void zTrial(fact_obj_t *fobj)
{
//trial divide n using primes below limit. optionally, print factors found.
//input expected in the gmp_n field of div_obj.
uint32 r,k=0;
uint32 limit = fobj->div_obj.limit;
int print = fobj->div_obj.print;
FILE *flog;
fp_digit q;
mpz_t tmp;
mpz_init(tmp);
flog = fopen(fobj->flogname,"a");
if (flog == NULL)
{
printf("fopen error: %s\n", strerror(errno));
printf("could not open %s for writing\n",fobj->flogname);
return;
}
if (P_MAX < limit)
{
free(PRIMES);
PRIMES = soe_wrapper(spSOEprimes, szSOEp, 0, limit, 0, &NUM_P);
P_MIN = PRIMES[0];
P_MAX = PRIMES[NUM_P-1];
}
while ((mpz_cmp_ui(fobj->div_obj.gmp_n, 1) > 0) &&
(PRIMES[k] < limit) &&
(k < (uint32)NUM_P))
{
q = (fp_digit)PRIMES[k];
r = mpz_tdiv_ui(fobj->div_obj.gmp_n, q);
if (r != 0)
k++;
else
{
mpz_tdiv_q_ui(fobj->div_obj.gmp_n, fobj->div_obj.gmp_n, q);
mpz_set_64(tmp, q);
add_to_factor_list(fobj, tmp);
#if BITS_PER_DIGIT == 64
logprint(flog,"div: found prime factor = %" PRIu64 "\n",q);
#else
logprint(flog,"div: found prime factor = %u\n",q);
#endif
if (print && (VFLAG > 0))
#if BITS_PER_DIGIT == 64
printf("div: found prime factor = %" PRIu64 "\n",q);
#else
printf("div: found prime factor = %u\n",q);
#endif
}
}
fclose(flog);
mpz_clear(tmp);
}
void trial_divide_Q_siqs(uint32 report_num, uint8 parity,
uint32 poly_id, uint32 bnum,
static_conf_t *sconf, dynamic_conf_t *dconf)
{
//we have flagged this sieve offset as likely to produce a relation
//nothing left to do now but check and see.
uint64 q64, f64;
int j,it;
uint32 prime;
int smooth_num;
uint32 *fb_offsets;
uint32 polya_factors[20];
sieve_fb *fb;
uint32 offset, block_loc;
fb_offsets = &dconf->fb_offsets[report_num][0];
smooth_num = dconf->smooth_num[report_num];
block_loc = dconf->reports[report_num];
#ifdef QS_TIMING
gettimeofday(&qs_timing_start, NULL);
#endif
offset = (bnum << sconf->qs_blockbits) + block_loc;
if (parity)
fb = dconf->fb_sieve_n;
else
fb = dconf->fb_sieve_p;
#ifdef USE_YAFU_TDIV
z32_to_mpz(&dconf->Qvals32[report_num], dconf->Qvals[report_num]);
#endif
//check for additional factors of the a-poly factors
//make a separate list then merge it with fb_offsets
it=0; //max 20 factors allocated for - should be overkill
for (j = 0; (j < dconf->curr_poly->s) && (it < 20); j++)
{
//fbptr = fb + dconf->curr_poly->qlisort[j];
//prime = fbptr->prime;
prime = fb[dconf->curr_poly->qlisort[j]].prime;
while ((mpz_tdiv_ui(dconf->Qvals[report_num],prime) == 0) && (it < 20))
{
mpz_tdiv_q_ui(dconf->Qvals[report_num], dconf->Qvals[report_num], prime);
polya_factors[it++] = dconf->curr_poly->qlisort[j];
}
}
//check if it completely factored by looking at the unfactored portion in tmp
//if ((mpz_size(dconf->Qvals[report_num]) == 1) &&
//(mpz_get_64(dconf->Qvals[report_num]) < (uint64)sconf->large_prime_max))
if ((mpz_size(dconf->Qvals[report_num]) == 1) &&
(mpz_cmp_ui(dconf->Qvals[report_num], sconf->large_prime_max) < 0))
{
uint32 large_prime[2];
large_prime[0] = (uint32)mpz_get_ui(dconf->Qvals[report_num]); //Q->val[0];
large_prime[1] = 1;
//add this one
if (sconf->is_tiny)
{
// we need to encode both the a_poly and b_poly index
// in poly_id
poly_id |= (sconf->total_poly_a << 16);
buffer_relation(offset,large_prime,smooth_num+1,
fb_offsets,poly_id,parity,dconf,polya_factors,it);
}
else
buffer_relation(offset,large_prime,smooth_num+1,
fb_offsets,poly_id,parity,dconf,polya_factors,it);
#ifdef QS_TIMING
gettimeofday (&qs_timing_stop, NULL);
qs_timing_diff = my_difftime (&qs_timing_start, &qs_timing_stop);
TF_STG6 += ((double)qs_timing_diff->secs + (double)qs_timing_diff->usecs / 1000000);
free(qs_timing_diff);
#endif
return;
}
if (sconf->use_dlp == 0)
return;
//quick check if Q is way too big for DLP (more than 64 bits)
if (mpz_sizeinbase(dconf->Qvals[report_num], 2) >= 64)
return;
q64 = mpz_get_64(dconf->Qvals[report_num]);
if ((q64 > sconf->max_fb2) && (q64 < sconf->large_prime_max2))
{
//quick prime check: compute 2^(residue-1) mod residue.
uint64 res;
//printf("%llu\n",q64);
#if BITS_PER_DIGIT == 32
mpz_set_64(dconf->gmptmp1, q64);
mpz_set_64(dconf->gmptmp2, 2);
mpz_set_64(dconf->gmptmp3, q64-1);
mpz_powm(dconf->gmptmp1, dconf->gmptmp2, dconf->gmptmp3, dconf->gmptmp1);
res = mpz_get_64(dconf->gmptmp1);
#else
spModExp(2, q64 - 1, q64, &res);
#endif
//if equal to 1, assume it is prime. this may be wrong sometimes, but we don't care.
//more important to quickly weed out probable primes than to spend more time to be
//more sure.
if (res == 1)
{
#ifdef QS_TIMING
gettimeofday (&qs_timing_stop, NULL);
qs_timing_diff = my_difftime (&qs_timing_start, &qs_timing_stop);
TF_STG6 += ((double)qs_timing_diff->secs + (double)qs_timing_diff->usecs / 1000000);
free(qs_timing_diff);
#endif
dconf->dlp_prp++;
return;
}
//try to find a double large prime
#ifdef HAVE_CUDA
{
uint32 large_prime[2] = {1,1};
// remember the residue and the relation it is associated with
dconf->buf_id[dconf->num_squfof_cand] = dconf->buffered_rels;
dconf->squfof_candidates[dconf->num_squfof_cand++] = q64;
// buffer the relation
buffer_relation(offset,large_prime,smooth_num+1,
fb_offsets,poly_id,parity,dconf,polya_factors,it);
}
#else
dconf->attempted_squfof++;
mpz_set_64(dconf->gmptmp1, q64);
f64 = sp_shanks_loop(dconf->gmptmp1, sconf->obj);
if (f64 > 1 && f64 != q64)
{
uint32 large_prime[2];
large_prime[0] = (uint32)f64;
large_prime[1] = (uint32)(q64 / f64);
if (large_prime[0] < sconf->large_prime_max
&& large_prime[1] < sconf->large_prime_max)
{
//add this one
dconf->dlp_useful++;
buffer_relation(offset,large_prime,smooth_num+1,
fb_offsets,poly_id,parity,dconf,polya_factors,it);
}
}
else
{
dconf->failed_squfof++;
//printf("squfof failure: %" PRIu64 "\n", q64);
}
#endif
}
else
dconf->dlp_outside_range++;
#ifdef QS_TIMING
gettimeofday (&qs_timing_stop, NULL);
qs_timing_diff = my_difftime (&qs_timing_start, &qs_timing_stop);
TF_STG6 += ((double)qs_timing_diff->secs + (double)qs_timing_diff->usecs / 1000000);
free(qs_timing_diff);
#endif
return;
}