diff options
Diffstat (limited to 'lib/compiler/src/sys_core_fold.erl')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 51 |
1 files changed, 46 insertions, 5 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 1cdbac5693..e302e2324d 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -305,6 +305,10 @@ expr(#c_let{}=Let, Ctxt, Sub) -> %% Now recursively re-process the new expression. expr(Expr, Ctxt, sub_new_preserve_types(Sub)) end; +expr(#c_letrec{body=#c_var{}}=Letrec, effect, _Sub) -> + %% This is named fun in an 'effect' context. Warn and ignore. + add_warning(Letrec, useless_building), + void(); expr(#c_letrec{defs=Fs0,body=B0}=Letrec, Ctxt, Sub) -> Fs1 = map(fun ({Name,Fb}) -> {Name,expr(Fb, {letrec,Ctxt}, Sub)} @@ -598,6 +602,14 @@ eval_binary_1([#c_bitstr{val=#c_literal{val=Val},size=#c_literal{val=Sz}, error:_ -> throw(impossible) end; +eval_binary_1([#c_bitstr{val=#c_literal{},size=#c_literal{}, + unit=#c_literal{},type=#c_literal{}, + flags=#c_cons{}=Flags}=Bitstr|Ss], Acc0) -> + case cerl:fold_literal(Flags) of + #c_literal{} = Flags1 -> + eval_binary_1([Bitstr#c_bitstr{flags=Flags1}|Ss], Acc0); + _ -> throw(impossible) + end; eval_binary_1([], Acc) -> Acc; eval_binary_1(_, _) -> throw(impossible). @@ -1536,9 +1548,17 @@ map_pair_pattern_list(Ps0, Isub, Osub0) -> {Ps,{_,Osub}} = mapfoldl(fun map_pair_pattern/2, {Isub,Osub0}, Ps0), {Ps,Osub}. -map_pair_pattern(#c_map_pair{op=#c_literal{val=exact},key=K0,val=V0}=Pair, {Isub,Osub0}) -> - {K,Osub1} = pattern(K0, Isub, Osub0), - {V,Osub} = pattern(V0, Isub, Osub1), +map_pair_pattern(#c_map_pair{op=#c_literal{val=exact},key=K0,val=V0}=Pair,{Isub,Osub0}) -> + {K,Osub1} = case cerl:type(K0) of + binary -> + K1 = eval_binary(K0), + case cerl:type(K1) of + literal -> {K1,Osub0}; + _ -> pattern(K0,Isub,Osub0) + end; + _ -> pattern(K0,Isub,Osub0) + end, + {V,Osub} = pattern(V0,Isub,Osub1), {Pair#c_map_pair{key=K,val=V},{Isub,Osub}}. bin_pattern_list(Ps0, Isub, Osub0) -> @@ -1925,9 +1945,30 @@ eval_case(#c_case{arg=E,clauses=[#c_clause{pats=Ps0,body=B}]}, Sub) -> true -> cerl:values_es(E); false -> [E] end, - {true,Bs} = cerl_clauses:match_list(Ps0, Es), + %% Consider: + %% + %% case SomeSideEffect() of + %% X=Y -> ... + %% end + %% + %% We must not rewrite it to: + %% + %% let <X,Y> = <SomeSideEffect(),SomeSideEffect()> in ... + %% + %% because SomeSideEffect() would be called evaluated twice. + %% + %% Instead we must evaluate the case expression in an outer let + %% like this: + %% + %% let NewVar = SomeSideEffect() in + %% let <X,Y> = <NewVar,NewVar> in ... + %% + Vs = make_vars([], length(Es)), + {true,Bs} = cerl_clauses:match_list(Ps0, Vs), {Ps,As} = unzip(Bs), - expr(#c_let{vars=Ps,arg=core_lib:make_values(As),body=B}, sub_new(Sub)); + InnerLet = cerl:c_let(Ps, core_lib:make_values(As), B), + Let = cerl:c_let(Vs, E, InnerLet), + expr(Let, sub_new(Sub)); eval_case(Case, _) -> Case. %% case_opt(CaseArg, [Clause]) -> {CaseArg,[Clause]}. |