/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <bio.h> double big = 9.007199254740992e15; int pt[] ={	  2,  3,  5,  7, 11, 13, 17, 19, 23, 29,	 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,	 73, 79, 83, 89, 97,101,103,107,109,113,	127,131,137,139,149,151,157,163,167,173,	179,181,191,193,197,199,211,223,227,229,};double wheel[] ={	10, 2, 4, 2, 4, 6, 2, 6, 4, 2,	 4, 6, 6, 2, 6, 4, 2, 6, 4, 6,	 8, 4, 2, 4, 2, 4, 8, 6, 4, 6,	 2, 4, 6, 2, 6, 6, 4, 2, 4, 6,	 2, 6, 4, 2, 4, 2,10, 2,};uchar table[1000];uchar bittab[] ={	1, 2, 4, 8, 16, 32, 64, 128,}; enum {	ptsiz	= nelem(pt),	whsiz	= nelem(wheel),	tabsiz	= nelem(table),	tsiz8	= tabsiz*8,}; void	mark(double nn, long k); voidusage(void){	fprint(2, "usage: %s [start [finish]]\n", argv0);	exits("limits");} voidouch(void){	fprint(2, "limits exceeded\n");	exits("limits");} voidmain(int argc, char *argv[]){	int i;	double k, temp, v, limit, nn;	char *l;	Biobuf bin; 	ARGBEGIN{	default:		usage();		break;	}ARGEND; 	nn = 0;	limit = big;	switch (argc) {	case 0:		Binit(&bin, 0, OREAD);		while ((l = Brdline(&bin, '\n')) != nil) {			if (*l == '\n')				continue;			nn = atof(l);			if(nn < 0)				sysfatal("negative start");			break;		}		Bterm(&bin);		break;	case 2:		limit = atof(argv[1]);		if(limit < nn)			exits(0);		if(limit > big)			ouch();		/* fallthrough */	case 1:		nn = atof(argv[0]);		break;	default:		usage();		break;	} 	if(nn < 0 || nn > big)		ouch();	if(nn == 0)		nn = 1; 	if(nn < 230) {		for(i=0; i<ptsiz; i++) {			if(pt[i] < nn)				continue;			if(pt[i] > limit)				exits(0);			print("%d\n", pt[i]);//			if(limit >= big)//				exits(0);		}		nn = 230;	} 	modf(nn/2, &temp);	nn = 2*temp + 1;/* *	clear the sieve table. */	for(;;) {		for(i = 0; i < tabsiz; i++)			table[i] = 0;/* *	run the sieve. */		v = sqrt(nn+tsiz8);		mark(nn, 3);		mark(nn, 5);		mark(nn, 7);		for(i = 0, k = 11; k <= v; k += wheel[i]) {			mark(nn, k);			i++;			if(i >= whsiz)				i = 0;		}/* *	now get the primes from the table *	and print them. */		for(i = 0; i < tsiz8; i += 2) {			if(table[i>>3] & bittab[i&07])				continue;			temp = nn + i;			if(temp > limit)				exits(0);			print("%.0f\n", temp);//			if(limit >= big)//				exits(0);		}		nn += tsiz8;	}} voidmark(double nn, long k){	double t1;	long j; 	modf(nn/k, &t1);	j = k*t1 - nn;	if(j < 0)		j += k;	for(; j < tsiz8; j += k)		table[j>>3] |= bittab[j&07];}