Whenever I've seen 'file not found' from an executable or ldd on Gentoo-ARM it has been because the dynamic linker named in the ELF doesn't exist.
It's easy to debug - just load the executable into your editor of choice and look for /lib/ The string will be in the first few hundred characters. Here's some examples from today (2014.07.13), using the latest firmware in GIT:
I have *both* these on my RPi, despite the fact that it is built with "-mfpu=vfp -mfloat-abi=hard", but I think that at some point I might have had to fix up one or other of them. IRC a GCC update changes, and maybe removes, them. Nevertheless both vcgencmds fail with 'VCHI initialization failed'; it's not a very well written program
[if (geteuid() != 0) somewhere maybe?]