HLASM Language Reference

DC Instruction
assembled into the constant. Symbols used in subfield 1 need not be previously
defined. This does not apply to literals.
The duplication factor can be specified by an unsigned decimal self-defining term or
by an absolute expression enclosed in parentheses.
The factor must have a positive value or be equal to zero.
Notes:
1. A duplication factor of zero is permitted, except for literals, with the following
results:
No value is assembled.
Alignment is forced according to the type of constant specified, if no length
attribute is present (see “Alignment of Constants” on page 129).
The length attribute of the symbol naming the constant is established
according to the implicitly or explicitly specified length.
When the duplication factor is zero, the nominal value may be omitted. The
alignment is forced, even if the NOALIGN option is specified.
When the duplication factor is zero for a literal, the assembler issues message
ASMA67S Illegal duplication factor.
2. If duplication is specified for an address constant whose nominal value contains
a location counter reference, the value of the location counter reference is
incremented by the length of the constant before each duplication is done (see
| “Address Constants—A and Y” on page 153). If the duplication factor is zero,
| the value of the location counter reference is not incremented by the length of
| each constant that would have been generated for a non-zero duplication
| factor. Thus, in each of the following two statements, the first generates an
| ASMA072E error message for "Data item too large", but the second does not:
| A DC Y(,32768-(-A))
| B DC Y(,32768-(-B))
However, if duplication is specified for an address-type literal constant
containing a location counter reference, the value of the location counter
reference is not incremented by the length of the literal before each duplication
is done. The value of the location counter reference is the location of the first
byte of the literal in the literal pool, and is the same for each duplication.
The location counter value is that of the instruction in which the literal appears
for A-type constants, but for S-type constants it is the location where the literal
actually appears.
3. The maximum value for the duplication factor is 2 24 −1, or X'FFFFFF' bytes. If
the maximum value for the duplication factor is exceeded, the assembler issues
message ASMA67S Illegal duplication factor.
Subfield 2: Type
The syntax for coding the type is shown in the subfield format on page 127.
You must specify the type subfield. From the type specification, the assembler
determines how to interpret the constant and translate it into the correct format.
The type is specified by a single-letter code as shown in Figure 35, the type
extension as shown in Figure 36.
Chapter 5. Assembler Instruction Statements 133