http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56700
uran238 at web dot de changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |
--- Comment #2 from uran238 at web dot de 2013-03-26 18:46:25 UTC ---
> where did you get this info from?
>From the man page:
<snip>
The only important thing to keep in mind is that to enable link-time
optimizations the -flto flag needs to be passed to both the compile and the
link commands.
[...]
Additionally, the optimization flags used to compile individual files are not
necessarily related to those used at link time. For instance,
gcc -c -O0 -flto foo.c
gcc -c -O0 -flto bar.c
gcc -o myprog -flto -O3 foo.o bar.o
This produces individual object files with unoptimized assembler code, but the
resulting binary myprog is optimized at -O3. If, instead, the final binary is
generated without -flto, then myprog is not optimized.
</snip>
Misleading at best.
If "the resulting binary" "is optimized at -O3", but that's not the same as
optimizing the individual object files and the resulting binary at -O3, that's
definitely worth mentioning.
Please clarify that in the man page. It's not just me who concluded that wrong.
