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/* See LICENSE file for copyright and license details. */
#include "internals"
#define ta libzahl_tmp_divmod_a
#define tb libzahl_tmp_divmod_b
#define td libzahl_tmp_divmod_d
#define te libzahl_tmp_divmod_e
void
zdivmod(z_t a, z_t b, z_t c, z_t d)
{
size_t c_bits, d_bits, shift;
int sign, cmpmag;
sign = zsignum(c) * zsignum(d);
if (!sign) {
if (zzero(c)) {
if (zzero(d)) {
errno = EDOM; /* Indeterminate form: 0 divided by 0 */
FAILURE_JUMP();
} else {
SET_SIGNUM(a, 0);
SET_SIGNUM(b, 0);
}
} else {
errno = EDOM; /* Undefined form: Division by 0 */
FAILURE_JUMP();
}
return;
} else if ((cmpmag = zcmpmag(c, d)) <= 0) {
if (cmpmag == 0) {
zseti(a, sign);
SET_SIGNUM(b, 0);
return;
} else if (sign < 0) {
zsub_unsigned(b, d, c);
} else if (b != c) {
zset(b, c);
}
SET_SIGNUM(b, 1);
SET_SIGNUM(a, 0);
return;
}
c_bits = zbits(c);
d_bits = zbits(d);
shift = c_bits - d_bits;
zlsh(td, d, shift);
SET_SIGNUM(td, 1);
if (zcmpmag(td, c) > 0) {
zrsh(td, td, 1);
shift -= 1;
}
zsetu(te, 1);
zlsh(te, te, shift);
SET_SIGNUM(ta, 0);
zabs(tb, c);
while (!zzero(te)) {
if (zcmpmag(td, tb) <= 0) {
zsub(tb, tb, td);
zor(ta, ta, te);
}
zrsh(te, te, 1);
zrsh(td, td, 1);
}
zset(a, ta);
zset(b, tb);
SET_SIGNUM(a, sign);
}
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