diff options
Diffstat (limited to 'lib/compiler/src/sys_core_fold.erl')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 600 |
1 files changed, 147 insertions, 453 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 4922953407..d73060fb7e 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1999-2016. All Rights Reserved. +%% Copyright Ericsson AB 1999-2017. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. @@ -71,7 +71,7 @@ -export([module/2,format_error/1]). -import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,all/2,any/2, - reverse/1,reverse/2,member/2,nth/2,flatten/1, + reverse/1,reverse/2,member/2,flatten/1, unzip/1,keyfind/3]). -import(cerl, [ann_c_cons/3,ann_c_map/3,ann_c_tuple/2]). @@ -83,10 +83,11 @@ -ifdef(DEBUG). -define(ASSERT(E), case E of - true -> ok; + true -> + ok; false -> io:format("~p, line ~p: assertion failed\n", [?MODULE,?LINE]), - exit(assertion_failed) + error(assertion_failed) end). -else. -define(ASSERT(E), ignore). @@ -106,7 +107,6 @@ {'ok', cerl:c_module(), [_]}. module(#c_module{defs=Ds0}=Mod, Opts) -> - put(bin_opt_info, member(bin_opt_info, Opts)), put(no_inline_list_funcs, not member(inline_list_funcs, Opts)), case get(new_var_num) of undefined -> put(new_var_num, 0); @@ -115,12 +115,14 @@ module(#c_module{defs=Ds0}=Mod, Opts) -> init_warnings(), Ds1 = [function_1(D) || D <- Ds0], erase(no_inline_list_funcs), - erase(bin_opt_info), {ok,Mod#c_module{defs=Ds1},get_warnings()}. function_1({#c_var{name={F,Arity}}=Name,B0}) -> try - B = expr(B0, value, sub_new()), %This must be a fun! + B = find_fixpoint(fun(Core) -> + %% This must be a fun! + expr(Core, value, sub_new()) + end, B0, 20), {Name,B} catch Class:Error -> @@ -129,6 +131,14 @@ function_1({#c_var{name={F,Arity}}=Name,B0}) -> erlang:raise(Class, Error, Stack) end. +find_fixpoint(_OptFun, Core, 0) -> + Core; +find_fixpoint(OptFun, Core0, Max) -> + case OptFun(Core0) of + Core0 -> Core0; + Core -> find_fixpoint(OptFun, Core, Max-1) + end. + %% body(Expr, Sub) -> Expr. %% body(Expr, Context, Sub) -> Expr. %% No special handling of anything except values. @@ -160,13 +170,23 @@ guard(Expr, Sub) -> %% opt_guard_try(#c_seq{arg=Arg,body=Body0}=Seq) -> Body = opt_guard_try(Body0), - case {Arg,Body} of - {#c_call{module=#c_literal{val=Mod}, - name=#c_literal{val=Name}, - args=Args},#c_literal{val=false}} -> + WillFail = case Body of + #c_call{module=#c_literal{val=erlang}, + name=#c_literal{val=error}, + args=[_]} -> + true; + #c_literal{val=false} -> + true; + _ -> + false + end, + case Arg of + #c_call{module=#c_literal{val=Mod}, + name=#c_literal{val=Name}, + args=Args} when WillFail -> %% We have sequence consisting of a call (evaluated %% for a possible exception and/or side effect only), - %% followed by 'false'. + %% followed by 'false' or a call to error/1. %% Since the sequence is inside a try block that will %% default to 'false' if any exception occurs, not %% evalutating the call will not change the behaviour @@ -181,7 +201,7 @@ opt_guard_try(#c_seq{arg=Arg,body=Body0}=Seq) -> %% be safely removed. Body end; - {_,_} -> + _ -> Seq#c_seq{body=Body} end; opt_guard_try(#c_case{clauses=Cs}=Term) -> @@ -239,7 +259,7 @@ expr(#c_cons{anno=Anno,hd=H0,tl=T0}=Cons, Ctxt, Sub) -> case Ctxt of effect -> add_warning(Cons, useless_building), - expr(make_effect_seq([H1,T1], Sub), Ctxt, Sub); + make_effect_seq([H1,T1], Sub); value -> ann_c_cons(Anno, H1, T1) end; @@ -248,7 +268,7 @@ expr(#c_tuple{anno=Anno,es=Es0}=Tuple, Ctxt, Sub) -> case Ctxt of effect -> add_warning(Tuple, useless_building), - expr(make_effect_seq(Es, Sub), Ctxt, Sub); + make_effect_seq(Es, Sub); value -> ann_c_tuple(Anno, Es) end; @@ -257,7 +277,7 @@ expr(#c_map{anno=Anno,arg=V0,es=Es0}=Map, Ctxt, Sub) -> case Ctxt of effect -> add_warning(Map, useless_building), - expr(make_effect_seq(Es, Sub), Ctxt, Sub); + make_effect_seq(Es, Sub); value -> V = expr(V0, Ctxt, Sub), ann_c_map(Anno,V,Es) @@ -310,7 +330,7 @@ expr(#c_let{}=Let0, Ctxt, Sub) -> Expr -> %% The let body was successfully moved into the let argument. %% Now recursively re-process the new expression. - expr(Expr, Ctxt, sub_new_preserve_types(Sub)) + Expr end; expr(#c_letrec{body=#c_var{}}=Letrec, effect, _Sub) -> %% This is named fun in an 'effect' context. Warn and ignore. @@ -351,7 +371,7 @@ expr(#c_case{}=Case0, Ctxt, Sub) -> %% (in addition to any warnings that may have been emitted %% according to the rules above). %% - case opt_bool_case(Case0) of + case opt_bool_case(Case0, Sub) of #c_case{arg=Arg0,clauses=Cs0}=Case1 -> Arg1 = body(Arg0, value, Sub), LitExpr = cerl:is_literal(Arg1), @@ -361,10 +381,8 @@ expr(#c_case{}=Case0, Ctxt, Sub) -> warn_no_clause_match(Case1, Case), Expr = eval_case(Case, Sub), case move_case_into_arg(Case, Sub) of - impossible -> - bsm_an(Expr); - Other -> - expr(Other, Ctxt, sub_new_preserve_types(Sub)) + impossible -> Expr; + Other -> Other end; Other -> expr(Other, Ctxt, Sub) @@ -377,10 +395,10 @@ expr(#c_receive{clauses=Cs0,timeout=T0,action=A0}=Recv, Ctxt, Sub) -> expr(#c_apply{anno=Anno,op=Op0,args=As0}=App, _, Sub) -> Op1 = expr(Op0, value, Sub), As1 = expr_list(As0, value, Sub), - case Op1 of - #c_var{} -> + case cerl:is_data(Op1) of + false -> App#c_apply{op=Op1,args=As1}; - _ -> + true -> add_warning(App, invalid_call), Err = #c_call{anno=Anno, module=#c_literal{val=erlang}, @@ -1403,9 +1421,6 @@ sub_new() -> #sub{v=orddict:new(),s=cerl_sets:new(),t=#{}}. sub_new(#sub{}=Sub) -> Sub#sub{v=orddict:new(),t=#{}}. -sub_new_preserve_types(#sub{}=Sub) -> - Sub#sub{v=orddict:new()}. - sub_get_var(#c_var{name=V}=Var, #sub{v=S}) -> case orddict:find(V, S) of {ok,Val} -> Val; @@ -1443,8 +1458,19 @@ sub_add_scope(Vs, #sub{s=Scope0}=Sub) -> Sub#sub{s=Scope}. sub_subst_scope(#sub{v=S0,s=Scope}=Sub) -> - S = [{-1,#c_var{name=Sv}} || Sv <- cerl_sets:to_list(Scope)]++S0, - Sub#sub{v=S}. + Initial = case S0 of + [{NegInt,_}|_] when is_integer(NegInt), NegInt < 0 -> + NegInt - 1; + _ -> + -1 + end, + S = sub_subst_scope_1(cerl_sets:to_list(Scope), Initial, S0), + Sub#sub{v=orddict:from_list(S)}. + +%% The keys in an orddict must be unique. Make them so! +sub_subst_scope_1([H|T], Key, Acc) -> + sub_subst_scope_1(T, Key-1, [{Key,#c_var{name=H}}|Acc]); +sub_subst_scope_1([], _, Acc) -> Acc. sub_is_val(#c_var{name=V}, #sub{v=S,s=Scope}) -> %% When the bottleneck in sub_del_var/2 was eliminated, this @@ -1535,9 +1561,11 @@ will_match(E, [P]) -> will_match_1({false,_}) -> maybe; will_match_1({true,_}) -> yes. -%% opt_bool_case(CoreExpr) - CoreExpr'. -%% Do various optimizations to case statement that has a -%% boolean case expression. +%% opt_bool_case(CoreExpr, Sub) - CoreExpr'. +%% +%% In bodies, do various optimizations to case statements that have +%% boolean case expressions. We don't do the optimizations in guards, +%% because they would thwart the optimization in v3_kernel. %% %% We start with some simple optimizations and normalization %% to facilitate later optimizations. @@ -1546,7 +1574,7 @@ will_match_1({true,_}) -> yes. %% (or fail), we can remove any clause that cannot %% possibly match 'true' or 'false'. Also, any clause %% following both 'true' and 'false' clause can -%% be removed. If successful, we will end up this: +%% be removed. If successful, we will end up like this: %% %% case BoolExpr of case BoolExpr of %% true -> false -> @@ -1557,8 +1585,11 @@ will_match_1({true,_}) -> yes. %% %% We give up if there are clauses with guards, or if there %% is a variable clause that matches anything. -%% -opt_bool_case(#c_case{arg=Arg}=Case0) -> + +opt_bool_case(#c_case{}=Case, #sub{in_guard=true}) -> + %% v3_kernel does a better job without "help". + Case; +opt_bool_case(#c_case{arg=Arg}=Case0, #sub{in_guard=false}) -> case is_bool_expr(Arg) of false -> Case0; @@ -1570,8 +1601,7 @@ opt_bool_case(#c_case{arg=Arg}=Case0) -> impossible -> Case0 end - end; -opt_bool_case(Core) -> Core. + end. opt_bool_clauses(#c_case{clauses=Cs}=Case) -> Case#c_case{clauses=opt_bool_clauses(Cs, false, false)}. @@ -1587,16 +1617,14 @@ opt_bool_clauses(Cs, true, true) -> [] end; opt_bool_clauses([#c_clause{pats=[#c_literal{val=Lit}], - guard=#c_literal{val=true}, - body=B}=C0|Cs], SeenT, SeenF) -> + guard=#c_literal{val=true}}=C|Cs], SeenT, SeenF) -> case is_boolean(Lit) of false -> %% Not a boolean - this clause can't match. - add_warning(C0, nomatch_clause_type), + add_warning(C, nomatch_clause_type), opt_bool_clauses(Cs, SeenT, SeenF); true -> %% This clause will match. - C = C0#c_clause{body=opt_bool_case(B)}, case {Lit,SeenT,SeenF} of {false,_,false} -> [C|opt_bool_clauses(Cs, SeenT, true)]; @@ -1872,10 +1900,10 @@ case_opt_arg_1(E0, Cs0, LitExpr) -> true -> E = case_opt_compiler_generated(E0), Cs = case_opt_nomatch(E, Cs0, LitExpr), - case cerl:data_type(E) of - {atomic,_} -> + case cerl:is_literal(E) of + true -> case_opt_lit(E, Cs); - _ -> + false -> case_opt_data(E, Cs) end end. @@ -2023,10 +2051,10 @@ case_opt_lit_1(_, []) -> []. %% the clauses where it is actually needed. case_opt_data(E, Cs0) -> - Es = cerl:data_es(E), TypeSig = {cerl:data_type(E),cerl:data_arity(E)}, - try case_opt_data_1(Cs0, Es, TypeSig) of + try case_opt_data_1(Cs0, TypeSig) of Cs -> + Es = cerl:data_es(E), {ok,Es,Cs} catch throw:impossible -> @@ -2034,44 +2062,47 @@ case_opt_data(E, Cs0) -> {error,Cs0} end. -case_opt_data_1([{[P0|Ps0],C,PsAcc,Bs0}|Cs], Es, TypeSig) -> +case_opt_data_1([{[P0|Ps0],C,PsAcc,Bs0}|Cs], TypeSig) -> P = case_opt_compiler_generated(P0), - BindTo = #c_var{name=dummy}, - {Ps1,[{BindTo,_}|Bs1]} = case_data_pat_alias(P, BindTo, TypeSig, []), - [{Ps1++Ps0,C,PsAcc,Bs1++Bs0}|case_opt_data_1(Cs, Es, TypeSig)]; -case_opt_data_1([], _, _) -> []. + {Ps1,Bs} = case_opt_data_2(P, TypeSig, Bs0), + [{Ps1++Ps0,C,PsAcc,Bs}|case_opt_data_1(Cs, TypeSig)]; +case_opt_data_1([], _) -> []. -case_data_pat_alias(P, BindTo0, TypeSig, Bs0) -> - case cerl:type(P) of - alias -> - %% Recursively handle the pattern and bind to - %% the alias variable. - BindTo = cerl:alias_var(P), - Apat0 = cerl:alias_pat(P), - Ann = [compiler_generated], - Apat = cerl:set_ann(Apat0, Ann), - {Ps,Bs} = case_data_pat_alias(Apat, BindTo, TypeSig, Bs0), - {Ps,[{BindTo0,BindTo}|Bs]}; - var -> - %% Here we will need to actually build the data and bind - %% it to the variable. +case_opt_data_2(P, TypeSig, Bs0) -> + case case_analyze_pat(P) of + {[],Pat} when Pat =/= none -> + DataEs = cerl:data_es(P), + {DataEs,Bs0}; + {[V|Vs],none} -> {Type,Arity} = TypeSig, Ann = [compiler_generated], Vars = make_vars(Ann, Arity), Data = cerl:ann_make_data(Ann, Type, Vars), - Bs = [{BindTo0,P},{P,Data}|Bs0], + Bs = [{V,Data} | [{Var,V} || Var <- Vs] ++ Bs0], {Vars,Bs}; - _ -> - %% Since case_opt_nomatch/3 has removed all clauses that - %% cannot match, we KNOW that this clause must match and - %% that the pattern must be a data constructor. - %% Here we must build the data and bind it to the variable. + {[V|Vs],Pat} when Pat =/= none -> {Type,_} = TypeSig, - DataEs = cerl:data_es(P), + DataEs = cerl:data_es(Pat), Vars = pat_to_expr_list(DataEs), Ann = [compiler_generated], Data = cerl:ann_make_data(Ann, Type, Vars), - {DataEs,[{BindTo0,Data}]} + Bs = [{V,Data} | [{Var,V} || Var <- Vs] ++ Bs0], + {DataEs,Bs} + end. + +case_analyze_pat(P) -> + case_analyze_pat_1(P, [], none). + +case_analyze_pat_1(P, Vs, Pat) -> + case cerl:type(P) of + alias -> + V = cerl:alias_var(P), + Apat = cerl:alias_pat(P), + case_analyze_pat_1(Apat, [V|Vs], Pat); + var -> + {[P|Vs],Pat}; + _ -> + {Vs,P} end. %% pat_to_expr(Pattern) -> Expression. @@ -2115,7 +2146,7 @@ make_var(A) -> make_var_name() -> N = get(new_var_num), put(new_var_num, N+1), - list_to_atom("fol"++integer_to_list(N)). + list_to_atom("@f"++integer_to_list(N)). letify(Bs, Body) -> Ann = cerl:get_ann(Body), @@ -2129,7 +2160,7 @@ letify(Bs, Body) -> -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 + case opt_not_in_let_0(Vs0, Arg0, Body0) of {[],#c_values{es=[]},Body} -> Body; {Vs,Arg,Body} -> @@ -2137,13 +2168,7 @@ opt_not_in_let(#c_let{vars=[_]=Vs0,arg=Arg0,body=Body0}=Let) -> 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) -> +opt_not_in_let_0([#c_var{name=V}]=Vs0, Arg0, Body0) -> case cerl:type(Body0) of call -> %% let <V> = Expr in not V ==> @@ -2174,9 +2199,7 @@ opt_not_in_let([#c_var{name=V}]=Vs0, Arg0, Body0) -> end; _ -> {Vs0,Arg0,Body0} - end; -opt_not_in_let(Vs, Arg, Body) -> - {Vs,Arg,Body}. + end. opt_not_in_let_1(V, Call, Body) -> case Call of @@ -2222,24 +2245,24 @@ inverse_rel_op('=<') -> '>'; inverse_rel_op(_) -> no. -%% opt_bool_case_in_let(LetExpr, Sub) -> Core +%% opt_bool_case_in_let(LetExpr) -> Core 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_bool_case_in_let_1(Vs, Arg, B, Let, Sub). -opt_case_in_let_1([#c_var{name=V}], Arg, +opt_bool_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 = opt_bool_case(Case0#c_case{arg=Arg}, Sub), case core_lib:is_var_used(V, Case) of - false -> expr(Case, sub_new(Sub)); + false -> Case; true -> Let end; false -> Let end; -opt_case_in_let_1(_, _, _, Let, _) -> Let. +opt_bool_case_in_let_1(_, _, _, Let, _) -> Let. %% is_simple_case_arg(Expr) -> true|false %% Determine whether the Expr is simple enough to be worth @@ -2372,9 +2395,7 @@ is_safe_bool_expr_list([], _, _) -> true. %% as a let or a sequence, move the original let body into the complex %% expression. -simplify_let(#c_let{arg=Arg0}=Let0, Sub) -> - Arg = opt_bool_case(Arg0), - Let = Let0#c_let{arg=Arg}, +simplify_let(#c_let{arg=Arg}=Let, Sub) -> move_let_into_expr(Let, Arg, Sub). move_let_into_expr(#c_let{vars=InnerVs0,body=InnerBody0}=Inner, @@ -2630,11 +2651,10 @@ opt_simple_let_0(#c_let{arg=Arg0}=Let, Ctxt, Sub) -> opt_simple_let_1(#c_let{vars=Vs0,body=B0}=Let, Arg0, Ctxt, Sub0) -> %% Optimise let and add new substitutions. - {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), + {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), opt_simple_let_2(Let, Vs, Arg, B, B0, Ctxt, Sub1). opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> @@ -2647,25 +2667,23 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> false -> %% let <Var> = Arg in <OtherVar> ==> seq Arg OtherVar Arg = maybe_suppress_warnings(Arg1, Vs0, PrevBody), - expr(#c_seq{arg=Arg,body=Body}, Ctxt, - sub_new_preserve_types(Sub)) + #c_seq{arg=Arg,body=Body} end; {[],#c_values{es=[]},_} -> %% No variables left. Body; {Vs,Arg1,#c_literal{}} -> Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody), - E = case Ctxt of - effect -> - %% Throw away the literal body. - Arg; - value -> - %% Since the variable is not used in the body, we - %% can rewrite the let to a sequence. - %% let <Var> = Arg in Literal ==> seq Arg Literal - #c_seq{arg=Arg,body=Body} - end, - expr(E, Ctxt, sub_new_preserve_types(Sub)); + case Ctxt of + effect -> + %% Throw away the literal body. + Arg; + value -> + %% Since the variable is not used in the body, we + %% can rewrite the let to a sequence. + %% let <Var> = Arg in Literal ==> seq Arg Literal + #c_seq{arg=Arg,body=Body} + end; {Vs,Arg1,Body} -> %% If none of the variables are used in the body, we can %% rewrite the let to a sequence: @@ -2674,12 +2692,10 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> case is_any_var_used(Vs, Body) of false -> Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody), - expr(#c_seq{arg=Arg,body=Body}, Ctxt, - sub_new_preserve_types(Sub)); + #c_seq{arg=Arg,body=Body}; true -> Let1 = Let0#c_let{vars=Vs,arg=Arg1,body=Body}, - Let2 = opt_bool_case_in_let(Let1, Sub), - opt_case_in_let_arg(Let2, Ctxt, Sub) + opt_bool_case_in_let(Let1, Sub) end end. @@ -2807,48 +2823,6 @@ move_case_into_arg(#c_case{arg=#c_seq{arg=OuterArg,body=InnerArg}=Outer, move_case_into_arg(_, _) -> impossible. -%% In guards only, rewrite a case in a let argument like -%% -%% let <Var> = case <> of -%% <> when AnyGuard -> Literal1; -%% <> when AnyGuard -> Literal2 -%% end -%% in LetBody -%% -%% to -%% -%% case <> of -%% <> when AnyGuard -> -%% let <Var> = Literal1 in LetBody -%% <> 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 -%% size. (Doing this transformation outside of guards could -%% lead to a substantational increase in code size.) -%% -opt_case_in_let_arg(#c_let{arg=#c_case{}=Case}=Let, Ctxt, - #sub{in_guard=true}=Sub) -> - opt_case_in_let_arg_1(Let, Case, Ctxt, Sub); -opt_case_in_let_arg(Let, _, _) -> Let. - -opt_case_in_let_arg_1(Let0, #c_case{arg=#c_values{es=[]}, - clauses=Cs}=Case0, Ctxt, Sub) -> - Let = mark_compiler_generated(Let0), - case Cs of - [#c_clause{body=#c_literal{}=BodyA}=Ca0, - #c_clause{body=#c_literal{}=BodyB}=Cb0] -> - Ca = Ca0#c_clause{body=Let#c_let{arg=BodyA}}, - Cb = Cb0#c_clause{body=Let#c_let{arg=BodyB}}, - Case = Case0#c_case{clauses=[Ca,Cb]}, - expr(Case, Ctxt, sub_new_preserve_types(Sub)); - _ -> Let - end; -opt_case_in_let_arg_1(Let, _, _, _) -> Let. - is_any_var_used([#c_var{name=V}|Vs], Expr) -> case core_lib:is_var_used(V, Expr) of false -> is_any_var_used(Vs, Expr); @@ -2956,7 +2930,9 @@ returns_integer(bit_size, [_]) -> true; returns_integer('bsl', [_,_]) -> true; returns_integer('bsr', [_,_]) -> true; returns_integer(byte_size, [_]) -> true; +returns_integer(ceil, [_]) -> true; returns_integer('div', [_,_]) -> true; +returns_integer(floor, [_]) -> true; returns_integer(length, [_]) -> true; returns_integer('rem', [_,_]) -> true; returns_integer('round', [_]) -> true; @@ -2974,15 +2950,8 @@ update_types(Expr, Pat, #sub{t=Tdb0}=Sub) -> Tdb = update_types_1(Expr, Pat, Tdb0), Sub#sub{t=Tdb}. -update_types_1(#c_var{name=V,anno=Anno}, Pat, Types) -> - case member(reuse_for_context, Anno) of - true -> - %% If a variable has been marked for reuse of binary context, - %% optimizations based on type information are unsafe. - kill_types(V, Types); - false -> - update_types_2(V, Pat, Types) - end; +update_types_1(#c_var{name=V}, Pat, Types) -> + update_types_2(V, Pat, Types); update_types_1(_, _, Types) -> Types. update_types_2(V, [#c_tuple{}=P], Types) -> @@ -3025,274 +2994,14 @@ copy_type(_, _, Tdb) -> Tdb. void() -> #c_literal{val=ok}. -%%% -%%% Annotate bit syntax matching to faciliate optimization in further passes. -%%% - -bsm_an(#c_case{arg=#c_var{}=V}=Case) -> - bsm_an_1([V], Case); -bsm_an(#c_case{arg=#c_values{es=Es}}=Case) -> - bsm_an_1(Es, Case); -bsm_an(Other) -> Other. - -bsm_an_1(Vs, #c_case{clauses=Cs}=Case) -> - case bsm_leftmost(Cs) of - none -> Case; - Pos -> bsm_an_2(Vs, Cs, Case, Pos) - end. - -bsm_an_2(Vs, Cs, Case, Pos) -> - case bsm_nonempty(Cs, Pos) of - true -> bsm_an_3(Vs, Cs, Case, Pos); - false -> Case - end. - -bsm_an_3(Vs, Cs, Case, Pos) -> - try - bsm_ensure_no_partition(Cs, Pos), - bsm_do_an(Vs, Pos, Cs, Case) - catch - throw:{problem,Where,What} -> - add_bin_opt_info(Where, What), - Case - end. - -bsm_do_an(Vs0, Pos, Cs0, Case) -> - case nth(Pos, Vs0) of - #c_var{name=Vname}=V0 -> - Cs = bsm_do_an_var(Vname, Pos, Cs0, []), - V = bsm_annotate_for_reuse(V0), - Bef = lists:sublist(Vs0, Pos-1), - Aft = lists:nthtail(Pos, Vs0), - case Bef ++ [V|Aft] of - [_] -> - Case#c_case{arg=V,clauses=Cs}; - Vs -> - Case#c_case{arg=#c_values{es=Vs},clauses=Cs} - end; - _ -> - Case - end. - -bsm_do_an_var(V, S, [#c_clause{pats=Ps,guard=G,body=B0}=C0|Cs], Acc) -> - case nth(S, Ps) of - #c_var{name=VarName} -> - case core_lib:is_var_used(V, G) of - true -> bsm_problem(C0, orig_bin_var_used_in_guard); - false -> ok - end, - case core_lib:is_var_used(VarName, G) of - true -> bsm_problem(C0, bin_var_used_in_guard); - false -> ok - end, - B1 = bsm_maybe_ctx_to_binary(VarName, B0), - B = bsm_maybe_ctx_to_binary(V, B1), - C = C0#c_clause{body=B}, - bsm_do_an_var(V, S, Cs, [C|Acc]); - #c_alias{}=P -> - case bsm_could_match_binary(P) of - false -> - bsm_do_an_var(V, S, Cs, [C0|Acc]); - true -> - bsm_problem(C0, bin_opt_alias) - end; - P -> - case bsm_could_match_binary(P) andalso bsm_is_var_used(V, G, B0) of - false -> - bsm_do_an_var(V, S, Cs, [C0|Acc]); - true -> - bsm_problem(C0, bin_var_used) - end - end; -bsm_do_an_var(_, _, [], Acc) -> reverse(Acc). - -bsm_annotate_for_reuse(#c_var{anno=Anno}=Var) -> - case member(reuse_for_context, Anno) of - false -> Var#c_var{anno=[reuse_for_context|Anno]}; - true -> Var - end. - -bsm_is_var_used(V, G, B) -> - core_lib:is_var_used(V, G) orelse core_lib:is_var_used(V, B). - -bsm_maybe_ctx_to_binary(V, B) -> - case core_lib:is_var_used(V, B) andalso not previous_ctx_to_binary(V, B) of - false -> - B; - true -> - #c_seq{arg=#c_primop{name=#c_literal{val=bs_context_to_binary}, - args=[#c_var{name=V}]}, - body=B} - end. - -previous_ctx_to_binary(V, Core) -> - case Core of - #c_seq{arg=#c_primop{name=#c_literal{val=bs_context_to_binary}, - args=[#c_var{name=V}]}} -> - true; - _ -> - false - end. - -%% bsm_leftmost(Cs) -> none | ArgumentNumber -%% Find the leftmost argument that does binary matching. Return -%% the number of the argument (1-N). - -bsm_leftmost(Cs) -> - bsm_leftmost_1(Cs, none). - -bsm_leftmost_1([#c_clause{pats=Ps}|Cs], Pos) -> - bsm_leftmost_2(Ps, Cs, 1, Pos); -bsm_leftmost_1([], Pos) -> Pos. - -bsm_leftmost_2(_, Cs, Pos, Pos) -> - bsm_leftmost_1(Cs, Pos); -bsm_leftmost_2([#c_binary{}|_], Cs, N, _) -> - bsm_leftmost_1(Cs, N); -bsm_leftmost_2([_|Ps], Cs, N, Pos) -> - bsm_leftmost_2(Ps, Cs, N+1, Pos); -bsm_leftmost_2([], Cs, _, Pos) -> - bsm_leftmost_1(Cs, Pos). - -%% bsm_nonempty(Cs, Pos) -> true|false -%% Check if at least one of the clauses matches a non-empty -%% binary in the given argument position. -%% -bsm_nonempty([#c_clause{pats=Ps}|Cs], Pos) -> - case nth(Pos, Ps) of - #c_binary{segments=[_|_]} -> - true; - _ -> - bsm_nonempty(Cs, Pos) - end; -bsm_nonempty([], _ ) -> false. - -%% bsm_ensure_no_partition(Cs, Pos) -> ok (exception if problem) -%% We must make sure that matching is not partitioned between -%% variables like this: -%% foo(<<...>>) -> ... -%% foo(<Variable>) when ... -> ... -%% foo(<Any non-variable pattern>) -> -%% If there is such partition, we are not allowed to reuse the binary variable -%% for the match context. -%% -%% Also, arguments to the left of the argument that is matched -%% against a binary, are only allowed to be simple variables, not -%% used in guards. The reason is that we must know that the binary is -%% only matched in one place (i.e. there must be only one bs_start_match2 -%% instruction emitted). - -bsm_ensure_no_partition(Cs, Pos) -> - bsm_ensure_no_partition_1(Cs, Pos, before). - -%% Loop through each clause. -bsm_ensure_no_partition_1([#c_clause{pats=Ps,guard=G}|Cs], Pos, State0) -> - State = bsm_ensure_no_partition_2(Ps, Pos, G, simple_vars, State0), - case State of - 'after' -> - bsm_ensure_no_partition_after(Cs, Pos); - _ -> - ok - end, - bsm_ensure_no_partition_1(Cs, Pos, State); -bsm_ensure_no_partition_1([], _, _) -> ok. - -%% Loop through each pattern for this clause. -bsm_ensure_no_partition_2([#c_binary{}=Where|_], 1, _, Vstate, State) -> - case State of - before when Vstate =:= simple_vars -> within; - before -> bsm_problem(Where, Vstate); - within when Vstate =:= simple_vars -> within; - within -> bsm_problem(Where, Vstate) - end; -bsm_ensure_no_partition_2([#c_alias{}=Alias|_], 1, N, Vstate, State) -> - %% Retrieve the real pattern that the alias refers to and check that. - P = bsm_real_pattern(Alias), - bsm_ensure_no_partition_2([P], 1, N, Vstate, State); -bsm_ensure_no_partition_2([_|_], 1, _, _Vstate, before=State) -> - %% No binary matching yet - therefore no partition. - State; -bsm_ensure_no_partition_2([P|_], 1, _, Vstate, State) -> - case bsm_could_match_binary(P) of - false -> - %% If clauses can be freely arranged (Vstate =:= simple_vars), - %% a clause that cannot match a binary will not partition the clause. - %% Example: - %% - %% a(Var, <<>>) -> ... - %% a(Var, []) -> ... - %% a(Var, <<B>>) -> ... - %% - %% But if the clauses can't be freely rearranged, as in - %% - %% b(Var, <<X>>) -> ... - %% b(1, 2) -> ... - %% - %% we do have a problem. - %% - case Vstate of - simple_vars -> State; - _ -> bsm_problem(P, Vstate) - end; - true -> - %% The pattern P *may* match a binary, so we must update the state. - %% (P must be a variable.) - case State of - within -> 'after'; - 'after' -> 'after' - end - end; -bsm_ensure_no_partition_2([#c_var{name=V}|Ps], N, G, Vstate, S) -> - case core_lib:is_var_used(V, G) of - false -> - bsm_ensure_no_partition_2(Ps, N-1, G, Vstate, S); - true -> - bsm_ensure_no_partition_2(Ps, N-1, G, bin_left_var_used_in_guard, S) - end; -bsm_ensure_no_partition_2([_|Ps], N, G, _, S) -> - bsm_ensure_no_partition_2(Ps, N-1, G, bin_argument_order, S). - -bsm_ensure_no_partition_after([#c_clause{pats=Ps}=C|Cs], Pos) -> - case nth(Pos, Ps) of - #c_var{} -> - bsm_ensure_no_partition_after(Cs, Pos); - _ -> - bsm_problem(C, 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; -bsm_could_match_binary(#c_literal{val=Lit}) -> is_bitstring(Lit); -bsm_could_match_binary(_) -> true. - -bsm_real_pattern(#c_alias{pat=P}) -> bsm_real_pattern(P); -bsm_real_pattern(P) -> P. - -bsm_problem(Where, What) -> - throw({problem,Where,What}). %%% %%% Handling of warnings. %%% -mark_compiler_generated(Term) -> - cerl_trees:map(fun mark_compiler_generated_1/1, Term). - -mark_compiler_generated_1(#c_call{anno=Anno}=Term) -> - Term#c_call{anno=[compiler_generated|Anno--[compiler_generated]]}; -mark_compiler_generated_1(Term) -> Term. - init_warnings() -> put({?MODULE,warnings}, []). -add_bin_opt_info(Core, Term) -> - case get(bin_opt_info) of - true -> add_warning(Core, Term); - false -> ok - end. - add_warning(Core, Term) -> case should_suppress_warning(Core) of true -> @@ -3414,28 +3123,7 @@ format_error(result_ignored) -> format_error(invalid_call) -> "invalid function call"; format_error(useless_building) -> - "a term is constructed, but never used"; -format_error(bin_opt_alias) -> - "INFO: the '=' operator will prevent delayed sub binary optimization"; -format_error(bin_partition) -> - "INFO: matching non-variables after a previous clause matching a variable " - "will prevent delayed sub binary optimization"; -format_error(bin_left_var_used_in_guard) -> - "INFO: a variable to the left of the binary pattern is used in a guard; " - "will prevent delayed sub binary optimization"; -format_error(bin_argument_order) -> - "INFO: matching anything else but a plain variable to the left of " - "binary pattern will prevent delayed sub binary optimization; " - "SUGGEST changing argument order"; -format_error(bin_var_used) -> - "INFO: using a matched out sub binary will prevent " - "delayed sub binary optimization"; -format_error(orig_bin_var_used_in_guard) -> - "INFO: using the original binary variable in a guard will prevent " - "delayed sub binary optimization"; -format_error(bin_var_used_in_guard) -> - "INFO: using a matched out sub binary in a guard will prevent " - "delayed sub binary optimization". + "a term is constructed, but never used". -ifdef(DEBUG). %% In order for simplify_let/2 to work correctly, the list of @@ -3446,12 +3134,18 @@ format_error(bin_var_used_in_guard) -> verify_scope(E, #sub{s=Scope}) -> Free0 = cerl_trees:free_variables(E), Free = [V || V <- Free0, not is_tuple(V)], %Ignore function names. - case ordsets:is_subset(Free, cerl_sets:to_list(Scope)) of - true -> true; + case is_subset_of_scope(Free, Scope) of + true -> + true; false -> io:format("~p\n", [E]), io:format("~p\n", [Free]), - io:format("~p\n", [cerl_sets:to_list(Scope)]), + io:format("~p\n", [ordsets:from_list(cerl_sets:to_list(Scope))]), false end. + +is_subset_of_scope([V|Vs], Scope) -> + cerl_sets:is_element(V, Scope) andalso is_subset_of_scope(Vs, Scope); +is_subset_of_scope([], _) -> true. + -endif. |