C语言各类型在x86与x64环境下的长度

最新推荐文章于 2023-03-28 11:05:50 发布

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#c语言 #数据类型 #x86 #x64 #长度

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本文探讨了C语言中的各种基本数据类型在x86和x64架构下的长度差异，包括int、long、char等类型的字节大小，分析了不同平台下编译器如何处理这些数据类型，帮助读者理解跨平台编程时需要注意的细节。

struct T {
    char a;
    int b;
    char c;
};

struct E {
};

// Linux 平台 (基于 CentOS6.5)
printf("%d\n", sizeof(struct T));     //x86 12  x64 12
printf("%d\n", sizeof(struct E));     //x86 0   x64 0
printf("%d\n", sizeof(char));         //x86 1   x64 1   
printf("%d\n", sizeof(short int));    //x86 2   x64 2   
printf("%d\n", sizeof(int));          //x86 4   x64 4   
printf("%d\n", sizeof(long));         //x86 4   x64 8   
printf("%d\n", sizeof(long long));    //x86 8   x64 8   
printf("%d\n", sizeof(float));        //x86 4   x64 4   
printf("%d\n", sizeof(double));       //x86 8   x64 8   
printf("%d\n", sizeof(long double));  //x86 12  x64 16  
printf("%d\n", sizeof(void));         //x86 1   x64 1   
printf("%d\n", sizeof(void*));        //x86 4   x64 8   
printf("%d\n", sizeof(size_t));       //x86 4   x64 8   

// Windows 平台 (基于 VS2013 Win10)
printf("%d\n", sizeof(struct T));     //x86 12  x64 12
printf("%d\n", sizeof(struct E));     //x86 1   x64 1
printf("%d\n", sizeof(short int));    //x86 2   x64 2
printf("%d\n", sizeof(int));          //x86 4   x64 4
printf("%d\n", sizeof(long));         //x86 4   x64 4
printf("%d\n", sizeof(long long));    //x86 8   x64 8
printf("%d\n", sizeof(float));        //x86 4   x64 4
printf("%d\n", sizeof(double));       //x86 8   x64 8
printf("%d\n", sizeof(long double));  //x86 8   x64 8
//printf("%d\n", sizeof(void));       //error C2070
printf("%d\n", sizeof(void*));        //x86 4   x64 8
printf("%d\n", sizeof(size_t));       //x86 4   x64 8

类型	Linux x86	Linux x64	Win x86	Win x64
struct T	12	12	12	12
struct E	0	0	1	1
char	1	1	1	1
short int	2	2	2	2
int	4	4	4	4
long	4	8	4	4
long long	8	8	8	8
float	4	4	4	4
double	8	8	8	8
long double	12	16	8	8
void	1	1	-	-
void*	4	8	4	8
size_t	4	8	4	8

类型	format
char	%c
signed char	%c (or %hhi for numerical output)
unsigned char	%c (or %hhu for numerical output)
short short int signed short signed short int	%hi
unsigned short unsigned short int	%hu
int signed signed int	%i or %d
unsigned unsigned int	%u
long long int signed long signed long int	%li or %ld
unsigned long unsigned long int	%lu
long long long long int signed long long signed long long int	%lli or %lld
unsigned long long unsigned long long int	%llu
float	%f (promoted automatically to double for printf())
double	%f (%F)(%lf (%lF) for scanf()) %g %G %e %E
long double	%Lf %LF %Lg %LG %Le %LE