aboutsummaryrefslogtreecommitdiffstats
path: root/lib/compiler/src/beam_a.erl
blob: 0bccad1ecd1312d129dce39e18f67a0c7a47ce54 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2012-2018. 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.
%% You may obtain a copy of the License at
%%
%%     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%
%%
%% Purpose: Run directly after code generation to do any normalization
%%          or preparation to simplify the optimization passes.
%%          (Mandatory.)

-module(beam_a).

-export([module/2]).

-spec module(beam_asm:module_code(), [compile:option()]) ->
                    {'ok',beam_utils:module_code()}.

module({Mod,Exp,Attr,Fs0,Lc}, _Opt) ->
    Fs = [function(F) || F <- Fs0],
    {ok,{Mod,Exp,Attr,Fs,Lc}}.

function({function,Name,Arity,CLabel,Is0}) ->
    try
	%% Rename certain operations to simplify the optimization passes.
	Is1 = rename_instrs(Is0),

	%% Remove unusued labels for cleanliness and to help
	%% optimization passes and HiPE.
	Is2 = beam_jump:remove_unused_labels(Is1),

        %% Some optimization passes can't handle consecutive labels.
        %% Coalesce multiple consecutive labels.
        Is = coalesce_consecutive_labels(Is2, [], []),

        {function,Name,Arity,CLabel,Is}
    catch
        Class:Error:Stack ->
	    io:fwrite("Function: ~w/~w\n", [Name,Arity]),
	    erlang:raise(Class, Error, Stack)
    end.

rename_instrs([{test,is_eq_exact,_,[Dst,Src]}=Test,
               {move,Src,Dst}|Is]) ->
    %% The move instruction is not needed.
    rename_instrs([Test|Is]);
rename_instrs([{test,is_eq_exact,_,[Same,Same]}|Is]) ->
    %% Same literal or same register. Will always succeed.
    rename_instrs(Is);
rename_instrs([{loop_rec,{f,Fail},{x,0}},{loop_rec_end,_},{label,Fail}|Is]) ->
    %% This instruction sequence does nothing.
    rename_instrs(Is);
rename_instrs([{apply_last,A,N}|Is]) ->
    [{apply,A},{deallocate,N},return|rename_instrs(Is)];
rename_instrs([{call_last,A,F,N}|Is]) ->
    [{call,A,F},{deallocate,N},return|rename_instrs(Is)];
rename_instrs([{call_ext_last,A,F,N}|Is]) ->
    [{call_ext,A,F},{deallocate,N},return|rename_instrs(Is)];
rename_instrs([{call_only,A,F}|Is]) ->
    [{call,A,F},return|rename_instrs(Is)];
rename_instrs([{call_ext_only,A,F}|Is]) ->
    [{call_ext,A,F},return|rename_instrs(Is)];
rename_instrs([{'%live',_}|Is]) ->
    %% Ignore old type of live annotation. Only happens when compiling
    %% from very old .S files.
    rename_instrs(Is);
rename_instrs([{get_list,S,D1,D2}|Is]) ->
    %% Only happens when compiling from old .S files.
    if
        D1 =:= S ->
            [{get_tl,S,D2},{get_hd,S,D1}|rename_instrs(Is)];
        true ->
            [{get_hd,S,D1},{get_tl,S,D2}|rename_instrs(Is)]
    end;
rename_instrs([I|Is]) ->
    [rename_instr(I)|rename_instrs(Is)];
rename_instrs([]) -> [].

rename_instr({bs_put_binary=I,F,Sz,U,Fl,Src}) ->
    {bs_put,F,{I,U,Fl},[Sz,Src]};
rename_instr({bs_put_float=I,F,Sz,U,Fl,Src}) ->
    {bs_put,F,{I,U,Fl},[Sz,Src]};
rename_instr({bs_put_integer=I,F,Sz,U,Fl,Src}) ->
    {bs_put,F,{I,U,Fl},[Sz,Src]};
rename_instr({bs_put_utf8=I,F,Fl,Src}) ->
    {bs_put,F,{I,Fl},[Src]};
rename_instr({bs_put_utf16=I,F,Fl,Src}) ->
    {bs_put,F,{I,Fl},[Src]};
rename_instr({bs_put_utf32=I,F,Fl,Src}) ->
    {bs_put,F,{I,Fl},[Src]};
rename_instr({bs_put_string,_,{string,String}}) ->
    %% Only happens when compiling from .S files. In old
    %% .S files, String is a list. In .S in OTP 22 and later,
    %% String is a binary.
    {bs_put,{f,0},{bs_put_binary,8,{field_flags,[unsigned,big]}},
     [{atom,all},{literal,iolist_to_binary([String])}]};
rename_instr({bs_add=I,F,[Src1,Src2,U],Dst}) when is_integer(U) ->
    {bif,I,F,[Src1,Src2,{integer,U}],Dst};
rename_instr({bs_utf8_size=I,F,Src,Dst}) ->
    {bif,I,F,[Src],Dst};
rename_instr({bs_utf16_size=I,F,Src,Dst}) ->
    {bif,I,F,[Src],Dst};
rename_instr({bs_init2=I,F,Sz,Extra,Live,Flags,Dst}) ->
    {bs_init,F,{I,Extra,Flags},Live,[Sz],Dst};
rename_instr({bs_init_bits=I,F,Sz,Extra,Live,Flags,Dst}) ->
    {bs_init,F,{I,Extra,Flags},Live,[Sz],Dst};
rename_instr({bs_append=I,F,Sz,Extra,Live,U,Src,Flags,Dst}) ->
    {bs_init,F,{I,Extra,U,Flags},Live,[Sz,Src],Dst};
rename_instr({bs_private_append=I,F,Sz,U,Src,Flags,Dst}) ->
    {bs_init,F,{I,U,Flags},none,[Sz,Src],Dst};
rename_instr(bs_init_writable=I) ->
    {bs_init,{f,0},I,1,[{x,0}],{x,0}};
rename_instr({put_map_assoc,Fail,S,D,R,L}) ->
    {put_map,Fail,assoc,S,D,R,L};
rename_instr({put_map_exact,Fail,S,D,R,L}) ->
    {put_map,Fail,exact,S,D,R,L};
rename_instr({test,has_map_fields,Fail,Src,{list,List}}) ->
    {test,has_map_fields,Fail,[Src|List]};
rename_instr({test,is_nil,Fail,[Src]}) ->
    {test,is_eq_exact,Fail,[Src,nil]};
rename_instr({select_val=I,Reg,Fail,{list,List}}) ->
    {select,I,Reg,Fail,List};
rename_instr({select_tuple_arity=I,Reg,Fail,{list,List}}) ->
    {select,I,Reg,Fail,List};
rename_instr(send) ->
    {call_ext,2,send};
rename_instr(I) -> I.

coalesce_consecutive_labels([{label,L}=Lbl,{label,Alias}|Is], Replace, Acc) ->
    coalesce_consecutive_labels([Lbl|Is], [{Alias,L}|Replace], Acc);
coalesce_consecutive_labels([I|Is], Replace, Acc) ->
    coalesce_consecutive_labels(Is, Replace, [I|Acc]);
coalesce_consecutive_labels([], Replace, Acc) ->
    D = maps:from_list(Replace),
    beam_utils:replace_labels(Acc, [], D, fun(L) -> L end).