From: Segher Boessenkool <segher@kernel.crashing.org>
To: Alexandre Oliva via Gcc-patches <gcc-patches@gcc.gnu.org>,
Alexandre Oliva <oliva@adacore.com>,
dje.gcc@gmail.com, richard.sandiford@arm.com
Subject: Re: [PATCH] [PR100106] Reject unaligned subregs when strict alignment is required
Date: Thu, 5 May 2022 08:50:23 -0500 [thread overview]
Message-ID: <20220505135023.GB25951@gate.crashing.org> (raw)
In-Reply-To: <mptk0b0csva.fsf@arm.com>
On Thu, May 05, 2022 at 08:59:21AM +0100, Richard Sandiford wrote:
> Alexandre Oliva via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> I know this is the best being the enemy of the good, but given
> that we're at the start of stage 1, would it be feasible to try
> to get rid of (subreg (mem)) altogether for GCC 13?
Yes please!
> We could do
> it target-by-target, with a target macro (yes, macro :-)) that opts
> in to keeping the existing behaviour. (subreg (mem)) would then be
> unconditionally invalid when the macro isn't defined. (Even in
> debug expressions, since those ought to narrow to a mem anyway.)
Or we can simply threaten to drop all unconverted targets. That way at
least there is a *chance* (a slim chance, but still) that the conversion
will ever be finished.
Paradoxical subregs of memory are already not allowed on targets with
instruction scheduling, btw.
Segher
next prev parent reply other threads:[~2022-05-05 13:52 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-05 6:52 Alexandre Oliva
2022-05-05 7:59 ` Richard Sandiford
2022-05-05 13:50 ` Segher Boessenkool [this message]
2022-05-06 10:57 ` [PATCH v2 2/2] " Alexandre Oliva
2022-05-09 8:09 ` Richard Sandiford
2022-05-05 14:33 ` [PATCH] " Segher Boessenkool
2022-05-06 2:41 ` [PATCH v2] " Alexandre Oliva
2022-07-09 17:14 ` Jeff Law
2023-05-24 5:39 ` Alexandre Oliva
2023-05-24 9:04 ` Richard Biener
2022-05-06 18:04 ` [PATCH] " Vladimir Makarov
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