16 位整数 vs 32 位整数 vs 64 位整数 [英] 16 bit Int vs 32 bit Int vs 64 bit Int
问题描述
因为我从未接受过计算机科学的正规"教育(我在高中)，所以我一直想知道这个问题，所以请原谅我对这个主题的无知.
I've been wondering this for a long time since I've never had "formal" education on computer science (I'm in highschool), so please excuse my ignorance on the subject.
在支持标题中列出的三种整数类型的平台上，哪个更好，为什么?(我知道每种类型的 int 在内存中都有不同的长度，但我不确定这意味着什么或它如何影响性能，或者从开发人员的角度来看，哪个比另一个更有优势).
On a platform that supports the three types of integers listed in the title, which one's better and why? (I know that every kind of int has a different length in memory, but I'm not sure what that means or how it affects performance or, from a developer's view point, which one has more advantages over the other).
预先感谢您的帮助.
推荐答案
更好"是一个主观术语，但某些整数在某些平台上的性能更高.
"Better" is a subjective term, but some integers are more performant on certain platforms.
例如，在 32 位计算机(由 32 位平台和 Win32 等术语引用)中，CPU 被优化为一次处理 32 位值，而 32 指的是CPU 可以在一个周期内消耗或产生.(这是一个非常简单的解释，但它传达了总体思路).
For example, in a 32-bit computer (referenced by terms like 32-bit platform and Win32) the CPU is optimized to handle a 32-bit value at a time, and the 32 refers to the number of bits that the CPU can consume or produce in a single cycle. (This is a really simplistic explanation, but it gets the general idea across).
在 64 位计算机中(最新的 AMD 和 Intel 处理器属于此类)，CPU 被优化为一次处理 64 位值.
In a 64-bit computer (most recent AMD and Intel processors fall into this category), the CPU is optimized to handle 64-bit values at a time.
因此，在 32 位平台上，加载到 32 位地址中的 16 位整数需要将 16 位清零，以便 CPU 可以对其进行操作；一个 32 位整数将立即可用而无需任何更改，并且一个 64 位整数需要在两个或多个 CPU 周期内操作(一次用于低 32 位，然后再次用于高 32 位).
So, on a 32-bit platform, a 16-bit integer loaded into a 32-bit address would need to have 16 bits zeroed out so that the CPU could operate on it; a 32-bit integer would be immediately usable without any alteration, and a 64-bit integer would need to be operated on in two or more CPU cycles (once for the low 32-bits, and then again for the high 32-bits).
相反，在 64 位平台上，16 位整数需要将 48 位清零，32 位整数需要将 32 位清零，并且可以立即对 64 位整数进行运算.
Conversely, on a 64-bit platform, 16-bit integers would need to have 48 bits zeroed, 32-bit integers would need to have 32 bits zeroed, and 64-bit integers could be operated on immediately.
每个平台和 CPU 都有一个本机"位(例如 32 或 64)，这通常会限制该 CPU 可以访问的其他一些资源(例如，3GB/4GB 内存限制为 32-位处理器).80386 处理器系列(以及后来的 x86)处理器使 32 位成为常态，但现在像 AMD 和英特尔这样的公司目前正在使 64 位成为常态.
Each platform and CPU has a 'native' bit-ness (like 32 or 64), and this usually limits some of the other resources that can be accessed by that CPU (for example, the 3GB/4GB memory limitation of 32-bit processors). The 80386 processor family (and later x86) processors made 32-bit the norm, but now companies like AMD and then Intel are currently making 64-bit the norm.
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