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// Copyright 2017 The Abseil Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "absl/random/internal/fast_uniform_bits.h"
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#include <random>
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#include "gtest/gtest.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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namespace random_internal {
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namespace {
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template <typename IntType>
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class FastUniformBitsTypedTest : public ::testing::Test {};
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using IntTypes = ::testing::Types<uint8_t, uint16_t, uint32_t, uint64_t>;
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TYPED_TEST_SUITE(FastUniformBitsTypedTest, IntTypes);
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TYPED_TEST(FastUniformBitsTypedTest, BasicTest) {
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using Limits = std::numeric_limits<TypeParam>;
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using FastBits = FastUniformBits<TypeParam>;
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Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
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EXPECT_EQ(0, (FastBits::min)());
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EXPECT_EQ((Limits::max)(), (FastBits::max)());
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constexpr int kIters = 10000;
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std::random_device rd;
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std::mt19937 gen(rd());
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FastBits fast;
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for (int i = 0; i < kIters; i++) {
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const auto v = fast(gen);
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Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
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EXPECT_LE(v, (FastBits::max)());
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EXPECT_GE(v, (FastBits::min)());
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}
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}
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template <typename UIntType, UIntType Lo, UIntType Hi, UIntType Val = Lo>
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struct FakeUrbg {
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using result_type = UIntType;
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Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
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FakeUrbg() = default;
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explicit FakeUrbg(bool r) : reject(r) {}
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static constexpr result_type(max)() { return Hi; }
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static constexpr result_type(min)() { return Lo; }
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
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result_type operator()() {
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// when reject is set, return Hi half the time.
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return ((++calls % 2) == 1 && reject) ? Hi : Val;
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}
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|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
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bool reject = false;
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size_t calls = 0;
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};
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TEST(FastUniformBitsTest, IsPowerOfTwoOrZero) {
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EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{0}));
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EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{1}));
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EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{2}));
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EXPECT_FALSE(IsPowerOfTwoOrZero(uint8_t{3}));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{4}));
|
|
|
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EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{16}));
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EXPECT_FALSE(IsPowerOfTwoOrZero(uint8_t{17}));
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EXPECT_FALSE(IsPowerOfTwoOrZero((std::numeric_limits<uint8_t>::max)()));
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EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{0}));
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EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{1}));
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EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{2}));
|
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EXPECT_FALSE(IsPowerOfTwoOrZero(uint16_t{3}));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{4}));
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{16}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero(uint16_t{17}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero((std::numeric_limits<uint16_t>::max)()));
|
|
|
|
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint32_t{0}));
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint32_t{1}));
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint32_t{2}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero(uint32_t{3}));
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint32_t{32}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero(uint32_t{17}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero((std::numeric_limits<uint32_t>::max)()));
|
|
|
|
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{0}));
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{1}));
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{2}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero(uint64_t{3}));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{4}));
|
|
|
|
EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{64}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero(uint64_t{17}));
|
|
|
|
EXPECT_FALSE(IsPowerOfTwoOrZero((std::numeric_limits<uint64_t>::max)()));
|
|
|
|
}
|
|
|
|
|
|
|
|
TEST(FastUniformBitsTest, IntegerLog2) {
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0, IntegerLog2(uint16_t{0}));
|
|
|
|
EXPECT_EQ(0, IntegerLog2(uint16_t{1}));
|
|
|
|
EXPECT_EQ(1, IntegerLog2(uint16_t{2}));
|
|
|
|
EXPECT_EQ(1, IntegerLog2(uint16_t{3}));
|
|
|
|
EXPECT_EQ(2, IntegerLog2(uint16_t{4}));
|
|
|
|
EXPECT_EQ(2, IntegerLog2(uint16_t{5}));
|
|
|
|
EXPECT_EQ(2, IntegerLog2(uint16_t{7}));
|
|
|
|
EXPECT_EQ(3, IntegerLog2(uint16_t{8}));
|
|
|
|
EXPECT_EQ(63, IntegerLog2((std::numeric_limits<uint64_t>::max)()));
|
|
|
|
}
|
|
|
|
|
|
|
|
TEST(FastUniformBitsTest, RangeSize) {
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(2, (RangeSize<FakeUrbg<uint8_t, 0, 1>>()));
|
|
|
|
EXPECT_EQ(3, (RangeSize<FakeUrbg<uint8_t, 0, 2>>()));
|
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint8_t, 0, 3>>()));
|
|
|
|
// EXPECT_EQ(0, (RangeSize<FakeUrbg<uint8_t, 2, 2>>()));
|
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint8_t, 2, 5>>()));
|
|
|
|
EXPECT_EQ(5, (RangeSize<FakeUrbg<uint8_t, 2, 6>>()));
|
|
|
|
EXPECT_EQ(9, (RangeSize<FakeUrbg<uint8_t, 2, 10>>()));
|
|
|
|
EXPECT_EQ(
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
0, (RangeSize<
|
|
|
|
FakeUrbg<uint8_t, 0, (std::numeric_limits<uint8_t>::max)()>>()));
|
|
|
|
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint16_t, 0, 3>>()));
|
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint16_t, 2, 5>>()));
|
|
|
|
EXPECT_EQ(5, (RangeSize<FakeUrbg<uint16_t, 2, 6>>()));
|
|
|
|
EXPECT_EQ(18, (RangeSize<FakeUrbg<uint16_t, 1000, 1017>>()));
|
|
|
|
EXPECT_EQ(
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
0, (RangeSize<
|
|
|
|
FakeUrbg<uint16_t, 0, (std::numeric_limits<uint16_t>::max)()>>()));
|
|
|
|
|
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint32_t, 0, 3>>()));
|
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint32_t, 2, 5>>()));
|
|
|
|
EXPECT_EQ(5, (RangeSize<FakeUrbg<uint32_t, 2, 6>>()));
|
|
|
|
EXPECT_EQ(18, (RangeSize<FakeUrbg<uint32_t, 1000, 1017>>()));
|
|
|
|
EXPECT_EQ(0, (RangeSize<FakeUrbg<uint32_t, 0, 0xffffffff>>()));
|
|
|
|
EXPECT_EQ(0xffffffff, (RangeSize<FakeUrbg<uint32_t, 1, 0xffffffff>>()));
|
|
|
|
EXPECT_EQ(0xfffffffe, (RangeSize<FakeUrbg<uint32_t, 1, 0xfffffffe>>()));
|
|
|
|
EXPECT_EQ(0xfffffffd, (RangeSize<FakeUrbg<uint32_t, 2, 0xfffffffe>>()));
|
|
|
|
EXPECT_EQ(
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
0, (RangeSize<
|
|
|
|
FakeUrbg<uint32_t, 0, (std::numeric_limits<uint32_t>::max)()>>()));
|
|
|
|
|
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint64_t, 0, 3>>()));
|
|
|
|
EXPECT_EQ(4, (RangeSize<FakeUrbg<uint64_t, 2, 5>>()));
|
|
|
|
EXPECT_EQ(5, (RangeSize<FakeUrbg<uint64_t, 2, 6>>()));
|
|
|
|
EXPECT_EQ(18, (RangeSize<FakeUrbg<uint64_t, 1000, 1017>>()));
|
|
|
|
EXPECT_EQ(0x100000000, (RangeSize<FakeUrbg<uint64_t, 0, 0xffffffff>>()));
|
|
|
|
EXPECT_EQ(0xffffffff, (RangeSize<FakeUrbg<uint64_t, 1, 0xffffffff>>()));
|
|
|
|
EXPECT_EQ(0xfffffffe, (RangeSize<FakeUrbg<uint64_t, 1, 0xfffffffe>>()));
|
|
|
|
EXPECT_EQ(0xfffffffd, (RangeSize<FakeUrbg<uint64_t, 2, 0xfffffffe>>()));
|
|
|
|
EXPECT_EQ(0, (RangeSize<FakeUrbg<uint64_t, 0, 0xffffffffffffffff>>()));
|
|
|
|
EXPECT_EQ(0xffffffffffffffff,
|
|
|
|
(RangeSize<FakeUrbg<uint64_t, 1, 0xffffffffffffffff>>()));
|
|
|
|
EXPECT_EQ(0xfffffffffffffffe,
|
|
|
|
(RangeSize<FakeUrbg<uint64_t, 1, 0xfffffffffffffffe>>()));
|
|
|
|
EXPECT_EQ(0xfffffffffffffffd,
|
|
|
|
(RangeSize<FakeUrbg<uint64_t, 2, 0xfffffffffffffffe>>()));
|
|
|
|
EXPECT_EQ(
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
0, (RangeSize<
|
|
|
|
FakeUrbg<uint64_t, 0, (std::numeric_limits<uint64_t>::max)()>>()));
|
|
|
|
}
|
|
|
|
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
// The constants need to be choosen so that an infinite rejection loop doesn't
|
|
|
|
// happen...
|
|
|
|
using Urng1_5bit = FakeUrbg<uint8_t, 0, 2, 0>; // ~1.5 bits (range 3)
|
|
|
|
using Urng4bits = FakeUrbg<uint8_t, 1, 0x10, 2>;
|
|
|
|
using Urng22bits = FakeUrbg<uint32_t, 0, 0x3fffff, 0x301020>;
|
|
|
|
using Urng31bits = FakeUrbg<uint32_t, 1, 0xfffffffe, 0x60070f03>; // ~31.9 bits
|
|
|
|
using Urng32bits = FakeUrbg<uint32_t, 0, 0xffffffff, 0x74010f01>;
|
|
|
|
using Urng33bits =
|
|
|
|
FakeUrbg<uint64_t, 1, 0x1ffffffff, 0x013301033>; // ~32.9 bits
|
|
|
|
using Urng63bits = FakeUrbg<uint64_t, 1, 0xfffffffffffffffe,
|
|
|
|
0xfedcba9012345678>; // ~63.9 bits
|
|
|
|
using Urng64bits =
|
|
|
|
FakeUrbg<uint64_t, 0, 0xffffffffffffffff, 0x123456780fedcba9>;
|
|
|
|
|
|
|
|
TEST(FastUniformBitsTest, OutputsUpTo32Bits) {
|
|
|
|
// Tests that how values are composed; the single-bit deltas should be spread
|
|
|
|
// across each invocation.
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
Urng1_5bit urng1_5;
|
|
|
|
Urng4bits urng4;
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
Urng22bits urng22;
|
|
|
|
Urng31bits urng31;
|
|
|
|
Urng32bits urng32;
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
Urng33bits urng33;
|
|
|
|
Urng63bits urng63;
|
|
|
|
Urng64bits urng64;
|
|
|
|
|
|
|
|
// 8-bit types
|
|
|
|
{
|
|
|
|
FastUniformBits<uint8_t> fast8;
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x0, fast8(urng1_5));
|
|
|
|
EXPECT_EQ(0x11, fast8(urng4));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x20, fast8(urng22));
|
|
|
|
EXPECT_EQ(0x2, fast8(urng31));
|
|
|
|
EXPECT_EQ(0x1, fast8(urng32));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x32, fast8(urng33));
|
|
|
|
EXPECT_EQ(0x77, fast8(urng63));
|
|
|
|
EXPECT_EQ(0xa9, fast8(urng64));
|
|
|
|
}
|
|
|
|
|
|
|
|
// 16-bit types
|
|
|
|
{
|
|
|
|
FastUniformBits<uint16_t> fast16;
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x0, fast16(urng1_5));
|
|
|
|
EXPECT_EQ(0x1111, fast16(urng4));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x1020, fast16(urng22));
|
|
|
|
EXPECT_EQ(0x0f02, fast16(urng31));
|
|
|
|
EXPECT_EQ(0x0f01, fast16(urng32));
|
|
|
|
EXPECT_EQ(0x1032, fast16(urng33));
|
|
|
|
EXPECT_EQ(0x5677, fast16(urng63));
|
|
|
|
EXPECT_EQ(0xcba9, fast16(urng64));
|
|
|
|
}
|
|
|
|
|
|
|
|
// 32-bit types
|
|
|
|
{
|
|
|
|
FastUniformBits<uint32_t> fast32;
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x0, fast32(urng1_5));
|
|
|
|
EXPECT_EQ(0x11111111, fast32(urng4));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x08301020, fast32(urng22));
|
|
|
|
EXPECT_EQ(0x0f020f02, fast32(urng31));
|
|
|
|
EXPECT_EQ(0x74010f01, fast32(urng32));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x13301032, fast32(urng33));
|
|
|
|
EXPECT_EQ(0x12345677, fast32(urng63));
|
|
|
|
EXPECT_EQ(0x0fedcba9, fast32(urng64));
|
|
|
|
}
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
}
|
|
|
|
|
|
|
|
TEST(FastUniformBitsTest, Outputs64Bits) {
|
|
|
|
// Tests that how values are composed; the single-bit deltas should be spread
|
|
|
|
// across each invocation.
|
|
|
|
FastUniformBits<uint64_t> fast64;
|
|
|
|
|
|
|
|
{
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
FakeUrbg<uint8_t, 0, 1, 0> urng0;
|
|
|
|
FakeUrbg<uint8_t, 0, 1, 1> urng1;
|
|
|
|
Urng4bits urng4;
|
|
|
|
Urng22bits urng22;
|
|
|
|
Urng31bits urng31;
|
|
|
|
Urng32bits urng32;
|
|
|
|
Urng33bits urng33;
|
|
|
|
Urng63bits urng63;
|
|
|
|
Urng64bits urng64;
|
|
|
|
|
|
|
|
// somewhat degenerate cases only create a single bit.
|
|
|
|
EXPECT_EQ(0x0, fast64(urng0));
|
|
|
|
EXPECT_EQ(64, urng0.calls);
|
|
|
|
EXPECT_EQ(0xffffffffffffffff, fast64(urng1));
|
|
|
|
EXPECT_EQ(64, urng1.calls);
|
|
|
|
|
|
|
|
// less degenerate cases.
|
|
|
|
EXPECT_EQ(0x1111111111111111, fast64(urng4));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(16, urng4.calls);
|
|
|
|
EXPECT_EQ(0x01020c0408301020, fast64(urng22));
|
|
|
|
EXPECT_EQ(3, urng22.calls);
|
|
|
|
EXPECT_EQ(0x387811c3c0870f02, fast64(urng31));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(3, urng31.calls);
|
|
|
|
EXPECT_EQ(0x74010f0174010f01, fast64(urng32));
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(2, urng32.calls);
|
|
|
|
EXPECT_EQ(0x808194040cb01032, fast64(urng33));
|
|
|
|
EXPECT_EQ(3, urng33.calls);
|
|
|
|
EXPECT_EQ(0x1234567712345677, fast64(urng63));
|
|
|
|
EXPECT_EQ(2, urng63.calls);
|
|
|
|
EXPECT_EQ(0x123456780fedcba9, fast64(urng64));
|
|
|
|
EXPECT_EQ(1, urng64.calls);
|
|
|
|
}
|
|
|
|
|
|
|
|
// The 1.5 bit case is somewhat interesting in that the algorithm refinement
|
|
|
|
// causes one extra small sample. Comments here reference the names used in
|
|
|
|
// [rand.adapt.ibits] that correspond to this case.
|
|
|
|
{
|
|
|
|
Urng1_5bit urng1_5;
|
|
|
|
|
|
|
|
// w = 64
|
|
|
|
// R = 3
|
|
|
|
// m = 1
|
|
|
|
// n' = 64
|
|
|
|
// w0' = 1
|
|
|
|
// y0' = 2
|
|
|
|
// n = (1 <= 0) > 64 : 65 = 65
|
|
|
|
// n0 = 65 - (64%65) = 1
|
|
|
|
// n1 = 64
|
|
|
|
// w0 = 0
|
|
|
|
// y0 = 3
|
|
|
|
// w1 = 1
|
|
|
|
// y1 = 2
|
|
|
|
EXPECT_EQ(0x0, fast64(urng1_5));
|
|
|
|
EXPECT_EQ(65, urng1_5.calls);
|
|
|
|
}
|
|
|
|
|
|
|
|
// Validate rejections for non-power-of-2 cases.
|
|
|
|
{
|
|
|
|
Urng1_5bit urng1_5(true);
|
|
|
|
Urng31bits urng31(true);
|
|
|
|
Urng33bits urng33(true);
|
|
|
|
Urng63bits urng63(true);
|
|
|
|
|
|
|
|
// For 1.5 bits, there would be 1+2*64, except the first
|
|
|
|
// value was accepted and shifted off the end.
|
|
|
|
EXPECT_EQ(0, fast64(urng1_5));
|
|
|
|
EXPECT_EQ(128, urng1_5.calls);
|
|
|
|
EXPECT_EQ(0x387811c3c0870f02, fast64(urng31));
|
|
|
|
EXPECT_EQ(6, urng31.calls);
|
|
|
|
EXPECT_EQ(0x808194040cb01032, fast64(urng33));
|
|
|
|
EXPECT_EQ(6, urng33.calls);
|
|
|
|
EXPECT_EQ(0x1234567712345677, fast64(urng63));
|
|
|
|
EXPECT_EQ(4, urng63.calls);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
TEST(FastUniformBitsTest, URBG32bitRegression) {
|
|
|
|
// Validate with deterministic 32-bit std::minstd_rand
|
|
|
|
// to ensure that operator() performs as expected.
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
|
|
|
|
EXPECT_EQ(2147483646, RangeSize<std::minstd_rand>());
|
|
|
|
EXPECT_EQ(30, IntegerLog2(RangeSize<std::minstd_rand>()));
|
|
|
|
|
|
|
|
std::minstd_rand gen(1);
|
|
|
|
FastUniformBits<uint64_t> fast64;
|
|
|
|
|
Export of internal Abseil changes
--
4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>:
Import of CCTZ from GitHub.
PiperOrigin-RevId: 320398694
--
a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>:
Update CMakeLists.txt
Import of https://github.com/abseil/abseil-cpp/pull/737
PiperOrigin-RevId: 320391906
--
b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>:
Improves a comment about use of absl::Condition.
PiperOrigin-RevId: 320384329
--
c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>:
Improve FastUniformBits performance for std::minstd_rand.
The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive.
For example, minstd_rand has a range of
[1, 2147483646], which has a range of 2145386495, or about 30.999 bits.
Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1%
NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases.
PiperOrigin-RevId: 320285836
--
15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>:
Internal change.
PiperOrigin-RevId: 320220913
--
ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320181729
--
4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176084
--
6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>:
Internal change
PiperOrigin-RevId: 320176070
--
b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>:
Disabling using header module as well as building one for randen_hwaes_impl
PiperOrigin-RevId: 320024299
GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415
Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
4 years ago
|
|
|
EXPECT_EQ(0x05e47095f8791f45, fast64(gen));
|
|
|
|
EXPECT_EQ(0x028be17e3c07c122, fast64(gen));
|
|
|
|
EXPECT_EQ(0x55d2847c1626e8c2, fast64(gen));
|
|
|
|
}
|
|
|
|
|
|
|
|
} // namespace
|
|
|
|
} // namespace random_internal
|
|
|
|
ABSL_NAMESPACE_END
|
|
|
|
} // namespace absl
|