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authorBjörn Gustavsson <[email protected]>2015-04-15 09:59:05 +0200
committerBjörn Gustavsson <[email protected]>2015-04-22 10:14:55 +0200
commit37225949b6cf177934848fff21a1a551b7f6faee (patch)
tree090c584959ca6736df3ccd79e5df6dbebf50be87
parent2e2d583a49939026ec9b959f9b7941d3c2d084f2 (diff)
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beam_block: Optimize matching of binary literals
When matching a binary literal as in: <<"abc">> = Bin the compiler will produce a sequence of three instructions (some details in the instructions removed for simplicity): bs_start_match2 Fail BinReg CtxtReg bs_match_string Fail CtxtReg "abc" bs_test_tail2 Fail CtxtReg 0 The sequence can be replaced with: is_eq_exact Fail BinReg "abc"
-rw-r--r--lib/compiler/src/beam_dead.erl10
-rw-r--r--lib/compiler/test/bs_match_SUITE.erl14
2 files changed, 22 insertions, 2 deletions
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl
index adc3cebc62..5932d8ce1d 100644
--- a/lib/compiler/src/beam_dead.erl
+++ b/lib/compiler/src/beam_dead.erl
@@ -255,6 +255,16 @@ backward([{jump,{f,To}}=J|[{bif,Op,_,Ops,Reg}|Is]=Is0], D, Acc) ->
catch
throw:not_possible -> backward(Is0, D, [J|Acc])
end;
+backward([{test,bs_start_match2,F,_,[R,_],Ctxt}=I|Is], D,
+ [{test,bs_match_string,F,[Ctxt,Bs]},
+ {test,bs_test_tail2,F,[Ctxt,0]}|Acc0]=Acc) ->
+ case beam_utils:is_killed(Ctxt, Acc0, D) of
+ true ->
+ Eq = {test,is_eq_exact,F,[R,{literal,Bs}]},
+ backward(Is, D, [Eq|Acc0]);
+ false ->
+ backward(Is, D, [I|Acc])
+ end;
backward([{test,bs_start_match2,{f,To0},Live,[Src|_]=Info,Dst}|Is], D, Acc) ->
To = shortcut_bs_start_match(To0, Src, D),
I = {test,bs_start_match2,{f,To},Live,Info,Dst},
diff --git a/lib/compiler/test/bs_match_SUITE.erl b/lib/compiler/test/bs_match_SUITE.erl
index 80d80505a6..b54db06339 100644
--- a/lib/compiler/test/bs_match_SUITE.erl
+++ b/lib/compiler/test/bs_match_SUITE.erl
@@ -34,7 +34,8 @@
otp_7188/1,otp_7233/1,otp_7240/1,otp_7498/1,
match_string/1,zero_width/1,bad_size/1,haystack/1,
cover_beam_bool/1,matched_out_size/1,follow_fail_branch/1,
- no_partition/1,calling_a_binary/1,binary_in_map/1]).
+ no_partition/1,calling_a_binary/1,binary_in_map/1,
+ match_string_opt/1]).
-export([coverage_id/1,coverage_external_ignore/2]).
@@ -59,7 +60,8 @@ groups() ->
matching_and_andalso,otp_7188,otp_7233,otp_7240,
otp_7498,match_string,zero_width,bad_size,haystack,
cover_beam_bool,matched_out_size,follow_fail_branch,
- no_partition,calling_a_binary,binary_in_map]}].
+ no_partition,calling_a_binary,binary_in_map,
+ match_string_opt]}].
init_per_suite(Config) ->
@@ -1214,6 +1216,14 @@ match_binary_in_map(Map) ->
ok
end.
+match_string_opt(Config) when is_list(Config) ->
+ {x,<<1,2,3>>,{<<1>>,{v,<<1,2,3>>}}} =
+ do_match_string_opt({<<1>>,{v,<<1,2,3>>}}),
+ ok.
+
+do_match_string_opt({<<1>>,{v,V}}=T) ->
+ {x,V,T}.
+
check(F, R) ->
R = F().