pTAL Reference Manual (H06.08+)

Pointers

HP pTAL Reference Manual—523746-006

10-16

Declaring Structure Pointers

The structure pointer declaration associates a previously declared structure with the

memory location to which the structure pointer points. You access data in the

associated structure by referencing the qualified structure pointer identifier.

VOLATILE

specifies that the value of this variable must be maintained in memory, not in a

. Each reference to a VOLATILE data item causes the data item to be read

or written to memory even when code is optimized. Based on the order of reads

and writes in the source code, VOLATILE also causes that precise order of

memory references to be preserved, again, when code is optimized.

Example 10-13. Declaring and Initializing a Simple Pointer, Using $XADR

INT a[0:1]; ! 16-bit word-addressed array

STRING .EXT s := $XADR (a[0]); ! Extended simple pointer

! initialized with

! 32-bit byte address of a[0]

Example 10-14. Declaring and Initializing an Extended Simple Pointer

INT .EXT x[-100:100]; ! Array

INT .EXT x_ptr := @x[-5]; ! Extended simple pointer

! initialized with

! 32-bit byte address of x[-5]

VOLATILE

STRING

INT

( )

identifier referral

.EXT

.SG

.SGX

;

initialization

VST677.vsd