%% -*- erlang-indent-level: 2 -*-
%%
%% 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.
-module(hipe_x86_cfg).
-export([init/1,
labels/1, start_label/1,
succ/2, pred/2,
bb/2, bb_add/3, map_bbs/2, fold_bbs/3]).
-export([postorder/1, reverse_postorder/1]).
-export([linearise/1, params/1, arity/1, redirect_jmp/3, branch_preds/1]).
%%% these tell cfg.inc what to define (ugly as hell)
-define(PRED_NEEDED,true).
-define(BREADTH_ORDER,true).
-define(PARAMS_NEEDED,true).
-define(START_LABEL_UPDATE_NEEDED,true).
-define(MAP_FOLD_NEEDED,true).
-include("hipe_x86.hrl").
-include("../flow/cfg.hrl").
-include("../flow/cfg.inc").
init(Defun) ->
%% XXX: this assumes that the code starts with a label insn.
%% Is that guaranteed?
Code = hipe_x86:defun_code(Defun),
StartLab = hipe_x86:label_label(hd(Code)),
Data = hipe_x86:defun_data(Defun),
IsClosure = hipe_x86:defun_is_closure(Defun),
MFA = hipe_x86:defun_mfa(Defun),
IsLeaf = hipe_x86:defun_is_leaf(Defun),
Formals = hipe_x86:defun_formals(Defun),
CFG0 = mk_empty_cfg(MFA, StartLab, Data, IsClosure, IsLeaf, Formals),
take_bbs(Code, CFG0).
is_branch(I) ->
case I of
#jmp_fun{} -> true;
#jmp_label{} -> true;
#jmp_switch{} -> true;
#pseudo_call{} -> true;
#pseudo_jcc{} -> true;
#pseudo_tailcall{} -> true;
#ret{} -> true;
_ -> false
end.
branch_successors(Branch) ->
case Branch of
#jmp_fun{} -> [];
#jmp_label{label=Label} -> [Label];
#jmp_switch{labels=Labels} -> Labels;
#pseudo_call{contlab=ContLab, sdesc=#x86_sdesc{exnlab=ExnLab}} ->
case ExnLab of
[] -> [ContLab];
_ -> [ContLab,ExnLab]
end;
#pseudo_jcc{true_label=TrueLab,false_label=FalseLab} -> [FalseLab,TrueLab];
#pseudo_tailcall{} -> [];
#ret{} -> []
end.
branch_preds(Branch) ->
case Branch of
#jmp_switch{labels=Labels} ->
Prob = 1.0/length(Labels),
[{L, Prob} || L <- Labels];
#pseudo_call{contlab=ContLab, sdesc=#x86_sdesc{exnlab=[]}} ->
%% A function can still cause an exception, even if we won't catch it
[{ContLab, 1.0-hipe_bb_weights:call_exn_pred()}];
#pseudo_call{contlab=ContLab, sdesc=#x86_sdesc{exnlab=ExnLab}} ->
CallExnPred = hipe_bb_weights:call_exn_pred(),
[{ContLab, 1.0-CallExnPred}, {ExnLab, CallExnPred}];
#pseudo_jcc{true_label=TrueLab,false_label=FalseLab,pred=Pred} ->
[{FalseLab, 1.0-Pred}, {TrueLab, Pred}];
_ ->
case branch_successors(Branch) of
[] -> [];
[Single] -> [{Single, 1.0}]
end
end.
-ifdef(REMOVE_TRIVIAL_BBS_NEEDED).
fails_to(_Instr) -> [].
-endif.
redirect_jmp(I, Old, New) ->
case I of
#jmp_label{label=Label} ->
if Old =:= Label -> I#jmp_label{label=New};
true -> I
end;
#pseudo_jcc{true_label=TrueLab, false_label=FalseLab} ->
J0 = if Old =:= TrueLab -> I#pseudo_jcc{true_label=New};
true -> I
end,
if Old =:= FalseLab -> J0#pseudo_jcc{false_label=New};
true -> J0
end;
%% handle pseudo_call too?
_ -> I
end.
%%% XXX: fix if labels can occur in operands
%% redirect_ops(_Labels, CFG, _Map) ->
%% CFG.
mk_goto(Label) ->
hipe_x86:mk_jmp_label(Label).
is_label(I) ->
case I of #label{} -> true; _ -> false end.
label_name(Label) ->
hipe_x86:label_label(Label).
mk_label(Name) ->
hipe_x86:mk_label(Name).
%% is_comment(I) ->
%% hipe_x86:is_comment(I).
%%
%% is_goto(I) ->
%% hipe_x86:is_jmp_label(I).
linearise(CFG) -> % -> defun, not insn list
MFA = function(CFG),
Formals = params(CFG),
Code = linearize_cfg(CFG),
Data = data(CFG),
VarRange = hipe_gensym:var_range(x86),
LabelRange = hipe_gensym:label_range(x86),
IsClosure = is_closure(CFG),
IsLeaf = is_leaf(CFG),
hipe_x86:mk_defun(MFA, Formals, IsClosure, IsLeaf,
Code, Data, VarRange, LabelRange).
arity(CFG) ->
{_M,_F,A} = function(CFG),
A.
%% init_gensym(CFG) ->
%% HighestVar = find_highest_var(CFG),
%% HighestLabel = find_highest_label(CFG),
%% hipe_gensym:init(),
%% hipe_gensym:set_var(x86, HighestVar),
%% hipe_gensym:set_label(x86, HighestLabel).
%%
%% highest_var(Code) ->
%% hipe_x86:highest_temp(Code).
