110891     Branch And Case Control Structures  Version: 1.0, June 1987
 
Submitted by: Richard Neitzel
 
Operating System: RSX-11M V4.2  Source Language: MACRO-11  Keywords:
MACRO, Structured Languages/Programming, Tools - Applications
Development
 
Abstract: VAX MACRO users have some nice instructions that are not
available on PDPs.  These include several loop control
instructions and case instructions.  However, these can be
emulated quite nicely or even improved.  The MACROs
contained in the file RICHS.MLB contain MACROs that exactly
emulate the function of the following VAX loop control
instructions:  ACBL AOBLEQ AOBLSS SOBGEQ.
 
The VAX case instructions have been altered to yield more
flexible control structures for word, byte and string
values.
 
The loop control MACROs allow the user to code loops that
use an increasing index, an index that increases or
decreases by more than one and continuation of the loop on
equality.  The case MACROs include two MACROs to set up the
required jump table and selector table, as well as the
actual case MACROs.  The case MACROs are:  CASE CASEB CASEST
for word, byte and string operands respectively.  The number
of cases that may be specified is essentially unlimited.
 
Media (Service Charge Code): One RX01 Diskette (KA)  Format: FILES-11,
600' Magnetic Tape (MA)  Format: FILES-11
 
 
