[ADOL-C] Building ADOL-C with OpenMP-support

[Brad Bell]

Hello ADOL-C developers,

Using a special OpenMP memory manager turned out to greatly improve 
CppAD speed tests. This has enabled CppAD  to obtain near linear speed 
ups for 40 cores (we have not yet tested more cores). You many want to 
consider using the OpenMP memory manager that CppAD is currently using; see
     http://www.coin-or.org/CppAD/Doc/omp_alloc.xml


On 7/15/2011 12:59 AM, Kshitij Kulshreshtha wrote:
> Hello,
>
> As on 2011-07-13 17:09, Wolfgang Lorenz did write:
>> Hello list readers,
>>
>>
>> I just wanted to test the last stable version (2.2.0) of ADOL-C with
>> OpenMP support. The manual stated to configure ADOL-C using the option
>>
>>      --with-openmp-flag=<flag>
>>
>> In case of gcc that's "-fopenmp", which is working fine with other
>> projects. However, the build process ends with:
>>
>>      In file included from odedrivers.c:20:0:
>>      ../../../ADOL-C/src/taping_p.h:297:2: error: #error nicht hier
>>
>> The compiler error is still present in the trunk of ADOL-C svn. The
>> context in taping_p.h reads:
>>
>>           [...]
>>      296  #if defined(_OPENMP)
>>      297  #error nicht hier
>>           [...]
>>
>> Is OpenMP currently not supported, is this a bug or did I miss
>> something?
> Going from ADOL-C versions 2.1.* to 2.2.* we incorporated a new internal
> memory manager. This has caused several things to break, including
> OpenMP. Unfortunately for us the new memory manager was written by a
> colleague who is not involved in actively developing ADOL-C, so this
> #error is a programming relic which went uncommented and undetected
> until now. After some testing I found that the parallel initialization
> functions have not been ported to the new memory manager, which is why
> it was disabled.
>
> Please fallback to ADOL-C 2.1.12 for using openMP for now. I'll work on
> getting it to run with the new version soon.
>