[all-commits] [llvm/llvm-project] aba80d: [llvm-libc] Add memory function benchmarks

[Guillaume Chatelet via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: aba80d0734d1bc876395ad048462534618d25ca8
      https://github.com/llvm/llvm-project/commit/aba80d0734d1bc876395ad048462534618d25ca8
  Author: Guillaume Chatelet <gchatelet at google.com>
  Date:   2020-01-24 (Fri, 24 Jan 2020)

  Changed paths:
    M libc/utils/CMakeLists.txt
    M libc/utils/HdrGen/CMakeLists.txt
    A libc/utils/benchmarks/CMakeLists.txt
    A libc/utils/benchmarks/JSON.cpp
    A libc/utils/benchmarks/JSON.h
    A libc/utils/benchmarks/JSONTest.cpp
    A libc/utils/benchmarks/LibcBenchmark.cpp
    A libc/utils/benchmarks/LibcBenchmark.h
    A libc/utils/benchmarks/LibcBenchmarkTest.cpp
    A libc/utils/benchmarks/LibcMemoryBenchmark.cpp
    A libc/utils/benchmarks/LibcMemoryBenchmark.h
    A libc/utils/benchmarks/LibcMemoryBenchmarkMain.cpp
    A libc/utils/benchmarks/LibcMemoryBenchmarkMain.h
    A libc/utils/benchmarks/LibcMemoryBenchmarkTest.cpp
    A libc/utils/benchmarks/Memcmp.cpp
    A libc/utils/benchmarks/Memcpy.cpp
    A libc/utils/benchmarks/Memset.cpp
    A libc/utils/benchmarks/RATIONALE.md
    A libc/utils/benchmarks/README.md
    A libc/utils/benchmarks/configuration_big.json
    A libc/utils/benchmarks/configuration_small.json
    A libc/utils/benchmarks/render.py3

  Log Message:
  -----------
  [llvm-libc] Add memory function benchmarks

Summary:
This patch adds a benchmarking infrastructure for llvm-libc memory functions.

In a nutshell, the code can benchmark small and large buffers for the memcpy, memset and memcmp functions.
It also produces graphs of size vs latency by running targets of the form `render-libc-{memcpy|memset|memcmp}-benchmark-{small|big}`.

The configurations are provided as JSON files and the benchmark also produces a JSON file.
This file is then parsed and rendered as a PNG file via the `render.py` script (make sure to run `pip3 install matplotlib scipy numpy`).
The script can take several JSON files as input and will superimpose the curves if they are from the same host.

TODO:
 - The code benchmarks whatever is available on the host but should be configured to benchmark the -to be added- llvm-libc memory functions.
 - Add a README file with instructions and rationale.
 - Produce scores to track the performance of the functions over time to allow for regression detection.

Reviewers: sivachandra, ckennelly

Subscribers: mgorny, MaskRay, libc-commits

Tags: #libc-project

Differential Revision: https://reviews.llvm.org/D72516