Allocation in vm/i386/jitinterfacex86.cpp

Hi,
 the functionality of the EmitCore routine in the file jitinterfacex86.cpp
is clear, but i am not able to decipher the following..
After one checks whether alloc request can be satisfied EDX contains the
updated heap address (old address + allocation size). How does the control
flow, pass on this updated address to the caller. the series of emit calls
puts the code generated into a memory buffer as i understand. After that
what follows isnt clear.
Also am i right in assuming that the allocator in EmitCore doesnt
consider registering finalizable objects etc.. since its just a bare-bones
allocator
can someone pls help

thanks & regards
archana