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/* See LICENSE file for copyright and license details. */
#include "common.h"
#ifndef TEST
/**
* See `.inverse` in `struct libnormalform_sentence` (XOR implementation)
*/
static LIBNORMALFORM_SENTENCE *
xor_inverse(LIBNORMALFORM_SENTENCE *this)
{
/* ¬(l ⊕ r) = ¬l ⊕ r, (¬l ⊕ ¬r = l ⊕ r) */
LIBNORMALFORM_SENTENCE *l, *r, *ret;
l = this->data.binary.l->inverse(this->data.binary.l);
if (!l)
return NULL;
r = libnormalform_ref(this->data.binary.r);
if (!r) {
libnormalform_free(l);
return NULL;
}
ret = libnormalform_xor2__(l, r);
if (ret && this->atom) {
ret->atom = this->atom;
ret->atom->refcount += 1;
}
return ret;
}
/**
* See `.equals` in `struct libnormalform_sentence` (XOR implementation)
*/
static int
xor_equals(LIBNORMALFORM_SENTENCE *this, LIBNORMALFORM_SENTENCE *other, int *inv_out)
{
LIBNORMALFORM_SENTENCE *tl, *tr, *oll, *olr;
LIBNORMALFORM_SENTENCE *ol, *or, *orl, *orr;
int inv;
if (other->type != TYPE_XOR) {
int invll, invrl, invlr, invrr;
if (this->hash != other->hash)
return 0;
if (other->type != TYPE_AND && other->type != TYPE_OR)
return 0;
/* a ⊕ b = (a ∨ b) ∧ (¬a ∨ ¬b) */
/* ¬(a ⊕ b) = (a ∧ b) ∨ (¬a ∧ ¬b) */
/* ¬(a ⊕ b) = (a ∨ ¬b) ∧ (¬a ∨ b) */
/* a ⊕ b = (a ∧ ¬b) ∨ (¬a ∧ b) */
tl = this->data.binary.l;
tr = this->data.binary.r;
ol = other->data.binary.l;
or = other->data.binary.r;
if (ol->hash != or->hash)
return 0;
if (ol->type != or->type)
return 0;
if ((ol->type ^ other->type) != (TYPE_AND ^ TYPE_OR))
return 0;
oll = ol->data.binary.l;
olr = ol->data.binary.r;
orl = or->data.binary.l;
orr = or->data.binary.r;
if (!tl->equals(tl, oll, &invll)) {
oll = ol->data.binary.r;
olr = ol->data.binary.l;
if (!tl->equals(tl, oll, &invll))
return 0;
}
if (!tl->equals(tl, orl, &invrl)) {
orl = or->data.binary.r;
orr = or->data.binary.l;
if (!tl->equals(tl, orl, &invrl))
return 0;
}
if (invll == invrl)
return 0;
if (!tr->equals(tr, olr, &invlr))
return 0;
if (!tr->equals(tr, orr, &invrr))
return 0;
if (invlr == invrr)
return 0;
*inv_out = (invll == invlr) == (other->type == TYPE_OR);
return 1;
}
tl = this->data.binary.l;
tr = this->data.binary.r;
ol = other->data.binary.l;
or = other->data.binary.r;
if (tl->hash != ol->hash || tr->hash != or->hash)
return 0;
if (!tl->equals(tl, ol, inv_out)) {
if (tl->hash == tr->hash) {
ol = other->data.binary.r;
or = other->data.binary.l;
if (!tl->equals(tl, ol, inv_out))
return 0;
} else {
return 0;
}
}
if (!tr->equals(tr, or, &inv))
return 0;
*inv_out ^= inv;
return 1;
}
/**
* See `.evaluate` in `struct libnormalform_sentence` (XOR implementation)
*/
static int
xor_evaluate(LIBNORMALFORM_SENTENCE *this, void *input)
{
int l, r;
l = this->data.binary.l->evaluate(this->data.binary.l, input);
if (l < 0)
return l;
r = this->data.binary.r->evaluate(this->data.binary.r, input);
if (r < 0)
return r;
return l ^ r;
}
LIBNORMALFORM_SENTENCE *
(libnormalform_xor2__)(LIBNORMALFORM_SENTENCE *l, LIBNORMALFORM_SENTENCE *r)
{
static const struct libnormalform_sentence prototype = {
PROTOTYPE_COMMON,
.type = TYPE_XOR,
.inverse = &xor_inverse,
.equals = &xor_equals,
.evaluate = &xor_evaluate
};
LIBNORMALFORM_SENTENCE *ret = malloc(sizeof(*ret));
if (!ret) {
libnormalform_free(l);
libnormalform_free(r);
return NULL;
}
*ret = prototype;
ret->hash = XOR_HASH(l, r);
if (l->hash <= r->hash) {
ret->data.binary.l = l;
ret->data.binary.r = r;
} else {
ret->data.binary.l = r;
ret->data.binary.r = l;
}
return ret;
}
#else
CONST int
main(void)
{
return 0; /* indirectly tested */
}
#endif
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