Hi, I build Mozilla without debug info with slim LTO and non-LTO. slim LTO build is:
real 14m26.882s user 78m47.547s sys 6m58.870s jh@evans:/abuild/jh/build-mozilla-new14> du -s . 1056120 . jh@evans:/abuild/jh/build-mozilla-new14> size toolkit/library/libxul.so text data bss dec hex filename 46552709 3585416 381640 50519765 302ded5 toolkit/library/libxul.so non-LTO build is: real 13m19.251s user 61m21.386s sys 7m28.672s jh@evans:/abuild/jh/build-mozilla-new14-no-lto> du -s . 424224 . jh@evans:/abuild/jh/build-mozilla-new14-no-lto> size toolkit/library/libxul.so text data bss dec hex filename 32403100 2659736 385224 35448060 21ce4fc toolkit/library/libxul.so So one needs about extra minute and twice as much of disk space for LTO. The libxul binary is a lot bigger ATM, not quite sure why because non-slim binary is still bigger but not that much. So there must be some bug. It is -O3 binary so unless --param inline-unit-growth is tuned down it is supposed to be bigger than non-LTO. Memory use is about 3.2GB. Honza
