|您可以在Wikipedia上了解到此条目的英文信息 LLVM Thanks, Wikipedia.|
LLVM（Low Level Virtual Machine）底层虚拟机，是一个开源(BSD)编译器的基础设施，使用C++编写。它是为了任意一种编程语言写成的程序，利用虚拟技术，创造出编译时，链结时，运行时以及“闲置时”的最佳化。它最早是以 C/C++为处理对象，目前它支持了包括Objective-C, Fortran, Ada, Haskell, Java bytecode, Python, Ruby, ActionScript, GLSL以及其他语言。
- 因不满社区变化，LLVM 资深开发者发长邮件宣布退出 (2018.05)
LLVM采用University of Illinois/NCSA Open Source License, or UIUC 许可证，基于MIT/X11 license and the 3-clause BSD license，兼容GPL。
The LLVM compiler system for C and C++ includes the following:
- Front-ends for C, C++, Objective-C, Fortran, etc based on the GCC 4.2 parsers. They support the ANSI-standard C and C++ languages to the same degree that GCC supports them. Additionally, many GCC extensions are supported.
- A stable implementation of the LLVM instruction set, which serves as both the online and offline code representation, together with assembly (ASCII) and bytecode (binary) readers and writers, and a verifier.
- A powerful pass-management system that automatically sequences passes (including analysis, transformation, and code-generation passes) based on their dependences, and pipelines them for efficiency.
- A wide range of global scalar optimizations.
- A link-time interprocedural optimization framework with a rich set of analyses and transformations, including sophisticated whole-program pointer analysis, call graph construction, and support for profile-guided optimizations.
- An easily retargettable code generator, which currently supports X86, X86-64, PowerPC, PowerPC-64, ARM, Thumb, SPARC, Alpha, and IA-64.
- A Just-In-Time (JIT) code generation system, which currently supports X86, X86-64, PowerPC and PowerPC-64.
- Support for generating DWARF debugging information.
- A C back-end useful for testing and for generating native code on targets other than the ones listed above.
- A profiling system similar to gprof.
- A test framework with a number of benchmark codes and applications.
- APIs and debugging tools to simplify rapid development of LLVM components.
port search llvm sudo port install llvm-3.3