Hi Chris,
On 07/08/15 07:06, Christopher Samuel wrote:
On 07/08/15 14:07, Christopher Samuel wrote:
I guess I'll wait for the build to complete and check it out.
No evidence of -march=native being passed through.
Upgraded from 2.1.1 to 2.2.0 by bootstrapping again in case it was a bug
in 2.1.1 but no difference.
Checked to "optarch=sandybridge" in our config file in case it was
confused by native, but again whilst eb seems to recognise the value it
stilldoesn't seem to get passed through to the actual build. :-(
Is this a bug, or am I missing something?
You will not see -march=native being used in the GCC build itself.
What EasyBuild will do is add -march=native to $CFLAGS (and friends)
when building something with a toolchain that uses GCC as compilers
(when optarch is set to True in toolchainopts, which it is by default).
When building something with the system (GCC) compiler, like you're
doing when bootstrapping GCC, $CFLAGS and co are not defined.
You can override what EasyBuild thinks it should use as compiler flag
corresponding to the optarch toolchain option via --optarch (or
optarch=x in your EasyBuild configuration file).
So, by using optarch=sandybridge, you're telling EasyBuild to add
-sandybridge to $CFLAGS when building something with a non-dummy
toolchain. That doesn't seem to be what you intend to do. ;-)
(the story with --optarch is different with Cray toolchains, but out of
scope here)
What Bart was saying is that he added 'configopts = ...' to the GCC
easyconfig file, which resulted in the extra configure flags to be used
when GCC is built.
regards,
Kenneth
