| commit | 5ed77665c4d697f657fa1362b5a482450f858cdc | [log] [tgz] |
|---|---|---|
| author | Abseil Team <absl-team@google.com> | Mon Mar 14 08:43:59 2022 -0700 |
| committer | Andy Getz <durandal@google.com> | Mon Mar 14 12:14:03 2022 -0400 |
| tree | 85ce8fd99e4e0418b1d48c14611dc4b0a1e7ec73 | |
| parent | c5a424a2a21005660b182516eb7a079cd8021699 [diff] |
Export of internal Abseil changes -- d3b99682554d339c42556680f4d65f83226005e2 by Martijn Vels <mvels@google.com>: Inline CycleClock code and remove branch for x86 CycleClockSource function This CL removes the relaxed load for x86 as there is no acquire price to pay on x86. It inlines the UnscaledCycleClock::Now() which is a single RTDSC op for x86, and likewise inlines CycleClock::Now() for x86. The inlining should mostly have secondary benefits such as reducing spills on outlined calls. LTO may eventually hoist these functions inline for the hotspots, but it doesn't hurt to default inline this for all builds and let the compiler decide on the first pass. The perlab benchmark is noisy for the plain BM_Now, but the other benchmarks and the run on my local machine are clear. ------------- Local Benchy Benchmark name old cpu/op new cpu/op delta BM_Now 3.41ns ± 1% 2.30ns ± 2% -32.52% (p=0.000 n=50+50) BM_NowWithRegisterPresure 4.96ns ± 2% 4.19ns ± 2% -15.57% (p=0.000 n=56+55) BM_NowWithCallback 3.30ns ± 2% 1.91ns ± 2% -42.00% (p=0.000 n=47+60) ------------- Perflab Benchy Benchmark name old cpu/op new cpu/op delta BM_Now 8.20ns ±13% 4.32ns ±83% ~ (p=0.413 n=4+5) BM_NowWithRegisterPresure 7.91ns ± 1% 3.68ns ± 2% -53.45% (p=0.029 n=4+4) BM_NowWithCallback 2.66ns ±13% 1.58ns ± 0% -40.51% (p=0.008 n=5+5) PiperOrigin-RevId: 434474766 Change-Id: I991d987ae9233e50f09606c874055cf4c5a56300 -- b38330686a0af176a2679163e4d2fa1b90e2f667 by Laramie Leavitt <lar@google.com>: Style, comment, and test updates * Remove a redundant assert in uniform_real_distribution. * Update comment in internal/generate_real.h * Style updates to uniform_real_distribution_test mainly replacing TypeParam with real_type, using aliases for some limits, etc. * Add a few more minor tests. PiperOrigin-RevId: 433902174 Change-Id: Id75be8e24be2fb8f6aea05feec13e3ef320a7254 -- ab2da6047ff7f5dae3add3779fcddf73b03feabf by Abseil Team <absl-team@google.com>: Remove declaration of method whose definition was previously removed. PiperOrigin-RevId: 433507828 Change-Id: I0130b689813125250f7de2664e767e181f676c89 -- df0c87f4ec2c010691931c1bef9d26470a6e63a2 by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 433289136 Change-Id: Iba157dc83ed99dafd17a2223d2504e49f8afbb9e -- 7445fa312f2995772900eda82467325b3401a17d by Martijn Vels <mvels@google.com>: Optimize CordReader logic now that CONCAT is removed This CL cleans up various helper functions and logic remaining from previous complex CONCAT logic that is no longer needed, simplifying the CordReader logic. PiperOrigin-RevId: 433208748 Change-Id: I5f7b1883573c44e7c6f8af12c3cddbd197cb134d GitOrigin-RevId: d3b99682554d339c42556680f4d65f83226005e2
The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++11) designed to augment the C++ standard library.
Abseil is an open-source collection of C++ library code designed to augment the C++ standard library. The Abseil library code is collected from Google's own C++ code base, has been extensively tested and used in production, and is the same code we depend on in our daily coding lives.
In some cases, Abseil provides pieces missing from the C++ standard; in others, Abseil provides alternatives to the standard for special needs we've found through usage in the Google code base. We denote those cases clearly within the library code we provide you.
Abseil is not meant to be a competitor to the standard library; we've just found that many of these utilities serve a purpose within our code base, and we now want to provide those resources to the C++ community as a whole.
If you want to just get started, make sure you at least run through the Abseil Quickstart. The Quickstart contains information about setting up your development environment, downloading the Abseil code, running tests, and getting a simple binary working.
Bazel and CMake are the official build systems for Abseil.
See the quickstart for more information on building Abseil using the Bazel build system.
If you require CMake support, please check the CMake build instructions and CMake Quickstart.
Abseil is officially supported on many platforms. See the Abseil platform support guide for details on supported operating systems, compilers, CPUs, etc.
Abseil contains the following C++ library components:
base Abseil Fundamentals base library contains initialization code and other code which all other Abseil code depends on. Code within base may not depend on any other code (other than the C++ standard library).algorithm algorithm library contains additions to the C++ <algorithm> library and container-based versions of such algorithms.cleanup cleanup library contains the control-flow-construct-like type absl::Cleanup which is used for executing a callback on scope exit.container container library contains additional STL-style containers, including Abseil's unordered “Swiss table” containers.debugging debugging library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.hash hash library contains the hashing framework and default hash functor implementations for hashable types in Abseil.memory memory library contains C++11-compatible versions of std::make_unique() and related memory management facilities.meta meta library contains C++11-compatible versions of type checks available within C++14 and C++17 versions of the C++ <type_traits> library.numeric numeric library contains C++11-compatible 128-bit integers.profiling profiling library contains utility code for profiling C++ entities. It is currently a private dependency of other Abseil libraries.status status contains abstractions for error handling, specifically absl::Status and absl::StatusOr<T>.strings strings library contains a variety of strings routines and utilities, including a C++11-compatible version of the C++17 std::string_view type.synchronization synchronization library contains concurrency primitives (Abseil's absl::Mutex class, an alternative to std::mutex) and a variety of synchronization abstractions.time time library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.types types library contains non-container utility types, like a C++11-compatible version of the C++17 std::optional type.utility utility library contains utility and helper code.Abseil recommends users “live-at-head” (update to the latest commit from the master branch as often as possible). However, we realize this philosophy doesn't work for every project, so we also provide Long Term Support Releases to which we backport fixes for severe bugs. See our release management document for more details.
The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
For more information about Abseil: