NonStop S-Series Server Description Manual (G06.24+)

TNS Execution Modes
HP NonStop S-Series Server Description Manual—520331-003
6-63
Subprocedure Calls
Figure 6-34. Subprocedures Return Values Through Sublocal Data Area
S Register
BSUB Instruction
P Register
to subprocedure
Parameters
P Register
Data Area
Return P
S Register
After BSUB
Before BSUB
Before BSUB
After BSUB
Memory stack while
subprocedure executes
Sublocal
Variables
S Register
Current top
element of
memory stack
Sublocal data
addressed S-minus-
relative (including
parameters)
S Register
S Register
Parameters Deleted
RSUB Instruction
P Register
P Register
Code Area
S register must be
decremented, pointing
at return P before RSUB
BSUB + 10
RSUB 5
BSUB + 10
Subprocedure
RSUB 5
S Register
Before PUSH
S Register
1
2
P1
P3
Return P
P2
P4
P1
P3
Return P
P2
P4
VST299.vsd