Turnoff prefetching for -march=znver1

Message ID DM2PR12MB0137C7D2468EE7E84186E27385DF0@DM2PR12MB0137.namprd12.prod.outlook.com
State New
Headers show

Commit Message

Stepanyan, Victoria Feb. 2, 2016, 8:28 p.m.
Hi Maintainers,

This patch disables prefetching for -march=znver1 which is turned on by default.

gcc/ChangeLog:

2016-02-02 Victoria Stepanyan <victoria.stepanyan@amd.com>

	* gcc/config/i386/x86-tune.def: Disable default prefetching for -march=znver1

Ok for trunk?

Victoria

Comments

Uros Bizjak Feb. 2, 2016, 8:49 p.m. | #1
On Tue, Feb 2, 2016 at 9:28 PM, Stepanyan, Victoria
<Victoria.Stepanyan@amd.com> wrote:
> Hi Maintainers,
>
> This patch disables prefetching for -march=znver1 which is turned on by default.
>
> gcc/ChangeLog:
>
> 2016-02-02 Victoria Stepanyan <victoria.stepanyan@amd.com>
>
>         * gcc/config/i386/x86-tune.def: Disable default prefetching for -march=znver1
>
> Ok for trunk?

OK.

Thanks,
Uros.
Kumar, Venkataramanan Feb. 4, 2016, 7:55 a.m. | #2
Hi Uros,

> -----Original Message-----

> From: Uros Bizjak [mailto:ubizjak@gmail.com]

> Sent: Wednesday, February 03, 2016 2:20 AM

> To: Stepanyan, Victoria

> Cc: gcc-patches@gcc.gnu.org; gerald@pfeifer.com; rguenther@suse.de;

> Kumar, Venkataramanan

> Subject: Re: Turnoff prefetching for -march=znver1

> 

> On Tue, Feb 2, 2016 at 9:28 PM, Stepanyan, Victoria

> <Victoria.Stepanyan@amd.com> wrote:

> > Hi Maintainers,

> >

> > This patch disables prefetching for -march=znver1 which is turned on by

> default.

> >

> > gcc/ChangeLog:

> >

> > 2016-02-02 Victoria Stepanyan <victoria.stepanyan@amd.com>

> >

> >         * gcc/config/i386/x86-tune.def: Disable default prefetching for -

> march=znver1

> >

> > Ok for trunk?

> 

> OK.


Thank you. I up streamed it on behalf of Victoria.
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=233127


> 

> Thanks,

> Uros.


Regards,
Venkat.

Patch

--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -218,7 +218,7 @@  DEF_TUNE (X86_TUNE_FOUR_JUMP_LIMIT, "four_jump_limit",
    at -O3.  For the moment, the prefetching seems badly tuned for Intel
    chips.  */
DEF_TUNE (X86_TUNE_SOFTWARE_PREFETCHING_BENEFICIAL, "software_prefetching_beneficial",
-          m_K6_GEODE | m_AMD_MULTIPLE)
+          m_K6_GEODE | m_ATHLON_K8 | m_AMDFAM10 | m_BDVER | m_BTVER)

/* X86_TUNE_LCP_STALL: Avoid an expensive length-changing prefix stall
    on 16-bit immediate moves into memory on Core2 and Corei7.  */