RustFFT

RustFFT is a high-performance, SIMD-accelerated FFT library written in pure Rust. It can compute FFTs of any size, including prime-number sizes, in O(nlogn) time.

Usage

// Perform a forward FFT of size 1234
use rustfft::{FftPlanner, num_complex::Complex};

let mut planner = FftPlanner::<f32>::new();
let fft = planner.plan_fft_forward(1234);

let mut buffer = vec![Complex{ re: 0.0, im: 0.0 }; 1234];

fft.process(&mut buffer);

SIMD acceleration

x86_64

RustFFT supports the AVX instruction set for increased performance. No special code is needed to activate AVX: Simply plan a FFT using the FftPlanner on a machine that supports the avx and fma CPU features, and RustFFT will automatically switch to faster AVX-accelerated algorithms.

For machines that do not have AVX, RustFFT also supports the SSE4.1 instruction set. As for AVX, this is enabled automatically when using the FftPlanner. If both AVX and SSE4.1 support are enabled, the planner will automatically choose the fastest available instruction set.

AArch64

RustFFT optionally supports the NEON instruction set in 64-bit Arm, AArch64. This optional feature requires a newer rustc version: Rustc 1.61. See Cargo Features below for more details.

WebAssembly

RustFFT additionally supports the fixed-width SIMD extension for WebAssembly. Unlike AVX, SSE, and NEON however, WASM does not allow dynamic feature detection as outlined here. Because of this, RustFFT does not automatically switch to WASM SIMD accelerated algorithms.

If you choose to opt into WASM SIMD, this feature will require a recent browser version (cf. Cargo Features).

Cargo Features

x86_64

The features avx and sse are enabled by default. On x86_64, these features enable compilation of AVX and SSE accelerated code.

Disabling them reduces compile time and binary size.

On other platforms than x86_64, these features do nothing and RustFFT will behave like they are not set.

AArch64

On AArch64, the neon feature enables compilation of Neon-accelerated code. This requires rustc 1.61 or newer, and is enabled by default.

On other platforms than AArch64, this feature does nothing and RustFFT will behave like it is not set.

WebAssembly

The feature wasm_simd is disabled by default. On the WASM platform, this feature enables compilation of WASM SIMD accelerated code. To compile with wasm_simd, you need rustc v1.61.0 or newer and a browser or runtime which supports fixed-width SIMD. If you run your SIMD accelerated code on an unsupported platform, WebAssembly will specify a trap leading to immediate execution cancelation.

On other platforms than WASM, this feature does nothing and RustFFT will behave like it is not set.

Stability/Future Breaking Changes

Version 5.0 contains several breaking API changes. heck out the Upgrade Guide for a walkthrough of the changes RustFFT 5.0 requires. In the interest of stability, we're committing to making no more breaking changes for 3 years, aka until 2024.

This policy has one exception: We currently re-export pre-1.0 versions of the num-complex and num-traits crates. In the interest of avoiding version fragmentation, we will keep up with these crates even if it requires major version bumps. When those crates release new major versions, we will upgrade as soon as possible, which will require a major version change of our own. In this situations, the version increase of num-complex/num-traits will be the only breaking change in the release.

Supported Rust Version

RustFFT requires rustc 1.61 or newer. Minor releases of RustFFT may upgrade the MSRV(minimum supported Rust version) to a newer version of rustc. However, if we need to increase the MSRV, the new Rust version must have been released at least six months ago.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Before submitting a PR, please make sure to run cargo fmt.