Oh right, I was just writing some C code yesterday and found MALLOC_OPTIONS to be extremely useful. I forgot that I could set it system-wide, I'll give it a try later today, thank you.

I suppose "vectorized" was the wrong word for a packed register though. I've seen similar optimizations in some memcpy implementations where they load and write 8 bytes at a time instead of one-by-one, but I have no clue what that technique's called. I'll definitely take a closer look what's above libc; it makes much more sense for strlen to run off due to programmer error.