Segment Base Register Usage Issue

[occia]

First,in the gentrace.cpp,you add FS & GS registers into the operand_pre_list.But you define its usage as 0,and usage macro define is here,which means FS&GS has no usage,no RD and no WR.

Second,in the frame_events.ml,the no usage op will be ignored.
The above means,if I use gentrace.so to generate a trace.frame and use Frame_events.of_frame function to parse it,I will lose all segment base register(FS&GS).And I found this because I can't find any FS or GS register in the trace dump file when I use bap's --trace-dump option.

Does no usage FS&GS is designed on purpose or just an issue?

Any help is highly appreciated,thanks~