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-rw-r--r--lib/compiler/test/beam_jump_SUITE.erl125
1 files changed, 123 insertions, 2 deletions
diff --git a/lib/compiler/test/beam_jump_SUITE.erl b/lib/compiler/test/beam_jump_SUITE.erl
index faedc0c1f1..a456f31d79 100644
--- a/lib/compiler/test/beam_jump_SUITE.erl
+++ b/lib/compiler/test/beam_jump_SUITE.erl
@@ -22,7 +22,8 @@
-export([all/0,suite/0,groups/0,init_per_suite/1,end_per_suite/1,
init_per_group/2,end_per_group/2,
undefined_label/1,ambiguous_catch_try_state/1,
- build_tuple/1]).
+ unsafe_move_elimination/1,build_tuple/1,
+ coverage/1]).
suite() ->
[{ct_hooks,[ts_install_cth]}].
@@ -34,7 +35,9 @@ groups() ->
[{p,[parallel],
[undefined_label,
ambiguous_catch_try_state,
- build_tuple
+ unsafe_move_elimination,
+ build_tuple,
+ coverage
]}].
init_per_suite(Config) ->
@@ -75,6 +78,82 @@ checks(Wanted) ->
%% Must be one line to cause the unsafe optimization.
{catch case river() of sheet -> begin +Wanted, if "da" -> Wanted end end end, catch case river() of sheet -> begin + Wanted, if "da" -> Wanted end end end}.
+unsafe_move_elimination(_Config) ->
+ {{left,right,false},false} = unsafe_move_elimination_1(left, right, false),
+ {{false,right,false},false} = unsafe_move_elimination_1(false, right, true),
+ {{true,right,right},right} = unsafe_move_elimination_1(true, right, true),
+ [ok = unsafe_move_elimination_2(I) || I <- lists:seq(0,16)],
+ ok.
+
+unsafe_move_elimination_1(Left, Right, Simple0) ->
+ id(1),
+
+ %% The move at label 29 would be removed by beam_jump, which is unsafe because
+ %% the two select_val instructions have different source registers.
+ %%
+ %% {select_val,{y,0},{f,25},{list,[{atom,true},{f,27},{atom,false},{f,29}]}}.
+ %% ^^^^^ ^^^^^^^^^^^^^^^^^^^
+ %% {label,27}.
+ %% {kill,{y,0}}.
+ %% {move,{y,2},{x,0}}.
+ %% {line,...}.
+ %% {call,1,{f,31}}.
+ %% {select_val,{x,0},{f,33},{list,[{atom,true},{f,35},{atom,false},{f,29}]}}.
+ %% ^^^^^ ^^^^^^^^^^^^^^^^^^^
+ %% {label,29}.
+ %% {move,{atom,false},{y,0}}. <=== REMOVED (unsafely).
+ %% {jump,{f,37}}.
+
+ Simple = case case Simple0 of
+ false -> false;
+ true -> id(Left)
+ end
+ of
+ false ->
+ false;
+ true ->
+ id(Right)
+ end,
+ {id({Left,Right,Simple}),Simple}.
+
+unsafe_move_elimination_2(Int) ->
+ %% The type optimization pass would recognize that TagInt can only be
+ %% [0 .. 7], so the first 'case' would select_val over [0 .. 6] and swap
+ %% out the fail label with the block for 7.
+ %%
+ %% A later optimization would merge this block with 'expects_h' in the
+ %% second case, as the latter is only reachable from the former.
+ %%
+ %% ... but this broke down when the move elimination optimization didn't
+ %% take the fail label of the first select_val into account. This caused it
+ %% to believe that the only way to reach 'expects_h' was through the second
+ %% case when 'Tag' =:= 'h', which made it remove the move instruction
+ %% added in the first case, passing garbage to expects_h/2.
+ TagInt = Int band 2#111,
+ Tag = case TagInt of
+ 0 -> a;
+ 1 -> b;
+ 2 -> c;
+ 3 -> d;
+ 4 -> e;
+ 5 -> f;
+ 6 -> g;
+ 7 -> h
+ end,
+ case Tag of
+ g -> expects_g(TagInt, Tag);
+ h -> expects_h(TagInt, Tag);
+ _ -> Tag = id(Tag), ok
+ end.
+
+expects_g(6, Atom) ->
+ Atom = id(g),
+ ok.
+
+expects_h(7, Atom) ->
+ Atom = id(h),
+ ok.
+
-record(message2, {id, p1}).
-record(message3, {id, p1, p2}).
@@ -87,3 +166,45 @@ do_build_tuple(Message) ->
Res = {res, rand:uniform(100)},
{Message#message3.id, Res}
end.
+
+coverage(_Config) ->
+ ok = coverage_1(ok),
+ {error,badarg} = coverage_1({error,badarg}),
+
+ gt = coverage_2(100, 42),
+ le = coverage_2(100, 999),
+ le = coverage_2([], []),
+ gt = coverage_2([], xxx),
+
+ ok.
+
+coverage_1(Var) ->
+ case id(Var) of
+ ok -> ok;
+ Error -> Error
+ end.
+
+%% Cover beam_jump:invert_test(is_ne_exact).
+coverage_2(Pre1, Pre2) ->
+ case
+ case Pre1 == [] of
+ false ->
+ false;
+ true ->
+ Pre2 /= []
+ end
+ of
+ true ->
+ gt;
+ false ->
+ case Pre1 > Pre2 of
+ true ->
+ gt;
+ false ->
+ le
+ end
+ end.
+
+
+id(I) ->
+ I.