Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Thu, 30 Sep 2004 14:53:16 -0500

Laznovsky, Michael wrote:

Hi again- now that I know it's the "-mstrict-align" that's causing the
byte operations, I still have 2 questions...
1) I see that this switch is provided by EPICS/base/config/CONFIG.Vx.mv2400:
 ARCH_DEP_CFLAGS = -mcpu=604 --no-builtin -mstrict-align -mlongcall
 What's the proper way to override this in a local work area config directory?

You should be able to just include a new definition of ARCH_DEP_CFLAGS in
your Makefile, inside an architecture test comparing $(T_A) against your
specific target arch.
2) What switch (or lack of) does this compiler need to turn this feature off?
   A quick naive test of re-running just the gmake-generated ccpcc command without
   the mstrict switch makes the assembly phase barf, though I'm easily convinced
   that this may be due to the lack of proper environment caused by running it
   in isolation:

Correct, the R3.14 build system sets up some environment variables that
tell the compiler where to find its components.
You should read this tech-talks message first though, which describes why
we added that -mstrict-align flag in the first place:

http://www.aps.anl.gov/epics/tech-talk/2000/msg00529.php
You can discover whether your compiler includes the fix for that original
problem by running

<tornado>/host/<arch>/bin/ccppc -v

If you find the number 28373 in the output from that command you *may* be
ok to omit the -mstrict-align in that our original bug *probably* wont recur.
- Andrew
--
Dear God, I didn't think orange went with purple until I saw
the sunset you made last night.  That was really cool. - Caro

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System