TIP - Shrinking Openoffice

[extraketchup]

Howdy all,

I'm sure I'm not the only one to do this, but I wanted to share my experiences just in case.

I'm a fan of the -Os flag for compilation. I don't use it on everything, but I like Linus' approach - use O2 for things like the kernel, and use Os for applications, especially large, bloated apps like Openoffice.

The trick with Openoffice is that it turns off -Os by default. In the ebuild, you'll see that -Os is replaced with -O2. However, it is easy to edit the ebuild and change it so that -Os is the default. You'll have to recreate the digest after this by:

Code: Select all

ebuild openoffice-version.ebuild digest

I've never had a compile error doing this. Why do I do this, do you ask? OpenOffice works fast enough for me (I can't out-type it), but those load times - ouch! Reducing the size means reducing the load times, and the hard drive is a much more noticeable bottleneck than a few missed optimizations for the CPU (in this case).

Does it work? Well, I've never ran tests with a stopwatch, but it sure feels like it loads faster. I also notice that my -Os binary (when I emerge with -b option to create a package for the rest of the lab) is about 40 MB smaller than the standard openoffice-bin package. Now, maybe openoffice-bin includes things that my build doesn't, I don't know. What I do know is my openoffice is about 40 MB smaller, and it FEELS like it is loading much quicker (placebo effect - maybe, maybe not). If it didn't take 1000 years to compile, I'd compile a -Os and a -O2 version and benchmark them. However, that's a bit too painful, so I'll go with the gut and say it loads faster.

Anywho, I thought I'd pass that along. -Os performs a large percentage of the -O2 optimizations, AND reduces file size. It won't always be just as fast as -O2 (sometimes it is), but for big programs like Openoffice, I think you'll find improved load times / reduced bloat outweighs any CPU gains of -O2.

Mike[/code]

[ChrisWhite]

Have you considered contacting the maintainer and finding out why they disabled -Os on this? I'm somewhat curious myself. Generally, flags are 'dumbed down' if they're not -O1 or -O2. -Os is not used very often, so it generally is not taken into consideration. I'd check and see.. maybe search bugzilla and post an ehancement but stating your findings.