User`s guide

User Commands 4–129
User Commands
rmode
The following table displays the DIGITAL UNIX Alpha microprocessor register
usage.
If you enter the command without a parameter, then the current mode is displayed.
The rmode setting is stored in battery-backed RAM.
Hardware
Register
Name
Software
Register
Name Use and Linkage
r0 v0 Used for expression evaluation and to hold integer
function results.
r1...r8 t0...t7 Temporary registers; not preserved across procedure
calls.
r9...r14 s0...s5 Saved registers; their values must be preserved
across procedure calls.
r15 FP or s6 Frame pointer or a saved register.
r16...r21 a0...a5 Argument registers; used to pass the first six integer
type arguments; their values are not preserved across
procedure calls.
r22...r25 t8...t11 Temporary registers; not preserved across procedure
calls.
r26 ra Contains the return address; used for expression
evaluation.
r27 pv or t12 Procedure value or a temporary register.
r28 at Assembler temporary register; not preserved across
procedure calls.
r29 GP Global pointer.
r30 SP Stack pointer.
r31 zero Always has the value 0.