Why is Rust slightly slower than C?

Re:Why is Rust slightly slower than C? by mlindner on Wednesday September 11, 2019 @10:34PM (#20947268)

Please don't answer the question if you don't know enough to answer it. Rust doesn't have exception handling. Rust doesn't have a runtime.

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Re:Why is Rust slightly slower than C? by maxk42 on Wednesday September 18, 2019 @03:13PM (#21008883)

Yes, rust has a runtime. Even most assemblers have runtimes these days.

Take a look at this: https://imgur.com/lPOPj1G

You see that difference? That's not rust producing less-efficient code. That's the more complex rust runtime.

Think it's an artifact of static linkage? Guess again.

https://imgur.com/KsrApXC

But IIRC rust doesn't statically link glibc by default.

So the difference in runtime overhead is more than 10x the machine code size. That doesn't translate to a 10x slowdown and a lot of that is probably baked-in optimization but rust certainly has a runtime and associated overhead and it has a lot larger runtime than C.

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