The latest and most complete Java just-in-time compiler optimization methods in the whole network

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answer

JIT 对 Java 编译的基本单元是整个方法，通过对方法调用的计数统计，甄别出热点方法，编译为本地代码。
常见的优化手段有方法内联，去虚化，基于逃逸分析的栈上分配，锁消除和标量替换，字段读取存储优化，死代码消除，和循环优化相关的循环判断外提以及循环剥离，
向量化优化，还有HotSpot 虚拟机中的 intrinsic 机制。

method inlining

What is method inlining?

Under what circumstances will a method call be inlined?

deblurring

What is the devirtualization of the just-in-time compiler?

On-stack allocation, lock elimination and scalar replacement based on escape analysis

What do escape analysis, stack allocation, scalar replacement, synchronization elimination, and lock elimination refer to?

Field read storage optimization

What is the optimization of the just-in-time compiler for field read and store instructions?

Loop judgment and loop stripping related to loop optimization

Under what circumstances would loop code be optimized? What optimizations does the JVM have for looping code?

vectorization optimization

What is the vectorization optimization of the just-in-time compiler? What exactly are SIMDs?

Intrinsic mechanism in HotSpot virtual machine

What is intrinsic in HotSpot virtual machine?