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Diffstat (limited to 'lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/beam_bool.erl')
| -rw-r--r-- | lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/beam_bool.erl | 617 |
1 files changed, 0 insertions, 617 deletions
diff --git a/lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/beam_bool.erl b/lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/beam_bool.erl deleted file mode 100644 index 3180a22433..0000000000 --- a/lib/dialyzer/test/options1_tests_SUITE_data/src/compiler/beam_bool.erl +++ /dev/null @@ -1,617 +0,0 @@ -%% ``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_bool.erl,v 1.1 2008/12/17 09:53:41 mikpe Exp $ -%% -%% Purpose: Optimizes booleans in guards. - --module(beam_bool). - --export([module/2]). - --import(lists, [reverse/1,foldl/3,mapfoldl/3,sort/1,member/2]). --define(MAXREG, 1024). - --record(st, - {next, %Next label number. - ll %Live regs at labels. - }). - -module({Mod,Exp,Attr,Fs0,Lc}, _Opts) -> - %%io:format("~p:\n", [Mod]), - {Fs,_} = mapfoldl(fun(Fn, Lbl) -> function(Fn, Lbl) end, 100000000, Fs0), - {ok,{Mod,Exp,Attr,Fs,Lc}}. - -function({function,Name,Arity,CLabel,Is0}, Lbl0) -> - %%io:format("~p/~p:\n", [Name,Arity]), - {Is,#st{next=Lbl}} = bool_opt(Is0, Lbl0), - {{function,Name,Arity,CLabel,Is},Lbl}. - -%% -%% Optimize boolean expressions that use guard bifs. Rewrite to -%% use test instructions if possible. -%% - -bool_opt(Asm, Lbl) -> - LiveInfo = index_instructions(Asm), - bopt(Asm, [], #st{next=Lbl,ll=LiveInfo}). - -bopt([{block,Bl0}=Block| - [{jump,{f,Succ}}, - {label,Fail}, - {block,[{set,[Dst],[{atom,false}],move},{'%live',Live}]}, - {label,Succ}|Is]=Is0], Acc0, St) -> - case split_block(Bl0, Dst, Fail) of - failed -> - bopt(Is0, [Block|Acc0], St); - {Bl,PreBlock} -> - Acc1 = case PreBlock of - [] -> Acc0; - _ -> [{block,PreBlock}|Acc0] - end, - Acc = [{protected,[Dst],Bl,{Fail,Succ,Live}}|Acc1], - bopt(Is, Acc, St) - end; -bopt([{test,is_eq_exact,{f,Fail},[Reg,{atom,true}]}=I|Is], [{block,_}|_]=Acc0, St0) -> - case bopt_block(Reg, Fail, Is, Acc0, St0) of - failed -> bopt(Is, [I|Acc0], St0); - {Acc,St} -> bopt(Is, Acc, St) - end; -bopt([I|Is], Acc, St) -> - bopt(Is, [I|Acc], St); -bopt([], Acc, St) -> - {bopt_reverse(Acc, []),St}. - -bopt_reverse([{protected,[Dst],Block,{Fail,Succ,Live}}|Is], Acc0) -> - Acc = [{block,Block},{jump,{f,Succ}}, - {label,Fail}, - {block,[{set,[Dst],[{atom,false}],move},{'%live',Live}]}, - {label,Succ}|Acc0], - bopt_reverse(Is, Acc); -bopt_reverse([I|Is], Acc) -> - bopt_reverse(Is, [I|Acc]); -bopt_reverse([], Acc) -> Acc. - -%% bopt_block(Reg, Fail, OldIs, Accumulator, St) -> failed | {NewAcc,St} -%% Attempt to optimized a block of guard BIFs followed by a test -%% instruction. -bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) -> - case split_block(Bl0, Reg, Fail) of - failed -> - %% Reason for failure: The block either contained no - %% guard BIFs with the failure label Fail, or the final - %% instruction in the block did not assign the Reg register. - - %%io:format("split ~p: ~P\n", [Reg,Bl0,20]), - failed; - {Bl1,BlPre} -> - %% The block has been splitted. Bl1 is a non-empty list - %% of guard BIF instructions having the failure label Fail. - %% BlPre is a (possibly empty list) of instructions preceeding - %% Bl1. - Acc1 = make_block(BlPre, Acc0), - {Bl,Acc} = extend_block(Bl1, Fail, Acc1), - case catch bopt_block_1(Bl, Fail, St0) of - {'EXIT',_Reason} -> - %% Optimization failed for one of the following reasons: - %% - %% 1. Not possible to rewrite because a boolean value is - %% passed to another guard bif, e.g. 'abs(A > B)' - %% (in this case, obviously nonsense code). Rare in - %% practice. - %% - %% 2. Not possible to rewrite because we have not seen - %% the complete boolan expression (it is spread out - %% over several blocks with jumps and labels). - %% The 'or' and 'and' instructions need to that fully - %% known operands in order to be eliminated. - %% - %% 3. Other bug or limitation. - - %%io:format("~P\n", [_Reason,20]), - failed; - {NewCode,St} -> - case is_opt_safe(Bl, NewCode, OldIs, St) of - false -> - %% 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.) - - %%io:format("\nNot safe:\n"), - %%io:format("~p\n", [Bl]), - %%io:format("~p\n", [reverse(NewCode)]), - failed; - true -> {NewCode++Acc,St} - end - end - end. - -bopt_block_1(Block, Fail, St) -> - {Pre0,[{_,Tree}]} = bopt_tree(Block), - Pre = update_fail_label(Pre0, Fail, []), - bopt_cg(Tree, Fail, make_block(Pre, []), St). - -%% is_opt_safe(OriginalCode, OptCode, FollowingCode, State) -> true|false -%% Comparing the original code to the optimized code, determine -%% whether the optimized code is guaranteed to work in the same -%% way as the original code. - -is_opt_safe(Bl, NewCode, OldIs, St) -> - %% Here are the conditions that must be true for the - %% optimization to be safe. - %% - %% 1. Any register that was assigned a value in the original - %% code, but is not in the optimized code, must be guaranteed - %% to be KILLED in the following code. (NotSet below.) - %% - %% 2. Any register that is assigned a value in the optimized - %% code must be UNUSED in the following code. (NewDst, Set.) - %% (Possible future improvement: Registers that are known - %% to be assigned the SAME value in the original and optimized - %% code don't need to be unused in the following code.) - - PrevDst = dst_regs(Bl), - NewDst = dst_regs(NewCode), - NotSet = ordsets:subtract(PrevDst, NewDst), - - %% Note: The following line is an optimization. We don't need - %% to test whether variables in NotSet for being unused, because - %% they will all be tested for being killed (a stronger condition - %% than being unused). - - Set = ordsets:subtract(NewDst, NotSet), - - all_killed(NotSet, OldIs, St) andalso - none_used(Set, OldIs, St). - -% update_fail_label([{set,_,_,{bif,_,{f,0}}}=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([], _, Acc) -> Acc. - -make_block([], Acc) -> Acc; -make_block(Bl, Acc) -> [{block,Bl}|Acc]. - -extend_block(BlAcc, Fail, [{protected,_,_,_}=Prot|OldAcc]) -> - extend_block([Prot|BlAcc], Fail, OldAcc); -extend_block(BlAcc0, Fail, [{block,Is0}|OldAcc]=OldAcc0) -> - case extend_block_1(reverse(Is0), Fail, BlAcc0) of - {[],_} -> {BlAcc0,OldAcc0}; - {BlAcc,[]} -> extend_block(BlAcc, Fail, OldAcc); - {BlAcc,Is} -> {BlAcc,[{block,Is}|OldAcc]} - end; -extend_block(BlAcc, _, OldAcc) -> {BlAcc,OldAcc}. - -extend_block_1([{set,[_],_,{bif,_,{f,Fail}}}=I|Is], Fail, Acc) -> - extend_block_1(Is, Fail, [I|Acc]); -extend_block_1([{set,[_],As,{bif,Bif,_}}=I|Is]=Is0, Fail, Acc) -> - case safe_bool_op(Bif, length(As)) of - false -> {Acc,reverse(Is0)}; - true -> extend_block_1(Is, Fail, [I|Acc]) - end; -extend_block_1([_|_]=Is, _, Acc) -> {Acc,reverse(Is)}; -extend_block_1([], _, Acc) -> {Acc,[]}. - -split_block(Is0, Dst, Fail) -> - case reverse(Is0) of - [{'%live',_}|[{set,[Dst],_,_}|_]=Is] -> - split_block_1(Is, Fail); - [{set,[Dst],_,_}|_]=Is -> - split_block_1(Is, Fail); - _ -> failed - end. - -split_block_1(Is, Fail) -> - case split_block_2(Is, Fail, []) of - {[],_} -> failed; - {_,_}=Res -> Res - end. - -% split_block_2([{set,[_],_,{bif,_,{f,0}}}=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([{'%live',_}|Is], Fail, Acc) -> - split_block_2(Is, Fail, Acc); -split_block_2(Is, _, Acc) -> {Acc,reverse(Is)}. - -dst_regs(Is) -> - dst_regs(Is, []). - -dst_regs([{block,Bl}|Is], Acc) -> - dst_regs(Bl, dst_regs(Is, Acc)); -dst_regs([{set,[D],_,{bif,_,{f,_}}}|Is], Acc) -> - dst_regs(Is, [D|Acc]); -dst_regs([_|Is], Acc) -> - dst_regs(Is, Acc); -dst_regs([], Acc) -> ordsets:from_list(Acc). - -all_killed([R|Rs], OldIs, St) -> - case is_killed(R, OldIs, St) of - false -> false; - true -> all_killed(Rs, OldIs, St) - end; -all_killed([], _, _) -> true. - -none_used([R|Rs], OldIs, St) -> - case is_not_used(R, OldIs, St) of - false -> false; - true -> none_used(Rs, OldIs, St) - end; -none_used([], _, _) -> true. - -bopt_tree(Block0) -> - Block = ssa_block(Block0), - Reg = free_variables(Block), - %%io:format("~p\n", [Block]), - %%io:format("~p\n", [Reg]), - Res = bopt_tree_1(Block, Reg, []), - %%io:format("~p\n", [Res]), - Res. - -bopt_tree_1([{set,[Dst],As0,{bif,'not',_}}|Is], Forest0, Pre) -> - {[Arg],Forest1} = bopt_bool_args(As0, Forest0), - Forest = gb_trees:enter(Dst, {'not',Arg}, Forest1), - bopt_tree_1(Is, Forest, Pre); -bopt_tree_1([{set,[Dst],As0,{bif,'and',_}}|Is], Forest0, Pre) -> - {As,Forest1} = bopt_bool_args(As0, Forest0), - AndList = make_and_list(As), - Forest = gb_trees:enter(Dst, {'and',AndList}, Forest1), - bopt_tree_1(Is, Forest, Pre); -bopt_tree_1([{set,[Dst],[L0,R0],{bif,'or',_}}|Is], Forest0, Pre) -> - L = gb_trees:get(L0, Forest0), - R = gb_trees:get(R0, Forest0), - Forest1 = gb_trees:delete(L0, gb_trees:delete(R0, Forest0)), - OrList = make_or_list([L,R]), - Forest = gb_trees:enter(Dst, {'or',OrList}, Forest1), - bopt_tree_1(Is, Forest, Pre); -bopt_tree_1([{protected,[Dst],_,_}=Prot|Is], Forest0, Pre) -> - Forest = gb_trees:enter(Dst, Prot, Forest0), - bopt_tree_1(Is, Forest, Pre); -bopt_tree_1([{set,[Dst],As,{bif,N,_}}=Bif|Is], Forest0, Pre) -> - Ar = length(As), - case safe_bool_op(N, Ar) of - false -> - bopt_good_args(As, Forest0), - Forest = gb_trees:enter(Dst, any, Forest0), - bopt_tree_1(Is, Forest, [Bif|Pre]); - true -> - bopt_good_args(As, Forest0), - Test = bif_to_test(Dst, N, As), - Forest = gb_trees:enter(Dst, Test, Forest0), - bopt_tree_1(Is, Forest, Pre) - end; -bopt_tree_1([], Forest, Pre) -> - {Pre,[R || {_,V}=R <- gb_trees:to_list(Forest), V =/= any]}. - -safe_bool_op(internal_is_record, 3) -> true; -safe_bool_op(N, Ar) -> - erl_internal:new_type_test(N, Ar) orelse erl_internal:comp_op(N, Ar). - -bopt_bool_args(As, Forest) -> - mapfoldl(fun bopt_bool_arg/2, Forest, As). - -bopt_bool_arg({T,_}=R, Forest) when T == x; T == y -> - {gb_trees:get(R, Forest),gb_trees:delete(R, Forest)}; -bopt_bool_arg(Term, Forest) -> - {Term,Forest}. - -bopt_good_args([A|As], Regs) -> - bopt_good_arg(A, Regs), - bopt_good_args(As, Regs); -bopt_good_args([], _) -> ok. - -bopt_good_arg({x,_}=X, Regs) -> - case gb_trees:get(X, Regs) of - any -> ok; - _Other -> - %%io:format("not any: ~p: ~p\n", [X,_Other]), - exit(bad_contents) - end; -bopt_good_arg(_, _) -> ok. - -bif_to_test(_, N, As) -> - bif_to_test(N, As). - -bif_to_test(internal_is_record, [_,_,_]=As) -> - {test,internal_is_record,fail,As}; -bif_to_test('=:=', As) -> {test,is_eq_exact,fail,As}; -bif_to_test('=/=', As) -> {test,is_ne_exact,fail,As}; -bif_to_test('==', As) -> {test,is_eq,fail,As}; -bif_to_test('/=', As) -> {test,is_ne,fail,As}; -bif_to_test('=<', [L,R]) -> {test,is_ge,fail,[R,L]}; -bif_to_test('>=', As) -> {test,is_ge,fail,As}; -bif_to_test('>', [L,R]) -> {test,is_lt,fail,[R,L]}; -bif_to_test('<', As) -> {test,is_lt,fail,As}; -bif_to_test(Name, [_]=As) -> - case erl_internal:new_type_test(Name, 1) of - false -> exit({bif_to_test,Name,As,failed}); - true -> {test,Name,fail,As} - end. - -make_and_list([{'and',As}|Is]) -> - make_and_list(As++Is); -make_and_list([I|Is]) -> - [I|make_and_list(Is)]; -make_and_list([]) -> []. - -make_or_list([{'or',As}|Is]) -> - make_or_list(As++Is); -make_or_list([I|Is]) -> - [I|make_or_list(Is)]; -make_or_list([]) -> []. - -%% Code generation for a boolean tree. - -bopt_cg({'not',Arg}, Fail, Acc, St) -> - I = bopt_cg_not(Arg), - bopt_cg(I, Fail, Acc, St); -bopt_cg({'and',As}, Fail, Acc, St) -> - bopt_cg_and(As, Fail, Acc, St); -bopt_cg({'or',As}, Fail, Acc, St0) -> - {Succ,St} = new_label(St0), - bopt_cg_or(As, Succ, Fail, Acc, St); -bopt_cg({test,is_tuple_element,fail,[Tmp,Tuple,RecordTag]}, Fail, Acc, St) -> - {[{test,is_eq_exact,{f,Fail},[Tmp,RecordTag]}, - {get_tuple_element,Tuple,0,Tmp}|Acc],St}; -bopt_cg({inverted_test,is_tuple_element,fail,[Tmp,Tuple,RecordTag]}, Fail, Acc, St) -> - {[{test,is_ne_exact,{f,Fail},[Tmp,RecordTag]}, - {get_tuple_element,Tuple,0,Tmp}|Acc],St}; -bopt_cg({test,N,fail,As}, Fail, Acc, St) -> - Test = {test,N,{f,Fail},As}, - {[Test|Acc],St}; -bopt_cg({inverted_test,N,fail,As}, Fail, Acc, St0) -> - {Lbl,St} = new_label(St0), - {[{label,Lbl},{jump,{f,Fail}},{test,N,{f,Lbl},As}|Acc],St}; -bopt_cg({protected,_,Bl0,{_,_,_}}, Fail, Acc, St0) -> - {Bl,St} = bopt_block_1(Bl0, Fail, St0), - {Bl++Acc,St}; -bopt_cg([_|_]=And, Fail, Acc, St) -> - bopt_cg_and(And, Fail, Acc, St). - -bopt_cg_not({'and',As0}) -> - As = [bopt_cg_not(A) || A <- As0], - {'or',As}; -bopt_cg_not({'or',As0}) -> - As = [bopt_cg_not(A) || A <- As0], - {'and',As}; -bopt_cg_not({test,Test,Fail,As}) -> - {inverted_test,Test,Fail,As}. - -bopt_cg_and([{atom,false}|_], Fail, _, St) -> - {[{jump,{f,Fail}}],St}; -bopt_cg_and([{atom,true}|Is], Fail, Acc, St) -> - bopt_cg_and(Is, Fail, Acc, St); -bopt_cg_and([I|Is], Fail, Acc0, St0) -> - {Acc,St} = bopt_cg(I, Fail, Acc0, St0), - bopt_cg_and(Is, Fail, Acc, St); -bopt_cg_and([], _, Acc, St) -> {Acc,St}. - -bopt_cg_or([I], Succ, Fail, Acc0, St0) -> - {Acc,St} = bopt_cg(I, Fail, Acc0, St0), - {[{label,Succ}|Acc],St}; -bopt_cg_or([I|Is], Succ, Fail, Acc0, St0) -> - {Lbl,St1} = new_label(St0), - {Acc,St} = bopt_cg(I, Lbl, Acc0, St1), - bopt_cg_or(Is, Succ, Fail, [{label,Lbl},{jump,{f,Succ}}|Acc], St). - -new_label(#st{next=LabelNum}=St) when is_integer(LabelNum) -> - {LabelNum,St#st{next=LabelNum+1}}. - -free_variables(Is) -> - E = gb_sets:empty(), - free_vars_1(Is, E, E). - -free_vars_1([{set,[Dst],As,{bif,_,_}}|Is], F0, N0) -> - F = gb_sets:union(F0, gb_sets:difference(var_list(As), N0)), - N = gb_sets:union(N0, var_list([Dst])), - free_vars_1(Is, F, N); -free_vars_1([{protected,_,Pa,_}|Is], F, N) -> - free_vars_1(Pa++Is, F, N); -free_vars_1([], F, _) -> - gb_trees:from_orddict([{K,any} || K <- gb_sets:to_list(F)]). - -var_list(Is) -> - var_list_1(Is, gb_sets:empty()). - -var_list_1([{x,_}=X|Is], D) -> - var_list_1(Is, gb_sets:add(X, D)); -var_list_1([_|Is], D) -> - var_list_1(Is, D); -var_list_1([], D) -> D. - -%%% -%%% Convert a block to Static Single Assignment (SSA) form. -%%% - --record(ssa, - {live, - sub}). - -ssa_block(Is0) -> - Next = ssa_first_free(Is0, 0), - {Is,_} = ssa_block_1(Is0, #ssa{live=Next,sub=gb_trees:empty()}, []), - Is. - -ssa_block_1([{protected,[_],Pa0,Pb}|Is], Sub0, Acc) -> - {Pa,Sub} = ssa_block_1(Pa0, Sub0, []), - Dst = ssa_last_target(Pa), - ssa_block_1(Is, Sub, [{protected,[Dst],Pa,Pb}|Acc]); -ssa_block_1([{set,[Dst],As,Bif}|Is], Sub0, Acc0) -> - Sub1 = ssa_in_use_list(As, Sub0), - Sub = ssa_assign(Dst, Sub1), - Acc = [{set,[ssa_sub(Dst, Sub)],ssa_sub_list(As, Sub0),Bif}|Acc0], - ssa_block_1(Is, Sub, Acc); -ssa_block_1([], Sub, Acc) -> {reverse(Acc),Sub}. - -ssa_in_use_list(As, Sub) -> - foldl(fun ssa_in_use/2, Sub, As). - -ssa_in_use({x,_}=R, #ssa{sub=Sub0}=Ssa) -> - case gb_trees:is_defined(R, Sub0) of - true -> Ssa; - false -> - Sub = gb_trees:insert(R, R, Sub0), - Ssa#ssa{sub=Sub} - end; -ssa_in_use(_, Ssa) -> Ssa. - -ssa_assign({x,_}=R, #ssa{sub=Sub0}=Ssa0) -> - case gb_trees:is_defined(R, Sub0) of - false -> - Sub = gb_trees:insert(R, R, Sub0), - Ssa0#ssa{sub=Sub}; - true -> - {NewReg,Ssa} = ssa_new_reg(Ssa0), - Sub1 = gb_trees:update(R, NewReg, Sub0), - Sub = gb_trees:insert(NewReg, NewReg, Sub1), - Ssa#ssa{sub=Sub} - end; -ssa_assign(_, Ssa) -> Ssa. - -ssa_sub_list(List, Sub) -> - [ssa_sub(E, Sub) || E <- List]. - -ssa_sub(R0, #ssa{sub=Sub}) -> - case gb_trees:lookup(R0, Sub) of - none -> R0; - {value,R} -> R - end. - -ssa_new_reg(#ssa{live=Reg}=Ssa) -> - {{x,Reg},Ssa#ssa{live=Reg+1}}. - -ssa_first_free([{protected,Ds,_,_}|Is], Next0) -> - Next = ssa_first_free_list(Ds, Next0), - ssa_first_free(Is, Next); -ssa_first_free([{set,[Dst],As,_}|Is], Next0) -> - Next = ssa_first_free_list([Dst|As], Next0), - ssa_first_free(Is, Next); -ssa_first_free([], Next) -> Next. - -ssa_first_free_list(Regs, Next) -> - foldl(fun({x,R}, N) when R >= N -> R+1; - (_, N) -> N end, Next, Regs). - -ssa_last_target([{set,[Dst],_,_},{'%live',_}]) -> Dst; -ssa_last_target([{set,[Dst],_,_}]) -> Dst; -ssa_last_target([_|Is]) -> ssa_last_target(Is). - -%% index_instructions(FunctionIs) -> GbTree([{Label,Is}]) -%% Index the instruction sequence so that we can quickly -%% look up the instruction following a specific label. - -index_instructions(Is) -> - ii_1(Is, []). - -ii_1([{label,Lbl}|Is0], Acc) -> - Is = lists:dropwhile(fun({label,_}) -> true; - (_) -> false end, Is0), - ii_1(Is0, [{Lbl,Is}|Acc]); -ii_1([_|Is], Acc) -> - ii_1(Is, Acc); -ii_1([], Acc) -> gb_trees:from_orddict(sort(Acc)). - -%% is_killed(Register, [Instruction], State) -> true|false -%% Determine whether a register is killed in the instruction sequence. -%% The state is used to allow us to determine the kill state -%% across branches. - -is_killed(R, Is, St) -> - case is_killed_1(R, Is, St) of - false -> - %%io:format("nk ~p: ~P\n", [R,Is,15]), - false; - true -> true - end. - -is_killed_1(R, [{block,Blk}|Is], St) -> - case is_killed_1(R, Blk, St) of - true -> true; - false -> is_killed_1(R, Is, St) - end; -is_killed_1(R, [{test,_,{f,Fail},As}|Is], St) -> - case not member(R, As) andalso is_reg_killed_at(R, Fail, St) of - false -> false; - true -> is_killed_1(R, Is, St) - end; -is_killed_1(R, [{select_val,R,_,_}|_], _) -> false; -is_killed_1(R, [{select_val,_,Fail,{list,Branches}}|_], St) -> - is_killed_at_all(R, [Fail|Branches], St); -is_killed_1(R, [{jump,{f,F}}|_], St) -> - is_reg_killed_at(R, F, St); -is_killed_1(Reg, Is, _) -> - beam_block:is_killed(Reg, Is). - -is_reg_killed_at(R, Lbl, #st{ll=Ll}=St) -> - Is = gb_trees:get(Lbl, Ll), - is_killed_1(R, Is, St). - -is_killed_at_all(R, [{f,Lbl}|T], St) -> - case is_reg_killed_at(R, Lbl, St) of - false -> false; - true -> is_killed_at_all(R, T, St) - end; -is_killed_at_all(R, [_|T], St) -> - is_killed_at_all(R, T, St); -is_killed_at_all(_, [], _) -> true. - -%% is_not_used(Register, [Instruction], State) -> true|false -%% Determine whether a register is never used in the instruction sequence -%% (it could still referenced by an allocate instruction, meaning that -%% it MUST be initialized). -%% The state is used to allow us to determine the usage state -%% across branches. - -is_not_used(R, Is, St) -> - case is_not_used_1(R, Is, St) of - false -> - %%io:format("used ~p: ~P\n", [R,Is,15]), - false; - true -> true - end. - -is_not_used_1(R, [{block,Blk}|Is], St) -> - case is_not_used_1(R, Blk, St) of - true -> true; - false -> is_not_used_1(R, Is, St) - end; -is_not_used_1(R, [{test,_,{f,Fail},As}|Is], St) -> - case not member(R, As) andalso is_reg_not_used_at(R, Fail, St) of - false -> false; - true -> is_not_used_1(R, Is, St) - end; -is_not_used_1(R, [{select_val,R,_,_}|_], _) -> false; -is_not_used_1(R, [{select_val,_,Fail,{list,Branches}}|_], St) -> - is_used_at_none(R, [Fail|Branches], St); -is_not_used_1(R, [{jump,{f,F}}|_], St) -> - is_reg_not_used_at(R, F, St); -is_not_used_1(Reg, Is, _) -> - beam_block:is_not_used(Reg, Is). - -is_reg_not_used_at(R, Lbl, #st{ll=Ll}=St) -> - Is = gb_trees:get(Lbl, Ll), - is_not_used_1(R, Is, St). - -is_used_at_none(R, [{f,Lbl}|T], St) -> - case is_reg_not_used_at(R, Lbl, St) of - false -> false; - true -> is_used_at_none(R, T, St) - end; -is_used_at_none(R, [_|T], St) -> - is_used_at_none(R, T, St); -is_used_at_none(_, [], _) -> true. |