Path: utzoo!censor!geac!jtsv16!uunet!cs.utexas.edu!sun-barr!rutgers!bellcore!att!cbnews!r4
From: r4@cbnews.ATT.COM (richard.r.grady..jr)
Newsgroups: comp.bugs.misc
Subject: Re: Hummm, Altos compiler bug/feature?
Keywords: cc, Altos, 586, Floating point
Message-ID: <8759@cbnews.ATT.COM>
Date: 2 Aug 89 16:05:31 GMT
References: <4874@macom1.UUCP>
Reply-To: r4@cbnews.ATT.COM (richard.r.grady..jr)
Distribution: usa
Organization: AT&T Bell Laboratories
Lines: 45

In article <4874@macom1.UUCP> larry@macom1.UUCP (Larry Taborek) writes:
| Ok guys and gals.
| 
| I have a Altos 586 computer running 3.1a version of Xenix.  In
| using the standard compiler that comes with the development set,
| I found that I can only do mathmatical operations on shorts and
| integers.  Floats, longs and doubles do not work.  Example:
| 
| main()
| {
|    int a;
|    long b;
| 
|    a=0;b=0;
|    a++;
|    printf("a = %d\n",a);
|    a = a + 1;
|    printf("a = %d\n",a);
|    b++;
|    printf("b = %d\n",b);
|    b = b + 1;
|    printf("b = %d\n",b);
| }
| 
| When run returns:
| 
| a = 1
| a = 2
| b = 0
| b = 0
| 
| By the way, by using the sizeof command, I find that shorts and
| integers take 2 bytes, longs and floats take 4 bytes and doubles
| take 8 bytes.

In your example above, you have to tell printf()
that the data argument b is long.
You do this by putting a letter "l" in the format specification:
           printf("b = %ld\n",b);
Otherwise, printf() expects a 2-byte quantity, and it takes the
first two (presumably, higher-order) bytes of the 4-byte long.
These 2 bytes would be 00H, and printf() outputs 0.

-------------------------------------------------------------------
Dick Grady              r_r_grady@att.com          ...!att!mvuxd!r4