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

From: Dale Johannesen <dalej at apple dot com>
To: Zack Weinberg <zack at codesourcery dot com>
Cc: Dale Johannesen <dalej at apple dot com>, gcc at gcc dot gnu dot org
Date: Mon, 12 May 2003 17:47:18 -0700
Subject: Re: Dead-code elimination can't remove string copy insns?

On Monday, May 12, 2003, at 05:26 PM, Zack Weinberg wrote:

Why can't anything delete these insns? I'm guessing it has something
to do with the BLKmode memory access, 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.

Can it tell the region's address hasn't been taken and stored somewhere?

Full dumps on request.  The above snippets are from the .life dump.
The input file is gcc.dg/const-elim-1.c.

Follow-Ups:
- Re: Dead-code elimination can't remove string copy insns?
  - From: Zack Weinberg

References:
- Dead-code elimination can't remove string copy insns?
  - From: Zack Weinberg

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