Here's how to decompile Nvidia CUDA .cubin files into assembly and compare them in Beyond Compare 3's Text Compare.

Download and install the Nvidia Cuda Toolkit 4.1.

Create the batch file:
C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v4.1\bin\cuobjdump2file.bat

Contents of the file:
"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v4.1\bin\cuobjdump.exe" --dump-sass %1 > %2

In Beyond Compare, select "Tools > File Formats".
Click "New".
Select "Text Format" as the type.
Name the format Nvidia Cubin.
Enter *.cubin as the mask.
Go to the Conversion tab.
Change conversion from "None" to "External program (Unicode filenames)".
In "Loading", enter:
C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v4.1\bin\cuobjdump2file.bat %s %t
Save the format.

Opening .cubin files in Beyond Compare will display them decompiled into assembly code in the Text Compare.