On Thu, 2025-06-05 at 14:23 +0200, Nicola Giuliani via Gcc-help wrote:
> Hi everybody,
>
> My name is Nicola Giuliani and I am a researcher in numerical analysis. I
> have encountered a strange behavior when compiling a very simple piece of
> code using g++. In this piece of code I link the InterlOneAPI MKL PARDISO
> solver and ask it to solve a linear system. I don't do any mathematical
> operation, I simply call the MKL libraries that I have dynamically linked.
I suppose MKL PARDISO is a set of open source libraries, whose source code you
could compile or statically analyze.
>
> This is the original compilation line I use
>
> g++ kernel_only_pardiso.cpp -m64 -L${MKLROOT}/lib -Wl,--no-as-needed
> -lmkl_intel_lp64 -lmkl_gnu_thread -lmkl_core -lgomp -lpthread -lm -ldl
> -I"${MKLROOT}/include" -o gnu_gnu.out
>
[...]
> https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/PARDISO-performance-fluctuation-on-INTEL-processor/m-p/1693601/emcs_t/S2h8ZW1haWx8bWVudGlvbl9zdWJzY3JpcHRpb258TUJCNzJMQ0ZJRUFWQ0J8MTY5MzYwMXxBVF9NRU5USU9OU3xoSw
Possible open source tools related to estimate accuracy of C or C++ code might
be:
https://frama-c.com/
(I have been employed and part of the team working on it; see
also https://arxiv.org/abs/1109.0779 and https://github.com/bstarynk/bismon that
I don't maintain anymore)
https://www-pequan.lip6.fr/cadna/
Perhaps they could help you to understand the issues.
https://www.absint.com/products.htm is selling related tools.
BTW did you observe (or can you reproduce) the following bug on GCC trunk (on
x86-64/Linux/Debian/Trixie)?
the https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120556 https://gcc.gnu.org/pipermail/gcc-bugs/2025-June/916978.html
Regards.
--
Basile STARYNKEVITCH <basile@xxxxxxxxxxxxxxxxx>
8 rue de la Faïencerie http://starynkevitch.net/Basile/
92340 Bourg-la-Reine https://github.com/bstarynk
France https://github.com/RefPerSys/RefPerSys
