22 lines
334 B
C
22 lines
334 B
C
|
#include <stdio.h>
|
||
|
|
#include <inttypes.h>
|
||
|
|
|
||
|
|
void changeSign(float *f) {
|
||
|
|
union {
|
||
|
|
float f;
|
||
|
|
uint32_t u;
|
||
|
|
} tmp;
|
||
|
|
tmp.f = *f;
|
||
|
|
tmp.u = tmp.u ^ 0x80000000;//1000 0000 0000 0000 0000 0000 0000 0000
|
||
|
|
*f = tmp.f;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
int main(void)
|
||
|
|
{
|
||
|
|
float f = 4.0;
|
||
|
|
changeSign(&f);
|
||
|
|
printf("%f\n",f);
|
||
|
|
return 0;
|
||
|
|
}
|