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Unity Engine

Marking code for Burst compilation

Read time 2 minutesLast updated 13 days ago
Apply the 
[BurstCompile]
 attribute to the parts of your code you want Burst to compile. You can apply the 
[BurstCompile]
attribute to the following:
  • Jobs: When you apply 
    [BurstCompile]
    to a job definition, Burst compiles everything within the job. For more information on jobs, refer to Job system.
  • Classes: Apply 
    [BurstCompile]
    to a class definition if the class contains static methods that are also marked with 
    [BurstCompile]
    . Burst can't compile the class itself but only its member methods.
  • Structs: Apply 
    [BurstCompile]
    to a regular (non-job) struct definition if the struct contains static methods that are also marked with 
    [BurstCompile]
    .
  • Static methods: Apply 
    [BurstCompile]
    to the method and its parent type. To work with dynamic functions that process data based on other data states, refer to Function pointers.
  • Assemblies: Apply 
    [BurstCompile]
    to an assembly to set options for all Burst jobs and function-pointers within the assembly. For more information, refer to Defining Burst options for an assembly.
Note
You don't always need to mark a method with the 
[BurstCompile]
attribute for Burst to compile it. Any method where the program execution switches from managed to Burst-compiled code is referred to as a Burst entry point. If a static entry point method is marked with 
[BurstCompile]
, Burst also compiles any methods it calls into, even if they're not marked 
[BurstCompile]
.

Configure Burst compilation with parameters

You can supply parameters to the 
[BurstCompile]
 attribute to modify aspects of compilation and improve Burst's performance. You can use attribute parameters to:
  • Use a different accuracy for math functions (for example, sin, cos).
  • Relax the order of math computations so that Burst can rearrange the floating point calculations.
  • Force a synchronous compilation of a job (only for just-in-time compilation).
For example, you can use the 
[BurstCompile]
attribute to change the floating precision and float mode of Burst as follows:
[BurstCompile(FloatPrecision.Medium, FloatMode.Fast)]
For more information on configuring precision and determinism in floating point calculations, refer to Float precision and determinism.

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