[turbofan] Add benchmarks for String.indexOf

Bug: v8:7127, v8:6270
Change-Id: Ic35a9b7a5145115736934b0c7de6ace26e9c0e51
Reviewed-on: https://chromium-review.googlesource.com/832966
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50191}

test/js-perf-test/JSTests.json

@@ -180,13 +180,15 @@
       "name": "Strings",
       "path": ["Strings"],
       "main": "run.js",
-      "resources": ["harmony-string.js"],
+      "resources": ["harmony-string.js", "string-indexof.js"],
       "results_regexp": "^%s\\-Strings\\(Score\\): (.+)$",
       "run_count": 1,
       "timeout": 240,
       "timeout_arm": 420,
       "tests": [
-        {"name": "StringFunctions"}
+        {"name": "StringFunctions"},
+        {"name": "StringIndexOfConstant"},
+        {"name": "StringIndexOfNonConstant"}
       ]
     },
     {

test/js-perf-test/Strings/run.js

@@ -5,6 +5,7 @@
 
 load('../base.js');
 load('harmony-string.js');
+load('string-indexof.js');
 
 
 var success = true;

test/js-perf-test/Strings/string-indexof.js

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+new BenchmarkSuite('StringIndexOfConstant', [1000], [
+  new Benchmark('StringIndexOfConstant', true, false, 0,
+  StringIndexOfConstant),
+]);
+
+new BenchmarkSuite('StringIndexOfNonConstant', [1000], [
+  new Benchmark('StringIndexOfNonConstant', true, false, 0,
+  StringIndexOfNonConstant),
+]);
+
+const N = 10 ** 6;
+const subject = "aaaaaaaaaaaaaaaab";
+const searches = ['a', 'b', 'c'];
+
+function StringIndexOfConstant() {
+  var sum = 0;
+
+  for (var j = 0; j < searches.length; ++j) {
+    sum += subject.indexOf("" + searches[j]);
+  }
+
+  return sum;
+}
+
+function StringIndexOfNonConstant() {
+  var sum = 0;
+
+  for (var j = 0; j < searches.length; ++j) {
+    sum += subject.indexOf(searches[j]);
+  }
+
+  return sum;
+}