summaryrefslogtreecommitdiff
path: root/absl/random/internal/fast_uniform_bits_test.cc
diff options
context:
space:
mode:
authorGravatar Abseil Team <absl-team@google.com>2019-06-21 13:11:42 -0700
committerGravatar Gennadiy Rozental <rogeeff@google.com>2019-06-21 16:18:10 -0400
commite9324d926a9189e222741fce6e676f0944661a72 (patch)
treea08568a709940c376454da34c9d8aac021378e5f /absl/random/internal/fast_uniform_bits_test.cc
parent43ef2148c0936ebf7cb4be6b19927a9d9d145b8f (diff)
Export of internal Abseil changes.
-- 7a6ff16a85beb730c172d5d25cf1b5e1be885c56 by Laramie Leavitt <lar@google.com>: Internal change. PiperOrigin-RevId: 254454546 -- ff8f9bafaefc26d451f576ea4a06d150aed63f6f by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254451562 -- deefc5b651b479ce36f0b4ef203e119c0c8936f2 by CJ Johnson <johnsoncj@google.com>: Account for subtracting unsigned values from the size of InlinedVector PiperOrigin-RevId: 254450625 -- 3c677316a27bcadc17e41957c809ca472d5fef14 by Andy Soffer <asoffer@google.com>: Add C++17's std::make_from_tuple to absl/utility/utility.h PiperOrigin-RevId: 254411573 -- 4ee3536a918830eeec402a28fc31a62c7c90b940 by CJ Johnson <johnsoncj@google.com>: Adds benchmark for the rest of the InlinedVector public API PiperOrigin-RevId: 254408378 -- e5a21a00700ee83498ff1efbf649169756463ee4 by CJ Johnson <johnsoncj@google.com>: Updates the definition of InlinedVector::shrink_to_fit() to be exception safe and adds exception safety tests for it. PiperOrigin-RevId: 254401387 -- 2ea82e72b86d82d78b4e4712a63a55981b53c64b by Laramie Leavitt <lar@google.com>: Use absl::InsecureBitGen in place of std::mt19937 in tests absl/random/...distribution_test.cc PiperOrigin-RevId: 254289444 -- fa099e02c413a7ffda732415e8105cad26a90337 by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254286334 -- ce34b7f36933b30cfa35b9c9a5697a792b5666e4 by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254273059 -- 6f9c473da7c2090c2e85a37c5f00622e8a912a89 by Jorg Brown <jorg@google.com>: Change absl::container_internal::CompressedTuple to instantiate its internal Storage class with the name of the type it's holding, rather than the name of the Tuple. This is not an externally-visible change, other than less compiler memory is used and less debug information is generated. PiperOrigin-RevId: 254269285 -- 8bd3c186bf2fc0c55d8a2dd6f28a5327502c9fba by Andy Soffer <asoffer@google.com>: Adding short-hand IntervalClosed for IntervalClosedClosed and IntervalOpen for IntervalOpenOpen. PiperOrigin-RevId: 254252419 -- ea957f99b6a04fccd42aa05605605f3b44b1ecfd by Abseil Team <absl-team@google.com>: Do not directly use __SIZEOF_INT128__. In order to avoid linker errors when building with clang-cl (__fixunsdfti, __udivti3 and __fixunssfti are undefined), this CL uses ABSL_HAVE_INTRINSIC_INT128 which is not defined for clang-cl. PiperOrigin-RevId: 254250739 -- 89ab385cd26b34d64130bce856253aaba96d2345 by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254242321 -- cffc793d93eca6d6bdf7de733847b6ab4a255ae9 by CJ Johnson <johnsoncj@google.com>: Adds benchmark for InlinedVector::reserve(size_type) PiperOrigin-RevId: 254199226 -- c90c7a9fa3c8f0c9d5114036979548b055ea2f2a by Gennadiy Rozental <rogeeff@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 254072387 -- c4c388beae016c9570ab54ffa1d52660e4a85b7b by Laramie Leavitt <lar@google.com>: Internal cleanup. PiperOrigin-RevId: 254062381 -- d3c992e221cc74e5372d0c8fa410170b6a43c062 by Tom Manshreck <shreck@google.com>: Update distributions.h to Abseil standards PiperOrigin-RevId: 254054946 -- d15ad0035c34ef11b14fadc5a4a2d3ec415f5518 by CJ Johnson <johnsoncj@google.com>: Removes functions with only one caller from the implementation details of InlinedVector by manually inlining the definitions PiperOrigin-RevId: 254005427 -- 2f37e807efc3a8ef1f4b539bdd379917d4151520 by Andy Soffer <asoffer@google.com>: Initial release of Abseil Random PiperOrigin-RevId: 253999861 -- 24ed1694b6430791d781ed533a8f8ccf6cac5856 by CJ Johnson <johnsoncj@google.com>: Updates the definition of InlinedVector::assign(...)/InlinedVector::operator=(...) to new, exception-safe implementations with exception safety tests to boot PiperOrigin-RevId: 253993691 -- 5613d95f5a7e34a535cfaeadce801441e990843e by CJ Johnson <johnsoncj@google.com>: Adds benchmarks for InlinedVector::shrink_to_fit() PiperOrigin-RevId: 253989647 -- 2a96ddfdac40bbb8cb6a7f1aeab90917067c6e63 by Abseil Team <absl-team@google.com>: Initial release of Abseil Random PiperOrigin-RevId: 253927497 -- bf1aff8fc9ffa921ad74643e9525ecf25b0d8dc1 by Andy Soffer <asoffer@google.com>: Initial release of Abseil Random PiperOrigin-RevId: 253920512 -- bfc03f4a3dcda3cf3a4b84bdb84cda24e3394f41 by Laramie Leavitt <lar@google.com>: Internal change. PiperOrigin-RevId: 253886486 -- 05036cfcc078ca7c5f581a00dfb0daed568cbb69 by Eric Fiselier <ericwf@google.com>: Don't include `winsock2.h` because it drags in `windows.h` and friends, and they define awful macros like OPAQUE, ERROR, and more. This has the potential to break abseil users. Instead we only forward declare `timeval` and require Windows users include `winsock2.h` themselves. This is both inconsistent and poor QoI, but so including 'windows.h' is bad too. PiperOrigin-RevId: 253852615 GitOrigin-RevId: 7a6ff16a85beb730c172d5d25cf1b5e1be885c56 Change-Id: Icd6aff87da26f29ec8915da856f051129987cef6
Diffstat (limited to 'absl/random/internal/fast_uniform_bits_test.cc')
-rw-r--r--absl/random/internal/fast_uniform_bits_test.cc290
1 files changed, 290 insertions, 0 deletions
diff --git a/absl/random/internal/fast_uniform_bits_test.cc b/absl/random/internal/fast_uniform_bits_test.cc
new file mode 100644
index 00000000..f4b9cd5f
--- /dev/null
+++ b/absl/random/internal/fast_uniform_bits_test.cc
@@ -0,0 +1,290 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/random/internal/fast_uniform_bits.h"
+
+#include <random>
+
+#include "gtest/gtest.h"
+
+namespace {
+
+template <typename IntType>
+class FastUniformBitsTypedTest : public ::testing::Test {};
+
+using IntTypes = ::testing::Types<uint8_t, uint16_t, uint32_t, uint64_t>;
+
+TYPED_TEST_SUITE(FastUniformBitsTypedTest, IntTypes);
+
+TYPED_TEST(FastUniformBitsTypedTest, BasicTest) {
+ using Limits = std::numeric_limits<TypeParam>;
+ using FastBits = absl::random_internal::FastUniformBits<TypeParam>;
+
+ EXPECT_EQ(0, FastBits::min());
+ EXPECT_EQ(Limits::max(), FastBits::max());
+
+ constexpr int kIters = 10000;
+ std::random_device rd;
+ std::mt19937 gen(rd());
+ FastBits fast;
+ for (int i = 0; i < kIters; i++) {
+ const auto v = fast(gen);
+ EXPECT_LE(v, FastBits::max());
+ EXPECT_GE(v, FastBits::min());
+ }
+}
+
+TEST(FastUniformBitsTest, TypeBoundaries32) {
+ // Tests that FastUniformBits can adapt to 32-bit boundaries.
+ absl::random_internal::FastUniformBits<uint32_t, 1> a;
+ absl::random_internal::FastUniformBits<uint32_t, 31> b;
+ absl::random_internal::FastUniformBits<uint32_t, 32> c;
+
+ {
+ std::mt19937 gen; // 32-bit
+ a(gen);
+ b(gen);
+ c(gen);
+ }
+
+ {
+ std::mt19937_64 gen; // 64-bit
+ a(gen);
+ b(gen);
+ c(gen);
+ }
+}
+
+TEST(FastUniformBitsTest, TypeBoundaries64) {
+ // Tests that FastUniformBits can adapt to 64-bit boundaries.
+ absl::random_internal::FastUniformBits<uint64_t, 1> a;
+ absl::random_internal::FastUniformBits<uint64_t, 31> b;
+ absl::random_internal::FastUniformBits<uint64_t, 32> c;
+ absl::random_internal::FastUniformBits<uint64_t, 33> d;
+ absl::random_internal::FastUniformBits<uint64_t, 63> e;
+ absl::random_internal::FastUniformBits<uint64_t, 64> f;
+
+ {
+ std::mt19937 gen; // 32-bit
+ a(gen);
+ b(gen);
+ c(gen);
+ d(gen);
+ e(gen);
+ f(gen);
+ }
+
+ {
+ std::mt19937_64 gen; // 64-bit
+ a(gen);
+ b(gen);
+ c(gen);
+ d(gen);
+ e(gen);
+ f(gen);
+ }
+}
+
+class UrngOddbits {
+ public:
+ using result_type = uint8_t;
+ static constexpr result_type min() { return 1; }
+ static constexpr result_type max() { return 0xfe; }
+ result_type operator()() { return 2; }
+};
+
+class Urng4bits {
+ public:
+ using result_type = uint8_t;
+ static constexpr result_type min() { return 1; }
+ static constexpr result_type max() { return 0xf + 1; }
+ result_type operator()() { return 2; }
+};
+
+class Urng32bits {
+ public:
+ using result_type = uint32_t;
+ static constexpr result_type min() { return 0; }
+ static constexpr result_type max() { return 0xffffffff; }
+ result_type operator()() { return 1; }
+};
+
+// Compile-time test to validate the helper classes used by FastUniformBits
+TEST(FastUniformBitsTest, FastUniformBitsDetails) {
+ using absl::random_internal::FastUniformBitsLoopingConstants;
+ using absl::random_internal::FastUniformBitsURBGConstants;
+
+ // 4-bit URBG
+ {
+ using constants = FastUniformBitsURBGConstants<Urng4bits>;
+ static_assert(constants::kPowerOfTwo == true,
+ "constants::kPowerOfTwo == false");
+ static_assert(constants::kRange == 16, "constants::kRange == false");
+ static_assert(constants::kRangeBits == 4, "constants::kRangeBits == false");
+ static_assert(constants::kRangeMask == 0x0f,
+ "constants::kRangeMask == false");
+ }
+ {
+ using looping = FastUniformBitsLoopingConstants<uint32_t, 31, Urng4bits>;
+ // To get 31 bits from a 4-bit generator, issue 8 calls and extract 4 bits
+ // per call on all except the first.
+ static_assert(looping::kN0 == 1, "looping::kN0");
+ static_assert(looping::kW0 == 3, "looping::kW0");
+ static_assert(looping::kM0 == 0x7, "looping::kM0");
+ // (The second set of calls, kN1, will not do anything.)
+ static_assert(looping::kN1 == 8, "looping::kN1");
+ static_assert(looping::kW1 == 4, "looping::kW1");
+ static_assert(looping::kM1 == 0xf, "looping::kM1");
+ }
+
+ // ~7-bit URBG
+ {
+ using constants = FastUniformBitsURBGConstants<UrngOddbits>;
+ static_assert(constants::kPowerOfTwo == false,
+ "constants::kPowerOfTwo == false");
+ static_assert(constants::kRange == 0xfe, "constants::kRange == 0xfe");
+ static_assert(constants::kRangeBits == 7, "constants::kRangeBits == 7");
+ static_assert(constants::kRangeMask == 0x7f,
+ "constants::kRangeMask == 0x7f");
+ }
+ {
+ using looping = FastUniformBitsLoopingConstants<uint64_t, 60, UrngOddbits>;
+ // To get 60 bits from a 7-bit generator, issue 10 calls and extract 6 bits
+ // per call, discarding the excess entropy.
+ static_assert(looping::kN0 == 10, "looping::kN0");
+ static_assert(looping::kW0 == 6, "looping::kW0");
+ static_assert(looping::kM0 == 0x3f, "looping::kM0");
+ // (The second set of calls, kN1, will not do anything.)
+ static_assert(looping::kN1 == 10, "looping::kN1");
+ static_assert(looping::kW1 == 7, "looping::kW1");
+ static_assert(looping::kM1 == 0x7f, "looping::kM1");
+ }
+ {
+ using looping = FastUniformBitsLoopingConstants<uint64_t, 63, UrngOddbits>;
+ // To get 63 bits from a 7-bit generator, issue 10 calls--the same as we
+ // would issue for 60 bits--however this time we use two groups. The first
+ // group (kN0) will issue 7 calls, extracting 6 bits per call.
+ static_assert(looping::kN0 == 7, "looping::kN0");
+ static_assert(looping::kW0 == 6, "looping::kW0");
+ static_assert(looping::kM0 == 0x3f, "looping::kM0");
+ // The second group (kN1) will issue 3 calls, extracting 7 bits per call.
+ static_assert(looping::kN1 == 10, "looping::kN1");
+ static_assert(looping::kW1 == 7, "looping::kW1");
+ static_assert(looping::kM1 == 0x7f, "looping::kM1");
+ }
+}
+
+TEST(FastUniformBitsTest, Urng4_VariousOutputs) {
+ // Tests that how values are composed; the single-bit deltas should be spread
+ // across each invocation.
+ Urng4bits urng4;
+ Urng32bits urng32;
+
+ // 8-bit types
+ {
+ absl::random_internal::FastUniformBits<uint8_t, 1> fast1;
+ EXPECT_EQ(0x1, fast1(urng4));
+ EXPECT_EQ(0x1, fast1(urng32));
+ }
+ {
+ absl::random_internal::FastUniformBits<uint8_t, 2> fast2;
+ EXPECT_EQ(0x1, fast2(urng4));
+ EXPECT_EQ(0x1, fast2(urng32));
+ }
+
+ {
+ absl::random_internal::FastUniformBits<uint8_t, 4> fast4;
+ EXPECT_EQ(0x1, fast4(urng4));
+ EXPECT_EQ(0x1, fast4(urng32));
+ }
+ {
+ absl::random_internal::FastUniformBits<uint8_t, 6> fast6;
+ EXPECT_EQ(0x9, fast6(urng4)); // b001001 (2x3)
+ EXPECT_EQ(0x1, fast6(urng32));
+ }
+ {
+ absl::random_internal::FastUniformBits<uint8_t, 6> fast7;
+ EXPECT_EQ(0x9, fast7(urng4)); // b00001001 (1x4 + 1x3)
+ EXPECT_EQ(0x1, fast7(urng32));
+ }
+
+ {
+ absl::random_internal::FastUniformBits<uint8_t> fast8;
+ EXPECT_EQ(0x11, fast8(urng4));
+ EXPECT_EQ(0x1, fast8(urng32));
+ }
+
+ // 16-bit types
+ {
+ absl::random_internal::FastUniformBits<uint16_t, 10> fast10;
+ EXPECT_EQ(0x91, fast10(urng4)); // b 0010010001 (2x3 + 1x4)
+ EXPECT_EQ(0x1, fast10(urng32));
+ }
+ {
+ absl::random_internal::FastUniformBits<uint16_t, 11> fast11;
+ EXPECT_EQ(0x111, fast11(urng4));
+ EXPECT_EQ(0x1, fast11(urng32));
+ }
+ {
+ absl::random_internal::FastUniformBits<uint16_t, 12> fast12;
+ EXPECT_EQ(0x111, fast12(urng4));
+ EXPECT_EQ(0x1, fast12(urng32));
+ }
+
+ {
+ absl::random_internal::FastUniformBits<uint16_t> fast16;
+ EXPECT_EQ(0x1111, fast16(urng4));
+ EXPECT_EQ(0x1, fast16(urng32));
+ }
+
+ // 32-bit types
+ {
+ absl::random_internal::FastUniformBits<uint32_t, 21> fast21;
+ EXPECT_EQ(0x49111, fast21(urng4)); // b 001001001 000100010001 (3x3 + 3x4)
+ EXPECT_EQ(0x1, fast21(urng32));
+ }
+ {
+ absl::random_internal::FastUniformBits<uint32_t, 24> fast24;
+ EXPECT_EQ(0x111111, fast24(urng4));
+ EXPECT_EQ(0x1, fast24(urng32));
+ }
+
+ {
+ absl::random_internal::FastUniformBits<uint32_t> fast32;
+ EXPECT_EQ(0x11111111, fast32(urng4));
+ EXPECT_EQ(0x1, fast32(urng32));
+ }
+
+ // 64-bit types
+ {
+ absl::random_internal::FastUniformBits<uint64_t, 5> fast5;
+ EXPECT_EQ(0x9, fast5(urng4));
+ EXPECT_EQ(0x1, fast5(urng32));
+ }
+
+ {
+ absl::random_internal::FastUniformBits<uint64_t, 48> fast48;
+ EXPECT_EQ(0x111111111111, fast48(urng4));
+ // computes in 2 steps, should be 24 << 24
+ EXPECT_EQ(0x000001000001, fast48(urng32));
+ }
+
+ {
+ absl::random_internal::FastUniformBits<uint64_t> fast64;
+ EXPECT_EQ(0x1111111111111111, fast64(urng4));
+ EXPECT_EQ(0x0000000100000001, fast64(urng32));
+ }
+}
+
+} // namespace