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authorBjörn Gustavsson <[email protected]>2016-01-07 14:01:32 +0100
committerBjörn Gustavsson <[email protected]>2016-01-07 14:01:32 +0100
commitc0ff4189f752fdfe20b231492b2084dfe8cecdb2 (patch)
tree4c0e3ab8c61be22b97eae34b87ac8377d038a0d9 /lib/compiler
parentdf18cd270ad682cedc8c21990641b0bdb8788092 (diff)
parent7c72e25926e153811ff099057bea649afa0be376 (diff)
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Merge branch 'bjorn/compiler/beam_bool/OTP-13208' into maint
* bjorn/compiler/beam_bool/OTP-13208: beam_bool: Fix unsafe optimization
Diffstat (limited to 'lib/compiler')
-rw-r--r--lib/compiler/src/beam_bool.erl50
-rw-r--r--lib/compiler/test/guard_SUITE.erl27
2 files changed, 27 insertions, 50 deletions
diff --git a/lib/compiler/src/beam_bool.erl b/lib/compiler/src/beam_bool.erl
index 14b6381230..d14be83496 100644
--- a/lib/compiler/src/beam_bool.erl
+++ b/lib/compiler/src/beam_bool.erl
@@ -142,11 +142,6 @@ bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) ->
throw:not_boolean_expr ->
failed;
- %% The block contains a 'move' instruction that could
- %% not be handled.
- throw:move ->
- failed;
-
%% The optimization is not safe. (A register
%% used by the instructions following the
%% optimized code is either not assigned a
@@ -215,37 +210,14 @@ ensure_opt_safe(Bl, NewCode, OldIs, Fail, PrecedingCode, St) ->
false -> throw(all_registers_not_killed);
true -> ok
end,
- Same = assigned_same_value(Bl, NewCode),
MustBeUnused = ordsets:subtract(ordsets:union(NotSet, NewDst),
- ordsets:union(MustBeKilled, Same)),
+ MustBeKilled),
case none_used(MustBeUnused, OldIs, Fail, St) of
false -> throw(registers_used);
true -> ok
end,
ok.
-%% assigned_same_value(OldCode, NewCodeReversed) -> [DestinationRegs]
-%% Return an ordset with a list of all y registers that are always
-%% assigned the same value in the old and new code. Currently, we
-%% are very conservative in that we only consider identical move
-%% instructions in the same order.
-%%
-assigned_same_value(Old, New) ->
- case reverse(New) of
- [{block,Bl}|_] ->
- assigned_same_value(Old, Bl, []);
- _ ->
- ordsets:new()
- end.
-
-assigned_same_value([{set,[{y,_}=D],[S],move}|T1],
- [{set,[{y,_}=D],[S],move}|T2], Acc) ->
- assigned_same_value(T1, T2, [D|Acc]);
-assigned_same_value(_, _, Acc) ->
- ordsets:from_list(Acc).
-
-update_fail_label([{set,_,_,move}=I|Is], Fail, Acc) ->
- update_fail_label(Is, Fail, [I|Acc]);
update_fail_label([{set,Ds,As,{bif,N,{f,_}}}|Is], Fail, Acc) ->
update_fail_label(Is, Fail, [{set,Ds,As,{bif,N,{f,Fail}}}|Acc]);
update_fail_label([{set,Ds,As,{alloc,Regs,{gc_bif,N,{f,_}}}}|Is], Fail, Acc) ->
@@ -314,8 +286,6 @@ split_block_1(Is, Fail, ProhibitFailLabel) ->
end
end.
-split_block_2([{set,_,_,move}=I|Is], Fail, Acc) ->
- split_block_2(Is, Fail, [I|Acc]);
split_block_2([{set,[_],_,{bif,_,{f,Fail}}}=I|Is], Fail, Acc) ->
split_block_2(Is, Fail, [I|Acc]);
split_block_2([{set,[_],_,{alloc,_,{gc_bif,_,{f,Fail}}}}=I|Is], Fail, Acc) ->
@@ -343,8 +313,6 @@ dst_regs([{set,[D],_,{bif,_,{f,_}}}|Is], Acc) ->
dst_regs(Is, [D|Acc]);
dst_regs([{set,[D],_,{alloc,_,{gc_bif,_,{f,_}}}}|Is], Acc) ->
dst_regs(Is, [D|Acc]);
-dst_regs([{set,[D],_,move}|Is], Acc) ->
- dst_regs(Is, [D|Acc]);
dst_regs([_|Is], Acc) ->
dst_regs(Is, Acc);
dst_regs([], Acc) -> ordsets:from_list(Acc).
@@ -411,13 +379,6 @@ bopt_tree([{protected,[Dst],Code,_}|Is], Forest0, Pre) ->
_Res ->
throw(not_boolean_expr)
end;
-bopt_tree([{set,[Dst],[Src],move}=Move|Is], Forest, Pre) ->
- case {Src,Dst} of
- {{tmp,_},_} -> throw(move);
- {_,{tmp,_}} -> throw(move);
- _ -> ok
- end,
- bopt_tree(Is, Forest, [Move|Pre]);
bopt_tree([{set,[Dst],As,{bif,N,_}}=Bif|Is], Forest0, Pre) ->
Ar = length(As),
case safe_bool_op(N, Ar) of
@@ -589,10 +550,6 @@ free_variables(Is) ->
E = gb_sets:empty(),
free_vars_1(Is, E, E, E).
-free_vars_1([{set,Ds,As,move}|Is], F0, N0, A) ->
- F = gb_sets:union(F0, gb_sets:difference(var_list(As), N0)),
- N = gb_sets:union(N0, var_list(Ds)),
- free_vars_1(Is, F, N, A);
free_vars_1([{set,Ds,As,{bif,_,_}}|Is], F0, N0, A) ->
F = gb_sets:union(F0, gb_sets:difference(var_list(As), N0)),
N = gb_sets:union(N0, var_list(Ds)),
@@ -632,8 +589,6 @@ free_vars_regs(X) -> [{x,X-1}|free_vars_regs(X-1)].
rename_regs(Is, Regs) ->
rename_regs(Is, Regs, []).
-rename_regs([{set,_,_,move}=I|Is], Regs, Acc) ->
- rename_regs(Is, Regs, [I|Acc]);
rename_regs([{set,[Dst0],Ss0,{alloc,_,Info}}|Is], Regs0, Acc) ->
Live = live_regs(Regs0),
Ss = rename_sources(Ss0, Regs0),
@@ -737,8 +692,7 @@ ssa_assign({x,_}=R, #ssa{sub=Sub0}=Ssa0) ->
Sub1 = gb_trees:update(R, NewReg, Sub0),
Sub = gb_trees:insert(NewReg, NewReg, Sub1),
Ssa#ssa{sub=Sub}
- end;
-ssa_assign(_, Ssa) -> Ssa.
+ end.
ssa_sub_list(List, Sub) ->
[ssa_sub(E, Sub) || E <- List].
diff --git a/lib/compiler/test/guard_SUITE.erl b/lib/compiler/test/guard_SUITE.erl
index b3b67155b3..3f073d79cb 100644
--- a/lib/compiler/test/guard_SUITE.erl
+++ b/lib/compiler/test/guard_SUITE.erl
@@ -34,7 +34,7 @@
tricky/1,rel_ops/1,rel_op_combinations/1,literal_type_tests/1,
basic_andalso_orelse/1,traverse_dcd/1,
check_qlc_hrl/1,andalso_semi/1,t_tuple_size/1,binary_part/1,
- bad_constants/1,bad_guards/1]).
+ bad_constants/1,bad_guards/1,scotland/1]).
suite() -> [{ct_hooks,[ts_install_cth]}].
@@ -52,7 +52,7 @@ groups() ->
rel_ops,rel_op_combinations,
literal_type_tests,basic_andalso_orelse,traverse_dcd,
check_qlc_hrl,andalso_semi,t_tuple_size,binary_part,
- bad_constants,bad_guards]}].
+ bad_constants,bad_guards,scotland]}].
init_per_suite(Config) ->
Config.
@@ -1831,6 +1831,29 @@ bad_guards_2(M, [_]) when M#{a := 0, b => 0}, map_size(M) ->
bad_guards_3(M, [_]) when is_map(M) andalso M#{a := 0, b => 0}, length(M) ->
ok.
+%% beam_bool would remove the initialization of {y,0}.
+%% (Thanks to Thomas Arts and QuickCheck.)
+
+scotland(_Config) ->
+ million = do_scotland(placed),
+ {'EXIT',{{badmatch,placed},_}} = (catch do_scotland(false)),
+ {'EXIT',{{badmatch,placed},_}} = (catch do_scotland(true)),
+ {'EXIT',{{badmatch,placed},_}} = (catch do_scotland(echo)),
+ ok.
+
+do_scotland(Echo) ->
+ found(case Echo of
+ Echo when true; Echo, Echo, Echo ->
+ Echo;
+ echo ->
+ []
+ end,
+ Echo = placed).
+
+found(_, _) -> million.
+
+
+
%% Call this function to turn off constant propagation.
id(I) -> I.