Attribute Macro multiversion::target_clones

#[target_clones]

Provides automatic function multiversioning by compiling clones of the function for each target.

The proper function clone is invoked depending on runtime CPU feature detection. Priority is evaluated left-to-right, selecting the first matching target. If no matching target is found, a clone with no required features is called.

This attribute is useful when relying on the compiler to make optimizations, such as automatic vectorization. If you would like to dispatch hand-written optimized code, try the multiversion attribute instead.

Example

The function square runs with AVX or SSE compiler optimizations when detected on the CPU at runtime.

use multiversion::target_clones;

#[target_clones("[x86|x86_64]+avx", "x86+sse")]
fn square(x: &mut [f32]) {
    for v in x {
        *v *= *v;
    }
}

Static dispatching

The target_clones attribute provides a function that can be statically dispatched. Additionally, functions called inside the function may be statically dispatched. See static dispatching for more information.