On 7 May 2013 17:17, Andrey Semashev wrote:
I also think it shouldn't do that. I suppose the reason is due to a limitation of Boost.Build that needs to know what the default is. Most GCC 32-bit binaries will build for i386 by default, even on modern linux distributions.
Not for Ubuntu 13.04, at least.
gcc -m32 -dM -E - < /dev/null | grep __i686__ #define __i686__ 1
I also read that Fedora and Mandriva moved to i686 by default (probably, emulating cmov in kernel if running on i586) [1].
And Linux kernel dropped support for 80386 CPUs. [2] I actually read they dropped all CPUs without cpuid (which also includes some 80486) somewhere else, but I can't find it now. FreeBSD removed support for 80386 in 6.0 ([3], [4]). OpenBSD doesn't support both 80386 and some 80486 [5].
NetBSD dropped 80386 support too: http://mail-index.netbsd.org/tech-toolchain/2009/02/24/msg000582.html