pTAL Reference Manual (G06.24+, H06.09+, J06.03+)

Indirection
., .EXT, .EXT32, .EXT64, .SG, and .SGX are indirection symbols (see Table 14 (page 41)).
NOTE: Indirection symbols, .EXT32 and .EXT64 are available in the 64-bit addressing
functionality added to the EpTAL compiler starting with SPR T0561H01^AAP. For more
information, see Appendix E, “64-bit Addressing Functionality” (page 531).
identifier
is the identifier of the simple pointer.
REFALIGNED
specifies the base alignment of the structures that the structure pointer will reference.
2
references a structure that might not be well-aligned.
8
indicates that the base of the structure and the fields in the structure are well aligned in memory
Example 90 Simple Pointers Within a Structure
STRUCT my_struct;
BEGIN
FIXED . std_pointer; ! Standard simple pointer
STRING .EXT ext_pointer; ! Extended 32-bit simple pointer
STRING .EXT32 ext32_pointer ! Extended 32-bit simple pointer
INT .EXT64 ext64_pointer ! Extended 64-bit simple pointer
END;
Topics:
• Using Simple Pointers (page 149)
• Assigning Addresses to Pointers in Structures (page 150)
Using Simple Pointers
The data type determines the size of data a simple pointer can access at a time.
Table 46 Data Accessed by Simple Pointers
Accessed DataData Type
ByteSTRING
WordINT
DoublewordINT(32)
DoublewordREAL
QuadruplewordREAL(64)
QuadruplewordFIXED
The addressing mode and data type determine the kind of address the simple pointer can contain.
Table 47 Addresses in Simple Pointers
Kind of AddressData TypeAddressing Mode
16-bit byte addressSTRINGStandard
16-bit word addressAny except STRINGStandard
32-bit or 64-bit
*
byte address, normally in the automatic
extended data segment
STRINGExtended
Declaring Simple Pointers in Structures 149