Re: Slim lto objects

[Jan Hubicka <hubicka at ucw dot cz>]

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