Reference Guide

46 Chapter 3

HP-UX Architecture Conventions

Location Counters

Just as spaces can be divided into subspaces, subspaces can be further

divided by using location counters. You can use up to four location

counters in each subspace, and the Assembler ﬁlls a separate area for

each location counter. When the assembly is complete, the subspace is

formed by concatenating each of these areas. All references relative to a

location counter are relocated so that they are relative to the complete

subspace.

Unlike subspaces, however, the use of location counters is completely

local to the Assembler. Once the subspace is formed at the end of the

assembly, the distinction among the individual areas built by location

counters disappears. No further reordering or grouping related to

location counters is performed by the linker.

This facility allows you to assemble related data into disjoint pieces of a

subspace, while keeping the source code in a convenient order.

The .LOCCT directive is used to switch from one location counter to

another. The Assembler automatically remembers the previous value of

each location counter within each subspace. When the .SUBSPA directive

is used to switch subspaces, the Assembler automatically begins using

the location counter that was last in effect in the new subspace.