On 03/20/12 01:17, Nikos Chantziaras wrote:
> On 19/03/12 16:11, Andrew Lowe wrote:
>> On 03/19/12 17:39, Nikos Chantziaras wrote:
>>> On 19/03/12 07:26, Andrew Lowe wrote:
>>>> Hi all,
>>>> Has anyone played around with the various "better known" compilers on
>> [snip]
>> ...
>> ...
>> [snip]
>>>
>>> You don't need to "change" compilers. You can use whatever one you like
>>> to build your program. The compiler portage uses to build its packages
>>> does not affect your own usage of the others.
>>>
>>> As for the fastest one, I can only speak for Intel CPUs where Intel C++
>>> gives me the fastest binaries.
>>>
>>>
>>>
>> Nikos,
>> Your experience with Intel is what I'm after. Aster, the FEA code I'm
>> going to use is not in Portage hence I will be using it's own build
>> system. When you've used Intel, have you just exported "CC="icc" or
>> something similar, as make.conf won't be used? Also, I've read somewhere
>> that there are libraries that you have to link against that are specific
>> to the Intel compiler as it does not create libraries that are
>> comparable with the gcc produced ones - is this true or does the
>> compiler now "play well" with the gcc world?
>
> No special libs required. The binaries I get (both C and C++) don't use
> anything extra. I checked both with "ldd" as well as with lsof at
> runtime (in case it dlopens anything).
>
> For building, you use "CC=icc" and "CXX=icpc" for regular makefiles or
> autoconf scripts. I mostly use qmake though (I use Qt for my GUIs). In
> that case, you call qmake like this:
>
> qmake -spec linux-icc
>
> and it creates a makefile that will use ICC. This is also an example of
> ICC using C and C++ libs (Qt is C++) that were built by GCC without
> issues; its ABI is fully GCC compatible.
>
> There are way to use ICC for portage too. I tried that once. It worked
> quite well. But I didn't went with it since too much of a bother.
>
> Note that the link Florian posted is a bit outdated. For example the
> sections that tells you that "binaries compiled with icc won't work
> after icc is uninstalled" is not true. They will work just fine. The
> exception of course if when you specifically use an ICC library, like
> the Intel math kernel library.
>
>
>
Thanks for that. The library question was the reason I didn't proceed
with playing around with icc ages ago. Your experience tells me it's now
rectified.
Andrew
