sparc erc32 FPU confusion
Kenneth J. Peters
Kenneth.J.Peters at jpl.nasa.gov
Wed May 31 01:02:17 UTC 2006
I noticed that running some of the tests (sp19, tm26) on RTEMS 4.6.6
erc32 that floating point was not tested. Digging in, I see that
make/custom/erc32.cfg changed from 1.27 to 188.8.131.52 (current version)
>-CPU_CFLAGS = -mcpu=cypress
>+CPU_CFLAGS = -mcpu=cypress -msoft-float
> # optimize flag: typically -0, could use -O4 or -fast
> # -O4 is ok for RTEMS
and this seems to be from the PR827 patch file. However, that same
patch file has:
>diff -Naurb rtems-4.6.4/cpukit/score/cpu/sparc/rtems/score/sparc.h
> 2003-09-04 20:47:40.000000000 +0200
> 2005-09-12 10:56:58.000000000 +0200
>@@ -66,11 +66,7 @@
>-#define SPARC_HAS_FPU 0
> #define SPARC_HAS_FPU 1
> #if SPARC_HAS_FPU
> #define CPU_MODEL_NAME "w/FPU"
and this change is NOT reflected in either the 4.6.6 release version
of sparc.h (184.108.40.206) or the current CVS version of sparc.h (1.12)!
QUESTION 1: Should sparc.h be changed to always define SPARC_HAS_FPU
according to the patch?
QUESTION 2: If so, are there other parts of the patch that have not
made it into the current RTEMS package? I have not tried to figure
this out yet.
QUESTION 3: Why the change to less optimization and -msoft-float? I
don't see any explanation. Were there bugs found? Or can I optimize
fully and ditch soft-float? If so, should this be changed back in the
CVS tree and releases?
I have not looked at the leon sparc BSPs to see if this same thing is
going on there.
Ken.Peters at jpl.nasa.gov
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