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-rw-r--r--lib/compiler/src/beam_ssa_type.erl187
1 files changed, 135 insertions, 52 deletions
diff --git a/lib/compiler/src/beam_ssa_type.erl b/lib/compiler/src/beam_ssa_type.erl
index 3b5d25efce..5fbb679c6f 100644
--- a/lib/compiler/src/beam_ssa_type.erl
+++ b/lib/compiler/src/beam_ssa_type.erl
@@ -23,7 +23,8 @@
-include("beam_ssa_opt.hrl").
-import(lists, [all/2,any/2,droplast/1,foldl/3,last/1,member/2,
- partition/2,reverse/1,reverse/2,seq/2,sort/1]).
+ keyfind/3,partition/2,reverse/1,reverse/2,
+ seq/2,sort/1]).
-define(UNICODE_INT, #t_integer{elements={0,16#10FFFF}}).
@@ -260,22 +261,33 @@ opt_is([#b_set{op=phi,dst=Dst,args=Args0}=I0|Is],
opt_is(Is, Ts, Ds, Fdb, D, Sub0, [I|Acc])
end;
opt_is([#b_set{op=call,args=Args0,dst=Dst}=I0|Is],
- Ts0, Ds0, Fdb0, D, Sub, Acc) ->
- Args = simplify_args(Args0, Sub, Ts0),
+ Ts0, Ds0, Fdb0, D, Sub0, Acc) ->
+ Args = simplify_args(Args0, Sub0, Ts0),
I1 = beam_ssa:normalize(I0#b_set{args=Args}),
- {Ts,Ds,Fdb,I} = opt_call(I1, D, Ts0, Ds0, Fdb0),
- case {map_get(Dst, Ts),Is} of
- {none,[#b_set{op=succeeded}]} ->
+ {Ts1,Ds,Fdb,I2} = opt_call(I1, D, Ts0, Ds0, Fdb0),
+ case {map_get(Dst, Ts1),Is} of
+ {_,[#b_set{op=succeeded}]} ->
%% This call instruction is inside a try/catch
%% block. Don't attempt to optimize it.
- opt_is(Is, Ts, Ds, Fdb, D, Sub, [I|Acc]);
+ opt_is(Is, Ts1, Ds, Fdb, D, Sub0, [I2|Acc]);
{none,_} ->
%% This call never returns. The rest of the
%% instructions will not be executed.
Ret = #b_ret{arg=Dst},
- {no_return,Ret,reverse(Acc, [I]),Ds,Fdb,Sub};
- _ ->
- opt_is(Is, Ts, Ds, Fdb, D, Sub, [I|Acc])
+ {no_return,Ret,reverse(Acc, [I2]),Ds,Fdb,Sub0};
+ {_,_} ->
+ case simplify_call(I2) of
+ #b_set{}=I ->
+ opt_is(Is, Ts1, Ds, Fdb, D, Sub0, [I|Acc]);
+ #b_literal{}=Lit ->
+ Sub = Sub0#{Dst=>Lit},
+ Ts = maps:remove(Dst, Ts1),
+ opt_is(Is, Ts, Ds0, Fdb, D, Sub, Acc);
+ #b_var{}=Var ->
+ Ts = maps:remove(Dst, Ts1),
+ Sub = Sub0#{Dst=>Var},
+ opt_is(Is, Ts, Ds0, Fdb, D, Sub, Acc)
+ end
end;
opt_is([#b_set{op=succeeded,args=[Arg],dst=Dst}=I],
Ts0, Ds0, Fdb, D, Sub0, Acc) ->
@@ -328,6 +340,48 @@ opt_is([#b_set{args=Args0,dst=Dst}=I0|Is],
opt_is([], Ts, Ds, Fdb, _D, Sub, Acc) ->
{reverse(Acc), Ts, Ds, Fdb, Sub}.
+simplify_call(#b_set{op=call,args=[#b_remote{}=Rem|Args]}=I) ->
+ case Rem of
+ #b_remote{mod=#b_literal{val=Mod},
+ name=#b_literal{val=Name}} ->
+ case erl_bifs:is_pure(Mod, Name, length(Args)) of
+ true ->
+ simplify_remote_call(Mod, Name, Args, I);
+ false ->
+ I
+ end;
+ #b_remote{} ->
+ I
+ end;
+simplify_call(I) -> I.
+
+%% Simplify a remote call to a pure BIF.
+simplify_remote_call(erlang, '++', [#b_literal{val=[]},Tl], _I) ->
+ Tl;
+simplify_remote_call(Mod, Name, Args0, I) ->
+ case make_literal_list(Args0) of
+ none ->
+ I;
+ Args ->
+ %% The arguments are literals. Try to evaluate the BIF.
+ try apply(Mod, Name, Args) of
+ Val ->
+ case cerl:is_literal_term(Val) of
+ true ->
+ #b_literal{val=Val};
+ false ->
+ %% The value can't be expressed as a literal
+ %% (e.g. a pid).
+ I
+ end
+ catch
+ _:_ ->
+ %% Failed. Don't bother trying to optimize
+ %% the call.
+ I
+ end
+ end.
+
opt_call(#b_set{dst=Dst,args=[#b_local{}=Callee|Args]}=I0, D, Ts0, Ds0, Fdb0) ->
{Ts, Ds, I} = opt_local_call(I0, Ts0, Ds0, Fdb0),
case Fdb0 of
@@ -452,10 +506,19 @@ simplify(#b_set{op={bif,'=='},args=Args}=I, Ts) ->
end;
simplify(#b_set{op={bif,'=:='},args=[Same,Same]}, _Ts) ->
#b_literal{val=true};
-simplify(#b_set{op={bif,'=:='},args=Args}=I, Ts) ->
- case meet(get_types(Args, Ts)) of
- none -> #b_literal{val=false};
- _ -> eval_bif(I, Ts)
+simplify(#b_set{op={bif,'=:='},args=[A1,_A2]=Args}=I, Ts) ->
+ [T1,T2] = get_types(Args, Ts),
+ case meet(T1, T2) of
+ none ->
+ #b_literal{val=false};
+ _ ->
+ case {t_is_boolean(T1),T2} of
+ {true,#t_atom{elements=[true]}} ->
+ %% Bool =:= true ==> Bool
+ A1;
+ {_,_} ->
+ eval_bif(I, Ts)
+ end
end;
simplify(#b_set{op={bif,Op},args=Args}=I, Ts) ->
Types = get_types(Args, Ts),
@@ -598,41 +661,49 @@ anno_float_arg(_) -> convert.
opt_terminator(#b_br{bool=#b_literal{}}=Br, _Ts, _Ds) ->
beam_ssa:normalize(Br);
-opt_terminator(#b_br{bool=#b_var{}=V}=Br, Ts, Ds) ->
- #{V:=Set} = Ds,
- case Set of
- #b_set{op={bif,'=:='},args=[Bool,#b_literal{val=true}]} ->
- case t_is_boolean(get_type(Bool, Ts)) of
- true ->
- %% Bool =:= true ==> Bool
- simplify_not(Br#b_br{bool=Bool}, Ts, Ds);
- false ->
- Br
- end;
- #b_set{} ->
- simplify_not(Br, Ts, Ds)
- end;
+opt_terminator(#b_br{bool=#b_var{}}=Br, Ts, Ds) ->
+ simplify_not(Br, Ts, Ds);
opt_terminator(#b_switch{arg=#b_literal{}}=Sw, _Ts, _Ds) ->
beam_ssa:normalize(Sw);
-opt_terminator(#b_switch{arg=#b_var{}=V}=Sw0, Ts, Ds) ->
- Type = get_type(V, Ts),
+opt_terminator(#b_switch{arg=#b_var{}=V}=Sw, Ts, Ds) ->
+ case get_type(V, Ts) of
+ any ->
+ beam_ssa:normalize(Sw);
+ Type ->
+ beam_ssa:normalize(opt_switch(Sw, Type, Ts, Ds))
+ end;
+opt_terminator(#b_ret{}=Ret, _Ts, _Ds) -> Ret.
+
+
+opt_switch(#b_switch{fail=Fail,list=List0}=Sw0, Type, Ts, Ds) ->
+ List = prune_switch_list(List0, Fail, Type, Ts),
+ Sw1 = Sw0#b_switch{list=List},
case Type of
#t_integer{elements={_,_}=Range} ->
- simplify_switch_int(Sw0, Range);
- _ ->
+ simplify_switch_int(Sw1, Range);
+ #t_atom{elements=[_|_]} ->
case t_is_boolean(Type) of
true ->
- case simplify_switch_bool(Sw0, Ts, Ds) of
- #b_br{}=Br ->
- opt_terminator(Br, Ts, Ds);
- Sw ->
- beam_ssa:normalize(Sw)
- end;
+ #b_br{} = Br = simplify_switch_bool(Sw1, Ts, Ds),
+ opt_terminator(Br, Ts, Ds);
false ->
- beam_ssa:normalize(Sw0)
- end
+ simplify_switch_atom(Type, Sw1)
+ end;
+ _ ->
+ Sw1
+ end.
+
+prune_switch_list([{_,Fail}|T], Fail, Type, Ts) ->
+ prune_switch_list(T, Fail, Type, Ts);
+prune_switch_list([{Arg,_}=Pair|T], Fail, Type, Ts) ->
+ case meet(get_type(Arg, Ts), Type) of
+ none ->
+ %% Different types. This value can never match.
+ prune_switch_list(T, Fail, Type, Ts);
+ _ ->
+ [Pair|prune_switch_list(T, Fail, Type, Ts)]
end;
-opt_terminator(#b_ret{}=Ret, _Ts, _Ds) -> Ret.
+prune_switch_list([], _, _, _) -> [].
update_successors(#b_br{bool=#b_literal{val=true},succ=S}, Ts, D) ->
update_successor(S, Ts, D);
@@ -641,8 +712,8 @@ update_successors(#b_br{bool=#b_var{}=Bool,succ=Succ,fail=Fail}, Ts0, D0) ->
true ->
%% This variable is defined in this block and is only
%% referenced by this br terminator. Therefore, there is
- %% no need to include the type database passed on to the
- %% successors of this block.
+ %% no need to include it in the type database passed on to
+ %% the successors of this block.
Ts = maps:remove(Bool, Ts0),
{SuccTs,FailTs} = infer_types_br(Bool, Ts, D0),
D = update_successor(Fail, FailTs, D0),
@@ -1029,6 +1100,17 @@ bs_match_type(utf16, _) ->
bs_match_type(utf32, _) ->
?UNICODE_INT.
+simplify_switch_atom(#t_atom{elements=Atoms}, #b_switch{list=List0}=Sw) ->
+ case sort([A || {#b_literal{val=A},_} <- List0]) of
+ Atoms ->
+ %% All possible atoms are included in the list. The
+ %% failure label will never be used.
+ [{_,Fail}|List] = List0,
+ Sw#b_switch{fail=Fail,list=List};
+ _ ->
+ Sw
+ end.
+
simplify_switch_int(#b_switch{list=List0}=Sw, {Min,Max}) ->
List1 = sort(List0),
Vs = [V || {#b_literal{val=V},_} <- List1],
@@ -1073,14 +1155,14 @@ simplify_is_record(I, any, _Size, _Tag, _Ts) ->
simplify_is_record(_I, _Type, _Size, _Tag, _Ts) ->
#b_literal{val=false}.
-simplify_switch_bool(#b_switch{arg=B,list=List0}=Sw, Ts, Ds) ->
- List = sort(List0),
- case List of
- [{#b_literal{val=false},Fail},{#b_literal{val=true},Succ}] ->
- simplify_not(#b_br{bool=B,succ=Succ,fail=Fail}, Ts, Ds);
- [_|_] ->
- Sw
- end.
+simplify_switch_bool(#b_switch{arg=B,fail=Fail,list=List0}, Ts, Ds) ->
+ FalseVal = #b_literal{val=false},
+ TrueVal = #b_literal{val=true},
+ List1 = List0 ++ [{FalseVal,Fail},{TrueVal,Fail}],
+ {_,FalseLbl} = keyfind(FalseVal, 1, List1),
+ {_,TrueLbl} = keyfind(TrueVal, 1, List1),
+ Br = beam_ssa:normalize(#b_br{bool=B,succ=TrueLbl,fail=FalseLbl}),
+ simplify_not(Br, Ts, Ds).
simplify_not(#b_br{bool=#b_var{}=V,succ=Succ,fail=Fail}=Br0, Ts, Ds) ->
case Ds of
@@ -1094,7 +1176,8 @@ simplify_not(#b_br{bool=#b_var{}=V,succ=Succ,fail=Fail}=Br0, Ts, Ds) ->
end;
#{} ->
Br0
- end.
+ end;
+simplify_not(#b_br{bool=#b_literal{}}=Br, _Ts, _Ds) -> Br.
%%%
%%% Calculate the set of variables that are only used once in the