CPython tried a register VM in 2012, here's what happened when I tried again

In 2012 Victor Stinner tried a register based bytecode for CPython. It got about 10% on pybench and was abandoned. Later attempts like RegCPython worked but never landed, because this introduced a lot of crashes in the virtual machine. I hit the same choice with Edge Python, a sandboxed Python subset in Rust and WebAssembly I posted about in July. Until last week it ran a stack VM and was 3x slower than CPython. This weekends I switched it to registers and all the math and loops came out the ...