Why would it be pointless? A region of the heap which malloc can return doesn’t sound too problematic at all, nor would it have significant performance penalty.

Why would it be pointless? A region of the heap which malloc can return doesn’t sound too problematic at all, nor would it have significant performance penalty. Getting pointers to stack variables is a bit more cumbersome, but you can just escape analyze functions, and store in a heap-allocated ByteBuffer stack variables that might be dereferenced.