On Mon, Feb 26, 2018 at 05:24:28AM +0100, Kevin Kofler wrote:
> Zbigniew Jędrzejewski-Szmek wrote:
> > But size is easy:
> > $ du -s /var/tmp/inst-O*
> > 74428 /var/tmp/inst-O3
> > 56136 /var/tmp/inst-O3-lto
> > 61992 /var/tmp/inst-Os
> > 43572 /var/tmp/inst-Os-lto
>
> The current default is -O2, not -O3, though.

Heh, I'm a bit surprised:

74428    /var/tmp/inst-O3
56136    /var/tmp/inst-O3-lto
61992    /var/tmp/inst-Os
43572    /var/tmp/inst-Os-lto
71268    /var/tmp/inst-O2
50276    /var/tmp/inst-O2-lto
47928    /var/tmp/inst-O0
32688    /var/tmp/inst-O0-lto

So... I'd say that lto *does* give a measure benefit.
(Note, it's all unstripped.)