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-rw-r--r--lib/compiler/src/beam_bs.erl280
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diff --git a/lib/compiler/src/beam_bs.erl b/lib/compiler/src/beam_bs.erl
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index 5f1b9ed488..0000000000
--- a/lib/compiler/src/beam_bs.erl
+++ /dev/null
@@ -1,280 +0,0 @@
-%%
-%% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 1999-2018. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%% http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%
-%% %CopyrightEnd%
-%%
-%% Purpose : Partitions assembly instructions into basic blocks and
-%% optimizes them.
-
--module(beam_bs).
-
--export([module/2]).
--import(lists, [mapfoldl/3,reverse/1]).
-
--spec module(beam_utils:module_code(), [compile:option()]) ->
- {'ok',beam_utils:module_code()}.
-
-module({Mod,Exp,Attr,Fs0,Lc0}, _Opt) ->
- {Fs,Lc} = mapfoldl(fun function/2, Lc0, Fs0),
- {ok,{Mod,Exp,Attr,Fs,Lc}}.
-
-function({function,Name,Arity,CLabel,Is0}, Lc0) ->
- try
- Is1 = bs_put_opt(Is0),
- {Is,Lc} = bsm_opt(Is1, Lc0),
- {{function,Name,Arity,CLabel,Is},Lc}
- catch
- Class:Error:Stack ->
- io:fwrite("Function: ~w/~w\n", [Name,Arity]),
- erlang:raise(Class, Error, Stack)
- end.
-
-%%%
-%%% Evaluation of constant bit fields.
-%%%
-
-bs_put_opt([{bs_put,_,_,_}=I|Is0]) ->
- {BsPuts0,Is} = collect_bs_puts(Is0, [I]),
- BsPuts = opt_bs_puts(BsPuts0),
- BsPuts ++ bs_put_opt(Is);
-bs_put_opt([I|Is]) ->
- [I|bs_put_opt(Is)];
-bs_put_opt([]) -> [].
-
-collect_bs_puts([{bs_put,_,_,_}=I|Is], Acc) ->
- collect_bs_puts(Is, [I|Acc]);
-collect_bs_puts([_|_]=Is, Acc) ->
- {reverse(Acc),Is}.
-
-opt_bs_puts(Is) ->
- opt_bs_1(Is, []).
-
-opt_bs_1([{bs_put,Fail,
- {bs_put_float,1,Flags0},[{integer,Sz},Src]}=I0|Is], Acc) ->
- try eval_put_float(Src, Sz, Flags0) of
- <<Int:Sz>> ->
- Flags = force_big(Flags0),
- I = {bs_put,Fail,{bs_put_integer,1,Flags},
- [{integer,Sz},{integer,Int}]},
- opt_bs_1([I|Is], Acc)
- catch
- error:_ ->
- opt_bs_1(Is, [I0|Acc])
- end;
-opt_bs_1([{bs_put,_,{bs_put_integer,1,_},[{integer,8},{integer,_}]}|_]=IsAll,
- Acc0) ->
- {Is,Acc} = bs_collect_string(IsAll, Acc0),
- opt_bs_1(Is, Acc);
-opt_bs_1([{bs_put,Fail,{bs_put_integer,1,F},[{integer,Sz},{integer,N}]}=I|Is0],
- Acc) when Sz > 8 ->
- case field_endian(F) of
- big ->
- %% We can do this optimization for any field size without
- %% risk for code explosion.
- case bs_split_int(N, Sz, Fail, Is0) of
- no_split -> opt_bs_1(Is0, [I|Acc]);
- Is -> opt_bs_1(Is, Acc)
- end;
- little when Sz < 128 ->
- %% We only try to optimize relatively small fields, to
- %% avoid an explosion in code size.
- <<Int:Sz>> = <<N:Sz/little>>,
- Flags = force_big(F),
- Is = [{bs_put,Fail,{bs_put_integer,1,Flags},
- [{integer,Sz},{integer,Int}]}|Is0],
- opt_bs_1(Is, Acc);
- _ -> %native or too wide little field
- opt_bs_1(Is0, [I|Acc])
- end;
-opt_bs_1([{bs_put,Fail,{Op,U,F},[{integer,Sz},Src]}|Is], Acc) when U > 1 ->
- opt_bs_1([{bs_put,Fail,{Op,1,F},[{integer,U*Sz},Src]}|Is], Acc);
-opt_bs_1([I|Is], Acc) ->
- opt_bs_1(Is, [I|Acc]);
-opt_bs_1([], Acc) -> reverse(Acc).
-
-eval_put_float(Src, Sz, Flags) when Sz =< 256 ->
- %%Only evaluate if Sz is reasonable.
- Val = value(Src),
- case field_endian(Flags) of
- little -> <<Val:Sz/little-float-unit:1>>;
- big -> <<Val:Sz/big-float-unit:1>>
- %% native intentionally not handled here - we can't optimize
- %% it.
- end.
-
-value({integer,I}) -> I;
-value({float,F}) -> F.
-
-bs_collect_string(Is, [{bs_put,_,{bs_put_string,Len,{string,Str}},[]}|Acc]) ->
- bs_coll_str_1(Is, Len, reverse(Str), Acc);
-bs_collect_string(Is, Acc) ->
- bs_coll_str_1(Is, 0, [], Acc).
-
-bs_coll_str_1([{bs_put,_,{bs_put_integer,U,_},[{integer,Sz},{integer,V}]}|Is],
- Len, StrAcc, IsAcc) when U*Sz =:= 8 ->
- Byte = V band 16#FF,
- bs_coll_str_1(Is, Len+1, [Byte|StrAcc], IsAcc);
-bs_coll_str_1(Is, Len, StrAcc, IsAcc) ->
- {Is,[{bs_put,{f,0},{bs_put_string,Len,{string,reverse(StrAcc)}},[]}|IsAcc]}.
-
-field_endian({field_flags,F}) -> field_endian_1(F).
-
-field_endian_1([big=E|_]) -> E;
-field_endian_1([little=E|_]) -> E;
-field_endian_1([native=E|_]) -> E;
-field_endian_1([_|Fs]) -> field_endian_1(Fs).
-
-force_big({field_flags,F}) ->
- {field_flags,force_big_1(F)}.
-
-force_big_1([big|_]=Fs) -> Fs;
-force_big_1([little|Fs]) -> [big|Fs];
-force_big_1([F|Fs]) -> [F|force_big_1(Fs)].
-
-bs_split_int(0, Sz, _, _) when Sz > 64 ->
- %% We don't want to split in this case because the
- %% string will consist of only zeroes.
- no_split;
-bs_split_int(-1, Sz, _, _) when Sz > 64 ->
- %% We don't want to split in this case because the
- %% string will consist of only 255 bytes.
- no_split;
-bs_split_int(N, Sz, Fail, Acc) ->
- FirstByteSz = case Sz rem 8 of
- 0 -> 8;
- Rem -> Rem
- end,
- bs_split_int_1(N, FirstByteSz, Sz, Fail, Acc).
-
-bs_split_int_1(-1, _, Sz, Fail, Acc) when Sz > 64 ->
- I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
- [{integer,Sz},{integer,-1}]},
- [I|Acc];
-bs_split_int_1(0, _, Sz, Fail, Acc) when Sz > 64 ->
- I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
- [{integer,Sz},{integer,0}]},
- [I|Acc];
-bs_split_int_1(N, ByteSz, Sz, Fail, Acc) when Sz > 0 ->
- Mask = (1 bsl ByteSz) - 1,
- I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
- [{integer,ByteSz},{integer,N band Mask}]},
- bs_split_int_1(N bsr ByteSz, 8, Sz-ByteSz, Fail, [I|Acc]);
-bs_split_int_1(_, _, _, _, Acc) -> Acc.
-
-%%%
-%%% Optimization of bit syntax matching: get rid
-%%% of redundant bs_restore2/2 instructions across select_val
-%%% instructions, as well as a few other simple peep-hole
-%%% optimizations.
-%%%
-
-bsm_opt(Is0, Lc0) ->
- {Is1,D0,Lc} = bsm_scan(Is0, [], Lc0, []),
- Is2 = case D0 of
- [] ->
- %% No bit syntax matching in this function.
- Is1;
- [_|_] ->
- %% Optimize the bit syntax matching.
- D = gb_trees:from_orddict(orddict:from_list(D0)),
- bsm_reroute(Is1, D, none, [])
- end,
- Is = beam_clean:bs_clean_saves(Is2),
- {bsm_opt_2(Is, []),Lc}.
-
-bsm_scan([{label,L}=Lbl,{bs_restore2,_,Save}=R|Is], D0, Lc, Acc0) ->
- D = [{{L,Save},Lc}|D0],
- Acc = [{label,Lc},R,Lbl|Acc0],
- bsm_scan(Is, D, Lc+1, Acc);
-bsm_scan([I|Is], D, Lc, Acc) ->
- bsm_scan(Is, D, Lc, [I|Acc]);
-bsm_scan([], D, Lc, Acc) ->
- {reverse(Acc),D,Lc}.
-
-bsm_reroute([{bs_save2,Reg,Save}=I|Is], D, _, Acc) ->
- bsm_reroute(Is, D, {Reg,Save}, [I|Acc]);
-bsm_reroute([{bs_restore2,Reg,Save}=I|Is], D, _, Acc) ->
- bsm_reroute(Is, D, {Reg,Save}, [I|Acc]);
-bsm_reroute([{label,_}=I|Is], D, S, Acc) ->
- bsm_reroute(Is, D, S, [I|Acc]);
-bsm_reroute([{select,select_val,Reg,F0,Lbls0}|Is], D, {_,Save}=S, Acc0) ->
- [F|Lbls] = bsm_subst_labels([F0|Lbls0], Save, D),
- Acc = [{select,select_val,Reg,F,Lbls}|Acc0],
- bsm_reroute(Is, D, S, Acc);
-bsm_reroute([{test,TestOp,F0,TestArgs}=I|Is], D, {_,Save}=S, Acc0) ->
- F = bsm_subst_label(F0, Save, D),
- Acc = [{test,TestOp,F,TestArgs}|Acc0],
- case bsm_not_bs_test(I) of
- true ->
- %% The test instruction will not update the bit offset for
- %% the binary being matched. Therefore the save position
- %% can be kept.
- bsm_reroute(Is, D, S, Acc);
- false ->
- %% The test instruction might update the bit offset. Kill
- %% our remembered Save position.
- bsm_reroute(Is, D, none, Acc)
- end;
-bsm_reroute([{test,TestOp,F0,Live,TestArgs,Dst}|Is], D, {_,Save}, Acc0) ->
- F = bsm_subst_label(F0, Save, D),
- Acc = [{test,TestOp,F,Live,TestArgs,Dst}|Acc0],
- %% The test instruction will update the bit offset. Kill our
- %% remembered Save position.
- bsm_reroute(Is, D, none, Acc);
-bsm_reroute([{block,[{set,[],[],{alloc,_,_}}]}=Bl,
- {bs_context_to_binary,_}=I|Is], D, S, Acc) ->
- %% To help further bit syntax optimizations.
- bsm_reroute([I,Bl|Is], D, S, Acc);
-bsm_reroute([I|Is], D, _, Acc) ->
- bsm_reroute(Is, D, none, [I|Acc]);
-bsm_reroute([], _, _, Acc) -> reverse(Acc).
-
-bsm_opt_2([{test,bs_test_tail2,F,[Ctx,Bits]}|Is],
- [{test,bs_skip_bits2,F,[Ctx,{integer,I},Unit,_Flags]}|Acc]) ->
- bsm_opt_2(Is, [{test,bs_test_tail2,F,[Ctx,Bits+I*Unit]}|Acc]);
-bsm_opt_2([{test,bs_skip_bits2,F,[Ctx,{integer,I1},Unit1,_]}|Is],
- [{test,bs_skip_bits2,F,[Ctx,{integer,I2},Unit2,Flags]}|Acc]) ->
- bsm_opt_2(Is, [{test,bs_skip_bits2,F,
- [Ctx,{integer,I1*Unit1+I2*Unit2},1,Flags]}|Acc]);
-bsm_opt_2([I|Is], Acc) ->
- bsm_opt_2(Is, [I|Acc]);
-bsm_opt_2([], Acc) -> reverse(Acc).
-
-%% bsm_not_bs_test({test,Name,_,Operands}) -> true|false.
-%% Test whether is the test is a "safe", i.e. does not move the
-%% bit offset for a binary.
-%%
-%% 'true' means that the test is safe, 'false' that we don't know or
-%% that the test moves the offset (e.g. bs_get_integer2).
-
-bsm_not_bs_test({test,bs_test_tail2,_,[_,_]}) -> true;
-bsm_not_bs_test(Test) -> beam_utils:is_pure_test(Test).
-
-bsm_subst_labels(Fs, Save, D) ->
- bsm_subst_labels_1(Fs, Save, D, []).
-
-bsm_subst_labels_1([F|Fs], Save, D, Acc) ->
- bsm_subst_labels_1(Fs, Save, D, [bsm_subst_label(F, Save, D)|Acc]);
-bsm_subst_labels_1([], _, _, Acc) ->
- reverse(Acc).
-
-bsm_subst_label({f,Lbl0}=F, Save, D) ->
- case gb_trees:lookup({Lbl0,Save}, D) of
- {value,Lbl} -> {f,Lbl};
- none -> F
- end;
-bsm_subst_label(Other, _, _) -> Other.
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 03:14:36 +0000