Right, sorry about the delay. Current status: I'm .. stuck, for lack of a better word.
Deheapifying flite has proven almost impossible. Long story short, I traced every malloc call and have a pretty good idea which ones can be grouped together and moved to the stack (at the cost of some wasted memory). However, the majority of the malloc calls cannot be removed. I was convinced it was a peculiarity of the implementation but it looks like it's a fundamental requirement of the engine. Not only will the lack of malloc break encapsulation (a HUGE number of extern globals would have to be introduced) but it would actually require much more memory than the heap version. So the question here is whether malloc in core (even as a loadable component) is an absolute no-do. I'm not going to try and hide the ugly truth - the memory fragmentation is MASSIVE, even with something like tlsf. I've converted most of the synthesis process into fixed-point, however the speedup is negligible still. I'm starting to see why Google chose eSpeak for Android. :(
