Please add ~mips keyword to net-misc/bridge-utils. They compile and work fine on MIPS. Given that there is a wide proliferation of small MIPS architecture wireless routers it would be a good thing to make this package emerge without adding "**" keyword to package.keywords.
Tests okay on lemote = loongson mips64 little endian N32 MIPS-III glibc-2.13-r4. Since you mentioned routers, I also tested on an mikrotik rb450g = atheros ar7161 mip big endian O32 MIPS-III uclibc-0.9.32.1. I'll keyword it.