Pi4 TARGET_CPU option

  • I see that RPi4 is build with TARGET_CPU="cortex-a53"

    Is there a reason to not use TARGET_CPU="cortex-a72" ?


    Could this make SW decoding faster ?

  • Klojum

    Approved the thread.
  • Optimizing for cortex-a72 resulted in odd issues, see eg my comment here add support for Raspberry Pi 4 by HiassofT · Pull Request #3597 · LibreELEC/LibreELEC.tv · GitHub


    Could be (or have been) some compiler/optimizer bug.


    Other LE deveopers noticed similar issues on other devices as well so we stuck to cortex-a53 which works fine.


    It's hard to tell if optimizing for cortex-a72 would give any real-world performance improvements and as digging into possible compiler bugs isn't fun we haven't investigated that further.


    so long,


    Hias

  • Thanks for pointing to the bug report.


    I tried AV1 decoder ( libdav1d ) but I see it's almost fully optimized with NEON SIMD so it shouldn't really change anything.