https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70454
--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> --- By default, gcc uses the same -march=xxx for both -m32 and -m64 on x86-64 unless --with-arch-32= is used. There is no need for -march=i486 for -m32 on x86-64.
