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To: Michael Matz <matz@suse.de>
Cc: gcc@gcc.gnu.org
Subject: Re: Dead-code elimination can't remove string copy insns?
References: <Pine.LNX.4.44.0305131128250.15564-100000@wotan.suse.de>
From: Zack Weinberg <zack@codesourcery.com>
Date: Tue, 13 May 2003 16:17:00 -0000
In-Reply-To: <Pine.LNX.4.44.0305131128250.15564-100000@wotan.suse.de> (Michael
 Matz's message of "Tue, 13 May 2003 11:30:12 +0200 (CEST)")
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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?

zw