mirror of
https://github.com/dart-lang/sdk
synced 2024-09-05 16:41:07 +00:00
[corelib] Test for overflow in int.modPow()
Bug: 37469 Change-Id: If7a6cc1063ddfdab1c5a0261a7b0c5d168c081b7 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/109316 Reviewed-by: Lasse R.H. Nielsen <lrn@google.com> Commit-Queue: Stephen Adams <sra@google.com>
This commit is contained in:
parent
6073489539
commit
f77093145a
47
tests/corelib_2/int_modpow_hard_test.dart
Normal file
47
tests/corelib_2/int_modpow_hard_test.dart
Normal file
|
@ -0,0 +1,47 @@
|
|||
// Copyright (c) 2019, 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.
|
||||
|
||||
// Extreme values from int_modulo_arith_test. Test cases that that have
|
||||
// intermediate values that overflow the precision of 'int'.
|
||||
|
||||
import "package:expect/expect.dart";
|
||||
|
||||
import "dart:math" show pow;
|
||||
|
||||
main() {
|
||||
test(x, e, m, expectedResult) {
|
||||
var result = x.modPow(e, m);
|
||||
Expect.equals(expectedResult, result, "$x.modPow($e, $m)");
|
||||
}
|
||||
|
||||
for (int mBase in [
|
||||
50000000,
|
||||
94906266, // Smallest integer with square over 2^53.
|
||||
100000000,
|
||||
1000000000,
|
||||
3037000500, // Smallest integer with square over 2^63.
|
||||
4000000000,
|
||||
0x7FFFFFFFFFFFF000 + 0xFFC
|
||||
]) {
|
||||
// On 'web' platforms skip values outside web number safe range.
|
||||
if (mBase == mBase + 1) continue;
|
||||
|
||||
for (int mAdjustment in [0, 1, 2, 3, -1]) {
|
||||
int m = mBase + mAdjustment;
|
||||
for (int e = 1; e < 100; e++) {
|
||||
// Test "M-k ^ N mod M == (-k) ^ N mod M" for some small values of k.
|
||||
test(m - 1, e, m, pow(-1, e) % m);
|
||||
if (e < 53) {
|
||||
test(m - 2, e, m, pow(-2, e) % m);
|
||||
}
|
||||
if (e < 33) {
|
||||
test(m - 3, e, m, pow(-3, e) % m);
|
||||
}
|
||||
if (e < 26) {
|
||||
test(m - 4, e, m, pow(-4, e) % m);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
Loading…
Reference in a new issue