C++ IEEE754 数据生成

#include <iostream>
#include <fstream>
#include<stdio.h>
#include <cmath>

using namespace std;



int main(void)
{
    ofstream fotan("/Users/tantaiyunfei/Documents/ttyfLibrary/C++/actan/cos.txt");

    float pi=3.1415926;

    for(float f=0;f<pi/2;)
    {
        //float m=f;
        float m=cos(f);
        unsigned char *p, ch;
        int i;
        p = (unsigned char *) (&m);


        i = sizeof(m);

        for (i = sizeof(m) - 1; i >= 0; i--) {
            ch = *(p + i);
            int j;
            for(j=0;j<8;j++)
            {
                if( (ch<<j) & 0x80) fotan<<1;
                else fotan<<0;
            }


        }
        f=f+0.0001;
        fotan<<"\n";
    }
    fotan.close();
    return 0;
}