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-rw-r--r--lib/compiler/src/beam_ssa_codegen.erl186
1 files changed, 138 insertions, 48 deletions
diff --git a/lib/compiler/src/beam_ssa_codegen.erl b/lib/compiler/src/beam_ssa_codegen.erl
index c2d5035b19..ff880c6296 100644
--- a/lib/compiler/src/beam_ssa_codegen.erl
+++ b/lib/compiler/src/beam_ssa_codegen.erl
@@ -28,7 +28,7 @@
-include("beam_ssa.hrl").
--import(lists, [foldl/3,keymember/3,keysort/2,last/1,map/2,mapfoldl/3,
+-import(lists, [foldl/3,keymember/3,keysort/2,map/2,mapfoldl/3,
reverse/1,reverse/2,sort/1,splitwith/2,takewhile/2]).
-record(cg, {lcount=1 :: beam_label(), %Label counter
@@ -37,7 +37,8 @@
used_labels=gb_sets:empty() :: gb_sets:set(ssa_label()),
regs=#{} :: #{beam_ssa:var_name()=>ssa_register()},
ultimate_fail=1 :: beam_label(),
- catches=gb_sets:empty() :: gb_sets:set(ssa_label())
+ catches=gb_sets:empty() :: gb_sets:set(ssa_label()),
+ fc_label=1 :: beam_label()
}).
-spec module(beam_ssa:b_module(), [compile:option()]) ->
@@ -114,17 +115,17 @@ functions(Forms, AtomMod) ->
function(#b_function{anno=Anno,bs=Blocks}, AtomMod, St0) ->
#{func_info:={_,Name,Arity}} = Anno,
try
- assert_badarg_block(Blocks), %Assertion.
+ assert_exception_block(Blocks), %Assertion.
Regs = maps:get(registers, Anno),
St1 = St0#cg{labels=#{},used_labels=gb_sets:empty(),
regs=Regs},
{Fi,St2} = new_label(St1), %FuncInfo label
{Entry,St3} = local_func_label(Name, Arity, St2),
{Ult,St4} = new_label(St3), %Ultimate failure
- Labels = (St4#cg.labels)#{0=>Entry,?BADARG_BLOCK=>0},
+ Labels = (St4#cg.labels)#{0=>Entry,?EXCEPTION_BLOCK=>0},
St5 = St4#cg{labels=Labels,used_labels=gb_sets:singleton(Entry),
ultimate_fail=Ult},
- {Body,St} = cg_fun(Blocks, St5),
+ {Body,St} = cg_fun(Blocks, St5#cg{fc_label=Fi}),
Asm = [{label,Fi},line(Anno),
{func_info,AtomMod,{atom,Name},Arity}] ++
add_parameter_annos(Body, Anno) ++
@@ -137,10 +138,10 @@ function(#b_function{anno=Anno,bs=Blocks}, AtomMod, St0) ->
erlang:raise(Class, Error, Stack)
end.
-assert_badarg_block(Blocks) ->
- %% Assertion: ?BADARG_BLOCK must be the call erlang:error(badarg).
+assert_exception_block(Blocks) ->
+ %% Assertion: ?EXCEPTION_BLOCK must be a call erlang:error(badarg).
case Blocks of
- #{?BADARG_BLOCK:=Blk} ->
+ #{?EXCEPTION_BLOCK:=Blk} ->
#b_blk{is=[#b_set{op=call,dst=Ret,
args=[#b_remote{mod=#b_literal{val=erlang},
name=#b_literal{val=error}},
@@ -148,7 +149,7 @@ assert_badarg_block(Blocks) ->
last=#b_ret{arg=Ret}} = Blk,
ok;
#{} ->
- %% ?BADARG_BLOCK has been removed because it was never used.
+ %% ?EXCEPTION_BLOCK has been removed because it was never used.
ok
end.
@@ -384,6 +385,7 @@ classify_heap_need(is_tagged_tuple) -> neutral;
classify_heap_need(kill_try_tag) -> gc;
classify_heap_need(landingpad) -> gc;
classify_heap_need(make_fun) -> gc;
+classify_heap_need(match_fail) -> gc;
classify_heap_need(new_try_tag) -> gc;
classify_heap_need(peek_message) -> gc;
classify_heap_need(put_map) -> gc;
@@ -629,7 +631,7 @@ liveness_get(S, LiveMap) ->
end.
liveness_successors(Terminator) ->
- successors(Terminator) -- [?BADARG_BLOCK].
+ successors(Terminator) -- [?EXCEPTION_BLOCK].
liveness_is([#cg_alloc{}=I0|Is], Regs, Live, Acc) ->
I = I0#cg_alloc{live=num_live(Live, Regs)},
@@ -764,9 +766,8 @@ defined(Linear, #cg{regs=Regs}) ->
def([{L,#cg_blk{is=Is0,last=Last}=Blk0}|Bs], DefMap0, Regs) ->
Def0 = def_get(L, DefMap0),
- {Is,Def} = def_is(Is0, Regs, Def0, []),
- Successors = successors(Last),
- DefMap = def_successors(Successors, Def, DefMap0),
+ {Is,Def,MaybeDef} = def_is(Is0, Regs, Def0, []),
+ DefMap = def_successors(Last, Def, MaybeDef, DefMap0),
Blk = Blk0#cg_blk{is=Is},
[{L,Blk}|def(Bs, DefMap, Regs)];
def([], _, _) -> [].
@@ -780,6 +781,11 @@ def_get(L, DefMap) ->
def_is([#cg_alloc{anno=Anno0}=I0|Is], Regs, Def, Acc) ->
I = I0#cg_alloc{anno=Anno0#{def_yregs=>Def}},
def_is(Is, Regs, Def, [I|Acc]);
+def_is([#cg_set{op=succeeded,args=[Var]}=I], Regs, Def, Acc) ->
+ %% Var will only be defined on the success branch of the `br`
+ %% for this block.
+ MaybeDef = def_add_yreg(Var, [], Regs),
+ {reverse(Acc, [I]),Def,MaybeDef};
def_is([#cg_set{op=kill_try_tag,args=[#b_var{}=Tag]}=I|Is], Regs, Def0, Acc) ->
Def = ordsets:del_element(Tag, Def0),
def_is(Is, Regs, Def, [I|Acc]);
@@ -822,7 +828,7 @@ def_is([#cg_set{anno=Anno0,dst=Dst}=I0|Is], Regs, Def0, Acc) ->
Def = def_add_yreg(Dst, Def0, Regs),
def_is(Is, Regs, Def, [I|Acc]);
def_is([], _, Def, Acc) ->
- {reverse(Acc),Def}.
+ {reverse(Acc),Def,[]}.
def_add_yreg(Dst, Def, Regs) ->
case is_yreg(Dst, Regs) of
@@ -830,6 +836,12 @@ def_add_yreg(Dst, Def, Regs) ->
false -> Def
end.
+def_successors(#cg_br{bool=#b_var{},succ=Succ,fail=Fail}, Def, MaybeDef, DefMap0) ->
+ DefMap = def_successors([Fail], ordsets:subtract(Def, MaybeDef), DefMap0),
+ def_successors([Succ], Def, DefMap);
+def_successors(Last, Def, [], DefMap) ->
+ def_successors(successors(Last), Def, DefMap).
+
def_successors([S|Ss], Def0, DefMap) ->
case DefMap of
#{S:=Def1} ->
@@ -963,6 +975,12 @@ cg_block(Is0, Last, Next, St0) ->
case Last of
#cg_br{succ=Next,fail=Next} ->
cg_block(Is0, none, St0);
+ #cg_br{succ=Same,fail=Same} when Same =:= ?EXCEPTION_BLOCK ->
+ %% An expression in this block *always* throws an exception, so we
+ %% terminate it with an 'if_end' to make sure the validator knows
+ %% that the following instructions won't actually be reached.
+ {Is,St} = cg_block(Is0, none, St0),
+ {Is++[if_end],St};
#cg_br{succ=Same,fail=Same} ->
{Fail,St1} = use_block_label(Same, St0),
{Is,St} = cg_block(Is0, none, St1),
@@ -1016,6 +1034,14 @@ bif_fail({catch_tag,_}) -> {f,0}.
next_block([]) -> none;
next_block([{Next,_}|_]) -> Next.
+%% Certain instructions (such as get_map_element or is_nonempty_list)
+%% are only used in guards and **must** have a non-zero label;
+%% otherwise, the loader will refuse to load the
+%% module. ensure_label/2 replaces a zero label with the "ultimate
+%% failure" label to make the module loadable. The instruction that
+%% have had the zero label replaced is **not** supposed to ever fail
+%% and actually jump to the label.
+
ensure_label(Fail0, #cg{ultimate_fail=Lbl}) ->
case bif_fail(Fail0) of
{f,0} -> {f,Lbl};
@@ -1160,6 +1186,15 @@ cg_block([#cg_set{op=call}=I,
#cg_set{op=succeeded,dst=Bool}], {Bool,_Fail}, St) ->
%% A call in try/catch block.
cg_block([I], none, St);
+cg_block([#cg_set{op=match_fail}=I,
+ #cg_set{op=succeeded,dst=Bool}], {Bool,_Fail}, St) ->
+ %% A match_fail instruction in a try/catch block.
+ cg_block([I], none, St);
+cg_block([#cg_set{op=get_map_element,dst=Dst0,args=Args0},
+ #cg_set{op=succeeded,dst=Bool}], {Bool,Fail0}, St) ->
+ [Dst,Map,Key] = beam_args([Dst0|Args0], St),
+ Fail = ensure_label(Fail0, St),
+ {[{get_map_elements,Fail,Map,{list,[Key,Dst]}}],St};
cg_block([#cg_set{op=Op,dst=Dst0,args=Args0}=I,
#cg_set{op=succeeded,dst=Bool}], {Bool,Fail}, St) ->
[Dst|Args] = beam_args([Dst0|Args0], St),
@@ -1216,6 +1251,28 @@ cg_block([#cg_set{op=copy}|_]=T0, Context, St0) ->
no ->
{Is,St}
end;
+cg_block([#cg_set{op=match_fail,args=Args0,anno=Anno}], none, St) ->
+ Args = beam_args(Args0, St),
+ Is = cg_match_fail(Args, line(Anno), none),
+ {Is,St};
+cg_block([#cg_set{op=match_fail,args=Args0,anno=Anno}|T], Context, St0) ->
+ FcLabel = case Context of
+ {return,_,none} ->
+ %% There is no stack frame. If this is a function_clause
+ %% exception, it is safe to jump to the label of the
+ %% func_info instruction.
+ St0#cg.fc_label;
+ _ ->
+ %% This is most probably not a function_clause.
+ %% If this is a function_clause exception
+ %% (rare), it is not safe to jump to the
+ %% func_info label.
+ none
+ end,
+ Args = beam_args(Args0, St0),
+ Is0 = cg_match_fail(Args, line(Anno), FcLabel),
+ {Is1,St} = cg_block(T, Context, St0),
+ {Is0++Is1,St};
cg_block([#cg_set{op=Op,dst=Dst0,args=Args0}=Set], none, St) ->
[Dst|Args] = beam_args([Dst0|Args0], St),
Is = cg_instr(Op, Args, Dst, Set),
@@ -1247,8 +1304,7 @@ cg_copy(T0, St) ->
end, T0),
Moves0 = cg_copy_1(Copies, St),
Moves1 = [Move || {move,Src,Dst}=Move <- Moves0, Src =/= Dst],
- Scratch = {x,1022},
- Moves = order_moves(Moves1, Scratch),
+ Moves = order_moves(Moves1),
{Moves,T}.
cg_copy_1([#cg_set{dst=Dst0,args=Args}|T], St) ->
@@ -1489,6 +1545,42 @@ cg_call(#cg_set{anno=Anno,op=call,dst=Dst0,args=Args0},
Is = setup_args(Args++[Func], Anno, Context, St) ++ Line ++ Call,
{Is,St}.
+cg_match_fail([{atom,function_clause}|Args], Line, Fc) ->
+ case Fc of
+ none ->
+ %% There is a stack frame (probably because of inlining).
+ %% Jumping to the func_info label is not allowed by
+ %% beam_validator. Rewrite the instruction as a call to
+ %% erlang:error/2.
+ make_fc(Args, Line);
+ _ ->
+ setup_args(Args) ++ [{jump,{f,Fc}}]
+ end;
+cg_match_fail([{atom,Op}], Line, _Fc) ->
+ [Line,Op];
+cg_match_fail([{atom,Op},Val], Line, _Fc) ->
+ [Line,{Op,Val}].
+
+make_fc(Args, Line) ->
+ %% Recreate the original call to erlang:error/2.
+ Live = foldl(fun({x,X}, A) -> max(X+1, A);
+ (_, A) -> A
+ end, 0, Args),
+ TmpReg = {x,Live},
+ StkMoves = build_stk(reverse(Args), TmpReg, nil),
+ [{test_heap,2*length(Args),Live}|StkMoves] ++
+ [{move,{atom,function_clause},{x,0}},
+ Line,
+ {call_ext,2,{extfunc,erlang,error,2}}].
+
+build_stk([V], _TmpReg, Tail) ->
+ [{put_list,V,Tail,{x,1}}];
+build_stk([V|Vs], TmpReg, Tail) ->
+ I = {put_list,V,Tail,TmpReg},
+ [I|build_stk(Vs, TmpReg, TmpReg)];
+build_stk([], _TmpReg, nil) ->
+ [{move,nil,{x,1}}].
+
build_call(call_fun, Arity, _Func, none, Dst) ->
[{call_fun,Arity}|copy({x,0}, Dst)];
build_call(call_fun, Arity, _Func, {return,Dst,N}, Dst) when is_integer(N) ->
@@ -1527,15 +1619,15 @@ build_apply(Arity, {return,Val,N}, _Dst) when is_integer(N) ->
build_apply(Arity, none, Dst) ->
[{apply,Arity}|copy({x,0}, Dst)].
-cg_instr(put_map, [{atom,assoc},SrcMap|Ss], Dst, Set) ->
- Live = get_live(Set),
- [{put_map_assoc,{f,0},SrcMap,Dst,Live,{list,Ss}}];
cg_instr(bs_get_tail, [Src], Dst, Set) ->
Live = get_live(Set),
[{bs_get_tail,Src,Dst,Live}];
cg_instr(bs_get_position, [Ctx], Dst, Set) ->
Live = get_live(Set),
[{bs_get_position,Ctx,Dst,Live}];
+cg_instr(put_map, [{atom,assoc},SrcMap|Ss], Dst, Set) ->
+ Live = get_live(Set),
+ [{put_map_assoc,{f,0},SrcMap,Dst,Live,{list,Ss}}];
cg_instr(Op, Args, Dst, _Set) ->
cg_instr(Op, Args, Dst).
@@ -1606,8 +1698,6 @@ cg_test({float,Op0}, Fail, Args, Dst, #cg_set{anno=Anno}) ->
'/' -> fdiv
end,
[line(Anno),{bif,Op,Fail,Args,Dst}];
-cg_test(get_map_element, Fail, [Map,Key], Dst, _I) ->
- [{get_map_elements,Fail,Map,{list,[Key,Dst]}}];
cg_test(peek_message, Fail, [], Dst, _I) ->
[{loop_rec,Fail,{x,0}}|copy({x,0}, Dst)];
cg_test(put_map, Fail, [{atom,exact},SrcMap|Ss], Dst, Set) ->
@@ -1707,7 +1797,7 @@ cg_catch(Agg, T0, Context, St0) ->
cg_try(Agg, Tag, T0, Context, St0) ->
{Moves0,T1} = cg_extract(T0, Agg, St0),
- Moves = order_moves(Moves0, {x,3}),
+ Moves = order_moves(Moves0),
[#cg_set{op=kill_try_tag}|T2] = T1,
{T,St} = cg_block(T2, Context, St0),
{[{try_case,Tag}|Moves++T],St}.
@@ -1759,7 +1849,7 @@ linearize(Blocks) ->
Linear = beam_ssa:linearize(Blocks),
linearize_1(Linear, Blocks).
-linearize_1([{?BADARG_BLOCK,_}|Ls], Blocks) ->
+linearize_1([{?EXCEPTION_BLOCK,_}|Ls], Blocks) ->
linearize_1(Ls, Blocks);
linearize_1([{L,Block0}|Ls], Blocks) ->
Block = translate_block(L, Block0, Blocks),
@@ -1863,8 +1953,7 @@ setup_args([]) ->
[];
setup_args([_|_]=Args) ->
Moves = gen_moves(Args, 0, []),
- Scratch = {x,1+last(sort([length(Args)-1|[X || {x,X} <- Args]]))},
- order_moves(Moves, Scratch).
+ order_moves(Moves).
%% kill_yregs(Anno, #cg{}) -> [{kill,{y,Y}}].
%% Kill Y registers that will not be used again.
@@ -1884,47 +1973,48 @@ gen_moves([A|As], I, Acc) ->
gen_moves([], _, Acc) ->
keysort(3, Acc).
-%% order_moves([Move], ScratchReg) -> [Move]
+%% order_moves([Move]) -> [Move]
%% Orders move instruction so that source registers are not
%% destroyed before they are used. If there are cycles
%% (such as {move,{x,0},{x,1}}, {move,{x,1},{x,1}}),
-%% the scratch register is used to break up the cycle.
-%% If possible, the first move of the input list is placed
+%% swap instructions will be used to break up the cycle.
+%%
+%% If possible, the first move of the input list is placed
%% last in the result list (to make the move to {x,0} occur
%% just before the call to allow the Beam loader to coalesce
%% the instructions).
-order_moves(Ms, Scr) -> order_moves(Ms, Scr, []).
+order_moves(Ms) -> order_moves(Ms, []).
-order_moves([{move,_,_}=M|Ms0], ScrReg, Acc0) ->
- {Chain,Ms} = collect_chain(Ms0, [M], ScrReg),
+order_moves([{move,_,_}=M|Ms0], Acc0) ->
+ {Chain,Ms} = collect_chain(Ms0, [M]),
Acc = reverse(Chain, Acc0),
- order_moves(Ms, ScrReg, Acc);
-order_moves([], _, Acc) -> Acc.
+ order_moves(Ms, Acc);
+order_moves([], Acc) -> Acc.
-collect_chain(Ms, Path, ScrReg) ->
- collect_chain(Ms, Path, [], ScrReg).
+collect_chain(Ms, Path) ->
+ collect_chain(Ms, Path, []).
-collect_chain([{move,Src,Same}=M|Ms0], [{move,Same,_}|_]=Path, Others, ScrReg) ->
+collect_chain([{move,Src,Same}=M|Ms0], [{move,Same,_}|_]=Path, Others) ->
case keymember(Src, 3, Path) of
false ->
- collect_chain(reverse(Others, Ms0), [M|Path], [], ScrReg);
+ collect_chain(reverse(Others, Ms0), [M|Path], []);
true ->
- %% There is a cycle, which we must break up.
- {break_up_cycle(M, Path, ScrReg),reverse(Others, Ms0)}
+ %% There is a cycle.
+ {break_up_cycle(M, Path),reverse(Others, Ms0)}
end;
-collect_chain([M|Ms], Path, Others, ScrReg) ->
- collect_chain(Ms, Path, [M|Others], ScrReg);
-collect_chain([], Path, Others, _) ->
+collect_chain([M|Ms], Path, Others) ->
+ collect_chain(Ms, Path, [M|Others]);
+collect_chain([], Path, Others) ->
{Path,Others}.
-break_up_cycle({move,Src,_}=M, Path, ScrReg) ->
- [{move,ScrReg,Src},M|break_up_cycle1(Src, Path, ScrReg)].
+break_up_cycle({move,Src,_Dst}=M, Path) ->
+ break_up_cycle_1(Src, [M|Path], []).
-break_up_cycle1(Dst, [{move,Src,Dst}|Path], ScrReg) ->
- [{move,Src,ScrReg}|Path];
-break_up_cycle1(Dst, [M|Path], LastMove) ->
- [M|break_up_cycle1(Dst, Path, LastMove)].
+break_up_cycle_1(Dst, [{move,_Src,Dst}|Path], Acc) ->
+ reverse(Acc, Path);
+break_up_cycle_1(Dst, [{move,S,D}|Path], Acc) ->
+ break_up_cycle_1(Dst, Path, [{swap,S,D}|Acc]).
%%%
%%% General utility functions.
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-25 20:38:59 +0000