tests/compiler/dart2js/tdiv_test.dart

// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

library tdiv_test;

import 'dart:async';
import 'package:expect/expect.dart';
import 'package:async_helper/async_helper.dart';
import 'compiler_helper.dart';

const String TEST1 = r"""
foo(param) {
  var a = param ? 0xFFFFFFFF : 1;
  return a ~/ 2;
  // Above can be compiled to division followed by truncate.
  // present: ' / 2 | 0'
  // absent: 'tdiv'
}
""";

const String TEST2 = r"""
foo(param) {
  var a = param ? 0xFFFFFFFF : 1;
  return a ~/ 3;
  // Above can be compiled to division followed by truncate.
  // present: ' / 3 | 0'
  // absent: 'tdiv'
}
""";

const String TEST3 = r"""
foo(param) {
  var a = param ? 0xFFFFFFFF : -1;
  return a ~/ 2;
  // Potentially negative inputs go via fast helper.
  // present: '_tdivFast'
  // absent: '/'
}
""";

const String TEST4 = r"""
foo(param1, param2) {
  var a = param1 ? 0xFFFFFFFF : 0;
  return a ~/ param2;
  // Unknown divisor goes via full implementation.
  // present: '$tdiv'
  // absent: '/'
}
""";

const String TEST5 = r"""
foo(param1, param2) {
  var a = param1 ? 0xFFFFFFFF : 0;
  var b = param2 ? 3 : 4;
  return a ~/ param2;
  // We could optimize this with range analysis, but type inference summarizes
  // '3 or 4' to uint31, which is not >= 2.
  // present: '$tdiv'
  // absent: '/'
}
""";

main() {
  RegExp directivePattern = new RegExp(
      //      \1                    \2        \3
      r'''// *(present|absent): (?:"([^"]*)"|'([^'']*)')''',
      multiLine: true);

  Future check(String test) {
    return compile(test, entry: 'foo', check: (String generated) {
      for (Match match in directivePattern.allMatches(test)) {
        String directive = match.group(1);
        String pattern = match.groups([2, 3]).where((s) => s != null).single;
        if (directive == 'present') {
          Expect.isTrue(generated.contains(pattern),
              "Cannot find '$pattern' in:\n$generated");
        } else {
          assert(directive == 'absent');
          Expect.isFalse(generated.contains(pattern),
              "Must not find '$pattern' in:\n$generated");
        }
      }
    });
  }

  asyncTest(() => Future.wait([
    check(TEST1),
    check(TEST2),
    check(TEST3),
    check(TEST4),
    check(TEST5),
  ]));
}