From: Richard Henderson <rth@redhat.com>
To: Tom de Vries <Tom_deVries@mentor.com>
Cc: Steve Ellcey <sellcey@mips.com>,
Andrew Pinski <pinskia@gmail.com>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] Fix PR55876 - Make generation of paradoxical subreg in widen_operand more robust
Date: Mon, 07 Jan 2013 17:48:00 -0000 [thread overview]
Message-ID: <50EB0A5D.1000302@redhat.com> (raw)
In-Reply-To: <50EAA074.3050402@mentor.com>
On 01/07/2013 02:16 AM, Tom de Vries wrote:
> - /* If MODE is no wider than a single word, we return a paradoxical
> - SUBREG. */
> + /* If MODE is no wider than a single word, we return a
> + lowpart or paradoxical SUBREG. */
> if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD)
> - return gen_rtx_SUBREG (mode, force_reg (GET_MODE (op), op), 0);
> + {
> + if (GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (op)))
> + return gen_lowpart_SUBREG (mode, op);
> + else
> + return gen_rtx_SUBREG (mode, force_reg (GET_MODE (op), op), 0);
> + }
Is there any good reason we're using gen_rtx_SUBREG directly here?
Seems like this sort of logic would be present in plain gen_lowpart,
generating the paradoxical subreg that we want.
r~
next prev parent reply other threads:[~2013-01-07 17:48 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <50EA9FDD.6000803@mentor.com>
2013-01-07 10:16 ` Tom de Vries
2013-01-07 17:48 ` Richard Henderson [this message]
2013-01-14 14:44 ` Tom de Vries
2013-01-15 17:12 ` Richard Henderson
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