指针的大小：制约因素 [英] Size of pointers: Dependent factors

问题描述

我在理解上的指针变量的 C 的大小取决于因素，寻找困难。我查了一些参考，我到现在为止的唯一信息是指针的大小取决于处理器架构。我想知道以下细节

I am finding difficulties in understanding the factors on which the size of pointer variables in C is dependent on. I checked few references, the only information I got until now is pointer size is dependent on the processor architecture.I would like to know the following details

• 请解释更多关于如何在木构建筑的影响指针的大小。


• 在一般情况下，如果指针 x位的然后 0至2 ^（X）-1 号地址位置的应该是我.......我失去而与地址位置的数和内存的实际金额可用的程序轨道。

• Please explain more on how the architecure impacts the pointer size.
• In general, if the pointer is of x bits then 0 to 2^(X)-1 number of address locations should be there.I am losing track while relating the number of address locations and the actual amount of memory available to the program.

推荐答案

一个指针是保存另一个内存位置的地址的变量。

A pointer is a variable that holds the address of another memory location.

现在，持有的内存引用（和最有可能的，所有其它寄存器太）将是32位长度的CPU的寄存器;这基本上什么是32位（寄存器都是32位字长的），因此指针（这是一个内存位置）意味着将一般是32位长（4字节）

Now if you are running on a 32-bit architecture, the CPU's registers that hold memory references(and most likely, all other registers too) will be of 32-bit length; that's basically what's meant by 32-bit(the registers are of 32-bit word length) and hence a pointer(which is a memory location) would usually be 32-bits long(4 bytes)

同样适用于64位CPU，因此在编译为64位CPU的C程序的指针将一般有8个字节长度（64位）

Same applies to 64-bit CPUs, and hence the pointers in a C program compiled for 64-bit CPUs will usually have 8 bytes length(64 bits)

编辑：结果
另请注意，在大多数现代架构你不真正解决您的code物理内存;您运行并解决什么叫做虚拟内存。

Please also note that in most modern architectures you don't really address physical memory with your code; you run and address what's called a Virtual Memory.

其基本概念是，你illude程序，您有充分的地址空间，为你的CPU / OS的组合。

The basic concept is that the CPU/OS combination illude your program that you have the full address space for you.

再次地址空间（该空间可以在存储器地址）长度将依赖于CPU可以多远处理地点和（在一般情况下）将取决于它的字大小。

Again, the address-space(the space you can address in memory) length will depend on how far the CPU can address locations and that (in the general case) would depend on its word-size.

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