编译器优化:Java字节码 [英] Compiler optimization: Java bytecode
问题描述
我目前正在编写一个面向Java字节码的玩具编译器。
I'm currently writing a toy compiler targeting Java bytecode in the translation.
我想知道是否有某种目录,可以在写入.class文件之前在发出的字节码中进行的各种简单窥视孔优化。我实际上知道有一些库有这个功能,但我想自己实现。
I would like to know if there is some kind of catalog, maybe a summary, of various simple peephole optimizations that can be made in the emitted bytecode before writing the .class file. I actually am aware of some libraries that have this functionality, but I'd like to implement that myself.
推荐答案
的Proguard? http://proguard.sourceforge.net/
You are aware of Proguard? http://proguard.sourceforge.net/
这是一个伟大的字节码优化器,它实现了很多优化。有关列表,请参阅常见问题解答: http://proguard.sourceforge.net/FAQ.html
This is a great bytecode optimizer which implements a lot of optimizations. See the FAQ for a list: http://proguard.sourceforge.net/FAQ.html
- 评估常数表达式。
- 删除不必要的字段访问和方法
调用。 / li>
- 删除不必要的分支。
- 删除不必要的比较和
instanceof测试。 - 删除未使用的代码
。 - 合并相同的代码块。
- 减少变量分配。
- 删除
只写字段和未使用的方法
参数。 - 内联常数字段,
方法参数和返回值。 - 简短或仅
调用一次。 - 简化尾递归
调用。 - 合并类和接口。
- 尽可能使方法为private,static和
final。 - 在可能的情况下创建类
static和final。 - 替换具有单个
实现的接口。 - 执行超过200
个窥视孔优化,例如
替换... * 2由...<< 1。 - (可选)
删除日志记录代码。
- Evaluate constant expressions.
- Remove unnecessary field accesses and method calls.
- Remove unnecessary branches.
- Remove unnecessary comparisons and instanceof tests.
- Remove unused code blocks.
- Merge identical code blocks.
- Reduce variable allocation.
- Remove write-only fields and unused method parameters.
- Inline constant fields, method parameters, and return values.
- Inline methods that are short or only called once.
- Simplify tail recursion calls.
- Merge classes and interfaces.
- Make methods private, static, and final when possible.
- Make classes static and final when possible.
- Replace interfaces that have single implementations.
- Perform over 200 peephole optimizations, like replacing ...*2 by ...<<1.
- Optionally remove logging code.
请查看源代码以了解如何实现它们。
I'm sure you can further look into the source code to understand how they are implemented.
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