nor

NOR

nor RA, RS, RB

Bitwise NOR. RA = ~(RS | RB).

Details

The dcbtst instruction provides a hint that describes a block or data stream to which the program may perform a Store access, or indicates the expected use thereof. The nature of the hint depends on the value of the TH field.

Pseudocode Operation

Let the effective address (EA) be the sum (RA|0)+(RB).
if RA = 0 then b ←0
else           b ←(RA)
EA ←b + (RB)

Programming Note

The dcbtst instruction is used to provide a hint about data stream access patterns, which can help optimize cache behavior. It does not perform any actual memory operations; instead, it updates the system's view of the data stream. Ensure that the effective address calculation aligns with your intended use case for optimal performance. This instruction operates at the problem state and above.

Example

nor r4, r3, r5

Encoding

Binary Layout
31
0
RS
6
RA
11
RB
16
124
21
/
31
 
Format X-form
Opcode 0x7C0000F8
Extension Base

Operands

  • RA
    Target
  • RS
    Src A
  • RB
    Src B