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Re: [PATCH 2/5] dce: Don't dead-code delete separately wrapped restores

From: Jeff Law <law at redhat dot com>
To: Segher Boessenkool <segher at kernel dot crashing dot org>, gcc-patches at gcc dot gnu dot org
Cc: dje dot gcc at gmail dot com
Date: Mon, 26 Sep 2016 10:39:55 -0600
Subject: Re: [PATCH 2/5] dce: Don't dead-code delete separately wrapped restores
Authentication-results: sourceware.org; auth=none
References: <cover.1474616087.git.segher@kernel.crashing.org> <e8a1ae7870bbbd8d70d55483b24e014d0c4713fe.1474616087.git.segher@kernel.crashing.org>

On 09/23/2016 02:21 AM, Segher Boessenkool wrote:

If there is a separately wrapped register restore on some path that
is dead (say, control goes into an endless loop after it), then we
cannot delete that restore because that would confuse the DWARF CFI
(if there is another path joining after this).
This happens with gcc.dg/torture/pr53168.c, for example.


2016-09-23  Segher Boessenkool  <segher@kernel.crashing.org>

	* dce.c (delete_unmarked_insns): Don't delete instructions with
	a REG_CFA_RESTORE note.

OK and can go in now IMHO.
jeff

References:
- [PATCH v3 0/5] Separate shrink-wrapping
  - From: Segher Boessenkool
- [PATCH 2/5] dce: Don't dead-code delete separately wrapped restores
  - From: Segher Boessenkool

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