From: Jeff Law <law@redhat.com>
To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com
Subject: Re: [PATCH 5/5] Remove CANNOT_CHANGE_MODE_CLASS workaround in i386.c
Date: Fri, 19 Sep 2014 17:54:00 -0000 [thread overview]
Message-ID: <541C6DB5.8010006@redhat.com> (raw)
In-Reply-To: <874mw5ns0x.fsf@e105548-lin.cambridge.arm.com>
On 09/18/14 04:26, Richard Sandiford wrote:
> Patch 4 should make it possible to relax i386'a CANNOT_CHANGE_MODE_CLASS,
> solving the missed optimisation that triggered the original thread.
>
>
> gcc/
> * config/i386/i386.c (ix86_cannot_change_mode_class): Remove
> GET_MODE_SIZE (to) < GET_MODE_SIZE (from) test.
>
> Index: gcc/config/i386/i386.c
> ===================================================================
> --- gcc/config/i386/i386.c 2014-09-15 09:48:11.310438531 +0100
> +++ gcc/config/i386/i386.c 2014-09-15 09:48:11.310438531 +0100
> @@ -37526,13 +37526,6 @@ ix86_cannot_change_mode_class (enum mach
> the vec_dupv4hi pattern. */
> if (GET_MODE_SIZE (from) < 4)
> return true;
> -
> - /* Vector registers do not support subreg with nonzero offsets, which
> - are otherwise valid for integer registers. Since we can't see
> - whether we have a nonzero offset from here, prohibit all
> - nonparadoxical subregs changing size. */
> - if (GET_MODE_SIZE (to) < GET_MODE_SIZE (from))
> - return true;
> }
>
> return false;
>
OK.
jeff
next prev parent reply other threads:[~2014-09-19 17:54 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-18 10:07 [PATCH 0/5] Fix handling of word subregs of wide registers Richard Sandiford
2014-09-18 10:09 ` [PATCH 1/5] Allow *_HARD_REG_SET arguments to be const Richard Sandiford
2014-09-19 6:14 ` Jeff Law
2014-09-18 10:10 ` [PATCH 2/5] Tweak subreg_get_info documentation Richard Sandiford
2014-09-19 6:16 ` Jeff Law
2014-09-18 10:13 ` [PATCH 3/5] Use simplify_subreg_regno in combine.c:subst Richard Sandiford
2014-09-19 6:17 ` Jeff Law
2014-09-18 10:25 ` [PATCH 4/5] Generalise invalid_mode_change_p Richard Sandiford
2014-09-19 17:53 ` Jeff Law
2014-09-22 7:34 ` Richard Sandiford
2014-09-22 16:29 ` Jeff Law
2014-09-18 10:26 ` [PATCH 5/5] Remove CANNOT_CHANGE_MODE_CLASS workaround in i386.c Richard Sandiford
2014-09-19 17:54 ` Jeff Law [this message]
2014-09-19 6:14 ` [PATCH 0/5] Fix handling of word subregs of wide registers Jeff Law
2014-09-19 7:24 ` Richard Sandiford
2014-09-19 15:59 ` Jeff Law
2014-09-19 17:14 ` Jeff Law
2014-09-22 7:23 ` Richard Sandiford
2014-09-22 10:49 ` Ajit Kumar Agarwal
2014-09-22 11:26 ` Richard Sandiford
2014-09-22 12:07 ` Ajit Kumar Agarwal
2014-09-22 9:00 ` Andrew Pinski
2014-09-22 11:29 ` Richard Sandiford
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