X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fmem%2Fbench%2Fspeed.c;fp=ccan%2Fmem%2Fbench%2Fspeed.c;h=18938214f5e9c14376cf3a2db6da35fa58b41996;hb=ca2551bcedb6ebd66814a2d4fdce7494b19d9b0d;hp=0000000000000000000000000000000000000000;hpb=299170fa67ff3cf664cbcd2c95c4a85d0d6e699d;p=ccan

diff --git a/ccan/mem/bench/speed.c b/ccan/mem/bench/speed.c
new file mode 100644
index 00000000..18938214
--- /dev/null
+++ b/ccan/mem/bench/speed.c
@@ -0,0 +1,49 @@
+/* Test speed of memiszero */
+#include <ccan/time/time.h>
+#include <ccan/mem/mem.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+
+#define MAX_TEST 65536
+
+int main(int argc, char *argv[])
+{
+	size_t n, i, max = argv[1] ? atol(argv[1]) : 100000000, runs;
+	char *arr;
+	size_t total = 0;
+
+	arr = calloc(1, max + MAX_TEST + 1);
+
+	runs = max;
+	/* First test even sizes case. */
+	for (n = 1; n <= MAX_TEST; n *= 2) {
+		struct timeabs start = time_now();
+		struct timerel each;
+
+		for (i = 0; i < runs; i++)
+			total += memeqzero(arr + i, n);
+		each = time_divide(time_between(time_now(), start), runs);
+		assert(each.ts.tv_sec == 0);
+		printf("%zu: %uns\n", n, (unsigned int)each.ts.tv_nsec);
+
+		/* Reduce runs over time, as bigger take longer. */
+		runs = runs * 2 / 3;
+	}
+
+	runs = max;
+	for (n = 1; n <= MAX_TEST; n *= 2) {
+		struct timeabs start = time_now();
+		struct timerel each;
+
+		for (i = 0; i < runs; i++)
+			total += memeqzero(arr + i, n+1);
+		each = time_divide(time_between(time_now(), start), runs);
+		assert(each.ts.tv_sec == 0);
+		printf("%zu: %uns\n", n+1, (unsigned int)each.ts.tv_nsec);
+		runs = runs * 2 / 3;
+	}
+
+	printf("total = %zu\n", total);
+	return 0;
+}