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authorJohn Högberg <[email protected]>2018-05-08 08:52:22 +0200
committerJohn Högberg <[email protected]>2018-09-28 11:31:57 +0200
commitfd6246c5191d07b80bc7100b470a37a338accecd (patch)
tree9cd0a6750aa0fa680fc214b6650006f34d2e3818 /lib/compiler/test/bs_match_SUITE.erl
parentb1726b022ad260497a1edc1cceb94935a06804e5 (diff)
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Rewrite BSM optimizations in the new SSA-based intermediate format
This commit improves the bit-syntax match optimization pass, leveraging the new SSA intermediate format to perform much more aggressive optimizations. Some highlights: * Watch contexts can be reused even after being passed to a function or being used in a try block. * Sub-binaries are no longer eagerly extracted, making it far easier to keep "happy paths" free from binary creation. * Trivial wrapper functions no longer disable context reuse.
Diffstat (limited to 'lib/compiler/test/bs_match_SUITE.erl')
-rw-r--r--lib/compiler/test/bs_match_SUITE.erl99
1 files changed, 96 insertions, 3 deletions
diff --git a/lib/compiler/test/bs_match_SUITE.erl b/lib/compiler/test/bs_match_SUITE.erl
index b4277f0705..e654979a96 100644
--- a/lib/compiler/test/bs_match_SUITE.erl
+++ b/lib/compiler/test/bs_match_SUITE.erl
@@ -40,7 +40,9 @@
map_and_binary/1,unsafe_branch_caching/1,
bad_literals/1,good_literals/1,constant_propagation/1,
parse_xml/1,get_payload/1,escape/1,num_slots_different/1,
- beam_bsm/1,guard/1,is_ascii/1,non_opt_eq/1,erl_689/1]).
+ beam_bsm/1,guard/1,is_ascii/1,non_opt_eq/1,
+ expression_before_match/1,erl_689/1,restore_on_call/1,
+ restore_after_catch/1,matches_on_parameter/1,big_positions/1]).
-export([coverage_id/1,coverage_external_ignore/2]).
@@ -56,7 +58,7 @@ all() ->
[{group,p}].
groups() ->
- [{p,[parallel],
+ [{p,[],
[size_shadow,int_float,otp_5269,null_fields,wiger,
bin_tail,save_restore,
partitioned_bs_match,function_clause,unit,
@@ -72,7 +74,9 @@ groups() ->
map_and_binary,unsafe_branch_caching,
bad_literals,good_literals,constant_propagation,parse_xml,
get_payload,escape,num_slots_different,
- beam_bsm,guard,is_ascii,non_opt_eq,erl_689]}].
+ beam_bsm,guard,is_ascii,non_opt_eq,
+ expression_before_match,erl_689,restore_on_call,
+ matches_on_parameter,big_positions]}].
init_per_suite(Config) ->
@@ -1764,4 +1768,93 @@ do_erl_689_2(_, <<Length, Data/binary>>) ->
check(F, R) ->
R = F().
+%% Make sure that an expression that comes between function start and a match
+%% expression passes validation.
+expression_before_match(Config) when is_list(Config) ->
+ <<_,R/binary>> = id(<<0,1,2,3>>),
+ {1, <<2,3>>} = expression_before_match_1(R),
+ ok.
+
+expression_before_match_1(R) ->
+ A = id(1),
+ case R of
+ <<1,Bar/binary>> -> {A, Bar};
+ <<>> -> {A, baz}
+ end.
+
+%% Make sure that context positions are updated on calls.
+restore_on_call(Config) when is_list(Config) ->
+ ok = restore_on_call_1(<<0, 1, 2>>).
+
+restore_on_call_1(<<0, Rest/binary>>) ->
+ <<2>> = restore_on_call_2(Rest),
+ <<2>> = restore_on_call_2(Rest), %% {badmatch, <<>>} on missing restore.
+ ok.
+
+restore_on_call_2(<<1, Rest/binary>>) -> Rest;
+restore_on_call_2(Other) -> Other.
+
+%% 'catch' must invalidate positions.
+restore_after_catch(Config) when is_list(Config) ->
+ <<0, 1>> = restore_after_catch_1(<<0, 1>>),
+ ok.
+
+restore_after_catch_1(<<A/binary>>) ->
+ try throw_after_byte(A) of
+ _ -> impossible
+ catch
+ throw:_Any ->
+ %% Will equal <<1>> if the bug is present.
+ A
+ end.
+
+throw_after_byte(<<_,_/binary>>) ->
+ throw(away).
+
+matches_on_parameter(Config) when is_list(Config) ->
+ %% This improves coverage for matching on "naked" parameters.
+ {<<"urka">>, <<"a">>} = matches_on_parameter_1(<<"gurka">>),
+ ok = (catch matches_on_parameter_2(<<"10001110101">>, 0)).
+
+matches_on_parameter_1(Bin) ->
+ <<"g", A/binary>> = Bin,
+ <<_,_,"rk", B/binary>> = Bin,
+ {A, B}.
+
+matches_on_parameter_2(Bin, Offset) ->
+ <<_:Offset, Bit:1, Rest/bits>> = Bin,
+ case bit_size(Rest) of
+ 0 -> throw(ok);
+ _ -> [Bit | matches_on_parameter_2(Bin, Offset + 1)]
+ end.
+
+big_positions(Config) when is_list(Config) ->
+ %% This provides coverage for when match context positions no longer fit
+ %% into an immediate on 32-bit platforms.
+
+ A = <<0:((1 bsl 27) - 8), $A, 1:1, "gurka", $A>>,
+ B = <<0:((1 bsl 27) - 8), $B, "hello", $B>>,
+
+ {a,$A} = bp_start_match(A),
+ {b,$B} = bp_start_match(B),
+ {a,$A} = bp_getpos(A),
+ {b,$B} = bp_getpos(B),
+
+ ok.
+
+%% After the first iteration the context's position will no longer fit into an
+%% immediate. To improve performance the bs_start_match3 instruction will
+%% return a new context with an updated base position so that we won't have to
+%% resort to using bigints.
+bp_start_match(<<_:(1 bsl 27),T/bits>>) -> bp_start_match(T);
+bp_start_match(<<1:1,"gurka",A>>) -> {a,A};
+bp_start_match(<<"hello",B>>) -> {b,B}.
+
+%% This is a corner case where the above didn't work perfectly; if the position
+%% was _just_ small enough to fit into an immediate when bs_start_match3 was
+%% hit, but too large at bs_get_position, then it must be saved as a bigint.
+bp_getpos(<<_:((1 bsl 27) - 8),T/bits>>) -> bp_getpos(T);
+bp_getpos(<<A,1:1,"gurka",A>>) -> {a,A};
+bp_getpos(<<B,"hello",B>>) -> {b,B}.
+
id(I) -> I.