Escape Analysis and the Allocation That Never Happened
C2 can delete an object entirely by proving it never escapes. Here is when that works, when it silently stops, and how to measure the difference.
jvm-internals
2 articles
What the JIT Actually Does to Your Hot Loop
Tiered compilation, on-stack replacement and inlining decide how your loop really runs. Here is how to read those decisions instead of guessing.