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authorBjörn Gustavsson <[email protected]>2015-01-11 15:05:05 +0100
committerBjörn Gustavsson <[email protected]>2015-03-09 09:59:37 +0100
commite72e049f25dc001111a6a98ea95a3e7bc3c53c1b (patch)
tree47d4d712d97716e1e47667bfd61ab7cd2d9de1d4 /lib/compiler/src
parent8997433288cb571f155c509f402d0ba4fdba5025 (diff)
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beam_peep: Optimize away redundant use of is_boolean tests
Diffstat (limited to 'lib/compiler/src')
-rw-r--r--lib/compiler/src/beam_peep.erl15
1 files changed, 12 insertions, 3 deletions
diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl
index 97a8c7ba70..5abacc8d5d 100644
--- a/lib/compiler/src/beam_peep.erl
+++ b/lib/compiler/src/beam_peep.erl
@@ -108,14 +108,14 @@ peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) ->
%% has succeeded.
peep(Is, gb_sets:empty(), [I|Acc]);
true ->
- Test = {Op,Ops},
- case gb_sets:is_element(Test, SeenTests0) of
+ case is_test_redundant(Op, Ops, SeenTests0) of
true ->
- %% This test has already succeeded and
+ %% This test or a similar test has already succeeded and
%% is therefore redundant.
peep(Is, SeenTests0, Acc);
false ->
%% Remember that we have seen this test.
+ Test = {Op,Ops},
SeenTests = gb_sets:insert(Test, SeenTests0),
peep(Is, SeenTests, [I|Acc])
end
@@ -136,6 +136,15 @@ peep([I|Is], _, Acc) ->
peep(Is, gb_sets:empty(), [I|Acc]);
peep([], _, Acc) -> reverse(Acc).
+is_test_redundant(Op, Ops, Seen) ->
+ gb_sets:is_element({Op,Ops}, Seen) orelse
+ is_test_redundant_1(Op, Ops, Seen).
+
+is_test_redundant_1(is_boolean, [R], Seen) ->
+ gb_sets:is_element({is_eq_exact,[R,{atom,false}]}, Seen) orelse
+ gb_sets:is_element({is_eq_exact,[R,{atom,true}]}, Seen);
+is_test_redundant_1(_, _, _) -> false.
+
kill_seen(Dst, Seen0) ->
gb_sets:from_ordset(kill_seen_1(gb_sets:to_list(Seen0), Dst)).