Brian Gerst wrote: > If you really want to test the math emu code, you can hack check_x87 > in head.S to always leave the fpu disabled. Then you can test it on > any cpu, not just a 386. That is a good idea, and while a valid point, it actually still requires writing the code to actually test the FPU, specifically, using weird prefixes, LDT based segments, and other oddities that don't get generated from "normal" C code. I'm pretty sure the existing code works for the 99% cases or else it wouldn't have gotten there in the first place. But testing the corner cases here is even nastier than testing the LDT corner cases - you would basically need to write a lot of hand coded i387 assembler. Perhaps such a test might exist, but in all honesty, without a comprehensive test, it is simply far too easy to introduce a bug here, and far too likely it will either not be noticed until it has caused someone a possibly undetected numerical error, or I'm just wasting my time because noone is using this code anyways. Fortunately, the Hubble telescope has been upgraded to a 486 ;) Zach
