diff options
Diffstat (limited to 'lib/compiler/src')
| -rw-r--r-- | lib/compiler/src/beam_validator.erl | 62 |
1 files changed, 31 insertions, 31 deletions
diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl index afede2b54d..abc3aa3875 100644 --- a/lib/compiler/src/beam_validator.erl +++ b/lib/compiler/src/beam_validator.erl @@ -1531,21 +1531,8 @@ validate_select_val(Fail, [Val,{f,L}|T], Src, Vst0) -> update_ne_types(Src, Val, FailVst) end), validate_select_val(Fail, T, Src, Vst); -validate_select_val(Fail, [], Src, Vst) -> +validate_select_val(Fail, [], _Src, Vst) -> branch(Fail, Vst, - fun(FailVst) -> - FailType = get_term_type(Src, FailVst), - case beam_types:get_singleton_value(FailType) of - {ok, Value} -> - %% This is the only possible value at the fail - %% label, so we can infer types as if we matched it - %% directly. - Lit = value_to_literal(Value), - update_eq_types(Src, Lit, FailVst); - error -> - FailVst - end - end, fun(SuccVst) -> %% The next instruction is never executed. kill_state(SuccVst) @@ -1595,27 +1582,23 @@ infer_types(CompareOp, LHS, RHS, #vst{current=#st{vs=Vs}}=Vst0) -> Vst0 end. -infer_types_1(#value{op={bif,'=:='},args=[LHS,RHS]}, Val, Op, Vst0) -> +infer_types_1(#value{op={bif,'=:='},args=[LHS,RHS]}, Val, Op, Vst) -> case Val of {atom, Bool} when Op =:= eq_exact, Bool; Op =:= ne_exact, not Bool -> - Vst = infer_types(eq_exact, RHS, LHS, Vst0), infer_types(eq_exact, LHS, RHS, Vst); {atom, Bool} when Op =:= ne_exact, Bool; Op =:= eq_exact, not Bool -> - Vst = infer_types(ne_exact, RHS, LHS, Vst0), infer_types(ne_exact, LHS, RHS, Vst); _ -> - Vst0 + Vst end; -infer_types_1(#value{op={bif,'=/='},args=[LHS,RHS]}, Val, Op, Vst0) -> +infer_types_1(#value{op={bif,'=/='},args=[LHS,RHS]}, Val, Op, Vst) -> case Val of {atom, Bool} when Op =:= ne_exact, Bool; Op =:= eq_exact, not Bool -> - Vst = infer_types(ne_exact, RHS, LHS, Vst0), infer_types(ne_exact, LHS, RHS, Vst); {atom, Bool} when Op =:= eq_exact, Bool; Op =:= ne_exact, not Bool -> - Vst = infer_types(eq_exact, RHS, LHS, Vst0), infer_types(eq_exact, LHS, RHS, Vst); _ -> - Vst0 + Vst end; infer_types_1(#value{op={bif,element},args=[{integer,Index},Tuple]}, Val, Op, Vst) when Index >= 1 -> @@ -1797,17 +1780,21 @@ update_type(Merge, With, Literal, Vst) -> end. update_eq_types(LHS, RHS, Vst0) -> - Vst1 = infer_types(eq_exact, LHS, RHS, Vst0), + LType = get_term_type(LHS, Vst0), + RType = get_term_type(RHS, Vst0), - T1 = get_term_type(LHS, Vst1), - T2 = get_term_type(RHS, Vst1), + Vst1 = update_type(fun meet/2, RType, LHS, Vst0), + Vst = update_type(fun meet/2, LType, RHS, Vst1), - Vst = update_type(fun meet/2, T2, LHS, Vst1), - update_type(fun meet/2, T1, RHS, Vst). + infer_types(eq_exact, LHS, RHS, Vst). update_ne_types(LHS, RHS, Vst0) -> - Vst = infer_types(ne_exact, LHS, RHS, Vst0), + Vst1 = update_ne_types_1(LHS, RHS, Vst0), + Vst = update_ne_types_1(RHS, LHS, Vst1), + + infer_types(ne_exact, LHS, RHS, Vst). +update_ne_types_1(LHS, RHS, Vst0) -> %% While updating types on equality is fairly straightforward, inequality %% is a bit trickier since all we know is that the *value* of LHS differs %% from RHS, so we can't blindly subtract their types. @@ -1817,10 +1804,23 @@ update_ne_types(LHS, RHS, Vst0) -> %% #t_integer{} we would erroneously infer that the new type is float. %% %% Therefore, we only subtract when we know that RHS has a specific value. - RType = get_term_type(RHS, Vst), + RType = get_term_type(RHS, Vst0), case beam_types:is_singleton_type(RType) of - true -> update_type(fun subtract/2, RType, LHS, Vst); - false -> Vst + true -> + Vst = update_type(fun subtract/2, RType, LHS, Vst0), + + %% If LHS has a specific value after subtraction we can infer types + %% as if we've made an exact match, which is much stronger than + %% ne_exact. + LType = get_term_type(LHS, Vst), + case beam_types:get_singleton_value(LType) of + {ok, Value} -> + infer_types(eq_exact, LHS, value_to_literal(Value), Vst); + error -> + Vst + end; + false -> + Vst0 end. %% Helper functions for the above. |