float.c

#include <stdio.h>

union fi
{
	unsigned i;
	float f;
};

int main(void)
{
	union fi fi = { .f = 16777000.0 };
	while(((float)(fi.f += 1.0)) != ((float)(fi.f+1.0)))
	{
		printf("%.1f (%u) + 1.0 = %.1f (%.1lf)\n",fi.f,fi.i,(float) (fi.f+1.0),((double) fi.f)+1.0);
	}
	printf("%.1f (%u) + 1.0 = %.1f (%.1lf)\n",fi.f,fi.i,(float) (fi.f+1.0),((double) fi.f)+1.0);
	fi.i++;
	printf("%.1f (%u) + 1.0 = %.1f (%.1lf)\n",fi.f,fi.i,(float) (fi.f+1.0),((double) fi.f)+1.0);

	printf("16777216.0f %c= 16777217.0f\n",(16777216.0f == 16777217.0f) ? '=' : '!');

	return 0;
}