diff options
Diffstat (limited to 'lib/compiler/src/beam_utils.erl')
| -rw-r--r-- | lib/compiler/src/beam_utils.erl | 1001 |
1 files changed, 733 insertions, 268 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index 249d9395ca..3bb671f034 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2007-2016. All Rights Reserved. +%% Copyright Ericsson AB 2007-2018. 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. @@ -22,18 +22,62 @@ -module(beam_utils). -export([is_killed_block/2,is_killed/3,is_killed_at/3, - is_not_used/3,is_not_used_at/3, - empty_label_index/0,index_label/3,index_labels/1, + is_not_used/3,usage/3, + empty_label_index/0,index_label/3,index_labels/1,replace_labels/4, code_at/2,bif_to_test/3,is_pure_test/1, - live_opt/1,delete_live_annos/1,combine_heap_needs/2, - split_even/1]). + live_opt/1,delete_annos/1,combine_heap_needs/2, + anno_defs/1, + split_even/1 + ]). --import(lists, [member/2,sort/1,reverse/1,splitwith/2]). +-export_type([code_index/0,module_code/0,instruction/0]). + +-import(lists, [flatmap/2,map/2,member/2,sort/1,reverse/1,splitwith/2]). + +-define(is_const(Val), (Val =:= nil orelse + element(1, Val) =:= integer orelse + element(1, Val) =:= float orelse + element(1, Val) =:= atom orelse + element(1, Val) =:= literal)). + +%% instruction() describes all instructions that are used during optimzation +%% (from beam_a to beam_z). +-type instruction() :: atom() | tuple(). + +-type code_index() :: gb_trees:tree(beam_asm:label(), [instruction()]). + +-type int_function() :: {'function',beam_asm:function_name(),arity(), + beam_asm:label(),[instruction()]}. + +-type module_code() :: + {module(),[_],[_],[int_function()],pos_integer()}. + +%% Internal types. +-type fail() :: beam_asm:fail() | 'fail'. +-type test() :: {'test',atom(),fail(),[beam_asm:src()]} | + {'test',atom(),fail(),integer(),list(),beam_asm:reg()}. +-type result_cache() :: gb_trees:tree(beam_asm:label(), 'killed' | 'used'). -record(live, - {bl, %Block check fun. - lbl, %Label to code index. - res}). %Result cache for each label. + {lbl :: code_index(), %Label to code index. + res :: result_cache()}). %Result cache for each label. + +%% usage(Register, [Instruction], State) -> killed|not_used|used. +%% Determine the usage of Register in the instruction sequence. +%% The return value is one of: +%% +%% killed - The register is not used in any way. +%% not_used - The register is referenced only by an allocating instruction +%% (the actual value does not matter). +%% used - The register is used (its value do matter). + +-spec usage(beam_asm:reg(), [instruction()], code_index()) -> + 'killed' | 'not_used' | 'used'. + +usage(R, Is, D) -> + St = #live{lbl=D,res=gb_trees:empty()}, + {Usage,_} = check_liveness(R, Is, St), + Usage. %% is_killed_block(Register, [Instruction]) -> true|false @@ -45,12 +89,18 @@ %% i.e. it is OK to enter the instruction sequence with Register %% containing garbage. -is_killed_block(R, Is) -> - case check_killed_block(R, Is) of - killed -> true; - used -> false; - transparent -> false - end. +-spec is_killed_block(beam_asm:reg(), [instruction()]) -> boolean(). + +is_killed_block({x,X}, [{set,_,_,{alloc,Live,_}}|_]) -> + X >= Live; +is_killed_block(R, [{set,Ds,Ss,_Op}|Is]) -> + not member(R, Ss) andalso (member(R, Ds) orelse is_killed_block(R, Is)); +is_killed_block(R, [{'%anno',{used,Regs}}|Is]) -> + case R of + {x,X} when (Regs bsr X) band 1 =:= 0 -> true; + _ -> is_killed_block(R, Is) + end; +is_killed_block(_, []) -> false. %% is_killed(Register, [Instruction], State) -> true|false %% Determine whether a register is killed by the instruction sequence. @@ -62,21 +112,27 @@ is_killed_block(R, Is) -> %% The state (constructed by index_instructions/1) is used to allow us %% to determine the kill state across branches. +-spec is_killed(beam_asm:reg(), [instruction()], code_index()) -> boolean(). + is_killed(R, Is, D) -> - St = #live{bl=check_killed_block_fun(),lbl=D,res=gb_trees:empty()}, + St = #live{lbl=D,res=gb_trees:empty()}, case check_liveness(R, Is, St) of {killed,_} -> true; - {used,_} -> false + {exit_not_used,_} -> false; + {_,_} -> false end. %% is_killed_at(Reg, Lbl, State) -> true|false %% Determine whether Reg is killed at label Lbl. +-spec is_killed_at(beam_asm:reg(), beam_asm:label(), code_index()) -> boolean(). + is_killed_at(R, Lbl, D) when is_integer(Lbl) -> - St0 = #live{bl=check_killed_block_fun(),lbl=D,res=gb_trees:empty()}, + St0 = #live{lbl=D,res=gb_trees:empty()}, case check_liveness_at(R, Lbl, St0) of {killed,_} -> true; - {used,_} -> false + {exit_not_used,_} -> false; + {_,_} -> false end. %% is_not_used(Register, [Instruction], State) -> true|false @@ -86,43 +142,39 @@ is_killed_at(R, Lbl, D) when is_integer(Lbl) -> %% The state is used to allow us to determine the usage state %% across branches. +-spec is_not_used(beam_asm:reg(), [instruction()], code_index()) -> boolean(). + is_not_used(R, Is, D) -> - St = #live{bl=fun check_used_block/3,lbl=D,res=gb_trees:empty()}, + St = #live{lbl=D,res=gb_trees:empty()}, case check_liveness(R, Is, St) of - {killed,_} -> true; - {used,_} -> false - end. - -%% is_not_used(Register, [Instruction], State) -> true|false -%% Determine whether a register is never used in the instruction sequence -%% (it could still be referenced by an allocate instruction, meaning that -%% it MUST be initialized, but that its value does not matter). -%% The state is used to allow us to determine the usage state -%% across branches. - -is_not_used_at(R, Lbl, D) -> - St = #live{bl=fun check_used_block/3,lbl=D,res=gb_trees:empty()}, - case check_liveness_at(R, Lbl, St) of - {killed,_} -> true; - {used,_} -> false + {used,_} -> false; + {exit_not_used,_} -> true; + {_,_} -> true end. %% index_labels(FunctionIs) -> State %% Index the instruction sequence so that we can quickly %% look up the instruction following a specific label. +-spec index_labels([instruction()]) -> code_index(). + index_labels(Is) -> index_labels_1(Is, []). %% empty_label_index() -> State %% Create an empty label index. +-spec empty_label_index() -> code_index(). + empty_label_index() -> gb_trees:empty(). %% index_label(Label, [Instruction], State) -> State %% Add an index for a label. +-spec index_label(beam_asm:label(), [instruction()], code_index()) -> + code_index(). + index_label(Lbl, Is0, Acc) -> Is = drop_labels(Is0), gb_trees:enter(Lbl, Is, Acc). @@ -131,12 +183,28 @@ index_label(Lbl, Is0, Acc) -> %% code_at(Label, State) -> [I]. %% Retrieve the code at the given label. +-spec code_at(beam_asm:label(), code_index()) -> [instruction()]. + code_at(L, Ll) -> gb_trees:get(L, Ll). +%% replace_labels(FunctionIs, Tail, ReplaceDb, Fallback) -> FunctionIs. +%% Replace all labels in instructions according to the ReplaceDb. +%% If label is not found the Fallback is called with the label to +%% produce a new one. + +-spec replace_labels([instruction()], + [instruction()], + #{beam_asm:label() => beam_asm:label()}, + fun((beam_asm:label()) -> term())) -> [instruction()]. +replace_labels(Is, Acc, D, Fb) -> + replace_labels_1(Is, Acc, D, Fb). + %% bif_to_test(Bif, [Op], Fail) -> {test,Test,Fail,[Op]} %% Convert a BIF to a test. Fail if not possible. +-spec bif_to_test(atom(), list(), fail()) -> test(). + bif_to_test(is_atom, [_]=Ops, Fail) -> {test,is_atom,Fail,Ops}; bif_to_test(is_boolean, [_]=Ops, Fail) -> {test,is_boolean,Fail,Ops}; bif_to_test(is_binary, [_]=Ops, Fail) -> {test,is_binary,Fail,Ops}; @@ -157,10 +225,20 @@ bif_to_test('>', [A,B], Fail) -> {test,is_lt,Fail,[B,A]}; bif_to_test('<', [_,_]=Ops, Fail) -> {test,is_lt,Fail,Ops}; bif_to_test('>=', [_,_]=Ops, Fail) -> {test,is_ge,Fail,Ops}; bif_to_test('==', [A,nil], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('==', [nil,A], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('==', [C,A], Fail) when ?is_const(C) -> + {test,is_eq,Fail,[A,C]}; bif_to_test('==', [_,_]=Ops, Fail) -> {test,is_eq,Fail,Ops}; +bif_to_test('/=', [C,A], Fail) when ?is_const(C) -> + {test,is_ne,Fail,[A,C]}; bif_to_test('/=', [_,_]=Ops, Fail) -> {test,is_ne,Fail,Ops}; bif_to_test('=:=', [A,nil], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('=:=', [nil,A], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('=:=', [C,A], Fail) when ?is_const(C) -> + {test,is_eq_exact,Fail,[A,C]}; bif_to_test('=:=', [_,_]=Ops, Fail) -> {test,is_eq_exact,Fail,Ops}; +bif_to_test('=/=', [C,A], Fail) when ?is_const(C) -> + {test,is_ne_exact,Fail,[A,C]}; bif_to_test('=/=', [_,_]=Ops, Fail) -> {test,is_ne_exact,Fail,Ops}; bif_to_test(is_record, [_,_,_]=Ops, Fail) -> {test,is_record,Fail,Ops}. @@ -169,6 +247,9 @@ bif_to_test(is_record, [_,_,_]=Ops, Fail) -> {test,is_record,Fail,Ops}. %% Return 'true' if the test instruction does not modify any %% registers and/or bit syntax matching state. %% + +-spec is_pure_test(test()) -> boolean(). + is_pure_test({test,is_eq,_,[_,_]}) -> true; is_pure_test({test,is_ne,_,[_,_]}) -> true; is_pure_test({test,is_eq_exact,_,[_,_]}) -> true; @@ -189,9 +270,11 @@ is_pure_test({test,Op,_,Ops}) -> %% Go through the instruction sequence in reverse execution %% order, keep track of liveness and remove 'move' instructions %% whose destination is a register that will not be used. -%% Also insert {'%live',Live,Regs} annotations at the beginning +%% Also insert {used,Regs} annotations at the beginning %% and end of each block. -%% + +-spec live_opt([instruction()]) -> [instruction()]. + live_opt(Is0) -> {[{label,Fail}|_]=Bef,[Fi|Is]} = splitwith(fun({func_info,_,_,_}) -> false; @@ -202,37 +285,59 @@ live_opt(Is0) -> Bef ++ [Fi|live_opt(reverse(Is), 0, D, [])]. -%% delete_live_annos([Instruction]) -> [Instruction]. -%% Delete all live annotations. -%% -delete_live_annos([{block,Bl0}|Is]) -> - case delete_live_annos(Bl0) of - [] -> delete_live_annos(Is); - [_|_]=Bl -> [{block,Bl}|delete_live_annos(Is)] - end; -delete_live_annos([{'%live',_,_}|Is]) -> - delete_live_annos(Is); -delete_live_annos([I|Is]) -> - [I|delete_live_annos(Is)]; -delete_live_annos([]) -> []. - +%% delete_annos([Instruction]) -> [Instruction]. +%% Delete all annotations. + +-spec delete_annos([instruction()]) -> [instruction()]. + +delete_annos([{block,Bl0}|Is]) -> + case delete_annos(Bl0) of + [] -> delete_annos(Is); + [_|_]=Bl -> [{block,Bl}|delete_annos(Is)] + end; +delete_annos([{'%anno',_}|Is]) -> + delete_annos(Is); +delete_annos([I|Is]) -> + [I|delete_annos(Is)]; +delete_annos([]) -> []. + %% combine_heap_needs(HeapNeed1, HeapNeed2) -> HeapNeed %% Combine the heap need for two allocation instructions. -combine_heap_needs({alloc,Alloc1}, {alloc,Alloc2}) -> - {alloc,combine_alloc_lists(Alloc1, Alloc2)}; -combine_heap_needs({alloc,Alloc}, Words) when is_integer(Words) -> - {alloc,combine_alloc_lists(Alloc, [{words,Words}])}; -combine_heap_needs(Words, {alloc,Alloc}) when is_integer(Words) -> - {alloc,combine_alloc_lists(Alloc, [{words,Words}])}; +-type heap_need_tag() :: 'floats' | 'words'. +-type heap_need() :: non_neg_integer() | + {'alloc',[{heap_need_tag(),non_neg_integer()}]}. +-spec combine_heap_needs(heap_need(), heap_need()) -> heap_need(). + combine_heap_needs(H1, H2) when is_integer(H1), is_integer(H2) -> - H1+H2. + H1 + H2; +combine_heap_needs(H1, H2) -> + {alloc,combine_alloc_lists([H1,H2])}. + + +%% anno_defs(Instructions) -> Instructions' +%% Add {def,RegisterBitmap} annotations to the beginning of +%% each block. Iff bit X is set in the the bitmap, it means +%% that {x,X} is defined when the block is entered. + +-spec anno_defs([instruction()]) -> [instruction()]. + +anno_defs(Is0) -> + {Bef,[Fi|Is1]} = + splitwith(fun({func_info,_,_,_}) -> false; + (_) -> true + end, Is0), + {func_info,_,_,Arity} = Fi, + Regs = init_def_regs(Arity), + Is = defs(Is1, Regs, #{}), + Bef ++ [Fi|Is]. %% split_even/1 %% [1,2,3,4,5,6] -> {[1,3,5],[2,4,6]} -split_even(Rs) -> split_even(Rs, [], []). +-spec split_even(list()) -> {list(),list()}. +split_even(Rs) -> split_even(Rs, [], []). %%% %%% Local functions. @@ -240,15 +345,29 @@ split_even(Rs) -> split_even(Rs, [], []). %% check_liveness(Reg, [Instruction], #live{}) -> -%% {killed | used, #live{}} +%% {killed | not_used | used, #live{}} %% Find out whether Reg is used or killed in instruction sequence. -%% 'killed' means that Reg is assigned a new value or killed by an -%% allocation instruction. 'used' means that Reg is used in some way. - -check_liveness(R, [{block,Blk}|Is], #live{bl=BlockCheck}=St0) -> - case BlockCheck(R, Blk, St0) of - {transparent,St} -> check_liveness(R, Is, St); - {Other,_}=Res when is_atom(Other) -> Res +%% +%% killed - Reg is assigned or killed by an allocation instruction. +%% not_used - the value of Reg is not used, but Reg must not be garbage +%% exit_not_used - the value of Reg is not used, but must not be garbage +%% because the stack will be scanned because an +%% exit BIF will raise an exception +%% used - Reg is used + +check_liveness({fr,_}, _, St) -> + %% Conservatively always consider the floating point register used. + {used,St}; +check_liveness(R, [{block,Blk}|Is], St0) -> + case check_liveness_block(R, Blk, St0) of + {transparent,St1} -> + check_liveness(R, Is, St1); + {alloc_used,St1} -> + %% Used by an allocating instruction, but value not referenced. + %% Must check the rest of the instructions. + not_used(check_liveness(R, Is, St1)); + {Other,_}=Res when is_atom(Other) -> + Res end; check_liveness(R, [{label,_}|Is], St) -> check_liveness(R, Is, St); @@ -258,8 +377,14 @@ check_liveness(R, [{test,_,{f,Fail},As}|Is], St0) -> {used,St0}; false -> case check_liveness_at(R, Fail, St0) of - {killed,St} -> check_liveness(R, Is, St); - {_,_}=Other -> Other + {killed,St1} -> + check_liveness(R, Is, St1); + {exit_not_used,St1} -> + not_used(check_liveness(R, Is, St1)); + {not_used,St1} -> + not_used(check_liveness(R, Is, St1)); + {used,_}=Used -> + Used end end; check_liveness(R, [{test,Op,Fail,Live,Ss,Dst}|Is], St) -> @@ -273,12 +398,14 @@ check_liveness(R, [{select,_,_,Fail,Branches}|_], St) -> check_liveness_everywhere(R, [Fail|Branches], St); check_liveness(R, [{jump,{f,F}}|_], St) -> check_liveness_at(R, F, St); -check_liveness(R, [{case_end,Used}|_], St) -> - check_liveness_ret(R, Used, St); +check_liveness(R, [{case_end,Used}|_], St) -> + check_liveness_exit(R, Used, St); +check_liveness(R, [{try_case_end,Used}|_], St) -> + check_liveness_exit(R, Used, St); check_liveness(R, [{badmatch,Used}|_], St) -> - check_liveness_ret(R, Used, St); -check_liveness(_, [if_end|_], St) -> - {killed,St}; + check_liveness_exit(R, Used, St); +check_liveness(R, [if_end|_], St) -> + check_liveness_exit(R, ignore, St); check_liveness(R, [{func_info,_,_,Ar}|_], St) -> case R of {x,X} when X < Ar -> {used,St}; @@ -301,17 +428,27 @@ check_liveness(R, [{bs_init,_,_,none,Ss,Dst}|Is], St) -> check_liveness(R, [{bs_init,_,_,Live,Ss,Dst}|Is], St) -> case R of {x,X} -> - case X < Live orelse member(R, Ss) of - true -> {used,St}; - false -> {killed,St} + case member(R, Ss) of + true -> + {used,St}; + false -> + if + X < Live -> + not_used(check_liveness(R, Is, St)); + true -> + {killed,St} + end end; {y,_} -> case member(R, Ss) of true -> {used,St}; false -> + %% If the exception is taken, the stack may + %% be scanned. Therefore the register is not + %% guaranteed to be killed. if - R =:= Dst -> {killed,St}; - true -> check_liveness(R, Is, St) + R =:= Dst -> {not_used,St}; + true -> not_used(check_liveness(R, Is, St)) end end end; @@ -329,7 +466,7 @@ check_liveness(R, [{call,Live,_}|Is], St) -> case R of {x,X} when X < Live -> {used,St}; {x,_} -> {killed,St}; - {y,_} -> check_liveness(R, Is, St) + {y,_} -> not_used(check_liveness(R, Is, St)) end; check_liveness(R, [{call_ext,Live,_}=I|Is], St) -> case R of @@ -340,55 +477,32 @@ check_liveness(R, [{call_ext,Live,_}=I|Is], St) -> {y,_} -> case beam_jump:is_exit_instruction(I) of false -> - check_liveness(R, Is, St); + not_used(check_liveness(R, Is, St)); true -> %% We must make sure we don't check beyond this %% instruction or we will fall through into random %% unrelated code and get stuck in a loop. - {killed,St} + {exit_not_used,St} end end; check_liveness(R, [{call_fun,Live}|Is], St) -> case R of {x,X} when X =< Live -> {used,St}; {x,_} -> {killed,St}; - {y,_} -> check_liveness(R, Is, St) + {y,_} -> not_used(check_liveness(R, Is, St)) end; check_liveness(R, [{apply,Args}|Is], St) -> case R of {x,X} when X < Args+2 -> {used,St}; {x,_} -> {killed,St}; - {y,_} -> check_liveness(R, Is, St) - end; -check_liveness(R, [{bif,Op,{f,Fail},Ss,D}|Is], St0) -> - case check_liveness_fail(R, Op, Ss, Fail, St0) of - {killed,St} = Killed -> - case member(R, Ss) of - true -> {used,St}; - false when R =:= D -> Killed; - false -> check_liveness(R, Is, St) - end; - Other -> - Other - end; -check_liveness(R, [{gc_bif,Op,{f,Fail},Live,Ss,D}|Is], St0) -> - case R of - {x,X} when X >= Live -> - {killed,St0}; - {x,_} -> - {used,St0}; - _ -> - case check_liveness_fail(R, Op, Ss, Fail, St0) of - {killed,St}=Killed -> - case member(R, Ss) of - true -> {used,St}; - false when R =:= D -> Killed; - false -> check_liveness(R, Is, St) - end; - Other -> - Other - end + {y,_} -> not_used(check_liveness(R, Is, St)) end; +check_liveness(R, [{bif,Op,Fail,Ss,D}|Is], St) -> + Set = {set,[D],Ss,{bif,Op,Fail}}, + check_liveness(R, [{block,[Set]}|Is], St); +check_liveness(R, [{gc_bif,Op,{f,Fail},Live,Ss,D}|Is], St) -> + Set = {set,[D],Ss,{alloc,Live,{gc_bif,Op,Fail}}}, + check_liveness(R, [{block,[Set]}|Is], St); check_liveness(R, [{bs_put,{f,0},_,Ss}|Is], St) -> case member(R, Ss) of true -> {used,St}; @@ -414,18 +528,14 @@ check_liveness(R, [{make_fun2,_,_,_,NumFree}|Is], St) -> case R of {x,X} when X < NumFree -> {used,St}; {x,_} -> {killed,St}; - _ -> check_liveness(R, Is, St) + {y,_} -> not_used(check_liveness(R, Is, St)) end; -check_liveness({x,_}=R, [{'catch',_,_}|Is], St) -> - %% All x registers will be killed if an exception occurs. - %% Therefore we only need to check the liveness for the - %% instructions following the catch instruction. - check_liveness(R, Is, St); -check_liveness({x,_}=R, [{'try',_,_}|Is], St) -> - %% All x registers will be killed if an exception occurs. - %% Therefore we only need to check the liveness for the - %% instructions inside the 'try' block. - check_liveness(R, Is, St); +check_liveness(R, [{'catch'=Op,Y,Fail}|Is], St) -> + Set = {set,[Y],[],{try_catch,Op,Fail}}, + check_liveness(R, [{block,[Set]}|Is], St); +check_liveness(R, [{'try'=Op,Y,Fail}|Is], St) -> + Set = {set,[Y],[],{try_catch,Op,Fail}}, + check_liveness(R, [{block,[Set]}|Is], St); check_liveness(R, [{try_end,Y}|Is], St) -> case R of Y -> @@ -483,40 +593,58 @@ check_liveness(R, [{get_map_elements,{f,Fail},S,{list,L}}|Is], St0) -> Other end end; -check_liveness(R, [{put_map,{f,_},_,Src,_D,Live,{list,_}}|_], St0) -> - case R of - Src -> - {used,St0}; - {x,X} when X < Live -> - {used,St0}; - {x,_} -> - {killed,St0}; - {y,_} -> - %% Conservatively mark it as used. - {used,St0} - end; +check_liveness(R, [{put_map,F,Op,S,D,Live,{list,Puts}}|Is], St) -> + Set = {set,[D],[S|Puts],{alloc,Live,{put_map,Op,F}}}, + check_liveness(R, [{block,[Set]}||Is], St); +check_liveness(R, [{put_tuple,Ar,D}|Is], St) -> + Set = {set,[D],[],{put_tuple,Ar}}, + check_liveness(R, [{block,[Set]}||Is], St); +check_liveness(R, [{put_list,S1,S2,D}|Is], St) -> + Set = {set,[D],[S1,S2],put_list}, + check_liveness(R, [{block,[Set]}||Is], St); check_liveness(R, [{test_heap,N,Live}|Is], St) -> I = {block,[{set,[],[],{alloc,Live,{nozero,nostack,N,[]}}}]}, check_liveness(R, [I|Is], St); check_liveness(R, [{allocate_zero,N,Live}|Is], St) -> I = {block,[{set,[],[],{alloc,Live,{zero,N,0,[]}}}]}, check_liveness(R, [I|Is], St); -check_liveness(R, [{get_list,S,D1,D2}|Is], St) -> - I = {block,[{set,[D1,D2],[S],get_list}]}, +check_liveness(R, [{get_hd,S,D}|Is], St) -> + I = {block,[{set,[D],[S],get_hd}]}, check_liveness(R, [I|Is], St); +check_liveness(R, [{get_tl,S,D}|Is], St) -> + I = {block,[{set,[D],[S],get_tl}]}, + check_liveness(R, [I|Is], St); +check_liveness(R, [remove_message|Is], St) -> + check_liveness(R, Is, St); +check_liveness({x,X}, [build_stacktrace|_], St) when X > 0 -> + {killed,St}; +check_liveness(R, [{recv_mark,_}|Is], St) -> + check_liveness(R, Is, St); +check_liveness(R, [{recv_set,_}|Is], St) -> + check_liveness(R, Is, St); +check_liveness(R, [{'%',_}|Is], St) -> + check_liveness(R, Is, St); check_liveness(_R, Is, St) when is_list(Is) -> %% Not implemented. Conservatively assume that the register is used. {used,St}. - -check_liveness_everywhere(R, [{f,Lbl}|T], St0) -> - case check_liveness_at(R, Lbl, St0) of - {killed,St} -> check_liveness_everywhere(R, T, St); - {_,_}=Other -> Other + +check_liveness_everywhere(R, Lbls, St0) -> + check_liveness_everywhere_1(R, Lbls, killed, St0). + +check_liveness_everywhere_1(R, [{f,Lbl}|T], Res0, St0) -> + {Res1,St} = check_liveness_at(R, Lbl, St0), + Res = case Res1 of + killed -> Res0; + _ -> Res1 + end, + case Res of + used -> {used,St}; + _ -> check_liveness_everywhere_1(R, T, Res, St) end; -check_liveness_everywhere(R, [_|T], St) -> - check_liveness_everywhere(R, T, St); -check_liveness_everywhere(_, [], St) -> - {killed,St}. +check_liveness_everywhere_1(R, [_|T], Res, St) -> + check_liveness_everywhere_1(R, T, Res, St); +check_liveness_everywhere_1(_, [], Res, St) -> + {Res,St}. check_liveness_at(R, Lbl, #live{lbl=Ll,res=ResMemorized}=St0) -> case gb_trees:lookup(Lbl, ResMemorized) of @@ -530,102 +658,116 @@ check_liveness_at(R, Lbl, #live{lbl=Ll,res=ResMemorized}=St0) -> {Res,St#live{res=gb_trees:insert(Lbl, Res, St#live.res)}} end. -check_liveness_ret(R, R, St) -> {used,St}; -check_liveness_ret(_, _, St) -> {killed,St}. +not_used({used,_}=Res) -> Res; +not_used({_,St}) -> {not_used,St}. -check_liveness_fail(_, _, _, 0, St) -> - {killed,St}; -check_liveness_fail(R, Op, Args, Fail, St) -> - Arity = length(Args), - case erl_internal:comp_op(Op, Arity) orelse - erl_internal:new_type_test(Op, Arity) of - true -> {killed,St}; - false -> check_liveness_at(R, Fail, St) - end. +check_liveness_exit(R, R, St) -> {used,St}; +check_liveness_exit({x,_}, _, St) -> {killed,St}; +check_liveness_exit({y,_}, _, St) -> {exit_not_used,St}. -%% check_killed_block(Reg, [Instruction], State) -> killed | transparent | used +%% check_liveness_block(Reg, [Instruction], State) -> +%% {killed | not_used | used | alloc_used | transparent,State'} %% Finds out how Reg is used in the instruction sequence inside a block. %% Returns one of: -%% killed - Reg is assigned a new value or killed by an allocation instruction -%% transparent - Reg is neither used nor killed -%% used - Reg is used or referenced by an allocation instruction. -%% -%% (Unknown instructions will cause an exception.) - -check_killed_block_fun() -> - fun(R, Is, St) -> {check_killed_block(R, Is),St} end. - -check_killed_block({x,X}, [{set,_,_,{alloc,Live,_}}|_]) -> - if - X >= Live -> killed; - true -> used - end; -check_killed_block(R, [{set,Ds,Ss,_Op}|Is]) -> - case member(R, Ss) of - true -> used; - false -> - case member(R, Ds) of - true -> killed; - false -> check_killed_block(R, Is) - end - end; -check_killed_block(R, [{'%live',_,Regs}|Is]) -> - case R of - {x,X} when (Regs bsr X) band 1 =:= 0 -> killed; - _ -> check_killed_block(R, Is) - end; -check_killed_block(_, []) -> transparent. - -%% check_used_block(Reg, [Instruction], State) -> killed | transparent | used -%% Finds out how Reg is used in the instruction sequence inside a block. -%% Returns one of: -%% killed - Reg is assigned a new value or killed by an allocation instruction +%% killed - Reg is assigned a new value or killed by an +%% allocation instruction +%% not_used - The value is not used, but the register is referenced +%% e.g. by an allocation instruction %% transparent - Reg is neither used nor killed +%% alloc_used - Used only in an allocate instruction %% used - Reg is explicitly used by an instruction %% -%% '%live' annotations are not allowed. +%% Annotations are not allowed. %% %% (Unknown instructions will cause an exception.) -check_used_block({x,X}=R, [{set,Ds,Ss,{alloc,Live,Op}}|Is], St) -> +check_liveness_block({x,X}=R, [{set,Ds,Ss,{alloc,Live,Op}}|Is], St0) -> if - X >= Live -> {killed,St}; - true -> check_used_block_1(R, Ss, Ds, Op, Is, St) + X >= Live -> + {killed,St0}; + true -> + case check_liveness_block_1(R, Ss, Ds, Op, Is, St0) of + {transparent,St} -> {alloc_used,St}; + {_,_}=Res -> not_used(Res) + end + end; +check_liveness_block({y,_}=R, [{set,Ds,Ss,{alloc,_Live,Op}}|Is], St0) -> + case check_liveness_block_1(R, Ss, Ds, Op, Is, St0) of + {transparent,St} -> {alloc_used,St}; + {_,_}=Res -> not_used(Res) end; -check_used_block(R, [{set,Ds,Ss,Op}|Is], St) -> - check_used_block_1(R, Ss, Ds, Op, Is, St); -check_used_block(_, [], St) -> {transparent,St}. +check_liveness_block({y,_}=R, [{set,Ds,Ss,{try_catch,_,Op}}|Is], St0) -> + case Ds of + [R] -> + {killed,St0}; + _ -> + case check_liveness_block_1(R, Ss, Ds, Op, Is, St0) of + {exit_not_used,St} -> + {used,St}; + {transparent,St} -> + %% Conservatively assumed that it is used. + {used,St}; + {_,_}=Res -> + Res + end + end; +check_liveness_block(R, [{set,Ds,Ss,Op}|Is], St) -> + check_liveness_block_1(R, Ss, Ds, Op, Is, St); +check_liveness_block(_, [], St) -> {transparent,St}. -check_used_block_1(R, Ss, Ds, Op, Is, St0) -> +check_liveness_block_1(R, Ss, Ds, Op, Is, St0) -> case member(R, Ss) of true -> {used,St0}; false -> - case is_reg_used_at(R, Op, St0) of - {true,St} -> - {used,St}; - {false,St} -> + case check_liveness_block_2(R, Op, Ss, St0) of + {killed,St} -> case member(R, Ds) of true -> {killed,St}; - false -> check_used_block(R, Is, St) - end + false -> check_liveness_block(R, Is, St) + end; + {exit_not_used,St} -> + case member(R, Ds) of + true -> {exit_not_used,St}; + false -> check_liveness_block(R, Is, St) + end; + {not_used,St} -> + not_used(case member(R, Ds) of + true -> {killed,St}; + false -> check_liveness_block(R, Is, St) + end); + {used,St} -> + {used,St} end end. -is_reg_used_at(R, {gc_bif,_,{f,Lbl}}, St) -> - is_reg_used_at_1(R, Lbl, St); -is_reg_used_at(R, {bif,_,{f,Lbl}}, St) -> - is_reg_used_at_1(R, Lbl, St); -is_reg_used_at(_, _, St) -> - {false,St}. +check_liveness_block_2(R, {gc_bif,Op,{f,Lbl}}, Ss, St) -> + check_liveness_block_3(R, Lbl, {Op,length(Ss)}, St); +check_liveness_block_2(R, {bif,Op,{f,Lbl}}, Ss, St) -> + Arity = length(Ss), + case erl_internal:comp_op(Op, Arity) orelse + erl_internal:new_type_test(Op, Arity) of + true -> + {killed,St}; + false -> + check_liveness_block_3(R, Lbl, {Op,length(Ss)}, St) + end; +check_liveness_block_2(R, {put_map,_Op,{f,Lbl}}, _Ss, St) -> + check_liveness_block_3(R, Lbl, {unsafe,0}, St); +check_liveness_block_2(_, _, _, St) -> + {killed,St}. -is_reg_used_at_1(_, 0, St) -> - {false,St}; -is_reg_used_at_1(R, Lbl, St0) -> - case check_liveness_at(R, Lbl, St0) of - {killed,St} -> {false,St}; - {used,St} -> {true,St} - end. +check_liveness_block_3({x,_}, 0, _FA, St) -> + {killed,St}; +check_liveness_block_3({y,_}, 0, {F,A}, St) -> + %% If the exception is thrown, the stack may be scanned, + %% thus implicitly using the y register. + case erl_bifs:is_safe(erlang, F, A) of + true -> {killed,St}; + false -> {used,St} + end; +check_liveness_block_3(R, Lbl, _FA, St0) -> + check_liveness_at(R, Lbl, St0). index_labels_1([{label,Lbl}|Is0], Acc) -> Is = drop_labels(Is0), @@ -637,22 +779,74 @@ index_labels_1([], Acc) -> gb_trees:from_orddict(sort(Acc)). drop_labels([{label,_}|Is]) -> drop_labels(Is); drop_labels(Is) -> Is. -%% Help functions for combine_heap_needs. -combine_alloc_lists(Al1, Al2) -> - combine_alloc_lists_1(sort(Al1++Al2)). +replace_labels_1([{test,Test,{f,Lbl},Ops}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{test,Test,{f,label(Lbl, D, Fb)},Ops}|Acc], D, Fb); +replace_labels_1([{test,Test,{f,Lbl},Live,Ops,Dst}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{test,Test,{f,label(Lbl, D, Fb)},Live,Ops,Dst}|Acc], D, Fb); +replace_labels_1([{select,I,R,{f,Fail0},Vls0}|Is], Acc, D, Fb) -> + Vls = map(fun ({f,L}) -> {f,label(L, D, Fb)}; + (Other) -> Other + end, Vls0), + Fail = label(Fail0, D, Fb), + replace_labels_1(Is, [{select,I,R,{f,Fail},Vls}|Acc], D, Fb); +replace_labels_1([{'try',R,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{'try',R,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{'catch',R,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{'catch',R,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{jump,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{jump,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{loop_rec,{f,Lbl},R}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{loop_rec,{f,label(Lbl, D, Fb)},R}|Acc], D, Fb); +replace_labels_1([{loop_rec_end,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{loop_rec_end,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{wait,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{wait,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{wait_timeout,{f,Lbl},To}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{wait_timeout,{f,label(Lbl, D, Fb)},To}|Acc], D, Fb); +replace_labels_1([{recv_mark=Op,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{Op,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{recv_set=Op,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{Op,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{bif,Name,{f,Lbl},As,R}|Is], Acc, D, Fb) when Lbl =/= 0 -> + replace_labels_1(Is, [{bif,Name,{f,label(Lbl, D, Fb)},As,R}|Acc], D, Fb); +replace_labels_1([{gc_bif,Name,{f,Lbl},Live,As,R}|Is], Acc, D, Fb) when Lbl =/= 0 -> + replace_labels_1(Is, [{gc_bif,Name,{f,label(Lbl, D, Fb)},Live,As,R}|Acc], D, Fb); +replace_labels_1([{call,Ar,{f,Lbl}}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{call,Ar,{f,label(Lbl, D, Fb)}}|Acc], D, Fb); +replace_labels_1([{make_fun2,{f,Lbl},U1,U2,U3}|Is], Acc, D, Fb) -> + replace_labels_1(Is, [{make_fun2,{f,label(Lbl, D, Fb)},U1,U2,U3}|Acc], D, Fb); +replace_labels_1([{bs_init,{f,Lbl},Info,Live,Ss,Dst}|Is], Acc, D, Fb) when Lbl =/= 0 -> + replace_labels_1(Is, [{bs_init,{f,label(Lbl, D, Fb)},Info,Live,Ss,Dst}|Acc], D, Fb); +replace_labels_1([{bs_put,{f,Lbl},Info,Ss}|Is], Acc, D, Fb) when Lbl =/= 0 -> + replace_labels_1(Is, [{bs_put,{f,label(Lbl, D, Fb)},Info,Ss}|Acc], D, Fb); +replace_labels_1([{put_map=I,{f,Lbl},Op,Src,Dst,Live,List}|Is], Acc, D, Fb) + when Lbl =/= 0 -> + replace_labels_1(Is, [{I,{f,label(Lbl, D, Fb)},Op,Src,Dst,Live,List}|Acc], D, Fb); +replace_labels_1([{get_map_elements=I,{f,Lbl},Src,List}|Is], Acc, D, Fb) when Lbl =/= 0 -> + replace_labels_1(Is, [{I,{f,label(Lbl, D, Fb)},Src,List}|Acc], D, Fb); +replace_labels_1([I|Is], Acc, D, Fb) -> + replace_labels_1(Is, [I|Acc], D, Fb); +replace_labels_1([], Acc, _, _) -> Acc. + +label(Old, D, Fb) -> + case D of + #{Old := New} -> New; + _ -> Fb(Old) + end. + +%% Help function for combine_heap_needs. -combine_alloc_lists_1([{words,W1},{words,W2}|T]) - when is_integer(W1), is_integer(W2) -> - [{words,W1+W2}|combine_alloc_lists_1(T)]; -combine_alloc_lists_1([{floats,F1},{floats,F2}|T]) - when is_integer(F1), is_integer(F2) -> - [{floats,F1+F2}|combine_alloc_lists_1(T)]; -combine_alloc_lists_1([{words,_}=W|T]) -> - [W|combine_alloc_lists_1(T)]; -combine_alloc_lists_1([{floats,_}=F|T]) -> - [F|combine_alloc_lists_1(T)]; -combine_alloc_lists_1([]) -> []. +combine_alloc_lists(Al0) -> + Al1 = flatmap(fun(Words) when is_integer(Words) -> + [{words,Words}]; + ({alloc,List}) -> + List + end, Al0), + Al2 = sofs:relation(Al1), + Al3 = sofs:relation_to_family(Al2), + Al4 = sofs:to_external(Al3), + [{Tag,lists:sum(L)} || {Tag,L} <- Al4]. %% live_opt/4. @@ -691,10 +885,14 @@ live_opt([{test,bs_start_match2,Fail,Live,[Src,_],_}=I|Is], _, D, Acc) -> %% Other instructions. live_opt([{block,Bl0}|Is], Regs0, D, Acc) -> - Live0 = {'%live',live_regs(Regs0),Regs0}, + Live0 = make_anno({used,Regs0}), {Bl,Regs} = live_opt_block(reverse(Bl0), Regs0, D, [Live0]), - Live = {'%live',live_regs(Regs),Regs}, + Live = make_anno({used,Regs}), live_opt(Is, Regs, D, [{block,[Live|Bl]}|Acc]); +live_opt([build_stacktrace=I|Is], _, D, Acc) -> + live_opt(Is, live_call(1), D, [I|Acc]); +live_opt([raw_raise=I|Is], _, D, Acc) -> + live_opt(Is, live_call(3), D, [I|Acc]); live_opt([{label,L}=I|Is], Regs, D0, Acc) -> D = gb_trees:insert(L, Regs, D0), live_opt(Is, Regs, D, [I|Acc]); @@ -736,12 +934,19 @@ live_opt([{test,_,Fail,Live,Ss,_}=I|Is], _, D, Acc) -> Regs1 = x_live(Ss, Regs0), Regs = live_join_label(Fail, D, Regs1), live_opt(Is, Regs, D, [I|Acc]); -live_opt([{select,_,Src,Fail,List}=I|Is], Regs0, D, Acc) -> +live_opt([{select,_,Src,Fail,List}=I|Is], _, D, Acc) -> + Regs0 = 0, Regs1 = x_live([Src], Regs0), Regs = live_join_labels([Fail|List], D, Regs1), live_opt(Is, Regs, D, [I|Acc]); -live_opt([{try_case,_}=I|Is], _, D, Acc) -> - live_opt(Is, live_call(1), D, [I|Acc]); +live_opt([{try_case,Y}=I|Is], Regs0, D, Acc) -> + Regs = live_call(1), + case Regs0 of + 0 -> + live_opt(Is, Regs, D, [{try_end,Y}|Acc]); + _ -> + live_opt(Is, live_call(1), D, [I|Acc]) + end; live_opt([{loop_rec,_Fail,_Dst}=I|Is], _, D, Acc) -> live_opt(Is, 0, D, [I|Acc]); live_opt([timeout=I|Is], _, D, Acc) -> @@ -753,6 +958,25 @@ live_opt([{get_map_elements,Fail,Src,{list,List}}=I|Is], Regs0, D, Acc) -> Regs1 = x_live([Src|Ss], x_dead(Ds, Regs0)), Regs = live_join_label(Fail, D, Regs1), live_opt(Is, Regs, D, [I|Acc]); +live_opt([{gc_bif,N,F,R,As,Dst}=I|Is], Regs0, D, Acc) -> + Bl = [{set,[Dst],As,{alloc,R,{gc_bif,N,F}}}], + {_,Regs} = live_opt_block(Bl, Regs0, D, []), + live_opt(Is, Regs, D, [I|Acc]); +live_opt([{bif,N,F,As,Dst}=I|Is], Regs0, D, Acc) -> + Bl = [{set,[Dst],As,{bif,N,F}}], + {_,Regs} = live_opt_block(Bl, Regs0, D, []), + live_opt(Is, Regs, D, [I|Acc]); +live_opt([{get_tuple_element,Src,Idx,Dst}=I|Is], Regs0, D, Acc) -> + Bl = [{set,[Dst],[Src],{get_tuple_element,Idx}}], + {_,Regs} = live_opt_block(Bl, Regs0, D, []), + live_opt(Is, Regs, D, [I|Acc]); +live_opt([{move,Src,Dst}=I|Is], Regs0, D, Acc) -> + Regs = x_live([Src], x_dead([Dst], Regs0)), + live_opt(Is, Regs, D, [I|Acc]); +live_opt([{put_map,F,Op,S,Dst,R,{list,Puts}}=I|Is], Regs0, D, Acc) -> + Bl = [{set,[Dst],[S|Puts],{alloc,R,{put_map,Op,F}}}], + {_,Regs} = live_opt_block(Bl, Regs0, D, []), + live_opt(Is, Regs, D, [I|Acc]); %% Transparent instructions - they neither use nor modify x registers. live_opt([{deallocate,_}=I|Is], Regs, D, Acc) -> @@ -769,6 +993,10 @@ live_opt([{wait_timeout,_,{Tag,_}}=I|Is], Regs, D, Acc) when Tag =/= x -> live_opt(Is, Regs, D, [I|Acc]); live_opt([{line,_}=I|Is], Regs, D, Acc) -> live_opt(Is, Regs, D, [I|Acc]); +live_opt([{'catch',_,_}=I|Is], Regs, D, Acc) -> + live_opt(Is, Regs, D, [I|Acc]); +live_opt([{'try',_,_}=I|Is], Regs, D, Acc) -> + live_opt(Is, Regs, D, [I|Acc]); %% The following instructions can occur if the "compilation" has been %% started from a .S file using the 'from_asm' option. @@ -783,37 +1011,53 @@ live_opt([{recv_mark,_}=I|Is], Regs, D, Acc) -> live_opt([], _, _, Acc) -> Acc. -live_opt_block([{set,Ds,Ss,Op}=I0|Is], Regs0, D, Acc) -> - Regs1 = x_live(Ss, x_dead(Ds, Regs0)), - {I,Regs} = case Op of - {alloc,Live0,Alloc} -> - %% The life-time analysis used by the code generator - %% is sometimes too conservative, so it may be - %% possible to lower the number of live registers - %% based on the exact liveness information. - %% The main benefit is that more optimizations that - %% depend on liveness information (such as the - %% beam_bool and beam_dead passes) may be applied. - Live = live_regs(Regs1), - true = Live =< Live0, %Assertion. - I1 = {set,Ds,Ss,{alloc,Live,Alloc}}, - {I1,live_call(Live)}; - _ -> - {I0,Regs1} - end, - case Ds of - [{x,X}] -> - case (not is_live(X, Regs0)) andalso Op =:= move of - true -> - live_opt_block(Is, Regs0, D, Acc); - false -> - live_opt_block(Is, Regs, D, [I|Acc]) - end; - _ -> - live_opt_block(Is, Regs, D, [I|Acc]) +live_opt_block([{set,[{x,X}]=Ds,Ss,move}=I|Is], Regs0, D, Acc) -> + Regs = x_live(Ss, x_dead(Ds, Regs0)), + case is_live(X, Regs0) of + true -> + live_opt_block(Is, Regs, D, [I|Acc]); + false -> + %% Useless move, will never be used. + live_opt_block(Is, Regs, D, Acc) end; +live_opt_block([{set,Ds,Ss,{alloc,Live0,AllocOp}}|Is], Regs0, D, Acc) -> + %% Calculate liveness from the point of view of the GC. + %% There will never be a GC if the instruction fails, so we should + %% ignore the failure branch. + GcRegs1 = x_dead(Ds, Regs0), + GcRegs = x_live(Ss, GcRegs1), + Live = live_regs(GcRegs), + + %% The life-time analysis used by the code generator is sometimes too + %% conservative, so it may be possible to lower the number of live + %% registers based on the exact liveness information. The main benefit is + %% that more optimizations that depend on liveness information (such as the + %% beam_dead pass) may be applied. + true = Live =< Live0, %Assertion. + I = {set,Ds,Ss,{alloc,Live,AllocOp}}, + + %% Calculate liveness from the point of view of the preceding instruction. + %% The liveness is the union of live registers in the GC and the live + %% registers at the failure label. + Regs1 = live_call(Live), + Regs = live_join_alloc(AllocOp, D, Regs1), + live_opt_block(Is, Regs, D, [I|Acc]); +live_opt_block([{set,Ds,Ss,{bif,_,Fail}}=I|Is], Regs0, D, Acc) -> + Regs1 = x_dead(Ds, Regs0), + Regs2 = x_live(Ss, Regs1), + Regs = live_join_label(Fail, D, Regs2), + live_opt_block(Is, Regs, D, [I|Acc]); +live_opt_block([{set,Ds,Ss,_}=I|Is], Regs0, D, Acc) -> + Regs = x_live(Ss, x_dead(Ds, Regs0)), + live_opt_block(Is, Regs, D, [I|Acc]); +live_opt_block([{'%anno',_}|Is], Regs, D, Acc) -> + live_opt_block(Is, Regs, D, Acc); live_opt_block([], Regs, _, Acc) -> {Acc,Regs}. +live_join_alloc({Kind,_Name,Fail}, D, Regs) when Kind =:= gc_bif; Kind =:= put_map -> + live_join_label(Fail, D, Regs); +live_join_alloc(_, _, Regs) -> Regs. + live_join_labels([{f,L}|T], D, Regs0) when L =/= 0 -> Regs = gb_trees:get(L, D) bor Regs0, live_join_labels(T, D, Regs); @@ -848,3 +1092,224 @@ split_even([], Ss, Ds) -> {reverse(Ss),reverse(Ds)}; split_even([S,D|Rs], Ss, Ds) -> split_even(Rs, [S|Ss], [D|Ds]). + +%%% +%%% Add annotations for defined registers. +%%% +%%% This analysis is done by scanning the instructions in +%%% execution order. +%%% + +defs([{apply,_}=I|Is], _Regs, D) -> + [I|defs(Is, 1, D)]; +defs([{bif,_,{f,Fail},_Src,Dst}=I|Is], Regs0, D) -> + Regs = def_regs([Dst], Regs0), + [I|defs(Is, Regs, update_regs(Fail, Regs0, D))]; +defs([{block,Block0}|Is], Regs0, D0) -> + {Block,Regs,D} = defs_list(Block0, Regs0, D0), + [{block,[make_anno({def,Regs0})|Block]}|defs(Is, Regs, D)]; +defs([{bs_init,{f,L},_,Live,_,Dst}=I|Is], Regs0, D) -> + Regs1 = case Live of + none -> Regs0; + _ -> init_def_regs(Live) + end, + Regs = def_regs([Dst], Regs1), + [I|defs(Is, Regs, update_regs(L, Regs, D))]; +defs([{bs_put,{f,L},_,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, update_regs(L, Regs, D))]; +defs([build_stacktrace=I|Is], _Regs, D) -> + [I|defs(Is, 1, D)]; +defs([{call,_,_}=I|Is], _Regs, D) -> + [I|defs(Is, 1, D)]; +defs([{call_ext,_,{extfunc,M,F,A}}=I|Is], _Regs, D) -> + case erl_bifs:is_exit_bif(M, F, A) of + false -> + [I|defs(Is, 1, D)]; + true -> + [I|defs_unreachable(Is, D)] + end; +defs([{call_ext,_,_}=I|Is], _Regs, D) -> + [I|defs(Is, 1, D)]; +defs([{call_fun,_}=I|Is], _Regs, D) -> + [I|defs(Is, 1, D)]; +defs([{'catch',_,{f,L}}=I|Is], Regs, D) -> + RegsAtLabel = init_def_regs(1), + [I|defs(Is, Regs, update_regs(L, RegsAtLabel, D))]; +defs([{catch_end,_}=I|Is], _Regs, D) -> + Regs = init_def_regs(1), + [I|defs(Is, Regs, D)]; +defs([{gc_bif,_,{f,Fail},Live,_Src,Dst}=I|Is], Regs0, D) -> + true = all_defined(Live, Regs0), %Assertion. + Regs = def_regs([Dst], init_def_regs(Live)), + [I|defs(Is, Regs, update_regs(Fail, Regs0, D))]; +defs([{get_map_elements,{f,L},_Src,{list,DstList}}=I|Is], Regs0, D) -> + {_,Ds} = beam_utils:split_even(DstList), + Regs = def_regs(Ds, Regs0), + [I|defs(Is, Regs, update_regs(L, Regs0, D))]; +defs([{get_tuple_element,_,_,Dst}=I|Is], Regs0, D) -> + Regs = def_regs([Dst], Regs0), + [I|defs(Is, Regs, D)]; +defs([{jump,{f,L}}=I|Is], Regs, D) -> + [I|defs_unreachable(Is, update_regs(L, Regs, D))]; +defs([{label,L}=I|Is], Regs0, D) -> + case D of + #{L:=Regs1} -> + Regs = Regs0 band Regs1, + [I|defs(Is, Regs, D)]; + #{} -> + [I|defs(Is, Regs0, D)] + end; +defs([{loop_rec,{f,L},{x,0}}=I|Is], _Regs, D0) -> + RegsAtLabel = init_def_regs(0), + D = update_regs(L, RegsAtLabel, D0), + [I|defs(Is, init_def_regs(1), D)]; +defs([{loop_rec_end,_}=I|Is], _Regs, D) -> + [I|defs(Is, 0, D)]; +defs([{make_fun2,_,_,_,_}=I|Is], _Regs, D) -> + [I|defs(Is, 1, D)]; +defs([{move,_,Dst}=I|Is], Regs0, D) -> + Regs = def_regs([Dst], Regs0), + [I|defs(Is, Regs, D)]; +defs([{put_map,{f,Fail},_,_,Dst,_,_}=I|Is], Regs0, D) -> + Regs = def_regs([Dst], Regs0), + [I|defs(Is, Regs, update_regs(Fail, Regs0, D))]; +defs([raw_raise=I|Is], _Regs, D) -> + [I|defs(Is, 1, D)]; +defs([return=I|Is], _Regs, D) -> + [I|defs_unreachable(Is, D)]; +defs([{select,_,_Src,Fail,List}=I|Is], Regs, D0) -> + D = update_list([Fail|List], Regs, D0), + [I|defs_unreachable(Is, D)]; +defs([{test,_,{f,L},_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, update_regs(L, Regs, D))]; +defs([{test,_,{f,L},Live,_,Dst}=I|Is], Regs0, D) -> + true = all_defined(Live, Regs0), %Assertion. + Regs = def_regs([Dst], init_def_regs(Live)), + [I|defs(Is, Regs, update_regs(L, Regs0, D))]; +defs([{'try',_,{f,L}}=I|Is], Regs, D) -> + RegsAtLabel = init_def_regs(3), + [I|defs(Is, Regs, update_regs(L, RegsAtLabel, D))]; +defs([{try_case,_}=I|Is], _Regs, D) -> + [I|defs(Is, init_def_regs(3), D)]; +defs([{wait,_}=I|Is], _Regs, D) -> + [I|defs_unreachable(Is, D)]; +defs([{wait_timeout,_,_}=I|Is], _Regs, D) -> + [I|defs(Is, 0, D)]; + +%% Exceptions. +defs([{badmatch,_}=I|Is], _Regs, D) -> + [I|defs_unreachable(Is, D)]; +defs([{case_end,_}=I|Is], _Regs, D) -> + [I|defs_unreachable(Is, D)]; +defs([if_end=I|Is], _Regs, D) -> + [I|defs_unreachable(Is, D)]; +defs([{try_case_end,_}=I|Is], _Regs, D) -> + [I|defs_unreachable(Is, D)]; + +%% Neutral instructions +defs([{bs_context_to_binary,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{bs_restore2,_,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{bs_save2,_,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{deallocate,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{kill,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{line,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{recv_mark,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{recv_set,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([timeout=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{trim,_,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{try_end,_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([{'%',_}=I|Is], Regs, D) -> + [I|defs(Is, Regs, D)]; +defs([], _, _) -> []. + +defs_unreachable([{label,L}=I|Is], D) -> + case D of + #{L:=Regs} -> + [I|defs(Is, Regs, D)]; + #{} -> + defs_unreachable(Is, D) + end; +defs_unreachable([_|Is], D) -> + defs_unreachable(Is, D); +defs_unreachable([], _D) -> []. + +defs_list(Is, Regs, D) -> + defs_list(Is, Regs, D, []). + +defs_list([{set,Ds,_,{alloc,Live,Info}}=I|Is], Regs0, D0, Acc) -> + true = all_defined(Live, Regs0), %Assertion. + D = case Info of + {gc_bif,_,{f,Fail}} -> + update_regs(Fail, Regs0, D0); + {put_map,_,{f,Fail}} -> + update_regs(Fail, Regs0, D0); + _ -> + D0 + end, + Regs = def_regs(Ds, init_def_regs(Live)), + defs_list(Is, Regs, D, [I|Acc]); +defs_list([{set,Ds,_,Info}=I|Is], Regs0, D0, Acc) -> + D = case Info of + {bif,_,{f,Fail}} -> + update_regs(Fail, Regs0, D0); + {try_catch,'catch',{f,Fail}} -> + update_regs(Fail, init_def_regs(1), D0); + {try_catch,'try',{f,Fail}} -> + update_regs(Fail, init_def_regs(3), D0); + _ -> + D0 + end, + Regs = def_regs(Ds, Regs0), + defs_list(Is, Regs, D, [I|Acc]); +defs_list([], Regs, D, Acc) -> + {reverse(Acc),Regs,D}. + +init_def_regs(Arity) -> + (1 bsl Arity) - 1. + +def_regs([{x,X}|T], Regs) -> + def_regs(T, Regs bor (1 bsl X)); +def_regs([_|T], Regs) -> + def_regs(T, Regs); +def_regs([], Regs) -> Regs. + +update_list([{f,L}|T], Regs, D0) -> + D = update_regs(L, Regs, D0), + update_list(T, Regs, D); +update_list([_|T], Regs, D) -> + update_list(T, Regs, D); +update_list([], _Regs, D) -> D. + +update_regs(L, Regs0, D) -> + case D of + #{L:=Regs1} -> + Regs = Regs0 band Regs1, + D#{L:=Regs}; + #{} -> + D#{L=>Regs0} + end. + +all_defined(Live, Regs) -> + All = (1 bsl Live) - 1, + Regs band All =:= All. + +%%% +%%% Utilities. +%%% + +%% make_anno(Anno) -> WrappedAnno. +%% Wrap an annotation term. + +make_anno(Anno) -> + {'%anno',Anno}. |