LLVM 源码分析（三）ImmutablePass

最新推荐文章于 2024-01-08 12:47:20 发布

ychw365

最新推荐文章于 2024-01-08 12:47:20 发布

阅读量1.7k

点赞数 1

分类专栏： llvm

本文链接：https://blog.youkuaiyun.com/ychw365/article/details/8746490

版权

llvm 专栏收录该内容

5 篇文章

订阅专栏

本文深入探讨了LLVM编译框架中的ImmutablePass，这是一个不修改IR的编译阶段优化。通过分析其工作机制，了解如何在LLVM中实现静态分析和优化，为编译器性能提升提供关键洞察。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

//===----------------------------------------------------------------------===//
/// ImmutablePass class - This class is used to provide information that does
/// not need to be run.  This is useful for things like target information and
/// "basic" versions of AnalysisGroups.
///
class ImmutablePass : public ModulePass {
public:
  /// initializePass - This method may be overriden by immutable passes to allow
  /// them to perform various initialization actions they require.  This is
  /// primarily because an ImmutablePass can "require" another ImmutablePass,
  /// and if it does, the overloaded version of initializePass may get access to
  /// these passes with getAnalysis<>.
  ///
  virtual void initializePass();


  virtual ImmutablePass *getAsImmutablePass() { return this; }


  /// ImmutablePasses are never run.
  ///
  bool runOnModule(Module &) { return false; }


  explicit ImmutablePass(char &pid)
  : ModulePass(pid) {}


  // Force out-of-line virtual method.
  virtual ~ImmutablePass();
};

这个类里有现实的使用方式但是这个基本是llvm 本身需求的我们开发过程中很少会使用

MachineModuleInfo.cpp 里面

class MachineModuleInfo : public ImmutablePass