jtr485@umich.UUCP (02/08/87)
In article <8702070057.AA17890@amdcad.AMD.COM>, bandy@amdcad.UUCP.UUCP writes: > Well, given his constraints, he did port it to a decent machine - there > isnt' a single cheap 68k system on the market that has a mmu in it, yet the > 8086 family has had one since day one (well, not exactly an mmu, but it will > provide some protection against run-away programs if the compiler doesn't > generate instructions that twiddle the segment registers). > > Anyhow, in order for us to do a 68k port we could do one(?) of the following: > > 2) Hack up Stallman's gnu c compiler so it will generate PIC (but what to > do when you take the address of a variable on the stack?) >--andy What is special about addressi on the stack? If your going to do position independent code, and are willing to take the same penalties as the 8086 family, then you use register relative addressing. That is, you turn some A registers into segment registers. --j.a.tainter