reverse enginner to compare library compiled with ADS and RVCT compiler

i have a library which contains objs compiled for rvct compiler ( language used in c or c++). other one is complied for ADS.

I want to reverse engineer and produce some sort of c /c++ code out of it.The motive is to find out what is causing difference in memory size occupied by similar code.

a) is it possible to do so b) if yes , how to do it using free software.

I am no开发者_如何学Got looking for very accurate output , just some sort of output by which i can compare two such different objs .

Is there other way to do this comparison ..i mean some tool which can look into machine code and give me some sort of comparison of memory consumption.

If you want C code, the only way is Hex-Rays ARM Decompiler (disclaimer: I work for Hex-Rays). You can get by using free stuff for disassembly, e.g. GNU objdump from binutils (-d switch).