Why does the control falls into loop?

Asked Nov 12 '11 at 08:49

Active Nov 12 '11 at 08:58

Viewed 99 times

Possible Duplicate:
How does Duff's device work?

I recently came across a question in C++ about the working of a C++ code...

 void send(int*to,int* from, int count)
{
  int n = (count+7)/8;
  switch(count%8){
   case 0: do{*to++=*from++;
   case 7:    *to++=*from++;
   case 6:    *to++=*from++;
   case 5:    *to++=*from++;
   case 4:    *to++=*from++;
   case 3:    *to++=*from++;
   case 2:    *to++=*from++;
   case 1:    *to++=*from++;
      }while(--n>0);
   }
 }

How does this code falls into the loop if the value of count%8 comes to be other than 0 as it does not come across the do statement????

edited May 23 '17 at 12:15

Community

asked Nov 12 '11 at 08:49

bhuwansahni

1,834
1
14
20

2

See: http://stackoverflow.com/questions/514118/how-does-duffs-device-work – Mysticial Nov 12 '11 at 08:51
Also,It is a good practice to not write/emulate such code. – Alok Save Nov 12 '11 at 08:55
@Als: Not necessarily. It's a pretty clean way to "clean up" after an unrolled or manually vectorized loop. – Mysticial Nov 12 '11 at 08:57
@Mysticial: It is sure is an way to terrorize your predecessor who will maintain it further. – Alok Save Nov 12 '11 at 09:14

Why does the control falls into loop?

0 Answers0