setnbc

Set Negative Boolean Condition

setnbc RT, BI

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

Details

Sets the target GPR to -1 (all bits set) if the specified condition register bit is set, otherwise sets it to 0. This instruction operates entirely on the CR and target register, with no side effects on other status fields.

Pseudocode Operation

if CR[BI] = 1 then RT ← -1 else RT ← 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