nor

NOR

nor RA, RS, RB

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

Encoding

Binary Layout

31

0:5

RS

6:10

RA

11:15

RB

16:20

124

21:30

/

31

 

Format X-form

Opcode 0x7C0000F8

Extension Base

Operands

• RA
  Target
• RS
  Src A
• RB
  Src B

Example

nor r4, r3, r5

Related

More in Base

Reference

View in PowerISA v3.1C Specification ↗ OPF Power ISA v3.1C

Description

Performs a bitwise NOR operation: RA ← ~(RS OR RB). Each bit position in RA is set to 1 if the corresponding bits in RS and RB are both 0, 0 otherwise. No condition registers or status fields are affected unless an extended form with a recorded bit is used (nor.).

Operation

RA ← ~(RS | RB)

Programming Note

The nor instruction performs a bitwise NOR of registers RS and RB and places the result in RA. Coding RB the same as RS forms the extended mnemonic not RA,RS, the standard way to complement a register. This instruction operates at user privilege level.