idea

[William_Lott@ARDATH.SLISP.CS.CMU.EDU]

Rob,

So you should make the register allocator allow two different TNs in the
same location if one is a copy of the other and neither is written during
the lifetime of the shorter.  In other words, when you have something like:

	(sap< foo bar)

which gets transformed into:

	(< (sap-int foo) (sap-int bar))

you currently will get something like:

	mov	t1, foo
	mov	t2, bar
	cmp	t1, t2

when it could have just used foo and bar directly.

-William