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author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | 2022-04-14 01:12:18 +0000 |
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committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | 2022-04-14 01:12:18 +0000 |
commit | b776a5a69fd84adc49856063036e4199ca242afd (patch) | |
tree | 2ce94d7f0804ccb77d1fa9b2a1bca00eecdff1e2 /third_party/abseil-cpp/absl/strings/internal/charconv_bigint_test.cc | |
parent | 333ef124ffda132b5875022c64da196e383c8133 (diff) | |
parent | 43d8f56cdc20240b37c36bf417dd0d6999bce738 (diff) | |
download | webrtc-b776a5a69fd84adc49856063036e4199ca242afd.tar.gz |
Snap for 8451885 from 43d8f56cdc20240b37c36bf417dd0d6999bce738 to tm-d1-releaseandroid-13.0.0_r9android-13.0.0_r15android-13.0.0_r14android-13.0.0_r13android-13.0.0_r11android-13.0.0_r10android13-d1-s3-releaseandroid13-d1-s2-releaseandroid13-d1-s1-releaseandroid13-d1-release
Change-Id: Ie9306a92a47fa51147ae289d42a662ded50fe04f
Diffstat (limited to 'third_party/abseil-cpp/absl/strings/internal/charconv_bigint_test.cc')
-rw-r--r-- | third_party/abseil-cpp/absl/strings/internal/charconv_bigint_test.cc | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/third_party/abseil-cpp/absl/strings/internal/charconv_bigint_test.cc b/third_party/abseil-cpp/absl/strings/internal/charconv_bigint_test.cc index 363bcb03d9..a8b9945829 100644 --- a/third_party/abseil-cpp/absl/strings/internal/charconv_bigint_test.cc +++ b/third_party/abseil-cpp/absl/strings/internal/charconv_bigint_test.cc @@ -69,6 +69,61 @@ TEST(BigUnsigned, ShiftLeft) { // And we should have fully rotated all bits off by now: EXPECT_EQ(a, BigUnsigned<84>(0u)); } + { + // Bit shifting large and small numbers by large and small offsets. + // Intended to exercise bounds-checking corner on ShiftLeft() (directly + // and under asan). + + // 2**(32*84)-1 + const BigUnsigned<84> all_bits_one( + "1474444211396924248063325089479706787923460402125687709454567433186613" + "6228083464060749874845919674257665016359189106695900028098437021384227" + "3285029708032466536084583113729486015826557532750465299832071590813090" + "2011853039837649252477307070509704043541368002938784757296893793903797" + "8180292336310543540677175225040919704702800559606097685920595947397024" + "8303316808753252115729411497720357971050627997031988036134171378490368" + "6008000778741115399296162550786288457245180872759047016734959330367829" + "5235612397427686310674725251378116268607113017720538636924549612987647" + "5767411074510311386444547332882472126067840027882117834454260409440463" + "9345147252664893456053258463203120637089916304618696601333953616715125" + "2115882482473279040772264257431663818610405673876655957323083702713344" + "4201105427930770976052393421467136557055"); + const BigUnsigned<84> zero(0u); + const BigUnsigned<84> one(1u); + // in bounds shifts + for (int i = 1; i < 84*32; ++i) { + // shifting all_bits_one to the left should result in a smaller number, + // since the high bits rotate off and the low bits are replaced with + // zeroes. + BigUnsigned<84> big_shifted = all_bits_one; + big_shifted.ShiftLeft(i); + EXPECT_GT(all_bits_one, big_shifted); + // Shifting 1 to the left should instead result in a larger number. + BigUnsigned<84> small_shifted = one; + small_shifted.ShiftLeft(i); + EXPECT_LT(one, small_shifted); + } + // Shifting by zero or a negative number has no effect + for (int no_op_shift : {0, -1, -84 * 32, std::numeric_limits<int>::min()}) { + BigUnsigned<84> big_shifted = all_bits_one; + big_shifted.ShiftLeft(no_op_shift); + EXPECT_EQ(all_bits_one, big_shifted); + BigUnsigned<84> small_shifted = one; + big_shifted.ShiftLeft(no_op_shift); + EXPECT_EQ(one, small_shifted); + } + // Shifting by an amount greater than the number of bits should result in + // zero. + for (int out_of_bounds_shift : + {84 * 32, 84 * 32 + 1, std::numeric_limits<int>::max()}) { + BigUnsigned<84> big_shifted = all_bits_one; + big_shifted.ShiftLeft(out_of_bounds_shift); + EXPECT_EQ(zero, big_shifted); + BigUnsigned<84> small_shifted = one; + small_shifted.ShiftLeft(out_of_bounds_shift); + EXPECT_EQ(zero, small_shifted); + } + } } TEST(BigUnsigned, MultiplyByUint32) { |