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

TNS Instruction Set Definition

HP NonStop S-Series Server Description Manual—520331-003

C-10

Instruction Definitions

Table C-2 presents symbolic definitions of the TNS instruction set for the NonStop

S-series processor, in numeric opcode order. Refer to Table C-1 for definitions of the

symbols used in this table. The one-character symbols immediately to the right of the

instruction opcodes have the following meanings:

Also:

Compatibility notes (such as “[See Note 1: CALLABLE PRIV]”) are referred to in some

of the definitions and are defined at the end of this table.

Optionally Indivisible On

Indicates that this instruction is atomic (use Indivisible on) in certain implementations

when required to do so. Otherwise it is normally implemented as nonatomic. Using

the instruction atomically is externally controlled by Accelerator translation options or

the special atomic modal instruction sequence.

Indivisible On

Indicates that this instruction sequence must complete without external interruptions.

Some exceptions are allowed. Page fault interrupts are allowed for some operations

that use a special RESTART POINT. It is an error for most TNS indivisible instructions

to encounter a page fault.

RESTART POINT

Restart points are a special implementation detail to allow mutex on to work properly.

It is a cooperation between trap handlers and the instruction to restart differently than

normal. Restart points are used by all optional atomic instructions to restart from the

beginning if there are any page faults during the operation.

* indicates privileged instruction.

@ indicates operating system use only.

C indicates that the instruction becomes temporarily privileged.

op(x) indicates that an operation similar to that performed by the instruction ‘op’

should be done using the value(s) ‘x’.