cflag and fflag in makefile
 

I have two makefile file. I can't understand which one I will run.
I am using Red Hat 4.1.2-42 with gcc version 4.1.2 and ifort version 10.1

file1:
CFLAGS = -O
FFLAGS = -O1 -FI

file2:
CFLAGS = -O -xHost -fp-model precise
FFLAGS = -O0 -xHost -FI -fp-model precise

mainly I want to know about -FI, -xHost, -fp-model precise this three term.


Thank you

-xHost seems to be an Intel compiler specific flag (first hit on google: http://marklodato.github.io/)
-fp-model precise http://software.intel.com/sites/prod...n_fp_model.htm

no you are NOT
there is NO version of RHEL 4 called 4.1.2-42
there is the old RHEL 4.1
of which ONLY the very last minor upgrade is supported -- RHEL 4.9
and that is on EXTRA extended life support
-- as in you have to pay red hat extra CASH $$$

also it would be rather difficult to install Gcc 4.1 on the ancient rhel4.1


can you please post the output of this
that will tell us what you are running