Export of internal Abseil changes

--
049ac45508e335c6f010f2d28d71016b9fa65b4e by Derek Mauro <dmauro@google.com>:

Fix librt detection

PiperOrigin-RevId: 280207723

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6382c3a9fb2643af9dc031f92ca846c4a78e249c by Andy Getzendanner <durandal@google.com>:

Fix Conan builds

Import of https://github.com/abseil/abseil-cpp/pull/400

PiperOrigin-RevId: 280025424

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aebcd52b1686ac82663a8d0193b60d0122a43372 by Samuel Benzaquen <sbenza@google.com>:

Enable the assertion in the iterator's operator== and operator!=

PiperOrigin-RevId: 279998951

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5b61d909e2159ac6fd45e0e456818db1e725ecd1 by Derek Mauro <dmauro@google.com>:

Add best effort support for compiling much of Abseil with MinGW.
This involves disabling ABSL_ATTRIBUTE_WEAK and adding link flags.

A change to CCTZ is still necessary.

Tests were not run yet, but most of them now build.

PiperOrigin-RevId: 279966541

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4336f8b10cff906e2defdd7d1d449cde4907da5d by Abseil Team <absl-team@google.com>:

Add comments and relax memory orders in base_internal::CallOnceImpl.

Add a comment to document the memory order guarantee if
base_internal::SpinLockWait() is called and returns kOnceDone.

Add a comment for the load/store sequence in base_internal::CallOnceImpl
based on Mike Burrows' explanation.

The atomic load of 'control' in the #ifndef NDEBUG block does not need
std::memory_order_acquire. It can use std::memory_order_relaxed.

The atomic compare_exchange_strong of 'control' does not need
std::memory_order_acquire in the success case. It can use
std::memory_order_relaxed.
PiperOrigin-RevId: 279814155

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407de3a5e9af957cded54a136ca0468bde620d4d by Abseil Team <absl-team@google.com>:

Added a script to generate abseil.podspec from all BUILD.bazel files automatically.

PiperOrigin-RevId: 279811441

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26139497d4a363d6c7bc989c554da593e8819a07 by Derek Mauro <dmauro@google.com>:

Add missing copyright and Apache License to //absl/functional/BUILD.bazel

PiperOrigin-RevId: 279795227

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98ed625b02af6e5834edf52a920d8ca2dab4cd90 by Matt Kulukundis <kfm@google.com>:

Switch the implementation of hashtablez to *only* work on platforms that have a
PER_THREAD_TLS.

The old case is very slow (global mutex) and nobody collects data from that
configuration anyway.

PiperOrigin-RevId: 279775149

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07225900ef672c005c38f467ad3f92f38d0922b3 by Derek Mauro <dmauro@google.com>:

Remove the minumum glibc version check

PiperOrigin-RevId: 279750412

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ec09956a951b4f52228ecc81968b8db7ae19ed15 by Derek Mauro <dmauro@google.com>:

CMake only: link with -lrt to support older glibc versions

PiperOrigin-RevId: 279741661

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97b113fb2e8246f6152c36330ba13793b37154b6 by Xiaoyi Zhang <zhangxy@google.com>:

Internal change.

PiperOrigin-RevId: 279390188

--
ca8f72f2721546cc9b01bd01b2ea144962e6e0c5 by Andy Getzendanner <durandal@google.com>:

Expose PutTwoDigits for internal use within Abseil.

PiperOrigin-RevId: 279374239

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14c6384cc03bbdfdefd2e4b635f104af5dd7e026 by Derek Mauro <dmauro@google.com>:

Remove log_severity sources from the base target.
They are already compiled as part of a separate library.

PiperOrigin-RevId: 279372619

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3c5d926c718f8bf394e3bee87b6ba8d94601e0d3 by Abseil Team <absl-team@google.com>:

s/indepdent/independent/g in SimpleAtof's documentation.

PiperOrigin-RevId: 279350836

--
de2c44be8a8edf9efa1fe2007cba3564f3e5b0b8 by Abseil Team <absl-team@google.com>:

Internal change

PiperOrigin-RevId: 279346990

--
2ba078341423fcf6d0ba5ca1831f86570a26e615 by Samuel Benzaquen <sbenza@google.com>:

Add hash support for std::wstring, std::u16string and std::u32string.

PiperOrigin-RevId: 279320672

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3272d3ffcfa55283a04f90e5868701912da95ef7 by Andy Soffer <asoffer@google.com>:

Removing a bunch of __restricts that amount to no performance differences. One
of these is the cause of https://github.com/abseil/abseil-cpp/issues/396. In
particular, in one of the Vector128Store functions, restricts on two pointers
that were indeed aliased seems to be the root cause of the issues.

Closes #396

PiperOrigin-RevId: 279318999

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342f338ab31cc24344d5de8f28cf455bbb629a17 by Jorg Brown <jorg@google.com>:

Support uint128 in SimpleAtoi

PiperOrigin-RevId: 279234038

--
81cb0a04cf2dc4515d303679fc60968712191571 by Derek Mauro <dmauro@google.com>:

Change the check for futex availability to support older Linux systems

PiperOrigin-RevId: 279147079

--
cb4ca4aa4c8d2d710a5d483c56c4ce4f979e14b1 by Abseil Team <absl-team@google.com>:

Add IWYU pragma: export for int128 .inc files.

PiperOrigin-RevId: 279107098

--
b8df86ef610c366729f07326c726f3e34817b4dd by Abseil Team <absl-team@google.com>:

An optimization for Waiter::Post() in the SEM waiter mode.

Like the FUTEX waiter mode, Waiter::Post() only needs to call Poke() if
it incremented the atomic variable from 0.

PiperOrigin-RevId: 279086133
GitOrigin-RevId: 049ac45508e335c6f010f2d28d71016b9fa65b4e
Change-Id: I4c1a4073fff62cb6a1fcb1c104aa7d62dad588c2

1 files changed, 16 insertions, 32 deletions

diff --git a/absl/random/internal/randen_hwaes.cc b/absl/random/internal/randen_hwaes.cc
index 7d5b2b74128b..6cc36fd39b5e 100644
--- a/absl/random/internal/randen_hwaes.cc
+++ b/absl/random/internal/randen_hwaes.cc
@@ -159,13 +159,11 @@ inline ABSL_TARGET_CRYPTO Vector128 ReverseBytes(const Vector128& v) {
 // WARNING: these load/store in native byte order. It is OK to load and then
 // store an unchanged vector, but interpreting the bits as a number or input
 // to AES will have undefined results.
-inline ABSL_TARGET_CRYPTO Vector128
-Vector128Load(const void* ABSL_RANDOM_INTERNAL_RESTRICT from) {
+inline ABSL_TARGET_CRYPTO Vector128 Vector128Load(const void* from) {
   return vec_vsx_ld(0, reinterpret_cast<const Vector128*>(from));
 }
 
-inline ABSL_TARGET_CRYPTO void Vector128Store(
-    const Vector128& v, void* ABSL_RANDOM_INTERNAL_RESTRICT to) {
+inline ABSL_TARGET_CRYPTO void Vector128Store(const Vector128& v, void* to) {
   vec_vsx_st(v, 0, reinterpret_cast<Vector128*>(to));
 }
 
@@ -177,8 +175,7 @@ inline ABSL_TARGET_CRYPTO Vector128 AesRound(const Vector128& state,
 }
 
 // Enables native loads in the round loop by pre-swapping.
-inline ABSL_TARGET_CRYPTO void SwapEndian(
-    uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT state) {
+inline ABSL_TARGET_CRYPTO void SwapEndian(uint64_t* state) {
   using absl::random_internal::RandenTraits;
   constexpr size_t kLanes = 2;
   constexpr size_t kFeistelBlocks = RandenTraits::kFeistelBlocks;
@@ -230,13 +227,11 @@ using Vector128 = uint8x16_t;
 
 namespace {
 
-inline ABSL_TARGET_CRYPTO Vector128
-Vector128Load(const void* ABSL_RANDOM_INTERNAL_RESTRICT from) {
+inline ABSL_TARGET_CRYPTO Vector128 Vector128Load(const void* from) {
   return vld1q_u8(reinterpret_cast<const uint8_t*>(from));
 }
 
-inline ABSL_TARGET_CRYPTO void Vector128Store(
-    const Vector128& v, void* ABSL_RANDOM_INTERNAL_RESTRICT to) {
+inline ABSL_TARGET_CRYPTO void Vector128Store(const Vector128& v, void* to) {
   vst1q_u8(reinterpret_cast<uint8_t*>(to), v);
 }
 
@@ -254,8 +249,7 @@ inline ABSL_TARGET_CRYPTO Vector128 AesRound(const Vector128& state,
   return vaesmcq_u8(vaeseq_u8(state, uint8x16_t{})) ^ round_key;
 }
 
-inline ABSL_TARGET_CRYPTO void SwapEndian(
-    uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT) {}
+inline ABSL_TARGET_CRYPTO void SwapEndian(uint64_t*) {}
 
 }  // namespace
 
@@ -283,15 +277,12 @@ class Vector128 {
   __m128i data_;
 };
 
-inline ABSL_TARGET_CRYPTO Vector128
-Vector128Load(const void* ABSL_RANDOM_INTERNAL_RESTRICT from) {
+inline ABSL_TARGET_CRYPTO Vector128 Vector128Load(const void* from) {
   return Vector128(_mm_load_si128(reinterpret_cast<const __m128i*>(from)));
 }
 
-inline ABSL_TARGET_CRYPTO void Vector128Store(
-    const Vector128& v, void* ABSL_RANDOM_INTERNAL_RESTRICT to) {
-  _mm_store_si128(reinterpret_cast<__m128i * ABSL_RANDOM_INTERNAL_RESTRICT>(to),
-                  v.data());
+inline ABSL_TARGET_CRYPTO void Vector128Store(const Vector128& v, void* to) {
+  _mm_store_si128(reinterpret_cast<__m128i*>(to), v.data());
 }
 
 // One round of AES. "round_key" is a public constant for breaking the
@@ -304,8 +295,7 @@ inline ABSL_TARGET_CRYPTO Vector128 AesRound(const Vector128& state,
   return Vector128(_mm_aesenc_si128(state.data(), round_key.data()));
 }
 
-inline ABSL_TARGET_CRYPTO void SwapEndian(
-    uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT) {}
+inline ABSL_TARGET_CRYPTO void SwapEndian(uint64_t*) {}
 
 }  // namespace
 
@@ -402,8 +392,7 @@ constexpr size_t kLanes = 2;
 
 // Block shuffles applies a shuffle to the entire state between AES rounds.
 // Improved odd-even shuffle from "New criterion for diffusion property".
-inline ABSL_TARGET_CRYPTO void BlockShuffle(
-    uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT state) {
+inline ABSL_TARGET_CRYPTO void BlockShuffle(uint64_t* state) {
   static_assert(kFeistelBlocks == 16, "Expecting 16 FeistelBlocks.");
 
   constexpr size_t shuffle[kFeistelBlocks] = {7,  2, 13, 4,  11, 8,  3, 6,
@@ -452,8 +441,7 @@ inline ABSL_TARGET_CRYPTO void BlockShuffle(
 // parallel hides the 7-cycle AESNI latency on HSW. Note that the Feistel
 // XORs are 'free' (included in the second AES instruction).
 inline ABSL_TARGET_CRYPTO const u64x2* FeistelRound(
-    uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT state,
-    const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+    uint64_t* state, const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   static_assert(kFeistelBlocks == 16, "Expecting 16 FeistelBlocks.");
 
   // MSVC does a horrible job at unrolling loops.
@@ -513,8 +501,7 @@ inline ABSL_TARGET_CRYPTO const u64x2* FeistelRound(
 // 2^64 queries if the round function is a PRF. This is similar to the b=8 case
 // of Simpira v2, but more efficient than its generic construction for b=16.
 inline ABSL_TARGET_CRYPTO void Permute(
-    const void* ABSL_RANDOM_INTERNAL_RESTRICT keys,
-    uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT state) {
+    const void* ABSL_RANDOM_INTERNAL_RESTRICT keys, uint64_t* state) {
   const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys128 =
       static_cast<const u64x2*>(keys);
 
@@ -544,10 +531,8 @@ const void* ABSL_TARGET_CRYPTO RandenHwAes::GetKeys() {
 // NOLINTNEXTLINE
 void ABSL_TARGET_CRYPTO RandenHwAes::Absorb(const void* seed_void,
                                             void* state_void) {
-  uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT state =
-      reinterpret_cast<uint64_t*>(state_void);
-  const uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT seed =
-      reinterpret_cast<const uint64_t*>(seed_void);
+  auto* state = static_cast<uint64_t*>(state_void);
+  const auto* seed = static_cast<const uint64_t*>(seed_void);
 
   constexpr size_t kCapacityBlocks = kCapacityBytes / sizeof(Vector128);
   constexpr size_t kStateBlocks = kStateBytes / sizeof(Vector128);
@@ -623,8 +608,7 @@ void ABSL_TARGET_CRYPTO RandenHwAes::Generate(const void* keys,
                                               void* state_void) {
   static_assert(kCapacityBytes == sizeof(Vector128), "Capacity mismatch");
 
-  uint64_t* ABSL_RANDOM_INTERNAL_RESTRICT state =
-      reinterpret_cast<uint64_t*>(state_void);
+  auto* state = static_cast<uint64_t*>(state_void);
 
   const Vector128 prev_inner = Vector128Load(state);