Re: [eigen] glibc's malloc (x86-64) 16 byte aligned? |
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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] glibc's malloc (x86-64) 16 byte aligned?
- From: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
- Date: Mon, 25 Jan 2010 13:02:31 -0500
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uuuuhhhhh.....
indeed a quick test program shows that they are right... all my
pointers are 16 byte aligned...
Did that change in a recent version of glibc???
i'm using glibc 2.11.1.
Benoit
2010/1/25 Benoit Jacob <jacob.benoit.1@xxxxxxxxx>:
> oh!
> i didn't read correctly - "(or sixteen on 64-bit systems)"
>
> I think that's an error on their part. Here on linux x86-64 that's
> definitely not the case.
>
> Benoit
>
> 2010/1/25 Benoit Jacob <jacob.benoit.1@xxxxxxxxx>:
>> I don't understand?
>> on linux x86-64, malloc only returns 8-byte aligned pointers, and this
>> page confirms it.
>> Benoit
>>
>> 2010/1/25 Rohit Garg <rpg.314@xxxxxxxxx>:
>>> Hi all,
>>>
>>> http://www.gnu.org/s/libc/manual/html_node/Aligned-Memory-Blocks.html
>>>
>>> I was quite surprised to come across this. I never knew this was the
>>> case. I wrote a quick, dirty, non-comprehensive, non-exhaustive test
>>> and all of the malloc'ed pointers were 16 byte aligned.
>>>
>>> May be it's worth trying to run the eigen's test suite on linux x86-64
>>> assuming that the malloc is 16 byte aligned?
>>>
>>> Your thoughts?
>>>
>>> --
>>> Rohit Garg
>>>
>>> http://rpg-314.blogspot.com/
>>>
>>> Senior Undergraduate
>>> Department of Physics
>>> Indian Institute of Technology
>>> Bombay
>>>
>>>
>>>
>>
>