Function bf_const_log2

third-party/quickjs/src/quickjs/libbf.c:4209–4213

}

int bf_const_log2(bf_t *T, limb_t prec, bf_flags_t flags)
{
    bf_context_t *s = T->ctx;
    return bf_const_get(T, prec, flags, &s->log2_cache, bf_const_log2_internal, 0);
}

/* return rounded pi * (1 - 2 * sign) */
static int bf_const_pi_signed(bf_t *T, int sign, limb_t prec, bf_flags_t flags)