As an aside, I'm starting to look at this sort of thing for escape
analysis for stack allocation. As is, I'm using alloca. However, I
believe that there is no specfic requirement to dynamically allocate
on the stack using alloca, and that doing so would hinder the use of
-fomit-frame-pointer?
I'm afraid I don't understand this patch too well, nor the problem
it's solving, but I'm wondering are you preallocating space on the
stack by increasing the frame size at compile time, or are you
fiddling with the frame pointer at run time, or some other way? If the
former, it seems this has benefits over using alloca.