Patchwork [PR50572] Tune loop alignment for Atom

login
register
mail settings
Submitter Sergey Ostanevich
Date Oct. 19, 2011, 12:26 p.m.
Message ID <CAGYS_TLEnJC1UC3yM1T_0ygzt+DmpDxQ-==snGHJ4OKx_Ge-sw@mail.gmail.com>
Download mbox | patch
Permalink /patch/120611/
State New
Headers show

Comments

Sergey Ostanevich - Oct. 19, 2011, 12:26 p.m.
On Wed, Oct 19, 2011 at 4:14 PM, Uros Bizjak <ubizjak@gmail.com> wrote:
>
> You can just change the default in processor_target_table.
>
> Uros.
>

Will it be applicable during optimizations for size? It will hurt,
although not much (see PR).
New patch is below. Ok for trunk as obvious?

Sergos

2011-10-19  Sergey Ostanevich  <sergos.gnu@gmail.com>

	* gcc/config/i386/i386.c (ix86_option_override_internal): use loop
	align by 16 bytes for Atom platform
Uros Bizjak - Oct. 19, 2011, 12:46 p.m.
On Wed, Oct 19, 2011 at 2:26 PM, Sergey Ostanevich <sergos.gnu@gmail.com> wrote:

>> You can just change the default in processor_target_table.
>>
>> Uros.
>>
>
> Will it be applicable during optimizations for size? It will hurt,
> although not much (see PR).

Looking at the code, I'd say that we don't handle -Os in different way.

> New patch is below. Ok for trunk as obvious?
>
> Sergos
>
> 2011-10-19  Sergey Ostanevich  <sergos.gnu@gmail.com>
>
>        * gcc/config/i386/i386.c (ix86_option_override_internal): use loop
>        align by 16 bytes for Atom platform

Please update ChangeLog, like:

* gcc/config/i386/i386.c (processor_target_table): Change Atom
align_loop_max_skip to 15.

> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 2c53423..8c60086 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -2596,7 +2596,7 @@ static const struct ptt
> processor_target_table[PROCESSOR_max] =
>   {&bdver1_cost, 32, 24, 32, 7, 32},
>   {&bdver2_cost, 32, 24, 32, 7, 32},
>   {&btver1_cost, 32, 24, 32, 7, 32},
> -  {&atom_cost, 16, 7, 16, 7, 16}
> +  {&atom_cost, 16, 15, 16, 7, 16}
>  };


OK.

Thanks,
Uros.

Patch

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 2c53423..8c60086 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2596,7 +2596,7 @@  static const struct ptt
processor_target_table[PROCESSOR_max] =
   {&bdver1_cost, 32, 24, 32, 7, 32},
   {&bdver2_cost, 32, 24, 32, 7, 32},
   {&btver1_cost, 32, 24, 32, 7, 32},
-  {&atom_cost, 16, 7, 16, 7, 16}
+  {&atom_cost, 16, 15, 16, 7, 16}
 };