[Llvm-bgq-discuss] Problems with binaries compiled with anything else than -O0

[Thomas Heller]

Hi List,

We are currently trying to streamline our BGQ support for HPX. As it turns 
out, our builds segfault at right at the beginning in some static 
initialization segment of a dynamic library when compiling our code with -O3 
(in fact, anything else above -O0 leads to the same segfault). Everything 
works splendid when doing the same with -O0. Unfortunately, I was not able to 
extract a simple enough testcase to reproduce the problem yet. I was wondering 
if there is a list of compile flags added when going from -O0 to -O1 which 
might be the culprit. I am running out of ideas here... I was thinking about 
LTO, but it is not explicitly enabled in our builds.

Hope someone can help,
Thomas