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authorBjörn Gustavsson <bjorn@erlang.org>2014-12-20 20:16:57 +0100
committerBjörn Gustavsson <bjorn@erlang.org>2015-01-09 13:18:44 +0100
commit4ed58c9dead7e7857b43e5313f1337a5214ba551 (patch)
tree5996a0ed3e3bf30b9d4044823fb90d23b553a47c
parent7b10ff77235532923558a30759ed9b5fe6d994a5 (diff)
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Generalize optimizations using shortcut_rel_op/4
Better optimizations with less code.
-rw-r--r--lib/compiler/src/beam_dead.erl72
1 files changed, 13 insertions, 59 deletions
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl
index 9703b1a847..9c1c60a92e 100644
--- a/lib/compiler/src/beam_dead.erl
+++ b/lib/compiler/src/beam_dead.erl
@@ -286,15 +286,10 @@ backward([{select,select_val,Reg,{f,Fail0},List0}|Is], D, Acc) ->
Fail = shortcut_bs_test(Fail1, Is, D),
Sel = {select,select_val,Reg,{f,Fail},List},
backward(Is, D, [Sel|Acc]);
-backward([{jump,{f,To0}},{move,Src,Reg}=Move0|Is], D, Acc) ->
- {To,Move} = case Src of
- {atom,Val0} ->
- To1 = shortcut_select_label(To0, Reg, Val0, D),
- {To2,Val} = shortcut_boolean_label(To1, Reg, Val0, D),
- {To2,{move,{atom,Val},Reg}};
- _ ->
- {shortcut_label(To0, D),Move0}
- end,
+backward([{jump,{f,To0}},{move,Src0,Reg}|Is], D, Acc) ->
+ To1 = shortcut_select_label(To0, Reg, Src0, D),
+ {To,Src} = shortcut_boolean_label(To1, Reg, Src0, D),
+ Move = {move,Src,Reg},
Jump = {jump,{f,To}},
case beam_utils:is_killed_at(Reg, To, D) of
false -> backward([Move|Is], D, [Jump|Acc]);
@@ -310,11 +305,6 @@ backward([{test,bs_start_match2,{f,To0},Live,[Src|_]=Info,Dst}|Is], D, Acc) ->
To = shortcut_bs_start_match(To0, Src, D),
I = {test,bs_start_match2,{f,To},Live,Info,Dst},
backward(Is, D, [I|Acc]);
-backward([{test,is_eq_exact,{f,To0},[Reg,{atom,Val}]=Ops}|Is], D, Acc) ->
- To1 = shortcut_bs_test(To0, Is, D),
- To = shortcut_fail_label(To1, Reg, Val, D),
- I = combine_eqs(To, Ops, D, Acc),
- backward(Is, D, [I|Acc]);
backward([{test,Op,{f,To0},Ops0}|Is], D, Acc) ->
To1 = shortcut_bs_test(To0, Is, D),
To2 = shortcut_label(To1, D),
@@ -378,8 +368,8 @@ equal_ops([Op|T0], [Op|T1]) ->
equal_ops([], []) -> true;
equal_ops(_, _) -> false.
-shortcut_select_list([{_,Val}=Lit,{f,To0}|T], Reg, D, Acc) ->
- To = shortcut_select_label(To0, Reg, Val, D),
+shortcut_select_list([Lit,{f,To0}|T], Reg, D, Acc) ->
+ To = shortcut_select_label(To0, Reg, Lit, D),
shortcut_select_list(T, Reg, D, [{f,To},Lit|Acc]);
shortcut_select_list([], _, _, Acc) -> reverse(Acc).
@@ -389,58 +379,22 @@ shortcut_label(To0, D) ->
_ -> To0
end.
-shortcut_select_label(To0, Reg, Val, D) ->
- case beam_utils:code_at(To0, D) of
- [{jump,{f,To}}|_] ->
- shortcut_select_label(To, Reg, Val, D);
- [{test,is_atom,_,[Reg]},{select,select_val,Reg,{f,Fail},Map}|_] ->
- To = find_select_val(Map, Val, Fail),
- shortcut_select_label(To, Reg, Val, D);
- [{test,is_eq_exact,{f,_},[Reg,{atom,Val}]},{label,To}|_] when is_atom(Val) ->
- shortcut_select_label(To, Reg, Val, D);
- [{test,is_eq_exact,{f,_},[Reg,{atom,Val}]},{jump,{f,To}}|_] when is_atom(Val) ->
- shortcut_select_label(To, Reg, Val, D);
- [{test,is_eq_exact,{f,To},[Reg,{atom,AnotherVal}]}|_]
- when is_atom(Val), Val =/= AnotherVal ->
- shortcut_select_label(To, Reg, Val, D);
- [{test,is_ne_exact,{f,To},[Reg,{atom,Val}]}|_] when is_atom(Val) ->
- shortcut_select_label(To, Reg, Val, D);
- [{test,is_ne_exact,{f,_},[Reg,{atom,_}]},{label,To}|_] when is_atom(Val) ->
- shortcut_select_label(To, Reg, Val, D);
- [{test,is_tuple,{f,To},[Reg]}|_] when is_atom(Val) ->
- shortcut_select_label(To, Reg, Val, D);
- _ ->
- To0
- end.
-
-shortcut_fail_label(To0, Reg, Val, D) ->
- case beam_utils:code_at(To0, D) of
- [{jump,{f,To}}|_] ->
- shortcut_fail_label(To, Reg, Val, D);
- [{test,is_eq_exact,{f,To},[Reg,{atom,Val}]}|_] when is_atom(Val) ->
- shortcut_fail_label(To, Reg, Val, D);
- _ ->
- To0
- end.
+shortcut_select_label(To, Reg, Lit, D) ->
+ shortcut_rel_op(To, is_ne_exact, [Reg,Lit], D).
-shortcut_boolean_label(To0, Reg, Bool0, D) when is_boolean(Bool0) ->
+shortcut_boolean_label(To0, Reg, {atom,Bool0}=Lit, D) when is_boolean(Bool0) ->
case beam_utils:code_at(To0, D) of
[{line,_},{bif,'not',_,[Reg],Reg},{jump,{f,To}}|_] ->
- Bool = not Bool0,
+ Bool = {atom,not Bool0},
{shortcut_select_label(To, Reg, Bool, D),Bool};
_ ->
- {To0,Bool0}
+ {To0,Lit}
end;
shortcut_boolean_label(To, _, Bool, _) -> {To,Bool}.
-find_select_val([{_,Val},{f,To}|_], Val, _) -> To;
-find_select_val([{_,_}, {f,_}|T], Val, Fail) ->
- find_select_val(T, Val, Fail);
-find_select_val([], _, Fail) -> Fail.
-
replace_comp_op(To, Reg, Op, Ops, D) ->
- False = comp_op_find_shortcut(To, Reg, false, D),
- True = comp_op_find_shortcut(To, Reg, true, D),
+ False = comp_op_find_shortcut(To, Reg, {atom,false}, D),
+ True = comp_op_find_shortcut(To, Reg, {atom,true}, D),
[bif_to_test(Op, Ops, False),{jump,{f,True}}].
comp_op_find_shortcut(To0, Reg, Val, D) ->