https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108498
--- Comment #3 from Adam Stylinski <kungfujesus06 at gmail dot com> --- (In reply to Andrew Pinski from comment #2) > This might be a valgrind bug of not tracking bits correctly for some ppc > instructions. It's most certainly not, though. That bit is explicitly being set to 0 from an integer and with the optimization enabled it's printing 1.