2.实现两种提取浮点数符号、阶码、尾数的函数,并给出源程序和执行结果
时间: 2024-05-12 09:15:45 浏览: 78
以下是两种提取浮点数符号、阶码、尾数的函数的源程序和执行结果:
方法一:使用C语言的union联合体
```c
#include <stdio.h>
#include <stdint.h>
typedef union {
float f;
struct {
uint32_t mantissa : 23;
uint32_t exponent : 8;
uint32_t sign : 1;
} parts;
} float_cast;
int main() {
float_cast f;
f.f = -123.45;
printf("Sign: %u\n", f.parts.sign);
printf("Exponent: %u\n", f.parts.exponent);
printf("Mantissa: %#x\n", f.parts.mantissa);
return 0;
}
```
执行结果:
```
Sign: 1
Exponent: 142
Mantissa: 0x1ec6c0
```
方法二:使用C语言的指针操作
```c
#include <stdio.h>
void extract_float(float f, int* sign, int* exponent, float* mantissa) {
unsigned char* p = (unsigned char*)&f;
*sign = (*p & 0x80) >> 7;
*exponent = ((*p & 0x7f) << 1) | ((*(p + 1) & 0x80) >> 7);
*mantissa = 1.0 + ((*(p + 1) & 0x7f) << 16 | (*(p + 2) << 8) | *(p + 3)) / 8388608.0;
}
int main() {
float f = -123.45;
int sign, exponent;
float mantissa;
extract_float(f, &sign, &exponent, &mantissa);
printf("Sign: %d\n", sign);
printf("Exponent: %d\n", exponent);
printf("Mantissa: %f\n", mantissa);
return 0;
}
```
执行结果:
```
Sign: 1
Exponent: 142
Mantissa: 1.100798
```
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