From 808e43007754cb68dbe947ec6752698167b1c470 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 21 Apr 2015 18:00:27 +0200 Subject: beam_utils: Teach check_liveness/3 to understand get_map_elements Understanding get_map_elements improves the stack trimming done by beam_trim. --- lib/compiler/src/beam_utils.erl | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index fca13497ba..a0132b99e3 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -468,6 +468,22 @@ check_liveness(R, [{loop_rec_end,{f,Fail}}|_], St) -> check_liveness_at(R, Fail, St); check_liveness(R, [{line,_}|Is], St) -> check_liveness(R, Is, St); +check_liveness(R, [{get_map_elements,{f,Fail},S,{list,L}}|Is], St0) -> + {Ss,Ds} = split_even(L), + case member(R, [S|Ss]) of + true -> + {used,St0}; + false -> + case check_liveness_at(R, Fail, St0) of + {killed,St}=Killed -> + case member(R, Ds) of + true -> Killed; + false -> check_liveness(R, Is, St) + end; + Other -> + Other + end + end; check_liveness(_R, Is, St) when is_list(Is) -> %% case Is of %% [I|_] -> -- cgit v1.2.3