From: Eric Botcazou <ebotcazou@adacore.com>
To: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: Richard Biener <rguenther@suse.de>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
Jeff Law <law@redhat.com>, Jakub Jelinek <jakub@redhat.com>
Subject: Re: [PATCH] Fix unaligned access when predictive commoning (PR 71083)
Date: Tue, 09 Aug 2016 20:48:00 -0000 [thread overview]
Message-ID: <7783559.v48Yu3xPbD@arcturus.home> (raw)
In-Reply-To: <AM4PR0701MB2162F9A6F39A908B01FB6D4DE41C0@AM4PR0701MB2162.eurprd07.prod.outlook.com>
> I think from Eric's comment in get_inner_ref it can be possible
> in Ada that the outer object is accidentally byte-aligned
> but the inner reference is not. In that case I think it is
> better to generate a BIT_FIELD_REF instead of a COMPONENT_REF.
The patch says get_bit_range instead... The comment therein means that
bitfields can be nested in Ada: you can have a bitfield in a record which is
itself a bitfield in another record.
> Eric do you agree? Are there any Ada test cases where the
> pcom optimization jumps in?
According to the comment, data-ref analysis punts on bit offsets so I'm not
sure how boff can be not byte-aligned.
--
Eric Botcazou
next prev parent reply other threads:[~2016-08-09 20:48 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-08 19:57 Bernd Edlinger
2016-08-09 7:29 ` Richard Biener
2016-08-09 17:31 ` Bernd Edlinger
2016-08-09 20:48 ` Eric Botcazou [this message]
2016-08-09 22:23 ` Bernd Edlinger
2016-08-10 8:47 ` AW: " Bernd Edlinger
2016-08-10 12:19 ` Eric Botcazou
2016-08-10 12:29 ` Richard Biener
2016-08-10 16:24 ` Bernd Edlinger
2016-08-11 7:07 ` Richard Biener
2016-08-11 10:09 ` Bernd Edlinger
2016-08-11 10:30 ` Richard Biener
2016-08-11 19:47 ` [PATCH] Increase alignment for bit-field " Bernd Edlinger
2016-08-12 7:13 ` Richard Biener
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