Package libcpucycles: Information

    Source package: libcpucycles
    Version: 20230115-alt1
    Build time:  Sep 26, 2023, 05:31 PM
    Category: Development/C
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    License: CC0
    Summary: Microlibrary for counting CPU cycles
    Description: 
    libcpucycles is a public-domain microlibrary for counting CPU
    cycles. Cycle counts are not as detailed as Falk diagrams but are the
    most precise timers available to typical software; they are central
    tools used in understanding and improving software performance.
    
    The libcpucycles API is simple: include <cpucycles.h>, call cpucycles()
    to receive a long long whenever desired, and link with -lcpucycles.
    
    Internally, libcpucycles understands machine-level cycle counters for
    amd64 (both PMC and TSC), arm32, arm64 (both PMC and VCT), mips64,
    ppc32, ppc64, riscv32, riscv64, s390x, sparc64, and x86. libcpucycles
    also understands four OS-level mechanisms, which give varying levels
    of accuracy: mach_absolute_time, perf_event, CLOCK_MONOTONIC, and,
    as a fallback, microsecond-resolution gettimeofday.
    
    When the program first calls cpucycles(), libcpucycles automatically
    benchmarks the available mechanisms and selects the mechanism that
    does the best job. Subsequent cpucycles() calls are thread-safe and
    very fast. An accompanying cpucycles-info program prints a summary of
    cycle-counter accuracy.
    
    For comparison, there is a simple-sounding __rdtsc() API provided by
    compilers, but this works only on Intel/AMD CPUs and is generally noisier
    than PMC. There is a __builtin_readcyclecounter() that works on more CPUs,
    but this works only with clang and has the same noise problems. Both
    of these mechanisms put the burden on the caller to figure out what can
    be done on other CPUs. Various packages include their own more portable
    abstraction layers for counting cycles (see, e.g., FFTW's cycle.h, used
    to automatically select from among multiple implementations provided by
    FFTW), but this creates per-package effort to keep up with the latest
    cycle counters. The goal of libcpucycles is to provide state-of-the-art
    cycle counting centrally for all packages to use.

    List of rpms provided by this srpm:
    libcpucycles (e2kv6, e2kv5, e2kv4, e2k)
    libcpucycles-debuginfo (e2kv6, e2kv5, e2kv4, e2k)
    libcpucycles-devel (e2kv6, e2kv5, e2kv4, e2k)
    libcpucycles-devel-debuginfo (e2kv6, e2kv5, e2kv4, e2k)

    Maintainer: Vitaly Chikunov

    List of contributors:
    Vitaly Chikunov

      1. python3

    Last changed


    Sept. 25, 2023 Vitaly Chikunov 20230115-alt1
    - Update to 20230115 (2023-01-16).
    Jan. 5, 2023 Vitaly Chikunov 20230105-alt1
    - First import 20230105 (2023-01-05).