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Date: Sun, 6 Sep 2015 13:20:44 +0200
From: magnum <john.magnum@...hmail.com>
To: john-dev@...ts.openwall.com
Subject: Re: Large stack alignment

On 2015-09-05 20:48, magnum wrote:
> On 2015-09-05 04:47, Solar Designer wrote:
>> Guess not confirmed.  We use buffers on the stack, and they are properly
>> aligned for 128-bit SIMD.  This is unreliable for AVX2 and above, though.
>
> Are you sure it's unreliable? As far as I can google it, gcc had
> problems with large alignments but it was fixed long before 4.7, which
> is the minimum version you need to even build for AVX2.
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=16660
> http://stackoverflow.com/questions/841433/gcc-attribute-alignedx-explanation

So Lei reminded me of this:
http://www.openwall.com/lists/john-dev/2015/08/24/8

We have an issue for changing all stack allocs using MEM_ALIGN_SIMD to 
align ourselves.

magnum

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