1 files changed, 58 insertions, 0 deletions
diff --git a/libstdc++-v3/testsuite/performance/21_strings/hash.cc b/libstdc++-v3/testsuite/performance/21_strings/hash.cc
new file mode 100644
index 000000000..0c409c5da
--- /dev/null
+++ b/libstdc++-v3/testsuite/performance/21_strings/hash.cc
@@ -0,0 +1,58 @@
+#include <string>
+#include <vector>
+#include <unordered_set>
+#include <cstdlib>
+#include <random>
+#include <testsuite_performance.h>
+
+using namespace std;
+
+vector<string>
+random_strings(int n, int len)
+{
+  string s(len, '\0');
+  unordered_set<string> result_set;
+  random_device rd;
+  while (result_set.size() < n)
+    {
+      result_set.insert(s);
+      unsigned int tmp = rd();
+      tmp %= len * 256;
+      s[tmp / 256] = tmp % 256;
+    }
+  return vector<string>(result_set.begin(), result_set.end());
+}
+
+int
+main(int argc, char **argv)
+{
+  using namespace __gnu_test;
+  time_counter time;
+  resource_counter resource;
+
+  int string_size = 71;
+  int num_strings = 6000000;
+  if (argc > 1)
+    {
+      string_size = atoi(argv[1]);
+      if (argc > 2) 
+	num_strings = atoi(argv[2]);
+    }
+
+  // Construct random strings.
+  vector<string> v = random_strings(num_strings, string_size);
+
+  // Time hashing.
+  size_t tmp = 0;  // prevent compiler from optimizing away all the work
+  start_counters(time, resource);
+  for (int i = 0; i < num_strings; i++)
+    tmp += hash<string>()(v[i]);
+  stop_counters(time, resource);
+
+  if (tmp != 0 || argc < 9) // use tmp to prevent compiler optimization
+    report_performance(__FILE__, "", time, resource);
+
+  clear_counters(time, resource);
+
+  return 0;
+}