We are using CW for Coldfire.
File modification dates do not seem to affect the binary even with debug data included. When I touch a source file, or make a non-code change such as adding comments, the output is unaffected.
We do not happen to use __TIME__ in these projects, and differences are substantial, not just a few bytes here and there.
I was able to build GNU binutils for m68k-elf under Cygwin, but objdump has some problems with the CW Coldfire format. However, ar works and lists the objects in the same order in the library, so I think that much is the same. Some of the object files are the same, too. With readelf, and now with disassembly in CW, I see that the differences in a particular object file are the addends to .debug for most of the relocation entries in the .rela.debug sections.
What are "recursive directories" for which search order is undefined?