Re: More MEM tracking stuff

[kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)]

    what's the ultimate goal of these changes?  Improving alias analysis
    seems to be one point but what are you also trying to achieve?  Feel
    free to answer publically on the list since others might be interested
    - or where should I look for some explanation?

There are basically three things:

(1) Alias analysis can indeed be improved by knowing the underlying decl
for each MEM.

(2) With the recording of a decl for each MEM, the assembler output can
be annotated with the variable name for easier reading.  This has been
completed.

(3) By recording the alignment of a MEM inside the MEM, the kludge of
expand_expr_unaligned can be removed and we can also simplify the
alignment handling in tree expansion.  A major goal here is to get rid
of the copying we do in a lot of such cases.  This work is about half done.