I tried to simulate cvfpu(a floating-point unit written in SystemVerilog) with iverilog, but the compiler gave up every time when there was parameter int unsigned in source code even if I added -g2005-sv. Does it mean that int unsigned is not supported by iverilog? And I'll also be appreciated that you can tell me how to simulate SystemVerilog codes, like cvfpu, with iverilog (not vcs).
iverilog does not support all SystemVerilog features.
I tried a trivial example on EDA Playground using the latest version of iverilog which is available there, and it also generates a syntax error. It uses the -g2012 option to enable SystemVerilog features. The example compiles without errors with other simulators on that site.
If you want to continue to use iverilog, you can try to contact the developers to see if a newer version is available.
Otherwise, you need to use a different simulator to run simulations with this syntax.