On Tue, Feb 7, 2012 at 9:27 AM, Andi Kleen <a...@firstfloor.org> wrote: > Richard Guenther <richard.guent...@gmail.com> writes: >> >> You then can do >> >> gcc $OPTIONS -flto a.c -o a.o >> gcc $OPTIONS -flto b.c -o b.o >> gcc $OPTIONS -ffixed-r9 -ffixed-r10 -flto d.c -o d.o >> gcc $OPTIONS -ffixed-r9 -ffixed-r10 -flto e.c -o e.o >> gcc $OPTIONS -flto a.o b.o -o non-fixed-reg-part.o -r -nostdlib >> gcc $OPTIONS -flto -ffixed-r9 -ffixed-r10 d.o e.o -o fixed-reg-part.o >> -r -nostdlib >> gcc non-fixed-reg-part.o fixed-reg-part.o >> >> thus, optimize both pieces via partial LTO linking (-r, maybe the -nostdlib >> is >> not needed) and then do the final link separately. > > Note that ld -r with LTO has some problems in 4.6, it will work fully > reliable. This has been fixed in 4.7.
well he is not using ld directly so we go through the LTO path instead. -- Pinski
