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Rename rounding modes and complete with fourth (#4455)

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Co-authored-by: ernestognw <ernestognw@gmail.com>
This commit is contained in:
Francisco
2023-07-13 17:52:03 -03:00
committed by GitHub
parent a55af77c75
commit 84db204a41
10 changed files with 210 additions and 173 deletions
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2
contracts/utils/Arrays.sol
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@ -33,7 +33,7 @@ library Arrays {
uint256 mid = Math.average(low, high);
// Note that mid will always be strictly less than high (i.e. it will be a valid array index)
// because Math.average rounds down (it does integer division with truncation).
// because Math.average rounds towards zero (it does integer division with truncation).
if (unsafeAccess(array, mid).value > element) {
high = mid;
} else {

37
contracts/utils/math/Math.sol
View File

@ -13,9 +13,10 @@ library Math {
error MathOverflowedMulDiv();
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
Floor, // Toward negative infinity
Ceil, // Toward positive infinity
Trunc, // Toward zero
Expand // Away from zero
}
/**
@ -100,8 +101,8 @@ library Math {
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
* This differs from standard division with `/` in that it rounds towards infinity instead
* of rounding towards zero.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
if (b == 0) {
@ -206,14 +207,15 @@ library Math {
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
if (unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
* towards zero.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
@ -256,12 +258,12 @@ library Math {
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
return result + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* @dev Return the log in base 2 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
@ -309,12 +311,12 @@ library Math {
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
return result + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* @dev Return the log in base 10 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
@ -358,12 +360,12 @@ library Math {
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
return result + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* @dev Return the log in base 256 of a positive value rounded towards zero.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
@ -401,7 +403,14 @@ library Math {
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
return result + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
}
}
/**
* @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
*/
function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
return uint8(rounding) % 2 == 1;
}
}