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

Indirection
., .EXT, .EXT32, .EXT64, .SG, and .SGX are indirection symbols (see Table 14 (page 41)).
identifier
is the identifier of a definition structure to be made equivalent to 'SG'.
'SG'
denotes a 16-bit system global address.
index
is an INT constant that specifies the offset of the element in previous-ident to which the
equivalenced pointer or variable refers. Specify index only with direct variables. index must
end on a word boundary.
+, -
is the word or byte offset, relative to the base of previous-ident, where the equivalenced
variable is placed. For example, if a and b are declared:
INT a[0:9];
INT b = a+5
then b is placed at a[5].
offset
an equivalent INT values in the range 0 through 63.
structure-layout
a BEGIN-END block that contains declarations for structure items.
Example 136 Equivalenced Definition Structure Declaration
STRUCT def_struct = 'SG'[10];
BEGIN
STRING out;
FIXED up;
REAL in;
END;
Equivalenced Referral Structure
The equivalenced referral structure declaration associates a referral structure with a location relative
to the base address of the system global ('SG') or the extended system global ('SGX') data area.
Indirection
., .EXT, .EXT32, .EXT64, .SG, and .SGX are indirection symbols (see Table 14 (page 41)).
identifier
is the identifier of a referral structure to be made equivalent to 'SG'.
System Global Equivalenced Variable Declarations 195