long sieve_next(sieve *sp)
{
long out;
int ix = 0;
long val;
if(sp->next > sp->nbits)
return -1;
out = S_VAL(sp, sp->next);
#ifdef DEBUG
fprintf(stderr, "Sieving %ld\n", out);
#endif
/* Sieve out all multiples of the current prime */
val = out;
while(ix < sp->nbits) {
val += out;
ix = S_BIT(sp, val);
if((val & 1) && ix < sp->nbits) { /* && S_ISSET(sp, ix)) { */
S_CLR(sp, ix);
#ifdef DEBUG
fprintf(stderr, "Crossing out %ld (bit %d)\n", val, ix);
#endif
}
}
/* Scan ahead to the next prime */
++sp->next;
while(sp->next < sp->nbits && !S_ISSET(sp, sp->next))
++sp->next;
return out;
}
int conf_read(const char *name)
{
FILE *in = NULL;
char line[1024];
char *p, *p2;
int lineno = 0;
struct symbol *sym;
struct property *prop;
struct expr *e;
int i;
if (name) {
in = fopen(name, "r");
} else {
const char **names = conf_confnames;
while ((name = *names++)) {
name = conf_expand_value(name);
in = fopen(name, "r");
if (in) {
printf("#\n"
"# using defaults found in %s\n"
"#\n", name);
break;
}
}
}
if (!in)
return 1;
for_all_symbols(i, sym) {
sym->flags |= SYMBOL_NEW | SYMBOL_CHANGED;
sym->flags &= ~SYMBOL_VALID;
switch (sym->type) {
case S_INT:
case S_HEX:
case S_STRING:
if (S_VAL(sym->def))
free(S_VAL(sym->def));
default:
S_VAL(sym->def) = NULL;
S_TRI(sym->def) = no;
;
}
}
int main(int argc, char *argv[])
{
sieve s;
long pr, *p;
int c, ix, cur = 0;
if(argc < 2) {
fprintf(stderr, "Usage: %s <width>\n", argv[0]);
return 1;
}
c = atoi(argv[1]);
if(c < 0) c = -c;
fprintf(stderr, "%s: sieving to %d positions\n", argv[0], c);
sieve_init(&s, 3, c);
c = 0;
while((pr = sieve_next(&s)) > 0) {
++c;
}
p = calloc(c, sizeof(long));
if(!p) {
fprintf(stderr, "%s: out of memory after first half\n", argv[0]);
sieve_clear(&s);
exit(1);
}
fprintf(stderr, "%s: half done ... \n", argv[0]);
for(ix = 0; ix < s.nbits; ix++) {
if(S_ISSET(&s, ix)) {
p[cur] = S_VAL(&s, ix);
printf("%ld\n", p[cur]);
++cur;
}
}
sieve_reset(&s, p[cur - 1]);
fprintf(stderr, "%s: crossing off %d found primes ... \n", argv[0], cur);
for(ix = 0; ix < cur; ix++) {
sieve_cross(&s, p[ix]);
if(!(ix % 1000))
fputc('.', stderr);
}
fputc('\n', stderr);
free(p);
fprintf(stderr, "%s: sieving again from %ld ... \n", argv[0], p[cur - 1]);
c = 0;
while((pr = sieve_next(&s)) > 0) {
++c;
}
fprintf(stderr, "%s: done!\n", argv[0]);
for(ix = 0; ix < s.nbits; ix++) {
if(S_ISSET(&s, ix)) {
printf("%ld\n", S_VAL(&s, ix));
}
}
sieve_clear(&s);
return 0;
}
