http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50131
--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> 2011-08-20 19:44:49 UTC --- (In reply to comment #2) > Is or $-1, reg on all CPUs equally expensive to mov $-1, reg though (as or > generally needs the previous reg content while mov does not; I know some CPUs > special case xor reg, reg, but I doubt or $-1, reg is special cased)? We should add a new x86 optimization flag and turn it on only if it helps for the processor to be optimized.
