_simple_let_1(#c_let{vars=Vs0,body=B0}=Let, Arg0, Ctxt, Sub0) -> %% Optimise let and add new substitutions. {Vs,Args,Sub1} = let_substs(Vs0, Arg0, Sub0), - BodySub = case {Vs,Args} of - {[V],[A]} -> - case is_bool_expr(A, Sub0) of - true -> - update_types(V, [#c_literal{val=true}], Sub1); - false -> - Sub1 - end; - {_,_} -> Sub1 - end, + BodySub = update_let_types(Vs, Args, Sub1), B = body(B0, Ctxt, BodySub), Arg = core_lib:make_values(Args), - opt_simple_let_2(Let, Vs, Arg, B, Ctxt, Sub1). + opt_simple_let_2(Let, Vs, Arg, B, B0, Ctxt, Sub1). -opt_simple_let_2(Let0, Vs0, Arg0, Body, Ctxt, Sub) -> +opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> case {Vs0,Arg0,Body} of - {[#c_var{name=N1}],Arg,#c_var{name=N2}} -> + {[#c_var{name=N1}],Arg1,#c_var{name=N2}} -> case N1 =:= N2 of true -> %% let <Var> = Arg in <Var> ==> Arg - Arg; + Arg1; false -> %% let <Var> = Arg in <OtherVar> ==> seq Arg OtherVar + Arg = maybe_suppress_warnings(Arg1, Vs0, PrevBody, Ctxt), expr(#c_seq{arg=Arg,body=Body}, Ctxt, sub_new_preserve_types(Sub)) end; {[],#c_values{es=[]},_} -> %% No variables left. Body; - {_,Arg,#c_literal{}} -> + {Vs,Arg1,#c_literal{}} -> + Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody, Ctxt), E = case Ctxt of effect -> %% Throw away the literal body. @@ -2313,22 +2306,50 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, Ctxt, Sub) -> #c_seq{arg=Arg,body=Body} end, expr(E, Ctxt, sub_new_preserve_types(Sub)); - {Vs,Arg,Body} -> + {Vs,Arg1,Body} -> %% If none of the variables are used in the body, we can %% rewrite the let to a sequence: %% let <Var> = Arg in BodyWithoutVar ==> %% seq Arg BodyWithoutVar case is_any_var_used(Vs, Body) of false -> + Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody, Ctxt), expr(#c_seq{arg=Arg,body=Body}, Ctxt, sub_new_preserve_types(Sub)); true -> - Let1 = Let0#c_let{vars=Vs,arg=Arg,body=Body}, + Let1 = Let0#c_let{vars=Vs,arg=Arg1,body=Body}, Let2 = opt_case_in_let(Let1, Sub), opt_case_in_let_arg(Let2, Ctxt, Sub) end end. +%% maybe_suppress_warnings(Arg, [#c_var{}], PreviousBody, Context) -> Arg' +%% Try to suppress false warnings when a variable is not used. +%% For instance, we don't expect a warning for useless building in: +%% +%% R = #r{}, %No warning expected. +%% R#r.f %Optimization would remove the reference to R. +%% +%% To avoid false warnings, we will check whether the variables were +%% referenced in the original unoptimized code. If they were, we will +%% consider the warning false and suppress it. + +maybe_suppress_warnings(Arg, _, _, effect) -> + %% Don't suppress any warnings in effect context. + Arg; +maybe_suppress_warnings(Arg, Vs, PrevBody, value) -> + case suppress_warning(Arg) of + true -> + Arg; %Already suppressed. + false -> + case is_any_var_used(Vs, PrevBody) of + true -> + cerl:set_ann(Arg, [compiler_generated]); + false -> + Arg + end + end. + move_case_into_arg(#c_case{arg=#c_let{vars=OuterVars0,arg=OuterArg, body=InnerArg0}=Outer, clauses=InnerClauses}=Inner, Sub) -> @@ -2504,8 +2525,37 @@ is_tuple_type(Var, Sub) -> yes_no(true) -> yes; yes_no(false) -> no. +%%% +%%% Update type information. +%%% + +update_let_types(Vs, Args, Sub) when is_list(Args) -> + update_let_types_1(Vs, Args, Sub); +update_let_types(_Vs, _Arg, Sub) -> + %% The argument is a complex expression (such as a 'case') + %% that returns multiple values. + Sub. + +update_let_types_1([#c_var{}=V|Vs], [A|As], Sub0) -> + Sub = update_types_from_expr(V, A, Sub0), + update_let_types_1(Vs, As, Sub); +update_let_types_1([], [], Sub) -> Sub. + +update_types_from_expr(V, Expr, Sub) -> + Type = extract_type(Expr, Sub), + update_types(V, [Type], Sub). + +extract_type(Expr, Sub) -> + case is_bool_expr(Expr, Sub) of + false -> Expr; + true -> bool + end. + %% update_types(Expr, Pattern, Sub) -> Sub' %% Update the type database. + +-spec update_types(cerl:cerl(), [type_info()], sub()) -> sub(). + update_types(Expr, Pat, #sub{t=Tdb0}=Sub) -> Tdb = update_types_1(Expr, Pat, Tdb0), Sub#sub{t=Tdb}. @@ -2525,6 +2575,8 @@ update_types_2(V, [#c_tuple{}=P], Types) -> orddict:store(V, P, Types); update_types_2(V, [#c_literal{val=Bool}], Types) when is_boolean(Bool) -> orddict:store(V, bool, Types); +update_types_2(V, [Type], Types) when is_atom(Type) -> + orddict:store(V, Type, Types); update_types_2(_, _, Types) -> Types. %% kill_types(V, Tdb) -> Tdb' diff --git a/lib/compiler/test/warnings_SUITE.erl b/lib/compiler/test/warnings_SUITE.erl index dcd3910926..d0b7c71be8 100644 --- a/lib/compiler/test/warnings_SUITE.erl +++ b/lib/compiler/test/warnings_SUITE.erl @@ -39,7 +39,7 @@ guard/1,bad_arith/1,bool_cases/1,bad_apply/1, files/1,effect/1,bin_opt_info/1,bin_construction/1, comprehensions/1,maps/1,redundant_boolean_clauses/1, - latin1_fallback/1,underscore/1]). + latin1_fallback/1,underscore/1,no_warnings/1]). % Default timetrap timeout (set in init_per_testcase). -define(default_timeout, ?t:minutes(2)). @@ -65,7 +65,7 @@ groups() -> bad_arith,bool_cases,bad_apply,files,effect, bin_opt_info,bin_construction,comprehensions,maps, redundant_boolean_clauses,latin1_fallback, - underscore]}]. + underscore,no_warnings]}]. init_per_suite(Config) -> Config. @@ -281,7 +281,6 @@ bad_arith(Config) when is_list(Config) -> {3,sys_core_fold,{eval_failure,badarith}}, {9,sys_core_fold,nomatch_guard}, {9,sys_core_fold,{eval_failure,badarith}}, - {9,sys_core_fold,{no_effect,{erlang,is_integer,1}}}, {10,sys_core_fold,nomatch_guard}, {10,sys_core_fold,{eval_failure,badarith}}, {15,sys_core_fold,{eval_failure,badarith}} @@ -719,6 +718,27 @@ underscore(Config) when is_list(Config) -> ok. +no_warnings(Config) when is_list(Config) -> + Ts = [{no_warnings, + <<"-record(r, {s=ordsets:new(),a,b}). + + a() -> + R = #r{}, %No warning expected. + {R#r.a,R#r.b}. + + b(X) -> + T = true, + Var = [X], %No warning expected. + case T of + false -> Var; + true -> [] + end. + ">>, + [], + []}], + run(Config, Ts), + ok. + %%% %%% End of test cases. %%% -- cgit v1.2.3 From 5a6c78379cbbdf945d78a6b9d3c2c8d37db71607 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Thu, 12 Feb 2015 12:47:26 +0100 Subject: Update type information based on BIFs that returns integers --- lib/compiler/src/sys_core_fold.erl | 24 +++++++++++++++++++++++- lib/compiler/test/core_fold_SUITE.erl | 1 + 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index f0f58c767d..570b943a40 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -96,7 +96,7 @@ t=[], %Types in_guard=false}). %In guard or not. --type type_info() :: cerl:cerl() | 'bool'. +-type type_info() :: cerl:cerl() | 'bool' | 'integer'. -type yes_no_maybe() :: 'yes' | 'no' | 'maybe'. -type sub() :: #sub{}. @@ -2511,6 +2511,7 @@ is_boolean_type(Var, Sub) -> is_int_type(Var, Sub) -> case get_type(Var, Sub) of none -> maybe; + integer -> yes; C -> yes_no(cerl:is_c_int(C)) end. @@ -2545,12 +2546,33 @@ update_types_from_expr(V, Expr, Sub) -> Type = extract_type(Expr, Sub), update_types(V, [Type], Sub). +extract_type(#c_call{module=#c_literal{val=erlang}, + name=#c_literal{val=Name}, + args=Args}=Call, Sub) -> + case returns_integer(Name, Args) of + true -> integer; + false -> extract_type_1(Call, Sub) + end; extract_type(Expr, Sub) -> + extract_type_1(Expr, Sub). + +extract_type_1(Expr, Sub) -> case is_bool_expr(Expr, Sub) of false -> Expr; true -> bool end. +returns_integer(bit_size, [_]) -> true; +returns_integer('bsl', [_,_]) -> true; +returns_integer('bsr', [_,_]) -> true; +returns_integer(byte_size, [_]) -> true; +returns_integer(length, [_]) -> true; +returns_integer('rem', [_,_]) -> true; +returns_integer(size, [_]) -> true; +returns_integer(tuple_size, [_]) -> true; +returns_integer(trunc, [_]) -> true; +returns_integer(_, _) -> false. + %% update_types(Expr, Pattern, Sub) -> Sub' %% Update the type database. diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl index 512aada203..9228aa7fd1 100644 --- a/lib/compiler/test/core_fold_SUITE.erl +++ b/lib/compiler/test/core_fold_SUITE.erl @@ -88,6 +88,7 @@ t_element(Config) when is_list(Config) -> {_,_,_}=Tup -> ?line {'EXIT',{badarg,_}} = (catch element(4, Tup)) end, + {'EXIT',{badarg,_}} = (catch element(1, tuple_size(Tuple))), ok. -- cgit v1.2.3 From 5e07cf899d657a787e7d4f32c1ad7f44037a011f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Tue, 3 Feb 2015 18:08:13 +0100 Subject: Replace '==' with '=:=' when both operands are integers '=:=' is a cheaper operation than '==', so we should always use '=:=' if the result will be the same as if '==' were used. --- lib/compiler/src/sys_core_fold.erl | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 570b943a40..b9ce6476c3 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -829,16 +829,16 @@ eval_rel_op(Call, '=:=', [Term,#c_literal{val=true}], Sub) -> maybe -> Call; no -> #c_literal{val=false} end; -eval_rel_op(Call, '==', Ops, _Sub) -> - case is_exact_eq_ok(Ops) of +eval_rel_op(Call, '==', Ops, Sub) -> + case is_exact_eq_ok(Ops, Sub) of true -> Name = #c_literal{anno=cerl:get_ann(Call),val='=:='}, Call#c_call{name=Name}; false -> Call end; -eval_rel_op(Call, '/=', Ops, _Sub) -> - case is_exact_eq_ok(Ops) of +eval_rel_op(Call, '/=', Ops, Sub) -> + case is_exact_eq_ok(Ops, Sub) of true -> Name = #c_literal{anno=cerl:get_ann(Call),val='=/='}, Call#c_call{name=Name}; @@ -847,11 +847,17 @@ eval_rel_op(Call, '/=', Ops, _Sub) -> end; eval_rel_op(Call, _, _, _) -> Call. -is_exact_eq_ok([#c_literal{val=Lit}|_]) -> +is_exact_eq_ok([A,B]=L, Sub) -> + case is_int_type(A, Sub) =:= yes andalso is_int_type(B, Sub) =:= yes of + true -> true; + false -> is_exact_eq_ok_1(L) + end. + +is_exact_eq_ok_1([#c_literal{val=Lit}|_]) -> is_non_numeric(Lit); -is_exact_eq_ok([_|T]) -> - is_exact_eq_ok(T); -is_exact_eq_ok([]) -> false. +is_exact_eq_ok_1([_|T]) -> + is_exact_eq_ok_1(T); +is_exact_eq_ok_1([]) -> false. is_non_numeric([H|T]) -> is_non_numeric(H) andalso is_non_numeric(T); -- cgit v1.2.3 From 03f79ba054b5509a05b164220f7d218d278298df Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Wed, 4 Feb 2015 08:05:09 +0100 Subject: Clean up evaluation of setelement/3 The 'try' ... 'catch' is problematic. Firstly, if no optimization is possible, an exception will always be thrown. Secondly, bugs in the code will go unnoticed. --- lib/compiler/src/sys_core_fold.erl | 40 +++++++++++++++++++---------------- lib/compiler/test/core_fold_SUITE.erl | 1 + 2 files changed, 23 insertions(+), 18 deletions(-) diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index b9ce6476c3..8299c6a415 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1014,28 +1014,32 @@ eval_is_record(Call, _, _, _, _) -> Call. %% eval_setelement(Call, Pos, Tuple, NewVal) -> Core. %% Evaluates setelement/3 if position Pos is an integer -%% the shape of the tuple Tuple is known. +%% and the shape of the tuple Tuple is known. %% -eval_setelement(Call, Pos, Tuple, NewVal) -> - try - eval_setelement_1(Pos, Tuple, NewVal) - catch - error:_ -> - Call - end. - -eval_setelement_1(#c_literal{val=Pos}, #c_tuple{anno=A,es=Es}, NewVal) - when is_integer(Pos) -> - ann_c_tuple(A, eval_setelement_2(Pos, Es, NewVal)); -eval_setelement_1(#c_literal{val=Pos}, #c_literal{anno=A,val=Es0}, NewVal) +eval_setelement(Call, #c_literal{val=Pos}, Tuple, NewVal) when is_integer(Pos) -> - Es = [#c_literal{anno=A,val=E} || E <- tuple_to_list(Es0)], - ann_c_tuple(A, eval_setelement_2(Pos, Es, NewVal)). + case cerl:is_data(Tuple) of + false -> + Call; + true -> + Es0 = case cerl:is_c_tuple(Tuple) of + false -> []; + true -> cerl:tuple_es(Tuple) + end, + if + 1 =< Pos, Pos =< length(Es0) -> + Es = eval_setelement_1(Pos, Es0, NewVal), + cerl:update_c_tuple(Tuple, Es); + true -> + eval_failure(Call, badarg) + end + end; +eval_setelement(Call, _, _, _) -> Call. -eval_setelement_2(1, [_|T], NewVal) -> +eval_setelement_1(1, [_|T], NewVal) -> [NewVal|T]; -eval_setelement_2(Pos, [H|T], NewVal) when Pos > 1 -> - [H|eval_setelement_2(Pos-1, T, NewVal)]. +eval_setelement_1(Pos, [H|T], NewVal) when Pos > 1 -> + [H|eval_setelement_1(Pos-1, T, NewVal)]. %% eval_failure(Call, Reason) -> Core. %% Warn for a call that will fail and replace the call with diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl index 9228aa7fd1..bc82eaf5aa 100644 --- a/lib/compiler/test/core_fold_SUITE.erl +++ b/lib/compiler/test/core_fold_SUITE.erl @@ -107,6 +107,7 @@ setelement(Config) when is_list(Config) -> ?line error = setelement_crash_2({a,b,c,d,e,f}, <<42>>), {'EXIT',{badarg,_}} = (catch setelement(1, not_a_tuple, New)), + {'EXIT',{badarg,_}} = (catch setelement(3, {a,b}, New)), ok. -- cgit v1.2.3 From 4f365a9b80bab48c4478a6910624244f88637bcb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Wed, 11 Feb 2015 07:39:27 +0100 Subject: sys_core_fold: Suppress compiler warnings when evaluating element/2 More aggressive optimizations that we plan to introduce could cause spurious compiler warnings. --- lib/compiler/src/sys_core_fold.erl | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 8299c6a415..68272689c2 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -969,7 +969,7 @@ eval_element(Call, #c_literal{val=Pos}, Tuple, Types) 1 =< Pos, Pos =< length(Es) -> El = lists:nth(Pos, Es), try - pat_to_expr(El) + cerl:set_ann(pat_to_expr(El), [compiler_generated]) catch throw:impossible -> Call -- cgit v1.2.3 From e914206e11b439a5794b7a8c3c527af395609ddd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Wed, 31 Dec 2014 11:11:57 +0100 Subject: sys_core_fold: Improve optimization of 'not' Optimize away 'not' in sys_core_fold instead of in beam_block and beam_dead, as we can do a better job in sys_core_fold. I modified the test suite temporarily to never turn off Core Erlang modifications and looked at the coverage. With the new optimizations active in sys_core_fold, the code in beam_block and beam_dead did not find a single 'not' that it could optimize. That proves that the new optimization is at least as good as the old one. Manually, I could also verify that the new optimization would optimize some variations of 'not' that the old one would not handle. --- lib/compiler/src/beam_block.erl | 19 ------ lib/compiler/src/beam_dead.erl | 16 +---- lib/compiler/src/cerl.erl | 3 +- lib/compiler/src/sys_core_fold.erl | 124 ++++++++++++++++++++++++++++++++++--- lib/compiler/test/andor_SUITE.erl | 12 ++++ 5 files changed, 133 insertions(+), 41 deletions(-) diff --git a/lib/compiler/src/beam_block.erl b/lib/compiler/src/beam_block.erl index 92f09e400c..5216f39296 100644 --- a/lib/compiler/src/beam_block.erl +++ b/lib/compiler/src/beam_block.erl @@ -252,13 +252,6 @@ combine_alloc({_,Ns,Nh1,Init}, {_,nostack,Nh2,[]}) -> %% opt([Instruction]) -> [Instruction] %% Optimize the instruction stream inside a basic block. -opt([{set,[Dst],As,{bif,Bif,Fail}}=I1, - {set,[Dst],[Dst],{bif,'not',Fail}}=I2|Is]) -> - %% Get rid of the 'not' if the operation can be inverted. - case inverse_comp_op(Bif) of - none -> [I1,I2|opt(Is)]; - RevBif -> [{set,[Dst],As,{bif,RevBif,Fail}}|opt(Is)] - end; opt([{set,[X],[X],move}|Is]) -> opt(Is); opt([{set,_,_,{line,_}}=Line1, {set,[D1],[{integer,Idx1},Reg],{bif,element,{f,0}}}=I1, @@ -428,18 +421,6 @@ x_live([{x,N}|Rs], Regs) -> x_live(Rs, Regs bor (1 bsl N)); x_live([_|Rs], Regs) -> x_live(Rs, Regs); x_live([], Regs) -> Regs. -%% inverse_comp_op(Op) -> none|RevOp - -inverse_comp_op('=:=') -> '=/='; -inverse_comp_op('=/=') -> '=:='; -inverse_comp_op('==') -> '/='; -inverse_comp_op('/=') -> '=='; -inverse_comp_op('>') -> '=<'; -inverse_comp_op('<') -> '>='; -inverse_comp_op('>=') -> '<'; -inverse_comp_op('=<') -> '>'; -inverse_comp_op(_) -> none. - %%% %%% Evaluation of constant bit fields. %%% diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index 7cd07dc3be..7f28575a65 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -234,10 +234,8 @@ backward([{select,select_val,Reg,{f,Fail0},List0}|Is], D, Acc) -> Fail = shortcut_bs_test(Fail1, Is, D), Sel = {select,select_val,Reg,{f,Fail},List}, backward(Is, D, [Sel|Acc]); -backward([{jump,{f,To0}},{move,Src0,Reg}|Is], D, Acc) -> - To1 = shortcut_select_label(To0, Reg, Src0, D), - {To,Src} = shortcut_boolean_label(To1, Reg, Src0, D), - Move = {move,Src,Reg}, +backward([{jump,{f,To0}},{move,Src,Reg}=Move|Is], D, Acc) -> + To = shortcut_select_label(To0, Reg, Src, D), Jump = {jump,{f,To}}, case beam_utils:is_killed_at(Reg, To, D) of false -> backward([Move|Is], D, [Jump|Acc]); @@ -330,16 +328,6 @@ shortcut_label(To0, D) -> shortcut_select_label(To, Reg, Lit, D) -> shortcut_rel_op(To, is_ne_exact, [Reg,Lit], D). -shortcut_boolean_label(To0, Reg, {atom,Bool0}=Lit, D) when is_boolean(Bool0) -> - case beam_utils:code_at(To0, D) of - [{line,_},{bif,'not',_,[Reg],Reg},{jump,{f,To}}|_] -> - Bool = {atom,not Bool0}, - {shortcut_select_label(To, Reg, Bool, D),Bool}; - _ -> - {To0,Lit} - end; -shortcut_boolean_label(To, _, Bool, _) -> {To,Bool}. - %% Replace a comparison operator with a test instruction and a jump. %% For example, if we have this code: %% diff --git a/lib/compiler/src/cerl.erl b/lib/compiler/src/cerl.erl index 3d4b9ee0c6..8367a1e19e 100644 --- a/lib/compiler/src/cerl.erl +++ b/lib/compiler/src/cerl.erl @@ -138,7 +138,8 @@ ]). -export_type([c_binary/0, c_bitstr/0, c_call/0, c_clause/0, c_cons/0, c_fun/0, - c_literal/0, c_map/0, c_map_pair/0, c_module/0, c_tuple/0, + c_let/0, c_literal/0, c_map/0, c_map_pair/0, + c_module/0, c_tuple/0, c_values/0, c_var/0, cerl/0, var_name/0]). -include("core_parse.hrl"). diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 68272689c2..dc996dc73f 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1965,6 +1965,107 @@ letify(Bs, Body) -> cerl:ann_c_let(Ann, [V], Val, B) end, Body, Bs). +%% opt_not_in_let(Let) -> Cerl +%% Try to optimize away a 'not' operator in a 'let'. + +-spec opt_not_in_let(cerl:c_let()) -> cerl:cerl(). + +opt_not_in_let(#c_let{vars=[_]=Vs0,arg=Arg0,body=Body0}=Let) -> + case opt_not_in_let(Vs0, Arg0, Body0) of + {[],#c_values{es=[]},Body} -> + Body; + {Vs,Arg,Body} -> + Let#c_let{vars=Vs,arg=Arg,body=Body} + end; +opt_not_in_let(Let) -> Let. + +%% opt_not_in_let(Vs, Arg, Body) -> {Vs',Arg',Body'} +%% Try to optimize away a 'not' operator in a 'let'. + +-spec opt_not_in_let([cerl:c_var()], cerl:cerl(), cerl:cerl()) -> + {[cerl:c_var()],cerl:cerl(),cerl:cerl()}. + +opt_not_in_let([#c_var{name=V}]=Vs0, Arg0, Body0) -> + case cerl:type(Body0) of + call -> + %% let <V> = Expr in not V ==> + %% let <> = <> in notExpr + case opt_not_in_let_1(V, Body0, Arg0) of + no -> + {Vs0,Arg0,Body0}; + {yes,Body} -> + {[],#c_values{es=[]},Body} + end; + 'let' -> + %% let <V> = Expr in let <Var> = not V in Body ==> + %% let <Var> = notExpr in Body + %% V must not be used in Body. + LetArg = cerl:let_arg(Body0), + case opt_not_in_let_1(V, LetArg, Arg0) of + no -> + {Vs0,Arg0,Body0}; + {yes,Arg} -> + LetBody = cerl:let_body(Body0), + case core_lib:is_var_used(V, LetBody) of + true -> + {Vs0,Arg0,Body0}; + false -> + LetVars = cerl:let_vars(Body0), + {LetVars,Arg,LetBody} + end + end; + _ -> + {Vs0,Arg0,Body0} + end; +opt_not_in_let(Vs, Arg, Body) -> + {Vs,Arg,Body}. + +opt_not_in_let_1(V, Call, Body) -> + case Call of + #c_call{module=#c_literal{val=erlang}, + name=#c_literal{val='not'}, + args=[#c_var{name=V}]} -> + opt_not_in_let_2(Body); + _ -> + no + end. + +opt_not_in_let_2(#c_case{clauses=Cs0}=Case) -> + Vars = make_vars([], 1), + Body = #c_call{module=#c_literal{val=erlang}, + name=#c_literal{val='not'}, + args=Vars}, + Cs = [begin + Let = #c_let{vars=Vars,arg=B,body=Body}, + C#c_clause{body=opt_not_in_let(Let)} + end || #c_clause{body=B}=C <- Cs0], + {yes,Case#c_case{clauses=Cs}}; +opt_not_in_let_2(#c_call{}=Call0) -> + invert_call(Call0); +opt_not_in_let_2(_) -> no. + +invert_call(#c_call{module=#c_literal{val=erlang}, + name=#c_literal{val=Name0}, + args=[_,_]}=Call) -> + case inverse_rel_op(Name0) of + no -> no; + Name -> {yes,Call#c_call{name=#c_literal{val=Name}}} + end; +invert_call(#c_call{}) -> no. + +%% inverse_rel_op(Op) -> no | RevOp + +inverse_rel_op('=:=') -> '=/='; +inverse_rel_op('=/=') -> '=:='; +inverse_rel_op('==') -> '/='; +inverse_rel_op('/=') -> '=='; +inverse_rel_op('>') -> '=<'; +inverse_rel_op('<') -> '>='; +inverse_rel_op('>=') -> '<'; +inverse_rel_op('=<') -> '>'; +inverse_rel_op(_) -> no. + + %% opt_case_in_let(LetExpr) -> LetExpr' opt_case_in_let(#c_let{vars=Vs,arg=Arg,body=B}=Let, Sub) -> @@ -2272,19 +2373,28 @@ is_failing_clause(#c_clause{body=B}) -> %% Optimize a let construct that does not contain any lets in %% in its argument. -opt_simple_let(#c_let{arg=Arg0}=Let, Ctxt, Sub0) -> - Arg = body(Arg0, value, Sub0), %This is a body +opt_simple_let(Let0, Ctxt, Sub) -> + case opt_not_in_let(Let0) of + #c_let{}=Let -> + opt_simple_let_0(Let, Ctxt, Sub); + Expr -> + expr(Expr, Ctxt, Sub) + end. + +opt_simple_let_0(#c_let{arg=Arg0}=Let, Ctxt, Sub) -> + Arg = body(Arg0, value, Sub), %This is a body case will_fail(Arg) of true -> Arg; - false -> opt_simple_let_1(Let, Arg, Ctxt, Sub0) + false -> opt_simple_let_1(Let, Arg, Ctxt, Sub) end. opt_simple_let_1(#c_let{vars=Vs0,body=B0}=Let, Arg0, Ctxt, Sub0) -> %% Optimise let and add new substitutions. - {Vs,Args,Sub1} = let_substs(Vs0, Arg0, Sub0), - BodySub = update_let_types(Vs, Args, Sub1), - B = body(B0, Ctxt, BodySub), - Arg = core_lib:make_values(Args), + {Vs1,Args,Sub1} = let_substs(Vs0, Arg0, Sub0), + BodySub = update_let_types(Vs1, Args, Sub1), + B1 = body(B0, Ctxt, BodySub), + Arg1 = core_lib:make_values(Args), + {Vs,Arg,B} = opt_not_in_let(Vs1, Arg1, B1), opt_simple_let_2(Let, Vs, Arg, B, B0, Ctxt, Sub1). opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> diff --git a/lib/compiler/test/andor_SUITE.erl b/lib/compiler/test/andor_SUITE.erl index 3199440d84..4d7f444c4f 100644 --- a/lib/compiler/test/andor_SUITE.erl +++ b/lib/compiler/test/andor_SUITE.erl @@ -370,6 +370,11 @@ combined(Config) when is_list(Config) -> ?line true = ?COMB(false, blurf, true), ?line true = ?COMB(true, true, blurf), + false = simple_comb(false, false), + false = simple_comb(false, true), + false = simple_comb(true, false), + true = simple_comb(true, true), + ok. -undef(COMB). @@ -396,6 +401,13 @@ comb(A, B, C) -> end, id(Res). +simple_comb(A, B) -> + %% Use Res twice, to ensure that a careless optimization of 'not' + %% doesn't leave Res as a free variable. + Res = A andalso B, + _ = id(not Res), + Res. + %% Test that a boolean expression in a case expression is properly %% optimized (in particular, that the error behaviour is correct). in_case(Config) when is_list(Config) -> -- cgit v1.2.3 From 0a0d39d351fc2008447bb4a5e22e48f429fe4d93 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Tue, 10 Feb 2015 17:10:34 +0100 Subject: sys_core_fold: Generalize case optimization For a long time, there has been an optimization for: {V1,V2,...} = case Expr of Pat -> ... {Val1,Val2,...}; ... end that avoids building the tuples. The construct looks like this in Core Erlang: let <V> = case X of Pattern -> {Y,Z} end in case V of {A,B} -> A+B end The current optimization will try to replace the second 'case' with a 'let': let <A,B> = case X of Pattern -> <Y,Z> end in A+B Simple variations of the construct would prevent the optimizations; for example this one: let <V> = case X of Pattern -> {'ok',Val} end in case V of {ok,Val} -> Val end The problem is that the optimization tries to do too much. By making the optimization do less and have it depend on other optimizations to finish the job, it will become more powerful. Thus we can rewrite the code like this: let <V1,V2> = case X of Pattern -> <'ok',Val> end in let <V> = {V1,V2} in case V of {ok,Val} -> Val end Note that the second case is unchanged. The other optimizations in the sys_core_fold module will optimize the second 'case' and eliminate the building of the tuple. --- lib/compiler/src/sys_core_fold.erl | 220 +++++++++++++++++++++++++------------ 1 file changed, 147 insertions(+), 73 deletions(-) diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index dc996dc73f..0d020578f5 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -297,7 +297,8 @@ expr(#c_seq{arg=Arg0,body=B0}=Seq0, Ctxt, Sub) -> false -> Seq0#c_seq{arg=Arg,body=B1} end end; -expr(#c_let{}=Let, Ctxt, Sub) -> +expr(#c_let{}=Let0, Ctxt, Sub) -> + Let = opt_case_in_let(Let0), case simplify_let(Let, Sub) of impossible -> %% The argument for the let is "simple", i.e. has no @@ -2066,46 +2067,24 @@ inverse_rel_op('=<') -> '>'; inverse_rel_op(_) -> no. -%% opt_case_in_let(LetExpr) -> LetExpr' +%% opt_bool_case_in_let(LetExpr, Sub) -> Core -opt_case_in_let(#c_let{vars=Vs,arg=Arg,body=B}=Let, Sub) -> - opt_case_in_let_0(Vs, Arg, B, Let, Sub). +opt_bool_case_in_let(#c_let{vars=Vs,arg=Arg,body=B}=Let, Sub) -> + opt_case_in_let_1(Vs, Arg, B, Let, Sub). -opt_case_in_let_0([#c_var{name=V}], Arg, - #c_case{arg=#c_var{name=V},clauses=Cs}=Case, Let, Sub) -> - case opt_case_in_let_1(V, Arg, Cs) of - impossible -> - case is_simple_case_arg(Arg) andalso - not core_lib:is_var_used(V, Case#c_case{arg=#c_literal{val=nil}}) of - true -> - expr(opt_bool_case(Case#c_case{arg=Arg,clauses=Cs}), sub_new(Sub)); - false -> - Let +opt_case_in_let_1([#c_var{name=V}], Arg, + #c_case{arg=#c_var{name=V}}=Case0, Let, Sub) -> + case is_simple_case_arg(Arg) of + true -> + Case = opt_bool_case(Case0#c_case{arg=Arg}), + case core_lib:is_var_used(V, Case) of + false -> expr(Case, sub_new(Sub)); + true -> Let end; - Expr -> Expr + false -> + Let end; -opt_case_in_let_0(_, _, _, Let, _) -> Let. - -opt_case_in_let_1(V, Arg, Cs) -> - try - opt_case_in_let_2(V, Arg, Cs) - catch - _:_ -> impossible - end. - -opt_case_in_let_2(V, Arg0, - [#c_clause{pats=[#c_tuple{es=Es}], - guard=#c_literal{val=true},body=B}|_]) -> - - %% In {V1,V2,...} = case E of P -> ... {Val1,Val2,...}; ... end. - %% avoid building tuples, by converting tuples to multiple values. - %% (The optimisation is not done if the built tuple is used or returned.) - - true = all(fun (#c_var{}) -> true; - (_) -> false end, Es), %Only variables in tuple - false = core_lib:is_var_used(V, B), %Built tuple must not be used. - Arg1 = tuple_to_values(Arg0, length(Es)), %Might fail. - #c_let{vars=Es,arg=Arg1,body=B}. +opt_case_in_let_1(_, _, _, Let, _) -> Let. %% is_simple_case_arg(Expr) -> true|false %% Determine whether the Expr is simple enough to be worth @@ -2233,38 +2212,6 @@ is_safe_bool_expr_list([C|Cs], Sub, BoolVars) -> end; is_safe_bool_expr_list([], _, _) -> true. -%% tuple_to_values(Expr, TupleArity) -> Expr' -%% Convert tuples in return position of arity TupleArity to values. -%% Throws an exception for constructs that are not handled. - -tuple_to_values(#c_tuple{es=Es}, Arity) when length(Es) =:= Arity -> - core_lib:make_values(Es); -tuple_to_values(#c_literal{val=Tuple}=Lit, Arity) when tuple_size(Tuple) =:= Arity -> - Es = [Lit#c_literal{val=E} || E <- tuple_to_list(Tuple)], - core_lib:make_values(Es); -tuple_to_values(#c_case{clauses=Cs0}=Case, Arity) -> - Cs1 = [tuple_to_values(E, Arity) || E <- Cs0], - Case#c_case{clauses=Cs1}; -tuple_to_values(#c_seq{body=B0}=Seq, Arity) -> - Seq#c_seq{body=tuple_to_values(B0, Arity)}; -tuple_to_values(#c_let{body=B0}=Let, Arity) -> - Let#c_let{body=tuple_to_values(B0, Arity)}; -tuple_to_values(#c_receive{clauses=Cs0,timeout=Timeout,action=A0}=Rec, Arity) -> - Cs = [tuple_to_values(E, Arity) || E <- Cs0], - A = case Timeout of - #c_literal{val=infinity} -> A0; - _ -> tuple_to_values(A0, Arity) - end, - Rec#c_receive{clauses=Cs,action=A}; -tuple_to_values(#c_clause{body=B0}=Clause, Arity) -> - B = tuple_to_values(B0, Arity), - Clause#c_clause{body=B}; -tuple_to_values(Expr, _) -> - case will_fail(Expr) of - true -> Expr; - false -> erlang:error({not_handled,Expr}) - end. - %% simplify_let(Let, Sub) -> Expr | impossible %% If the argument part of an let contains a complex expression, such %% as a let or a sequence, move the original let body into the complex @@ -2291,7 +2238,7 @@ move_let_into_expr(#c_let{vars=InnerVs0,body=InnerBody0}=Inner, Arg = body(Arg0, Sub0), ScopeSub0 = sub_subst_scope(Sub0#sub{t=[]}), {OuterVs,ScopeSub} = pattern_list(OuterVs0, ScopeSub0), - + OuterBody = body(OuterBody0, ScopeSub), {InnerVs,Sub} = pattern_list(InnerVs0, Sub0), @@ -2369,6 +2316,133 @@ move_let_into_expr(_Let, _Expr, _Sub) -> impossible. is_failing_clause(#c_clause{body=B}) -> will_fail(B). +%% opt_case_in_let(Let) -> Let' +%% Try to avoid building tuples that are immediately matched. +%% A common pattern is: +%% +%% {V1,V2,...} = case E of P -> ... {Val1,Val2,...}; ... end +%% +%% In Core Erlang the pattern would look like this: +%% +%% let <V> = case E of +%% ... -> ... {Val1,Val2} +%% ... +%% end, +%% in case V of +%% {A,B} -> ... <use A and B> ... +%% end +%% +%% Rewrite this to: +%% +%% let <V1,V2> = case E of +%% ... -> ... <Val1,Val2> +%% ... +%% end, +%% in +%% let <V> = {V1,V2} +%% in case V of +%% {A,B} -> ... <use A and B> ... +%% end +%% +%% Note that the second 'case' is unchanged. The other optimizations +%% in this module will eliminate the building of the tuple and +%% rewrite the second case to: +%% +%% case <V1,V2> of +%% <A,B> -> ... <use A and B> ... +%% end +%% + +opt_case_in_let(#c_let{vars=Vs,arg=Arg0,body=B}=Let0) -> + case matches_data(Vs, B) of + {yes,TypeSig} -> + case delay_build(Arg0, TypeSig) of + no -> + Let0; + {yes,Vars,Arg,Data} -> + InnerLet = Let0#c_let{arg=Data}, + Let0#c_let{vars=Vars,arg=Arg,body=InnerLet} + end; + no -> + Let0 + end. + +matches_data([#c_var{name=V}], #c_case{arg=#c_var{name=V}, + clauses=[#c_clause{pats=[P]}|_]}) -> + case cerl:is_data(P) of + false -> + no; + true -> + case cerl:data_type(P) of + {atomic,_} -> + no; + Type -> + {yes,{Type,cerl:data_arity(P)}} + end + end; +matches_data(_, _) -> no. + +delay_build(Core, TypeSig) -> + case cerl:is_data(Core) of + true -> no; + false -> delay_build_1(Core, TypeSig) + end. + +delay_build_1(Core0, TypeSig) -> + try delay_build_expr(Core0, TypeSig) of + Core -> + {Type,Arity} = TypeSig, + Vars = make_vars([], Arity), + Data = cerl:ann_make_data([compiler_generated], Type, Vars), + {yes,Vars,Core,Data} + catch + throw:impossible -> + no + end. + +delay_build_cs([#c_clause{body=B0}=C0|Cs], TypeSig) -> + B = delay_build_expr(B0, TypeSig), + C = C0#c_clause{body=B}, + [C|delay_build_cs(Cs, TypeSig)]; +delay_build_cs([], _) -> []. + +delay_build_expr(Core, {Type,Arity}=TypeSig) -> + case cerl:is_data(Core) of + false -> + delay_build_expr_1(Core, TypeSig); + true -> + case {cerl:data_type(Core),cerl:data_arity(Core)} of + {Type,Arity} -> + core_lib:make_values(cerl:data_es(Core)); + {_,_} -> + throw(impossible) + end + end. + +delay_build_expr_1(#c_case{clauses=Cs0}=Case, TypeSig) -> + Cs = delay_build_cs(Cs0, TypeSig), + Case#c_case{clauses=Cs}; +delay_build_expr_1(#c_let{body=B0}=Let, TypeSig) -> + B = delay_build_expr(B0, TypeSig), + Let#c_let{body=B}; +delay_build_expr_1(#c_receive{clauses=Cs0, + timeout=Timeout, + action=A0}=Rec, TypeSig) -> + Cs = delay_build_cs(Cs0, TypeSig), + A = case Timeout of + #c_literal{val=infinity} -> A0; + _ -> delay_build_expr(A0, TypeSig) + end, + Rec#c_receive{clauses=Cs,action=A}; +delay_build_expr_1(#c_seq{body=B0}=Seq, TypeSig) -> + B = delay_build_expr(B0, TypeSig), + Seq#c_seq{body=B}; +delay_build_expr_1(Core, _TypeSig) -> + case will_fail(Core) of + true -> Core; + false -> throw(impossible) + end. + %% opt_simple_let(#c_let{}, Context, Sub) -> CoreTerm %% Optimize a let construct that does not contain any lets in %% in its argument. @@ -2438,7 +2512,7 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> sub_new_preserve_types(Sub)); true -> Let1 = Let0#c_let{vars=Vs,arg=Arg1,body=Body}, - Let2 = opt_case_in_let(Let1, Sub), + Let2 = opt_bool_case_in_let(Let1, Sub), opt_case_in_let_arg(Let2, Ctxt, Sub) end end. @@ -2557,7 +2631,7 @@ move_case_into_arg(_, _) -> %% <> when 'true' -> %% let <Var> = Literal2 in LetBody %% end -%% +%% %% In the worst case, the size of the code could increase. %% In practice, though, substituting the literals into %% LetBody and doing constant folding will decrease the code @@ -2985,7 +3059,7 @@ bsm_ensure_no_partition_after([#c_clause{pats=Ps}|Cs], Pos) -> bsm_problem(P, bin_partition) end; bsm_ensure_no_partition_after([], _) -> ok. - + bsm_could_match_binary(#c_alias{pat=P}) -> bsm_could_match_binary(P); bsm_could_match_binary(#c_cons{}) -> false; bsm_could_match_binary(#c_tuple{}) -> false; -- cgit v1.2.3 From 8997433288cb571f155c509f402d0ba4fdba5025 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Mon, 12 Jan 2015 14:51:23 +0100 Subject: beam_bool: Correct initialized_regs/2 initialized_regs/2 did not handle allocating instructions; instead treating them as any other 'set' instruction. The consequences could be one or both of the following: Going past the allocating instruction (looking at more instructions) would mean that initialized_regs/2 could return registers that were not actually initialized. That could mean that MustBeKilled in ensure_opt_safe/6 could contain too few registers, and that the code that followed tried to use an uninitialized register. The beam_validator should have detected that problem. Not taking account the number of live registers in the allocating instruction could mean that some registers were not found to be initialized, which could mean that MustBeKilled would contain too many registers. That would mean a missed optimization. --- lib/compiler/src/beam_bool.erl | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lib/compiler/src/beam_bool.erl b/lib/compiler/src/beam_bool.erl index a452d30b61..5ed9c16d61 100644 --- a/lib/compiler/src/beam_bool.erl +++ b/lib/compiler/src/beam_bool.erl @@ -787,6 +787,9 @@ is_not_used(R, Is, Label, #st{ll=Ll}) -> initialized_regs(Is) -> initialized_regs(Is, ordsets:new()). +initialized_regs([{set,Dst,_Src,{alloc,Live,_}}|_], Regs0) -> + Regs = add_init_regs(free_vars_regs(Live), Regs0), + add_init_regs(Dst, Regs); initialized_regs([{set,Dst,Src,_}|Is], Regs) -> initialized_regs(Is, add_init_regs(Dst, add_init_regs(Src, Regs))); initialized_regs([{test,_,_,Src}|Is], Regs) -> -- cgit v1.2.3 From e72e049f25dc001111a6a98ea95a3e7bc3c53c1b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Sun, 11 Jan 2015 15:05:05 +0100 Subject: beam_peep: Optimize away redundant use of is_boolean tests --- lib/compiler/src/beam_peep.erl | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl index 97a8c7ba70..5abacc8d5d 100644 --- a/lib/compiler/src/beam_peep.erl +++ b/lib/compiler/src/beam_peep.erl @@ -108,14 +108,14 @@ peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) -> %% has succeeded. peep(Is, gb_sets:empty(), [I|Acc]); true -> - Test = {Op,Ops}, - case gb_sets:is_element(Test, SeenTests0) of + case is_test_redundant(Op, Ops, SeenTests0) of true -> - %% This test has already succeeded and + %% This test or a similar test has already succeeded and %% is therefore redundant. peep(Is, SeenTests0, Acc); false -> %% Remember that we have seen this test. + Test = {Op,Ops}, SeenTests = gb_sets:insert(Test, SeenTests0), peep(Is, SeenTests, [I|Acc]) end @@ -136,6 +136,15 @@ peep([I|Is], _, Acc) -> peep(Is, gb_sets:empty(), [I|Acc]); peep([], _, Acc) -> reverse(Acc). +is_test_redundant(Op, Ops, Seen) -> + gb_sets:is_element({Op,Ops}, Seen) orelse + is_test_redundant_1(Op, Ops, Seen). + +is_test_redundant_1(is_boolean, [R], Seen) -> + gb_sets:is_element({is_eq_exact,[R,{atom,false}]}, Seen) orelse + gb_sets:is_element({is_eq_exact,[R,{atom,true}]}, Seen); +is_test_redundant_1(_, _, _) -> false. + kill_seen(Dst, Seen0) -> gb_sets:from_ordset(kill_seen_1(gb_sets:to_list(Seen0), Dst)). -- cgit v1.2.3 From d922184dcb5b159b0ff9052d99990dc23b36dc17 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Sun, 8 Feb 2015 10:48:18 +0100 Subject: beam_dead: Optimize Var =:= Var --- lib/compiler/src/beam_dead.erl | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index 7f28575a65..d00264eb6e 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -124,6 +124,8 @@ forward([{label,Lbl}=LblI|[{move,Lit,Dst}|Is1]=Is0], D, Lc, Acc) -> _ -> Is0 %Keep move instruction. end, forward(Is, D, Lc, [LblI|Acc]); +forward([{test,is_eq_exact,_,[Same,Same]}|Is], D, Lc, Acc) -> + forward(Is, D, Lc, Acc); forward([{test,is_eq_exact,_,[Dst,Src]}=I, {block,[{set,[Dst],[Src],move}|Bl]}|Is], D, Lc, Acc) -> forward([I,{block,Bl}|Is], D, Lc, Acc); -- cgit v1.2.3 From e2ced63dfaf14f38d2a334d51b3ca45030d55e0c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Fri, 6 Mar 2015 15:50:45 +0100 Subject: beam_dead: Improve optimization by eliminating fallthroughs --- lib/compiler/src/beam_dead.erl | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index d00264eb6e..f4515ba2a7 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -98,6 +98,12 @@ move_move_into_block([], Acc) -> reverse(Acc). forward(Is, Lc) -> forward(Is, gb_trees:empty(), Lc, []). +forward([{move,_,_}=Move|[{label,L}|_]=Is], D, Lc, Acc) -> + %% move/2 followed by jump/1 is optimized by backward/3. + forward([Move,{jump,{f,L}}|Is], D, Lc, Acc); +forward([{bif,_,_,_,_}=Bif|[{label,L}|_]=Is], D, Lc, Acc) -> + %% bif/4 followed by jump/1 is optimized by backward/3. + forward([Bif,{jump,{f,L}}|Is], D, Lc, Acc); forward([{block,[]}|Is], D, Lc, Acc) -> %% Empty blocks can prevent optimizations. forward(Is, D, Lc, Acc); -- cgit v1.2.3 From 9e15be5f241730b127d89dca01c6ad5f1e7508d7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Fri, 6 Feb 2015 13:22:20 +0100 Subject: v3_core: Teach pat_alias/2 to eliminate duplicated variables Duplicated variables as aliases in patterns, such as: f({_,_}=Dup=Dup) -> ... will work, but produce sub-optimal code similar to: f({_,_}=Dup=NewVar) when Dup =:= NewVar -> ... with one extra guard test for each duplicated variable. Rewrite pat_alias/2 to eliminate all duplicated variables. While we are at it, also simplify handling of tuples, conses, and literals by using the data functions in the cerl module. --- lib/compiler/src/v3_core.erl | 87 +++++++++++++++++++++------------------ lib/compiler/test/match_SUITE.erl | 13 ++++++ 2 files changed, 60 insertions(+), 40 deletions(-) diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl index 3c19a209c0..c954d21e59 100644 --- a/lib/compiler/src/v3_core.erl +++ b/lib/compiler/src/v3_core.erl @@ -78,7 +78,7 @@ splitwith/2,keyfind/3,sort/1,foreach/2,droplast/1,last/1]). -import(ordsets, [add_element/2,del_element/2,is_element/2, union/1,union/2,intersection/2,subtract/2]). --import(cerl, [ann_c_cons/3,ann_c_cons_skel/3,ann_c_tuple/2,c_tuple/1, +-import(cerl, [ann_c_cons/3,ann_c_tuple/2,c_tuple/1, ann_c_map/3]). -include("core_parse.hrl"). @@ -1660,48 +1660,55 @@ pat_segment({bin_element,_,Val,Size,[Type,{unit,Unit}|Flags]}, St) -> %% pat_alias(CorePat, CorePat) -> AliasPat. %% Normalise aliases. Trap bad aliases by throwing 'nomatch'. -pat_alias(#c_var{name=V1}, P2) -> #c_alias{var=#c_var{name=V1},pat=P2}; -pat_alias(P1, #c_var{name=V2}) -> #c_alias{var=#c_var{name=V2},pat=P1}; - -%% alias cons -pat_alias(#c_cons{}=Cons, #c_literal{anno=A,val=[H|T]}=S) -> - pat_alias(Cons, ann_c_cons_skel(A, #c_literal{anno=A,val=H}, - S#c_literal{val=T})); -pat_alias(#c_literal{anno=A,val=[H|T]}=S, #c_cons{}=Cons) -> - pat_alias(ann_c_cons_skel(A, #c_literal{anno=A,val=H}, - S#c_literal{val=T}), Cons); -pat_alias(#c_cons{anno=Anno,hd=H1,tl=T1}, #c_cons{hd=H2,tl=T2}) -> - ann_c_cons(Anno, pat_alias(H1, H2), pat_alias(T1, T2)); - -%% alias tuples -pat_alias(#c_tuple{anno=Anno,es=Es1}, #c_literal{val=T}) when is_tuple(T) -> - Es2 = [#c_literal{val=E} || E <- tuple_to_list(T)], - ann_c_tuple(Anno, pat_alias_list(Es1, Es2)); -pat_alias(#c_literal{anno=Anno,val=T}, #c_tuple{es=Es2}) when is_tuple(T) -> - Es1 = [#c_literal{val=E} || E <- tuple_to_list(T)], - ann_c_tuple(Anno, pat_alias_list(Es1, Es2)); -pat_alias(#c_tuple{anno=Anno,es=Es1}, #c_tuple{es=Es2}) -> - ann_c_tuple(Anno, pat_alias_list(Es1, Es2)); - -%% alias maps -%% There are no literals in maps patterns (patterns are always abstract) -pat_alias(#c_map{es=Es1}=M,#c_map{es=Es2}) -> - M#c_map{es=pat_alias_map_pairs(Es1++Es2)}; - -pat_alias(#c_alias{var=V1,pat=P1}, - #c_alias{var=V2,pat=P2}) -> - if V1 =:= V2 -> #c_alias{var=V1,pat=pat_alias(P1, P2)}; - true -> #c_alias{var=V1,pat=#c_alias{var=V2,pat=pat_alias(P1, P2)}} +pat_alias(#c_var{name=V1}=P, #c_var{name=V1}) -> P; +pat_alias(#c_var{name=V1}=Var, + #c_alias{var=#c_var{name=V2},pat=Pat}=Alias) -> + if + V1 =:= V2 -> + Alias; + true -> + Alias#c_alias{pat=pat_alias(Var, Pat)} + end; +pat_alias(#c_var{}=P1, P2) -> #c_alias{var=P1,pat=P2}; + +pat_alias(#c_alias{var=#c_var{name=V1}}=Alias, #c_var{name=V1}) -> + Alias; +pat_alias(#c_alias{var=#c_var{name=V1}=Var1,pat=P1}, + #c_alias{var=#c_var{name=V2}=Var2,pat=P2}) -> + Pat = pat_alias(P1, P2), + if + V1 =:= V2 -> + #c_alias{var=Var1,pat=Pat}; + true -> + pat_alias(Var1, pat_alias(Var2, Pat)) end; -pat_alias(#c_alias{var=V1,pat=P1}, P2) -> - #c_alias{var=V1,pat=pat_alias(P1, P2)}; -pat_alias(P1, #c_alias{var=V2,pat=P2}) -> - #c_alias{var=V2,pat=pat_alias(P1, P2)}; +pat_alias(#c_alias{var=#c_var{}=Var,pat=P1}, P2) -> + #c_alias{var=Var,pat=pat_alias(P1, P2)}; + +pat_alias(#c_map{es=Es1}=M, #c_map{es=Es2}) -> + M#c_map{es=pat_alias_map_pairs(Es1 ++ Es2)}; + +pat_alias(P1, #c_var{}=Var) -> + #c_alias{var=Var,pat=P1}; +pat_alias(P1, #c_alias{pat=P2}=Alias) -> + Alias#c_alias{pat=pat_alias(P1, P2)}; + pat_alias(P1, P2) -> - case {set_anno(P1, []),set_anno(P2, [])} of - {P,P} -> P; + %% Aliases between binaries are not allowed, so the only + %% legal patterns that remain are data patterns. + case cerl:is_data(P1) andalso cerl:is_data(P2) of + false -> throw(nomatch); + true -> ok + end, + Type = cerl:data_type(P1), + case cerl:data_type(P2) of + Type -> ok; _ -> throw(nomatch) - end. + end, + Es1 = cerl:data_es(P1), + Es2 = cerl:data_es(P2), + Es = pat_alias_list(Es1, Es2), + cerl:make_data(Type, Es). %% pat_alias_list([A1], [A2]) -> [A]. diff --git a/lib/compiler/test/match_SUITE.erl b/lib/compiler/test/match_SUITE.erl index 7522ee985f..9aec0b3d4e 100644 --- a/lib/compiler/test/match_SUITE.erl +++ b/lib/compiler/test/match_SUITE.erl @@ -141,6 +141,13 @@ aliases(Config) when is_list(Config) -> ?line {a,b} = list_alias2([a,b]), ?line {a,b} = list_alias3([a,b]), + %% Non-matching aliases. + none = mixed_aliases(<<42>>), + none = mixed_aliases([b]), + none = mixed_aliases([d]), + none = mixed_aliases({a,42}), + none = mixed_aliases(42), + ok. str_alias(V) -> @@ -244,6 +251,12 @@ list_alias2([X,Y]=[a,b]) -> list_alias3([X,b]=[a,Y]) -> {X,Y}. +mixed_aliases(<<X:8>> = x) -> {a,X}; +mixed_aliases([b] = <<X:8>>) -> {b,X}; +mixed_aliases(<<X:8>> = {a,X}) -> {c,X}; +mixed_aliases([X] = <<X:8>>) -> {d,X}; +mixed_aliases(_) -> none. + %% OTP-7018. match_in_call(Config) when is_list(Config) -> -- cgit v1.2.3 From 0d16828327959cc6a3870474ec7064f6fde9deae Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Wed, 25 Feb 2015 07:39:47 +0100 Subject: Don't inline core_parse Inlining the core_parse module is slow (the inline pass alone takes more than 6 seconds on my computer) and has no benefit. --- lib/compiler/src/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/compiler/src/Makefile b/lib/compiler/src/Makefile index 2032392821..7c4cebdc28 100644 --- a/lib/compiler/src/Makefile +++ b/lib/compiler/src/Makefile @@ -159,6 +159,10 @@ $(EBIN)/beam_asm.beam: $(ESRC)/beam_asm.erl $(EGEN)/beam_opcodes.hrl $(EBIN)/cerl_inline.beam: $(ESRC)/cerl_inline.erl $(V_ERLC) $(ERL_COMPILE_FLAGS) +nowarn_shadow_vars -o$(EBIN) $< +# Inlining core_parse is slow and has no benefit. +$(EBIN)/core_parse.beam: $(EGEN)/core_parse.erl + $(V_ERLC) $(subst +inline,,$(ERL_COMPILE_FLAGS)) -o$(EBIN) $< + # ---------------------------------------------------- # Release Target # ---------------------------------------------------- -- cgit v1.2.3 From 16d02eb264e2ff4c2c7bbe153c0dedc38e4267a5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Thu, 26 Feb 2015 06:36:22 +0100 Subject: v3_codegen: Don't save options in the process dictionary v3_codegen puts the compilation in the process dictionary, but never uses them. --- lib/compiler/src/v3_codegen.erl | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl index cbe50b93b0..fadc40492c 100644 --- a/lib/compiler/src/v3_codegen.erl +++ b/lib/compiler/src/v3_codegen.erl @@ -69,10 +69,8 @@ stk=[], %Stack table res=[]}). %Reserved regs: [{reserved,I,V}] -module({Mod,Exp,Attr,Forms}, Options) -> - put(?MODULE, Options), +module({Mod,Exp,Attr,Forms}, _Options) -> {Fs,St} = functions(Forms, {atom,Mod}), - erase(?MODULE), {ok,{Mod,Exp,Attr,Fs,St#cg.lcount}}. functions(Forms, AtomMod) -> -- cgit v1.2.3 From b4061dfd6ef6f84379fd8a0988eed79cb0bb1972 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Fri, 27 Feb 2015 07:33:57 +0100 Subject: v3_life: Combine literal/2 and literal2/2 For unclear reasons, there are two functions in v3_life that are almost identical: literal/2 and literal2/2. literal/2 is used for expressions and literal2/2 for patterns. It turns out that literal2/2 can do everything that literal/2 can do, except that it transforms maps differently. If we adjust v3_codegen to accept the same format of maps in expressions and patterns, we can rename literal2/2 to literal/2 and use it for expressions and patterns. --- lib/compiler/src/v3_codegen.erl | 2 +- lib/compiler/src/v3_life.erl | 56 +++++++++++------------------------------ 2 files changed, 15 insertions(+), 43 deletions(-) diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl index fadc40492c..7eec9dd62b 100644 --- a/lib/compiler/src/v3_codegen.erl +++ b/lib/compiler/src/v3_codegen.erl @@ -922,7 +922,7 @@ select_extract_tuple(Src, Vs, I, Vdb, Bef, St) -> select_map(Scs, V, Tf, Vf, Bef, St0) -> Reg = fetch_var(V, Bef), {Is,Aft,St1} = - match_fmf(fun(#l{ke={val_clause,{map,_,Es},B},i=I,vdb=Vdb}, Fail, St1) -> + match_fmf(fun(#l{ke={val_clause,{map,exact,_,Es},B},i=I,vdb=Vdb}, Fail, St1) -> select_map_val(V, Es, B, Fail, I, Vdb, Bef, St1) end, Vf, St0, Scs), {[{test,is_map,{f,Tf},[Reg]}|Is],Aft,St1}. diff --git a/lib/compiler/src/v3_life.erl b/lib/compiler/src/v3_life.erl index cd4b5fd674..75bd188479 100644 --- a/lib/compiler/src/v3_life.erl +++ b/lib/compiler/src/v3_life.erl @@ -270,7 +270,7 @@ match(#k_select{anno=A,var=V,types=Kts}, Ls0, I, Ctxt, Vdb0) -> end, Vdb1 = use_vars(union(A#k.us, Ls1), I, Vdb0), Ts = [type_clause(Tc, Ls1, I+1, Ctxt, Vdb1) || Tc <- Kts], - #l{ke={select,literal2(V, Ctxt),Ts},i=I,vdb=Vdb1,a=Anno}; + #l{ke={select,literal(V, Ctxt),Ts},i=I,vdb=Vdb1,a=Anno}; match(#k_guard{anno=A,clauses=Kcs}, Ls, I, Ctxt, Vdb0) -> Vdb1 = use_vars(union(A#k.us, Ls), I, Vdb0), Cs = [guard_clause(G, Ls, I+1, Ctxt, Vdb1) || G <- Kcs], @@ -297,7 +297,7 @@ val_clause(#k_val_clause{anno=A,val=V,body=Kb}, Ls0, I, Ctxt0, Vdb0) -> _ -> Ctxt0 end, B = match(Kb, Ls1, I+1, Ctxt, Vdb1), - #l{ke={val_clause,literal2(V, Ctxt),B},i=I,vdb=use_vars(Bus, I+1, Vdb1),a=A#k.a}. + #l{ke={val_clause,literal(V, Ctxt),B},i=I,vdb=use_vars(Bus, I+1, Vdb1),a=A#k.a}. guard_clause(#k_guard_clause{anno=A,guard=Kg,body=Kb}, Ls, I, Ctxt, Vdb0) -> Vdb1 = use_vars(union(A#k.us, Ls), I+2, Vdb0), @@ -350,6 +350,7 @@ atomic_list(Ks) -> [atomic(K) || K <- Ks]. %% literal_list([Klit]) -> [Lit]. literal(#k_var{name=N}, _) -> {var,N}; +literal(#k_literal{val=I}, _) -> {literal,I}; literal(#k_int{val=I}, _) -> {integer,I}; literal(#k_float{val=F}, _) -> {float,F}; literal(#k_atom{val=N}, _) -> {atom,N}; @@ -358,58 +359,29 @@ literal(#k_nil{}, _) -> nil; literal(#k_cons{hd=H,tl=T}, Ctxt) -> {cons,[literal(H, Ctxt),literal(T, Ctxt)]}; literal(#k_binary{segs=V}, Ctxt) -> - {binary,literal(V, Ctxt)}; + {binary,literal(V, Ctxt)}; +literal(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=[]}, Ctxt) -> + %% Only occurs in patterns. + {bin_seg,Ctxt,literal(S, Ctxt),U,T,Fs,[literal(Seg, Ctxt)]}; literal(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=N}, Ctxt) -> {bin_seg,Ctxt,literal(S, Ctxt),U,T,Fs, [literal(Seg, Ctxt),literal(N, Ctxt)]}; +literal(#k_bin_int{size=S,unit=U,flags=Fs,val=Int,next=N}, Ctxt) -> + %% Only occurs in patterns. + {bin_int,Ctxt,literal(S, Ctxt),U,Fs,Int, + [literal(N, Ctxt)]}; literal(#k_bin_end{}, Ctxt) -> {bin_end,Ctxt}; literal(#k_tuple{es=Es}, Ctxt) -> {tuple,literal_list(Es, Ctxt)}; -literal(#k_map{op=Op,var=Var,es=Es}, Ctxt) -> - {map,Op,literal(Var, Ctxt),literal_list(Es, Ctxt)}; +literal(#k_map{op=Op,var=Var,es=Es0}, Ctxt) -> + {map,Op,literal(Var, Ctxt),literal_list(Es0, Ctxt)}; literal(#k_map_pair{key=K,val=V}, Ctxt) -> - {map_pair,literal(K, Ctxt),literal(V, Ctxt)}; -literal(#k_literal{val=V}, _Ctxt) -> - {literal,V}. + {map_pair,literal(K, Ctxt),literal(V, Ctxt)}. literal_list(Ks, Ctxt) -> [literal(K, Ctxt) || K <- Ks]. -literal2(#k_var{name=N}, _) -> {var,N}; -literal2(#k_literal{val=I}, _) -> {literal,I}; -literal2(#k_int{val=I}, _) -> {integer,I}; -literal2(#k_float{val=F}, _) -> {float,F}; -literal2(#k_atom{val=N}, _) -> {atom,N}; -%%literal2(#k_char{val=C}, _) -> {char,C}; -literal2(#k_nil{}, _) -> nil; -literal2(#k_cons{hd=H,tl=T}, Ctxt) -> - {cons,[literal2(H, Ctxt),literal2(T, Ctxt)]}; -literal2(#k_binary{segs=V}, Ctxt) -> - {binary,literal2(V, Ctxt)}; -literal2(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=[]}, Ctxt) -> - {bin_seg,Ctxt,literal2(S, Ctxt),U,T,Fs,[literal2(Seg, Ctxt)]}; -literal2(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=N}, Ctxt) -> - {bin_seg,Ctxt,literal2(S, Ctxt),U,T,Fs, - [literal2(Seg, Ctxt),literal2(N, Ctxt)]}; -literal2(#k_bin_int{size=S,unit=U,flags=Fs,val=Int,next=N}, Ctxt) -> - {bin_int,Ctxt,literal2(S, Ctxt),U,Fs,Int, - [literal2(N, Ctxt)]}; -literal2(#k_bin_end{}, Ctxt) -> - {bin_end,Ctxt}; -literal2(#k_tuple{es=Es}, Ctxt) -> - {tuple,literal_list2(Es, Ctxt)}; -literal2(#k_map{op=Op,es=Es}, Ctxt) -> - {map,Op,literal_list2(Es, Ctxt)}; -literal2(#k_map_pair{key=K,val=V}, Ctxt) -> - {map_pair,literal2(K, Ctxt),literal2(V, Ctxt)}. - -literal_list2(Ks, Ctxt) -> - [literal2(K, Ctxt) || K <- Ks]. - -%% literal_bin(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=N}) -> -%% {bin_seg,literal(S),U,T,Fs,[literal(Seg),literal(N)]} - %% is_gc_bif(Name, Arity) -> true|false %% Determines whether the BIF Name/Arity might do a GC. -- cgit v1.2.3