BitMath
This library provides functionality for computing bit properties of an unsigned integer
Functions#
mostSignificantBit#
function mostSignificantBit( uint256 x ) internal pure returns (uint8 r)Returns the index of the most significant bit of the number, where the least significant bit is at index 0 and the most significant bit is at index 255
The function satisfies the property: x >= 2mostSignificantBit(x) and x < 2(mostSignificantBit(x)+1)
Parameters:#
| Name | Type | Description |
|---|---|---|
x | uint256 | the value for which to compute the most significant bit, must be greater than 0 |
Return Values:#
| Name | Type | Description |
|---|---|---|
r | unit8 | the index of the most significant bit |
leastSignificantBit#
function leastSignificantBit( uint256 x ) internal pure returns (uint8 r)Returns the index of the least significant bit of the number, where the least significant bit is at index 0 and the most significant bit is at index 255
The function satisfies the property: (x & 2leastSignificantBit(x)) != 0 and (x & (2(leastSignificantBit(x)) - 1)) == 0)
Parameters:#
| Name | Type | Description |
|---|---|---|
x | uint256 | the value for which to compute the least significant bit, must be greater than 0 |
Return Values:#
| Name | Type | Description |
|---|---|---|
r | unit8 | the index of the least significant bit |