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authorBjörn Gustavsson <[email protected]>2018-06-07 13:29:47 +0200
committerGitHub <[email protected]>2018-06-07 13:29:47 +0200
commit890936f03991e7b57d7801497a2de5a572b701de (patch)
tree1fab410b660842dcdcde6af7adde2fca21626677 /lib
parent463c8e7fa08388f138fd9f07995d7c7a7580507e (diff)
parent84d0923cc193e0fb06c21ecdfd08d5b204015628 (diff)
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Merge pull request #1832 from josevalim/jv-revert-beam-jump
Revert "Run the sharing optimisation in beam_jump until fixpoint"
Diffstat (limited to 'lib')
-rw-r--r--lib/compiler/src/beam_jump.erl65
1 files changed, 25 insertions, 40 deletions
diff --git a/lib/compiler/src/beam_jump.erl b/lib/compiler/src/beam_jump.erl
index c33de217bd..576d20505d 100644
--- a/lib/compiler/src/beam_jump.erl
+++ b/lib/compiler/src/beam_jump.erl
@@ -156,46 +156,41 @@ function({function,Name,Arity,CLabel,Asm0}) ->
%%%
share(Is0) ->
- Is1 = eliminate_fallthroughs(Is0, []),
- Is2 = find_fixpoint(fun(Is) ->
- share_1(Is, #{}, #{}, [], [])
- end, Is1),
- reverse(Is2).
+ %% We will get more sharing if we never fall through to a label.
+ Is = eliminate_fallthroughs(Is0, []),
+ share_1(Is, #{}, [], []).
-share_1([{label,L}=Lbl|Is], Dict0, Lbls0, [_|_]=Seq, Acc) ->
+share_1([{label,L}=Lbl|Is], Dict0, [_|_]=Seq, Acc) ->
case maps:find(Seq, Dict0) of
error ->
Dict = maps:put(Seq, L, Dict0),
- share_1(Is, Dict, Lbls0, [], [Lbl|Seq ++ Acc]);
+ share_1(Is, Dict, [], [Lbl|Seq ++ Acc]);
{ok,Label} ->
- Lbls = maps:put(L, Label, Lbls0),
- share_1(Is, Dict0, Lbls, [], [Lbl,{jump,{f,Label}}|Acc])
+ share_1(Is, Dict0, [], [Lbl,{jump,{f,Label}}|Acc])
end;
-share_1([{func_info,_,_,_}|_]=Is, _, Lbls, [], Acc) when Lbls =/= #{} ->
- beam_utils:replace_labels(Acc, Is, Lbls, fun(Old) -> Old end);
-share_1([{func_info,_,_,_}|_]=Is, _, Lbls, [], Acc) when Lbls =:= #{} ->
- reverse(Acc, Is);
-share_1([{'catch',_,_}=I|Is], Dict0, Lbls0, Seq, Acc) ->
- {Dict,Lbls} = clean_non_sharable(Dict0, Lbls0),
- share_1(Is, Dict, Lbls, [I|Seq], Acc);
-share_1([{'try',_,_}=I|Is], Dict0, Lbls0, Seq, Acc) ->
- {Dict,Lbls} = clean_non_sharable(Dict0, Lbls0),
- share_1(Is, Dict, Lbls, [I|Seq], Acc);
-share_1([{try_case,_}=I|Is], Dict0, Lbls0, Seq, Acc) ->
- {Dict,Lbls} = clean_non_sharable(Dict0, Lbls0),
- share_1(Is, Dict, Lbls, [I|Seq], Acc);
-share_1([{catch_end,_}=I|Is], Dict0, Lbls0, Seq, Acc) ->
- {Dict,Lbls} = clean_non_sharable(Dict0, Lbls0),
- share_1(Is, Dict, Lbls, [I|Seq], Acc);
-share_1([I|Is], Dict, Lbls, Seq, Acc) ->
+share_1([{func_info,_,_,_}=I|Is], _, [], Acc) ->
+ reverse(Is, [I|Acc]);
+share_1([{'catch',_,_}=I|Is], Dict0, Seq, Acc) ->
+ Dict = clean_non_sharable(Dict0),
+ share_1(Is, Dict, [I|Seq], Acc);
+share_1([{'try',_,_}=I|Is], Dict0, Seq, Acc) ->
+ Dict = clean_non_sharable(Dict0),
+ share_1(Is, Dict, [I|Seq], Acc);
+share_1([{try_case,_}=I|Is], Dict0, Seq, Acc) ->
+ Dict = clean_non_sharable(Dict0),
+ share_1(Is, Dict, [I|Seq], Acc);
+share_1([{catch_end,_}=I|Is], Dict0, Seq, Acc) ->
+ Dict = clean_non_sharable(Dict0),
+ share_1(Is, Dict, [I|Seq], Acc);
+share_1([I|Is], Dict, Seq, Acc) ->
case is_unreachable_after(I) of
false ->
- share_1(Is, Dict, Lbls, [I|Seq], Acc);
+ share_1(Is, Dict, [I|Seq], Acc);
true ->
- share_1(Is, Dict, Lbls, [I], Acc)
+ share_1(Is, Dict, [I], Acc)
end.
-clean_non_sharable(Dict0, Lbls0) ->
+clean_non_sharable(Dict) ->
%% We are passing in or out of a 'catch' or 'try' block. Remove
%% sequences that should not be shared over the boundaries of the
%% block. Since the end of the sequence must match, the only
@@ -203,17 +198,7 @@ clean_non_sharable(Dict0, Lbls0) ->
%% the 'catch'/'try' block is a sequence that ends with an
%% instruction that causes an exception. Any sequence that causes
%% an exception must contain a line/1 instruction.
- Dict1 = maps:to_list(Dict0),
- Lbls1 = maps:to_list(Lbls0),
- {Dict2,Lbls2} = foldl(fun({K, V}, {Dict,Lbls}) ->
- case sharable_with_try(K) of
- true ->
- {[{K,V}|Dict],lists:keydelete(V, 2, Lbls)};
- false ->
- {Dict,Lbls}
- end
- end, {[],Lbls1}, Dict1),
- {maps:from_list(Dict2),maps:from_list(Lbls2)}.
+ maps:filter(fun(K, _V) -> sharable_with_try(K) end, Dict).
sharable_with_try([{line,_}|_]) ->
%% This sequence may cause an exception and may potentially