C ++全局变量的性能 [英] C++ performance of global variables

问题描述

澄清：我知道全局变量有多坏，何时不使用它们）

For clarification: I know how evil globals are and when not to use them :)

• 访问/在编译的C ++程序中设置全局变量和局部变量？

推荐答案

完全取决于您的机器架构。全局变量通过单个已知地址访问，而局部变量通常通过索引地址寄存器访问。两者之间的差异很大的机会是非常遥远的，但如果你认为这很重要，你应该为你的目标架构写一个测试，并测量差异。

That would depend entirely on your machine architecture. Global variables are accessed via a single known address, whereas local variables are typically accessed by indexing off an address register. The chances of the difference between the two being significant is extremely remote, but if you think it will be important, you should write a test for your target architecture and measure the difference.

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