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Re: [patch] Excessive alignment in ix86_data_alignment

On Thu, Oct 9, 2014 at 1:37 AM, Uros Bizjak <> wrote:
> On Thu, Oct 9, 2014 at 10:25 AM, Kirill Yukhin <> wrote:
>> On 08 Oct 23:02, Petr Murzin wrote:
>>> Hi,
>>> I have measured performance impact on Haswell platform according to this
>>> input:

Kirill, please mention:

in your ChangeLog.

> What about older processors?

Kirill, please collect data on Nehelam/Westmere, Sandybrigde/Ivybride
and Silvermont.

> The optimization was introduced well before Haswell for then current
> processors, and it was based on the recommendation from Intel
> optimization guide. If this optimization doesn't apply for new
> processors, then tune option should be introduced and set accordingly.

I believe the original excessive alignment was introduced by cut/paste

to improve x86 FP performance, which might be partially copied from


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