Re: [PATCH 2/2] refactor emit_*_{after,before}{,_setloc} using common functions

[Nathan Froyd <froydnj at codesourcery dot com>]

On Wed, Mar 23, 2011 at 01:55:34PM -0700, Richard Henderson wrote:
> I can't see how emitting a NULL_RTX should be a Good Thing, ever,
> and thus I don't see why we should be doing special things to 
> handle it.

Ah, I thought the same thing and gcc_assert'ed emitting a NULL_RTX.  I
didn't get very far; at least reload (and possibly other places) assume
that they can do something like:

    x = NULL_RTX;
    ...do something maybe setting x to a useful pattern...
    ...emit x unconditionally...

I can look into just how many places might need to be fixed up because
of this, but scattering a bunch of ifs all over the place seemed less
elegant than handling it all in the emit* functions.

-Nathan