From: Richard Earnshaw <rearnsha@arm.com>
To: Roland McGrath <mcgrathr@google.com>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] ARM: exclude fixed_regs for stack-alignment save/restore
Date: Tue, 24 Jul 2012 11:54:00 -0000 [thread overview]
Message-ID: <500E8CF5.5070205@arm.com> (raw)
In-Reply-To: <CAB=4xhr=LajhskDQ3YHqXeU7Ddhma7-hTJXTYVZ77xEregzoWQ@mail.gmail.com>
On 17/07/12 21:42, Roland McGrath wrote:
> Richard, here is the patch against the current trunk, as I promised
> last week in Prague. Please apply.
>
Done.
I've tweaked the comments slightly, but the functional modification is
unchanged.
R.
>
> Thanks,
> Roland
>
>
> gcc/
> 2012-07-17 Roland McGrath <mcgrathr@google.com>
>
> * config/arm/arm.c (arm_get_frame_offsets): Never use a fixed register
> as the extra register to save/restore for stack-alignment padding.
>
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index e2f625c..189f71e 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -16121,7 +16121,12 @@ arm_get_frame_offsets (void)
> else
> for (i = 4; i <= (TARGET_THUMB1 ? LAST_LO_REGNUM : 11); i++)
> {
> - if ((offsets->saved_regs_mask & (1 << i)) == 0)
> + /* While the gratuitous register save/restore is ordinarily
> + harmless, if a register is marked as fixed or global it
> + may be entirely forbidden by the system ABI to touch it,
> + so we should avoid those registers. */
> + if (!fixed_regs[i]
> + && (offsets->saved_regs_mask & (1 << i)) == 0)
> {
> reg = i;
> break;
>
next prev parent reply other threads:[~2012-07-24 11:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-14 17:23 Roland McGrath
2012-06-14 20:22 ` Mike Stump
2012-06-14 20:51 ` Roland McGrath
2012-06-15 0:44 ` Roland McGrath
2012-06-16 14:33 ` Richard Sandiford
2012-06-18 15:39 ` Richard Earnshaw
2012-06-18 16:56 ` Roland McGrath
2012-06-20 17:37 ` Roland McGrath
2012-07-17 20:42 ` Roland McGrath
2012-07-20 20:21 ` Roland McGrath
2012-07-24 11:54 ` Richard Earnshaw [this message]
2012-07-24 16:21 ` Roland McGrath
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