From 4ed58c9dead7e7857b43e5313f1337a5214ba551 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Sat, 20 Dec 2014 20:16:57 +0100 Subject: Generalize optimizations using shortcut_rel_op/4 Better optimizations with less code. --- lib/compiler/src/beam_dead.erl | 72 ++++++++---------------------------------- 1 file changed, 13 insertions(+), 59 deletions(-) (limited to 'lib') 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) -> -- cgit v1.2.3