void
expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
{
if (!e1 || !e2 || e1->type != e2->type)
return;
__expr_eliminate_eq(e1->type, ep1, ep2);
e1 = expr_eliminate_yn(e1);
e2 = expr_eliminate_yn(e2);
}
struct expr *expr_extract_eq_or(struct expr **ep1, struct expr **ep2)
{
struct expr *tmp = NULL;
expr_extract_eq(E_OR, &tmp, ep1, ep2);
if (tmp) {
*ep1 = expr_eliminate_yn(*ep1);
*ep2 = expr_eliminate_yn(*ep2);
}
return tmp;
}
struct expr *
expr_eliminate_dups(struct expr *e)
{
int oldcount;
if (!e)
return e;
oldcount = trans_count;
while (1) {
trans_count = 0;
switch (e->type) {
case E_OR:
case E_AND:
expr_eliminate_dups1(e->type, &e, &e);
expr_eliminate_dups2(e->type, &e, &e);
default:
;
}
if (!trans_count)
break;
e = expr_eliminate_yn(e);
}
trans_count = oldcount;
return e;
}
void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
{
if (!e1 || !e2)
return;
switch (e1->type) {
case E_OR:
case E_AND:
__expr_eliminate_eq(e1->type, ep1, ep2);
default:
;
}
if (e1->type != e2->type) switch (e2->type) {
case E_OR:
case E_AND:
__expr_eliminate_eq(e2->type, ep1, ep2);
default:
;
}
e1 = expr_eliminate_yn(e1);
e2 = expr_eliminate_yn(e2);
}
struct expr *expr_eliminate_yn(struct expr *e)
{
struct expr *tmp;
if (e) switch (e->type) {
case E_AND:
e->left.expr = expr_eliminate_yn(e->left.expr);
e->right.expr = expr_eliminate_yn(e->right.expr);
if (e->left.expr->type == E_SYMBOL) {
if (e->left.expr->left.sym == &symbol_no) {
expr_free(e->left.expr);
expr_free(e->right.expr);
e->type = E_SYMBOL;
e->left.sym = &symbol_no;
e->right.expr = NULL;
return e;
} else if (e->left.expr->left.sym == &symbol_yes) {
free(e->left.expr);
tmp = e->right.expr;
*e = *(e->right.expr);
free(tmp);
return e;
}
}
if (e->right.expr->type == E_SYMBOL) {
if (e->right.expr->left.sym == &symbol_no) {
expr_free(e->left.expr);
expr_free(e->right.expr);
e->type = E_SYMBOL;
e->left.sym = &symbol_no;
e->right.expr = NULL;
return e;
} else if (e->right.expr->left.sym == &symbol_yes) {
free(e->right.expr);
tmp = e->left.expr;
*e = *(e->left.expr);
free(tmp);
return e;
}
}
break;
case E_OR:
e->left.expr = expr_eliminate_yn(e->left.expr);
e->right.expr = expr_eliminate_yn(e->right.expr);
if (e->left.expr->type == E_SYMBOL) {
if (e->left.expr->left.sym == &symbol_no) {
free(e->left.expr);
tmp = e->right.expr;
*e = *(e->right.expr);
free(tmp);
return e;
} else if (e->left.expr->left.sym == &symbol_yes) {
expr_free(e->left.expr);
expr_free(e->right.expr);
e->type = E_SYMBOL;
e->left.sym = &symbol_yes;
e->right.expr = NULL;
return e;
}
}
if (e->right.expr->type == E_SYMBOL) {
if (e->right.expr->left.sym == &symbol_no) {
free(e->right.expr);
tmp = e->left.expr;
*e = *(e->left.expr);
free(tmp);
return e;
} else if (e->right.expr->left.sym == &symbol_yes) {
expr_free(e->left.expr);
expr_free(e->right.expr);
e->type = E_SYMBOL;
e->left.sym = &symbol_yes;
e->right.expr = NULL;
return e;
}
}
break;
default:
;
}
return e;
}
