Add benchmarks for strcpy and strcmp.

Test: Ran benchmarks and verified that runtimes were sensible.
Change-Id: I609e3261503a015bfd4982767fef3ce56141aebc
diff --git a/benchmarks/string_benchmark.cpp b/benchmarks/string_benchmark.cpp
index e6c6570..86a7c35 100644
--- a/benchmarks/string_benchmark.cpp
+++ b/benchmarks/string_benchmark.cpp
@@ -173,3 +173,33 @@
   state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
 }
 BENCHMARK(BM_string_strcat_half_copy_half_seek)->AT_COMMON_SIZES;
+
+static void BM_string_strcpy(benchmark::State& state) {
+  const size_t nbytes = state.range(0);
+  std::vector<char> src(nbytes, 'x');
+  std::vector<char> dst(nbytes);
+  src[nbytes - 1] = '\0';
+
+  while (state.KeepRunning()) {
+    strcpy(dst.data(), src.data());
+  }
+
+  state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
+}
+BENCHMARK(BM_string_strcpy)->AT_COMMON_SIZES;
+
+static void BM_string_strcmp(benchmark::State& state) {
+  const size_t nbytes = state.range(0);
+  std::vector<char> s1(nbytes, 'x');
+  std::vector<char> s2(nbytes, 'x');
+  s1[nbytes - 1] = '\0';
+  s2[nbytes - 1] = '\0';
+
+  volatile int c __attribute__((unused));
+  while (state.KeepRunning()) {
+    c = strcmp(s1.data(), s2.data());
+  }
+
+  state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
+}
+BENCHMARK(BM_string_strcmp)->AT_COMMON_SIZES;