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-rw-r--r--CMake/AbseilDll.cmake1
-rw-r--r--absl/container/btree_benchmark.cc34
-rw-r--r--absl/numeric/BUILD.bazel12
-rw-r--r--absl/numeric/CMakeLists.txt12
-rw-r--r--absl/numeric/internal/representation.h55
-rw-r--r--absl/random/BUILD.bazel4
-rw-r--r--absl/random/CMakeLists.txt4
-rw-r--r--absl/random/beta_distribution_test.cc40
-rw-r--r--absl/random/exponential_distribution_test.cc28
-rw-r--r--absl/random/gaussian_distribution_test.cc35
-rw-r--r--absl/random/uniform_real_distribution_test.cc12
-rw-r--r--absl/strings/BUILD.bazel1
-rw-r--r--absl/strings/CMakeLists.txt1
-rw-r--r--absl/strings/internal/str_format/float_conversion.cc12
14 files changed, 138 insertions, 113 deletions
diff --git a/CMake/AbseilDll.cmake b/CMake/AbseilDll.cmake
index 47707dfd..39f85f2f 100644
--- a/CMake/AbseilDll.cmake
+++ b/CMake/AbseilDll.cmake
@@ -131,6 +131,7 @@ set(ABSL_INTERNAL_DLL_FILES
"numeric/int128.cc"
"numeric/int128.h"
"numeric/internal/bits.h"
+ "numeric/internal/representation.h"
"random/bernoulli_distribution.h"
"random/beta_distribution.h"
"random/bit_gen_ref.h"
diff --git a/absl/container/btree_benchmark.cc b/absl/container/btree_benchmark.cc
index 46798676..41f13f52 100644
--- a/absl/container/btree_benchmark.cc
+++ b/absl/container/btree_benchmark.cc
@@ -101,39 +101,6 @@ void BM_InsertSorted(benchmark::State& state) {
BM_InsertImpl<T>(state, true);
}
-// container::insert sometimes returns a pair<iterator, bool> and sometimes
-// returns an iterator (for multi- containers).
-template <typename Iter>
-Iter GetIterFromInsert(const std::pair<Iter, bool>& pair) {
- return pair.first;
-}
-template <typename Iter>
-Iter GetIterFromInsert(const Iter iter) {
- return iter;
-}
-
-// Benchmark insertion of values into a container at the end.
-template <typename T>
-void BM_InsertEnd(benchmark::State& state) {
- using V = typename remove_pair_const<typename T::value_type>::type;
- typename KeyOfValue<typename T::key_type, V>::type key_of_value;
-
- T container;
- const int kSize = 10000;
- for (int i = 0; i < kSize; ++i) {
- container.insert(Generator<V>(kSize)(i));
- }
- V v = Generator<V>(kSize)(kSize - 1);
- typename T::key_type k = key_of_value(v);
-
- auto it = container.find(k);
- while (state.KeepRunning()) {
- // Repeatedly removing then adding v.
- container.erase(it);
- it = GetIterFromInsert(container.insert(v));
- }
-}
-
// Benchmark inserting the first few elements in a container. In b-tree, this is
// when the root node grows.
template <typename T>
@@ -513,7 +480,6 @@ BTREE_TYPES(Time);
#define MY_BENCHMARK3(type) \
MY_BENCHMARK4(type, Insert); \
MY_BENCHMARK4(type, InsertSorted); \
- MY_BENCHMARK4(type, InsertEnd); \
MY_BENCHMARK4(type, InsertSmall); \
MY_BENCHMARK4(type, Lookup); \
MY_BENCHMARK4(type, FullLookup); \
diff --git a/absl/numeric/BUILD.bazel b/absl/numeric/BUILD.bazel
index 5d7b1857..ea587bfa 100644
--- a/absl/numeric/BUILD.bazel
+++ b/absl/numeric/BUILD.bazel
@@ -101,3 +101,15 @@ cc_test(
"@com_github_google_benchmark//:benchmark_main",
],
)
+
+cc_library(
+ name = "representation",
+ hdrs = [
+ "internal/representation.h",
+ ],
+ copts = ABSL_DEFAULT_COPTS,
+ linkopts = ABSL_DEFAULT_LINKOPTS,
+ deps = [
+ "//absl/base:config",
+ ],
+)
diff --git a/absl/numeric/CMakeLists.txt b/absl/numeric/CMakeLists.txt
index be94352a..781987dc 100644
--- a/absl/numeric/CMakeLists.txt
+++ b/absl/numeric/CMakeLists.txt
@@ -86,3 +86,15 @@ absl_cc_library(
absl::int128
PUBLIC
)
+
+absl_cc_library(
+ NAME
+ numeric_representation
+ HDRS
+ "internal/representation.h"
+ COPTS
+ ${ABSL_DEFAULT_COPTS}
+ DEPS
+ absl::config
+ PUBLIC
+)
diff --git a/absl/numeric/internal/representation.h b/absl/numeric/internal/representation.h
new file mode 100644
index 00000000..82d332fd
--- /dev/null
+++ b/absl/numeric/internal/representation.h
@@ -0,0 +1,55 @@
+// Copyright 2021 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.
+
+#ifndef ABSL_NUMERIC_INTERNAL_REPRESENTATION_H_
+#define ABSL_NUMERIC_INTERNAL_REPRESENTATION_H_
+
+#include <limits>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace numeric_internal {
+
+// Returns true iff long double is represented as a pair of doubles added
+// together.
+inline constexpr bool IsDoubleDouble() {
+ // A double-double value always has exactly twice the precision of a double
+ // value--one double carries the high digits and one double carries the low
+ // digits. This property is not shared with any other common floating-point
+ // representation, so this test won't trigger false positives. For reference,
+ // this table gives the number of bits of precision of each common
+ // floating-point representation:
+ //
+ // type precision
+ // IEEE single 24 b
+ // IEEE double 53
+ // x86 long double 64
+ // double-double 106
+ // IEEE quadruple 113
+ //
+ // Note in particular that a quadruple-precision float has greater precision
+ // than a double-double float despite taking up the same amount of memory; the
+ // quad has more of its bits allocated to the mantissa than the double-double
+ // has.
+ return std::numeric_limits<long double>::digits ==
+ 2 * std::numeric_limits<double>::digits;
+}
+
+} // namespace numeric_internal
+ABSL_NAMESPACE_END
+} // namespace absl
+
+#endif // ABSL_NUMERIC_INTERNAL_REPRESENTATION_H_
diff --git a/absl/random/BUILD.bazel b/absl/random/BUILD.bazel
index d97b2c4e..66ffcbc7 100644
--- a/absl/random/BUILD.bazel
+++ b/absl/random/BUILD.bazel
@@ -188,6 +188,7 @@ cc_test(
":distributions",
":random",
"//absl/base:raw_logging_internal",
+ "//absl/numeric:representation",
"//absl/random/internal:distribution_test_util",
"//absl/random/internal:pcg_engine",
"//absl/random/internal:sequence_urbg",
@@ -308,6 +309,7 @@ cc_test(
":random",
"//absl/base:core_headers",
"//absl/base:raw_logging_internal",
+ "//absl/numeric:representation",
"//absl/random/internal:distribution_test_util",
"//absl/random/internal:pcg_engine",
"//absl/random/internal:sequence_urbg",
@@ -331,6 +333,7 @@ cc_test(
":random",
"//absl/base:core_headers",
"//absl/base:raw_logging_internal",
+ "//absl/numeric:representation",
"//absl/random/internal:distribution_test_util",
"//absl/random/internal:sequence_urbg",
"//absl/strings",
@@ -377,6 +380,7 @@ cc_test(
":distributions",
":random",
"//absl/base:raw_logging_internal",
+ "//absl/numeric:representation",
"//absl/random/internal:distribution_test_util",
"//absl/random/internal:pcg_engine",
"//absl/random/internal:sequence_urbg",
diff --git a/absl/random/CMakeLists.txt b/absl/random/CMakeLists.txt
index 13093d6d..3009a034 100644
--- a/absl/random/CMakeLists.txt
+++ b/absl/random/CMakeLists.txt
@@ -259,6 +259,7 @@ absl_cc_test(
LINKOPTS
${ABSL_DEFAULT_LINKOPTS}
DEPS
+ absl::numeric_representation
absl::random_distributions
absl::random_random
absl::random_internal_distribution_test_util
@@ -381,6 +382,7 @@ absl_cc_test(
${ABSL_DEFAULT_LINKOPTS}
DEPS
absl::core_headers
+ absl::numeric_representation
absl::random_distributions
absl::random_internal_distribution_test_util
absl::random_internal_pcg_engine
@@ -404,6 +406,7 @@ absl_cc_test(
${ABSL_DEFAULT_LINKOPTS}
DEPS
absl::core_headers
+ absl::numeric_representation
absl::random_distributions
absl::random_internal_distribution_test_util
absl::random_internal_sequence_urbg
@@ -446,6 +449,7 @@ absl_cc_test(
LINKOPTS
${ABSL_DEFAULT_LINKOPTS}
DEPS
+ absl::numeric_representation
absl::random_distributions
absl::random_internal_distribution_test_util
absl::random_internal_pcg_engine
diff --git a/absl/random/beta_distribution_test.cc b/absl/random/beta_distribution_test.cc
index 277e4dc6..44cdfdd0 100644
--- a/absl/random/beta_distribution_test.cc
+++ b/absl/random/beta_distribution_test.cc
@@ -21,12 +21,14 @@
#include <random>
#include <sstream>
#include <string>
+#include <type_traits>
#include <unordered_map>
#include <vector>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/internal/raw_logging.h"
+#include "absl/numeric/internal/representation.h"
#include "absl/random/internal/chi_square.h"
#include "absl/random/internal/distribution_test_util.h"
#include "absl/random/internal/pcg_engine.h"
@@ -42,7 +44,15 @@ namespace {
template <typename IntType>
class BetaDistributionInterfaceTest : public ::testing::Test {};
-using RealTypes = ::testing::Types<float, double, long double>;
+// double-double arithmetic is not supported well by either GCC or Clang; see
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99048,
+// https://bugs.llvm.org/show_bug.cgi?id=49131, and
+// https://bugs.llvm.org/show_bug.cgi?id=49132. Don't bother running these tests
+// with double doubles until compiler support is better.
+using RealTypes =
+ std::conditional<absl::numeric_internal::IsDoubleDouble(),
+ ::testing::Types<float, double>,
+ ::testing::Types<float, double, long double>>::type;
TYPED_TEST_CASE(BetaDistributionInterfaceTest, RealTypes);
TYPED_TEST(BetaDistributionInterfaceTest, SerializeTest) {
@@ -53,9 +63,6 @@ TYPED_TEST(BetaDistributionInterfaceTest, SerializeTest) {
const TypeParam kLargeA =
std::exp(std::log((std::numeric_limits<TypeParam>::max)()) -
std::log(std::log((std::numeric_limits<TypeParam>::max)())));
- const TypeParam kLargeAPPC = std::exp(
- std::log((std::numeric_limits<TypeParam>::max)()) -
- std::log(std::log((std::numeric_limits<TypeParam>::max)())) - 10.0f);
using param_type = typename absl::beta_distribution<TypeParam>::param_type;
constexpr int kCount = 1000;
@@ -76,9 +83,6 @@ TYPED_TEST(BetaDistributionInterfaceTest, SerializeTest) {
kLargeA, //
std::nextafter(kLargeA, TypeParam(0)), //
std::nextafter(kLargeA, std::numeric_limits<TypeParam>::max()),
- kLargeAPPC, //
- std::nextafter(kLargeAPPC, TypeParam(0)),
- std::nextafter(kLargeAPPC, std::numeric_limits<TypeParam>::max()),
// Boundary cases.
std::numeric_limits<TypeParam>::max(),
std::numeric_limits<TypeParam>::epsilon(),
@@ -125,28 +129,6 @@ TYPED_TEST(BetaDistributionInterfaceTest, SerializeTest) {
ss >> after;
-#if defined(__powerpc64__) || defined(__PPC64__) || defined(__powerpc__) || \
- defined(__ppc__) || defined(__PPC__)
- if (std::is_same<TypeParam, long double>::value) {
- // Roundtripping floating point values requires sufficient precision
- // to reconstruct the exact value. It turns out that long double
- // has some errors doing this on ppc.
- if (alpha <= std::numeric_limits<double>::max() &&
- alpha >= std::numeric_limits<double>::lowest()) {
- EXPECT_EQ(static_cast<double>(before.alpha()),
- static_cast<double>(after.alpha()))
- << ss.str();
- }
- if (beta <= std::numeric_limits<double>::max() &&
- beta >= std::numeric_limits<double>::lowest()) {
- EXPECT_EQ(static_cast<double>(before.beta()),
- static_cast<double>(after.beta()))
- << ss.str();
- }
- continue;
- }
-#endif
-
EXPECT_EQ(before.alpha(), after.alpha());
EXPECT_EQ(before.beta(), after.beta());
EXPECT_EQ(before, after) //
diff --git a/absl/random/exponential_distribution_test.cc b/absl/random/exponential_distribution_test.cc
index 5a8afde5..af11d61c 100644
--- a/absl/random/exponential_distribution_test.cc
+++ b/absl/random/exponential_distribution_test.cc
@@ -30,6 +30,7 @@
#include "gtest/gtest.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/base/macros.h"
+#include "absl/numeric/internal/representation.h"
#include "absl/random/internal/chi_square.h"
#include "absl/random/internal/distribution_test_util.h"
#include "absl/random/internal/pcg_engine.h"
@@ -47,7 +48,15 @@ using absl::random_internal::kChiSquared;
template <typename RealType>
class ExponentialDistributionTypedTest : public ::testing::Test {};
-using RealTypes = ::testing::Types<float, double, long double>;
+// double-double arithmetic is not supported well by either GCC or Clang; see
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99048,
+// https://bugs.llvm.org/show_bug.cgi?id=49131, and
+// https://bugs.llvm.org/show_bug.cgi?id=49132. Don't bother running these tests
+// with double doubles until compiler support is better.
+using RealTypes =
+ std::conditional<absl::numeric_internal::IsDoubleDouble(),
+ ::testing::Types<float, double>,
+ ::testing::Types<float, double, long double>>::type;
TYPED_TEST_CASE(ExponentialDistributionTypedTest, RealTypes);
TYPED_TEST(ExponentialDistributionTypedTest, SerializeTest) {
@@ -126,23 +135,6 @@ TYPED_TEST(ExponentialDistributionTypedTest, SerializeTest) {
ss >> after;
-#if defined(__powerpc64__) || defined(__PPC64__) || defined(__powerpc__) || \
- defined(__ppc__) || defined(__PPC__)
- if (std::is_same<TypeParam, long double>::value) {
- // Roundtripping floating point values requires sufficient precision to
- // reconstruct the exact value. It turns out that long double has some
- // errors doing this on ppc, particularly for values
- // near {1.0 +/- epsilon}.
- if (lambda <= std::numeric_limits<double>::max() &&
- lambda >= std::numeric_limits<double>::lowest()) {
- EXPECT_EQ(static_cast<double>(before.lambda()),
- static_cast<double>(after.lambda()))
- << ss.str();
- }
- continue;
- }
-#endif
-
EXPECT_EQ(before.lambda(), after.lambda()) //
<< ss.str() << " " //
<< (ss.good() ? "good " : "") //
diff --git a/absl/random/gaussian_distribution_test.cc b/absl/random/gaussian_distribution_test.cc
index 2aa7caf4..c0bac2b0 100644
--- a/absl/random/gaussian_distribution_test.cc
+++ b/absl/random/gaussian_distribution_test.cc
@@ -21,12 +21,14 @@
#include <iterator>
#include <random>
#include <string>
+#include <type_traits>
#include <vector>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/base/macros.h"
+#include "absl/numeric/internal/representation.h"
#include "absl/random/internal/chi_square.h"
#include "absl/random/internal/distribution_test_util.h"
#include "absl/random/internal/sequence_urbg.h"
@@ -43,7 +45,15 @@ using absl::random_internal::kChiSquared;
template <typename RealType>
class GaussianDistributionInterfaceTest : public ::testing::Test {};
-using RealTypes = ::testing::Types<float, double, long double>;
+// double-double arithmetic is not supported well by either GCC or Clang; see
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99048,
+// https://bugs.llvm.org/show_bug.cgi?id=49131, and
+// https://bugs.llvm.org/show_bug.cgi?id=49132. Don't bother running these tests
+// with double doubles until compiler support is better.
+using RealTypes =
+ std::conditional<absl::numeric_internal::IsDoubleDouble(),
+ ::testing::Types<float, double>,
+ ::testing::Types<float, double, long double>>::type;
TYPED_TEST_CASE(GaussianDistributionInterfaceTest, RealTypes);
TYPED_TEST(GaussianDistributionInterfaceTest, SerializeTest) {
@@ -129,29 +139,6 @@ TYPED_TEST(GaussianDistributionInterfaceTest, SerializeTest) {
ss >> after;
-#if defined(__powerpc64__) || defined(__PPC64__) || defined(__powerpc__) || \
- defined(__ppc__) || defined(__PPC__)
- if (std::is_same<TypeParam, long double>::value) {
- // Roundtripping floating point values requires sufficient precision
- // to reconstruct the exact value. It turns out that long double
- // has some errors doing this on ppc, particularly for values
- // near {1.0 +/- epsilon}.
- if (mean <= std::numeric_limits<double>::max() &&
- mean >= std::numeric_limits<double>::lowest()) {
- EXPECT_EQ(static_cast<double>(before.mean()),
- static_cast<double>(after.mean()))
- << ss.str();
- }
- if (stddev <= std::numeric_limits<double>::max() &&
- stddev >= std::numeric_limits<double>::lowest()) {
- EXPECT_EQ(static_cast<double>(before.stddev()),
- static_cast<double>(after.stddev()))
- << ss.str();
- }
- continue;
- }
-#endif
-
EXPECT_EQ(before.mean(), after.mean());
EXPECT_EQ(before.stddev(), after.stddev()) //
<< ss.str() << " " //
diff --git a/absl/random/uniform_real_distribution_test.cc b/absl/random/uniform_real_distribution_test.cc
index 8cf874d6..18bcd3bc 100644
--- a/absl/random/uniform_real_distribution_test.cc
+++ b/absl/random/uniform_real_distribution_test.cc
@@ -20,11 +20,13 @@
#include <random>
#include <sstream>
#include <string>
+#include <type_traits>
#include <vector>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/internal/raw_logging.h"
+#include "absl/numeric/internal/representation.h"
#include "absl/random/internal/chi_square.h"
#include "absl/random/internal/distribution_test_util.h"
#include "absl/random/internal/pcg_engine.h"
@@ -55,7 +57,15 @@ namespace {
template <typename RealType>
class UniformRealDistributionTest : public ::testing::Test {};
-using RealTypes = ::testing::Types<float, double, long double>;
+// double-double arithmetic is not supported well by either GCC or Clang; see
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99048,
+// https://bugs.llvm.org/show_bug.cgi?id=49131, and
+// https://bugs.llvm.org/show_bug.cgi?id=49132. Don't bother running these tests
+// with double doubles until compiler support is better.
+using RealTypes =
+ std::conditional<absl::numeric_internal::IsDoubleDouble(),
+ ::testing::Types<float, double>,
+ ::testing::Types<float, double, long double>>::type;
TYPED_TEST_SUITE(UniformRealDistributionTest, RealTypes);
diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index 5efaf896..123b5efb 100644
--- a/absl/strings/BUILD.bazel
+++ b/absl/strings/BUILD.bazel
@@ -709,6 +709,7 @@ cc_library(
"//absl/meta:type_traits",
"//absl/numeric:bits",
"//absl/numeric:int128",
+ "//absl/numeric:representation",
"//absl/types:optional",
"//absl/types:span",
],
diff --git a/absl/strings/CMakeLists.txt b/absl/strings/CMakeLists.txt
index 12f322a9..3b7ae639 100644
--- a/absl/strings/CMakeLists.txt
+++ b/absl/strings/CMakeLists.txt
@@ -410,6 +410,7 @@ absl_cc_library(
absl::strings
absl::config
absl::core_headers
+ absl::numeric_representation
absl::type_traits
absl::int128
absl::span
diff --git a/absl/strings/internal/str_format/float_conversion.cc b/absl/strings/internal/str_format/float_conversion.cc
index 2b1fd8cb..b1c40684 100644
--- a/absl/strings/internal/str_format/float_conversion.cc
+++ b/absl/strings/internal/str_format/float_conversion.cc
@@ -29,6 +29,7 @@
#include "absl/meta/type_traits.h"
#include "absl/numeric/bits.h"
#include "absl/numeric/int128.h"
+#include "absl/numeric/internal/representation.h"
#include "absl/strings/numbers.h"
#include "absl/types/optional.h"
#include "absl/types/span.h"
@@ -39,6 +40,8 @@ namespace str_format_internal {
namespace {
+using ::absl::numeric_internal::IsDoubleDouble;
+
// The code below wants to avoid heap allocations.
// To do so it needs to allocate memory on the stack.
// `StackArray` will allocate memory on the stack in the form of a uint32_t
@@ -112,13 +115,6 @@ inline uint64_t DivideBy10WithCarry(uint64_t *v, uint64_t carry) {
return next_carry % divisor;
}
-constexpr bool IsDoubleDouble() {
- // This is the `double-double` representation of `long double`.
- // We do not handle it natively. Fallback to snprintf.
- return std::numeric_limits<long double>::digits ==
- 2 * std::numeric_limits<double>::digits;
-}
-
using MaxFloatType =
typename std::conditional<IsDoubleDouble(), double, long double>::type;
@@ -1404,6 +1400,8 @@ bool FloatToSink(const Float v, const FormatConversionSpecImpl &conv,
bool ConvertFloatImpl(long double v, const FormatConversionSpecImpl &conv,
FormatSinkImpl *sink) {
if (IsDoubleDouble()) {
+ // This is the `double-double` representation of `long double`. We do not
+ // handle it natively. Fallback to snprintf.
return FallbackToSnprintf(v, conv, sink);
}