System Debug Reference Manual (32650-90888)

Chapter 6 235
System Debug Command Specifications M-X
MR
The following registers are known as the General Registers .
The following registers are pseudo registers. They are not defined in the
Precision Architecture, but are terms used in the Procedure Calling
Conventions document and by the language compilers. They are provided
for convenience. They are computed based on stack unwind information.
They may not be modified.
Table 6-1. General Registers
Name Alias Access Description
RO none d A constant 0
R1 none dm General register 1
R2 none dm Used to hold RP at times
R3 none dm General register 3
[vellip]
R22 none dm General register 22
R23 ARG3 dm Argument register 3
R24 ARG2 dm Argument register 2
R25 ARG1 dm Argument register 1
R26 ARG0 dm Argument register 0
R27 DP dM Global data pointer
R28 RET1 dm Return register 1
R29 RET0 dm Return register 0
SL dm Static link
R30 SP dM Current stack pointer
R31 MRP dm Millicode return pointer
Table 6-2. Pseudo Registers
Name Alias Access Description
RP none d Return pointer (not the same as R2)
PSP none d Previous stack pointer