尝试在cygwin上运行xsim命令时出现以下错误。请帮助，让我知道我最后缺少什么？
kap@kap-PC /cygdrive/d
$ echo $XILINX_VIVADO
D:/XilinxV/Vivado/2015.2
kap@kap-PC /cygdrive/d
$ echo $VIVADO
D:\XilinxV\compile_simlib
kap@kap-PC /cygdrive/d
$ xelab
D:/XilinxV/Vivado/2015.2/bin/unwrapped/win64.o/xelab.exe: error while loading shared libraries: ?: cannot open shared object file: No such file or directory