diff options
Diffstat (limited to 'lib/compiler')
| -rw-r--r-- | lib/compiler/src/beam_jump.erl | 13 | ||||
| -rw-r--r-- | lib/compiler/test/beam_jump_SUITE.erl | 47 |
2 files changed, 50 insertions, 10 deletions
diff --git a/lib/compiler/src/beam_jump.erl b/lib/compiler/src/beam_jump.erl index fbff4cfd79..d694bd2a5b 100644 --- a/lib/compiler/src/beam_jump.erl +++ b/lib/compiler/src/beam_jump.erl @@ -196,22 +196,19 @@ no_fallthrough([I|_]) -> is_unreachable_after(I). already_has_value(Lit, Lbl, Reg, D) -> - Key = {Lbl,Reg}, case D of - #{Lbl:=unsafe} -> - false; - #{Key:=Lit} -> + #{Lbl:={Reg,Lit}} -> true; #{} -> false end. update_value_dict([Lit,{f,Lbl}|T], Reg, D0) -> - Key = {Lbl,Reg}, D = case D0 of - #{Key := inconsistent} -> D0; - #{Key := _} -> D0#{Key := inconsistent}; - _ -> D0#{Key => Lit} + #{Lbl:=unsafe} -> D0; + #{Lbl:={Reg,Lit}} -> D0; + #{Lbl:=_} -> D0#{Lbl:=unsafe}; + #{} -> D0#{Lbl=>{Reg,Lit}} end, update_value_dict(T, Reg, D); update_value_dict([], _, D) -> D. diff --git a/lib/compiler/test/beam_jump_SUITE.erl b/lib/compiler/test/beam_jump_SUITE.erl index c61e4ab65c..f6cddbf1b1 100644 --- a/lib/compiler/test/beam_jump_SUITE.erl +++ b/lib/compiler/test/beam_jump_SUITE.erl @@ -21,7 +21,8 @@ -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]). + undefined_label/1,ambiguous_catch_try_state/1, + unsafe_move_elimination/1]). suite() -> [{ct_hooks,[ts_install_cth]}]. @@ -32,7 +33,8 @@ all() -> groups() -> [{p,[parallel], [undefined_label, - ambiguous_catch_try_state + ambiguous_catch_try_state, + unsafe_move_elimination ]}]. init_per_suite(Config) -> @@ -72,3 +74,44 @@ river() -> song. 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(left, right, false), + {{false,right,false},false} = unsafe_move_elimination(false, right, true), + {{true,right,right},right} = unsafe_move_elimination(true, right, true), + ok. + +unsafe_move_elimination(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}. + + +id(I) -> + I. |