Arthur T. wrote:
Most macros start with an optional label. Rather than tying the
label to the first generated machine instruction, it's convenient to
tie it to a DS 0H. That allows you to easily add extra code at the
beginning and to have multiple expansions (depending on parms
specified) without having multiple label handling.
In open code, people often coded
LABEL EQU *
but, if there was an odd-length constant prior to it, it would not be
halfword aligned, so people started using the DS 0H technique,
instead. (Also, IIRC, the TEST instruction has more information if
you code as DS 0H.)
Of course, with modern HLASM it's preferable to code 'DC 0H' rather than
the 'DS 0H' as required by older assembler implementations.
--
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| Edward E. Jaffe | |
| Mgr, Research & Development | [EMAIL PROTECTED] |
| Phoenix Software International | Tel: (310) 338-0400 x318 |
| 5200 W Century Blvd, Suite 800 | Fax: (310) 338-0801 |
| Los Angeles, CA 90045 | http://www.phoenixsoftware.com |
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