We talked at Connect about finishing up the cortex-strings work by upstreaming them into Bionic, Newlib, and GLIBC. I've written up one of our standard 'Output' pages:
https://wiki.linaro.org/WorkingGroups/ToolChain/Outputs/CortexStrings
with a summary of what we did, what else exists, benchmark results, and next steps. This can be used to justify the routines to the different upstreams.
The Android guys are going to upstream these to Bionic. I need a volunteer to do Newlib and GLIBC.
One surprise was that the Newlib plain C routines are very good on strings - probably due to a good end of string detector.
-- Michael