if executable('WinMergeU')
    command! -nargs=+ -complete=buffer WinMergeU :call <SID>:executeWinmerge(<f-args>)

    function! <SID>:executeWinmerge(...)
        if len(a:000) < 2
            return
        endif

        let file1 = fnamemodify(a:1, ':p')
        let file2 = fnamemodify(a:2, ':p')

        execute '!start WinMergeU ' . file1 . ' ' . file2

    endfunction

endif