From ripley at stats.ox.ac.uk  Wed Nov  5 19:39:51 2008
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Wed, 5 Nov 2008 18:39:51 +0000 (GMT)
Subject: [Rd] [R] Building with MKL on Ubuntu
In-Reply-To: <2bc7a5a50811051001j25ec2359x66009cd74852d9eb@mail.gmail.com>
References: <2bc7a5a50811041000u698ccbdm252e2209735192f1@mail.gmail.com>
	<alpine.LFD.2.00.0811041824550.10858@gannet.stats.ox.ac.uk>
	<1225827242.4910a3aace7b9@webmail.iarc.fr>
	<2bc7a5a50811050829o2904bddbw8be864d087096640@mail.gmail.com>
	<1225907974.10672.9.camel@seurat.iarc.fr>
	<2bc7a5a50811051001j25ec2359x66009cd74852d9eb@mail.gmail.com>
Message-ID: <alpine.LFD.2.00.0811051829330.24775@gannet.stats.ox.ac.uk>

You can't link 32-bit libraries into 64-bit code.

That test is not for accuracy but for compatible return conventions. 
What compilers are in use here?  We've seen several instances of gcc and 
icc not being compatible on x86_64 (Linux and Mac OS X: not surprising as 
gcc3 and gcc4 are also not compatible in their return conventions), and 
presumably MKL is compiled with icc.

Our experience with Intel compilers and MKL is uniformly negative -- less 
accuracy and usually slower runs.

On Wed, 5 Nov 2008, Anand Patil wrote:

> On Wed, Nov 5, 2008 at 5:59 PM, Martyn Plummer <plummer at iarc.fr> wrote:
>
>> It looks like the em64t version of MKL fails the test for the accuracy
>> of zdotu ("checking whether double complex BLAS can be used") and is
>> therefore dropped in favour of R's built-in BLAS.  I have just tested
>> this on Fedora and get the same result.
>>
>> The 32-bit MKL does work for me.
>>
>> Martyn
>>
>
> Many thanks, Martyn. The 64-bit index space is important to me, will I lose
> it if I link against the 32-bit MKL? Also, should I file a bug report with
> Intel?
> Anand
>
> 	[[alternative HTML version deleted]]
>
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>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595



[Rd] [R] Building with MKL on Ubuntu
Prof Brian Ripley