From 50d8a8b1b0b46d35564ca1c949039ec903cd0937 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micha=C5=82=20Muska=C5=82a?= Date: Sun, 13 Aug 2017 18:24:54 +0200 Subject: Enhance optimisations in beam_peep When cleaning selects, it might happen we're left with only one pair. In such case convert to a regular test + jump. --- lib/compiler/src/beam_peep.erl | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) (limited to 'lib/compiler/src/beam_peep.erl') diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl index 6df5c02334..9436c20b36 100644 --- a/lib/compiler/src/beam_peep.erl +++ b/lib/compiler/src/beam_peep.erl @@ -89,15 +89,37 @@ peep([{gc_bif,_,_,_,_,Dst}=I|Is], SeenTests0, Acc) -> peep([{jump,{f,L}},{label,L}=I|Is], _, Acc) -> %% Sometimes beam_jump has missed this optimization. peep(Is, gb_sets:empty(), [I|Acc]); -peep([{select,Op,R,F,Vls0}|Is], _, Acc) -> +peep([{select,Op,R,F,Vls0}|Is], SeenTests0, Acc0) -> case prune_redundant_values(Vls0, F) of [] -> %% No values left. Must convert to plain jump. I = {jump,F}, - peep(Is, gb_sets:empty(), [I|Acc]); + peep([I|Is], gb_sets:empty(), Acc0); + [{atom,_}=Value,Lbl] when Op =:= select_val -> + %% Single value left. Convert to regular test and pop redundant tests. + Is1 = [{test,is_eq_exact,F,[R,Value]},{jump,Lbl}|Is], + case Acc0 of + [{test,is_atom,F,[R]}|Acc] -> + peep(Is1, SeenTests0, Acc); + _ -> + peep(Is1, SeenTests0, Acc0) + end; + [{integer,_}=Value,Lbl] when Op =:= select_val -> + %% Single value left. Convert to regular test and pop redundant tests. + Is1 = [{test,is_eq_exact,F,[R,Value]},{jump,Lbl}|Is], + case Acc0 of + [{test,is_integer,F,[R]}|Acc] -> + peep(Is1, SeenTests0, Acc); + _ -> + peep(Is1, SeenTests0, Acc0) + end; + [Arity,Lbl] when Op =:= select_tuple_arity -> + %% Single value left. Convert to regular test + Is1 = [{test,test_arity,F,[R,Arity]},{jump,Lbl}|Is], + peep(Is1, SeenTests0, Acc0); [_|_]=Vls -> I = {select,Op,R,F,Vls}, - peep(Is, gb_sets:empty(), [I|Acc]) + peep(Is, gb_sets:empty(), [I|Acc0]) end; peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) -> case beam_utils:is_pure_test(I) of -- cgit v1.2.3