Assembly Hall of Shame

(github.com)

60 points | by piotrgrabowski 1 hour ago

8 comments

  • spoocecow 5 minutes ago
    Oh wow, glad to see Chris Domas active online again!
  • TomatoCo 38 minutes ago
    This author also has other things like: A compiler that emits only `mov` instructions and another compiler that deliberately messes with the control flow so that, if disassembled, common debuggers will draw symbols like skulls or threats. https://github.com/xoreaxeaxeax/repsych
  • codeshaunted 36 minutes ago
    what im seeing from this chart is that we should be using the nop instruction for everything
    • bee_rider 23 minutes ago
      Well the best code is no code. Nop could be second best though.
  • vardump 51 minutes ago
    A great resource for any performance deoptimization.
  • achierius 35 minutes ago
    It'd be really interesting to see whether the winning (losing?) instructions/strategies would be different on other architectures. At least right now the top spot (`fxrstor64` on MMIO, starve PCIe) seems relatively architecture-independent, but maybe something about MMIO ordering rules on e.g. POWER would be different enough to change that -- or perhaps open up new avenues?

    I wonder what the actual limit on this `fxrstor64` is right now. If you can stall the PCIe bus for that long, then why not indefinitely? Certainly there's no forward progress guarantee here.

  • arn3n 39 minutes ago
    There’s definitely strategies here; A lot of the floating point operations use subnormals, and a lot of the worst instructions are slowed down by really, really fucking with MMIO.
  • 2_foos_in_a_bar 47 minutes ago
    [dead]
  • metadat 37 minutes ago
    It’s crazy how computers still seem to get perceivably slow every few years, given how many instructions can be executed in 1ms. Shameful, even..

    What’s that law called about programmers wasting all the compute on abstraction?

    • HappyPanacea 35 minutes ago
      The new windows notepad is a disgrace
    • LoganDark 35 minutes ago
      Huh? A millisecond is an eternity!