| // Copyright (c) 2013, 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. |
| // Testing int.bitLength, int.toUnsigned and int.toSigned. |
| |
| library bit_twiddling_test; |
| |
| import "package:expect/expect.dart"; |
| |
| testBitLength() { |
| check(int i, width) { |
| Expect.equals(width, i.bitLength, '$i.bitLength == $width'); |
| // (~i) written as (-i-1) to avoid issues with limited range of dart2js ops. |
| Expect.equals(width, (-i - 1).bitLength, '(~$i).bitLength == $width'); |
| } |
| |
| check(0, 0); |
| check(1, 1); |
| check(2, 2); |
| check(3, 2); |
| check(4, 3); |
| check(5, 3); |
| check(6, 3); |
| check(7, 3); |
| check(8, 4); |
| check(127, 7); |
| check(128, 8); |
| check(129, 8); |
| check(2147483646, 31); |
| check(2147483647, 31); |
| check(2147483648, 32); |
| check(2147483649, 32); |
| check(4294967295, 32); |
| check(4294967296, 33); |
| check(0xffffffffff, 40); |
| check(0xfffffffffff, 44); |
| check(0xffffffffffff, 48); |
| check(0x1000000000000, 49); |
| check(0x1000000000001, 49); |
| check(0x1ffffffffffff, 49); |
| check(0x2000000000000, 50); |
| check(0x2000000000001, 50); |
| |
| check(0xffffffffffffff, 56); // //# int64: ok |
| check(0x7fffffffffffffff, 63); // //# int64: continued |
| check(0xffffffffffffffff, 0); // //# int64: continued |
| } |
| |
| testToUnsigned() { |
| checkU(src, width, expected) { |
| Expect.equals(expected, src.toUnsigned(width)); |
| } |
| |
| checkU(1, 8, 1); |
| checkU(0xff, 8, 0xff); |
| checkU(0xffff, 8, 0xff); |
| checkU(-1, 8, 0xff); |
| checkU(0xffffffff, 32, 0xffffffff); |
| |
| checkU(0x7fffffff, 30, 0x3fffffff); |
| checkU(0x7fffffff, 31, 0x7fffffff); |
| checkU(0x7fffffff, 32, 0x7fffffff); |
| checkU(0x80000000, 30, 0); |
| checkU(0x80000000, 31, 0); |
| checkU(0x80000000, 32, 0x80000000); |
| checkU(0xffffffff, 30, 0x3fffffff); |
| checkU(0xffffffff, 31, 0x7fffffff); |
| checkU(0xffffffff, 32, 0xffffffff); |
| checkU(0x100000000, 30, 0); |
| checkU(0x100000000, 31, 0); |
| checkU(0x100000000, 32, 0); |
| checkU(0x1ffffffff, 30, 0x3fffffff); |
| checkU(0x1ffffffff, 31, 0x7fffffff); |
| checkU(0x1ffffffff, 32, 0xffffffff); |
| |
| checkU(-1, 0, 0); |
| checkU(0, 0, 0); |
| checkU(1, 0, 0); |
| checkU(2, 0, 0); |
| checkU(3, 0, 0); |
| |
| checkU(-1, 1, 1); |
| checkU(0, 1, 0); |
| checkU(1, 1, 1); |
| checkU(2, 1, 0); |
| checkU(3, 1, 1); |
| checkU(4, 1, 0); |
| |
| checkU(-1, 2, 3); |
| checkU(0, 2, 0); |
| checkU(1, 2, 1); |
| checkU(2, 2, 2); |
| checkU(3, 2, 3); |
| checkU(4, 2, 0); |
| |
| checkU(-1, 3, 7); |
| checkU(0, 3, 0); |
| checkU(1, 3, 1); |
| checkU(2, 3, 2); |
| checkU(3, 3, 3); |
| checkU(4, 3, 4); |
| |
| checkU(0x0100000000000001, 2, 1); // //# int64: continued |
| checkU(0x0200000000000001, 60, 0x200000000000001); // //# int64: continued |
| checkU(0x0200000000000001, 59, 0x200000000000001); // //# int64: continued |
| checkU(0x0200000000000001, 58, 0x200000000000001); // //# int64: continued |
| checkU(0x0200000000000001, 57, 1); // //# int64: continued |
| |
| checkU(0x8100000000000001, 2, 1); // //# int64: continued |
| checkU(0x8200000000000001, 60, 0x200000000000001); // //# int64: continued |
| checkU(0x8200000000000001, 59, 0x200000000000001); // //# int64: continued |
| checkU(0x8200000000000001, 58, 0x200000000000001); // //# int64: continued |
| checkU(0x8200000000000001, 57, 1); // //# int64: continued |
| } |
| |
| testToSigned() { |
| checkS(src, width, expected) { |
| Expect.equals( |
| expected, src.toSigned(width), '$src.toSigned($width) == $expected'); |
| } |
| |
| checkS(1, 8, 1); |
| checkS(0xff, 8, -1); |
| checkS(0xffff, 8, -1); |
| checkS(-1, 8, -1); |
| checkS(128, 8, -128); |
| checkS(0xffffffff, 32, -1); |
| |
| checkS(0x7fffffff, 30, -1); |
| checkS(0x7fffffff, 31, -1); |
| checkS(0x7fffffff, 32, 0x7fffffff); |
| checkS(0x80000000, 30, 0); |
| checkS(0x80000000, 31, 0); |
| checkS(0x80000000, 32, -2147483648); |
| checkS(0xffffffff, 30, -1); |
| checkS(0xffffffff, 31, -1); |
| checkS(0xffffffff, 32, -1); |
| |
| checkS(0x100000000, 30, 0); |
| checkS(0x100000000, 31, 0); |
| checkS(0x100000000, 32, 0); |
| checkS(0x1ffffffff, 30, -1); |
| checkS(0x1ffffffff, 31, -1); |
| checkS(0x1ffffffff, 32, -1); |
| |
| checkS(-1, 1, -1); |
| checkS(0, 1, 0); |
| checkS(1, 1, -1); // The only bit is the sign bit. |
| checkS(2, 1, 0); |
| checkS(3, 1, -1); |
| checkS(4, 1, 0); |
| |
| checkS(-1, 2, -1); |
| checkS(0, 2, 0); |
| checkS(1, 2, 1); |
| checkS(2, 2, -2); |
| checkS(3, 2, -1); |
| checkS(4, 2, 0); |
| |
| checkS(-1, 3, -1); |
| checkS(0, 3, 0); |
| checkS(1, 3, 1); |
| checkS(2, 3, 2); |
| checkS(3, 3, 3); |
| checkS(4, 3, -4); |
| |
| checkS(0x0100000000000001, 2, 1); // //# int64: continued |
| checkS(0x0200000000000001, 60, 0x200000000000001); // //# int64: continued |
| checkS(0x0200000000000001, 59, 0x200000000000001); // //# int64: continued |
| checkS(0x0200000000000001, 58, -0x200000000000000 + 1); // //# int64: continued |
| checkS(0x0200000000000001, 57, 1); // //# int64: continued |
| |
| checkS(0x8100000000000001, 2, 1); // //# int64: continued |
| checkS(0x8200000000000001, 60, 0x200000000000001); // //# int64: continued |
| checkS(0x8200000000000001, 59, 0x200000000000001); // //# int64: continued |
| checkS(0x8200000000000001, 58, -0x200000000000000 + 1); // //# int64: continued |
| checkS(0x8200000000000001, 57, 1); // //# int64: continued |
| } |
| |
| main() { |
| testBitLength(); |
| testToUnsigned(); |
| testToSigned(); |
| } |