diff options
Diffstat (limited to 'lib/compiler')
| -rw-r--r-- | lib/compiler/src/beam_dead.erl | 24 | ||||
| -rw-r--r-- | lib/compiler/src/beam_peep.erl | 28 |
2 files changed, 21 insertions, 31 deletions
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index ead88b57e9..0cb5040177 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -242,8 +242,15 @@ backward([{select,select_val,Reg,{f,Fail0},List0}|Is], D, Acc) -> List = shortcut_select_list(List0, Reg, D, []), Fail1 = shortcut_label(Fail0, D), Fail = shortcut_bs_test(Fail1, Is, D), - Sel = {select,select_val,Reg,{f,Fail},List}, - backward(Is, D, [Sel|Acc]); + case List of + [{atom,B1},F,{atom,B2},F] when B1 =:= not B2 -> + Test = {test,is_boolean,{f,Fail},[Reg]}, + Jump = {jump,F}, + backward([Jump,Test|Is], D, Acc); + [_|_] -> + Sel = {select,select_val,Reg,{f,Fail},List}, + backward(Is, D, [Sel|Acc]) + end; backward([{jump,{f,To0}},{move,Src,Reg}=Move|Is], D, Acc) -> To = shortcut_select_label(To0, Reg, Src, D), Jump = {jump,{f,To}}, @@ -295,7 +302,18 @@ backward([{test,Op,{f,To0},Ops0}|Is], D, Acc) -> is_eq_exact -> combine_eqs(To, Ops0, D, Acc); _ -> {test,Op,{f,To},Ops0} end, - backward(Is, D, [I|Acc]); + case {I,Acc} of + {{test,is_atom,Fail,Ops0},[{test,is_boolean,Fail,Ops0}|_]} -> + %% An is_atom test before an is_boolean test (with the + %% same failure label) is redundant. + backward(Is, D, Acc); + {{test,_,_,_},_} -> + %% Still a test instruction. Done. + backward(Is, D, [I|Acc]); + {_,_} -> + %% Rewritten to a select_val. Rescan. + backward([I|Is], D, Acc) + end; backward([{test,Op,{f,To0},Live,Ops0,Dst}|Is], D, Acc) -> To1 = shortcut_bs_test(To0, Is, D), To2 = shortcut_label(To1, D), diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl index 17fd2e502a..75be86b83f 100644 --- a/lib/compiler/src/beam_peep.erl +++ b/lib/compiler/src/beam_peep.erl @@ -65,18 +65,6 @@ function({function,Name,Arity,CLabel,Is0}) -> %% InEncoding =:= latin1, OutEncoding =:= unicode; %% InEncoding =:= latin1, OutEncoding =:= utf8 -> %% -%% (2) A select_val/4 instruction that only verifies that -%% its argument is either 'true' or 'false' can be -%% be replaced with an is_boolean/2 instruction. That is: -%% -%% select_val Reg Fail [ true Next false Next ] -%% Next: ... -%% -%% can be rewritten to -%% -%% is_boolean Fail Reg -%% Next: ... -%% peep(Is) -> peep(Is, gb_sets:empty(), []). @@ -95,12 +83,6 @@ peep([{gc_bif,_,_,_,_,Dst}=I|Is], SeenTests0, Acc) -> %% Kill all remembered tests that depend on the destination register. SeenTests = kill_seen(Dst, SeenTests0), peep(Is, SeenTests, [I|Acc]); -peep([{test,is_boolean,{f,Fail},Ops}|_]=Is, SeenTests, - [{test,is_atom,{f,Fail},Ops}|Acc]) -> - %% The previous is_atom/2 test (with the same failure label) is redundant. - %% (If is_boolean(Src) is true, is_atom(Src) is also true, so it is - %% OK to still remember that we have seen is_atom/1.) - peep(Is, SeenTests, Acc); peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) -> case beam_utils:is_pure_test(I) of false -> @@ -121,16 +103,6 @@ peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) -> peep(Is, SeenTests, [I|Acc]) end end; -peep([{select,select_val,Src,Fail, - [{atom,false},{f,L},{atom,true},{f,L}]}| - [{label,L}|_]=Is], SeenTests, Acc) -> - I = {test,is_boolean,Fail,[Src]}, - peep([I|Is], SeenTests, Acc); -peep([{select,select_val,Src,Fail, - [{atom,true},{f,L},{atom,false},{f,L}]}| - [{label,L}|_]=Is], SeenTests, Acc) -> - I = {test,is_boolean,Fail,[Src]}, - peep([I|Is], SeenTests, Acc); peep([I|Is], _, Acc) -> %% An unknown instruction. Throw away all information we %% have collected about test instructions. |