1 long long acc; 2 addhi(short a)3addhi (short a) 4 { 5 acc += (long long) a << 32; 6 } 7 subhi(short a)8subhi (short a) 9 { 10 acc -= (long long) a << 32; 11 } 12 main()13main () 14 { 15 acc = 0xffff00000000ll; 16 addhi (1); 17 if (acc != 0x1000000000000ll) 18 abort (); 19 subhi (1); 20 if (acc != 0xffff00000000ll) 21 abort (); 22 exit (0); 23 } 24