Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!sdd.hp.com!hplabs!hpda!hpcupt1!bla
From: bla@hpcupt1.cup.hp.com (Brad Ahlf)
Newsgroups: comp.sys.hp
Subject: Re: HP-UX `ld' tricks.
Message-ID: <-286539938@hpcupt1.cup.hp.com>
Date: 14 Nov 90 00:10:27 GMT
References: <1783@kuling.UUCP>
Organization: Hewlett Packard, Cupertino
Lines: 33

> I am trying to speed up my linking and have played around with
> the HP-UX 7.0 `ld' options "-X" and "-A". 

For very large programs, you might have better luck speeding up your
links using the '-r' option to accomplish 'prelinks' with 'ld'.  This
could result in a lot less work for the linker to do when rebuilding
very large executables.

You could create a makefile setup for your very large program that uses
the '-r' 'prelinks' of thousands of .o files into handfuls of .o files.
Each 'prelink' merges some hundreds of .o files into a single .o target
file and this work is not repeated in the 'final link' of the few .o files.

Then, a change to a single source file would require a recompile of file.c,
a -r link of file.o into merge1.o and a final link of the few merge*.o files.
In this way, only the hundred or so files which make up merge1.o are again
prelinked, and the other multiple thousands of files are already prelinked,
potentially saving the linker a lot of work.

This method was found, on older releases of HP-UX for huge executable files,
to save significant amounts of link time.  This method could probably save
some link time on just about any vendors' UN*X platform.

Of course, your mileage may vary.  Try it out and see for yourself.
And let us know your results too.

> Bo

Brad Ahlf
bla@hpda.hp.com
This response does not represent the official position of, or statement by,
the Hewlett-Packard Company.  The above data is provided for informational
purposes only.  It is supplied without warranty of any kind.