Re: how to create unsigned hexadecimal initial value

["Leif Svalgaard" <leif@xxxxxxxx>]

From: <rjd@us.ibm.com>

> I think even the more recent examples are easy to explain in terms of the
> definition I gave for H literals.
> CPYNV  NN, -1;
> AND(S) NN,H'0003'; /* Equivalent to AND(S) NN, 3; */
> CVTHC MSG-TEXT(1:4), XX;
> CALLI SHOW-MESSAGE, *, .SHOW-MESSAGE;    <==== shows  0300    wrong
>
> H'0003' represents the value 3 and has length 1 (unlike character
> constants, the leading zeros are not significant).  Based on the
> specification for AND(S), the shorter operand is padded on the right with
> zeros.  So, the expected result of ANDing op1=x'FFFF' with op2=x'03' is
> x'0300'.

In my rewriting of your definition I said:
"The length of an H literal is always 4 bytes".
That does not explain the above behavior. You suggested the asymmetrical
definition that for non-negative literals, leading zero-valued bytes be
dropped
in calculating the length. Although that would explain the behavior, I have
a semantic problem with it, as it leads to integers of length 1 or 3 which
are normally not defined (there is no BIN(1)). I also have a problem with
the value H'00'. Is that a BIN(1) or a BIN(0) value?

Finally, your definition does not explain:

CPYNV  NN, -1;
AND(S) NN,H'0123'; /* gives 2300, WRONG */


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