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

! standard indirect variable
END;
Declaring Nonstructure Equivalenced Variables
Nonstructure equivalenced declarations include simple variables, pointers, and arrays.
VOLATILE
specifies that the value of this variable must be maintained in memory, not in a register. 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.
type
If referral is present, must be STRING or INT; otherwise, type is any data type except
UNSIGNED.
identifier
is the identifier of the equivalenced variable to be made equivalent to previous-identifier.
referral
is the identifier of a previously declared structure, structure layout, or structure pointer.
previous-identifier
the identifier of a previously-declared variable, direct array element, pointer, structure, structure
pointer, or equivalenced variable.
index
is an INT constant that specifies an element offset from previous-identifier 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-identifier, 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].
180 Equivalenced Variables