Export of internal Abseil changes

--
e2de21d54c02b6419c57c0f4e2a16b608deca260 by Evan Brown <ezb@google.com>:

Remove the InsertEnd benchmark.

This benchmark has significantly different possible behaviors that can result in misleading metrics. Specifically, we can have a case where we are deallocating the last node in the b-tree in the erase and then allocating a new node in the insert call repeatedly, whereas normally, we end up just inserting/erasing a value from the last node. Also, the name of the benchmark is misleading because it involves an erase and an insert, but the name only mentions the insert.

PiperOrigin-RevId: 360930639

--
51f6bb97b9cbdb809c31b77e93ce080ca3cba9ea by Benjamin Barenblat <bbaren@google.com>:

Stop testing with double-double random variables

On POWER, long double is often represented as a pair of doubles added
together (double-double arithmetic). We’ve already special-cased
double-double arithmetic in a number of tests, but compiler
bugs [1, 2, 3] have now triggered both false positives and false
negatives, which suggests testing with double doubles is unlikely to
yield useful signal. Remove the special casing and detect if we’re on a
double-double system; if so, just don’t test long doubles.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99048
[2] https://bugs.llvm.org/show_bug.cgi?id=49131
[3] https://bugs.llvm.org/show_bug.cgi?id=49132

PiperOrigin-RevId: 360793161

--
07fb4d7932c2f5d711c480f759dacb0be60f975e by Abseil Team <absl-team@google.com>:

internal change

PiperOrigin-RevId: 360712825
GitOrigin-RevId: e2de21d54c02b6419c57c0f4e2a16b608deca260
Change-Id: I98389b5a8789dcc8f35abc00c767e909181665f0

1 files changed, 11 insertions, 29 deletions

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)           //