What Flags must be modified in order to get CODER to produce 64 bit code on a 64 bit Linux computer

I have a 64 bit Linux machine with 256 Gig of memory. I want to use CODER to create a MEX routine with the expectation of a roughly x50 speed up of my algorithm. My data sets are 3D and require 64 bit processing. Running my code in standard matlab works fime but I require the speed up. To my surprise when running 64 bit matlab application named CODER to produce a MEX file. CODER (by default) creates 32 bit MEX functions. I have not found any documentation which explains which files, and which flags, need to be modified to get CODER to produce 64 bit code. Many Thanks to anyone who can elaborate on a fix.