> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ButterflyDIT4_4

> ButterflyDIT4_4

# ButterflyDIT4\_4

Don't use; internal use only.

## Syntax

```cpp theme={null}
void ButterflyDIT4_4(  
         XMVECTOR& r0,  
         XMVECTOR& r1,  
         XMVECTOR& r2,  
         XMVECTOR& r3,  
         XMVECTOR& i0,  
         XMVECTOR& i1,  
         XMVECTOR& i2,  
         XMVECTOR& i3,  
         const XMVECTOR* __restrict pUnityTableReal,  
         const XMVECTOR* __restrict pUnityTableImaginary,  
         size_t uStride,  
         const bool fLast  
)  
```

### Parameters

*r0*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*r1*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*r2*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*r3*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*i0*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*i1*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*i2*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*i3*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*pUnityTableReal*   \_In\_reads\_(uStride \* 4)\
Type: XMVECTOR\* \_\_restrict

Don't use; internal use only.

*pUnityTableImaginary*   \_In\_reads\_(uStride \* 4)\
Type: XMVECTOR\* \_\_restrict

Don't use; internal use only.

*uStride*   \_In\_\
Type: size\_t

Don't use; internal use only.

*fLast*   \_In\_\
Type: bool

Don't use; internal use only.

### Return value

Type: void

Don't use; internal use only.

## Remarks

Don't use; internal use only.

XDSP uses DirectXMath based digital signal processing (DSP) functions for audio, which they are primarily FFT. All buffer parameters must be 16-byte aligned. For more information about the DirectXMath API and library, see [DirectXMath](https://learn.microsoft.com/windows/win32/dxmath/directxmath-portal).

## Requirements

**Header:** xdsp.h

**Supported platforms:** XBOX One family consoles and XBOX Series consoles

## See also

[xdsp](/reference/audio/xdsp/xdsp_members)

[Game for Windows and the DirectX SDK blog](https://walbourn.github.io/xdsp-h-digital-signal-processing-helper-functions/)

[FFTInitializeUnityTable](/reference/audio/xdsp/functions/fftinitializeunitytable)


## Related topics

- [ButterflyDIT4_1](/reference/audio/xdsp/functions/butterflydit4_1.md)
- [FFT4](/reference/audio/xdsp/functions/fft4.md)
- [FFT](/reference/audio/xdsp/functions/fft.md)
- [FFT16](/reference/audio/xdsp/functions/fft16.md)
- [FFT8](/reference/audio/xdsp/functions/fft8.md)