# sub_sd(v128, v128)

> Subtract the lower double-precision (64-bit) floating-point element in "b" from the lower double-precision (64-bit) floating-point element in "a", store the result in the lower element of "dst", and copy the upper element from "a" to the upper element of "dst".

## Definition

* **Type:** Method
* **Namespace:** [Unity.Burst.Intrinsics](/engine/6000.6/script-reference/unity/burst/intrinsics.md)
* **Assembly:** UnityEngine.BurstModule

```csharp
public static v128 sub_sd(v128 a, v128 b)
```

### Parameters

**** (\[v128]\(/engine/6000.6/script-reference/unity/burst/intrinsics/v128)): Vector a**** (\[v128]\(/engine/6000.6/script-reference/unity/burst/intrinsics/v128)): Vector b

### Returns

| Type                                                                   | Description |
| ---------------------------------------------------------------------- | ----------- |
| [v128](/engine/6000.6/script-reference/unity/burst/intrinsics/v128.md) | Vector      |