Dead-code elimination can't remove string copy insns?

[Michael Matz]

Hi,

On Tue, 13 May 2003, Richard Henderson wrote:

> On Tue, May 13, 2003 at 11:30:12AM +0200, Michael Matz wrote:
> > Exactly.  We don't track dead stores to memory.
>
> Well, we do, but it only works on tail blocks.

I know.  But this uses the mem expressions to represent the stored-into
memory, and hence doesn't work on BLKmode mems.  I guess one could special
case Zacks example by noting (for the tail blocks), that all stores to
stack mem are dead if there is _no_ read from stack afterwards.  But this
special casing quickly becomes silly.


Ciao,
Michael.