# ffs

Finds the first set bit.

### Synopsis

`int ffs( uint32 mask )`

### Description

ffs finds the lowest-numbered bit that is set in the argument. The least-significant bit is bit number 1, and the most-significant bit is bit 32.

### Arguments

flags
  The 32-bit word to check

### Return Value

ffs returns zero if no bits are set in the parameter, or the bit index of the first bit is set in the parameter. For example, ffs returns 1 if the value of the argument is 1 or 3 or 7; and 3 if the value of the argument is 4 or 12. If no bits are set, ffs returns 0.

### Implementation

Convenience call implemented in clib.lib V20.

### Associated Files

clib.lib
  ARM Link Library

### Notes

This entry point is provided for portability and compatibility only; code written specifically for Portfolio should use FindLSB() or FindMSB() to reduce any ambiguity over whether the least-significant or most-significant bit is desired.

### See Also

``FindMSB`(), FindLSB()`