c/n1/i386/tables/Read_me 5/15/92

This directory contains modified versions of i386 assign.t and leaves.t.
The currently used versions generate widen conversions and widening
assignments as follows:
	shorter:	longer:		using:
	signed		signed		sign-extend
	signed		unsigned	sign-extend
	unsigned	signed		zero-extend
	unsigned	unsigned	zero-extend
That is, the left type determines whether sign-extend or zero-extend
is used.

This is obviously the desired behavior for
	signed		signed		sign-extend
	unsigned	unsigned	zero-extend
But it seems more reasonable to zero-extend in both the cross-type cases:
	signed		unsigned	zero-extend
	unsigned	signed		zero-extend
That is,
	(char)255 should become (unsigned)255, not (unsigned)0xFFFFFFFF,
and
	(unsigned char)255 should become (int)255, not (int)-1.
The tables in this subdirectory implement this change.
However, they are not currently used for the distribution compiler,
because the result produces numerous consistency errors from the unop
and binop tests which need to be investigated.
