Re: [patch RFA] backport the fix for PR rtl-optimization/37769 to 4.3

["Richard Guenther" <richard dot guenther at gmail dot com>]

On Sat, Nov 1, 2008 at 5:43 AM, Kaz Kojima <kkojima@rr.iij4u.or.jp> wrote:
> This patch fixes PR rtl-optimization/37769 for the 4.3 branch.
> It's backported from the patch for the trunk:
>
> http://gcc.gnu.org/ml/gcc-patches/2008-10/msg00662.html
>
> which is already applied and it looks there are no problems.  It's
> tested with bootstrap and the top level "make -k check" with no new
> failures both on i686-pc-linux-gnu and powerpc-apple-darwin9.5.0.
> Ok for the 4.3 branch?

It looks like this is a regression on the 4.3 branch (though it isn't
marked as such - please
make sure to mark regressions appropriately in bugzilla).  So the
patch is ok (and in
general you needn't ask for approval for backporting regression fixes).

Thanks,
Richard.

> Regards,
>        kaz
> --
> 2008-11-01  Kaz Kojima  <kkojima@gcc.gnu.org>
>
>        Backport from mainline:
>        2008-10-24  Kaz Kojima  <kkojima@gcc.gnu.org>
>
>        PR rtl-optimization/37769
>        * regmove.c (optimize_reg_copy_2): Update REG_INC note if needed.
>
> --- ORIG/gcc-4_3-branch/gcc/regmove.c   2008-02-20 06:48:51.000000000 +0900
> +++ LOCAL/gcc-4_3-branch/gcc/regmove.c  2008-10-25 08:12:25.000000000 +0900
> @@ -686,7 +686,16 @@ optimize_reg_copy_2 (rtx insn, rtx dest,
>              {
>                if (reg_mentioned_p (dest, PATTERN (q)))
>                  {
> +                   rtx note;
> +
>                    PATTERN (q) = replace_rtx (PATTERN (q), dest, src);
> +                   note = FIND_REG_INC_NOTE (q, dest);
> +                   if (note)
> +                     {
> +                       remove_note (q, note);
> +                       REG_NOTES (q)
> +                         = gen_rtx_EXPR_LIST (REG_INC, src, REG_NOTES (q));
> +                     }
>                    df_insn_rescan (q);
>                  }
>
>