[Perf] Add ExpressionDepth test.

Adds a 'performance' test which tracks the number of expressions
which can be nested before the compiler runs out of stack space.
This isn't really a performance test, but is created as a js-perf-test
to enable regression tracking in the dashboards.

Change-Id: Iee0c00df53b38b083e2dde09676ac9b13e439461
Reviewed-on: https://chromium-review.googlesource.com/539419Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46019}

test/js-perf-test/ExpressionDepth/run.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.
+
+// Logical Expressions
+AddTest('Or-Value', '||', false);
+AddTest('Or-Test', '||', true);
+AddTest('And-Value', '&&', false);
+AddTest('And-Test', '&&', true);
+AddTest('Comma-Value', ',', false);
+AddTest('Comma-Test', ',', true);
+AddTest('Comma-Test', ',', true);
+
+// Compare Expressions
+AddTest('Equals-Value', '==', false);
+AddTest('Equals-Test', '==', true);
+AddTest('StrictEquals-Value', '===', false);
+AddTest('StrictEquals-Test', '===', true);
+AddTest('GreaterThan-Value', '>', false);
+AddTest('GreaterThan-Test', '>', true);
+
+// Binary Expressions
+AddTest('Add', '+');
+AddTest('Sub', '-');
+AddTest('BitwiseOr', '|');
+AddTestCustomPrologue('StringConcat', '+', '"string" +');
+
+function TestExpressionDepth(depth, expression, prologue, epilogue) {
+  var func = '(function f(a) {\n' + prologue;
+  for (var i = 0; i < depth; i++) {
+    func += 'a ' + expression;
+  }
+  func += 'a' + epilogue + '})();'
+  eval(func);
+}
+
+function RunTest(name, expression, prologue, epilogue) {
+  var depth;
+  try {
+    for (depth = 0; depth < 20000; depth += 100) {
+      TestExpressionDepth(depth, expression, prologue, epilogue);
+    }
+  } catch (e) {
+    if (!e instanceof RangeError) {
+      print(name +  '-ExpressionDepth(Score): ERROR');
+      return;
+    }
+  }
+  print(name + '-ExpressionDepth(Score): ' + depth);
+}
+
+function AddTest(name, expression, in_test) {
+  prologue = '';
+  epilogue = '';
+  if (in_test) {
+    prologue = 'if (';
+    epilogue = ') { return 1; }';
+  }
+  RunTest(name, expression, prologue, epilogue);
+}
+
+function AddTestCustomPrologue(name, expression, prologue) {
+  RunTest(name, expression, prologue, '');
+}

test/js-perf-test/JSTests.json

@@ -480,6 +480,31 @@
           ]
         }
       ]
+    },
+    {
+      "name": "ExpressionDepth",
+      "path": ["ExpressionDepth"],
+      "main": "run.js",
+      "flags": [ "--no-opt" ],
+      "results_regexp": "^%s\\-ExpressionDepth\\(Score\\): (.+)$",
+      "tests": [
+        {"name": "Or-Value"},
+        {"name": "Or-Test"},
+        {"name": "And-Value"},
+        {"name": "And-Test"},
+        {"name": "Comma-Value"},
+        {"name": "Comma-Test"},
+        {"name": "Equals-Value"},
+        {"name": "Equals-Test"},
+        {"name": "StrictEquals-Value"},
+        {"name": "StrictEquals-Test"},
+        {"name": "GreaterThan-Value"},
+        {"name": "GreaterThan-Test"},
+        {"name": "Add"},
+        {"name": "Sub"},
+        {"name": "StringConcat"},
+        {"name": "BitwiseOr"}
+      ]
     }
   ]
 }