[js-perf-tests] Improve string benchmarks

Add inbounds benchmark for String.p.charCodeAt
and add in and out of bounds benchmarks for
String.p.codePointAt.

Bug: v8:7092, v8:7326, chromium:806758
Change-Id: I48065627bd79d8fb24e55b2f6dce590e7adbbd6e
Reviewed-on: https://chromium-review.googlesource.com/891858Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50942}

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

@@ -35,20 +35,31 @@ function StringIndexOfNonConstant() {
   return sum;
 }
 
-new BenchmarkSuite('StringCharCodeAtConstant', [3], [
-  new Benchmark('StringIndexOfConstant', true, false, 0,
-  StringCharCodeAtConstant),
+new BenchmarkSuite('StringCharCodeAtConstantWithOutOfBounds', [3], [
+  new Benchmark('StringCharCodeAtConstantWithOutOfBounds', true, false, 0,
+  StringCharCodeAtConstantWithOutOfBounds),
 ]);
 
-new BenchmarkSuite('StringCharCodeAtNonConstant', [3], [
-  new Benchmark('StringIndexOfNonConstant', true, false, 0,
-  StringCharCodeAtNonConstant),
+new BenchmarkSuite('StringCharCodeAtNonConstantWithOutOfBounds', [3], [
+  new Benchmark('StringCharCodeAtNonConstantWithOutOfBounds', true, false, 0,
+  StringCharCodeAtNonConstantWithOutOfBounds),
+]);
+
+new BenchmarkSuite('StringCharCodeAtConstantInbounds', [3], [
+  new Benchmark('StringCharCodeAtConstantInbounds', true, false, 0,
+  StringCharCodeAtConstantInbounds),
+]);
+
+new BenchmarkSuite('StringCharCodeAtNonConstantInbounds', [3], [
+  new Benchmark('StringCharCodeAtNonConstantInbounds', true, false, 0,
+  StringCharCodeAtNonConstantInbounds),
 ]);
 
 const string = "qweruiplkjhgfdsazxccvbnm";
 const indices = [1, 13, 32, 100, "xx"];
+const indicesInbounds = [1, 7, 13, 17, "xx"];
 
-function StringCharCodeAtConstant() {
+function StringCharCodeAtConstantWithOutOfBounds() {
   var sum = 0;
 
   for (var j = 0; j < indices.length - 1; ++j) {
@@ -58,7 +69,7 @@ function StringCharCodeAtConstant() {
   return sum;
 }
 
-function StringCharCodeAtNonConstant() {
+function StringCharCodeAtNonConstantWithOutOfBounds() {
   var sum = 0;
 
   for (var j = 0; j < indices.length - 1; ++j) {
@@ -67,3 +78,85 @@ function StringCharCodeAtNonConstant() {
 
   return sum;
 }
+
+function StringCharCodeAtConstantInbounds() {
+  var sum = 0;
+
+  for (var j = 0; j < indicesInbounds.length - 1; ++j) {
+    sum += string.charCodeAt(indicesInbounds[j] | 0);
+  }
+
+  return sum;
+}
+
+function StringCharCodeAtNonConstantInbounds() {
+  var sum = 0;
+
+  for (var j = 0; j < indicesInbounds.length - 1; ++j) {
+    sum += string.charCodeAt(indicesInbounds[j]);
+  }
+
+  return sum;
+}
+
+new BenchmarkSuite('StringCodePointAtConstantWithOutOfBounds', [3], [
+  new Benchmark('StringCodePointAtConstantWithOutOfBounds', true, false, 0,
+  StringCodePointAtConstantWithOutOfBounds),
+]);
+
+new BenchmarkSuite('StringCodePointAtNonConstantWithOutOfBounds', [3], [
+  new Benchmark('StringCodePointAtNonConstantWithOutOfBounds', true, false, 0,
+  StringCodePointAtNonConstantWithOutOfBounds),
+]);
+
+new BenchmarkSuite('StringCodePointAtConstantInbounds', [3], [
+  new Benchmark('StringCodePointAtConstantInbounds', true, false, 0,
+  StringCodePointAtConstantInbounds),
+]);
+
+new BenchmarkSuite('StringCodePointAtNonConstantInbounds', [3], [
+  new Benchmark('StringCodePointAtNonConstantInbounds', true, false, 0,
+  StringCodePointAtNonConstantInbounds),
+]);
+
+const unicode_string = "qweräϠ�𝌆krefdäϠ�𝌆ccäϠ�𝌆";
+
+function StringCodePointAtConstantWithOutOfBounds() {
+  var sum = 0;
+
+  for (var j = 0; j < indices.length - 1; ++j) {
+    sum += unicode_string.codePointAt(indices[j] | 0);
+  }
+
+  return sum;
+}
+
+function StringCodePointAtNonConstantWithOutOfBounds() {
+  var sum = 0;
+
+  for (var j = 0; j < indices.length - 1; ++j) {
+    sum += unicode_string.codePointAt(indices[j]);
+  }
+
+  return sum;
+}
+
+function StringCodePointAtConstantInbounds() {
+  var sum = 0;
+
+  for (var j = 0; j < indicesInbounds.length - 1; ++j) {
+    sum += unicode_string.codePointAt(indicesInbounds[j] | 0);
+  }
+
+  return sum;
+}
+
+function StringCodePointAtNonConstantInbounds() {
+  var sum = 0;
+
+  for (var j = 0; j < indicesInbounds.length - 1; ++j) {
+    sum += unicode_string.codePointAt(indicesInbounds[j]);
+  }
+
+  return sum;
+}