pTAL Conversion Guide

Lexical Elements
pTAL Conversion Guide—527302-002
3-3
Address-Base Symbols
All other bit-extract operators can be immediately followed by any binary operator, as in
TAL.
Address-Base Symbols
TAL and pTAL support different address-base symbols:
Both SG and SGX pointers reference data in the system data segment, and both are
16 bits in TNS processes. In native processes, SG pointers are 16 bits and SGX
pointers are 32 bits.
Indirection Symbols
TAL
You can use an indirection symbol to assign a value to the implicit pointer of an indirect
array or indirect structure.
pTAL
You cannot use indirection symbols. To achieve the effect of an implicit pointer, declare
a pointer and assign to it the address of the indirect array or indirect structure, as in
Example 15-7 on page 15-7.
New Reserved Keywords
pTAL supports the following new reserved keywords:
If your program uses any of the preceding reserved keywords as identifiers, you must
change your code to use different identifiers.
Symbol Meaning TAL pTAL
'P' P-register addressing (read-only arrays) Yes Yes
'G' References global user data area Yes No
'L' References local user data area Yes No
'S' References sublocal user data area Yes No
'SG' References system global data area Yes Yes
'SGX' References system global data area No Yes
BADDR FIELDALIGN REFALIGNED SGXWADDR
CBADDR PROCADDR SGBADDR VOLATILE
CWADDR PROCPTR SGWADDR WADDR
EXTADDR REAL SGXBADDR