LLVM

В последнее время все чаще и чаще в новостях встречается аббревиатура LLVM, хотя проекту, стоящему за этими буквами уже больше 10 лет. Что же такого особенного в, казалось бы, еще одном компиляторе?

LLVM is an umbrella project that hosts and develops a set of close-knit, low-level toolchain components (assemblers, compilers, debuggers, etc.), which are designed to be compatible with existing tools typically used on UNIX systems. The name "LLVM" was once an acronym, but is now just a brand for the umbrella project. While LLVM provides some unique capabilities and is known for some of its widely used tools (the Clang compiler, a C/C++/Objective-C compiler that provides a number of benefits over the GCC compiler), the main thing that sets LLVM apart from other compilers is its internal architecture.

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The most popular design for a traditional static compiler (like most C compilers) is the three phase design whose major components are the front end, the optimizer, and the back end

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While the benefits of a three-phase design are compelling and well-documented in compiler textbooks, in practice, it is almost never fully realized

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let's dive into LLVM: The most important aspect of its design is the LLVM Intermediate Representation (IR), which is the form it uses to represent code in the compiler. LLVM IR is designed to host mid-level analyses and transformations that you find in the optimizer section of a compiler. It was designed with many specific goals in mind, including supporting lightweight runtime optimizations, cross-function/interprocedural optimizations, whole program analysis, and aggressive restructuring transformations, etc. The most important aspect of it, though, is that it is itself defined as a first class language with well-defined semantics.

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After all, the goal isn't to be perfect, it is to keep getting better over time.

drdobbs.com/architecture-and-design/240001128

Очень хорошо, доступно и внятно написанная статья. Весьма поучительно.