diff options
Diffstat (limited to 'lib/compiler/src/beam_jump.erl')
| -rw-r--r-- | lib/compiler/src/beam_jump.erl | 64 |
1 files changed, 20 insertions, 44 deletions
diff --git a/lib/compiler/src/beam_jump.erl b/lib/compiler/src/beam_jump.erl index 48b5a32814..4365451356 100644 --- a/lib/compiler/src/beam_jump.erl +++ b/lib/compiler/src/beam_jump.erl @@ -23,7 +23,7 @@ -export([module/2, is_unreachable_after/1,is_exit_instruction/1, - remove_unused_labels/1,is_label_used_in/2]). + remove_unused_labels/1]). %%% The following optimisations are done: %%% @@ -130,6 +130,11 @@ -import(lists, [reverse/1,reverse/2,foldl/3]). +-type instruction() :: beam_utils:instruction(). + +-spec module(beam_utils:module_code(), [compile:option()]) -> + {'ok',beam_utils:module_code()}. + module({Mod,Exp,Attr,Fs0,Lc}, _Opt) -> Fs = [function(F) || F <- Fs0], {ok,{Mod,Exp,Attr,Fs,Lc}}. @@ -155,9 +160,7 @@ share(Is0) -> Is = eliminate_fallthroughs(Is0, []), share_1(Is, #{}, [], []). -share_1([{label,_}=Lbl|Is], Dict, [], Acc) -> - share_1(Is, Dict, [], [Lbl|Acc]); -share_1([{label,L}=Lbl|Is], Dict0, Seq, Acc) -> +share_1([{label,L}=Lbl|Is], Dict0, [_|_]=Seq, Acc) -> case maps:find(Seq, Dict0) of error -> Dict = maps:put(Seq, L, Dict0), @@ -208,21 +211,18 @@ sharable_with_try([]) -> true. %% Eliminate all fallthroughs. Return the result reversed. -eliminate_fallthroughs([I,{label,L}=Lbl|Is], Acc) -> - case is_unreachable_after(I) orelse is_label(I) of +eliminate_fallthroughs([{label,L}=Lbl|Is], [I|_]=Acc) -> + case is_unreachable_after(I) of false -> %% Eliminate fallthrough. - eliminate_fallthroughs(Is, [Lbl,{jump,{f,L}},I|Acc]); + eliminate_fallthroughs(Is, [Lbl,{jump,{f,L}}|Acc]); true -> - eliminate_fallthroughs(Is, [Lbl,I|Acc]) + eliminate_fallthroughs(Is, [Lbl|Acc]) end; eliminate_fallthroughs([I|Is], Acc) -> eliminate_fallthroughs(Is, [I|Acc]); eliminate_fallthroughs([], Acc) -> Acc. -is_label({label,_}) -> true; -is_label(_) -> false. - %%% %%% (2) Move short code sequences ending in an instruction that causes an exit %%% to the end of the function. @@ -274,9 +274,9 @@ extract_seq_1(_, _) -> no. -record(st, { - entry, %Entry label (must not be moved). - mlbl, %Moved labels. - labels :: cerl_sets:set() %Set of referenced labels. + entry :: beam_asm:label(), %Entry label (must not be moved). + mlbl :: #{beam_asm:label() := [beam_asm:label()]}, %Moved labels. + labels :: cerl_sets:set() %Set of referenced labels. }). opt(Is0, CLabel) -> @@ -458,6 +458,8 @@ is_label_used(L, St) -> %% is_unreachable_after(Instruction) -> boolean() %% Test whether the code after Instruction is unreachable. +-spec is_unreachable_after(instruction()) -> boolean(). + is_unreachable_after({func_info,_M,_F,_A}) -> true; is_unreachable_after(return) -> true; is_unreachable_after({jump,_Lbl}) -> true; @@ -470,6 +472,8 @@ is_unreachable_after(I) -> is_exit_instruction(I). %% Test whether the instruction Instruction always %% causes an exit/failure. +-spec is_exit_instruction(instruction()) -> boolean(). + is_exit_instruction({call_ext,_,{extfunc,M,F,A}}) -> erl_bifs:is_exit_bif(M, F, A); is_exit_instruction(if_end) -> true; @@ -478,40 +482,12 @@ is_exit_instruction({try_case_end,_}) -> true; is_exit_instruction({badmatch,_}) -> true; is_exit_instruction(_) -> false. -%% is_label_used_in(LabelNumber, [Instruction]) -> boolean() -%% Check whether the label is used in the instruction sequence -%% (including inside blocks). - -is_label_used_in(Lbl, Is) -> - is_label_used_in_1(Is, Lbl, cerl_sets:new()). - -is_label_used_in_1([{block,Block}|Is], Lbl, Empty) -> - lists:any(fun(I) -> is_label_used_in_block(I, Lbl) end, Block) - orelse is_label_used_in_1(Is, Lbl, Empty); -is_label_used_in_1([I|Is], Lbl, Empty) -> - Used = ulbl(I, Empty), - cerl_sets:is_element(Lbl, Used) orelse is_label_used_in_1(Is, Lbl, Empty); -is_label_used_in_1([], _, _) -> false. - -is_label_used_in_block({set,_,_,Info}, Lbl) -> - case Info of - {bif,_,{f,F}} -> F =:= Lbl; - {alloc,_,{gc_bif,_,{f,F}}} -> F =:= Lbl; - {alloc,_,{put_map,_,{f,F}}} -> F =:= Lbl; - {get_map_elements,{f,F}} -> F =:= Lbl; - {try_catch,_,{f,F}} -> F =:= Lbl; - {alloc,_,_} -> false; - {put_tuple,_} -> false; - {get_tuple_element,_} -> false; - {set_tuple_element,_} -> false; - {line,_} -> false; - _ when is_atom(Info) -> false - end. - %% remove_unused_labels(Instructions0) -> Instructions %% Remove all unused labels. Also remove unreachable %% instructions following labels that are removed. +-spec remove_unused_labels([instruction()]) -> [instruction()]. + remove_unused_labels(Is) -> Used0 = initial_labels(Is), Used = foldl(fun ulbl/2, Used0, Is), |