diff --git a/src/string/bench.c b/src/string/bench.c
new file mode 100644
index 0000000..fcfc1e9
--- /dev/null
+++ b/src/string/bench.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "test.h"
+
+#define LEN 200000
+
+static int bstrstr(int N, const char *needle) {
+	size_t l = strlen(needle);
+	size_t cnt = 10000;
+	int i;
+	int cs = 0;
+	char *haystack = malloc(l * cnt + 1);
+
+	for (i=0; i<cnt-1; i++) {
+		memcpy(haystack + l*i, needle, l);
+		haystack[l*i+l-1] ^= 1;
+	}
+	memcpy(haystack + l*i, needle, l+1);
+	for (i=0; i<N; i++) {
+		haystack[0]^=1;
+		cs += (int)strstr(haystack, needle);
+	}
+	free(haystack);
+	return cs;
+}
+
+void bench_string_strstr1(int N) {
+	bstrstr(N, "abcdefghijklmnopqrstuvwxyz");
+}
+void bench_string_strstr2(int N) {
+	bstrstr(N, "azbycxdwevfugthsirjqkplomn");
+}
+void bench_string_strstr3(int N) {
+	bstrstr(N, "aaaaaaaaaaaaaacccccccccccc");
+}
+void bench_string_strstr4(int N) {
+	bstrstr(N, "aaaaaaaaaaaaaaaaaaaaaaaaac");
+}
+void bench_string_strstr5(int N) {
+	bstrstr(N, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac");
+}
+
+void bench_string_memset(int N) {
+	char *buf = malloc(LEN);
+	int i;
+
+	for (i=0; i<N; i++)
+		memset(buf+i, i, LEN-i);
+	free(buf);
+}
+
+void bench_string_strchr(int N) {
+	char *buf = malloc(LEN);
+	int i;
+	int cs = 0;
+
+	memset(buf, 'a', LEN);
+	buf[LEN-1] = 0;
+	buf[LEN-2] = 'b';
+	reset_timer();
+	for (i=0; i<N; i++) {
+		buf[i] = '0'+i%8;
+		cs ^= (int)strchr(buf, 'b');
+	}
+	buf[0] = cs;
+	free(buf);
+}
+
+void bench_string_strlen(int N) {
+	char *buf = malloc(LEN);
+	int i;
+	int cs = 0;
+
+	memset(buf, 'a', LEN-1);
+	buf[LEN-1] = 0;
+	reset_timer();
+	for (i=0; i<N; i++) {
+		buf[i] = '0'+i%8;
+		cs ^= strlen(buf);
+	}
+	buf[0] = cs;
+	free(buf);
+}