maximum value in S9(09) COMP

saagu · New User Joined: 15 May 2008 Posts: 41 Location: Chennai

Hi,

What is the maximum value that can be fit in "ws-var1 S9(09) COMP".

Value 2145555555 (10 digits) is also able to fit in above variable. Is maximum value for s9(9) is not '999999999'???

Plz let me know on this.

Regards,
Saagu

dbzTHEdinosauer · Posted: Fri Apr 10, 2009 3:59 pm

Saagu,

one of the things you will have to learn is how to look-up such questions in the documentation.

to start with, COBOL (why post this in the JCL forum?)

does not really matter what release of cobol, data definitions have been rather consistent.

top of the page, manuals button.

might as well read about numerics in general as well as binary and you will learn why s9(9) COMP is not 999999999.

Gnanas N · Posted: Fri Apr 10, 2009 4:01 pm

+2147483647

Bill O'Boyle · Posted: Fri Apr 10, 2009 4:07 pm

Depending on the compile option TRUNC, the maximum 'signed' value is 2147483647, because this is represented internally as a binary fullword (X'7FFFFFFF'). An unsigned maximum value would be 4294967295 (X'FFFFFFFF').

IIRC, TRUNC(OPT) limits the maximum (in your example) to 999999999, because truncation is based upon the picture clause.

TRUNC(BIN) always allows the maximum value. The other TRUNC option (STD) is similar to BIN, but not quite the same.

However, if your compiler supports COMP-5 (Native Binary), then you should use this as the TRUNC option has no effect.

Fullwords occupy 4-Bytes.

Regards,

dbzTHEdinosauer · Posted: Fri Apr 10, 2009 4:10 pm

Gnanas N.,

The OP has the answer to one of his questions.
how about the other one?
you have saved him some research and any potential exposure to any other knowledge.

But, then again, I may be too harsh.

This is probably the only thing that he does not understand.

saagu · New User Joined: 15 May 2008 Posts: 41 Location: Chennai

Thanks Gnanas and O'Boyle for your reply.

Regards,
Saagu

Gnanas N · Posted: Fri Apr 10, 2009 4:17 pm

Hi dbzTHEdinosauer,

Bill O'Boyle · Posted: Fri Apr 10, 2009 4:50 pm

I agree that the manual should be the initial source of information and I won't dispute this.

In the case of the TRUNC option and how it deals with binary data, it can be rather "dicey" for newbies and perhaps, a basic overview as to how COBOL interacts with the TRUNC option was warranted.

TRUNC is probably the most confusing and convoluted option in IBM's list of COBOL compiler options. It's been around since OS/VS COBOL (perhaps, even earlier) and it's gone through many different definitions of usage over the years, that someone could write a thesis on it.

Regards,

dbzTHEdinosauer · Posted: Fri Apr 10, 2009 5:50 pm

Bill,

I will be the last to complain of your posts.

I took issue with just providing a value without providing the type of info that you gave.

also, as I was composing my little ditty, you posted first.

Bill O'Boyle · Posted: Fri Apr 10, 2009 6:32 pm

Dick said -

saurabh39 · Posted: Sat Aug 07, 2010 12:40 am

Hi,

I was going through the TRUNC example given in the manual.
For the first example, when I was working using binary, i was able to get the answer as -7621.

And when I tried to reach the same result using, hex, i understood it will be E23B, but how E23B will represent -7621, i couldn't find out the answer.

Please help.

I am talking about the example given in

link -

Regards,
Tushar

Robert Sample · Posted: Sat Aug 07, 2010 12:57 am

Hex E = binary 1110, flip the bits to get 0001
Hex 2 = binary 0010, flip the bits to get 1101
Hex 3 = binary 0011, flip the bits to get 1100
Hex B = binary 1011, flip the bits to get 0100 plus 1 gives 0101

1DC5 converted from hex is 7621. Since the bits were flipped, the number is -7621.

saurabh39 · Posted: Sat Aug 07, 2010 10:01 pm

@Robert - Thanks again.

I understood, that the Complement of the truncated value should be found, to get the correct value. and even link says & i quote

Robert Sample · Posted: Sat Aug 07, 2010 11:49 pm

You are misunderstanding the text and its application. The sign bit of a COMP variable is merely the first bit. When the truncated (half-word) move is done, and the moved result has the first bit turned on, the value is negative -- there' is nothing for COBOL to "know" since this is inherent in the way COMP variables are defined and work.

If you try the TRUNC(BIN) example from the text with 94779 instead of 123451, the resulting value will be positive (I haven't tested with the compiler but the value should be 29243).