LLVM

The Low-Level Virtual Machine (LLVM) is a compiler infrastructure, a collection of libraries and tools that make it easy to build compilers, optimizers, Just-In-Time code generators, and many other compiler-related programs.

LLVM uses a single, language-independent virtual instruction set both as an offline code representation (to communicate code between compiler phases and to run-time systems) and as the compiler internal representation (to analyze and transform programs). This persistent code representation allows a common set of sophisticated compiler techniques to be applied at compile-time, link-time, install-time, run-time, or "idle-time" (between program runs).

The strengths of the LLVM infrastructure are its extremely simple design (which makes it easy to understand and use), source-language independence, powerful mid-level optimizer, automated compiler debugging support, extensibility, and its stability and reliability. LLVM is currently being used to host a wide variety of academic research projects and commercial projects. LLVM includes C and C++ front-ends (based on GCC 4.0.1), a front-end for a Forth-like language (Stacker), a young scheme front-end, and Java support is in development. LLVM can generate code for X86, SparcV9, PowerPC, or it can produce C code.

The clang project is an effort to build a set of new 'LLVM native' front-end technologies for the LLVM optimizer and code generator.

LLVM 2.8

Price Free to download Size 8.7MB License University of Illinois Open Source License Developer LLVM Developer Group Website llvm.org System Requirements Support Sites: Documentation, FAQ, Wiki, Mailing Lists Selected Reviews:

Features include:

• 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
• Includes an aggressive optimizer, including scalar, interprocedural, profile-driven, and some simple loop optimizations
• 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, CellSPU, PIC16 MIPS, MSP430, SystemZ, and XCore
• 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
• Supports a life-long compilation model, including link-time, install-time, run-time, and offline optimization

Last Updated Saturday, April 09 2011 @ 08:41 AM EDT