# CountBits

Counts the number of bits set in a word.

### Synopsis

`int CountBits(uint32 mask);`

### Description

CountBits examines the longword passed in as a parameter and returns the number of bits that are turned on in the word, using an algorithm derived from a note in MIT's HAKMEM.

### Arguments

mask
  The data word to count the bits of.

### Return Value

The number of bits that were turned on in the supplied value.

### Implementation

Convenience call implemented in clib.lib V21.

### Associated Files

string.h
  ANSI C Prototype

clib.lib
  ARM Link library

### See Also

``FindMSB`(), FindLSB()`

#