crypto/sha256: add benchmark.

[ccan] / ccan / crypto / sha256 / benchmarks / double-sha-bench.c

diff --git a/ccan/crypto/sha256/benchmarks/double-sha-bench.c b/ccan/crypto/sha256/benchmarks/double-sha-bench.c
new file mode 100644 (file)
index 0000000..93fd9d3
--- /dev/null
+++ b/ccan/crypto/sha256/benchmarks/double-sha-bench.c
@@ -0,0 +1,23 @@
+/* Bitcoin does a lot of SHA of SHA.  Benchmark that. */
+#include <ccan/crypto/sha256/sha256.h>
+#include <ccan/time/time.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+       struct timeabs start;
+       struct timerel diff;
+       size_t i, n;
+       struct sha256 h;
+
+       n = atoi(argv[1] ? argv[1] : "1000000");
+       sha256(&h, &n, sizeof(n));
+       start = time_now();
+       for (i = 0; i < n; i++)
+               sha256(&h, &h, sizeof(h));
+       diff = time_divide(time_between(time_now(), start), n);
+       printf("Hashing time for %02x%02x%02x%02x%02x%02x... is %llu nsec\n",
+              h.u.u8[0], h.u.u8[1], h.u.u8[2], h.u.u8[3], h.u.u8[4], h.u.u8[5],
+              (unsigned long long)time_to_nsec(diff));
+       return 0;
+}