Add lld benchmarking script. The purpose of this script is to measure the performance effect of an lld change in a statistically sound way, automating all the tedious parts of doing so. It copies the test case into /tmp as well as running the test binaries from /tmp to reduce the influence on the test machine's storage medium on the results. It accounts for measurement bias caused by binary layout (using the --randomize-section-padding flag to link the test binaries) and by environment variable size (implemented by hyperfine [1]). Runs of the base and test case are interleaved to account for environmental factors which may influence the result due to the passage of time. The results of running hyperfine are collected into a results.csv file in the output directory and may be analyzed by the user with a tool such as ministat. Requirements: Linux host, hyperfine [2] in $PATH, run from a build directory configured to use ninja and a recent version of lld that supports --randomize-section-padding, /tmp is tmpfs. [1] https://github.com/sharkdp/hyperfine/blob/3cedcc38d0c430cbf38b4364b441c43a938d2bf3/src/util/randomized_environment_offset.rs#L1 [2] https://github.com/sharkdp/hyperfine Reviewers: rnk, MaskRay, smithp35 Reviewed By: rnk Pull Request: https://github.com/llvm/llvm-project/pull/138367
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.