popcntbd (Population Count Byte Doubleword) instruction
Purpose
Allows a program to count the number of one bits in a doubleword.
Note: The popcntbd instruction is supported for POWER5™ architecture
only.
Syntax
| Bits | Value |
|---|---|
| 0 - 5 | 31 |
| 6 - 10 | RS |
| 11 - 15 | RA |
| 16 - 20 | /// |
| 21 – 30 | 122 |
| 31 | / |
POWER5™
Description
The popcntbd instruction counts the number of one bits in each byte of register RS and places the count in to the corresponding byte of register RA. The number ranges from 0 to 8, inclusive.
The popcntbd instruction has one syntax form and does not affect any Special Registers.
Parameters
| Item | Description |
|---|---|
| RS | Specifies source general-purpose register. |
| RA | Specifies destination general-purpose register. |