i/d fp simulator

[utzoo!decvax!ucbvax!unix-wizards]

>From JNC at MIT-XX Thu Nov 12 22:50:24 1981
	With a standard machine running I/D, there is no way to look
at the faulted instruction in user mode. There are two ways to fix this;
one is to hack the processor so that user MFPI works, the other is to
add a system call to do the equivalent. We have an fp1.s that uses the
system call, and we are using that at the moment, but I am just about
(this morning) to implement the MFPI fix. If you want, I can tell you
what to do. If you want the code, let me know.
	Does anyone have an fp1.s that does the lookahead optimization?
I tried doing it, and it seemed to work, but after a while it blows
up, and I can't figure out why.
		Noel
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