Replacing ld with gold - any experience?

At the moment it is compiling bigger projects on Ubuntu 10.04. Here you can install and integrate it easily with the binutils-gold package (if you remove that package, you get your old ld). Gcc will automatically use gold then.

Some experiences:

• gold doesn't search in /usr/local/lib
• gold doesn't assume libs like pthread or rt, had to add them by hand
• it is faster and needs less memory (the later is important on big C++ projects with a lot of boost etc.)

What does not work: It cannot compile kernel stuff and therefore no kernel modules. Ubuntu does this automatically via DKMS if it updates proprietary drivers like fglrx. This fails with ld-gold (you have to remove gold, restart DKMS, reinstall ld-gold.

As it took me a little while to find out how to selectively use gold (i.e. not system-wide using a symlink), I'll post the solution here. It's based on http://code.google.com/p/chromium/wiki/LinuxFasterBuilds#Linking_using_gold .

1. Make a directory where you can put a gold glue script. I am using ~/bin/gold/.

2. Put the following glue script there and name it ~/bin/gold/ld:

   #!/bin/bashgold "$@"

   Obviously, make it executable, chmod a+x ~/bin/gold/ld.

3. Change your calls to gcc to gcc -B$HOME/bin/gold which makes gcc look in the given directory for helper programs like ld and thus uses the glue script instead of the system-default ld.

Can gcc/g++ directly call gold.?

Just to complement the answers: there is a gcc's option -fuse-ld=gold (see gcc doc). Though, AFAIK, it is possible to configure gcc during the build in a way that the option will not have any effect.