** Warning: (vlib-34) Library already exists at "work".
# ** Error: (vcom-11) Could not find work.std_logic_arith.
# ** Error: iu.vhd(29): (vcom-1195) Cannot find expanded name "work.std_logic_arith".
# ** Error: iu.vhd(29): Unknown expanded name.
# ** Error: (vcom-11) Could not find work.std_logic_unsigned.
# ** Error: iu.vhd(33): (vcom-1195) Cannot find expanded name "work.std_logic_unsigned".
# ** Error: iu.vhd(33): Unknown expanded name.
# ** Error: (vcom-11) Could not find work.std_logic_unsigned.
# ** Error: iu.vhd(34): (vcom-1195) Cannot find expanded name "work.std_logic_unsigned".
# ** Error: iu.vhd(34): Unknown expanded name.
# ** Error: (vcom-11) Could not find work.std_logic_unsigned.
# ** Error: iu.vhd(35): (vcom-1195) Cannot find expanded name "work.std_logic_unsigned".
# ** Error: iu.vhd(35): Unknown expanded name.
# ** Error: iu.vhd(45): VHDL Compiler exiting
# ** Error: /mnt/iscsi/mgc/AMS/questasim/v6.4c/linux/vcom failed.
# Error in macro ./compile.bat line 47
# /mnt/iscsi/mgc/AMS/questasim/v6.4c/linux/vcom failed.
# while executing
# "vcom -quiet iu.vhd "