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-rw-r--r--lib/compiler/src/beam_type.erl23
1 files changed, 17 insertions, 6 deletions
diff --git a/lib/compiler/src/beam_type.erl b/lib/compiler/src/beam_type.erl
index 5076c5eb96..79f93d7548 100644
--- a/lib/compiler/src/beam_type.erl
+++ b/lib/compiler/src/beam_type.erl
@@ -513,12 +513,23 @@ update({call_ext,Ar,{extfunc,math,Math,Ar}}, Ts) ->
false -> tdb_kill_xregs(Ts)
end;
update({call_ext,3,{extfunc,erlang,setelement,3}}, Ts0) ->
- Op = case tdb_find({x,1}, Ts0) of
- error -> kill;
- Info -> Info
- end,
- Ts1 = tdb_kill_xregs(Ts0),
- tdb_update([{{x,0},Op}], Ts1);
+ Ts = tdb_kill_xregs(Ts0),
+ case tdb_find({x,1}, Ts0) of
+ {tuple,Sz,_}=T0 ->
+ T = case tdb_find({x,0}, Ts0) of
+ {integer,{I,I}} when I > 1 ->
+ %% First element is not changed. The result
+ %% will have the same type.
+ T0;
+ _ ->
+ %% Position is 1 or unknown. May change the
+ %% first element of the tuple.
+ {tuple,Sz,[]}
+ end,
+ tdb_update([{{x,0},T}], Ts);
+ _ ->
+ Ts
+ end;
update({call,_Arity,_Func}, Ts) -> tdb_kill_xregs(Ts);
update({call_ext,_Arity,_Func}, Ts) -> tdb_kill_xregs(Ts);
update({make_fun2,_,_,_,_}, Ts) -> tdb_kill_xregs(Ts);