Analog Devices VISUALDSP++ 3.5 Manual page 170

C/C++ Compiler Language Extensions
A register set is a name for a specific set of commonly clobbered registers
that is predefined by the compiler. The following register sets are defined,
Set
CCset
MR
SR
B1set
B2set
Bset
DAG1scratch
DAG2scratch
DAGscratch
Dscratch
ALLscratch
When the compiler detects an illegal string, a warning is issued and the
default volatile set as defined in this compiler manual is used instead.
Unclobberable and Must Clobber Registers
There are certain caveats as to what registers may or must be placed in the
clobbered set.
On ADSP-219x processors, the registers
may not be specified in the clobbered set, as the correct operation of the
function call requires their value to be preserved. If the user specifies them
in the clobbered set, a warning will be issued and they will be removed
from the specified clobbered set.
1-132
Registers
ASTAT, condition codes
MR0 - MR2
SR0 - SR2
DAG1 B-registers
DAG2 B-registers
B1set union B2set
Members of dag1 I, L, B and M-registers that are scratch by default
Members of dag2 I, L, B and M-registers that are scratch by default
DAG1scratch union DAG2scratch
Members of D-registers that are scratch by default
Entire default volatile set
VisualDSP++ 3.5 C/C++ Compiler and Library Manual
, , ,
I4 I5 DMPG2 MSTAT
for ADSP-219x DSPs
, and
M_MODE