setnbc

Set Negative Boolean Condition

setnbc RT, BI

Sets RT to -1 if CR bit is set, else 0.

Details

The setnbc instruction sets the destination register RT to -1 if the specified bit BI in the Condition Register (CR) is 1. Otherwise, it sets RT to 0.

Pseudocode Operation

RT ← (CRBI = 1) ? -1 : 0

Programming Note

Use setnbc to conditionally set a register based on a specific bit in the Condition Register. Ensure CRBI is within valid range; otherwise, results are undefined. This instruction operates at user privilege level and does not generate exceptions under normal conditions.

Example

setnbc r3, 0

Encoding

Binary Layout
31
0
RT
6
BI
11
/
16
448
21
/
31
 
Format X-form
Opcode 0x7C000380
Extension Base
Registers Altered CR

Operands

  • RT
    Target
  • BI
    CR Bit