I am sure this code is correct!

Why I use this Code by using float_neg(2), it outputs -2147483646? it should output -2? NAN means not a number, just like a string ?

unsigned float_neg(unsigned uf) {

unsigned res = 0;

unsigned tmp = 0;

2 tmp = uf & 0x7fffffff;

-2 res = uf ^ 0x80000000;

if(tmp > 0x7f800000)

res = uf;

return res;

}