On Mon, 2 Jun 2014 23:53:38 +0600 Rashif Ray Rahman <schiv@archlinux.org> wrote:
On 2 June 2014 18:56, Yamakaky <yamakaky@yamaworld.fr> wrote:
I believe when the decision was made it was simply based on the fact that being able to share is worth more for the community than local optimization.
PKGBUILDs and packages from repositories have to be portable, but it's not a requirement for self-build AUR packages. Who shares binary packages from AUR ?
Anybody can share binary packages that they build off of AUR buildscripts -- that is exactly what we allow by making these flags the default.
With local optimization, users end up spending time rebuilding. You may build a bunch of packages and decide to share them from a repo, or you may want help from somebody else with runtime problems that you're having.
There is no statistical backing here AFAIK, so if you feel strongly about it, you are welcome to approach the pacman developers in order to reach a new conclusion.
Remember also that gcc optimization flags make difference only for programs which run in or close to realtime. Examples include lapack/arpack, blender, or your own HPC code. For everything else advanced optimization via -march= and -O? flags yields no measurable performance increase. Even if you build e.g. thunderbird using -O1 for a generic x86_64 machine, you'll not notice any slowdown compared to an "optimized" build (actually, that's how I build all my local packages). Cheers, -- Leonid Isaev GPG fingerprints: DA92 034D B4A8 EC51 7EA6 20DF 9291 EE8A 043C B8C4 C0DF 20D0 C075 C3F1 E1BE 775A A7AE F6CB 164B 5A6D