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Diffstat (limited to 'lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_block.erl')
| -rw-r--r-- | lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_block.erl | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_block.erl b/lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_block.erl new file mode 100644 index 0000000000..0e3589cdf5 --- /dev/null +++ b/lib/dialyzer/test/options1_SUITE_data/src/compiler/beam_block.erl @@ -0,0 +1,601 @@ +%% ``The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved via the world wide web at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% The Initial Developer of the Original Code is Ericsson Utvecklings AB. +%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings +%% AB. All Rights Reserved.'' +%% +%% $Id: beam_block.erl,v 1.1 2008/12/17 09:53:41 mikpe Exp $ +%% +%% Purpose : Partitions assembly instructions into basic blocks and +%% optimizes them. + +-module(beam_block). + +-export([module/2]). +-export([live_at_entry/1]). %Used by beam_type, beam_bool. +-export([is_killed/2]). %Used by beam_dead, beam_type, beam_bool. +-export([is_not_used/2]). %Used by beam_bool. +-export([merge_blocks/2]). %Used by beam_jump. +-import(lists, [map/2,mapfoldr/3,reverse/1,reverse/2,foldl/3, + member/2,sort/1,all/2]). +-define(MAXREG, 1024). + +module({Mod,Exp,Attr,Fs,Lc}, _Opt) -> + {ok,{Mod,Exp,Attr,map(fun function/1, Fs),Lc}}. + +function({function,Name,Arity,CLabel,Is0}) -> + %% Collect basic blocks and optimize them. + Is = blockify(Is0), + + %% Done. + {function,Name,Arity,CLabel,Is}. + +%% blockify(Instructions0) -> Instructions +%% Collect sequences of instructions to basic blocks and +%% optimize the contents of the blocks. Also do some simple +%% optimations on instructions outside the blocks. + +blockify(Is) -> + blockify(Is, []). + +blockify([{loop_rec,{f,Fail},{x,0}},{loop_rec_end,_Lbl},{label,Fail}|Is], Acc) -> + %% Useless instruction sequence. + blockify(Is, Acc); +blockify([{test,bs_test_tail,F,[Bits]}|Is], + [{test,bs_skip_bits,F,[{integer,I},Unit,_Flags]}|Acc]) -> + blockify(Is, [{test,bs_test_tail,F,[Bits+I*Unit]}|Acc]); +blockify([{test,bs_skip_bits,F,[{integer,I1},Unit1,_]}|Is], + [{test,bs_skip_bits,F,[{integer,I2},Unit2,Flags]}|Acc]) -> + blockify(Is, [{test,bs_skip_bits,F, + [{integer,I1*Unit1+I2*Unit2},1,Flags]}|Acc]); +blockify([{test,is_atom,{f,Fail},[Reg]}=I| + [{select_val,Reg,{f,Fail}, + {list,[{atom,false},{f,_}=BrFalse, + {atom,true}=AtomTrue,{f,_}=BrTrue]}}|Is]=Is0], + [{block,Bl}|_]=Acc) -> + case is_last_bool(Bl, Reg) of + false -> + blockify(Is0, [I|Acc]); + true -> + blockify(Is, [{jump,BrTrue}, + {test,is_eq_exact,BrFalse,[Reg,AtomTrue]}|Acc]) + end; +blockify([{test,is_atom,{f,Fail},[Reg]}=I| + [{select_val,Reg,{f,Fail}, + {list,[{atom,true}=AtomTrue,{f,_}=BrTrue, + {atom,false},{f,_}=BrFalse]}}|Is]=Is0], + [{block,Bl}|_]=Acc) -> + case is_last_bool(Bl, Reg) of + false -> + blockify(Is0, [I|Acc]); + true -> + blockify(Is, [{jump,BrTrue}, + {test,is_eq_exact,BrFalse,[Reg,AtomTrue]}|Acc]) + end; +blockify([I|Is0]=IsAll, Acc) -> + case is_bs_put(I) of + true -> + {BsPuts0,Is} = collect_bs_puts(IsAll), + BsPuts = opt_bs_puts(BsPuts0), + blockify(Is, reverse(BsPuts, Acc)); + false -> + case collect(I) of + error -> blockify(Is0, [I|Acc]); + Instr when is_tuple(Instr) -> + {Block0,Is} = collect_block(IsAll), + Block = opt_block(Block0), + blockify(Is, [{block,Block}|Acc]) + end + end; +blockify([], Acc) -> reverse(Acc). + +is_last_bool([I,{'%live',_}], Reg) -> + is_last_bool([I], Reg); +is_last_bool([{set,[Reg],As,{bif,N,_}}], Reg) -> + Ar = length(As), + erl_internal:new_type_test(N, Ar) orelse erl_internal:comp_op(N, Ar) + orelse erl_internal:bool_op(N, Ar); +is_last_bool([_|Is], Reg) -> is_last_bool(Is, Reg); +is_last_bool([], _) -> false. + +collect_block(Is) -> + collect_block(Is, []). + +collect_block([{allocate_zero,Ns,R},{test_heap,Nh,R}|Is], Acc) -> + collect_block(Is, [{allocate,R,{no_opt,Ns,Nh,[]}}|Acc]); +collect_block([I|Is]=Is0, Acc) -> + case collect(I) of + error -> {reverse(Acc),Is0}; + Instr -> collect_block(Is, [Instr|Acc]) + end; +collect_block([], Acc) -> {reverse(Acc),[]}. + +collect({allocate_zero,N,R}) -> {allocate,R,{zero,N,0,[]}}; +collect({test_heap,N,R}) -> {allocate,R,{nozero,nostack,N,[]}}; +collect({bif,N,nofail,As,D}) -> {set,[D],As,{bif,N}}; +collect({bif,N,F,As,D}) -> {set,[D],As,{bif,N,F}}; +collect({move,S,D}) -> {set,[D],[S],move}; +collect({put_list,S1,S2,D}) -> {set,[D],[S1,S2],put_list}; +collect({put_tuple,A,D}) -> {set,[D],[],{put_tuple,A}}; +collect({put,S}) -> {set,[],[S],put}; +collect({put_string,L,S,D}) -> {set,[D],[],{put_string,L,S}}; +collect({get_tuple_element,S,I,D}) -> {set,[D],[S],{get_tuple_element,I}}; +collect({set_tuple_element,S,D,I}) -> {set,[],[S,D],{set_tuple_element,I}}; +collect({get_list,S,D1,D2}) -> {set,[D1,D2],[S],get_list}; +collect(remove_message) -> {set,[],[],remove_message}; +collect({'catch',R,L}) -> {set,[R],[],{'catch',L}}; +collect({'%live',_}=Live) -> Live; +collect(_) -> error. + +opt_block(Is0) -> + %% We explicitly move any allocate instruction upwards before optimising + %% moves, to avoid any potential problems with the calculation of live + %% registers. + Is1 = find_fixpoint(fun move_allocates/1, Is0), + Is2 = find_fixpoint(fun opt/1, Is1), + Is = opt_alloc(Is2), + share_floats(Is). + +find_fixpoint(OptFun, Is0) -> + case OptFun(Is0) of + Is0 -> Is0; + Is1 -> find_fixpoint(OptFun, Is1) + end. + +move_allocates([{set,_Ds,_Ss,{set_tuple_element,_}}|_]=Is) -> Is; +move_allocates([{set,Ds,Ss,_Op}=Set,{allocate,R,Alloc}|Is]) when is_integer(R) -> + [{allocate,live_regs(Ds, Ss, R),Alloc},Set|Is]; +move_allocates([{allocate,R1,Alloc1},{allocate,R2,Alloc2}|Is]) -> + R1 = R2, % Assertion. + move_allocates([{allocate,R1,combine_alloc(Alloc1, Alloc2)}|Is]); +move_allocates([I|Is]) -> + [I|move_allocates(Is)]; +move_allocates([]) -> []. + +combine_alloc({_,Ns,Nh1,Init}, {_,nostack,Nh2,[]}) -> + {zero,Ns,Nh1+Nh2,Init}. + +merge_blocks([{allocate,R,{Attr,Ns,Nh1,Init}}|B1], + [{allocate,_,{_,nostack,Nh2,[]}}|B2]) -> + Alloc = {allocate,R,{Attr,Ns,Nh1+Nh2,Init}}, + [Alloc|merge_blocks(B1, B2)]; +merge_blocks(B1, B2) -> merge_blocks_1(B1++[{set,[],[],stop_here}|B2]). + +merge_blocks_1([{set,[],_,stop_here}|Is]) -> Is; +merge_blocks_1([{set,[D],_,move}=I|Is]) -> + case is_killed(D, Is) of + true -> merge_blocks_1(Is); + false -> [I|merge_blocks_1(Is)] + end; +merge_blocks_1([I|Is]) -> [I|merge_blocks_1(Is)]. + +opt([{set,[Dst],As,{bif,Bif,Fail}}=I1, + {set,[Dst],[Dst],{bif,'not',Fail}}=I2|Is]) -> + %% Get rid of the 'not' if the operation can be inverted. + case inverse_comp_op(Bif) of + none -> [I1,I2|opt(Is)]; + RevBif -> [{set,[Dst],As,{bif,RevBif,Fail}}|opt(Is)] + end; +opt([{set,[X],[X],move}|Is]) -> opt(Is); +opt([{set,[D1],[{integer,Idx1},Reg],{bif,element,{f,0}}}=I1, + {set,[D2],[{integer,Idx2},Reg],{bif,element,{f,0}}}=I2|Is]) + when Idx1 < Idx2, D1 =/= D2, D1 =/= Reg, D2 =/= Reg -> + opt([I2,I1|Is]); +opt([{set,Ds0,Ss,Op}|Is0]) -> + {Ds,Is} = opt_moves(Ds0, Is0), + [{set,Ds,Ss,Op}|opt(Is)]; +opt([I|Is]) -> [I|opt(Is)]; +opt([]) -> []. + +opt_moves([], Is0) -> {[],Is0}; +opt_moves([D0], Is0) -> + {D1,Is1} = opt_move(D0, Is0), + {[D1],Is1}; +opt_moves([X0,Y0]=Ds, Is0) -> + {X1,Is1} = opt_move(X0, Is0), + case opt_move(Y0, Is1) of + {Y1,Is2} when X1 =/= Y1 -> {[X1,Y1],Is2}; + _Other when X1 =/= Y0 -> {[X1,Y0],Is1}; + _Other -> {Ds,Is0} + end. + +opt_move(R, [{set,[D],[R],move}|Is]=Is0) -> + case is_killed(R, Is) of + true -> {D,Is}; + false -> {R,Is0} + end; +opt_move(R, [I|Is0]) -> + case is_transparent(R, I) of + true -> + {D,Is1} = opt_move(R, Is0), + case is_transparent(D, I) of + true -> {D,[I|Is1]}; + false -> {R,[I|Is0]} + end; + false -> {R,[I|Is0]} + end; +opt_move(R, []) -> {R,[]}. + +is_transparent(R, {set,Ds,Ss,_Op}) -> + case member(R, Ds) of + true -> false; + false -> not member(R, Ss) + end; +is_transparent(_, _) -> false. + +%% is_killed(Register, [Instruction]) -> true|false +%% Determine whether a register is killed by the instruction sequence. +%% If true is returned, it means that the register will not be +%% referenced in ANY way (not even indirectly by an allocate instruction); +%% i.e. it is OK to enter the instruction sequence with Register +%% containing garbage. + +is_killed({x,N}=R, [{block,Blk}|Is]) -> + case is_killed(R, Blk) of + true -> true; + false -> + %% Before looking beyond the block, we must be + %% sure that the register is not referenced by + %% any allocate instruction in the block. + case all(fun({allocate,Live,_}) when N < Live -> false; + (_) -> true + end, Blk) of + true -> is_killed(R, Is); + false -> false + end + end; +is_killed(R, [{block,Blk}|Is]) -> + case is_killed(R, Blk) of + true -> true; + false -> is_killed(R, Is) + end; +is_killed(R, [{set,Ds,Ss,_Op}|Is]) -> + case member(R, Ss) of + true -> false; + false -> + case member(R, Ds) of + true -> true; + false -> is_killed(R, Is) + end + end; +is_killed(R, [{case_end,Used}|_]) -> R =/= Used; +is_killed(R, [{badmatch,Used}|_]) -> R =/= Used; +is_killed(_, [if_end|_]) -> true; +is_killed(R, [{func_info,_,_,Ar}|_]) -> + case R of + {x,X} when X < Ar -> false; + _ -> true + end; +is_killed(R, [{kill,R}|_]) -> true; +is_killed(R, [{kill,_}|Is]) -> is_killed(R, Is); +is_killed(R, [{bs_init2,_,_,_,_,_,Dst}|Is]) -> + if + R =:= Dst -> true; + true -> is_killed(R, Is) + end; +is_killed(R, [{bs_put_string,_,_}|Is]) -> is_killed(R, Is); +is_killed({x,R}, [{'%live',Live}|_]) when R >= Live -> true; +is_killed({x,R}, [{'%live',_}|Is]) -> is_killed(R, Is); +is_killed({x,R}, [{allocate,Live,_}|_]) -> + %% Note: To be safe here, we must return either true or false, + %% not looking further at the instructions beyond the allocate + %% instruction. + R >= Live; +is_killed({x,R}, [{call,Live,_}|_]) when R >= Live -> true; +is_killed({x,R}, [{call_last,Live,_,_}|_]) when R >= Live -> true; +is_killed({x,R}, [{call_only,Live,_}|_]) when R >= Live -> true; +is_killed({x,R}, [{call_ext,Live,_}|_]) when R >= Live -> true; +is_killed({x,R}, [{call_ext_last,Live,_,_}|_]) when R >= Live -> true; +is_killed({x,R}, [{call_ext_only,Live,_}|_]) when R >= Live -> true; +is_killed({x,R}, [return|_]) when R > 0 -> true; +is_killed(_, _) -> false. + +%% is_not_used(Register, [Instruction]) -> true|false +%% Determine whether a register is used by the instruction sequence. +%% If true is returned, it means that the register will not be +%% referenced directly, but it may be referenced by an allocate +%% instruction (meaning that it is NOT allowed to contain garbage). + +is_not_used(R, [{block,Blk}|Is]) -> + case is_not_used(R, Blk) of + true -> true; + false -> is_not_used(R, Is) + end; +is_not_used({x,R}=Reg, [{allocate,Live,_}|Is]) -> + if + R >= Live -> true; + true -> is_not_used(Reg, Is) + end; +is_not_used(R, [{set,Ds,Ss,_Op}|Is]) -> + case member(R, Ss) of + true -> false; + false -> + case member(R, Ds) of + true -> true; + false -> is_not_used(R, Is) + end + end; +is_not_used(R, Is) -> is_killed(R, Is). + +%% opt_alloc(Instructions) -> Instructions' +%% Optimises all allocate instructions. + +opt_alloc([{allocate,R,{_,Ns,Nh,[]}}|Is]) -> + [opt_alloc(Is, Ns, Nh, R)|opt(Is)]; +opt_alloc([I|Is]) -> [I|opt_alloc(Is)]; +opt_alloc([]) -> []. + +%% opt_alloc(Instructions, FrameSize, HeapNeed, LivingRegs) -> [Instr] +%% Generates the optimal sequence of instructions for +%% allocating and initalizing the stack frame and needed heap. + +opt_alloc(_Is, nostack, Nh, LivingRegs) -> + {allocate,LivingRegs,{nozero,nostack,Nh,[]}}; +opt_alloc(Is, Ns, Nh, LivingRegs) -> + InitRegs = init_yreg(Is, 0), + case count_ones(InitRegs) of + N when N*2 > Ns -> + {allocate,LivingRegs,{nozero,Ns,Nh,gen_init(Ns, InitRegs)}}; + _ -> + {allocate,LivingRegs,{zero,Ns,Nh,[]}} + end. + +gen_init(Fs, Regs) -> gen_init(Fs, Regs, 0, []). + +gen_init(SameFs, _Regs, SameFs, Acc) -> reverse(Acc); +gen_init(Fs, Regs, Y, Acc) when Regs band 1 == 0 -> + gen_init(Fs, Regs bsr 1, Y+1, [{init, {y,Y}}|Acc]); +gen_init(Fs, Regs, Y, Acc) -> + gen_init(Fs, Regs bsr 1, Y+1, Acc). + +%% init_yreg(Instructions, RegSet) -> RegSetInitialized +%% Calculate the set of initialized y registers. + +init_yreg([{set,_,_,{bif,_,_}}|_], Reg) -> Reg; +init_yreg([{set,Ds,_,_}|Is], Reg) -> init_yreg(Is, add_yregs(Ds, Reg)); +init_yreg(_Is, Reg) -> Reg. + +add_yregs(Ys, Reg) -> foldl(fun(Y, R0) -> add_yreg(Y, R0) end, Reg, Ys). + +add_yreg({y,Y}, Reg) -> Reg bor (1 bsl Y); +add_yreg(_, Reg) -> Reg. + +count_ones(Bits) -> count_ones(Bits, 0). +count_ones(0, Acc) -> Acc; +count_ones(Bits, Acc) -> + count_ones(Bits bsr 1, Acc + (Bits band 1)). + +%% live_at_entry(Is) -> NumberOfRegisters +%% Calculate the number of register live at the entry to the code +%% sequence. + +live_at_entry([{block,[{allocate,R,_}|_]}|_]) -> + R; +live_at_entry([{label,_}|Is]) -> + live_at_entry(Is); +live_at_entry([{block,Bl}|_]) -> + live_at_entry(Bl); +live_at_entry([{func_info,_,_,Ar}|_]) -> + Ar; +live_at_entry(Is0) -> + case reverse(Is0) of + [{'%live',Regs}|Is] -> live_at_entry_1(Is, (1 bsl Regs)-1); + _ -> unknown + end. + +live_at_entry_1([{set,Ds,Ss,_}|Is], Rset0) -> + Rset = x_live(Ss, x_dead(Ds, Rset0)), + live_at_entry_1(Is, Rset); +live_at_entry_1([{allocate,_,_}|Is], Rset) -> + live_at_entry_1(Is, Rset); +live_at_entry_1([], Rset) -> live_regs_1(0, Rset). + +%% Calculate the new number of live registers when we move an allocate +%% instruction upwards, passing a 'set' instruction. + +live_regs(Ds, Ss, Regs0) -> + Rset = x_live(Ss, x_dead(Ds, (1 bsl Regs0)-1)), + live_regs_1(0, Rset). + +live_regs_1(N, 0) -> N; +live_regs_1(N, Regs) -> live_regs_1(N+1, Regs bsr 1). + +x_dead([{x,N}|Rs], Regs) -> x_dead(Rs, Regs band (bnot (1 bsl N))); +x_dead([_|Rs], Regs) -> x_dead(Rs, Regs); +x_dead([], Regs) -> Regs. + +x_live([{x,N}|Rs], Regs) -> x_live(Rs, Regs bor (1 bsl N)); +x_live([_|Rs], Regs) -> x_live(Rs, Regs); +x_live([], Regs) -> Regs. + +%% +%% If a floating point literal occurs more than once, move it into +%% a free register and re-use it. +%% + +share_floats([{allocate,_,_}=Alloc|Is]) -> + [Alloc|share_floats(Is)]; +share_floats(Is0) -> + All = get_floats(Is0, []), + MoreThanOnce0 = more_than_once(sort(All), gb_sets:empty()), + case gb_sets:is_empty(MoreThanOnce0) of + true -> Is0; + false -> + MoreThanOnce = gb_sets:to_list(MoreThanOnce0), + FreeX = highest_used(Is0, -1) + 1, + Regs0 = make_reg_map(MoreThanOnce, FreeX, []), + Regs = gb_trees:from_orddict(Regs0), + Is = map(fun({set,Ds,[{float,F}],Op}=I) -> + case gb_trees:lookup(F, Regs) of + none -> I; + {value,R} -> {set,Ds,[R],Op} + end; + (I) -> I + end, Is0), + [{set,[R],[{float,F}],move} || {F,R} <- Regs0] ++ Is + end. + +get_floats([{set,_,[{float,F}],_}|Is], Acc) -> + get_floats(Is, [F|Acc]); +get_floats([_|Is], Acc) -> + get_floats(Is, Acc); +get_floats([], Acc) -> Acc. + +more_than_once([F,F|Fs], Set) -> + more_than_once(Fs, gb_sets:add(F, Set)); +more_than_once([_|Fs], Set) -> + more_than_once(Fs, Set); +more_than_once([], Set) -> Set. + +highest_used([{set,Ds,Ss,_}|Is], High) -> + highest_used(Is, highest(Ds, highest(Ss, High))); +highest_used([{'%live',Live}|Is], High) when Live > High -> + highest_used(Is, Live); +highest_used([_|Is], High) -> + highest_used(Is, High); +highest_used([], High) -> High. + +highest([{x,R}|Rs], High) when R > High -> + highest(Rs, R); +highest([_|Rs], High) -> + highest(Rs, High); +highest([], High) -> High. + +make_reg_map([F|Fs], R, Acc) when R < ?MAXREG -> + make_reg_map(Fs, R+1, [{F,{x,R}}|Acc]); +make_reg_map(_, _, Acc) -> sort(Acc). + +%% inverse_comp_op(Op) -> none|RevOp + +inverse_comp_op('=:=') -> '=/='; +inverse_comp_op('=/=') -> '=:='; +inverse_comp_op('==') -> '/='; +inverse_comp_op('/=') -> '=='; +inverse_comp_op('>') -> '=<'; +inverse_comp_op('<') -> '>='; +inverse_comp_op('>=') -> '<'; +inverse_comp_op('=<') -> '>'; +inverse_comp_op(_) -> none. + +%%% +%%% Evaluation of constant bit fields. +%%% + +is_bs_put({bs_put_integer,_,_,_,_,_}) -> true; +is_bs_put({bs_put_float,_,_,_,_,_}) -> true; +is_bs_put(_) -> false. + +collect_bs_puts(Is) -> + collect_bs_puts_1(Is, []). + +collect_bs_puts_1([I|Is]=Is0, Acc) -> + case is_bs_put(I) of + false -> {reverse(Acc),Is0}; + true -> collect_bs_puts_1(Is, [I|Acc]) + end; +collect_bs_puts_1([], Acc) -> {reverse(Acc),[]}. + +opt_bs_puts(Is) -> + opt_bs_1(Is, []). + +opt_bs_1([{bs_put_float,Fail,{integer,Sz},1,Flags0,Src}=I0|Is], Acc) -> + case catch eval_put_float(Src, Sz, Flags0) of + {'EXIT',_} -> + opt_bs_1(Is, [I0|Acc]); + <<Int:Sz>> -> + Flags = force_big(Flags0), + I = {bs_put_integer,Fail,{integer,Sz},1,Flags,{integer,Int}}, + opt_bs_1([I|Is], Acc) + end; +opt_bs_1([{bs_put_integer,_,{integer,8},1,_,{integer,_}}|_]=IsAll, Acc0) -> + {Is,Acc} = bs_collect_string(IsAll, Acc0), + opt_bs_1(Is, Acc); +opt_bs_1([{bs_put_integer,Fail,{integer,Sz},1,F,{integer,N}}=I|Is0], Acc) when Sz > 8 -> + case field_endian(F) of + big -> + 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 -> + case catch <<N:Sz/little>> of + {'EXIT',_} -> + opt_bs_1(Is0, [I|Acc]); + <<Int:Sz>> -> + Flags = force_big(F), + Is = [{bs_put_integer,Fail,{integer,Sz},1, + Flags,{integer,Int}}|Is0], + opt_bs_1(Is, Acc) + end; + native -> opt_bs_1(Is0, [I|Acc]) + end; +opt_bs_1([{Op,Fail,{integer,Sz},U,F,Src}|Is], Acc) when U > 1 -> + opt_bs_1([{Op,Fail,{integer,U*Sz},1,F,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) -> + 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; +value({atom,A}) -> A. + +bs_collect_string(Is, [{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_integer,_,{integer,Sz},U,_,{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_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(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(N, ByteSz, Sz, Fail, Acc) when Sz > 0 -> + Mask = (1 bsl ByteSz) - 1, + I = {bs_put_integer,Fail,{integer,ByteSz},1, + {field_flags,[big]},{integer,N band Mask}}, + bs_split_int_1(N bsr ByteSz, 8, Sz-ByteSz, Fail, [I|Acc]); +bs_split_int_1(_, _, _, _, Acc) -> Acc. |