That's different. The rust toolchain is compiled by rust, and it relies on LLVM which can be compiled by GCC. But LLVM does not have a backend for every archite

That's different. The rust toolchain is compiled by rust, and it relies on LLVM which can be compiled by GCC. But LLVM does not have a backend for every architecture (or even if it does, it might require extra effort from the Rust compiler using it and they have not enabled support for _everything_). Thus not all architectures can be targets for Rust programs.