Pre_dec and Post_inc insns

[Alexandre Oliva]

On Jun 30, 2003, "Natasha Wilson" <nat_w@operamail.com> wrote:

> What are the potentials areas where they could create problems if
> they are generated before the flow pass?

I just found out, the hard way, that cse is one such area.  It simply
doesn't notice changes caused by autoinc modifiers, and it may also
replace pseudos that are marked as equivalent to constants, and then
reload barfs.

Unfortunately, cse may also turn increments that flow could turn into
autoinc addressing modes into computations of a base register plus a
constant, which flow then can't handle.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer