TIL: JEP 165 (Compiler Control) https://openjdk.org/jeps/165 lets you tune the JIT per method — disable vectorization, control inlining, print assembly, disable specific intrinsics, and more.
Example:
```json
[
{
"match": "com/example/MyClass.myMethod(I)V",
"c2": {
"Vectorize": false
}
}
]
```
Start with -XX:CompileCommandFile=directives.json
While writing a new book on SIMD and the Java Vector API I always wondered how to isolate auto-vectorization at the method level. Turns out there's a whole toolbox here.