[scott_wilson46]

I use Icarus Verilog at work for a fairly complex trading system on an FPGA so I disagree that FOSS simulators are almost totally useless. It supports most System Verilog features and works well with cocotb. In fact the fact that it’s open source also allows me not to have to worry about license usage (which has always been a problem using modelsim). I managed quite well abstracting the Xilinx is (most up like rams can be inferred in the code) and things like pcie, transceivers, ddr4 have well defined interfaces so are easy to model in straight Verilog

[analognoise]

You use Icarus for a trading system - exclusively, or when you can't get a license checkout for something better?

I can't imagine a FinTech shop wouldn't have access to MSim (or Questa).

[scott_wilson46]

I use it exclusively. I know of other trading firms that use verilator too. To be honest, no matter how big the company, how deep the pockets, theres still going to be a finite amount of questa licenses available. If you use Icarus Verilog it allows you to farm out simulations to anywhere, run as many in parallel, which would not be possible with questa (as you would eventually run out of licenses). Also, I think icarus verilog actually works pretty well, it covers enough of the system verilog syntax to be useful for RTL and with cocotb I don't need access to the system verilog testbench stuff.