https://bugs.winehq.org/show_bug.cgi?id=34867
--- Comment #32 from Sagawa sagawa.aki+winebugs@gmail.com ---
From my point of view, we need the following parts to achieve FPU handling in
16-bit code: Part 1) Set the exception handler into TDB (task data base) inside win87em's _fpmath (BX=3). Win16's TDB has a member named int75. I think it is a good place to save the handler. I'm not sure whether TDB.int75's handler is compatible with win87em's argument. Part 2) Call TDB.int75 handler when the FPU exception occurs. We need investigate where we should call the handler and how do that.
Since I'm not familiar with Win16 exception handling, above assumptions should be verified.
Another point of view, Open Watcom v2 has setup routine for win87em[1]. [1] https://github.com/open-watcom/open-watcom-v2/blob/5d9c9c3109647a5c55880b961...