1 files changed, 45 insertions, 0 deletions
diff --git a/bcc-bruce/misc/test/sievecp.t b/bcc-bruce/misc/test/sievecp.t
new file mode 100644
index 0000000..185b031
--- /dev/null
+++ b/bcc-bruce/misc/test/sievecp.t
@@ -0,0 +1,45 @@
+/* sieve using pointers */
+
+#define TRUE 1
+#define FALSE 0
+#define NITER 100
+#define SIZE 8191					/* last prime <= 2*this+3 */
+#define SQRSIZE 63					/* last divisor tested = 2*this+3 */
+
+char flags[SIZE+2*SQRSIZE+3];		/* avoid ptr+=prime overflowing */
+
+main()
+{
+	int i,count,iter;
+	register char *ptr;
+	char *endptr;
+	int prime;
+
+	for (iter=0;iter<NITER;iter++)
+	{
+		count=0;
+		ptr=flags;
+		endptr=flags+SIZE;
+		while (ptr<endptr)
+			*ptr++=TRUE;
+		for (i=0;i<SQRSIZE;i++)
+		{
+			if (flags[i])
+			{
+				prime=i+i+3;
+				ptr=flags+i+prime;		/* ptr<endptr since i<SQRSIZE */
+				while (ptr<endptr)
+				{
+					*ptr=FALSE;
+					ptr+=prime;			/* does not overflow since in flags */
+				}
+				count++;
+			}
+		}
+		ptr=flags+SQRSIZE;
+		while (ptr<endptr)
+			if (*ptr++)
+				count++;
+	}
+	printf( "%d primes\n", count );
+}