[rtems commit] doc: Clarify SPARC floating point ABI

Sebastian Huber sebh at rtems.org
Thu May 21 08:26:15 UTC 2015

Module:    rtems
Branch:    master
Commit:    a9c4f15dbe5d0db8727dc7a9c82fc9ffa00e8cb6
Changeset: http://git.rtems.org/rtems/commit/?id=a9c4f15dbe5d0db8727dc7a9c82fc9ffa00e8cb6

Author:    Alexander Krutwig <alexander.krutwig at embedded-brains.de>
Date:      Tue May  5 15:32:03 2015 +0200

doc: Clarify SPARC floating point ABI


 doc/cpu_supplement/sparc.t | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/doc/cpu_supplement/sparc.t b/doc/cpu_supplement/sparc.t
index d21e9fe..740643a 100644
--- a/doc/cpu_supplement/sparc.t
+++ b/doc/cpu_supplement/sparc.t
@@ -425,10 +425,15 @@ f4, ... f30)
 f8, ... f28)
 @end itemize
-The floating point status register (fpsr) specifies
+The floating point status register (FSR) specifies
 the behavior of the floating point unit for rounding, contains
 its condition codes, version specification, and trap information.
+According to the ABI all floating point registers and the floating point status
+register (FSR) are volatile.  Thus the floating point context of a thread is the
+empty set.  The rounding direction is a system global state and must not be
+modified by threads.
 A queue of the floating point instructions which have
 started execution but not yet completed is maintained.  This
 queue is needed to support the multiple cycle nature of floating

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