https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78023
--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to David Binderman from comment #0) > Created attachment 39831 [details] > C source code after creduce > > The attached C code, when compiled by gcc trunk dated 20161018, > and compiler flags -O3 -march=native, does this: BTW: Please note that -march=native gets replaced with true -march=... and a bunch of -mABI options by the compiler driver. You can see options, passed by the driver, by adding -### to the compiler flags. Please report -march=... that is determined by the driver. Usually, this is enough to reproduce the bug, for some unusual targets (e.g. emulators) please also report other -m... options. > The processor has this in /proc/cpuinfo This info is useless and redundant when true -march= is reported.