diff options
Diffstat (limited to 'lib/compiler/test/beam_ssa_SUITE.erl')
| -rw-r--r-- | lib/compiler/test/beam_ssa_SUITE.erl | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/lib/compiler/test/beam_ssa_SUITE.erl b/lib/compiler/test/beam_ssa_SUITE.erl index 669ce6f5cf..3b510f3528 100644 --- a/lib/compiler/test/beam_ssa_SUITE.erl +++ b/lib/compiler/test/beam_ssa_SUITE.erl @@ -23,7 +23,7 @@ init_per_group/2,end_per_group/2, calls/1,tuple_matching/1,recv/1,maps/1, cover_ssa_dead/1,combine_sw/1,share_opt/1, - beam_ssa_dead_crash/1]). + beam_ssa_dead_crash/1,stack_init/1]). suite() -> [{ct_hooks,[ts_install_cth]}]. @@ -39,7 +39,8 @@ groups() -> cover_ssa_dead, combine_sw, share_opt, - beam_ssa_dead_crash + beam_ssa_dead_crash, + stack_init ]}]. init_per_suite(Config) -> @@ -611,6 +612,30 @@ do_beam_ssa_dead_crash(A, B) -> end end. +stack_init(_Config) -> + 6 = stack_init(a, #{a => [1,2,3]}), + 0 = stack_init(missing, #{}), + ok. + +stack_init(Key, Map) -> + %% beam_ssa_codegen would wrongly assume that y(0) would always be + %% initialized by the `get_map_elements` instruction that follows, and + %% would set up the stack frame using an `allocate` instruction and + %% would not generate an `init` instruction to initialize y(0). + Res = case Map of + #{Key := Elements} -> + %% Elements will be assigned to y(0) if the key Key exists. + lists:foldl(fun(El, Acc) -> + Acc + El + end, 0, Elements); + #{} -> + %% y(0) will be left uninitialized when the key is not + %% present in the map. + 0 + end, + %% y(0) would be uninitialized here if the key was not present in the map + %% (if the second clause was executed). + id(Res). %% The identity function. id(I) -> I. |