Joanna Pierożek <akai@xxxxxxxxxxxxxxxxx> writes: > Setting -march=native and -mtune=native flags on a Via Nano U2250 > produces Core2 optimized code that works very poorly on this CPU > (programs fail or don't compile). I wonder if it was a conscious > decision of GCC developers to set -march=native options for Via Nano to > these values? It was not a conscious decision. As far as I know there is no specific support in gcc for the Via Nano. This is the kind of thing which is normally contributed by some interested party with a copy of the detailed instruction architecture and timings for the processor. That said, I can understand why a program might run slowly when using -mtune=native. But I don't understand why a program would fail to compile. If a program fails to run when using -march=native, presumably due to the use of some instruction not available on the processor, then please file a bug with a test case, following the instructions at http://gcc.gnu.org/bugs.html . Thanks. Ian
