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%---------------------------------------------------------------------------%
% Copyright (C) 1997-1999 The 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.
%---------------------------------------------------------------------------%
%
% file: const_prop.m
% main author: conway.
%
% This module provides the facility to evaluate calls at compile time -
% transforming them to simpler goals such as construction unifications.
%
% XXX We should check for overflow.
% XXX Some of this code should be shared with vn_util__simplify_vnrval.
%
%------------------------------------------------------------------------------%
:- module const_prop.
:- interface.
:- import_module hlds_module, hlds_goal, hlds_pred, prog_data, instmap.
:- import_module list.
:- pred evaluate_builtin(pred_id, proc_id, list(prog_var), hlds_goal_info,
hlds_goal_expr, hlds_goal_info, instmap,
module_info, module_info).
:- mode evaluate_builtin(in, in, in, in, out, out, in, in, out) is semidet.
%------------------------------------------------------------------------------%
:- implementation.
:- import_module code_aux, det_analysis, follow_code, goal_util.
:- import_module hlds_goal, hlds_data, instmap, inst_match.
:- import_module globals, options, passes_aux, prog_data, mode_util, type_util.
:- import_module code_util, quantification, modes.
:- import_module bool, list, int, float, map, require.
:- import_module (inst), hlds_out, std_util.
%------------------------------------------------------------------------------%
evaluate_builtin(PredId, ProcId, Args, GoalInfo0, Goal, GoalInfo,
InstMap, ModuleInfo0, ModuleInfo) :-
predicate_module(ModuleInfo0, PredId, ModuleName),
predicate_name(ModuleInfo0, PredId, PredName),
proc_id_to_int(ProcId, ProcInt),
LookupVarInsts = lambda([V::in, J::out] is det, (
instmap__lookup_var(InstMap, V, VInst),
J = V - VInst
)),
list__map(LookupVarInsts, Args, ArgInsts),
evaluate_builtin_2(ModuleName, PredName, ProcInt, ArgInsts, GoalInfo0,
Goal, GoalInfo, ModuleInfo0, ModuleInfo).
:- pred evaluate_builtin_2(module_name, string, int,
list(pair(prog_var, (inst))), hlds_goal_info, hlds_goal_expr,
hlds_goal_info, module_info, module_info).
:- mode evaluate_builtin_2(in, in, in, in, in, out, out, in, out) is semidet.
% Module_info is not actually used at the moment.
evaluate_builtin_2(Module, Pred, ModeNum, Args, GoalInfo0, Goal, GoalInfo,
ModuleInfo, ModuleInfo) :-
% -- not yet:
% Module = qualified(unqualified("std"), Mod),
Module = unqualified(Mod),
(
Args = [X, Y],
evaluate_builtin_bi(Mod, Pred, ModeNum, X, Y, W, Cons)
->
make_construction(W, Cons, Goal),
goal_info_get_instmap_delta(GoalInfo0, Delta0),
W = Var - _WInst,
instmap_delta_set(Delta0, Var,
bound(unique, [functor(Cons, [])]), Delta),
goal_info_set_instmap_delta(GoalInfo0, Delta, GoalInfo)
;
Args = [X, Y, Z],
evaluate_builtin_tri(Mod, Pred, ModeNum, X, Y, Z, W, Cons)
->
make_construction(W, Cons, Goal),
goal_info_get_instmap_delta(GoalInfo0, Delta0),
W = Var - _WInst,
instmap_delta_set(Delta0, Var,
bound(unique, [functor(Cons, [])]), Delta),
goal_info_set_instmap_delta(GoalInfo0, Delta, GoalInfo)
;
evaluate_builtin_test(Mod, Pred, ModeNum, Args, Result)
->
make_true_or_fail(Result, GoalInfo0, Goal, GoalInfo)
;
fail
).
%------------------------------------------------------------------------------%
:- pred evaluate_builtin_bi(string, string, int,
pair(prog_var, (inst)), pair(prog_var, (inst)),
pair(prog_var, (inst)), cons_id).
:- mode evaluate_builtin_bi(in, in, in, in, in, out, out) is semidet.
% Integer arithmetic
evaluate_builtin_bi("int", "+", 0, X, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
ZVal is XVal.
evaluate_builtin_bi("int", "-", 0, X, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
ZVal is -XVal.
evaluate_builtin_bi("int", "\\", 0, X, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
ZVal is \ XVal.
% Floating point arithmetic
evaluate_builtin_bi("float", "+", 0, X, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
ZVal is XVal.
evaluate_builtin_bi("float", "-", 0, X, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
ZVal is -XVal.
%------------------------------------------------------------------------------%
:- pred evaluate_builtin_tri(string, string, int,
pair(prog_var, (inst)), pair(prog_var, (inst)),
pair(prog_var, (inst)), pair(prog_var, (inst)), cons_id).
:- mode evaluate_builtin_tri(in, in, in, in, in, in, out, out) is semidet.
%
% Integer arithmetic
%
evaluate_builtin_tri("int", "+", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is XVal + YVal.
evaluate_builtin_tri("int", "+", 1, X, Y, Z, X, int_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
XVal is ZVal - YVal.
evaluate_builtin_tri("int", "+", 2, X, Y, Z, Y, int_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
YVal is ZVal - XVal.
evaluate_builtin_tri("int", "-", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is XVal - YVal.
evaluate_builtin_tri("int", "-", 1, X, Y, Z, X, int_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
XVal is YVal + ZVal.
evaluate_builtin_tri("int", "-", 2, X, Y, Z, Y, int_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
YVal is XVal - ZVal.
evaluate_builtin_tri("int", "*", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is XVal * YVal.
/****
evaluate_builtin_tri("int", "*", 1, X, Y, Z, X, int_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
YVal \= 0,
XVal is ZVal // YVal.
evaluate_builtin_tri("int", "*", 2, X, Y, Z, Y, int_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
XVal \= 0,
YVal is ZVal // XVal.
****/
evaluate_builtin_tri("int", "//", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
YVal \= 0,
ZVal is XVal // YVal.
/****
evaluate_builtin_tri("int", "//", 1, X, Y, Z, X, int_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
XVal is ZVal * YVal.
evaluate_builtin_tri("int", "//", 2, X, Y, Z, Y, int_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(int_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
ZVal \= 0,
YVal is XVal // ZVal.
****/
% This isn't actually a builtin.
evaluate_builtin_tri("int", "mod", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
YVal \= 0,
ZVal is XVal mod YVal.
evaluate_builtin_tri("int", "rem", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
YVal \= 0,
ZVal is XVal rem YVal.
evaluate_builtin_tri("int", "unchecked_left_shift",
0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is unchecked_left_shift(XVal, YVal).
% This isn't actually a builtin.
evaluate_builtin_tri("int", "<<", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is XVal << YVal.
evaluate_builtin_tri("int", "unchecked_right_shift",
0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is unchecked_right_shift(XVal, YVal).
% This isn't actually a builtin.
evaluate_builtin_tri("int", ">>", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is XVal >> YVal.
evaluate_builtin_tri("int", "/\\", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is XVal /\ YVal.
evaluate_builtin_tri("int", "\\/", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal is XVal \/ YVal.
evaluate_builtin_tri("int", "^", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal = XVal `xor` YVal.
evaluate_builtin_tri("int", "xor", 0, X, Y, Z, Z, int_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
ZVal = XVal `xor` YVal.
%
% float arithmetic
%
evaluate_builtin_tri("float", "+", 0, X, Y, Z, Z, float_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
ZVal is XVal + YVal.
evaluate_builtin_tri("float", "+", 1, X, Y, Z, X, float_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
XVal is ZVal - YVal.
evaluate_builtin_tri("float", "+", 2, X, Y, Z, Y, float_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
YVal is ZVal - XVal.
evaluate_builtin_tri("float", "-", 0, X, Y, Z, Z, float_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
ZVal is XVal - YVal.
evaluate_builtin_tri("float", "-", 1, X, Y, Z, X, float_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
XVal is YVal + ZVal.
evaluate_builtin_tri("float", "-", 2, X, Y, Z, Y, float_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
YVal is XVal - ZVal.
evaluate_builtin_tri("float", "*", 0, X, Y, Z, Z, float_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
ZVal is XVal * YVal.
evaluate_builtin_tri("float", "*", 1, X, Y, Z, X, float_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
YVal \= 0.0,
XVal is ZVal / YVal.
evaluate_builtin_tri("float", "*", 2, X, Y, Z, Y, float_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
XVal \= 0.0,
YVal is ZVal / XVal.
evaluate_builtin_tri("float", "//", 0, X, Y, Z, Z, float_const(ZVal)) :-
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
YVal \= 0.0,
ZVal is XVal / YVal.
evaluate_builtin_tri("float", "//", 1, X, Y, Z, X, float_const(XVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
XVal is ZVal * YVal.
evaluate_builtin_tri("float", "//", 2, X, Y, Z, Y, float_const(YVal)) :-
Z = _ZVar - bound(_ZUniq, [functor(float_const(ZVal), [])]),
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
ZVal \= 0.0,
YVal is XVal / ZVal.
%------------------------------------------------------------------------------%
:- pred evaluate_builtin_test(string, string, int,
list(pair(prog_var, inst)), bool).
:- mode evaluate_builtin_test(in, in, in, in, out) is semidet.
% Integer comparisons
evaluate_builtin_test("int", "<", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
( XVal < YVal ->
Result = yes
;
Result = no
).
evaluate_builtin_test("int", "=<", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
( XVal =< YVal ->
Result = yes
;
Result = no
).
evaluate_builtin_test("int", ">", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
( XVal > YVal ->
Result = yes
;
Result = no
).
evaluate_builtin_test("int", ">=", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(int_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(int_const(YVal), [])]),
( XVal >= YVal ->
Result = yes
;
Result = no
).
% Float comparisons
evaluate_builtin_test("float", "<", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
( XVal < YVal ->
Result = yes
;
Result = no
).
evaluate_builtin_test("float", "=<", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
( XVal =< YVal ->
Result = yes
;
Result = no
).
evaluate_builtin_test("float", ">", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
( XVal > YVal ->
Result = yes
;
Result = no
).
evaluate_builtin_test("float", ">=", 0, Args, Result) :-
Args = [X, Y],
X = _XVar - bound(_XUniq, [functor(float_const(XVal), [])]),
Y = _YVar - bound(_YUniq, [functor(float_const(YVal), [])]),
( XVal >= YVal ->
Result = yes
;
Result = no
).
%------------------------------------------------------------------------------%
% recompute_instmap_delta is run by simplify.m if anything changes,
% so the insts are not important here.
:- pred make_construction(pair(prog_var, inst), cons_id, hlds_goal_expr).
:- mode make_construction(in, in, out) is det.
make_construction(Var - _, ConsId, Goal) :-
make_const_construction(Var, ConsId, Goal - _).
%------------------------------------------------------------------------------%
:- pred make_true_or_fail(bool, hlds_goal_info, hlds_goal_expr, hlds_goal_info).
:- mode make_true_or_fail(in, in, out, out) is det.
make_true_or_fail(yes, GoalInfo, conj([]), GoalInfo).
make_true_or_fail(no, GoalInfo, disj([], SM), GoalInfo) :-
map__init(SM).
%------------------------------------------------------------------------------%
|
