[PATCH] s390: increase default for max-pending-list-length

[Richard Guenther]

On Fri, Jan 8, 2010 at 3:59 PM, Wolfgang Gellerich
<gelleric@linux.vnet.ibm.com> wrote:
>
>
>
> Hello Everyone,
>
> The patch appended below increases a list maintained by the
> scheduler. Debugging a performance issue on s390 revealed that the
> former value was too small and prevented the scheduler expoiting its
> knowledge of data dependencies. Test is ok.

What about the impact on compile-time?

Richard.

> Regards, Wolfgang
>
> ---
> Dr. Wolfgang Gellerich
> IBM Deutschland Entwicklung GmbH
> Schoenaicher Strasse 220
> 71032 Boeblingen, Germany
> Tel. +49 / 7031 / 162598
> gellerich@de.ibm.com
>
> =======================
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> Changelog:
>
>
> 2010-01-08  Wolfgang Gellerich  <gellerich@de.ibm.com>
>
>        * config/s390/s390.c (override_options): Set
>        default of max-pending-list-length to 256
>
>
> Patch:
>
> ---
>  gcc/config/s390/s390.c |    3 +++
>  1 file changed, 3 insertions(+)
>
> Index: gcc-SVN/gcc/config/s390/s390.c
> ===================================================================
> --- gcc-SVN.orig/gcc/config/s390/s390.c 2010-01-08 15:07:40.000000000 +0100
> +++ gcc-SVN/gcc/config/s390/s390.c      2010-01-08 15:36:56.000000000 +0100
> @@ -1639,6 +1639,9 @@
>   if (s390_tune == PROCESSOR_2097_Z10
>       && !PARAM_SET_P (PARAM_MAX_UNROLLED_INSNS))
>     set_param_value ("max-unrolled-insns", 100);
> +
> +  set_param_value ("max-pending-list-length", 256);
> +
>  }
>
>  /* Map for smallest class containing reg regno.  */
>
>