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-rw-r--r--lib/compiler/src/v3_codegen.erl106
1 files changed, 74 insertions, 32 deletions
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index f531056591..4df1aadd0a 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -1089,6 +1089,23 @@ protected_cg(Ts, Rs, _Fail, I, Vdb, Bef, St0) ->
%% test_cg(TestName, Args, Fail, I, Vdb, Bef, St) -> {[Ainstr],Aft,St}.
%% Generate test instruction. Use explicit fail label here.
+test_cg(is_map, [A], Fail, I, Vdb, Bef, St) ->
+ %% We must avoid creating code like this:
+ %%
+ %% move x(0) y(0)
+ %% is_map Fail [x(0)]
+ %% make_fun => x(0) %% Overwrite x(0)
+ %% put_map_assoc y(0) ...
+ %%
+ %% The code is safe, but beam_validator does not understand that.
+ %% Extending beam_validator to handle such (rare) code as the
+ %% above would make it slower for all programs. Instead, change
+ %% the code generator to always prefer the Y register for is_map()
+ %% and put_map_assoc() instructions, ensuring that they use the
+ %% same register.
+ Arg = cg_reg_arg_prefer_y(A, Bef),
+ Aft = clear_dead(Bef, I, Vdb),
+ {[{test,is_map,{f,Fail},[Arg]}],Aft,St};
test_cg(Test, As, Fail, I, Vdb, Bef, St) ->
Args = cg_reg_args(As, Bef),
Aft = clear_dead(Bef, I, Vdb),
@@ -1155,19 +1172,15 @@ call_cg(Func, As, Rs, Le, Vdb, Bef, St0) ->
%% Inside a guard. The only allowed function call is to
%% erlang:error/1,2. We will generate the following code:
%%
- %% jump FailureLabel
%% move {atom,ok} DestReg
- %%
- %% The 'move' instruction will never be executed, but we
- %% generate it anyway in case the beam_validator is run
- %% on unoptimized code.
+ %% jump FailureLabel
{remote,{atom,erlang},{atom,error}} = Func, %Assertion.
[{var,DestVar}] = Rs,
Int0 = clear_dead(Bef, Le#l.i, Vdb),
Reg = put_reg(DestVar, Int0#sr.reg),
Int = Int0#sr{reg=Reg},
Dst = fetch_reg(DestVar, Reg),
- {[{jump,{f,Fail}},{move,{atom,ok},Dst}],
+ {[{move,{atom,ok},Dst},{jump,{f,Fail}}],
clear_dead(Int, Le#l.i, Vdb),St0};
#cg{} ->
%% Ordinary function call in a function body.
@@ -1538,14 +1551,12 @@ set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef, #cg{bfail=Bfail}=St) ->
%% Now generate the complete code for constructing the binary.
Code = cg_binary(PutCode, Target, Temp, Fail, MaxRegs, Le#l.a),
{Sis++Code,Aft,St};
-% Map single variable key
-set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, Le, Vdb, Bef,
- #cg{bfail=Bfail}=St) ->
- Fail = {f,Bfail},
- {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St),
+%% Map: single variable key.
+set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, Le, Vdb, Bef, St0) ->
+ {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0),
- SrcReg = cg_reg_arg(Map,Int0),
+ SrcReg = cg_reg_arg_prefer_y(Map, Int0),
Line = line(Le#l.a),
List = [cg_reg_arg(K,Int0),cg_reg_arg(V,Int0)],
@@ -1557,22 +1568,17 @@ set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, Le, Vdb, Bef,
Aft = Aft0#sr{reg=put_reg(R, Aft0#sr.reg)},
Target = fetch_reg(R, Aft#sr.reg),
- I = case Op of
- assoc -> put_map_assoc;
- exact -> put_map_exact
- end,
- {Sis++[Line]++[{I,Fail,SrcReg,Target,Live,{list,List}}],Aft,St};
+ {Is,St1} = set_cg_map(Line, Op, SrcReg, Target, Live, List, St0),
+ {Sis++Is,Aft,St1};
-% Map (possibly) multiple literal keys
-set_cg([{var,R}], {map,Op,Map,Es}, Le, Vdb, Bef,
- #cg{bfail=Bfail}=St) ->
+%% Map: (possibly) multiple literal keys.
+set_cg([{var,R}], {map,Op,Map,Es}, Le, Vdb, Bef, St0) ->
%% assert key literals
[] = [Var||{map_pair,{var,_}=Var,_} <- Es],
- Fail = {f,Bfail},
- {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St),
- SrcReg = cg_reg_arg(Map,Int0),
+ {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0),
+ SrcReg = cg_reg_arg_prefer_y(Map, Int0),
Line = line(Le#l.a),
%% fetch registers for values to be put into the map
@@ -1586,11 +1592,10 @@ set_cg([{var,R}], {map,Op,Map,Es}, Le, Vdb, Bef,
Aft = Aft0#sr{reg=put_reg(R, Aft0#sr.reg)},
Target = fetch_reg(R, Aft#sr.reg),
- I = case Op of
- assoc -> put_map_assoc;
- exact -> put_map_exact
- end,
- {Sis++[Line]++[{I,Fail,SrcReg,Target,Live,{list,List}}],Aft,St};
+ {Is,St1} = set_cg_map(Line, Op, SrcReg, Target, Live, List, St0),
+ {Sis++Is,Aft,St1};
+
+%% Everything else.
set_cg([{var,R}], Con, Le, Vdb, Bef, St) ->
%% Find a place for the return register first.
Int = Bef#sr{reg=put_reg(R, Bef#sr.reg)},
@@ -1603,6 +1608,34 @@ set_cg([{var,R}], Con, Le, Vdb, Bef, St) ->
end,
{Ais,clear_dead(Int, Le#l.i, Vdb),St}.
+
+set_cg_map(Line, Op0, SrcReg, Target, Live, List, St0) ->
+ Bfail = St0#cg.bfail,
+ Fail = {f,St0#cg.bfail},
+ Op = case Op0 of
+ assoc -> put_map_assoc;
+ exact -> put_map_exact
+ end,
+ {OkLbl,St1} = new_label(St0),
+ {BadLbl,St2} = new_label(St1),
+ Is = if
+ Bfail =:= 0 orelse Op =:= put_map_assoc ->
+ [Line,{Op,{f,0},SrcReg,Target,Live,{list,List}}];
+ true ->
+ %% Ensure that Target is always set, even if
+ %% the map update operation fails. That is necessary
+ %% because Target may be included in a test_heap
+ %% instruction.
+ [Line,
+ {Op,{f,BadLbl},SrcReg,Target,Live,{list,List}},
+ {jump,{f,OkLbl}},
+ {label,BadLbl},
+ {move,{atom,ok},Target},
+ {jump,Fail},
+ {label,OkLbl}]
+ end,
+ {Is,St2}.
+
%%%
%%% Code generation for constructing binaries.
%%%
@@ -1845,6 +1878,9 @@ cg_reg_args(As, Bef) -> [cg_reg_arg(A, Bef) || A <- As].
cg_reg_arg({var,V}, Bef) -> fetch_var(V, Bef);
cg_reg_arg(Literal, _) -> Literal.
+cg_reg_arg_prefer_y({var,V}, Bef) -> fetch_var_prefer_y(V, Bef);
+cg_reg_arg_prefer_y(Literal, _) -> Literal.
+
%% cg_setup_call([Arg], Bef, Cur, Vdb) -> {[Instr],Aft}.
%% Do the complete setup for a call/enter.
@@ -2086,6 +2122,12 @@ fetch_var(V, Sr) ->
error -> fetch_stack(V, Sr#sr.stk)
end.
+fetch_var_prefer_y(V, #sr{reg=Reg,stk=Stk}) ->
+ case find_stack(V, Stk) of
+ {ok,R} -> R;
+ error -> fetch_reg(V, Reg)
+ end.
+
load_vars(Vs, Regs) ->
foldl(fun ({var,V}, Rs) -> put_reg(V, Rs) end, Regs, Vs).
@@ -2159,11 +2201,11 @@ fetch_stack(Var, Stk) -> fetch_stack(Var, Stk, 0).
fetch_stack(V, [{V}|_], I) -> {yy,I};
fetch_stack(V, [_|Stk], I) -> fetch_stack(V, Stk, I+1).
-% find_stack(Var, Stk) -> find_stack(Var, Stk, 0).
+find_stack(Var, Stk) -> find_stack(Var, Stk, 0).
-% find_stack(V, [{V}|Stk], I) -> {ok,{yy,I}};
-% find_stack(V, [O|Stk], I) -> find_stack(V, Stk, I+1);
-% find_stack(V, [], I) -> error.
+find_stack(V, [{V}|_], I) -> {ok,{yy,I}};
+find_stack(V, [_|Stk], I) -> find_stack(V, Stk, I+1);
+find_stack(_, [], _) -> error.
on_stack(V, Stk) -> keymember(V, 1, Stk).
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 00:02:57 +0000