FFT.h File Reference

Fast Fourier Transform (Cooley-Tukey radix-2) with SIMD acceleration. More...

#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstring>
#include <numbers>
#include <type_traits>
#include <utility>
#include <vector>
#include <stdexcept>

Include dependency graph for FFT.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
class	dspark::FFTComplex< T >
	In-place Cooley-Tukey radix-2 DIT FFT for complex data. More...
class	dspark::FFTReal< T >
	FFT optimised for real-valued input signals (the common audio case). More...

Namespaces
namespace	dspark
	Main namespace for the DSPark framework.

Detailed Description

Fast Fourier Transform (Cooley-Tukey radix-2) with SIMD acceleration.

Provides forward and inverse FFT for both complex and real-valued signals. Optimised for power-of-two sizes typical in audio.

Performance features:

• SIMD-accelerated butterflies: SSE on x86-64 (float and double, with an SSE3 addsub fast path), NEON on ARM64.
• Unaligned-safe: forward()/inverse() accept pointers of any alignment; the SIMD paths use unaligned loads/stores, which cost the same as the aligned forms on every x86 CPU of the last decade.
• Dedicated first stage: the stride-2 stage has a twiddle of exactly 1, so it runs as a multiply-free pass.
• Zero allocations after construction; forward()/inverse() are noexcept.

Minimum x86-64 requirement: SSE2 (the x86-64 baseline). When SSE3 is available (any CPU from ~2005 onwards, or -msse3) the butterfly uses the native addsub instruction; otherwise a bit-identical XOR+add fallback runs.

Definition in file FFT.h.