Re: working around "QImode can alias everything" missed optimizations

[Doug Evans <dje at transmeta dot com>]

Richard Henderson writes:
 > On Fri, May 26, 2000 at 03:43:55PM -0700, Doug Evans wrote:
 > > (I'm guessing because it can't know that buf may point to itself
 > > and QImode values are allowed to alias anything).
 > 
 > Yep.
 > 
 > > So how do I work around this?
 > 
 > You can't.  :-(

I was afraid you were going to say that.

Any interest in fixing this [dunno how yet]?
GCC produces great code for non-QImode values (well done!).
It has to be agreed that QImode values shouldn't be penalized (right?).
[not that I would change behaviour of course, but rather that some
new way of specifying a "ya, I'm a QImode (ptr) value but, gosh darn it,
I don't alias everything" value needs to be found.  Alternatively, one
might come up with another way, but this way seems at first glance
like the right way to go.  I tried playing with `restrict' but I
don't know enough about it yet to say whether that has a chance
of working - I reread jfc's original email regarding his `restrict'
patch and he said there'd be problems with inline fns].