integer *
integer_suba(integer * data, integer * y)
{
int cmp;
integer *q = NULL;
if (y->len_of_integer == 0)
return data;
if (data->len_of_integer == 0)
{
integer_assign(data, y);
return data;
}
cmp = integer_abscmp(data, y);
if (cmp == 0 && data->sign_of_integer == y->sign_of_integer)
{
integer_clear(data);
return data;
}
if (cmp == 0 && data->sign_of_integer != y->sign_of_integer)
{
integer_lshifta(data, 1);
return data;
}
if (cmp == 1 && data->sign_of_integer == y->sign_of_integer)
{
integer_ssub(data, y);
return data;
}
if (cmp == 1 && data->sign_of_integer != y->sign_of_integer)
{
integer_sadd(data, y);
return data;
}
if (cmp == -1 && data->sign_of_integer == y->sign_of_integer)
{
q = integer_copy(data);
integer_assign(data, y);
data->sign_of_integer = !data->sign_of_integer;
integer_ssub(data, q);
integer_destroy(q);
return data;
}
if (cmp == -1 && data->sign_of_integer == y->sign_of_integer)
{
integer_sadd(data, y);
return data;
}
return data;
}
void coefficient_pp_cont(const lp_polynomial_context_t* ctx, coefficient_t* pp, coefficient_t* cont, const coefficient_t* C) {
TRACE("coefficient", "coefficient_pp_cont()\n");
STAT(coefficient, pp_cont) ++;
if (trace_is_enabled("coefficient")) {
tracef("C = "); coefficient_print(ctx, C, trace_out); tracef("\n");
}
assert(ctx->K == lp_Z);
int special = coefficient_pp_cont_special(ctx, pp, cont, C);
if (special) {
return;
}
switch (C->type) {
case COEFFICIENT_NUMERIC:
if (cont) {
if (cont->type == COEFFICIENT_POLYNOMIAL) {
coefficient_destruct(cont);
coefficient_construct_copy(ctx, cont, C);
} else {
integer_assign(ctx->K, &cont->value.num, &C->value.num);
}
}
if (pp) {
if (pp->type == COEFFICIENT_POLYNOMIAL) {
coefficient_destruct(pp);
coefficient_construct_from_int(ctx, pp, 1);
} else {
integer_assign_int(ctx->K, &pp->value.num, 1);
}
}
break;
case COEFFICIENT_POLYNOMIAL:
{
int i;
coefficient_t gcd;
// Compute the gcd of coefficients starting with LC
coefficient_construct_copy(ctx, &gcd, coefficient_lc(C));
// Make if positive in case it's the only one
if (coefficient_lc_sgn(ctx, &gcd) < 0) {
coefficient_neg(ctx, &gcd, &gcd);
}
// Compute the rest of the gcd
for (i = SIZE(C)-2; i >= 0 ; -- i) {
if (!coefficient_is_zero(ctx, COEFF(C, i))) {
coefficient_gcd(ctx, &gcd, &gcd, COEFF(C, i));
if (coefficient_is_one(ctx, &gcd)) {
break;
}
}
}
// GCD is positive, so if the leading coefficient of C is negative, flip it
if (coefficient_lc_sgn(ctx, C) < 0) {
coefficient_neg(ctx, &gcd, &gcd);
}
if (pp) {
// Now compute the pp
coefficient_div(ctx, pp, C, &gcd);
assert(coefficient_is_normalized(ctx, pp));
}
if (cont) {
coefficient_swap(&gcd, cont);
assert(coefficient_is_normalized(ctx, cont));
}
coefficient_destruct(&gcd);
break;
}
default:
assert(0);
break;
}
if (trace_is_enabled("coefficient")) {
tracef("coefficient_pp_cont() => ");
if (pp) { tracef("pp = "); coefficient_print(ctx, pp, trace_out); tracef("\n"); }
if (cont) { tracef("cont = "); coefficient_print(ctx, cont, trace_out); tracef("\n"); }
}
}
