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-# Target features in practice
-
-Using `RUSTFLAGS` will allow the crate being compiled, as well as all its
-transitive dependencies to use certain target features.
-
-A tehnique used to avoid undefined behavior at runtime is to compile and
-ship multiple binaries, each compiled with a certain set of features.
-This might not be feasible in some cases, and can quickly get out of hand
-as more and more vector extensions are added to an architecture.
-
-Rust can be more flexible: you can build a single binary/library which automatically
-picks the best supported vector instructions depending on the host machine.
-The trick consists of monomorphizing parts of the code during building, and then
-using run-time feature detection to select the right code path when running.
-
-<!-- TODO
-Explain how to create efficient functions that dispatch to different
-implementations at run-time without issues (e.g. using `#[inline(always)]` for
-the impls, wrapping in `#[target_feature]`, and the wrapping those in a function
-that does run-time feature detection).
--->
-
-**NOTE** (x86 specific): because the AVX (256-bit) registers extend the existing
-SSE (128-bit) registers, mixing SSE and AVX instructions in a program can cause
-performance issues.
-
-The solution is to compile all code, even the code written with 128-bit vectors,
-with the AVX target feature enabled. This will cause the compiler to prefix the
-generated instructions with the [VEX] prefix.
-
-[VEX]: https://en.wikipedia.org/wiki/VEX_prefix