HP-UX 11i Version 1.6 Release Notes

Programming

Link Editor (ld)

Chapter 7

Link Editor (ld)

The Link Editor, ld (1), takes one or more object files or libraries as input and combines

them to produce a single (usually executable) file.

Summary of Change

New functionality introduced to HP-UX 11i v1.6 ld includes:

• Procedure splitting

• Merging shared library segments

• Filtered Library

• Large section table support

• +instrumenter option

• +O selective percent option

The -I option is also changed to use caliper as default instrumenter.

Details of Change

• Procedure splitting (option: +[no]procsplitclean, +vtype procsplitclean)

Procedure splitting enables splitting of the text section into a hot section (.text) and

a cold section (.text.cold) depends on profile information. This creates better locality

and i-cache performance for the hot section code. Linker dumps verbose trace of

procedure splitting using +vtype procsplitclean option.

• Merging shared library segments (option: +mergeseg)

Executable build with the +mergeseg causes the dynamic loader to merge all the

data segments of the shared libraries into one block during startup. The data

segments of the dynamically loaded libraries is also merged with the data segments

of dependent libraries. This increases run-time performance by allowing the kernel

to use larger size page table entries.

• Filtered library (option: +filter shared_library_path)

Filtered library implementation is designed to reduce the amount of data space used

by large shared libraries. It enables large shared libraries to be broken down into

one “filter” (using +filter option) and several “implementation” (regular) libraries.

User links with the filter library, which contains references to all of the symbols of

the implementation libraries. During runtime, only the implementation libraries

that are used are loaded into data space. This functionality decreases the amount of

data space needed for a process if the implementation libraries are partition

correctly.

• Large section table support (no option, automatic)