JEP 489: Vector API (Ninth Incubator)

🎯 What Is the Vector API?

The Vector API enables you to express vector computations in Java that are compiled at runtime to SIMD instructions, giving much better performance for certain numeric workloads — without writing native code.

It's part of the jdk.incubator.vector module and works best on CPUs that support SIMD (like AVX).

History

"We first proposed the Vector API in JEP 338, integrated into JDK 16 as an incubating API. We proposed further rounds of incubation in JEP 414 (integrated into JDK 17), JEP 417 (JDK 18), JEP 426 (JDK 19), JEP 438 (JDK 20), JEP 448 (JDK 21), JEP 460 (JDK 22), and JEP 469 (JDK 23)."

✅ Key Concepts

• Vector API: Exposes hardware-friendly operations (add, multiply, etc.) on arrays of primitives (int, float, etc.).

• VectorSpecies<T>: Describes the size and shape of a vector supported on the current hardware.

• HotSpot JIT: Automatically compiles vector operations to SIMD instructions (e.g., AVX on x86, SVE on ARM).

• Portable & Safe: Unlike hand-written native code, vector code stays within Java’s safety and portability model.

• Incubator Module: Available via jdk.incubator.vector, still evolving.

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🚀 Benefits

Benefit	Explanation
Performance Boost	Exploits SIMD hardware features automatically
Platform Adaptation	Adapts to CPU capabilities at runtime
Clean Java API	No JNI, no unsafe — all pure Java
Vectorized Loops	Ideal for math-heavy tasks (e.g., image, ML)