diff options
Diffstat (limited to 'lib/compiler/src/beam_ssa_codegen.erl')
-rw-r--r-- | lib/compiler/src/beam_ssa_codegen.erl | 153 |
1 files changed, 111 insertions, 42 deletions
diff --git a/lib/compiler/src/beam_ssa_codegen.erl b/lib/compiler/src/beam_ssa_codegen.erl index 07f4c8b461..10c3419314 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)}, @@ -963,6 +965,12 @@ 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), @@ -1168,6 +1176,10 @@ 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), @@ -1229,6 +1241,28 @@ 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), @@ -1260,8 +1294,7 @@ 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) -> @@ -1502,6 +1535,42 @@ 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) -> @@ -1540,15 +1609,15 @@ 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). @@ -1718,7 +1787,7 @@ 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}. @@ -1770,7 +1839,7 @@ 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), @@ -1874,8 +1943,7 @@ 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. @@ -1895,47 +1963,48 @@ 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. |