`march=native` on fedora with clang seem to fail to detect the right target: ``` error: unknown target CPU 'pentium-m' ``` https://ci.inria.fr/linbox/job/Givaro/Archi=linbox-fedora,Compiler=clang++/257/
march=nativeon fedora with clang seem to fail to detect the right target:https://ci.inria.fr/linbox/job/Givaro/Archi=linbox-fedora,Compiler=clang++/257/