A test [istarget x86_64-*-gnu] is wrong; i?86-* -m64 should always be handled exactly the same as x86_64-* -m64.
You need to work out which ABIs (-m32, -mx32, -m64) this testing is meaningful for. Then, allow both x86_64- and i?86- targets, together with an appropriate effective-target test ("lp64" to allow just -m64, for example). -- Joseph S. Myers jos...@codesourcery.com