Diffing all files in all subdirectories

Note to self... to diff all the files in all subdirectories in cygwin, type:

$ cd /cygdrive/c/d1

$ dir2=/cygdrive/c/d2; out1=/cygdrive/c/outfile.out; rm "$out1"; for dir1 in $(find . -type d); do ( for file in ${dir1}/*; do echo "${dir1}/${file}">> "$out1"; echo "${dir2}/${file}">> "$out1"; diff "${dir1}/${file}" "${dir2}/${file}" >> "$out1"; done ); done;

based on: http://askubuntu.com/questions/111495/how-to-diff-multiple-files-across-directories

There's probably some fancy tool that does this too, like windiff or something.  This way is pretty noisy.