如何指定在C 64位整数 [英] How to specify 64 bit integers in c

问题描述

我试图使用64位整数的C，但我得到的混合信号，它是否是可能的。

I'm trying to use 64 bit integers in C, but am getting mixed signals as to whether it should be possible.

在我执行的printf：

When I execute the printf:

printf("Size of long int:%d\nSize of long long int:%d\n\n",(int)sizeof(long int)(int)sizeof(long long int));

我得到的回应是：

The response I get is:

尺寸：4 长长整型尺寸：8

Size of long int:4 Size of long long int:8

这让我觉得很长的长整型有8个字节= 64位。

This makes me feel that a long long int has 8 bytes = 64 bits.

然而，当我试图声明以下变量：

However, when I try to declare the following variables:

long long int a2 = 0x00004444;
long long int b2 = 0x000044440;
long long int c2 = 0x0000444400;
long long int d2 = 0x00004444000;
long long int e2 = 0x000044440000;
long long int f2 = 0x0000444400004;
long long int g2 = 0x00004444000044;
long long int h2 = 0x000044440000444;
long long int i2 = 0x0000444400004444;

最后的4个变量（F2，G2，H2，I2）给我的错误信息：

The last 4 variables (f2,g2,h2,i2) give me the error message:

警告：整型常量太大长类型

warning: integer constant is too large for ‘long’ type

我得到的时候我替换得到long long int'与'的int64_t'相同的结果。我想'的int64_t'被认可，因为它没有产生任何自己的错误消息。

I get the same result when I replace 'long long int' with 'int64_t'. I assume 'int64_t' was recognized, since it didn't generate any error messages of its own.

所以，看来我的8字节长的长整型真的是一个6字节长的长整型，我不明白我在这里缺少什么。如果它的任何帮助，这里是我的gcc编译器的信息：

So, it appears my 8 byte long long int is really a 6 byte long long int, and I don't understand what I'm missing here. If it's any help, here is the information on my gcc compiler:

me@ubuntu:~$ gcc -v  
Using built-in specs.  
Target: i686-linux-gnu  
Configured with: ../src/configure -v   
--with-pkgversion='Ubuntu/Linaro 4.4.4-14ubuntu5'  
--with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs   
--enable-languages=c,c++,fortran,objc,obj-c++  
--prefix=/usr   
--program-suffix=-4.4   
--enable-shared   
--enable-multiarch   
--enable-linker-build-id   
--with-system-zlib   
--libexecdir=/usr/lib   
--without-included-gettext   
--enable-threads=posix   
--with-gxx-include-dir=/usr/include/c++/4.4   
--libdir=/usr/lib   
--enable-nls   
--with-sysroot=/ -  
-enable-clocale=gnu   
--enable-libstdcxx-debug   
--enable-objc-gc   
--enable-targets=all 
--disable-werror   
--with-arch-32=i686   
--with-tune=generic   
--enable-checking=release   
--build=i686-linux-gnu   
--host=i686-linux-gnu   
--target=i686-linux-gnu  
Thread model: posix  
gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5)   

如果有人知道（或）64位整数如何接触到我，我真的AP preciate任何帮助。谢谢....

If anyone knows how (or if) 64 bit integers are accessible to me, I'd really appreciate any help. Thanks....

推荐答案

使用 stdint.h 整数数据类型的特定大小，也可以使用相应的后缀整数文字常数，例如：

Use stdint.h for specific sizes of integer data types, and also use appropriate suffixes for integer literal constants, e.g.:

#include <stdint.h>

int64_t i2 = 0x0000444400004444LL;

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