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authorBjörn Gustavsson <[email protected]>2015-04-17 11:43:20 +0200
committerBjörn Gustavsson <[email protected]>2015-04-22 10:14:55 +0200
commit84705583c517437f59e5b2b3833e1dc1a693830a (patch)
tree9617620162336cc4013f34a238bf019cc19a6c96 /lib/compiler/src/beam_utils.erl
parent37225949b6cf177934848fff21a1a551b7f6faee (diff)
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beam_utils: Optimize index_labels_1/2
The execution time for beam_utils:index_labels_1/2 is among the longest in the beam_bool, beam_bsm, beam_receive, and beam_trim compiler passes. Therefore it is worthwhile to do the minor optimization of replacing a call to lists:dropwhile/2 with a special-purpose drop_labels function.
Diffstat (limited to 'lib/compiler/src/beam_utils.erl')
-rw-r--r--lib/compiler/src/beam_utils.erl6
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index 7704690f86..fd666be41e 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -612,13 +612,15 @@ is_reg_used_at_1(R, Lbl, St0) ->
end.
index_labels_1([{label,Lbl}|Is0], Acc) ->
- Is = lists:dropwhile(fun({label,_}) -> true;
- (_) -> false end, Is0),
+ Is = drop_labels(Is0),
index_labels_1(Is0, [{Lbl,Is}|Acc]);
index_labels_1([_|Is], Acc) ->
index_labels_1(Is, Acc);
index_labels_1([], Acc) -> gb_trees:from_orddict(sort(Acc)).
+drop_labels([{label,_}|Is]) -> drop_labels(Is);
+drop_labels(Is) -> Is.
+
%% Help functions for combine_heap_needs.
combine_alloc_lists(Al1, Al2) ->