Re:A Tour of Safe Tracing GC Designs in Rust
by xfer on Saturday June 19, 2021 @02:00PM
(#27562734)
Isn't using bottom bit is how most runtimes represent their ints taking advantage of the fact that gc pointers are aligned? This is common practice afaiu.
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Re:A Tour of Safe Tracing GC Designs in Rust
by tialaramex on Saturday June 19, 2021 @06:29PM
(#27565088)
Sure, but for the bottom bit, 64-bit addressing doesn't come into it. If you only want to steal bits at the bottom and have pointers with greater than single byte alignment this worked just fine on a 32-bit CPU already.
I was reacting to the claim that this mitigates the overhead (larger pointer size) of 64-bit addressing. You can steal bits at the top but it's probably a bad idea.