int main() {
signed short x=-1;
unsigned short y;
signed short z;
z = sizeof(x);
y = sizeof(x);
if ( x < z ) printf("aaa \n");
else printf("bbb \n");
if ( x < y ) printf("aaa \n");
else printf("bbb \n");
if ( x < sizeof(x) ) printf("aaa \n");
else printf("bbb \n");

return 0;
}
./a.out
aaa
aaa
bbb

>>793 無論、釣りですが、説明がつきません。