.NET CLR Jitting Documentation

The JIT compiler transforms Microsoft Intermediate Language (MSIL) into native machine code at runtime. This process optimizes execution based on the current environment, enabling .NET applications to run efficiently on diverse hardware.

1. Method call triggers JIT.
2. MSIL is retrieved from the assembly.
3. JIT compiles MSIL to native code.
4. Native code is cached for subsequent calls.

public int Add(int a, int b) => a + b;
// First call triggers JIT
int result = Add(2,3);

Adjust JIT behavior via runtime configuration or environment variables.

{
  "runtimeOptions": {
    "configProperties": {
      "System.GC.Server": true,
      "System.Runtime.TieredCompilation": false
    }
  }
}

• Use MethodImplOptions.AggressiveInlining for hot methods.
• Prefer structs for small data objects to reduce heap allocations.
• Enable tiered compilation for long-running services.