2 #include <bernstein/bernstein.h>
3 #include <bernstein/piecewise_lst.h>
4 #include <barvinok/barvinok.h>
5 #include <barvinok/util.h>
6 #include <barvinok/bernstein.h>
7 #include <barvinok/options.h>
10 using namespace bernstein
;
19 ex
evalue2ex(evalue
*e
, const exvector
& vars
)
21 if (value_notzero_p(e
->d
))
22 return value2numeric(e
->x
.n
)/value2numeric(e
->d
);
23 if (e
->x
.p
->type
!= polynomial
)
26 for (int i
= e
->x
.p
->size
-1; i
>= 0; --i
) {
27 poly
*= vars
[e
->x
.p
->pos
-1];
28 ex t
= evalue2ex(&e
->x
.p
->arr
[i
], vars
);
29 if (is_exactly_a
<fail
>(t
))
36 static int type_offset(enode
*p
)
38 return p
->type
== fractional
? 1 :
39 p
->type
== flooring
? 1 : 0;
42 typedef pair
<bool, const evalue
*> typed_evalue
;
44 static ex
evalue2ex_add_var(evalue
*e
, exvector
& extravar
,
45 vector
<typed_evalue
>& expr
, bool is_fract
)
49 for (int i
= 0; i
< expr
.size(); ++i
) {
50 if (is_fract
== expr
[i
].first
&& eequal(e
, expr
[i
].second
)) {
51 base_var
= extravar
[i
];
59 snprintf(name
, sizeof(name
), "f%c%d", is_fract
? 'r' : 'l', expr
.size());
60 extravar
.push_back(base_var
= symbol(name
));
61 expr
.push_back(typed_evalue(is_fract
, e
));
66 /* For the argument e=(f/d) of a fractional, return (d-1)/d times
67 * a variable in [0,1] (see setup_constraints).
69 static ex
evalue2ex_get_fract(evalue
*e
, exvector
& extravar
,
70 vector
<typed_evalue
>& expr
)
78 den
= value2numeric(d
);
82 ex base_var
= evalue2ex_add_var(e
, extravar
, expr
, true);
87 static ex
evalue2ex_r(const evalue
*e
, const exvector
& vars
,
88 exvector
& extravar
, vector
<typed_evalue
>& expr
,
91 if (value_notzero_p(e
->d
))
92 return value2numeric(e
->x
.n
)/value2numeric(e
->d
);
96 switch (e
->x
.p
->type
) {
98 base_var
= vars
[e
->x
.p
->pos
-1];
101 base_var
= evalue2ex_add_var(&e
->x
.p
->arr
[0], extravar
, expr
, false);
104 base_var
= evalue2ex_get_fract(&e
->x
.p
->arr
[0], extravar
, expr
);
108 return evalue2ex_r(&e
->x
.p
->arr
[VALUE_TO_INT(coset
->p
[e
->x
.p
->pos
-1])],
109 vars
, extravar
, expr
, coset
);
114 int offset
= type_offset(e
->x
.p
);
115 for (int i
= e
->x
.p
->size
-1; i
>= offset
; --i
) {
117 ex t
= evalue2ex_r(&e
->x
.p
->arr
[i
], vars
, extravar
, expr
, coset
);
118 if (is_exactly_a
<fail
>(t
))
125 /* For each t = floor(e/d), set up two constraints
128 * -e + d t + d-1 >= 0
130 * e is assumed to be an affine expression.
132 * For each t = fract(e/d), set up two constraints
137 static Matrix
*setup_constraints(const vector
<typed_evalue
> expr
, int nvar
)
139 int extra
= expr
.size();
142 Matrix
*M
= Matrix_Alloc(2*extra
, 1+extra
+nvar
+1);
143 for (int i
= 0; i
< extra
; ++i
) {
145 value_set_si(M
->p
[2*i
][0], 1);
146 value_set_si(M
->p
[2*i
][1+i
], -1);
147 value_set_si(M
->p
[2*i
][1+extra
+nvar
], 1);
148 value_set_si(M
->p
[2*i
+1][0], 1);
149 value_set_si(M
->p
[2*i
+1][1+i
], 1);
151 Value
*d
= &M
->p
[2*i
][1+i
];
153 evalue_denom(expr
[i
].second
, d
);
155 for (e
= expr
[i
].second
; value_zero_p(e
->d
); e
= &e
->x
.p
->arr
[0]) {
156 assert(e
->x
.p
->type
== polynomial
);
157 assert(e
->x
.p
->size
== 2);
158 evalue
*c
= &e
->x
.p
->arr
[1];
159 value_multiply(M
->p
[2*i
][1+extra
+e
->x
.p
->pos
-1], *d
, c
->x
.n
);
160 value_division(M
->p
[2*i
][1+extra
+e
->x
.p
->pos
-1],
161 M
->p
[2*i
][1+extra
+e
->x
.p
->pos
-1], c
->d
);
163 value_multiply(M
->p
[2*i
][1+extra
+nvar
], *d
, e
->x
.n
);
164 value_division(M
->p
[2*i
][1+extra
+nvar
], M
->p
[2*i
][1+extra
+nvar
], e
->d
);
165 value_oppose(*d
, *d
);
166 value_set_si(M
->p
[2*i
][0], -1);
167 Vector_Scale(M
->p
[2*i
], M
->p
[2*i
+1], M
->p
[2*i
][0], 1+extra
+nvar
+1);
168 value_set_si(M
->p
[2*i
][0], 1);
169 value_subtract(M
->p
[2*i
+1][1+extra
+nvar
], M
->p
[2*i
+1][1+extra
+nvar
], *d
);
170 value_decrement(M
->p
[2*i
+1][1+extra
+nvar
], M
->p
[2*i
+1][1+extra
+nvar
]);
176 static bool evalue_is_periodic(const evalue
*e
, Vector
*periods
)
179 bool is_periodic
= false;
181 if (value_notzero_p(e
->d
))
184 assert(e
->x
.p
->type
!= partition
);
185 if (e
->x
.p
->type
== periodic
) {
188 value_set_si(size
, e
->x
.p
->size
);
189 value_lcm(periods
->p
[e
->x
.p
->pos
-1], size
, &periods
->p
[e
->x
.p
->pos
-1]);
193 offset
= type_offset(e
->x
.p
);
194 for (i
= e
->x
.p
->size
-1; i
>= offset
; --i
)
195 is_periodic
= evalue_is_periodic(&e
->x
.p
->arr
[i
], periods
) || is_periodic
;
199 static ex
evalue2lst(const evalue
*e
, const exvector
& vars
,
200 exvector
& extravar
, vector
<typed_evalue
>& expr
,
203 Vector
*coset
= Vector_Alloc(periods
->Size
);
207 list
.append(evalue2ex_r(e
, vars
, extravar
, expr
, coset
));
208 for (i
= coset
->Size
-1; i
>= 0; --i
) {
209 value_increment(coset
->p
[i
], coset
->p
[i
]);
210 if (value_lt(coset
->p
[i
], periods
->p
[i
]))
212 value_set_si(coset
->p
[i
], 0);
221 ex
evalue2ex(const evalue
*e
, const exvector
& vars
, exvector
& floorvar
,
222 Matrix
**C
, Vector
**p
)
224 vector
<typed_evalue
> expr
;
225 Vector
*periods
= Vector_Alloc(vars
.size());
228 for (int i
= 0; i
< periods
->Size
; ++i
)
229 value_set_si(periods
->p
[i
], 1);
230 if (evalue_is_periodic(e
, periods
)) {
236 Vector_Free(periods
);
238 ex poly
= evalue2ex_r(e
, vars
, floorvar
, expr
, NULL
);
239 Matrix
*M
= setup_constraints(expr
, vars
.size());
245 /* if the evalue is a relation, we use the relation to cut off the
246 * the edges of the domain
248 static void evalue_extract_poly(evalue
*e
, int i
, Polyhedron
**D
, evalue
**poly
,
251 *D
= EVALUE_DOMAIN(e
->x
.p
->arr
[2*i
]);
252 *poly
= e
= &e
->x
.p
->arr
[2*i
+1];
253 if (value_notzero_p(e
->d
))
255 if (e
->x
.p
->type
!= relation
)
257 if (e
->x
.p
->size
> 2)
259 evalue
*fr
= &e
->x
.p
->arr
[0];
260 assert(value_zero_p(fr
->d
));
261 assert(fr
->x
.p
->type
== fractional
);
262 assert(fr
->x
.p
->size
== 3);
263 Matrix
*T
= Matrix_Alloc(2, (*D
)->Dimension
+1);
264 value_set_si(T
->p
[1][(*D
)->Dimension
], 1);
266 /* convert argument of fractional to polylib */
267 /* the argument is assumed to be linear */
268 evalue
*p
= &fr
->x
.p
->arr
[0];
269 evalue_denom(p
, &T
->p
[1][(*D
)->Dimension
]);
270 for (;value_zero_p(p
->d
); p
= &p
->x
.p
->arr
[0]) {
271 assert(p
->x
.p
->type
== polynomial
);
272 assert(p
->x
.p
->size
== 2);
273 assert(value_notzero_p(p
->x
.p
->arr
[1].d
));
274 int pos
= p
->x
.p
->pos
- 1;
275 value_assign(T
->p
[0][pos
], p
->x
.p
->arr
[1].x
.n
);
276 value_multiply(T
->p
[0][pos
], T
->p
[0][pos
], T
->p
[1][(*D
)->Dimension
]);
277 value_division(T
->p
[0][pos
], T
->p
[0][pos
], p
->x
.p
->arr
[1].d
);
279 int pos
= (*D
)->Dimension
;
280 value_assign(T
->p
[0][pos
], p
->x
.n
);
281 value_multiply(T
->p
[0][pos
], T
->p
[0][pos
], T
->p
[1][(*D
)->Dimension
]);
282 value_division(T
->p
[0][pos
], T
->p
[0][pos
], p
->d
);
284 Polyhedron
*E
= NULL
;
285 for (Polyhedron
*P
= *D
; P
; P
= P
->next
) {
286 Polyhedron
*I
= Polyhedron_Image(P
, T
, MaxRays
);
287 I
= DomainConstraintSimplify(I
, MaxRays
);
288 Polyhedron
*R
= Polyhedron_Preimage(I
, T
, MaxRays
);
290 Polyhedron
*next
= P
->next
;
292 Polyhedron
*S
= DomainIntersection(P
, R
, MaxRays
);
298 E
= DomainConcat(S
, E
);
303 *poly
= &e
->x
.p
->arr
[1];
306 piecewise_lst
*evalue_bernstein_coefficients(piecewise_lst
*pl_all
, evalue
*e
,
307 Polyhedron
*ctx
, const exvector
& params
)
310 barvinok_options
*options
= barvinok_options_new_with_defaults();
311 pl
= evalue_bernstein_coefficients(pl_all
, e
, ctx
, params
, options
);
312 barvinok_options_free(options
);
316 static piecewise_lst
*bernstein_coefficients(piecewise_lst
*pl_all
,
317 Polyhedron
*D
, const ex
& poly
,
319 const exvector
& params
, const exvector
& floorvar
,
320 barvinok_options
*options
)
322 if (!D
->next
&& emptyQ2(D
))
325 unsigned PP_MaxRays
= options
->MaxRays
;
326 if (PP_MaxRays
& POL_NO_DUAL
)
329 for (Polyhedron
*P
= D
; P
; P
= P
->next
) {
330 /* This shouldn't happen */
333 Param_Polyhedron
*PP
;
334 Polyhedron
*next
= P
->next
;
337 if (Polyhedron_is_unbounded(P
, ctx
->Dimension
, options
->MaxRays
)) {
338 fprintf(stderr
, "warning: unbounded domain skipped\n");
339 Polyhedron_Print(stderr
, P_VALUE_FMT
, P
);
343 PP
= Polyhedron2Param_Domain(P
, ctx
, PP_MaxRays
);
344 piecewise_lst
*pl
= new piecewise_lst(params
);
345 for (Param_Domain
*Q
= PP
->D
; Q
; Q
= Q
->next
) {
346 matrix VM
= domainVertices(PP
, Q
, params
);
347 lst coeffs
= bernsteinExpansion(VM
, poly
, floorvar
, params
);
348 pl
->list
.push_back(guarded_lst(Polyhedron_Copy(Q
->Domain
), coeffs
));
350 Param_Polyhedron_Free(PP
);
354 pl_all
->combine(*pl
);
362 /* Compute the coefficients of the polynomial corresponding to each coset
363 * on its own domain. This allows us to cut the domain on multiples of
365 * To perform the cutting for a coset "i mod n = c" we map the domain
366 * to the quotient space trough "i = i' n + c", simplify the constraints
367 * (implicitly) and then map back to the original space.
369 static piecewise_lst
*bernstein_coefficients_periodic(piecewise_lst
*pl_all
,
370 Polyhedron
*D
, const evalue
*e
,
371 Polyhedron
*ctx
, const exvector
& vars
,
372 const exvector
& params
, Vector
*periods
,
373 barvinok_options
*options
)
375 assert(D
->Dimension
== periods
->Size
);
376 Matrix
*T
= Matrix_Alloc(D
->Dimension
+1, D
->Dimension
+1);
377 Matrix
*T2
= Matrix_Alloc(D
->Dimension
+1, D
->Dimension
+1);
378 Vector
*coset
= Vector_Alloc(periods
->Size
);
380 vector
<typed_evalue
> expr
;
381 exvector allvars
= vars
;
382 allvars
.insert(allvars
.end(), params
.begin(), params
.end());
384 value_set_si(T2
->p
[D
->Dimension
][D
->Dimension
], 1);
385 for (int i
= 0; i
< D
->Dimension
; ++i
) {
386 value_assign(T
->p
[i
][i
], periods
->p
[i
]);
387 value_lcm(T2
->p
[D
->Dimension
][D
->Dimension
], periods
->p
[i
],
388 &T2
->p
[D
->Dimension
][D
->Dimension
]);
390 value_set_si(T
->p
[D
->Dimension
][D
->Dimension
], 1);
391 for (int i
= 0; i
< D
->Dimension
; ++i
)
392 value_division(T2
->p
[i
][i
], T2
->p
[D
->Dimension
][D
->Dimension
],
396 ex poly
= evalue2ex_r(e
, allvars
, extravar
, expr
, coset
);
397 assert(extravar
.size() == 0);
398 assert(expr
.size() == 0);
399 Polyhedron
*E
= DomainPreimage(D
, T
, options
->MaxRays
);
400 Polyhedron
*F
= DomainPreimage(E
, T2
, options
->MaxRays
);
403 pl_all
= bernstein_coefficients(pl_all
, F
, poly
, ctx
, params
,
406 for (i
= D
->Dimension
-1; i
>= 0; --i
) {
407 value_increment(coset
->p
[i
], coset
->p
[i
]);
408 value_increment(T
->p
[i
][D
->Dimension
], T
->p
[i
][D
->Dimension
]);
409 value_subtract(T2
->p
[i
][D
->Dimension
], T2
->p
[i
][D
->Dimension
],
411 if (value_lt(coset
->p
[i
], periods
->p
[i
]))
413 value_set_si(coset
->p
[i
], 0);
414 value_set_si(T
->p
[i
][D
->Dimension
], 0);
415 value_set_si(T2
->p
[i
][D
->Dimension
], 0);
426 piecewise_lst
*evalue_bernstein_coefficients(piecewise_lst
*pl_all
, evalue
*e
,
427 Polyhedron
*ctx
, const exvector
& params
,
428 barvinok_options
*options
)
430 unsigned nparam
= ctx
->Dimension
;
431 if (EVALUE_IS_ZERO(*e
))
433 assert(value_zero_p(e
->d
));
434 assert(e
->x
.p
->type
== partition
);
435 assert(e
->x
.p
->size
>= 2);
436 unsigned nvars
= EVALUE_DOMAIN(e
->x
.p
->arr
[0])->Dimension
- nparam
;
438 exvector vars
= constructVariableVector(nvars
, "v");
439 exvector allvars
= vars
;
440 allvars
.insert(allvars
.end(), params
.begin(), params
.end());
442 for (int i
= 0; i
< e
->x
.p
->size
/2; ++i
) {
449 evalue_extract_poly(e
, i
, &E
, &EP
, options
->MaxRays
);
450 ex poly
= evalue2ex(EP
, allvars
, floorvar
, &M
, &periods
);
451 floorvar
.insert(floorvar
.end(), vars
.begin(), vars
.end());
453 Polyhedron
*AE
= align_context(E
, M
->NbColumns
-2, options
->MaxRays
);
454 if (E
!= EVALUE_DOMAIN(e
->x
.p
->arr
[2*i
]))
456 E
= DomainAddConstraints(AE
, M
, options
->MaxRays
);
460 if (is_exactly_a
<fail
>(poly
)) {
461 if (E
!= EVALUE_DOMAIN(e
->x
.p
->arr
[2*i
]))
467 pl_all
= bernstein_coefficients_periodic(pl_all
, E
, EP
, ctx
, vars
,
468 params
, periods
, options
);
470 pl_all
= bernstein_coefficients(pl_all
, E
, poly
, ctx
, params
,
473 Vector_Free(periods
);
474 if (E
!= EVALUE_DOMAIN(e
->x
.p
->arr
[2*i
]))