hipe_arm_assemble.erl

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  NewS = do_s(false),
  NewDstLo = do_reg(DstLo),
  NewDstHi = do_reg(DstHi),
  NewSrc1 = do_reg(Src1),
  NewSrc2 = do_reg(Src2),
  [{'smull', {NewCond,NewS,NewDstLo,NewDstHi,NewSrc1,NewSrc2}, I}].

do_store(I) ->
  #store{stop=StOp,src=Src,am2=Am2} = I,
  NewCond = do_cond('al'),
  NewSrc = do_reg(Src),
  NewAm2 = do_am2(Am2),
  [{StOp, {NewCond,NewSrc,NewAm2}, I}].

do_reg(#arm_temp{reg=Reg,type=Type})
  when is_integer(Reg), 0 =< Reg, Reg < 16, Type =/= 'double' ->
  {r,Reg}.
  
do_cond(Cond) -> {'cond',Cond}.

do_s(S) -> {'s', case S of false -> 0; true -> 1 end}.

do_label_ref(Label) when is_integer(Label) ->
  {label,Label}.	% symbolic, since offset is not yet computable

do_am1(Am1) ->
  case Am1 of
    #arm_temp{} -> do_reg(Am1);
    {Src1,'rrx'} -> {do_reg(Src1),'rrx'};
    {Src1,ShiftOp,Src2=#arm_temp{}} -> {do_reg(Src1),{ShiftOp,do_reg(Src2)}};
    {Src1,ShiftOp,Imm5} -> {do_reg(Src1),{ShiftOp,{imm5,Imm5}}};
    {Imm8,Imm4} -> {{imm8,Imm8},{imm4,Imm4}}
  end.

do_am2(#am2{src=Src,sign=Sign,offset=Offset}) ->
  NewSrc = do_reg(Src),
  case Offset of
    #arm_temp{} -> {'register_offset',NewSrc,Sign,do_reg(Offset)};
    {Src3,'rrx'} -> {'scaled_register_offset',NewSrc,Sign,do_reg(Src3),'rrx'};
    {Src3,ShiftOp,Imm5} -> {'scaled_register_offset',NewSrc,Sign,do_reg(Src3),{ShiftOp,{imm5,Imm5}}};
    Imm12 -> {'immediate_offset',NewSrc,Sign,{imm12,Imm12}}
  end.

do_am3(#am3{src=Src,sign=Sign,offset=Offset}) ->
  NewSrc = do_reg(Src),
  case Offset of
    #arm_temp{} -> {'register_offset',NewSrc,Sign,do_reg(Offset)};
    _ -> {'immediate_offset',NewSrc,Sign,{'imm8',Offset}}
  end.

%%%
%%% Assembly Pass 3.
%%% Process final {MFA,Code,CodeSize,LabelMap} list from pass 2.
%%% Translate to a single binary code segment.
%%% Collect relocation patches.
%%% Build ExportMap (MFA-to-address mapping).
%%% Combine LabelMaps to a single one (for mk_data_relocs/2 compatibility).
%%% Return {CombinedCodeSize,BinaryCode,Relocs,CombinedLabelMap,ExportMap}.
%%%

encode(Code, Options) ->
  CodeSize = compute_code_size(Code, 0),
  ExportMap = build_export_map(Code, 0, []),
  {AccCode,Relocs} = encode_mfas(Code, 0, [], [], Options),
  CodeBinary = list_to_binary(lists:reverse(AccCode)),
  ?ASSERT(CodeSize =:= size(CodeBinary)),
  CombinedLabelMap = combine_label_maps(Code, 0, gb_trees:empty()),
  {CodeSize,CodeBinary,Relocs,CombinedLabelMap,ExportMap}.

compute_code_size([{_MFA,_Insns,CodeSize,_LabelMap}|Code], Size) ->
  compute_code_size(Code, Size+CodeSize);
compute_code_size([], Size) -> Size.

build_export_map([{{M,F,A},_Insns,CodeSize,_LabelMap}|Code], Address, ExportMap) ->
  build_export_map(Code, Address+CodeSize, [{Address,M,F,A}|ExportMap]);
build_export_map([], _Address, ExportMap) -> ExportMap.

combine_label_maps([{MFA,_Insns,CodeSize,LabelMap}|Code], Address, CLM) ->
  NewCLM = merge_label_map(gb_trees:to_list(LabelMap), MFA, Address, CLM),
  combine_label_maps(Code, Address+CodeSize, NewCLM);
combine_label_maps([], _Address, CLM) -> CLM.

merge_label_map([{Label,Offset}|Rest], MFA, Address, CLM) ->
  NewCLM = gb_trees:insert({MFA,Label}, Address+Offset, CLM),
  merge_label_map(Rest, MFA, Address, NewCLM);
merge_label_map([], _MFA, _Address, CLM) -> CLM.

encode_mfas([{MFA,Insns,CodeSize,LabelMap}|Code], Address, AccCode, Relocs, Options) ->
  print("Generating code for: ~w\n", [MFA], Options),
  print("Offset   | Opcode   | Instruction\n", [], Options),
  {Address1,Relocs1,AccCode1} =
    encode_insns(Insns, Address, Address, LabelMap, Relocs, AccCode, Options),
  ExpectedAddress = Address + CodeSize,
  ?ASSERT(Address1 =:= ExpectedAddress),
  print("Finished.\n", [], Options),
  encode_mfas(Code, Address1, AccCode1, Relocs1, Options);
encode_mfas([], _Address, AccCode, Relocs, _Options) ->
  {AccCode,Relocs}.

encode_insns([I|Insns], Address, FunAddress, LabelMap, Relocs, AccCode, Options) ->
  case I of
    {'.label',L,_} ->
      LabelAddress = gb_trees:get(L, LabelMap) + FunAddress,
      ?ASSERT(Address =:= LabelAddress),	% sanity check
      print_insn(Address, [], I, Options),
      encode_insns(Insns, Address, FunAddress, LabelMap, Relocs, AccCode, Options);
    {'.reloc',Data,_} ->
      print_insn(Address, [], I, Options),
      Reloc = encode_reloc(Data, Address, FunAddress, LabelMap),
      encode_insns(Insns, Address, FunAddress, LabelMap, [Reloc|Relocs], AccCode, Options);
    {'.long',Value,_} ->
      print_insn(Address, Value, I, Options),
      Segment = <<Value:32/integer-big>>,
      NewAccCode = [Segment|AccCode],
      encode_insns(Insns, Address+4, FunAddress, LabelMap, Relocs, NewAccCode, Options);
    _ ->
      {Op,Arg,_} = fix_pc_refs(I, Address, FunAddress, LabelMap),
      Word = hipe_arm_encode:insn_encode(Op, Arg),
      print_insn(Address, Word, I, Options),
      Segment = <<Word:32/integer-big>>,
      NewAccCode = [Segment|AccCode],
      encode_insns(Insns, Address+4, FunAddress, LabelMap, Relocs, NewAccCode, Options)
  end;
encode_insns([], Address, _FunAddress, _LabelMap, Relocs, AccCode, _Options) ->
  {Address,Relocs,AccCode}.

encode_reloc(Data, Address, FunAddress, LabelMap) ->
  case Data of
    {b_fun,MFAorPrim,Linkage} ->
      %% b and bl are patched the same, so no need to distinguish
      %% call from tailcall
      PatchTypeExt =
	case Linkage of
	  remote -> ?CALL_REMOTE;
	  not_remote -> ?CALL_LOCAL
	end,
      {PatchTypeExt, Address, untag_mfa_or_prim(MFAorPrim)};
    {load_atom,Atom} ->
      {?LOAD_ATOM, Address, Atom};
    {load_address,X} ->
      {?LOAD_ADDRESS, Address, X};
    {sdesc,SDesc} ->
      #arm_sdesc{exnlab=ExnLab,fsize=FSize,arity=Arity,live=Live} = SDesc,
      ExnRA =
	case ExnLab of
	  [] -> [];	% don't cons up a new one
	  ExnLab -> gb_trees:get(ExnLab, LabelMap) + FunAddress
	end,
      {?SDESC, Address,
       ?STACK_DESC(ExnRA, FSize, Arity, Live)}
  end.

untag_mfa_or_prim(#arm_mfa{m=M,f=F,a=A}) -> {M,F,A};
untag_mfa_or_prim(#arm_prim{prim=Prim}) -> Prim.

fix_pc_refs(I, InsnAddress, FunAddress, LabelMap) ->
  case I of
    {b, {Cond,{label,L}}, OrigI} ->
      LabelAddress = gb_trees:get(L, LabelMap) + FunAddress,
      Imm24 = (LabelAddress - (InsnAddress+8)) div 4,
      %% ensure Imm24 fits in a 24 bit sign-extended field
      ?ASSERT(Imm24 =<   16#7FFFFF),
      ?ASSERT(Imm24 >= -(16#800000)),
      {b, {Cond,{imm24,Imm24 band 16#FFFFFF}}, OrigI};
    {'.pseudo_li', {Dst,{label,L}}, OrigI} ->
      LabelAddress = gb_trees:get(L, LabelMap) + FunAddress,
      Offset = LabelAddress - (InsnAddress+8),
      {Sign,Imm12} =
	if Offset < 0 -> {'-', -Offset};
	   true -> {'+', Offset}
	end,
      ?ASSERT(Imm12 =< 16#FFF),
      Am2 = {'immediate_offset',{r,15},Sign,{imm12,Imm12}},
      {ldr, {do_cond('al'),Dst,Am2}, OrigI};
    _ -> I
  end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

mk_data_relocs(RefsFromConsts, LabelMap) ->
  lists:flatten(mk_data_relocs(RefsFromConsts, LabelMap, [])).

mk_data_relocs([{MFA,Labels} | Rest], LabelMap, Acc) ->
  Map = [case Label of
	   {L,Pos} ->
	     Offset = find({MFA,L}, LabelMap),
	     {Pos,Offset};
	   {sorted,Base,OrderedLabels} ->
	     {sorted, Base, [begin
			       Offset = find({MFA,L}, LabelMap),
			       {Order, Offset}
			     end
			     || {L,Order} <- OrderedLabels]}
	 end
	 || Label <- Labels],
  %% msg("Map: ~w Map\n",[Map]),
  mk_data_relocs(Rest, LabelMap, [Map,Acc]);
mk_data_relocs([],_,Acc) -> Acc.

find({MFA,L},LabelMap) ->
  gb_trees:get({MFA,L}, LabelMap).

slim_sorted_exportmap([{Addr,M,F,A}|Rest], Closures, Exports) ->
  IsClosure = lists:member({M,F,A}, Closures),
  IsExported = is_exported(F, A, Exports),
  [Addr,M,F,A,IsClosure,IsExported | slim_sorted_exportmap(Rest, Closures, Exports)];
slim_sorted_exportmap([],_,_) -> [].

is_exported(F, A, Exports) -> lists:member({F,A}, Exports).

%%%
%%% Assembly listing support (pp_asm option).
%%%

print(String, Arglist, Options) ->
  ?when_option(pp_asm, Options, io:format(String, Arglist)).

print_insn(Address, Word, I, Options) ->
  ?when_option(pp_asm, Options, print_insn_2(Address, Word, I)).

print_insn_2(Address, Word, {NewI,NewArgs,OrigI}) ->
  io:format("~8.16.0b | ", [Address]),
  print_code_list(word_to_bytes(Word), 0),
  case NewI of
    '.long' ->
      io:format("\t.long ~.16x\n", [Word, "0x"]);
    '.reloc' ->
      io:format("\t.reloc ~w\n", [NewArgs]);
    _ ->
      hipe_arm_pp:pp_insn(OrigI)
  end.

word_to_bytes(W) ->
  case W of
    [] -> [];	% label or other pseudo instruction
    _ -> [(W bsr 24) band 16#FF, (W bsr 16) band 16#FF,
	  (W bsr 8) band 16#FF, W band 16#FF]
  end.

print_code_list([Byte|Rest], Len) ->
  print_byte(Byte),
  print_code_list(Rest, Len+1);
print_code_list([], Len) ->
  fill_spaces(8-(Len*2)),
  io:format(" | ").

print_byte(Byte) ->
  io:format("~2.16.0b", [Byte band 16#FF]).

fill_spaces(N) when N > 0 ->
  io:format(" "),
  fill_spaces(N-1);
fill_spaces(0) ->
  [].

%%%
%%% Lookup a constant in a ConstMap.
%%%

find_const({MFA,Label},[{pcm_entry,MFA,Label,ConstNo,_,_,_}|_]) ->
  ConstNo;
find_const(N,[_|R]) ->
  find_const(N,R);
find_const(C,[]) ->
  ?EXIT({constant_not_found,C}).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%
%%% ADT for previous immediates.
%%% This is a queue (fifo) of the previously defined immediates,
%%% plus a mapping from these immediates to their labels.
%%%
-record(previous, {set, head, tail}). % INV: tail=[] if head=[]

previous_empty() -> #previous{set=gb_trees:empty(), head=[], tail=[]}.

previous_lookup(#previous{set=S}, Imm) -> gb_trees:lookup(Imm, S).

previous_findmin(#previous{head=H}) ->
  case H of
    [X|_] -> X;
    _ -> []
  end.

previous_delmin(#previous{set=S, head=[{_Address,Imm}|H], tail=T}) ->
  {NewH,NewT} =
    case H of
      [] -> {lists:reverse(T), []};
      _ -> {H, T}
    end,
  #previous{set=gb_trees:delete(Imm, S), head=NewH, tail=NewT}.

previous_append(#previous{set=S, head=H, tail=T}, Address, Lab, Imm) ->
  {NewH,NewT} =
    case H of
      [] -> {[{Address,Imm}], []};
      _  -> {H, [{Address,Imm}|T]}
    end,
  #previous{set=gb_trees:insert(Imm, Lab, S), head=NewH, tail=NewT}.

%%%
%%% ADT for pending immediates.
%%% This is a queue (fifo) of immediates pending definition,
%%% plus a mapping from these immediates to their labels,
%%% and a recording of the first (lowest) code address referring
%%% to a pending immediate.
%%%
-record(pending, {set, list, firstref}).

pending_empty() -> #pending{set=gb_trees:empty(), list=[], firstref=[]}.

pending_to_list(#pending{list=L}) -> lists:reverse(L).

pending_lookup(#pending{set=S}, Imm) -> gb_trees:lookup(Imm, S).

pending_firstref(#pending{firstref=F}) -> F.

pending_append(#pending{set=S, list=L, firstref=F}, Address, Lab, RelocOrInt, Imm) ->
  #pending{set=gb_trees:insert(Imm, Lab, S),
	   list=[{Lab,RelocOrInt,Imm}|L],
	   firstref=case F of [] -> Address; _ -> F end}.

pending_size(#pending{list=L}) -> length(L).