Andi Kleen wrote: > On Sun, Jan 11, 2009 at 04:21:03PM -0800, Linus Torvalds wrote: >> >> On Mon, 12 Jan 2009, Andi Kleen wrote: >>> so at least least for this case it works. Your case also doesn't work >>> for me. So it looks like gcc didn't like something you did in your test >>> program. >> I very intentionally used _different_ types. >> >> If you use the same type, gcc will apparenrly happily say "hey, I can >> combine two variables of the same type with different liveness into the >> same variable". > > Confirmed. > >> But that's not the interesting case. > > Weird. I wonder where this strange restriction comes from. Something at the back of my mind said "aliasing". $ gcc linus.c -O2 -S ; grep subl linus.s subl $1624, %esp $ gcc linus.c -O2 -S -fno-strict-aliasing; grep subl linus.s subl $824, %esp That's with 4.3.2. Bernd -- This footer brought to you by insane German lawmakers. Analog Devices GmbH Wilhelm-Wagenfeld-Str. 6 80807 Muenchen Sitz der Gesellschaft Muenchen, Registergericht Muenchen HRB 40368 Geschaeftsfuehrer Thomas Wessel, William A. Martin, Margaret Seif -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html