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authorBjörn Gustavsson <bjorn@erlang.org>2016-08-22 12:25:42 +0200
committerBjörn Gustavsson <bjorn@erlang.org>2016-08-22 12:25:42 +0200
commitbe3cd8376767967f1bc7079ca4fa0d1c136247a8 (patch)
tree537cdbde4a21f09345b38bdf5b5c75624c4f12ea
parent891d81174d43fb353bf3031f0c83d6f9af92bb0b (diff)
parenta66a2e84ec4c6fb7c19affe43134570caabe8569 (diff)
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Merge branch 'bjorn/compiler/binary-literal-matching'
* bjorn/compiler/binary-literal-matching: Reinstate optimization of binary literal matching Strengthen test case added in 8b83bc0b
-rw-r--r--lib/compiler/src/beam_dead.erl23
-rw-r--r--lib/compiler/test/match_SUITE.erl10
2 files changed, 30 insertions, 3 deletions
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl
index 6f6d742293..3606af9d75 100644
--- a/lib/compiler/src/beam_dead.erl
+++ b/lib/compiler/src/beam_dead.erl
@@ -272,14 +272,18 @@ 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,
+backward([{test,bs_start_match2,F,Live,[R,_]=Args,Ctxt}|Is], D,
[{test,bs_match_string,F,[Ctxt,Bs]},
{test,bs_test_tail2,F,[Ctxt,0]}|Acc0]=Acc) ->
+ {f,To0} = F,
case beam_utils:is_killed(Ctxt, Acc0, D) of
true ->
- Eq = {test,is_eq_exact,F,[R,{literal,Bs}]},
+ To = shortcut_bs_context_to_binary(To0, R, D),
+ Eq = {test,is_eq_exact,{f,To},[R,{literal,Bs}]},
backward(Is, D, [Eq|Acc0]);
false ->
+ To = shortcut_bs_start_match(To0, R, D),
+ I = {test,bs_start_match2,{f,To},Live,Args,Ctxt},
backward(Is, D, [I|Acc])
end;
backward([{test,bs_start_match2,{f,To0},Live,[Src|_]=Info,Dst}|Is], D, Acc) ->
@@ -551,6 +555,21 @@ shortcut_bs_start_match_1([{test,bs_start_match2,{f,To},_,[Reg|_],_}|_],
shortcut_bs_start_match_1(_, _, To, _) ->
To.
+%% shortcut_bs_context_to_binary(TargetLabel, Reg) -> TargetLabel
+%% If a bs_start_match2 instruction has been eliminated, the
+%% bs_context_to_binary instruction can be eliminated too.
+
+shortcut_bs_context_to_binary(To, Reg, D) ->
+ shortcut_bs_ctb_1(beam_utils:code_at(To, D), Reg, To, D).
+
+shortcut_bs_ctb_1([{bs_context_to_binary,Reg}|Is], Reg, To, D) ->
+ shortcut_bs_ctb_1(Is, Reg, To, D);
+shortcut_bs_ctb_1([{jump,{f,To}}|_], Reg, _, D) ->
+ Code = beam_utils:code_at(To, D),
+ shortcut_bs_ctb_1(Code, Reg, To, D);
+shortcut_bs_ctb_1(_, _, To, _) ->
+ To.
+
%% shortcut_rel_op(FailLabel, Operator, [Operand], D) -> FailLabel'
%% Try to shortcut the given test instruction. Example:
%%
diff --git a/lib/compiler/test/match_SUITE.erl b/lib/compiler/test/match_SUITE.erl
index 127679ba69..52b2da05f7 100644
--- a/lib/compiler/test/match_SUITE.erl
+++ b/lib/compiler/test/match_SUITE.erl
@@ -576,7 +576,15 @@ grab_bag_remove_failure([{stretch,_,Mi}=Stretch | Specs], Unit, _MaxFailure) ->
%% Regression in 19.0, reported by Alexei Sholik
literal_binary(_Config) ->
- 3 = literal_binary_match(bar,<<"y">>),
+ 3 = literal_binary_match(bar, <<"y">>),
+
+ %% While we are at it, also test the remaining code paths
+ %% in literal_binary_match/2.
+ 1 = literal_binary_match(bar, <<"x">>),
+ 2 = literal_binary_match(foo, <<"x">>),
+ 3 = literal_binary_match(foo, <<"y">>),
+ fail = literal_binary_match(bar, <<"z">>),
+ fail = literal_binary_match(foo, <<"z">>),
ok.
literal_binary_match(bar, <<"x">>) -> 1;