From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: Dibyendu Majumdar <mobile@majumdar.org.uk>
Cc: Linux-Sparse <linux-sparse@vger.kernel.org>
Subject: Re: Potential incorrect simplification
Date: Tue, 28 Mar 2017 16:11:14 +0200 [thread overview]
Message-ID: <20170328141113.kbrwdva6ttsrokts@macpro.local> (raw)
In-Reply-To: <CACXZuxfxNNh+ThcT=7Xr98tToL2GimFi7UOTSwgNq6mfLLGNfA@mail.gmail.com>
On Tue, Mar 28, 2017 at 02:58:57PM +0100, Dibyendu Majumdar wrote:
> Hi Luc,
>
>
> The first instruction and.32 refers to %r4 which is undefined.
Yes, I saw.
This %r4 corresponds (somehow) to s3 which isn't initialized.
But yes, there is two problems here:
*) we should use something explicit, like VOID
*) there is a circulary dependence between %r3 & %r4, the first %r4
being obviously wrong.
I suspect there is a lot of problems present once there is some
undefined variables.
Thanks for the repoort.
-- Luc
next prev parent reply other threads:[~2017-03-28 14:11 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-28 12:40 Potential incorrect simplification Dibyendu Majumdar
2017-03-28 13:34 ` Luc Van Oostenryck
2017-03-28 13:58 ` Dibyendu Majumdar
2017-03-28 14:11 ` Luc Van Oostenryck [this message]
2017-03-28 14:19 ` Dibyendu Majumdar
2017-03-28 16:20 ` Linus Torvalds
2017-03-28 17:00 ` Luc Van Oostenryck
2017-03-28 18:02 ` Linus Torvalds
2017-03-28 20:27 ` Luc Van Oostenryck
2017-03-28 21:57 ` Linus Torvalds
2017-03-28 22:28 ` Luc Van Oostenryck
2017-03-28 22:22 ` Dibyendu Majumdar
2017-08-06 12:46 ` Christopher Li
2017-08-06 14:00 ` Luc Van Oostenryck
2017-08-06 14:24 ` Christopher Li
2017-08-06 14:54 ` Christopher Li
2017-08-06 15:07 ` Luc Van Oostenryck
2017-08-06 15:51 ` Christopher Li
2017-08-06 16:51 ` Luc Van Oostenryck
2017-08-06 18:35 ` Christopher Li
2017-08-06 19:51 ` Dibyendu Majumdar
2017-08-06 20:08 ` Luc Van Oostenryck
2017-08-06 19:52 ` Luc Van Oostenryck
2017-08-06 23:34 ` Christopher Li
2017-08-07 0:31 ` Luc Van Oostenryck
2017-08-07 0:38 ` Christopher Li
2017-08-06 15:52 ` Dibyendu Majumdar
2017-08-06 16:56 ` Luc Van Oostenryck
2017-08-06 17:04 ` Dibyendu Majumdar
2017-08-06 17:45 ` Luc Van Oostenryck
2017-08-06 17:58 ` Dibyendu Majumdar
2017-08-06 18:15 ` Luc Van Oostenryck
2017-08-06 18:18 ` Dibyendu Majumdar
2017-08-06 18:31 ` Luc Van Oostenryck
2017-08-07 19:11 ` [PATCH v2 0/8] fix loading of partially defined bitfield Luc Van Oostenryck
2017-08-07 19:11 ` [PATCH v2 1/8] Remove single-store shortcut Luc Van Oostenryck
2017-08-07 21:42 ` Linus Torvalds
2017-08-10 0:29 ` Christopher Li
2017-08-10 0:41 ` Luc Van Oostenryck
2017-08-10 0:53 ` Christopher Li
2017-08-10 11:01 ` Christopher Li
2017-08-10 12:26 ` Luc Van Oostenryck
2017-08-10 13:25 ` Christopher Li
2017-08-07 19:11 ` [PATCH v2 2/8] new helper: def_opcode() Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 3/8] reuse nbr_pseudo_users() Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 4/8] change the masking when loading bitfields Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 5/8] simplify ((A & M') | B ) & M when M' & M == 0 Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 6/8] transform (A & M) >> S to (A >> S) & (M >> S) Luc Van Oostenryck
2017-08-08 0:22 ` Christopher Li
2017-08-08 0:29 ` Luc Van Oostenryck
2017-08-08 1:48 ` Christopher Li
2017-08-08 1:00 ` Linus Torvalds
2017-08-08 1:38 ` Luc Van Oostenryck
2017-08-08 1:50 ` Christopher Li
2017-08-07 19:12 ` [PATCH v2 7/8] transform (A << S) >> S into A & (-1 " Luc Van Oostenryck
2017-08-07 21:54 ` Linus Torvalds
2017-08-07 22:08 ` Luc Van Oostenryck
2017-08-07 22:27 ` Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 8/8] fix: cast of OP_AND only valid if it's an OP_CAST Luc Van Oostenryck
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