Add trivial towlower/towupper benchmarks.

Currently 11ns for both ascii and unicode in 64-bit, 15ns for 32-bit.

Test: ran benchmarks
Change-Id: Ie810b324c855b52b66a96889a194bc5b5b55653f

benchmarks/Android.bp

@@ -40,6 +40,7 @@ cc_defaults {
         "string_benchmark.cpp",
         "time_benchmark.cpp",
         "unistd_benchmark.cpp",
+        "wctype_benchmark.cpp",
     ],
     shared_libs: ["liblog"],
     static_libs: [

benchmarks/wctype_benchmark.cpp

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <wctype.h>
+
+#include <benchmark/benchmark.h>
+#include "util.h"
+
+static void BM_wctype_towlower_ascii_y(benchmark::State& state) {
+  for (auto _ : state) {
+    towlower('X');
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towlower_ascii_y);
+
+static void BM_wctype_towlower_ascii_n(benchmark::State& state) {
+  for (auto _ : state) {
+    towlower('x');
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towlower_ascii_n);
+
+static void BM_wctype_towlower_unicode_y(benchmark::State& state) {
+  for (auto _ : state) {
+    towlower(0x0391);
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towlower_unicode_y);
+
+static void BM_wctype_towlower_unicode_n(benchmark::State& state) {
+  for (auto _ : state) {
+    towlower(0x03b1);
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towlower_unicode_n);
+
+static void BM_wctype_towupper_ascii_y(benchmark::State& state) {
+  for (auto _ : state) {
+    towupper('x');
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towupper_ascii_y);
+
+static void BM_wctype_towupper_ascii_n(benchmark::State& state) {
+  for (auto _ : state) {
+    towupper('X');
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towupper_ascii_n);
+
+static void BM_wctype_towupper_unicode_y(benchmark::State& state) {
+  for (auto _ : state) {
+    towupper(0x03b1);
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towupper_unicode_y);
+
+static void BM_wctype_towupper_unicode_n(benchmark::State& state) {
+  for (auto _ : state) {
+    towupper(0x0391);
+  }
+}
+BIONIC_BENCHMARK(BM_wctype_towupper_unicode_n);