Compiling with -ipo produces "unresolved" warning messages at link time on Cray systems
November 18, 2013 by Mike Stewart, NERSC USG (0 Comments)
Status: Reported to the darshan developers.
This bug affects only our Cray systems Edison and Hopepr and not Carver.
When a code is linked with the Intel -ipo (enable interprocedural optimization) flag on Hopper or Edison, many warning messages like this will be printed:
ipo: warning #11021: unresolved __real___xstat64
Referenced in libdarshan-posix.a(darshan-posix.o)
An executable will be produced.
-ipo is also part of the optimizations included with the Intel -fast optimization arguments, so you will see these error messages with -fast unless you include the NERSC recommended -no-ipo flag along with the -fast flag.
You can avoid these messages by disabling darshan by putting this in your .bashrc.ext (bash shell users) or .cshrc.ext (c shell users) files:
module unload darshan