[daip] Moving user files

[Eric Greisen]

Roderick Johnstone writes:

 > The Intel compiler is well known for having tons of high-level 
 > optimizations switched on by default. Thats one reason its produces code 
 > that runs so fast. At one time it used to miscompile a lot of stuff, but 
 > that was version 7.x.
 > 
 > Ideally, what you should do is send the compiler switches to make fat 
 > binaries. These have two or three sets of machine code and take a 
 > run-time decision which is the best to use. That way you get to have 
 > code that runs full speed on the P4 using all its whizzy instructions 
 > but also has generic code that will run on anything.
 > 
 > This is documented in:
 > http://www.intel.com/cd/software/products/asmo-na/eng/219281.htm
 > http://www.intel.com/cd/software/products/asmo-na/eng/222300.htm
 > 
 > Using a compiler switch something like -axNP, would be good (exact 
 > options depend on which version of the compiler you have). This makes a 
 > binary with generic x86 code (ax) and code optimised for P4 sse, sse2 
 > (N) and sse3 (P). There are several possibilities for N and P, see first 
 > html reference above. K would optimise for Athlon XP, but you can only 
 > have 2 letters so someone has to make a decision which things to 
 > optimise for!
 > 
 > So, could I request please either:
 > 
 > 1) You consider rebuilding aips with something like -axNP or -axKN

    I will look at this but it may take time.  We tried a bunch of
other stuff that did not work so it will take serious testing.

We tell the compiler (version 9.0)
   COMPSWIT="-c -xW -w90 -w95 -cm -ip -save -align all"
   OPT0='-O0'; OPT1='-O3'; OPT2='-O3';
and the linker
   LINK="-lsvml -Vaxlib -L/usr/local/lib -O3 -static-libcxa -save -align all"
and the C compiler
   OPT0="-O3 -xW -ip"
   COMP="-c $OPT0 -I$INC -D_FILE_OFFSET_BITS=64 -DHAVE_LINUX_GLIBC"


 > 
 > 2) You send me instructions on turning my binary aips installation into 
 > a source code compiled one. Do I need to delete my 31DEC05 directory and 
 > download the source afresh, and build or can I somehow coax the system 
 > into rebuilding my binary intallation, given that I probably have to 
 > tell it how to use a custom compiler? The default version we have is gcc 
 > 3.4.3.

cd $AIPS_ROOT
source LOGIN.CSH
$CDTST

This is pretty easy - cd to your $SYSLOCAL and edit CCOPTS.SH,
LDOPTS.SH, and FDEFAULT.SH.  They select the compiler - choose 3.4.3
which should be fine (3.4.2 had problems we found that they fixed in
3.4.3).  In $SYSLOCAL, rename RSYNC.ME which is the flag that tells
the MNJ to use rsync.

cd $TST/$ARCH/INSTALL
rm *.LIS *.LOG
rm $LIBR/*/SUBLIB
INSTEP2
INSTEP4

and you are done in, depending on the machine, 1-4 hours.  This is
probably better than running generic code from Intel.  My experience
was that it ran no faster than the GNU code.

Eric Greisen