Like simcop2387 said, a codegen backend which is focused on wasm will likely never be "made slow". Wasm is in the end close to a form of high level assembly. W

Like simcop2387 said, a codegen backend which is focused on wasm will likely never be "made slow". Wasm is in the end close to a form of high level assembly. Which means it is (should be) already preoptimized as much as needed/wanted/possible. Cranelift still needs to do some optimizations, especially wrt. platform specific aspects like register allocations and similar. In the end you don't want long load times when using wasm (at least in the web browser maybe in other places too). Through maybe in the future you might have some options to opt-in to some more time intensive optimizations for e.g. in browser gaming. But then rust could just not opt-in.