diff options
Diffstat (limited to 'lib/compiler/src/beam_bool.erl')
| -rw-r--r-- | lib/compiler/src/beam_bool.erl | 141 |
1 files changed, 57 insertions, 84 deletions
diff --git a/lib/compiler/src/beam_bool.erl b/lib/compiler/src/beam_bool.erl index 5a4621dc37..d14be83496 100644 --- a/lib/compiler/src/beam_bool.erl +++ b/lib/compiler/src/beam_bool.erl @@ -3,16 +3,17 @@ %% %% Copyright Ericsson AB 2004-2013. All Rights Reserved. %% -%% 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 online at http://www.erlang.org/. +%% 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 %% -%% 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. +%% 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% %% @@ -126,44 +127,48 @@ bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) -> %% There was a reference to a boolean expression %% from inside a protected block (try/catch), to %% a boolean expression outside. - throw:protected_barrier -> + throw:protected_barrier -> failed; - %% The 'xor' operator was used. We currently don't - %% find it worthwile to translate 'xor' operators - %% (the code would be clumsy). - throw:'xor' -> + %% The 'xor' operator was used. We currently don't + %% find it worthwile to translate 'xor' operators + %% (the code would be clumsy). + throw:'xor' -> failed; - %% The block does not contain a boolean expression, - %% but only a call to a guard BIF. - %% For instance: ... when element(1, T) -> - throw:not_boolean_expr -> - failed; - - %% The block contains a 'move' instruction that could - %% not be handled. - throw:move -> + %% The block does not contain a boolean expression, + %% but only a call to a guard BIF. + %% For instance: ... when element(1, T) -> + throw:not_boolean_expr -> failed; - %% The optimization is not safe. (A register - %% used by the instructions following the - %% optimized code is either not assigned a - %% value at all or assigned a different value.) - throw:all_registers_not_killed -> + %% The optimization is not safe. (A register + %% used by the instructions following the + %% optimized code is either not assigned a + %% value at all or assigned a different value.) + throw:all_registers_not_killed -> failed; - throw:registers_used -> + throw:registers_used -> + failed; + + %% A protected block refered to the value + %% returned by another protected block, + %% probably because the Core Erlang code + %% used nested try/catches in the guard. + %% (v3_core never produces nested try/catches + %% in guards, so it must have been another + %% Core Erlang translator.) + throw:protected_violation -> failed; - %% A protected block refered to the value - %% returned by another protected block, - %% probably because the Core Erlang code - %% used nested try/catches in the guard. - %% (v3_core never produces nested try/catches - %% in guards, so it must have been another - %% Core Erlang translator.) - throw:protected_violation -> + %% Failed to work out the live registers for a GC + %% BIF. For example, if the number of live registers + %% needed to be 4 because {x,3} was a source register, + %% but {x,2} was not known to be initialized, this + %% exception would be thrown. + throw:gc_bif_alloc_failure -> failed + end end. @@ -205,37 +210,14 @@ ensure_opt_safe(Bl, NewCode, OldIs, Fail, PrecedingCode, St) -> false -> throw(all_registers_not_killed); true -> ok end, - Same = assigned_same_value(Bl, NewCode), MustBeUnused = ordsets:subtract(ordsets:union(NotSet, NewDst), - ordsets:union(MustBeKilled, Same)), + MustBeKilled), case none_used(MustBeUnused, OldIs, Fail, St) of false -> throw(registers_used); true -> ok end, ok. -%% assigned_same_value(OldCode, NewCodeReversed) -> [DestinationRegs] -%% Return an ordset with a list of all y registers that are always -%% assigned the same value in the old and new code. Currently, we -%% are very conservative in that we only consider identical move -%% instructions in the same order. -%% -assigned_same_value(Old, New) -> - case reverse(New) of - [{block,Bl}|_] -> - assigned_same_value(Old, Bl, []); - _ -> - ordsets:new() - end. - -assigned_same_value([{set,[{y,_}=D],[S],move}|T1], - [{set,[{y,_}=D],[S],move}|T2], Acc) -> - assigned_same_value(T1, T2, [D|Acc]); -assigned_same_value(_, _, Acc) -> - ordsets:from_list(Acc). - -update_fail_label([{set,_,_,move}=I|Is], Fail, Acc) -> - update_fail_label(Is, Fail, [I|Acc]); update_fail_label([{set,Ds,As,{bif,N,{f,_}}}|Is], Fail, Acc) -> update_fail_label(Is, Fail, [{set,Ds,As,{bif,N,{f,Fail}}}|Acc]); update_fail_label([{set,Ds,As,{alloc,Regs,{gc_bif,N,{f,_}}}}|Is], Fail, Acc) -> @@ -304,8 +286,6 @@ split_block_1(Is, Fail, ProhibitFailLabel) -> end end. -split_block_2([{set,_,_,move}=I|Is], Fail, Acc) -> - split_block_2(Is, Fail, [I|Acc]); split_block_2([{set,[_],_,{bif,_,{f,Fail}}}=I|Is], Fail, Acc) -> split_block_2(Is, Fail, [I|Acc]); split_block_2([{set,[_],_,{alloc,_,{gc_bif,_,{f,Fail}}}}=I|Is], Fail, Acc) -> @@ -333,8 +313,6 @@ dst_regs([{set,[D],_,{bif,_,{f,_}}}|Is], Acc) -> dst_regs(Is, [D|Acc]); dst_regs([{set,[D],_,{alloc,_,{gc_bif,_,{f,_}}}}|Is], Acc) -> dst_regs(Is, [D|Acc]); -dst_regs([{set,[D],_,move}|Is], Acc) -> - dst_regs(Is, [D|Acc]); dst_regs([_|Is], Acc) -> dst_regs(Is, Acc); dst_regs([], Acc) -> ordsets:from_list(Acc). @@ -401,13 +379,6 @@ bopt_tree([{protected,[Dst],Code,_}|Is], Forest0, Pre) -> _Res -> throw(not_boolean_expr) end; -bopt_tree([{set,[Dst],[Src],move}=Move|Is], Forest, Pre) -> - case {Src,Dst} of - {{tmp,_},_} -> throw(move); - {_,{tmp,_}} -> throw(move); - _ -> ok - end, - bopt_tree(Is, Forest, [Move|Pre]); bopt_tree([{set,[Dst],As,{bif,N,_}}=Bif|Is], Forest0, Pre) -> Ar = length(As), case safe_bool_op(N, Ar) of @@ -579,10 +550,6 @@ free_variables(Is) -> E = gb_sets:empty(), free_vars_1(Is, E, E, E). -free_vars_1([{set,Ds,As,move}|Is], F0, N0, A) -> - F = gb_sets:union(F0, gb_sets:difference(var_list(As), N0)), - N = gb_sets:union(N0, var_list(Ds)), - free_vars_1(Is, F, N, A); free_vars_1([{set,Ds,As,{bif,_,_}}|Is], F0, N0, A) -> F = gb_sets:union(F0, gb_sets:difference(var_list(As), N0)), N = gb_sets:union(N0, var_list(Ds)), @@ -622,8 +589,6 @@ free_vars_regs(X) -> [{x,X-1}|free_vars_regs(X-1)]. rename_regs(Is, Regs) -> rename_regs(Is, Regs, []). -rename_regs([{set,_,_,move}=I|Is], Regs, Acc) -> - rename_regs(Is, Regs, [I|Acc]); rename_regs([{set,[Dst0],Ss0,{alloc,_,Info}}|Is], Regs0, Acc) -> Live = live_regs(Regs0), Ss = rename_sources(Ss0, Regs0), @@ -665,10 +630,16 @@ put_reg_1(V, [], I) -> [{I,V}]. fetch_reg(V, [{I,V}|_]) -> {x,I}; fetch_reg(V, [_|SRs]) -> fetch_reg(V, SRs). -live_regs(Regs) -> - foldl(fun ({I,_}, _) -> - I - end, -1, Regs)+1. +live_regs([{_,reserved}|_]) -> + %% We are not sure that this register is initialized, so we must + %% abort the optimization. + throw(gc_bif_alloc_failure); +live_regs([{I,_}]) -> + I+1; +live_regs([{_,_}|Regs]) -> + live_regs(Regs); +live_regs([]) -> + 0. %%% @@ -721,8 +692,7 @@ ssa_assign({x,_}=R, #ssa{sub=Sub0}=Ssa0) -> Sub1 = gb_trees:update(R, NewReg, Sub0), Sub = gb_trees:insert(NewReg, NewReg, Sub1), Ssa#ssa{sub=Sub} - end; -ssa_assign(_, Ssa) -> Ssa. + end. ssa_sub_list(List, Sub) -> [ssa_sub(E, Sub) || E <- List]. @@ -772,6 +742,9 @@ is_not_used(R, Is, Label, #st{ll=Ll}) -> initialized_regs(Is) -> initialized_regs(Is, ordsets:new()). +initialized_regs([{set,Dst,_Src,{alloc,Live,_}}|_], Regs0) -> + Regs = add_init_regs(free_vars_regs(Live), Regs0), + add_init_regs(Dst, Regs); initialized_regs([{set,Dst,Src,_}|Is], Regs) -> initialized_regs(Is, add_init_regs(Dst, add_init_regs(Src, Regs))); initialized_regs([{test,_,_,Src}|Is], Regs) -> |