# 8.4.6 总结

深入了解编译器内联机制之后，我们可以写出更加益于编译器优化的代码。例如我们有一个很复杂的函数：

```go
func ReallyBigFunc() {
    // Part 1: Fast Operations with few statements
    // stmt0
    // stmt1
    result := expr()
    if result {
        return
    }

    // Part 2: Slow operations with many statements
    // stmt4
    // stmt5
    // ...
    // stmt100
}
```

假设该函数使用得极其频繁，而大多数情况下函数都会在第一个 `if` 语句处返回，只有极少数情况下需要执行后面的 Slow Operation. 由于函数的总体复杂度很大，因此编译器不会对其进行内联，所以程序在执行时需要付出很大的调用开销。一个优化的策略是让编译器将 Part 1 的代码进行内联，我们可以将 Part 2 单独提取为一个函数：

```go
func slowOp() {
    // Part 2: Slow operations with many statements
    // stmt4
    // stmt5
    // ...
    // stmt100
}

func ReallyBigFunc() {
    // Part 1: Fast Operations with few statements
    // stmt0
    // stmt1
    result := expr()
    if !result {
        slowOp()
    }
}

func main() {
    ReallyBigFunc()
}
```

这样函数 `ReallyBigFunc()` 的行为不会改变但复杂度降低，对于每个调用函数 `ReallyBigFunc()` 的地方编译器都可以将其内联。例如上面的 `main` 函数最终会是如下样子：

```go
func main() {
    // Part 1: Fast Operations with few statements
    // stmt0
    // stmt1
    result := expr()
    if !result {
        slowOp()
    }
}
```

 这样就极大地避免了原函数的调用开销。


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://gocompiler.shizhz.me/8.-golang-bian-yi-qi-inline/8.4.6-zong-jie.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.