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Re: [PATCH] Atom: Scheduler improvements for better imul placement
On Wed, Apr 11, 2012 at 5:38 PM, Andi Kleen <andi@firstfloor.org> wrote:
> Igor Zamyatin <izamyatin@gmail.com> writes:
>
>> Hi All!
>>
>> It is known that imul placement is rather critical for Atom processors
>> and changes try to improve imul scheduling for Atom.
>>
>> This gives +5% performance on several tests from new OA 2.0 testsuite
>> from EEMBC.
>>
>> Tested for i386 and x86-64, ok for trunk?
>
> Did you measure how much this slows down the compiler when compiling
> for Atom? The new pass looks rather slow.
No, since this "pass" is applied rarely. Conditions are mentioned in
the comments to ix86_sched_reorder
>
> -Andi
>
> --
> ak@linux.intel.com -- Speaking for myself only