dart-sdk/tests/corelib/int_modpow_hard_test.dart
Josh Soref ef42a0b110 Spelling pkg analyzer lib
Closes https://github.com/dart-lang/sdk/pull/50860

GitOrigin-RevId: b27066c37f93c8c6d1123d6ebd6a4c0afcf59844
Change-Id: I15fa4aea1dad45daf168e34d1c4450320ec9b40a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/277742
Commit-Queue: Alexander Thomas <athom@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Alexander Thomas <athom@google.com>
2023-01-25 14:08:27 +00:00

47 lines
1.4 KiB
Dart

// 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 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);
}
}
}
}
}