编译的基本思想实际上非常简单。原则上，递归下降解析器可以以I/O限制的速度运行。代码生成基本上是一个非常简单的过程。符号表和基本类型系统并不需要大量的计算。

然而，降低编译器的速度并不难。

如果存在一个预处理器阶段，其中包含多级包含指令、宏定义和条件编译，尽管这些东西很有用，但加载它并不难。(举个例子，我想到了Windows和MFC头文件。)这就是为什么预编译头文件是必要的。

在优化生成的代码方面，可以向该阶段添加多少处理是没有限制的。

围棋的设计就是要快，这一点已经体现出来了。

Dependency Management: no header file, you just need to look at the packages that are directly imported (no need to worry about what they import) thus you have linear dependencies. Grammar: the grammar of the language is simple, thus easily parsed. Although the number of features is reduced, thus the compiler code itself is tight (few paths). No overload allowed: you see a symbol, you know which method it refers to. It's trivially possible to compile Go in parallel because each package can be compiled independently.

请注意，Go并不是唯一具有这些特性的语言(模块是现代语言的标准)，但它们做得很好。

摘自Alan Donovan和Brian Kernighan所著的《the Go Programming Language》一书:

Go compilation is notably faster than most other compiled languages, even when building from scratch. There are three main reasons for the compiler’s speed. First, all imports must be explicitly listed at the beginning of each source file, so the compiler does not have to read and process an entire file to determine its dependencies. Second, the dependencies of a package form a directed acyclic graph, and because there are no cycles, packages can be compiled separately and perhaps in parallel. Finally, the object file for a compiled Go package records export information not just for the package itself, but for its dependencies too. When compiling a package, the compiler must read one object file for each import but need not look beyond these files.

Go编译器比大多数C/ c++编译器快得多的原因有很多:

Top reason: Most C/C++ compilers exhibit exceptionally bad designs (from compilation speed perspective). Also, from compilation speed perspective, some parts of the C/C++ ecosystem (such as editors in which programmers are writing their code) aren't designed with speed-of-compilation in mind. Top reason: Fast compilation speed was a conscious choice in the Go compiler and also in the Go language The Go compiler has a simpler optimizer than C/C++ compilers Unlike C++, Go has no templates and no inline functions. This means that Go doesn't need to perform any template or function instantiation. The Go compiler generates low-level assembly code sooner and the optimizer works on the assembly code, while in a typical C/C++ compiler the optimization passes work on an internal representation of the original source code. The extra overhead in the C/C++ compiler comes from the fact that the internal representation needs to be generated. Final linking (5l/6l/8l) of a Go program can be slower than linking a C/C++ program, because the Go compiler is going through all of the used assembly code and maybe it is also doing other extra actions that C/C++ linkers aren't doing Some C/C++ compilers (GCC) generate instructions in text form (to be passed to the assembler), while the Go compiler generates instructions in binary form. Extra work (but not much) needs to be done in order to transform the text into binary. The Go compiler targets only a small number of CPU architectures, while the GCC compiler targets a large number of CPUs Compilers which were designed with the goal of high compilation speed, such as Jikes, are fast. On a 2GHz CPU, Jikes can compile 20000+ lines of Java code per second (and the incremental mode of compilation is even more efficient).

依赖性分析。

Go FAQ通常包含以下句子:

围棋为软件提供了一个模型 产生依赖性的构造 分析简单，避免了很多 c风格include文件的开销和 库。

虽然这个短语不再出现在FAQ中，但这个主题在谷歌的Go谈话中进行了详细阐述，该谈话比较了C/ c++和Go的依赖分析方法。

这是快速编译的主要原因。这是设计出来的。

我认为不是Go编译器快，而是其他编译器慢。

C和c++编译器必须解析大量的头文件——例如，编译c++“hello world”需要编译18k行代码，这几乎是半兆字节的源代码!

$ cpp hello.cpp | wc
  18364   40513  433334

Java和c#编译器在VM中运行，这意味着在它们编译任何东西之前，操作系统必须加载整个VM，然后必须将它们从字节码编译为本机代码，所有这些都需要一些时间。

编译的速度取决于几个因素。

有些语言被设计为快速编译。例如，Pascal被设计为使用单遍编译器进行编译。

编译器本身也可以优化。例如，Turbo Pascal编译器是用手工优化的汇编器编写的，结合语言设计，可以在286类硬件上运行非常快的编译器。我认为即使是现在，现代的Pascal编译器(例如FreePascal)也比Go编译器快。