Files
mercury/compiler/follow_code.m
Zoltan Somogyi 89644bebb2 Fixed a bug that caused restores of succip to be put in the wrong
Estimated hours taken: 5

peephole:
	Fixed a bug that caused restores of succip to be put in the wrong
	place, but only after predicate-wide value numbering.

opt_debug:
	Added a couple of debugging predicates used in tracking down this bug.

value_number:
	Fix a bug that left a livevals pseudo-op in the wrong place if a
	single instruction sequence contained more than one such pseudo-op.

options:
	Add --debug-opt. Rename --vndebug to --debug-vn.
	Add --generate-bytecode.

optimize, vn_debug:
	Use the new routines in opt_debug, and use the new/renamed options.

store_alloc:
	Don't thread follow_vars through the module, since the follow_vars
	information is not attached directly to branched structures. We
	now also use the same slot to hold the store map computed by this
	pass; this should allow the later deletion of the store map slot
	from goal_infos.

follow_code:
	Removed dead predicate.

livemap:
	Added a comment.
1996-05-12 04:51:14 +00:00

418 lines
15 KiB
Mathematica

%-----------------------------------------------------------------------------%
% Copyright (C) 1995 University of Melbourne.
% This file may only be copied under the terms of the GNU General
% Public License - see the file COPYING in the Mercury distribution.
%-----------------------------------------------------------------------------%
% Main author: conway.
% Extensive modifications by zs.
%-----------------------------------------------------------------------------%
:- module follow_code.
:- interface.
:- import_module hlds_module, hlds_pred, llds.
:- import_module bool, std_util.
:- pred move_follow_code(module_info, pair(bool), module_info).
:- mode move_follow_code(in, in, out) is det.
:- pred move_follow_code_in_proc(proc_info, proc_info,
pair(bool), module_info, module_info).
% :- mode move_follow_code_in_proc(di, uo, in, di, uo) is det.
:- mode move_follow_code_in_proc(in, out, in, in, out) is det.
%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%
:- implementation.
:- import_module hlds_goal, hlds_data, goal_util, mode_util.
:- import_module det_analysis, quantification.
:- import_module list, map, set.
:- import_module term, require.
%-----------------------------------------------------------------------------%
move_follow_code(ModuleInfo0, Flags, ModuleInfo1) :-
module_info_predids(ModuleInfo0, PredIds),
move_follow_code_in_preds(PredIds, Flags, ModuleInfo0, ModuleInfo1).
:- pred move_follow_code_in_preds(list(pred_id), pair(bool),
module_info, module_info).
:- mode move_follow_code_in_preds(in, in, in, out) is det.
move_follow_code_in_preds([], _Flags, ModuleInfo, ModuleInfo).
move_follow_code_in_preds([PredId | PredIds], Flags,
ModuleInfo0, ModuleInfo) :-
module_info_preds(ModuleInfo0, PredTable),
map__lookup(PredTable, PredId, PredInfo),
pred_info_non_imported_procids(PredInfo, ProcIds),
move_follow_code_in_procs(ProcIds, PredId, Flags,
ModuleInfo0, ModuleInfo1),
move_follow_code_in_preds(PredIds, Flags, ModuleInfo1, ModuleInfo).
:- pred move_follow_code_in_procs(list(proc_id), pred_id, pair(bool),
module_info, module_info).
:- mode move_follow_code_in_procs(in, in, in, in, out) is det.
move_follow_code_in_procs([], _PredId, _Flags, ModuleInfo, ModuleInfo).
move_follow_code_in_procs([ProcId | ProcIds], PredId,
Flags, ModuleInfo0, ModuleInfo) :-
module_info_preds(ModuleInfo0, PredTable0),
map__lookup(PredTable0, PredId, PredInfo0),
pred_info_procedures(PredInfo0, ProcTable0),
map__lookup(ProcTable0, ProcId, ProcInfo0),
move_follow_code_in_proc(ProcInfo0, ProcInfo, Flags,
ModuleInfo0, ModuleInfo1),
map__set(ProcTable0, ProcId, ProcInfo, ProcTable),
pred_info_set_procedures(PredInfo0, ProcTable, PredInfo),
map__set(PredTable0, PredId, PredInfo, PredTable),
module_info_set_preds(ModuleInfo1, PredTable, ModuleInfo2),
move_follow_code_in_procs(ProcIds, PredId, Flags,
ModuleInfo2, ModuleInfo).
move_follow_code_in_proc(ProcInfo0, ProcInfo, Flags,
ModuleInfo0, ModuleInfo) :-
proc_info_goal(ProcInfo0, Goal0),
proc_info_variables(ProcInfo0, Varset0),
proc_info_vartypes(ProcInfo0, VarTypes0),
(
move_follow_code_in_goal(Goal0, Goal1, Flags, no, Res),
% did the goal change?
Res = yes
->
% we need to fix up the goal_info by recalculating
% the nonlocal vars and the non-atomic instmap deltas.
proc_info_headvars(ProcInfo0, HeadVars),
implicitly_quantify_clause_body(HeadVars, Goal1,
Varset0, VarTypes0, Goal2, Varset, VarTypes, _Warnings),
recompute_instmap_delta(Goal2, Goal, ModuleInfo0, ModuleInfo)
;
Goal = Goal0,
Varset = Varset0,
VarTypes = VarTypes0,
ModuleInfo = ModuleInfo0
),
proc_info_set_goal(ProcInfo0, Goal, ProcInfo1),
proc_info_set_varset(ProcInfo1, Varset, ProcInfo2),
proc_info_set_vartypes(ProcInfo2, VarTypes, ProcInfo).
%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%
:- pred move_follow_code_in_goal(hlds__goal, hlds__goal, pair(bool),
bool, bool).
:- mode move_follow_code_in_goal(in, out, in, in, out) is det.
move_follow_code_in_goal(Goal0 - GoalInfo, Goal - GoalInfo, Flags, R0, R) :-
move_follow_code_in_goal_2(Goal0, Goal, Flags, R0, R).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_in_goal_2(hlds__goal_expr, hlds__goal_expr,
pair(bool), bool, bool).
:- mode move_follow_code_in_goal_2(in, out, in, in, out) is det.
move_follow_code_in_goal_2(conj(Goals0), conj(Goals), Flags, R0, R) :-
move_follow_code_in_conj(Goals0, Goals, Flags, R0, R).
move_follow_code_in_goal_2(disj(Goals0, FV), disj(Goals, FV), Flags, R0, R) :-
move_follow_code_in_disj(Goals0, Goals, Flags, R0, R).
move_follow_code_in_goal_2(not(Goal0), not(Goal), Flags, R0, R) :-
move_follow_code_in_goal(Goal0, Goal, Flags, R0, R).
move_follow_code_in_goal_2(switch(Var, Det, Cases0, FV),
switch(Var, Det, Cases, FV), Flags, R0, R) :-
move_follow_code_in_cases(Cases0, Cases, Flags, R0, R).
move_follow_code_in_goal_2(if_then_else(Vars, Cond0, Then0, Else0, FV),
if_then_else(Vars, Cond, Then, Else, FV), Flags, R0, R) :-
move_follow_code_in_goal(Cond0, Cond, Flags, R0, R1),
move_follow_code_in_goal(Then0, Then, Flags, R1, R2),
move_follow_code_in_goal(Else0, Else, Flags, R2, R).
move_follow_code_in_goal_2(some(Vars, Goal0), some(Vars, Goal), Flags, R0, R) :-
move_follow_code_in_goal(Goal0, Goal, Flags, R0, R).
move_follow_code_in_goal_2(higher_order_call(A,B,C,D,E,F),
higher_order_call(A,B,C,D,E,F), _, R, R).
move_follow_code_in_goal_2(call(A,B,C,D,E,F,G), call(A,B,C,D,E,F,G), _, R, R).
move_follow_code_in_goal_2(unify(A,B,C,D,E), unify(A,B,C,D,E), _, R, R).
move_follow_code_in_goal_2(
pragma_c_code(C_Code, PredId, ProcId, Args, ArgNameMap),
pragma_c_code(C_Code, PredId, ProcId, Args, ArgNameMap),
_, R, R).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_in_disj(list(hlds__goal), list(hlds__goal),
pair(bool), bool, bool).
:- mode move_follow_code_in_disj(in, out, in, in, out) is det.
move_follow_code_in_disj([], [], _, R, R).
move_follow_code_in_disj([Goal0|Goals0], [Goal|Goals], Flags, R0, R) :-
move_follow_code_in_goal(Goal0, Goal, Flags, R0, R1),
move_follow_code_in_disj(Goals0, Goals, Flags, R1, R).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_in_cases(list(case), list(case), pair(bool),
bool, bool).
:- mode move_follow_code_in_cases(in, out, in, in, out) is det.
move_follow_code_in_cases([], [], _, R, R).
move_follow_code_in_cases([case(Cons, Goal0)|Goals0], [case(Cons, Goal)|Goals],
Flags, R0, R) :-
move_follow_code_in_goal(Goal0, Goal, Flags, R0, R1),
move_follow_code_in_cases(Goals0, Goals, Flags, R1, R).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_in_conj(list(hlds__goal), list(hlds__goal),
pair(bool), bool, bool).
:- mode move_follow_code_in_conj(in, out, in, in, out) is det.
% Find the first branched structure, and split the
% conj into those goals before and after it.
move_follow_code_in_conj(Goals0, Goals, Flags, R0, R) :-
move_follow_code_in_conj_2(Goals0, [], RevGoals, Flags, R0, R),
list__reverse(RevGoals, Goals).
:- pred move_follow_code_in_conj_2(list(hlds__goal), list(hlds__goal),
list(hlds__goal), pair(bool), bool, bool).
:- mode move_follow_code_in_conj_2(in, in, out, in, in, out) is det.
move_follow_code_in_conj_2([], RevPrevGoals, RevPrevGoals, _, R, R).
move_follow_code_in_conj_2([Goal0 | Goals0], RevPrevGoals0, RevPrevGoals,
Flags, R0, R) :-
Flags = PushFollowCode - PushPrevCode,
(
PushFollowCode = yes,
Goal0 = GoalExpr0 - _,
goal_util__goal_is_branched(GoalExpr0),
move_follow_code_select(Goals0, FollowGoals, RestGoalsPrime),
FollowGoals \= [],
move_follow_code_move_goals(Goal0, FollowGoals, Goal1Prime)
->
R1 = yes,
Goal1 = Goal1Prime,
RestGoals = RestGoalsPrime
;
R1 = R0,
Goal1 = Goal0,
RestGoals = Goals0
),
(
PushPrevCode = yes
->
move_prev_code_forbidden_vars(RestGoals, ForbiddenVars),
move_prev_code(Goal1, Goal2, ForbiddenVars,
RevPrevGoals0, RevPrevGoals1, R1, R2)
;
RevPrevGoals1 = RevPrevGoals0,
Goal2 = Goal1,
R2 = R1
),
move_follow_code_in_goal(Goal2, Goal, Flags, R2, R3),
RevPrevGoals2 = [Goal | RevPrevGoals1],
move_follow_code_in_conj_2(RestGoals, RevPrevGoals2, RevPrevGoals,
Flags, R3, R).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_select(list(hlds__goal), list(hlds__goal),
list(hlds__goal)).
:- mode move_follow_code_select(in, out, out) is det.
move_follow_code_select([], [], []).
move_follow_code_select([Goal|Goals], FollowGoals, RestGoals) :-
(
move_follow_code_is_builtin(Goal)
->
move_follow_code_select(Goals, FollowGoals0, RestGoals),
FollowGoals = [Goal|FollowGoals0]
;
FollowGoals = [],
RestGoals = [Goal|Goals]
).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_move_goals(hlds__goal, list(hlds__goal), hlds__goal).
:- mode move_follow_code_move_goals(in, in, out) is semidet.
move_follow_code_move_goals(Goal0 - GoalInfo, FollowGoals, Goal - GoalInfo) :-
(
Goal0 = switch(Var, Det, Cases0, FV),
move_follow_code_move_goals_cases(Cases0, FollowGoals, Cases),
Goal = switch(Var, Det, Cases, FV)
;
Goal0 = disj(Goals0, FV),
move_follow_code_move_goals_disj(Goals0, FollowGoals, Goals),
Goal = disj(Goals, FV)
;
Goal0 = if_then_else(Vars, Cond, Then0, Else0, FV),
conjoin_goal_and_goal_list(Then0, FollowGoals, Then),
conjoin_goal_and_goal_list(Else0, FollowGoals, Else),
Goal = if_then_else(Vars, Cond, Then, Else, FV)
).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_move_goals_cases(list(case), list(hlds__goal),
list(case)).
:- mode move_follow_code_move_goals_cases(in, in, out) is semidet.
move_follow_code_move_goals_cases([], _FollowGoals, []).
move_follow_code_move_goals_cases([Case0|Cases0], FollowGoals, [Case|Cases]) :-
Case0 = case(Cons, Goal0),
conjoin_goal_and_goal_list(Goal0, FollowGoals, Goal),
Case = case(Cons, Goal),
move_follow_code_move_goals_cases(Cases0, FollowGoals, Cases).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_move_goals_disj(list(hlds__goal), list(hlds__goal),
list(hlds__goal)).
:- mode move_follow_code_move_goals_disj(in, in, out) is semidet.
move_follow_code_move_goals_disj([], _FollowGoals, []).
move_follow_code_move_goals_disj([Goal0|Goals0], FollowGoals, [Goal|Goals]) :-
conjoin_goal_and_goal_list(Goal0, FollowGoals, Goal),
move_follow_code_move_goals_disj(Goals0, FollowGoals, Goals).
%-----------------------------------------------------------------------------%
% Takes a goal and a list of goals, and conjoins them
% (with a potentially blank goal_info).
:- pred conjoin_goal_and_goal_list(hlds__goal, list(hlds__goal),
hlds__goal).
:- mode conjoin_goal_and_goal_list(in, in, out) is semidet.
conjoin_goal_and_goal_list(Goal0, FollowGoals, Goal) :-
Goal0 = GoalExpr0 - GoalInfo0,
goal_info_get_determinism(GoalInfo0, Detism0),
determinism_components(Detism0, CanFail0, MaxSolns0),
check_follow_code_detism(FollowGoals, CanFail0, MaxSolns0),
( GoalExpr0 = conj(GoalList0) ->
list__append(GoalList0, FollowGoals, GoalList),
GoalExpr = conj(GoalList)
;
GoalExpr = conj([Goal0 | FollowGoals])
),
Goal = GoalExpr - GoalInfo0.
% This check is necessary to make sure that follow_code
% doesn't change the determinism of the goal.
:- pred check_follow_code_detism(list(hlds__goal), can_fail, soln_count).
:- mode check_follow_code_detism(in, in, in) is semidet.
check_follow_code_detism([], _, _).
check_follow_code_detism([_ - GoalInfo | Goals], CanFail0, MaxSolns0) :-
goal_info_get_determinism(GoalInfo, Detism1),
determinism_components(Detism1, CanFail1, MaxSolns1),
det_conjunction_maxsoln(MaxSolns0, MaxSolns1, MaxSolns0),
det_conjunction_canfail(CanFail0, CanFail1, CanFail0),
check_follow_code_detism(Goals, CanFail0, MaxSolns0).
%-----------------------------------------------------------------------------%
:- pred move_follow_code_is_builtin(hlds__goal).
:- mode move_follow_code_is_builtin(in) is semidet.
move_follow_code_is_builtin(unify(_,_,_,Unification,_) - _GoalInfo) :-
Unification \= complicated_unify(_, _, _).
move_follow_code_is_builtin(call(_,_,_,Builtin, _, _, _) - _GoalInfo) :-
hlds__is_builtin_is_inline(Builtin).
%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%
:- pred move_prev_code(hlds__goal, hlds__goal, set(var),
list(hlds__goal), list(hlds__goal), bool, bool).
% :- mode move_prev_code(di, uo, in, di, uo, in, out) is det.
:- mode move_prev_code(in, out, in, in, out, in, out) is det.
move_prev_code(Goal, Goal, _, RevPrevGoals, RevPrevGoals, R, R).
% move_prev_code(Goal0, Goal, ForbiddenVars0, RevPrevGoals0, RevPrevGoals,
% R0, R) :-
% (
% move_prev_code_breakup_branched(Goal0, Cond0, First0, Rest0)
% ->
% move_prev_code_new_forbidden_vars(Cond0, First0,
% ForbiddenVars0, ForbiddenVars1),
% (
% move_prev_code_vars_difference(Cond0, First0, Rest0,
% ForbiddenVars0, LocalVars),
% move_prev_code_can_pull_producer(LocalVars, Producers,
% RevPrevGoals0, RevPrevGoals1)
% ->
% move_prev_code(Rest0, Rest, ForbiddenVars1,
% RevPrevGoals1, RevPrevGoals, R0, R),
% move_prev_code_replace_first(Goal0,
% Producers, Rest, Goal)
% ;
% move_prev_code(Rest0, Rest, ForbiddenVars1,
% RevPrevGoals0, RevPrevGoals, R0, R)
% )
% ;
% R = R0,
% Goal = Goal0,
% RevPrevGoals = [Goal0 | RevPrevGoals0]
% ).
%
% :- pred move_prev_code_breakup_branched(hlds__goal, hlds__goal, hlds__goal,
% hlds__goal).
% :- mode move_prev_code_breakup_branched(in, out, out, out) is semidet.
:- pred move_prev_code_forbidden_vars(list(hlds__goal), set(var)).
:- mode move_prev_code_forbidden_vars(in, out) is det.
move_prev_code_forbidden_vars([], Empty) :-
set__init(Empty).
move_prev_code_forbidden_vars([_Goal - GoalInfo | Goals], Varset) :-
move_prev_code_forbidden_vars(Goals, Varset0),
goal_info_get_nonlocals(GoalInfo, NonLocals),
set__union(Varset0, NonLocals, Varset).
%
% :- pred move_prev_code_new_forbidden_vars(hlds__goal, hlds__goal,
% set(var), set(var)).
% :- mode move_prev_code_new_forbidden_vars(in, in, in, out) is det.
%
% :- pred move_prev_code_vars_difference(hlds__goal, hlds__goal, hlds__goal,
% set(var), set(var)).
% :- mode move_prev_code_vars_difference(in, in, in, in, out) is det.
%
% move_prev_code_vars_difference(Cond, First, Rest, ForbiddenVars, LocalVars) :-
% Cond = _ - CondInfo,
% First = _ - FirstInfo,
% Rest = _ - RestInfo,
% goal_info_get_nonlocals(CondInfo, CondVars),
% goal_info_get_nonlocals(FirstInfo, FirstVars),
% goal_info_get_nonlocals(RestInfo, RestVars),
% set__union(CondVars, FirstVars, ThisBranchVars),
% set__difference(ThisBranchVars, RestVars, LocalVars0),
% set__difference(LocalVars0, ForbiddenVars, LocalVars).
%
% :- pred move_prev_code_can_pull_producer(set(var), list(hlds__goal),
% list(hlds__goal), list(hlds__goal)).
% :- mode move_prev_code_can_pull_producer(in, in, di, uo) is det.
%
% :- pred move_prev_code_replace_first(hlds__goal,
% list(hlds__goal), list(hlds__goal), hlds__goal).
% :- mode move_prev_code_replace_first(di, in, in, uo) is det.