diff options
Diffstat (limited to 'lib/compiler/src/beam_dead.erl')
| -rw-r--r-- | lib/compiler/src/beam_dead.erl | 72 |
1 files changed, 48 insertions, 24 deletions
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index d379fdc4eb..dbbaae05eb 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -56,8 +56,7 @@ function({function,Name,Arity,CLabel,Is0}, Lc0) -> Is = move_move_into_block(Is3, []), {{function,Name,Arity,CLabel,Is},Lc} catch - Class:Error -> - Stack = erlang:get_stacktrace(), + Class:Error:Stack -> io:fwrite("Function: ~w/~w\n", [Name,Arity]), erlang:raise(Class, Error, Stack) end. @@ -272,7 +271,8 @@ backward([{jump,{f,To0}},{move,Src,Reg}=Move|Is], D, Acc) -> end; backward([{jump,{f,To}}=J|[{bif,Op,{f,BifFail},Ops,Reg}|Is]=Is0], D, Acc) -> try replace_comp_op(To, Reg, Op, Ops, D) of - I -> backward(Is, D, I++Acc) + {Test,Jump} -> + backward([Jump,Test|Is], D, Acc) catch throw:not_possible -> case To =:= BifFail of @@ -294,24 +294,25 @@ backward([{jump,{f,To}}=J|[{gc_bif,_,{f,To},_,_,_Dst}|Is]], D, Acc) -> %% register is initialized, and it is therefore no need to test %% for liveness of the destination register at label To. backward([J|Is], D, Acc); -backward([{test,bs_start_match2,F,Live,[R,_]=Args,Ctxt}|Is], D, - [{test,bs_match_string,F,[Ctxt,Bs]}, - {test,bs_test_tail2,F,[Ctxt,0]}|Acc0]=Acc) -> +backward([{test,bs_start_match2,F,Live,[Src,_]=Args,Ctxt}|Is], D, Acc0) -> {f,To0} = F, - case beam_utils:is_killed(Ctxt, Acc0, D) of - true -> - To = shortcut_bs_context_to_binary(To0, R, D), - Eq = {test,is_eq_exact,{f,To},[R,{literal,Bs}]}, - backward(Is, D, [Eq|Acc0]); - false -> - To = shortcut_bs_start_match(To0, R, D), - I = {test,bs_start_match2,{f,To},Live,Args,Ctxt}, - backward(Is, D, [I|Acc]) + case test_bs_literal(F, Ctxt, D, Acc0) of + {none,Acc} -> + %% Ctxt killed immediately after bs_start_match2. + To = shortcut_bs_context_to_binary(To0, Src, D), + I = {test,is_bitstr,{f,To},[Src]}, + backward(Is, D, [I|Acc]); + {Literal,Acc} -> + %% Ctxt killed after matching a literal. + To = shortcut_bs_context_to_binary(To0, Src, D), + Eq = {test,is_eq_exact,{f,To},[Src,{literal,Literal}]}, + backward(Is, D, [Eq|Acc]); + not_killed -> + %% Ctxt not killed. Not much to do. + To = shortcut_bs_start_match(To0, Src, D), + I = {test,bs_start_match2,{f,To},Live,Args,Ctxt}, + backward(Is, D, [I|Acc0]) end; -backward([{test,bs_start_match2,{f,To0},Live,[Src|_]=Info,Dst}|Is], D, Acc) -> - To = shortcut_bs_start_match(To0, Src, D), - I = {test,bs_start_match2,{f,To},Live,Info,Dst}, - backward(Is, D, [I|Acc]); backward([{test,Op,{f,To0},Ops0}|Is], D, Acc) -> To1 = shortcut_bs_test(To0, Is, D), To2 = shortcut_label(To1, D), @@ -446,7 +447,7 @@ prune_redundant([], _) -> []. replace_comp_op(To, Reg, Op, Ops, D) -> False = comp_op_find_shortcut(To, Reg, {atom,false}, D), True = comp_op_find_shortcut(To, Reg, {atom,true}, D), - [bif_to_test(Op, Ops, False),{jump,{f,True}}]. + {bif_to_test(Op, Ops, False),{jump,{f,True}}}. comp_op_find_shortcut(To0, Reg, Val, D) -> case shortcut_select_label(To0, Reg, Val, D) of @@ -483,15 +484,22 @@ not_possible() -> throw(not_possible). %% F1: is_eq_exact F2 Reg Lit2 F1: is_eq_exact F2 Reg Lit2 %% L2: .... L2: %% -combine_eqs(To, [Reg,{Type,_}=Lit1]=Ops, D, [{label,L1}|_]) - when Type =:= atom; Type =:= integer -> +combine_eqs(To, [Reg,{Type,_}=Lit1]=Ops, D, Acc) + when Type =:= atom; Type =:= integer -> + Next = case Acc of + [{label,Lbl}|_] -> Lbl; + [{jump,{f,Lbl}}|_] -> Lbl + end, case beam_utils:code_at(To, D) of [{test,is_eq_exact,{f,F2},[Reg,{Type,_}=Lit2]}, {label,L2}|_] when Lit1 =/= Lit2 -> - {select,select_val,Reg,{f,F2},[Lit1,{f,L1},Lit2,{f,L2}]}; + {select,select_val,Reg,{f,F2},[Lit1,{f,Next},Lit2,{f,L2}]}; + [{test,is_eq_exact,{f,F2},[Reg,{Type,_}=Lit2]}, + {jump,{f,L2}}|_] when Lit1 =/= Lit2 -> + {select,select_val,Reg,{f,F2},[Lit1,{f,Next},Lit2,{f,L2}]}; [{select,select_val,Reg,{f,F2},[{Type,_}|_]=List0}|_] -> List = remove_from_list(Lit1, List0), - {select,select_val,Reg,{f,F2},[Lit1,{f,L1}|List]}; + {select,select_val,Reg,{f,F2},[Lit1,{f,Next}|List]}; _Is -> {test,is_eq_exact,{f,To},Ops} end; @@ -504,6 +512,22 @@ remove_from_list(Lit, [Val,{f,_}=Fail|T]) -> [Val,Fail|remove_from_list(Lit, T)]; remove_from_list(_, []) -> []. + +test_bs_literal(F, Ctxt, D, + [{test,bs_match_string,F,[Ctxt,Bs]}, + {test,bs_test_tail2,F,[Ctxt,0]}|Acc]) -> + test_bs_literal_1(Ctxt, Acc, D, Bs); +test_bs_literal(F, Ctxt, D, [{test,bs_test_tail2,F,[Ctxt,0]}|Acc]) -> + test_bs_literal_1(Ctxt, Acc, D, <<>>); +test_bs_literal(_, Ctxt, D, Acc) -> + test_bs_literal_1(Ctxt, Acc, D, none). + +test_bs_literal_1(Ctxt, Is, D, Literal) -> + case beam_utils:is_killed(Ctxt, Is, D) of + true -> {Literal,Is}; + false -> not_killed + end. + %% shortcut_bs_test(TargetLabel, ReversedInstructions, D) -> TargetLabel' %% Try to shortcut the failure label for bit syntax matching. |