From: vbresan AT jagor DOT srce DOT hr (Viktor Bresan)
Newsgroups: comp.os.msdos.djgpp
Subject: What's this? A bug?
Date: 6 Oct 1999 17:10:51 +0200
Organization: Sveucilisni Racunarski CEntar
Lines: 50
Message-ID: <MO8+3UJ05Q5a092yn@jagor.srce.hr>
NNTP-Posting-Host: jagor.srce.hr
X-Trace: bagan.srce.hr 939222682 20432 161.53.2.130 (6 Oct 1999 15:11:22 GMT)
X-Complaints-To: news AT news DOT carnet DOT hr
NNTP-Posting-Date: 6 Oct 1999 15:11:22 GMT
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

Here is the code which counts the number of nonzero bits in int value.
It works fine until you enter negativ value, e.g. when i enter value -1
it counts 32 nonzero bits (although we all know that int has only 16 bits)!?
The same code compiled under the BC++ 3.1 acts normal (under 16 bits counted
for each negative value).

Am i doing something wrong? What happends here?
Thanx!

--------------------------------- cut - cut ---------------------------------
#include <conio.h>
#include <stdio.h>


char CntBits(int val)
 { char ret_val;
   int maska;

   ret_val = 0;
   maska = 1;
   while(maska)
     {
       if(val & maska)
           ret_val++;

       maska <<= 1;
     }

   return (ret_val);
 }

int main(/*int argc, char *argv[]*/)
 { char CntBits(int);
   int val;

   clrscr();
   printf("Enter int value: ");
   scanf("%i",&val);

   printf("%i nonzero bit(s)!",CntBits(val));

   return (0);
 }

----------------------------------- cut - cut -------------------------------


-- 
Viktor Bresan, student of electronics at FESB Split, Croatia
http://public.srce.hr/~vbresan/