diff options
| -rw-r--r-- | lib/compiler/src/beam_jump.erl | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/lib/compiler/src/beam_jump.erl b/lib/compiler/src/beam_jump.erl index 4e699c4fbf..52fe0e90ce 100644 --- a/lib/compiler/src/beam_jump.erl +++ b/lib/compiler/src/beam_jump.erl @@ -295,12 +295,6 @@ opt([{test,_,{f,_}=Lbl,_,_,_}=I|Is], Acc, St) -> opt(Is, [I|Acc], label_used(Lbl, St)); opt([{select,_,_R,Fail,Vls}=I|Is], Acc, St) -> skip_unreachable(Is, [I|Acc], label_used([Fail|Vls], St)); -opt([{label,L}=I|Is], Acc, #st{entry=L}=St) -> - %% NEVER move the entry label. - opt(Is, [I|Acc], St); -opt([{label,L1},{jump,{f,L2}}=I|Is], [Prev|Acc], St0) -> - St = St0#st{mlbl=dict:append(L2, L1, St0#st.mlbl)}, - opt([Prev,I|Is], Acc, label_used({f,L2}, St)); opt([{label,Lbl}=I|Is], Acc, #st{mlbl=Mlbl}=St0) -> case dict:find(Lbl, Mlbl) of {ok,Lbls} -> @@ -310,9 +304,20 @@ opt([{label,Lbl}=I|Is], Acc, #st{mlbl=Mlbl}=St0) -> insert_labels([Lbl|Lbls], Is, Acc, St); error -> opt(Is, [I|Acc], St0) end; -opt([{jump,{f,Lbl}},{label,Lbl}=I|Is], Acc, St) -> - opt([I|Is], Acc, St); -opt([{jump,Lbl}=I|Is], Acc, St) -> +opt([{jump,{f,_}=X}|[{label,_},{jump,X}|_]=Is], Acc, St) -> + opt(Is, Acc, St); +opt([{jump,{f,Lbl}}|[{label,Lbl}|_]=Is], Acc, St) -> + opt(Is, Acc, St); +opt([{jump,{f,L}=Lbl}=I|Is], Acc0, #st{mlbl=Mlbl0}=St0) -> + %% All labels before this jump instruction should now be + %% moved to the location of the jump's target. + {Lbls,Acc} = collect_labels(Acc0, St0), + St = case Lbls of + [] -> St0; + [_|_] -> + Mlbl = dict:append_list(L, Lbls, Mlbl0), + St0#st{mlbl=Mlbl} + end, skip_unreachable(Is, [I|Acc], label_used(Lbl, St)); %% Optimization: quickly handle some common instructions that don't %% have any failure labels and where is_unreachable_after(I) =:= false. @@ -349,6 +354,17 @@ insert_fc_labels([L|Ls], Mlbl, Acc0) -> end; insert_fc_labels([], _, Acc) -> Acc. +collect_labels(Is, #st{entry=Entry}) -> + collect_labels_1(Is, Entry, []). + +collect_labels_1([{label,Entry}|_]=Is, Entry, Acc) -> + %% Never move the entry label. + {Acc,Is}; +collect_labels_1([{label,L}|Is], Entry, Acc) -> + collect_labels_1(Is, Entry, [L|Acc]); +collect_labels_1(Is, _Entry, Acc) -> + {Acc,Is}. + %% label_defined(Is, Label) -> true | false. %% Test whether the label Label is defined at the start of the instruction %% sequence, possibly preceeded by other label definitions. |