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Re: Fix PR optimization/7520

From: "Eric Botcazou" <ebotcazou at libertysurf dot fr>
To: "Richard Henderson" <rth at redhat dot com>
Cc: <gcc-patches at gcc dot gnu dot org>
Date: Thu, 19 Sep 2002 10:57:19 +0200
Subject: Re: Fix PR optimization/7520
References: <005e01c25f67$a1758920$31bf53d4@zephyr> <20020919000404.GG11853@redhat.com>

> > The proposed fix is to let this mecanism trigger in this latter case when
> > the clobbered register is live after the insn, so as to prevent the REG_DEAD
> > note from being attached.
>
> That is incorrect.  In the case of use+set, the value is live
> after the insn.  In the case of use+clobber, it isn't.

What is exactly incorrect ? To say "when the clobbered register is live
after the insn" or the proposed fix ? In the former case, is "when the
clobbered register is live at the next insn" more correct ? Or do you mean
that a clobbered register must never be live at the next insn ?

--
Eric Botcazou

Follow-Ups:
- Re: Fix PR optimization/7520
  - From: Richard Henderson

References:
- Fix PR optimization/7520
  - From: Eric Botcazou
- Re: Fix PR optimization/7520
  - From: Richard Henderson

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