diff options
Diffstat (limited to 'lib/compiler/src/sys_core_fold.erl')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 72 |
1 files changed, 50 insertions, 22 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 068478496b..96015fbe58 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1,19 +1,19 @@ %% %% %CopyrightBegin% -%% -%% Copyright Ericsson AB 1999-2009. All Rights Reserved. -%% +%% +%% Copyright Ericsson AB 1999-2010. All Rights Reserved. +%% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in %% compliance with the License. You should have received a copy of the %% Erlang Public License along with this software. If not, it can be %% retrieved online at http://www.erlang.org/. -%% +%% %% Software distributed under the License is distributed on an "AS IS" %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See %% the License for the specific language governing rights and limitations %% under the License. -%% +%% %% %CopyrightEnd% %% %% Purpose : Constant folding optimisation for Core @@ -602,15 +602,23 @@ count_bits_1(Int, Bits) -> count_bits_1(Int bsr 64, Bits+64). %% a rewritten expression consisting of a sequence of %% the arguments only is returned. -useless_call(effect, #c_call{module=#c_literal{val=Mod}, +useless_call(effect, #c_call{anno=Anno, + module=#c_literal{val=Mod}, name=#c_literal{val=Name}, args=Args}=Call) -> A = length(Args), case erl_bifs:is_safe(Mod, Name, A) of false -> case erl_bifs:is_pure(Mod, Name, A) of - true -> add_warning(Call, result_ignored); - false -> ok + true -> + case member(result_not_wanted, Anno) of + false -> + add_warning(Call, result_ignored); + true -> + ok + end; + false -> + ok end, no; true -> @@ -1030,6 +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 @@ -1186,19 +1196,22 @@ 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 -> @@ -1207,6 +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. @@ -2806,7 +2833,8 @@ format_error({no_effect,{erlang,F,A}}) -> end, flatten(io_lib:format(Fmt, Args)); format_error(result_ignored) -> - "the result of the expression is ignored"; + "the result of the expression is ignored " + "(suppress the warning by assigning the expression to the _ variable)"; format_error(useless_building) -> "a term is constructed, but never used"; format_error(bin_opt_alias) -> |