A great resource for any performance deoptimization.
arn3n•10m 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.
TomatoCo•9m 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
metadat•7m ago
It’s crazy how computers still seem slow after 5-10 years, given how many instructions can be executed in less than 1ms. Shameful, even..
LoganDark•5m ago
Huh? A millisecond is an eternity!
HappyPanacea•5m ago
The new windows notepad is a disgrace
codeshaunted•7m ago
what im seeing from this chart is that we should be using the nop instruction for everything
achierius•5m 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.
vardump•21m ago