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

[Diego Novillo <dnovillo at redhat dot com>]

On Tue, 2003-05-13 at 12:17, Zack Weinberg wrote:
> Michael Matz <matz@suse.de> writes:
> 
> >> but the alias information should be sufficient to see that the memory
> >> region being written into is on the stack, and unused past this insn,
> >> hence the store is dead and can be deleted.
> >
> > It should, but we don't do that currently.
> 
> Do you have a sense for how hard this would be to implement?  Is it
> something that's done on tree-ssa, so there's no point adding it in
> mainline?  Will Naveen's stack-slot allocator help?
> 
If you show me the original source code I could tell you.  Once things
are in RTL form, it's difficult for me to trace them back into trees. 
There's also the situation in which we have dead code at the RTL level
that it's impossible to detect at the tree level (e.g. address
arithmetic for array references).


Diego.