IEEE 754 单精度浮点的SEM表示

#include <iostream>

using namespace std;

typedef union {

float f;

struct {

unsigned int mantissa : 23;

unsigned int exponent : 8;

unsigned int sign : 1;

} parts;

unsigned char hex4;

} ieee754_float;

int main()

{

float value = 0.101101f;

ieee754_float u;

u.f = value;

printf("Sign: %u\n", u.parts.sign);

printf("Exponent: %u\n", u.parts.exponent);

printf("Mantissa: %u\n", u.parts.mantissa);

printf("%#x,%#x,%#x,%#x\n", u.hex3,u.hex2,u.hex1,u.hex0);

unsigned char hex\[\] = { 0x42, 0x3e, 0x60, 0x00 };

u.hex3 = hex0;

u.hex2 = hex1;

u.hex1 = hex2;

u.hex0 = hex3;

printf("float original data: %f\n", u.f);

return 0;

}