diff options
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 77 |
1 files changed, 41 insertions, 36 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index b8df4e04f8..303ce52ee3 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -121,7 +121,10 @@ module(#c_module{defs=Ds0}=Mod, Opts) -> 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 -> @@ -130,6 +133,14 @@ 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. @@ -240,7 +251,7 @@ 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; @@ -249,7 +260,7 @@ 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; @@ -258,7 +269,7 @@ 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) @@ -311,7 +322,7 @@ 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. @@ -365,7 +376,7 @@ expr(#c_case{}=Case0, Ctxt, Sub) -> impossible -> bsm_an(Expr); Other -> - expr(Other, Ctxt, sub_new_preserve_types(Sub)) + Other end; Other -> expr(Other, Ctxt, Sub) @@ -1398,9 +1409,6 @@ 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; @@ -2220,24 +2228,24 @@ 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(#c_let{vars=Vs,arg=Arg,body=B}=Let) -> + opt_bool_case_in_let_1(Vs, Arg, B, Let). -opt_case_in_let_1([#c_var{name=V}], Arg, - #c_case{arg=#c_var{name=V}}=Case0, Let, Sub) -> +opt_bool_case_in_let_1([#c_var{name=V}], Arg, + #c_case{arg=#c_var{name=V}}=Case0, Let) -> 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)); + 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 @@ -2645,25 +2653,23 @@ 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: @@ -2672,11 +2678,10 @@ 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), + Let2 = opt_bool_case_in_let(Let1), opt_case_in_let_arg(Let2, Ctxt, Sub) end end. @@ -2834,16 +2839,16 @@ opt_case_in_let_arg(#c_let{arg=#c_case{}=Case}=Let, Ctxt, 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) -> + 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 + Case0#c_case{clauses=[Ca,Cb]}; + _ -> + Let end; opt_case_in_let_arg_1(Let, _, _, _) -> Let. |