Performance Improvements of JIT Compilation
This section provides a performance comparison between interpreted-only mode and JIT compilation mode on loops with different operations. The JIT compiler improves performance a lot!
If you compare testing results between interpreted-only mode and JIT compilation mode,
you will see performance improvements produced by the JIT compiler.
This table provides execution time of different "int" loops per step in nanoseconds:
Empty loop 16 1
Assignment: x=i 14 2
Shift: x=i<<1 17 1
Add: x=i+i 17 1
Multipply: x=i*3 17 1
Divide: x=i/3 19 14
This table provides execution time of different "long" loops per step in nanoseconds:
Empty loop 25 2
Assignment: x=i 24 3
Shift: x=i<<1 30 4
Add: x=i+i 34 3
Multipply: x=i*3 38 4
Divide: x=i/3 53 24
- Do not turn off JIT compilation in your JVM!
- Avoid using "long" operations!
- Avoid using division operations!
Last update: 2010.
Table of Contents
About This Book
Downloading and Installing JDK 1.8.0 on Windows
Downloading and Installing JDK 1.7.0 on Windows
java.lang.Runtime Class - The JVM Instance
java.lang.System Class - The Operating System
ClassLoader Class - Class Loaders
Class Class - Class Reflections
Sun's JVM - Java HotSpot VM
JRockit JVM 28.2.7 by Oracle Corporation
JVM Runtime Data Areas
Memory Management and Garbage Collectors
Garbage Collection Tests
JVM Stack, Frame and Stack Overflow
Thread Testing Program and Result
CPU Impact of Multi-Thread Applications
I/O Impact of Multi-Thread Applications
CDS (Class Data Sharing)
Micro Benchmark Runner and JVM Options
Micro Benchmark Tests on "int" Operations
Micro Benchmark Tests on "long" Operations
►Micro Benchmark Tests in JIT Compilation Mode
"int" Loops with JIT Compilation
"long" Loops with JIT Compilation
►Performance Improvements of JIT Compilation
Micro Benchmark Tests on "float" and "double" Operations
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