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

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 0000000..f4b9cd5
--- /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